FR2478144A1 - SYSTEM FOR FEEDING AND INSERTING A FRAME WIRE IN A WEAVING MACHINE - Google Patents

Abstract

INVENTION RELATING TO WEAVING. IMPROVEMENTS IN A WEAVING TRADE, CONSISTING OF GUIDING A PREDETERMINED LENGTH OF WEFT YARN F THROUGH THE GROUND OF YARNS SA INSIDE A GUIDE TUBE, CONSISTING OF A MULTIPLICITY OF SEGMENTS 41, WHICH FIT AND COMES OUT OF EVERY CROWD. AN APPROPRIATELY ESTABLISHED AND POWERED NOZZLE N PRODUCES A PULSATION OF AIR WHICH DRIVES THE SAID LENGTH OF WIRE F, PREVIOUSLY DOSED AND STORED ON A ROTATING DEBTOR. APPLICATION TO THE PERFORMANCE OF TRADE OPERATING AT VERY HIGH SPEED.

Description

The present invention, concerning weaving, is more specifically

relating to a weaving system

  by means of a loom, in which the thread of

  is inserted through the crowd of the loom by means of a jet of pulsed air or other gaseous fluid under pressure (a system which will be called thereafter, generally, weft insertion by l 'air) and she is

  relating, more particularly, to a system of information

  frame weft through the air that works in a way that

  which is likely to have a speed of insertion

  very high air jet, through the craft crowd, in comparison with existing systems, with a corresponding reduction in the actual insertion times of the weft, so as to adapt the system to high weaving

speed.

  As regards the prior art, it can first be said that in all weaving a web is divided

  initially flat longitudinal warp threads

  nally in at least two interleaved groups which are

  trimmed in opposite directions from the starting plane so as to define between the groups of separated warp threads an elongated diamond-shaped space, known as a "crowd", through which the weft is inserted , the directions of the separate warp groups being inverted in a given order after each frame by the movement of a harness, so that the warp threads are sinuously intertwined around the

  successive weft threads so as to form the fabric.

  Traditionally, the weft is supported, wound on a bobbin body held inside a shuttle,

  and as weaving progresses, the na-

  vette is moved alternately forwards and backwards through the shed on the upper surface of a beam-like flapper bearing a comb, which protrudes from it upwards and rotates alternately in one direction and the other to push or "beat" each new frame by means of the comb against the working end or clamping line of the pick

  tissue being woven. With the tradition

  nel, the propulsion of the coil was carried out by means of so-called sabers which are mounted on the loom in the vicinity of the opposite side edges of the chain so as to pivot by their ends

  lower and which are operated in such a way as to

  natively by their upper ends against the shuttle. It is evident that this classical conception suffered from inherent limitations as to the speed of

  shuttle that could be obtained and was also

  marked disadvantages; examples include a deafening operation noise, the risk of saber breakage or other damage to equipment and the danger to the personnel who dealt with it when,

  as it happened occasionally, the shuttle escapes

  from his box and became an uncontrolled projectile.

  In order to overcome these difficulties inherent in bobbin weaving, various other means have been contemplated in the prior art and, in the last decade or so, there has been an increasing interest in propelling the weft into the crowd by means of spooling. a jet of fluid. Water jets were found to be a blowing agent that could be controlled more or less, but water

  possible cause of corrosion and limits the choice of

  the wire; this is why it is particularly

  tageux to use a gaseous fluid. If, in theory, it is also possible to use gases other than air, cost considerations make it necessary to choose compressed air as the only practical propellant; consequently, this mode of weaving will be designated later, for convenience, under the name of "weft insertion by air", the use of other gases being implied with the same term. In the invention, it will also be possible to use

  moist air, possibly preheated.

  In general, projection techniques by

  the air that has been used in previous systems of

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  frame weft by air fall into two categories

  fundamental. In one, the frame end is initiated

  tially projected by means of pressurized air supplied by a nozzle, located externally and in the vicinity of one side of the warp shed, which serves to initially accelerate the weft end and circulates through

  a crowd. the propulsion forces of the existing nozzles

  aunts are severely limited by length

  the end of the weft that can be reached

  dre and that is why with this solution we foresee a

  multiplicity of additional jet nozzles or "reinforcing

  at intervals staggered in the crowd, said nozzles being inserted therein and being extracted from various

  ways out of the inside of the crowd and through

  valleys between the warp threads. All of the propulsion forces of this succession of multi-stage nozzles may be sufficient to propel the wire of

  frame over the entire width of the craft.

  While this concept has been shown to be generally feasible in practice, it also has certain disadvantages, including the need for

  carefully adjust over time the succession of

  tuyerations, as well as excessive consumption

  compressed air and therefore poor performance.

  In order to avoid having reinforced thrusters

  at certain intervals in the crowd, we imagined

  another solution using only one nozzle of

  external sertion, cooperating with a "frame guide tube" located in the crowd. As during weaving the groups of chain yarns must move up and down next to each other, it is

  out of the question that a continuous body

  inside the crowd during the formation of the crowd.

  This is why we will use a "discontinuous" guide tube,

  constituted by a multiplicity of generically shaped segments

  annular web, each of which has a sufficiently narrow thickness in the axial direction so as to pass between the 24781 4 neighboring warp son arranged in axially aligned locations, so as to constitute a total tubular piece, interrupted in its length, which covers almost the entire width of the crowd. Each annular segment has an exit aperture, similar to a slot, at a point of its periphery, to allow lateral evacuation of the inserted weft yarn.

  when the guide tube is retracted under the crowd.

  When the weft yarn is thrown by the outer nozzle

  in one end of this disconnected guide tube.

  tinu, the projection force printed on the wire by the nozzle

  the distance the weft yarn is propelled by this force can be greatly increased in comparison with the use

of the nozzle alone.

  The reasons why the discontinuous guide tube increases the projection force of the nozzle are not fully understood at present. the

  neighboring segments of this tube are separated by

  vales sufficient to allow pressurized air, feeding one end of the tube, to disperse into the external atmosphere, while the outer edges of the segment piercing must be present,

  considerable resistance to friction in the movement

  a jet of air passing through them; from this point of view, the effect of such a tube could be expected to be negative. Moreover, the ambient air could be driven from the surrounding atmosphere into the interior of the tube through the same intervals between segments, with the possible effect of increasing the propulsive forces. In any event, it is an established fact that the addition of a weft guide tube as broadly described above appreciably increases the distance from which a weft yarn can be projected to the

  by means of a jet of compressed air supplied by a nozzle.

  With this second kind of insertion system

  air weft, many improvements have been proposed.

  tions which, in general, focused on refinements of various aspects of the system, including the increase of the effect of the guide tube, for example by the use of

  provisions capable of temporarily reducing the

  valle between its segments during the insertion phase

  frame of the cycle or by the development of

  aerodynamic issues for these elements, by optimizing the supply of a frame length

  measured in the insertion nozzle by means of various

  Measuring and weft storage devices which are designed to reduce the resistance of the frame length to the propulsion and to consequently use, with the best possible advantage, the thrust capacity of a given nozzle, etc. rare exceptions, the research of the prior art on this kind of system took very

  little consideration of the fundamental behavior of the

  feed air itself.

  According to the aerodynamic theory, it is known that the thrust force (d?) Applied by a current

  gaseous displacement to an element, disposed to its

  of given unit length (dx) and circumference (t D), is determined by the relation: d? = C * 1/2? (Vg-Ve> 2 "D * dx (I) formula where P represents the density of the gaseous fluid, Cf a factor varying with the state of the element, factor which is roughly constant for a given wire, V is the velocity of the fluid, Ve the speed of the element and D the diameter of

  item. In a given system, the diameter and

  They will ordinarily be fixed; as a result, the thrust force is essentially a function of the density of the fluid and the square of the difference in the velocities of the moving gaseous fluid and the element. When we insert the

  frame in the crowd of a craft, the frame will be normal-

  stationary before insertion, so that

  is zero and the initial push force consequently

  quent is essentially proportional to f V 2 The practical application of this result is somewhat complicated by the generally contrary behavior

  speed and density in the system in question.

  tion. At speeds below that of sound (the speed

  of the sound being referred to as "Mach 1" 1), the speed varies with the square root of the pressure of load, so that for example to double the speed the pressure must

  to be quadrupled. For a given load pressure,

  as the air accelerates in the nozzle, the pressure drops and

  accompanied by a decrease in density following the rela-

  apply to adiabatic phenomena. When V reaches the velocity of sound at the throat of the nozzle, the rate g p deyient eX atetmAenteal to that of VV and thus of variation of xVg after its maximum value at the coi for a given supply pressure. At all speeds above the speed of sound, e decreases more rapidly than V does. From Mach 1 to Mach 1,414 the relative modification rates are such that v continues to grow, whereas above Mach 1,414 pdccreases at rates sufficiently larger than the growth of Vg, so that HV 2 becomes larger. small, so that for example V Vg is about the same at Mach 2 as at

Mach 1.

  When the charging pressure is increased, V increases as indicated until the speed of sound is reached, but subsequent increases

  load pressure produce only increases in

  This means that the maximum velocity at the highest pass is Mach 1, regardless of the increases in

  pressure that only serve to make the gas more dense.

  Gas acceleration at a supersonic speed is only possible by increasing the volume of the downstream space

  of the neck to allow the denser gas to

  to tend and to decrease P, and consequently makes the increase of Vg realizable. If the nozzle neck opens directly into the surrounding atmosphere, the gas can relax at random for a short distance, whereas if the nozzle

24781 44

  has a convergent contour section below the

  neck (thus forming what is called a supersonic nozzle

  that) the gas can relax in a controlled manner.

  For gas velocities exceeding Mach 1 downstream of the neck, the pressure increase required for a given modification of the Mach number is a rather geometric rather than a linear function. For example, the theoretical ratio of the pressure pressure to ambient pressure for Mach 1 is about 1.9, for Mach 1.414, it is

  of about 3.25 / 1, for Mach 2 of about 7.9 / 1 and

  tick it should be a little higher.

  According to these technical considerations, it appears

  clearly that the increase in V resulting from a

  increase of the charge pressure seems definitive-

  not very promising starting from the economic return

  the increase in the push force dF in the rela-

  above, because below the sonic velocities

  given theoretical increase of V requires an increase

  charge pressure as the square of the differential

  the difference between the variation in

  the load pressure even worsens, at speeds exceeding that of sound. In addition, the velocity of the gas at the neck can in no case exceed the speed of sound and the essential thrust force p V 2 itself is subject to a limiting value for the

  low level of Mach 1,414 and then it can only de-

  Cliner. At this apparent technical disadvantage of the coet

  high nozzle pressures, it is necessary to add the neces-

  practice that the pressurized air used for

  the frame must be free from contaminations

  such as oil and dust particles.

  Obtaining this clean air requires special centrifugal compressors and / or particular filtering devices which substantially increase the investment.

  in hardware of a given installation.

  For these and other reasons, researchers

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  Prior art designers working on weft insertion systems have all accepted the principle of a low pressure air supply and a small air jet speed as unavoidable conditions and have striven to use these given conditions with a

  maximum efficiency, focusing on other technologies

as indicated.

  In each weaving operation, each cycle

  weaving is divided into two main phases,

  see the frame insertion phase that usually occurs

  at the end of the swinging movement of the wing backwards and the threshing phase, which occurs when the wing is swung forward, towards the other limit of its arcuate course, so as to chase or beat the newly inserted weft end (or duite) against the previously tightened fabric draw line, the fabric

  being advanced in stages as it is necessary for

  hold said clamping line in a fixed place. We have

  made various attempts to shorten the phase of

  to increase the weaving speed

  using, for example,

  Mechanical design designed to accelerate movement

  of the wing during threshing and swinging

  constructed with shortened swivel brackets

  and reduced mass, so as to shorten the arc of de-

  placing the wing and decreasing the forces of inertia

  involved in its propulsion and all this can be advan-

  geous. But there are limitations inherent in the reduction, thus obtained, of the duration of threshing; consequently, obtaining a very high speed operation of the craft, that is to say of the order of

  1000 weft insertions or picks per minute are not

  only possible by taking less time to insert the frame itself. Specifically, for 1000 picks per minute, a total of only 60 milliseconds is available for an entire weft insertion or launch cycle, that is, the elapsed time of a

24 78144

  hype to the next. Normally, the prior art air weft insertion systems require at least 60 milliseconds for frame insertion alone, not to mention the threshing phase, and these systems are therefore, by their nature, limited in speed of operation. It currently exists in the textile industry,

  in operation or capable of functioning, several

  lions of shuttle crafts that have been designed to

  at speeds of up to 150 to 200 picks per minute and can not be adapted to

  high speed without rebuilding them practically

  ment. But, with quite a few mechanical modifications, these crafts can walk at speeds of around 400

  cycles per minute. At this speed, the corresponding period

  to a complete cycle is 150 ms and in theory

  frame insertion time of the order of 5D to 60 ms,

  storing the prior art, could be tolerated in a

  cycle of this duration. Nevertheless, with time to insert

  of this order of magnitude, the functioning of the

  would become quite critical because of the great

  portion of the total cycle time absorbed by the insertion time and may require special "rest motions" for this purpose. Therefore, it would be decidedly advantageous, if converting existing shuttle looms into weft insertion looms, that the weft insertion time be lowered well.

  below the level of the prior art, so as to

  to allow greater flexibility in the operation of these trades and to remove them from critical operation.

  This being the case, to explain the invention we

  only if a compressible gas feeds a nozzle that converges at a certain point on an opening or on a neck with a minimum cross-sectional area, and if the

  pressure acting on the gaseous fluid gradually increases

  the velocity of the gas at the neck can be at most equal to the speed of sound, and any further increase in the pressure on the gas serves only to increase the density of the gas stream, without any increase in the speed of the gas above the speed of sound. Under these conditions, the nozzle is said to be "quenched" and the minimum ratio of the pressure pressure to the ambient pressure for which this quenching state occurs.

is equal to approximately 2.

  Now, in the invention, it has been discovered that, contrary to

  to any reasonable expectation, if in a system

  weft insertion including a guide tube

  continuous, a converging weft insertion nozzle is supplied with air at a pressure higher than that required to smother the nozzle neck for a continuous duration

  set, in fact the nozzle is able to effectively use

  the air pressure energy to transport the weft, allowing the projection thereof in the craft crowd in a period of time substantially lower than those of the prior art systems of this kind and it

  becomes possible to avoid excessive energy consumption

  sive by modulating the outlet pressure of the nozzle without appreciably reducing the possibility of transport

of the frame.

  Therefore, the ultimate object of the invention is to provide an improved system for insertion of

  frame by air, which is adapted to be used indifferently

  to convert existing shuttle looms as well as a new, specially designed loom, and this system is characterized by improved operation and reliability, with reduced fuel consumption

the energy of the compressed air.

  Another object of the invention is to provide a weft insertion air nozzle which is designed to

  ability to transmit maximum thrust to the frame.

  Another object of the invention is to provide an actuation control unit for the insertion nozzle.

  an improved frame, which can be excited, either electrically

24781 44

  mechanically, and that allows accelerated and reproducible response times with precision for

the triggering of the nozzle.

  Still another object of the invention is to provide an improved weft and storage dosing unit capable of automatically supplying the insertion nozzle with a length of weft accurately adapted to the width of the loom without resorting to instrumentation instruments. complex control. Still another object of the invention is to provide improved mounting of a discontinuous weft guide tube

  in the crowd, which actually acts to retract posi-

  the guide tube automatically out of the

  f5ule during the threshing movement of the wing.

  The subject of the invention is also a device

  lifting-extracting frame used to remove positive-

  the inserted weft of the guide tube in response to

threshing of the wing.

  Another object of the invention is to manufacture

  an improved fabric edge using a combination of

  of a gauze edge weave and a neighboring pair of twisted tie yarns that hold the

  quality of the selvedge without damage.

  Another object is constituted by a sup-

  Improved port of the frame receiving tube, which rule

  automatically the position of this tube, so as to

  hold against the path of the frame throughout the cycle

weaving.

  These results and benefits will be exposed more

  in detail by the detailed description below, given

  without limitation, with reference to the drawings, in which: FIG. 1 is a very schematic perspective view of the essential constituents of a

  profession incorporating the present invention.

  Figures 2A and 2B are detail views

24 78 1 44

  enlarged, looking through the left end of the bat-

  both of the art of FIG. 1, respectively in the rear weft insertion position and in the forward threshhold position, showing the compound motion of the weft guide tube. Figure 3 is an enlarged detail view of the upper part of the leaf in the threshing position

  as in Figure 2E, which shows the device for

  weft removal in projected position in solid line and retracted position for weft insertion into

mixed line.

  FIG. 4 is a detailed and enlarged view of a weft insertion nozzle, according to an embodiment according to the invention, in cross-section through

the axis of the nozzle.

  Figure 5 is a cross-section, similar to

  ble in FIG. 4, of a weft insertion nozzle,

  according to a modified embodiment.

  Fig. 6 is a diagram showing an electronically controlled air control unit for the

insertion nozzle of the invention.

  Fig. 7 is a waveform diagram, illustrating the operation of the control unit of

Figure 6.

  FIG. 8 is a perspective view through

  the front of an air control unit, acting mechanically

  to control the weft insertion nozzle, the housing being represented by its contour and the passage

  of air, schematically in the form of a duct.

  FIG. 9 is a sectional view from above of the mechanical control unit of the nozzle of FIG. 8, the casing being shown in cross section and the FIG.

rotating cylinders, in plan.

  FIG. 10 is a somewhat schematic vertical section of the control unit of FIGS. 8 and 9,

  showing details of his rotating cylinders.

  Fig. 11 is a side perspective view

247814 4

  of a modified air control unit, functioning

  canically, to pilot the insertion nozzle of the in-

  vention, the housing being shown only by its outline

  and the air ducts appearing schematically indi-

* that. FIG. 12 is a somewhat schematic vertical section of the modified control unit of FIG.

11, including the housing.

  Fig. 13 is a waveform diagram

  illustrating the operation of the mechanical control unit

Figures 11 and 12.

  Fig. 14 is a side elevational and partly cross-sectional view of a weft and flow rate metering unit, according to one embodiment

Using a rotating drum.

  FIG. 15 is an end view of the dosing and flow unit of FIG. 14, partially broken away

  to show the inside of the associated air ring.

  Fig. 16 is a side elevational view, partially in cross-section, of a modified metering and flow unit using a stationary winding drum. FIG. 17 is an end view, partly in section, of the modified dosing and flow unit of FIG.

figure 16.

  Fig. 18 is a detail view of a frame receiving tube shape with engagement pliers

associated frame.

  Fig. 19 is a detailed view of a modified frame receiving tube incorporating photoelectric detection devices which signal the arrival of

the frame end.

  Figure 20 is a schematic air circuit

  for a preferred embodiment of the invention.

  Fig. 21 is a circuit diagram

  for a preferred embodiment of the invention.

  FIG. 22 is a graph on which the arrival times of the air and the weft relative to the supply pressure are plotted over a range of 276 to 827 kPa relative to a supersonic profiled nozzle,

  of 11 mm2 with and without extension tube, having

  equal to 5, 10 and 20 times the output diameter

of the nozzle.

  FIG. 23 is a graph similar to FIG. 22 for three non-profiled nozzles which have respective neck areas of 11, 16 and 32 mm 2 without tubes

extender.

  FIG. 24 is a schematic view showing

  schematically the arrangement for simulating an air weft insertion system of the prior art.

  FIG. 25 is a comparative graph, similar to that of FIG. 23, but showing the operation of a simulation of a frame insertion system by

  the air of the prior art using nozzles

with variable neck area.

  FIG. 26 is a comparative graph providing the air and weft arrival times with respect to the actual stagnation of the nozzle or the charge pressure provided by the simulation of the prior art of FIG. 24, with the same only to the graph of FIG. 25. FIG. 27 is a representation similar to that of FIGS. 22 and 23 of the system of the invention which compares the weft arrival times over a range of supply pressures from 207 to Relative 827 kPa for supersonic profiled nozzles ranging from Mach 1.5 to Mach 2.07 with and without extension tube, the length of which would be five times the outlet diameter of the nozzle, supplied by air supplied by an accumulator

  high capacity, the Mach 1.5 nozzle also operating

  with a low-capacity accumulator for a purpose

comparison.

  Figures 28A-28I are reproductions of

  traces of pressure, obtained with the oscillograph, which

247814 4

  the changes in the charging pressure

  the time in air pulsations generated by the 11 mm2 non-profiled collar area nozzle of Figure 23, operating at intervals of 69 kPa / 68.95 kPa over the pressure range of 'alimenta-

from 276 to 827 kPa.

  FIGS. 29A to 29I are reproductions of pressure traces similar to those of FIGS. 28A to 28I, but for a non-profiled exhaust nozzle of FIG.

  16 mm2 neck and on a different scale. -

  FIGS. 30A to 30I are reproductions of pressure traces similar to those of FIGS. 28A to I and 29A to I, but for the unshaped airfoil nozzle

  neck 32 mm2 and at the same scale as in Figure 29A.

  Figs. 31A-31I are comparative reproductions of pressure traces similar to those of Figs. 28A-28I, but on a different scale for the

  prior art simulation of Figures 24 and 25, in use

  reading a non-profiled nozzle with a neck area 11 mi.

  FIGS. 32A to 32I are comparative reproductions of pressure traces similar to those of FIGS. 29A to 29I, but on a different scale for the previous simulation with an unformed nozzle.

16 mm2 neck area.

  FIGS. 33A to 33I are comparative reproductions of pressure traces similar to those of FIGS. 30A to 30I, but at a different scale for the prior art simulation with an unformed nozzle.

neck area 32 mm2.

  Figure 34A is a reproduction, from

  load pressure as a function of time and at a

  the still different, a pressure trace generated by the preferred nozzle of the system of the invention, equipped

  additional feeding capacity or

  accumulator; while Figure 34B - - - - - -

  is a reproduction of a pressure trace for the same

  system without any additional power supply capability

  or accumulator and illustrating the change over time of the peak pulse pressure at the lower feed capacity, compared to the

pulsation of Figure 34A.

  Figure 35 is a reproduction of a "band

  "real" graph produced by a multi-oscilloscope

  lanes controlling a work cycle of a loom according to the invention according to the preferably balanced mode of operation and showing corresponding waveforms

  at the nozzle neck pressure, at the actuation of the

  output rate rage, at the supply voltage of the

  frame, and at the arrival of the frame to the receiving tube.

  Figure 36 is an enlarged detail plan view.

  die of a fragment of the edge of the fabric produced by the invention, revealing the combination of binding yarns

  twisted with gauze border weave.

  Figure 37 is a detailed view of a device

  mechanical tif to produce the opening of the clamp and to close the switches that allow the adjustment

  precise moment of their actuation.

  The field of the invention is fundamentally conventional in most of its construction and operation (to some extent adapted to better fulfill the conditions here required) and the structure of the trade is visible schematically in the overall view of Figure 1 ; we will describe it in a general way using alphabetical markers and only with enough

  details to establish the material of the present improvements

  rations. As usual, the warp threads are suppor-

  at the ends W on a chain beam (not

  sible) which is rotatably mounted and,

  from there, go through the eyelets of pa-

  I parallel wire rods, arranged in two or more separate groups and held in parallel parallel planes by corresponding h-frames H. The h-frames are mounted so as to be able to move back and forth to up and down,

24781 44

  so that the groups of warp threads are separated

  res to form an elongated, diamond-shaped, seated crowd S, the front angle of which is defined by the line of

  tightening E of the fabric that is being woven.

  In front of the hoop frames H is placed in the width a flapper beam B below the lower plane of the chain, the beam B being mounted at its ends on substantially vertical supports L known as hunting swords, which are pivotally mounted. on a tree A at their lower ends and that can be rocked

  in one direction and the other through means of

  not shown, for example by means of a crankshaft. A comb R, having the form of a set of parallel wires located in a same plane, mounted on the flat plates of the frame, with the warp threads passing in their intervals, protrudes upwardly from the rear side of the frame. beating, so as to push each new frame against the clamping line when the leaf pivots forward. The fabric once woven

  is collected in a conventional manner on a beam

not shown.

  The fabric has a coarse or fringed edge Q, because the weft is continuously inserted into the warp shed on the same side thereof rather than alternatively from its opposite sides as is done from habit in shuttle weaving. This coarse edge can be cut with scissors or knives K for this purpose in working position on the

  clamping line and actuated in the usual way.

  According to the invention, the wing B of the

  craft is equipped with a segmen-

  discontinue so as to facilitate, in a manner known per se, the evacuation of the weft son F through the shed, the guide tube constituting an obstacle by

  interpenetration with the frame ends in the lsin-

  the crowd when the wing is in its most rearward position and out of the crowd, while the wing is moving forward. Preferably, the leaf carries a lifting and extraction device

  frame, designated in the set by 0, so as to move

  positively frame the inserted frame F and remove it from the guide tube. the weft is projected into the discontinuous guide tube by means of a puff or pulsation of air emitted by a weft insertion nozzle N which is mounted on

  beating it close to one side of the crowd, while the

  The free frame of the inserted weft is received beyond the far side of the shed, inside a vacuum receiving tube carried by the opposite end of the leaf and, if desired, it is gripped by an associated clip. to this tube. Preferably, the tube is supported with the possibility of displacement so as to follow the path of the frame during threshing. The receiving tube may include photoelectric detection means (not visible) for detecting the arrival of the frame at that location and transmitting a control signal in the absence of the frame. The

  production of the air pulsation by the nozzle is controlled

  accurately by means of an excision control unit.

  tion of the nozzle, which is activated at

  terminated in relation to the cyclical operation of the craft. A suitable length of weft is extracted from a weft roll or other source P and is made available for the insertion nozzle N by means of a metering and threading unit M, arranged at a location fixed externally to the insertion nozzle N and a clamping means C is interposed between the metering unit M and the nozzle N to positively grasp the frame F at a given moment.

  determined in connection with the insertion action.

  We will now describe individually the

  components of the system that have

new features.

  I. (a) the installation according to the invention comprises firstly a mechanism for retraction of the discontinuous guide tube

which is particular.

  In a traditional trade, the shutter is constituted

2478,144

  The upper surface of the beam is, in the rear weft insertion position, substantially co-planar with the wires forming the lower side or floor of the shed, which is killed by a large, massive truss running the full width of the loom. The shuttle can slide on the beam as it passes through the crowd. In the field of the present invention, the volume of the flap beam is expandable, keeping only one frame of the beam and

  for example by having the shape of a channel 39 which is-

  green up and that is attached to the ends of the

  hunting swords B, as is necessary to support the

  mechanically the various components, including

  took the discontinuous or segmented frame guide tube

  of the invention. As has been said, this tube T is

  tituated by an axial alignment of annular segments min-

  these 41 (which are best seen in Figures 2A and 2B), which preferably have an axial thickness of not more than about 2.5 cm to allow their introduction upwards into the interior of the crowd S by the intervals

  between the warp threads W without eroding or otherwise

  donmmager the chain, and an annular thickness appropriate to the mechanical strength, for example 0.6 to 0.9 cm. Each tube segment 41 has a radial extension 43

  forming a foot projecting from a peri-

  to allow the elements to be mounted, axially aligned and spaced, on a common base 45, directed transversely, in which

  the ends of the extension 43 are fixed or incor-

  porées. Each weft thread F is projected during the

  by the internal bore 47, of predetermined diameter

  0, the axial alignment of the annular segments 41 and the lateral escape of the weft yarn out of the alignment of the segments when it is extracted from the crowd, by a narrow gap 49 formed in each segment at a point common device on its sector

or upper back dial.

  In the known arrangements of the prior art, the discontinuous guide tube is fixed relative to the leaf. It is obvious in any case that the elements of the guide tube must be completely extracted from the inside of the crowd S before the comb R reaches the threshing position to allow the frame F to float freely inside. of the crowd before being pushed against the tightening line E of the fabric by the forward movement of the comb R. In general,

  the provisions of the prior art usually required

  a certain variation of the normal arcuate path of the leaf so as to obtain in time a retraction of the guide tube, for example, by tilting the leaf and the block comb forward towards the line E

  fabric. But this means that the comb presents an inclination

  considerable momentum in its threshing position, which implies that the force driving the wire against the line E is applied at an angle, relative to the plane of said line, by moving the wire downwards at the same time as it is pushed forward against the line E, which can cause deformations of the fabric, while in the conventional design of the loom, the arched path of the upper leaf end is more or less symmetrical vis-à-vis a vertical plane, so as to provide the best compromise between the preferably horizontal position of the leaf during the weft insertion and the preferably vertical position of the comb

in the threshing position.

  In the present invention, the structure of the leaf is modified to incorporate a frame

  allowing the relative vertical displacement of the tube of in-

  frame sertion. The design of the frame is not critical and can take various forms. For example, each hunting sword may be provided with a pair of collars 53, spaced in the vertical direction and aligned

  axially for slidingly receiving a sliding rod

  55 through the openings in the bottom

  channel 39 (Figure 1) and attached at its upper end

  than the support base 45 of the insertion tube T. The

  ends of the base 45 are connected to the upper ends

  In the first embodiment of FIGS., there are substantially vertical bars 51 which pivot at their lower ends on the frame of the loom on a pivot axis 54 spaced rearwardly with respect to the pivot axis A of the sword swords I 1. As a result, when the leaf pivots, the upper ends of the drive bars 51 turn on a more inclined arc indicated by the double arrows, than the upper ends of the X-hunting swords producing the vertical displacement of the base of the adjustment tube 45 and therefore the guide tube T itself, with respect to the flapper channel 39. In this way, during threshing, the guide tube T has a compound movement, pivoting

  following an arch with the fly while moving himself

  same vertically and the point of its complete retraction out of the crowd may therefore vary as desired, regardless of the position of the wing B, by adjusting the

  position of the lower pivot axis 54 of the drive bar

  51 with respect to the pivot axis A of the hunting swords L. The premature retraction of the guide tube T during threshing e advantageous by providing a better opportunity for the warp son to restore against any deformation in their normal position, as a result of the extraction between them segments 41 of the guide tube. It has been found that if the tube is fixed relative to the leaf and that its retraction is thus delayed, the warp threads (which must shift laterally somewhat to allow the passage of the segments of the guide tube) can be maintained in

  such a position which is discarded at the moment when the weft is

  against the line of the fabric and remain "stuck" in this wrong position, when the crowd collapses

  during the inversion of the groups of his sons of chain.

  This gives rise to defects that can be observed in the

  uniform spacing of the warp yarns in the resulting tissue

  so, producing a streaked or "combed" fabric, such defects normally being indicative of the use of too thick comb elements.

  By choosing the position of the slot or

  outlet valle 49 (FIGS. 2A and 2B) in the segments of the guide tube 41 along their peripheral portion

  higher, the movement should preferably be considered

  composed of the guide tube T, which includes both

  the vertical component and the usual arcuate component

  the. Thus, the smaller the vertical displacement of the guide tube, the closer the position of the exit slot 49 is to the lower end of the segment dial.

  upper neighbor of comb R and vice versa.

  The segments 41 of the guide tube themselves may be molded of any solid and durable plastics material, for example that known as Delrin, preferably lined or reinforced with chopped glass fibers to increase the strength. Segments constructed of

  This way there is the slight disadvantage of being deprived of

  as conductivity and may be able to develop static electrical charges during weaving. This can be avoided by applying a metal coating, for example vacuum deposition, to the segments and grounding them to the frame of the loom. Alternatively, the segments can be made of metal

  sank. When assembling the guide tubes of the invention

  tion, there is a multiplicity of these segments in

  sufficient (depending on the breadth of the trade and the

  desired) aligned axially on a trestle,

  denying what is thought to be providing a reasonable alignment

  exactly with a difference of + 0.025 to 0.051 mm. Deviations of this order of magnitude can be tolerated without appreciable detrimental effect; nevertheless, we can get a much better operation when the inner walls

  aligned segments 41 are subjected to a rectification.

  For this purpose, an elongate shaft, having a slightly tapered and axially slotted cutting head, having a maximum diameter slightly larger than the diameter of the lower starting bore of the segments, molded raw, passes through the segment alignment, while by rotating at a moderate speed of a few hundred revolutions per minute, for example by means of a hand drill, the head of the rod being coated with any commercial abrasive compound fine grain suspended in a lubricant carrier. rectification provides an alteration

  extremely uniform drilling openings of the segments

  in the alignment of the guide tube and eliminates any internal irregularity. It will be visually verified that the grinding operation is sufficient by placing the eye following the drilling of the alignment and looking

  if the surfaces of the piercing look shiny or he

  cient. As an illustration of an actual assembly of weaving tube with twisted cotton warp yarns with a density of about 30 threads per centimeter of the width of the loom, one could use a

of tube for 20 wires of chalne.

  The size of the diameter of the bore of the guide tube T can significantly affect the operation of the system if it is poorly chosen. For example, with different profile nozzles and collar cross-sectional areas between 8 and 32 mm 2, a 1.9 cm bore diameter works well. If the diameter is reduced to about 1.5 cm, only the larger nozzle (32 mm 2) can project the weft across the full width of a normal loom and the travel time of the weft is increased by one. prohibitively Apparently, the diameter of the hole must be relatively large

  to allow for relatively easy entry and pas-

  wise of the jet of air supplied by the nozzle. Firstly, the diameter of the tube bore in relation to the diameter of the nozzle, its spacing from the inlet of the tube and the angle of the nozzle of the jet must be sufficient for the jet to enter almost completely into the inlet. of the tube. Secondly, the drilling should not be too "tight" with respect to the air column moving through, otherwise the column would encounter excessive resistance when passing through the crowd and "leak" or escape through the slot 49 and by the gap between

  the tube elements. If the nozzle opening is sufficient

  large enough to emit a burst of massive air, the impedance of a "tight" tube can be overcome, but

  resistance is still manifested by seriously delaying

  the very advance of such a massive puff. It is currently unknown until the diameter of the piercing can be increased without approaching an unconfined environment

  for the frame and without losing the advantage of the guide tube

  ge; it may therefore be useful to experiment to establish the effective limits of the variation of the

  diameter of drilling in doubtful cases.

  In the embodiment of the loom according to the invention as shown in the drawings, the nozzle

  weft insertion N is mounted on the frame of bat-

  both in a stationary or fixed position and does not move in synchronism with the compound motion of the weft guide tube. This allows a simplified construction and in this way the efficiency of the tube for

  the insertion of the frame is not appreciably reduced.

  Ciable. During the weft insertion phase, the vertical movement of the tube is substantially zero, and the axis of the insertion nozzle is substantially aligned with the axis of the guide tube during this phase. But, if desired, the insertion nozzle K could also be mounted on the mobile support base 45 of the weft guide tube, so that the axis of the nozzle "would follow" in

  makes the center axis of the guide tube in the cycle of -

  complete work of the trade. We can understand that this

  provision could provide a slight increase

  complement of the overall work rate by triggering the frame insertion phase at a point

  located a little earlier in the cycle.

  (b) The particularities of the

  mechanism for lifting and extracting the weft.

  When the frame guide tube is attached

  on the flap as it is known in the systems of in-

  by the air, its discharge slot is placed at a point of the upper peripheral portion of the annular tube segments, so that the tube path during extraction under the bottom of the shed produces the passive displacement of the weft thread inserted out of the evacuation slot. That is, when the

  guide tube, with its weft thread inserted at its

  inside, out of the crowd its thin ring segments

  individuals are able to slide in the intervals

  between the warp threads, while the weft thread itself, being restricted by the aligned web of threads

  crowd, can not do it and must therefore remain in

  the crowd when the segments of the guide tube

  they rotate and leave. As a result, the position of the evacuation slot was chosen to facilitate passage of the weft thread through it. In the invention, it is possible to use the massive displacement of the weft, if desired, and while the optimal location of the evacuation slot

  49 for this purpose may vary according to any specific

  In general, it has been found that good results are obtained with a location of about 130 to 1400,

  from the plane passing through the axis of the extensions

  ports 43 and counting clockwise a

shows.

  However, in the invention, it is preferred that instead of moving the inserted weft threads

  passive way as above, a mechanism is provided for

  to lift and extract each inner weft yarn

  positively, through the evaluation slot.

  cuation 49 of the alignment of tube segments. In this way one can exercise a more direct control over the

24 78 1 4 4

  position of the weft yarn during threshing and the

  Weeding can be done at a point earlier in the threshing motion than would otherwise be possible. For this purpose, as seen in Figures 1 and 3, a rocking shaft 61 passes through the width of the loom, the front side of the flapper channel 39, in a location with minimal discomfort to

  access to the guide tube from the front of the loom.

  The ends of the sway shaft 61 are capable

  to rotate by turning in supports 63 which make

  connected from the ends of the flapper channel 39, and a plurality of weft lifting fingers 65 are attached to the shaft 61 at appropriate intervals in the width of the shed, including at the points adjacent to the side edges of the shed. Since the relative mass of the weft is in any case extremely small, only a sufficient number of lifting fingers 65 is required to maintain the reasonably right weft during the lifting action (only four for a loom of 101 cm, although of course we can use more and the lifting fingers 65 can be very thin, so as to easily pass through them.

  intervals between the warp threads of the crowd. A le-

  Angle 67 is attached to an outer end

  of the sway shaft and this lever acts by its end.

  mitered in the manner of a follower follower cam cooperating with a ramp 69 established in a stationary part

  71 of the craft frame. The ramp 69 has an indistinct layout

  curve suitable for giving the desired movement to the lifting finger and includes, in the arrangement shown schematically in FIG. 1, an arcuate portion 69a in the shape of a right U and inclined towards the rear, which is

  connects to a front part 69b of generally horizontal shape

  tale and, during the insertion of weft in neutral

  back, the fingers 65 are retracted below the

  yoke 47 of the tube T as seen in dashed lines in FIG. 3; and, when the leaf starts forward toward the threshing position, the follower immediately engages by climbing up the ramp portion 69a to pivot the fingers 65 rapidly upwardly which come into the solid line position of Figure 3; as a result, the weft is lifted in the vertical direction through the discharge slot 49 of the tube segment 41; after which the follower falls to retract the fingers 65 and enters

  in the horizontal ramp portion 69b so as to maintain

  stably hold the fingers 65 in their retracted position during threshing. When the leaf returns to the weft insertion position, the fingers pivot upward, then back down into a retracted position below the guide tube bore, ready

  for inserting the next frame.

  The shape of the fingers may vary, bearing in mind that the fingers must finally leave the crowd between the warp threads in the same way as the segments of the guide tube and must be spaced from the clamping line in the position of the fingers. threshing. Also, the ends of the fingers meeting the wire must be bypassed to positively grasp and hold the wire during their lifting action so as to maintain good control of the wire. Therefore, preferably,

  the rear end of each lifting finger is

  mine by a notch 71, generally V-shaped, for

  define a fork in which the wire will fall naturally

  when the fingers are raised. The remainder of the fingers are arcuate in shape to maintain a gap with the shedding wires when the leaf pivots forward in the threshing position. It is also preferable that the rearwardly cut ends of the lifting fingers are, in their retracted position, a little beyond, in the rearward direction, of the central plane of the guide tube; this places the weft wire closer to the back side of the tube bore.

  guidance than on the front side and promotes regular evacuation

by the exit slot 49.

* Under the impact of the lifting mechanism, the weft yarn is displaced substantially vertically by

  relative to the movement of the guide tube during the

  Therefore, the region of the evacuation slot must be conveniently associated with the high point of the periphery of the tube segments. In this way the extraction of the weft is determined by the positive lifting action of the lifting mechanism, independently of the movement of the guide tube relative to the bottom of the

crowd.

  (c) With regard to the assembly constituting the weft insertion nozzle, it should be emphasized that in order to obtain a more precise and instantaneous control of the flow of air through the nozzle N to advance the weft yarn through the crowd of craft chain, we have

  designed a special set of nozzle and servo control.

  As can be seen in FIG. 4, this nozzle assembly comprises

  It has an outer casing 73 enclosing an interior space, this casing preferably having a circular shape, although its conformation is not critical. One end of the casing, on the left of FIG. 4, is closed by a cover plate 77 fixed by bolts or other fastening means 79, a flexible diaphragm 81 being sealed with its edges between the abutment surfaces. crankcase and plate, squeezing the end of the crankcase. Inside the casing is a two-part core, generally identified by 83, which has the dual function of delimiting, with the inner wall of the casing, an annular storage chamber 75, elongated

  in the axial direction which serves to contain a

  compressed air and which forms between its two parts a divergent annular passage ending in a collar and

an exit opening.

  The two parts of the core include an outer hollow sleeve 85, which has an outer wall 86 of generally cylindrical shape and a conical inner bore 87, and an inner plug 89 in the general shape of a flared trumpet, fitting with spacing in the tapered bore of the sleeve. The hollow sleeve 85 can be fixed by means of a fixed integral flange 91 at its outer end 88 (right) by means of screws or the like 93 at the other end of the housing to complete the closure of the space storage chamber, although the sleeve and the flange can be separate parts connected together. In any case, the sleeve 85 is supported cantilevered inside the housing

  73 by attaching its outer end to the end

  right side of the housing, which also closes this housing (and apart from the orifice of the nozzle) the inner end

  sleeve protrudes freely into the interior of the car-

  ter to the vicinity of its leading end.

  The free end edge of the hollow sleeve 85

  is rounded as we see in 95 to provide an incur-

  smooth and substantially re-entrant between the edge of the

  sin of the conical wall 87 and the outer wall 86 of the sleeve 85. Preferably, the outer wall portion 86 adjacent the free end edge 95 develops with a convex or somewhat bulbous curvature as indicated in 97 to connect more regularly with

  the rounded free end edge 95, while the

  corresponding portion of the inner wall of the housing 73 protrudes radially inward, following a concave curvature as indicated at 99 to form in the intermediate gap an annular mouth 101 which tapers gradually and curving towards

  the inside at the end of the accumulation chamber 75.

  The rounded free end edge 95 of the sleeve provides abutment contact with an inner annular region of the diaphragm 81 and functions as a seat of a

  "valve" which acts, as will be explained, so as to control

  the beginning of pressurized air from the accumulation chamber 75. The inner wall 87 of the core sleeve, after an initial light convex curvature at its end connecting to the free end edge

  rounded 95, has a conical inclined shape

  The trumpet-shaped cap 89 is held evenly and within the conical space thus formed and is held fixed and supported by the inner side of the casing head 77 by means of attachment bolts 103 or the like. central region of the diaphragm being pinched between the flat end face of the plug and the head of the housing. The outer wall 90 of the plug is spaced from the inner conical wall 87 of the sleeve 85 and together they define a convergent feed passage 105 whose radius gradually decreases towards the end 91 of the

  the sleeve is supported and undergoes a slight shrinkage of

  ring near the rounded end edge

95 of the sleeve.

  The top end of the sleeve 89 in the form of

  trumpet ends slightly below the outer end.

  upper portion of the tapered bore 87 of the sleeve 85 and the remainder of the bore 87 constitutes a neck region 107 of the nozzle, connected to the tapered annular passage 105. The neck region 107 is extended by an orifice 108 of the supported end of the sleeve 85 either with a straight cylindrical shape as seen in dashed lines in FIG. 4, or by diverging flaring as indicated in solid lines, depending on the type of nozzle port opening desired, such as

we will explain it.

  Through the interior of the trumpet-shaped stopper 89, and preferably coaxially, there passes a small axial passage 109 which is occupied by a weft feeding tube 111 covering the entire length of the plug 39 and projecting beyond it, or less to the plane of the outer end face 88 of the sleeve 85 and thus to the outer limit of the bore 107 therein. Preferably, the wire feeding tube 111 is integrally constructed of a T-shaped support pin 113, which is incorporated and fixed in the plug, for example with the same bolts 103 which fix the plug 89 itself to the casing head 77. the feed tube and the support spindle fit with telescopic sliding-in the

  axial passage 109 formed in the cap so as to facilitate

  the rapid removal of the tube for cleaning or replacement

  placement. The inner face of the housing head 77 contiguous to the diaphragm 81 in front of the chamber 75 is recessed so as to define a shallow annular recess or manifold 115 opening towards the diaphragm which makes it

  the firm and this annular recess is connected by a con-

  116, shown in cross-line in FIG. 4, through a suitable orifice 117 of the casing head to a source (not shown) of a gaseous control fluid, for example air under pressure, in order to control the movement of the diaphragm. It will be understood that the diaphragm 81 is exposed on its inner face to an annular area of predetermined size, formed by the hollow tubing 115 in the housing head. As the

  diaphragm will flex as necessary to

  To break the forces acting on its two faces, its motion will be determined by the ratio of each of these areas multiplied by the corresponding pressure of the fluid acting on it. The annular areas of the mouth 101 and the tubing 115 may be the same; in this case, as long as the pressure of the control air in the tubing is less than the effective pressure of the air in the accumulation chamber 75, the diaphragm 81 will be displaced

  towards the general axis by moving away from the

  round 95 of the core sleeve and establishing the

  cation between the mouth 101 of the chamber 75 and the ex-

  opening end of the annular passage 105 towards the opening

nozzle orifice 108.

  As the annular passage 105 begins on the radially inner side of the rounded end edge 95 of the sleeve 85 near the chamber mouth 101, it is seen that if the acting diaphragm 81 starts to leave its seat on the end edge rounded and that the pressurized air starts to escape from the accumulation chamber mouth 101, the effective annular surface area of the diaphragm exposed to the pressure of the chamber increases or "grows", which acts to further unbalance the forces acting to bend the diaphragm away

  from its seat with a kind of avalanche effect. By con-

  the diaphragm moves practically instantaneously from its closed position on its seat to the limits of its open position or away from its seat, as permitted by its working characteristics,

  that is to say, by its flexibility, the game of tension, etc.

  Thus, the opening action of the "valve" diaphragm of the nozzle of the invention is extremely fast and in fact it has been found that it was possible to have an operating response for the device of the order of 1 ms, expressing the time required for the pressure in the annular passage 105 to reach substantially the full pressure initially existing in the accumulation chamber 75.

  When it is desired to stop the flow of air

  coming from the accumulation chamber 75, it is again necessary to

  There is sufficient control air pressure on the outer side of the diaphragm within the annular control neck 115 and it will be understood that if the effective inner and outer annular diaphragm surface areas are the same, then need a control pressure exceeding the accumulator chamber pressure to return the diaphragm to its position

  applied against his seat in contact with the edge of ex-

  rounded end 95 of the core sleeve. This is why the ratio of the annular or radial dimension of the control tubing 115 to the annular or radial dimension of

  the mouth 101 of the accumulation chamber is pre-

  substantially greater than 1, for example of the order of 2 or more than 1, to reduce the difference between the opening and closing control pressures. The choice of such high ratios of effective surface area has the additional advantage of being able to deduce

  a control pressure from the same source as the food

  accumulation chamber 75, recalling that the

  control pressure itself does not need to be higher than

  the pressure of the accumulation chamber, because of the "multiplying effect" of the unequal ratio of

  effective rings on opposite sides of the diaphragm.

  As the air, when it escapes from the accumulation chamber 75, must undergo a substantially complete inversion of its flow direction from the chamber mouth 101 to the annular passage 105 when the diaphragm valve opens, it is desirable that

  the mouth 101 and the entrance to the passage 105 are in conformity

  as has already been exposed so as to promote the smooth transition of the air flow and the regular communication between the mouth 101 and the passage 105 without having an acute edge or bend in the walls and thus reducing turbulence and the friction losses of the air flow as well as the abrasive wear on the diaphragm, which must take into operation a fast oscillation between its closed and open positions. For the same reasons, the surface of the casing wall and the head adjacent to the unsupported annular region of the diaphragm must be slightly recessed as indicated at 119 and

  121, so as to provide a free interval for the oscillation

  unimpeded passage of the diaphragm. Otherwise, the duration

  use of the diaphragm would be greatly reduced. As

  suitable for the diaphragm, it will be possible to use

  buna or neoprene rubber, preferably

forced by a canvas.

  The total volume of the passage 105 and the neck 107 is taken as small as possible in harmony with other necessities, since the space located downstream of the diaphragm 81 contains residual air after the closing of the diaphragm and, if is too big, this extends the characteristics

of decline of the nozzle.

  In certain circumstances an extension of the orifice opening 108 in the outer face 88 of the

  sleeve 85 by means of a straight tube 124, cylindrical in shape

  that (seen in dashed line in Figure 4) may be useful. A central region of the end face of the sleeve 88 may be hollowed as seen at 123 to receive an end of such a tube 124, which may be secured in place by means of bolts or other means of attachment 125 and the design of the core sleeve and

  the two-piece support flange can simplify

truction of this set.

  To have a flexible operation, it is advantageous that the dimension and the contour of the neck area of a given nozzle assembly are variable and

  this effect the collar region of the nozzle sleeve is con-

  staggered by an interchangeable insert 127 which

  dapte with close tolerances dansume sleeve 129 of the end of the sleeve. Each inserted piece can be pierced to a given dimension and with a given contour to allow to easily change the characteristics of the nozzle. No special seal or braid is required for tolerances exceeding

not + 0.025 mm.

  The weft insertion nozzle assembly N is mounted on the swing of the loom so that the nozzle can be "triggered" at the proper point of the operating cycle of the leaf. As has been said, the weft insertion nozzle could be mounted to have a

  compound movement similar to that of the guide tube.

  Nevertheless, this coincidence relation is not neces-

  and we have obtained very satisfactory results in

  the fixed nozzle on the leaf, with its axis

  loosely aligned on the axis of the discontinuous guide tube

  when the latter is in a rest position at point

  the extreme movement of the wing.

  The use of the "control" valve to

  phrasing just described eliminates the need

  to have additional control valves in the

  air pressure to the charging chamber

  mulation and the housing wall may include a supply port 131 for connection to one end of a supply conduit 133 (dotted line) which leads to the main source of food, not shown. Next will be described a preferred embodiment of a

  complete circuit of the fluid under pressure.

  Since it is desirable for the nozzle to be mounted in a block on the leaf, the overall size of the shuttle is preferably maintained in relatively modest proportions to avoid interfering with other parts of the craft and in turn this imposes a limitation to the possible capacity of the accumulation chamber 75 inside the nozzle. In the embodiment shown, an acceptable capacity for the accumulation volume was found to be 98.3 cm 3. With this limited capacity the pressure that develops in the passage 105 upon opening of the diaphragm valve may be subject to an advanced initial decline from a maximum value or peak equal to the accumulating pressure.

  in room 75 and this decline in action pressure-

  This may lead to a reduction in the effective thrust force actually exerted on the weft yarn. In the presently preferred practice of the invention, the operating pressure is maintained, during the duration of the pulsation of air emitted by the orifice of the nozzle, as close as possible to its maximum level and this objective can be achieved by increasing the capacity of the accumulation chamber by means of an additional reservoir or accumulator 137, having a substantially larger capacity, which is connected to the supply pressure source as indicated at 136. In this way, load pressure

  applied to the nozzle orifice through the

  105, which would otherwise decline when

  escapes more and more air from the accumulator chamber.

  75, is continuously supplemented by fresh air supplied by the tank 137. This tank must be mounted as close to the nozzle N as is convenient, for example below the same leaf end as on 137 on

  Figure 1 and is connected to the nozzle through a conduit 138.

  If the diaphragm was left open enough

  For a long time, it is obvious that the effect of decline is

  produce, even with the addition of the capacity of the

  see, but with the limited operating times of the nozzle of the invention, it has been found that one can support

  maximum working load pressure by the pulse

  with the addition of a reservoir capacity of around

1311 cm3.

  We have already mentioned the "multiplier effect" produced by choosing a ratio greater than 1 between

  effective work areas on opposite sides of the di-

  This "multiplier effect" can be increased by means of another possible nozzle structure, shown in Figure 5, which is for the most part the same

  to the nozzle of Figure 4 and with the same marks.

  According to this other arrangement, a housing spacer ring 139 is interposed between the head end of the housing wall and the corresponding edges of the head of the housing.

  casing 77, with the diaphragm 81 sandwiched, and a dia-

  Additional pilot diaphragm 81 'is clamped in place on the other side of the ring 139, so that a diaphragm is on each side of the spacer ring 139, with an interposed clearance space 141. The central regions of the two diaphragms 81 and 81 'are fixed with

  the desired spacing relation by means of a disk of

  annex card 143 which is clamped between the flat face of the conical cap 89 and the corresponding air of the head

  carter 77 and which in turn squeezes the central regions

  the diaphragms. Inside the hollow space

  between the two diaphragms and the lateral edges

  mutually facing each other, of the ring and the disk, a freely floating ring 145 has been arranged,

  which has, thanks to a flange 147 projecting laterally

  a larger annular radius and therefore an area

24 78 1 4 4

  effective superficial surface greater on its outer side 149 than on its inner side 151, the annular dimension of the inner side and smaller 151 of the floating ring

  sufficient to cover completely, through

  diaphragm 81, the mouth 101 of the accumulation chamber 75. Thus, a smaller control pressure applied against the outer pilot diaphragm 81 'will serve to control the movement of the valve diaphragm 81 "acting interior contrary to a given pressure of the accumulation chamber and the ratio of the annular differential areas concerned 149, 151 of the floating ring increases the "multiplier effect" exerted on the working diaphragm 81, as will be seen by

the following mathematical analysis.

  According to the previous general description,

  understand that a state of equilibrium will exist on both

  opposite sides of the working diaphragm 81 when the

  of the pressure Pi by the area A, on one surface is equal to the product of the pressure P2 by the area A2 on the other surface and if the surface areas are fixed, this equilibrium condition will switch when the pressure of one side or the other will rise above or fall below its equilibrium value. This relationship can be quantitatively illustrated by admitting a given set of dimensions for effective work areas on opposite sides of the diaphragm, which assembly is used

  in fact in a preferred embodiment of the invention.

  Thus, it will be assumed that the inside diameter of the floating ring 145 is 3.81 cm, the outer diameter of the inner face 151 of the ring is 6 cm, the outer diameter on the pilot face of the ring including the side flange 6.4 cm, the circular contact diameter of the rounded sleeve end edge 95 with the working diaphragm 81 (ie the place of the "seat" of the valve) 4.13 cm and that the pressure (P3) inside the accumulation chamber 75 is 551.5 kPa. The annular area on the pilot side 149 of the ring can be calculated by subtracting the area of the inner opening from the total area of the ring, the pilot side. Since the area is D2, the overall area of the pilot ring is 0.785 x (6.4J or 32.15 cm2, while the area inside the ring is 0.785 x (3.81) 2 or 11.40 cm 2, the difference between the two being 20.75 cm 2 corresponding to the annular area (Ap) of the pilot face

of the ring.

  The total area of the working face of the ring is equal to 0.785 x 62 or 28.26 cm 2, while the area bounded within the end edge 95 of the core sleeve is 0.785 x (4,13) 2 or 13.39 cm2, a difference of 14.87 cm2 for the annular area (As) of the working diaphragm face that supports the accumulation pressure. At equilibrium, the following relation holds: px Ap = Ps x As where Pp is the unknown pilot pressure in tubing 115. Substituting the known values for As, Ap and Ps' p - 551.5 x 14.87 p-20.75 is therefore 395.2 kPa. Therefore, as long as the pilot pressure is 395.2 kPa or more, diaphragm 81 will be

kept in closed position.

  Moreover, as soon as the pilot pressure is allowed to fall below the equilibrium pressure of 395.2 kPa,

  the diaphragm 81 will be displaced by the accumulative pressure

  As soon as this displacement occurs, the inner marginal region of the working diaphragm face, previously protected by the rounded end edge 95 of the sleeve (i.e., the region of the face diaphragm 81 within the

  "valve seat") becomes exposed to the force of pressure.

24781 44

  accumulation rate P, so that the effective area

  receiving Ps on the working side of the diaphragm 81 increases.

  Specifically, the working surface area thus increased is 16.9 cm 2 (substantially the entire area of the inner side 151 of the ring, 28.26 cm 2 minus the area of the inner opening 13.39 cm), which equates to an increase greater than 25% (ie 26.3%)

  of the effective working area of the working side of the di-

  phragms. It is obvious that the product of the pressure of

  cumulation and this increased work area does more

  to balance, and this in a superabundant way, the resistance

  pilot pressure on the opposite diaphragm area

  the opening action of the diaphragm

becomes virtually instantaneous.

  In order to restore the diaphragm to the closed state, a slightly higher pilot pressure must be imposed, which can be calculated in a similar manner. Assuming that the accumulation pressure remains at 551.5 kPa, the new pilot pressure P 'multiplied by the pilot area must exceed the accumulation pressure (close to 555 kPa) multiplied by the increased working area ( 16.9 cm2). Therefore P'p = 255555, or 477 kPa, which is the minimum pilot pressure necessary to return the diaphragm 81 to the closed position on the mouth 101 of the feed chamber 75. The floating ring 145 is made of plastic or the like

  low mass and it is preferably maintained with fleet-

  in its working position in the space 41 between the diaphragms by means of a stabilizing lip 153 which protrudes inside from the inner end of the housing spacer ring 139, the

  size of the space 141 sufficient to allow a

  limited free movement of the floating ring 145 in the direction

  axial axis of the nozzle, while retaining the ring 145 in the

  against possible lateral movement or swaying

  which could have a visible effect on the functioning of

diaphragm 81.

  It will be recalled that the weft feed tube 111 passes through the housing head 77 e of the conically shaped core plug 89 and protrudes beyond the top of the plug by the outer end portion of the bore. 107 in the core sleeve 85 to a point lying at least to the right of the face

  outer 88 of this sleeve. This means that the opening

  The shape of the nozzle orifice 108 necessarily has the shape of a limited ring located between the outer wall of the free end of the feed tube 111 and the inner wall of the bore of the sleeve 107. An important feature of the present invention , common to all the embodiments of its weft insertion nozzle,

  consists in that at the point of minimum diameter of the piercing.

  107, the area of the ring is the minimum area in tDut

  the flow path of air passing through the nozzle. The in-

  minimum area right of the air flow path defines

  the neck of the nozzle and a critical condition of the invention.

  tion is the appearance of a choking effect in this

  collar. From a re-entrant curvature of the

  flow of air in the present nozzle, the ac- chamber. cumulation 75 having the shape of a ring surrounding the piercing 107 and its

  flow passage 105, and given the convergent nature of the passage 105, it follows that the minimum flow area location is at most

  small diameter of the piercing 107 in the embodiments

  represented (the total effective flow area of the annular passage 105 being a function of its overall diameter as well as its annular radius). When using

  other conformations, the same result may not occur.

  follow inherently but the nozzle design

  must in any case satisfy this requirement.

  In addition, when the additional reservoir 137 is used to increase the flow capacity of the accumulation chamber 75 and thus to maintain the complete charge pressure which is supplied to the nozzle orifice, the conduit 138 connecting the outlet of the tank

2478 1 4 4

  additional and the orifice in the housing wall, as well

  that these openings themselves, must have a flow area

  greater than the effective flow area

  neck of the nozzle. Since the duration of the air flow during the weft insertion will ordinarily occupy only a small fraction of the total work cycle of the invention, the flow capacity of the duct

  supply source connecting the pressure source and the chamber

  accumulation and / or the additional tank, where it exists, does not need to fill this same

  provided, of course, that in the time

  pleating available, (between the excitations of the nozzle) the quantity of air supplied by the main source to the reservoir and / or the accumulation chamber is suitable

  to restore them to their initial fill state.

  (d) There may be a self-contained nozzle supplier

  advancement. Naturally, at the beginning of the operation, we will be able to thread by hand, into the feeding tube of

  weft of the insertion nozzle, a pilot element of

  sufficient flexibility to be inserted into the

  feeding tube to pull the end

  te of the weft all the way. Nevertheless, to facilitate the passage in the nozzle, it is preferably provided with a weft threading fastener, which can be seen to the left of the nozzle itself in FIGS. 4 and 5. This fastener is constituted by a small cylindrical housing 161 traversed by an axial feed hole 163 of sufficient diameter to freely pass the weft which must progress in the nozzle and which has a trumpet-shaped inlet opening 165 on one of its end faces. The other end face of the casing adapts with abutment contact against the outer face of the head 77 of the nozzle casing by its feed bore 163 facing the bore 112 of the nozzle feeding tube 111. Around of an intermediate portion of the supply bore 163 is an annular suction chamber 167 having end walls 169, 171 flaring forward

  and communicating with the interior of the food piercing

  163 through an annular opening

  173, directed forwards, in its far end wall

  1. By connecting the suction chamber 167 to a source of air under pressure, a

  ring air flow confined at high speed is pro-

  thrown forward into the feed hole 163, this

  which creates a depression and causes a suction effect-

  in its entrance opening 165. Thus, when the

  free frame is brought to the vicinity of the

  entrance 165, it is sucked into this opening.

  ture and projected forward by the feed tube

111 of the injection nozzle.

  In order to simplify the construction of the

  self-advancement, a cylindrical sleeve 175 pre-

  sensing a convexly flared end face is bored into the housing and a cylindrical plug 177

  of reduced axial dimension, which presents a face of ex-

  concavely flared end, is press-fitted in the socket, leaving an axial clearance to form a chamber 167. An axial opening 179 passes through the plug

  177 and its outer end is flared outward

  to form the trumpet shaped inlet opening 165. A tubular insert 180 fits tightly into the axial opening 179 and occupies about

  the depth of the socket, the insertion piece

  an outer diameter slightly smaller than the diameter

  the inner inside of the flared socket wall for defining, with the open space of the socket, the annular chamber 167 which has the small annular gap 173 at its inner end. A feed passage 181, connected by a conduit 183 to a source of pressurized air (not shown), passes radially through the housing 161 into the annular chamber 167 and, when

  the pressurized air comes from the annular chamber

  In the bore 163, a depression is created in the interior of the tubular insertion piece, so as to suck the wire positively into its inlet opening.

trumpet shaped.

  The alignment of the self-advancing fastener on the nozzle inlet can be facilitated if one forms

  piercing 163 using a tubular insert

  185 which protrudes out of the casing 161 so as to achieve a telescopic interlocking with a part

  outside the feed tube 111 of the nozzle.

  In operation, the supplied air pressure

  to the suction chamber 167 can be maintained from

  continues at a level significantly below the

  calf working pressure of the nozzle, that is to say

from 69 to 138 kPa relative.

  (e) With respect to the pilot pressure control system feeding the insertion nozzle,

  observe that, as indicated above, the pre-

  invention places very high demands on

  operating characteristics of the diaphragm valve,

  in that the valve must have the possibility of

  reproducibly and accurately

  a minimum frequency of 900 cycles per minute, in com-

  boring with an extremely brief actuating time, of the order of 1 ms, and there is provided a special control system for actuating the diaphragm valve observing these conditions. For example, the use of a solenoid valve

* working directly to control pedestrian pressures

  lotes acting to actuate the diaphragm valve of the invention, is out of the question in the present state of

  valve technology. There are control valves

  solenoid actuators, which have a response time of the order of one millisecond, but these valves can pass only a very small amount of fluid in a given time and this low transmission capacity would introduce excessive impedance, so that the

  necessary rapid reaction of the diaphragm valve itself

  even would be impossible. In addition, such, electrovalves

2478 1 44

  fast ones only act in one direction and are characterized by a slow response time,

  on the order of 5 to 6 ms, during their return run.

  The solenoid valves currently available, with sufficient air capacity for the needs

  of the present invention, have a response time of the

  10 me in each of their work directions, which would impose a minimum of 20 ms "delay" for each work cycle and thus, by their nature, prevent the possibility of obtaining response times.

shorter.

  With regard to the electronic embodiment of

  In FIG. 6 there is shown diagrammatically an embodiment of a nozzle control unit according to the invention, based on electrical principles. Two solenoid valves or separate solenoid valves 185a are used,

  b (shown schematically) of transmission capacity

  mission, which are connected to the oppo-

  A common shuttle valve 187, which in turn is connected to its outlet 189 to the pilot port 117

  of the casing head 77 of the weft insertion nozzle.

  During an electrical excitation, each solenoid valve

  moves between a feeding position adapted to

  connecting a suitable source of pressurized air at its outlet and an evacuation or "discharge" position connecting its outlet to the ambient atmosphere, the two valves 185a,

  b being requested in the evacuation position and

  as shown in Figure 6. Outputs 186a, 186b

  respective solenoid valves communicate with the ex-

  opposite ends of the shuttle valve 187. Each side of the shuttle or piston 188 of the valve 187 acts by

  means not shown, for closing the correct end

  respondent of the valve when it is unbalanced at this end. The outlet orifice 189 of the shuttle valve 187 is placed at its midpoint, so that the shuttle or the piston releases the exit orifice in one or other of its extreme end positions. As a result, when the shuttle is in one of the two

  extreme positions, the output of a solenoid valve

  that fully with the shuttle valve output, while the output of the other solenoid valve is closed by the shuttle. In this way the shuttle valve isolates each

solenoid valve on the other.

  The operation of this arrangement is illustrated schematically by the waveforms of FIG. 7. As indicated, each solenoid valve A, B moves between a feed position in which its waveform a, b is high and an evacuation position in which it is low, the transition from these two positions being represented in the form of a line which has an inclination at an angle determined by the response time or delay of the solenoid. The waveform c corresponds to the shuttle valve, the "b" side of the shuttle being closed when the waveform is low and

  the side "a" being closed when the waveform is high.

  The response of the diaphragm valve appears with waveform d, being closed when it is low and open when it is high. The existing output pulsation of the nozzle is represented by the waveform e, the nozzle being "cut off" (without airflow) when the shape

  e is low, and it is "connected" (pulsation of air

  denies) when the form e is high. It is assumed that at the starting point, the diaphragm valve of the nozzle itself is in the closed position or on its seat (and the waveform d is low), while the control solenoid A is in its feeding position (and the shape

  wave a is high) by connecting the source of pressure of

  the "a" side of the shuttle valve, by requesting

  so the shuttle on its side "b" (and the waveform c is low) by closing the output of the solenoid valve "B" and

  establishing communication between the exit of the elec-

  trovalve "A" and the shuttle valve output which applies the control or pilot pressure to the control side of the diaphragm valve actuating the nozzle to maintain

  this closed valve (and the waveform d is low).

  The solenoid valve B is at this moment in its position of

  evacuation or discharge and the waveform b is low).

  A work cycle is triggered in a time t1 indicated by a corresponding line, to open the nozzle diaphragm valve by releasing the control pressure.

  on it and the solenoid valve A is electrically shifted

  in its evacuation position, while the electro-

  valve B remains in its evacuation position. As a result

  this, the shuttle valve remains at its position on the side "b",

  but the control pressure acting on the valve di-

  diaphragm then begins to run out into the atmosphere by evacuating the solenoid valve A to some

  pace determined by the response speed of the electro-

  valve as well as by the inherent impedance, ie

  say the resistance of the passage, etc. in the different connecting ducts. Therefore, the waveform has

  begins to fall at an inclined pace. When the

  The control voltage acting on the diaphragm

  below a certain level calculated at a time t2, the supply pressure in the nozzle accumulation chamber will then exceed the control pressure, forcing the diaphragm immediately to come into position

  opening and the waveform d becomes high. lT'ouver-

  diaphragm valve admits the pressurized air from the accumulator chamber to the nozzle (and the

  waveform e becomes high at time t2).

  The diaphragm valve remains open, with the pulsation of air projecting the weft that is emitted by the

  nozzle, as long as the two solenoid valves A and B are

  vent position (i.e., low) and, in order to return the diaphragm valve to its closed position and to complete the pulsation of the nozzle, the control solenoid valve B is electrically actuated by a time t3 to move from its evacuation position to its feeding position. Thus, the solenoid valve B, seen in waveform b, has its transition from the position

247814 4

  evacuation at the feed position, shown

  by the descending line, whose inclination is again

  calf determined by the response time of the valve and the impedance of the system as before. As the opposite side or "b" of the shuttle valve is then in communication with the atmosphere, because the position

  of the solenoid valve A does not have any

  the movement of the shuttle into the po-

  side "a" (and the c waveform becomes abrupt

  high) and the pressure begins to build up in the control side of the working diaphragm of the insertion nozzle.

  At a certain moment t4, the pressure of com-

  will exceed the existing pressure in the

  cumulation 75; and when this occurs, the diaphragm moves from its open position to its closed position (and the waveform d becomes low). As there is no "avalanche" effect in closing the diaphragm valve, as it occurred during its

  opening, the closing response of the diaphragm valve

  is, therefore, a little slower than his

  abrupt action (as we see on the form of on-

  (d) but this has no appreciable effect on the effectiveness of

  operating site, because a certain decline is inevitable in the evacuation of residual air from inside the passages of the nozzle. Nevertheless, it is desirable that the response to the closure is not excessively long in order to reduce the unnecessary consumption of air

  during each work cycle and the way in which

  nozzle according to the solution of Figure 5 is

  preferable because it allows the diaphragm to close

  sea for a lower order pressure level and

  therefore with a higher response speed.

  when the diaphragm valve closes, the nozzle pulsation is cut off (and the waveform e becomes low at

the moment t 4).

  The signals used to control the actuation of the control solenoid valves A and B of the embodiment of FIG. 6 are electrically deduced, as is also seen in FIG. 6. Each operating cycle of the control system must occur at a specific moment in relation to the work cycle of the profession itself. The command pulse to trigger each control cycle is preferably

  deduced from the drive shaft of the crankshaft

  tier himself. For this purpose, a Hall effect switch 189 is associated with the crank shaft (not shown), this switch being of a powered kind

  by magnetic means and placed at a point close to the

  crankshaft, a small magnetic element being

  on its periphery by the crankshaft itself,

  so that at each rotation of this tree the element ma-

  gnetic crosses the switch and excites it for trans-

put a command signal.

  According to the previous statement of the actuation of the solenoid valves A and B, it will be understood that means

  must be provided to operate separately each

  -trovalve in predetermined chosen moments, which of

  preferably are adjustable relative to each other.

  Also, the moments of generation of the signal of com-

  during the work cycle of the loom must be adjustable so as to adjust the moment of

  of the frame insertion "canon" and to obtain the insertion

  tion of the weft at the optimum point in the work cycle.

  the job. This possibility of adjustment could be obtained mechanically by modifying the location

  of the magnetic switch or actuator of the in-

  Hall effect switch relative to the periphery of the crankshaft, but to perform this of

  convenient way, it would require a mechanical arrangement

  t8t complicated, because especially the crankshaft

  The trade is usually in a different location.

  easily accessible. Moreover, it would be difficult to ob-

  to maintain a high degree of precision in this way,

  that is to say less than 1/3 degree of rotation; therefore, it is much preferable to have an electronic arrangement system for setting the control signal. In this

  Indeed, a pilot clock or device regulating

  191 is connected to the Hall effect switch and constituted by a multiplicity or preferably by three decade counters (not shown separately), each of which is adapted from 0 to 9 in 1 ms intervals, and which includes a dial. associated control for the settings, the counters being coupled together to count continuously from 0 to 999 ms, so as to provide an accuracy of 1 ms. When the initial control signal of the Hall effect switch 189 is received, the clock 191 starts counting and counts for a given number of microseconds, fixed on the control dial of these decade counters and, after having After completing such a count, it issues a command signal. In this way the clock can effectively delay the transmission of the initial command signal

  in increments of 1 ms each up to 999 ms for each

that work cycle of the trade.

  The control signal of the pilot clock 191 is transmitted separately to each of the solenoid valves by means of separate control devices in time,

  with solenoid, 193a, 193b or "sub-clocks" whose structure

  ture and operation are similar to those of hor-

  slot 191, allowing the adjustable delay of the clock control signal in increments of 1 ms up to

  999 ms (or a smaller or larger total if we de-

  to have a more or less coarse degree or no

  setting) and following the delay interval set on the

  dials of the solenoid subclocks, each sub-clock

  will transmit a command pulse at the end of a

  given interval preselected after receiving limpul-

  common control of the main clock. -

  The initial command signal generated by the

  Hall effect interrupter has a very short duration and is not sufficient to maintain the actuation of each of the solenoids during the period of time when the valves

  these must remain in the open position and in

  closing position. Therefore, the control signal

  of each of the delay clocks 193a, 193b is supplied to a device 195a, 195b, acting on the duration of the operating pulse so as to extend it

  or "widen" it for a specified period of time.

  The pulse duration counter is formed by the coupling

  two of the above-mentioned decade counters to provide a capacity of 0 to 99 ms delay in 1 ms increments (although higher accuracy

  is obviously possible with counters with decad sup-

  additional if desired). Also, the power of the

  control signal is usually quite weak, as is true for most logic circuits, and is insufficient to electrically drive the

  solenoid. Therefore, each signal must be amplified

  trusted by an exciter amplifier 197a, 197b which

  switch between a high value and a low value, that is

  ie connected or cut, these states corresponding to the high or low value of the control signal, providing a

  sufficient power to the solenoid valve for its

effective electrical energy.

  It will be understood, by the preceding description,

  that an extremely flexible and precise control system of the weft insertion nozzle is obtained thanks to the arrangements which have been described. In the first place, the operation of the diaphragm valve is independent of the response times of the individual solenoid valves,

  either at actuation or at the cutoff. As the

  separate lenoids determine the application and release

  control pressure, the delay of the solenoid returning to its starting position is of little importance.

  point of view of any control function, whether

  of course, that the delay of the solenoid is not too great for not having been able to return to

2478,144

  starting at the moment corresponding to the next cycle. In

  second place, while the actuations of electro-

  valves are basically produced by rotation

  of the crankshaft of the craft, and are therefore

  directly related to the work cycle of the trade, the actual moment of this operation is adjustable with respect to this rotation, which provides an extreme flexibility to regulate the moment of the insertion of the weft in the trade cycle . Finally, the setting of the instant of actuation of each of the solenoids with respect to

  the other is precisely variable and the duration of exci-

  each solenoid is independently adjustable

with a good degree of precision.

  We will now describe a first mode of

  mechanical application of the device of the invention.

  The control system of the invention must have the ability to operate without failure for several million cycles; and while the electronic system described above is as durable as it can be with electronic components, it could

  it would be better to use a com-

  mechanical control, which tends to be more reliable over long periods of work. This is why an embodiment

  other of the nozzle control system, based on

  mechanical codes, is illustrated in Figures 8 and 9.

  In general, the mechanically operated embodiment includes a pair of valve cylinders which are

  mechanically coupled to each other and to the system of

  trapping of the craft, a cylinder being able to be

  set in its peripheral position with respect to the

  be. Each of the cylinders rotates in a body and includes

  at its periphery, openings for feeding and

  which are located on it, at certain points

  conferred and axially spaced, which during the rotation of the cylinder are respectively

  communication -with feed orifices

  cuation in the body. These holes are in

  communication through a liaison channel

  its sound with a common shuttle valve, similar to that of the electrical embodiment, so as to adjust, during the rotation of the cylinders, the application and relaxation of the pilot pressure to the pilot side or

  controlled from the working diaphragm valve of the tuyè-

frame insertion re.

  More specifically, the mechanical system of Figures 8 and 9 comprises a body block 198, delimited by a dotted line in Figure 8, which is traversed by two large parallel cylindrical openings 199a, 199b (Figure 9). In each of these openings is a hollow air regulating cylinder 201a, 201b, with a clearance of about 0.0076mm, which is sufficiently sealed to support a moderate air pressure. In order to reduce

  wear and avoid the need for bearings, each cylinder

  201a, or 201b is connected in its hollow interior 202a, 202b to a coaxial drive shaft 203a, 203b by means of a floating junction which may take the form of a "hair needle", elongated V-shaped , 205a,

  205b, whose vertex 206a, 206b of the V is set at the end

  free of the drive shaft and of which

  lateral arrangements 207a, 207b of the ends of the V are

  housed in recesses 209a, 209b in the

  inside the cylinder, about the middle of the

  its length. With this flexible coupling, the cylinders

  They will rotate in a block with the trees 203a, 203b, while being free to take a positinn naturally centered in their respective enclosures, because of the flexibility of the hairpin spring as well as

  of their pivotal attachment with him. Other types of

  floating coupling could naturally be

  titués. Each drive shaft 203a, 203b pivots

  in bearings 211a, 211b provided in a wall of ex-

  body end 198 and includes an outer extension

  213a, 213b which carries a corresponding pinion 215a, 215b.

24 78 14 4

  Both gears are engaged to turn to sync.

  the driving force of the two gears

  be provided by a gear directly carried by the

  crankshaft or, if preferred, by the crankshaft

  exit stroke of a driven mechanical transmission

  by a gear mounted on the crank shaft of the

  tier and engaged with a pinion, the drive gear

  being in all cases designated by 216 and rotating

  With a shaft 217. In order to adjust the relative peripheral position of the two cylinders, a pinion 215a is connected to

  its drive shaft extension 213a by an adjustable coupling which can take the form of a pair of discs in contact 219, 220, notched on their adjacent contact faces to obtain their meshing, the disc 219 being bound integrally with the pinion 215a which turns freely on its extension

  213a and the disc 220 being slidably wedged

  at the projecting end of the shaft extension and being urged to bear against the gear disc 219 by means of a compression spring 220 held at its free end by a split ring fastener and a

  Washer 223. Disengaging the key disc 220 from the disc

  219 unlike the force of the compression spring 221, the shaft 213a can rotate independently of its drive gear 215a and thus the rotational position of the cylinder 201a can be shifted as one

  desire in relation to the rotating position of the

  fixed cylinder 201b. The ends of the openings 199a, 199b, in the cylinder body are open to

  put the inside of each cylinder 201a, 201b in

communication with the atmosphere.

  In the body there was a series of steps

  air vents to cooperate with cylinder valves 201a, 201b and, in Figure 8, for clarity of exposure

  and convenience, these passages have been developed and re-

  in the form of external ducts (the body itself

  even in dotted lines only), although in reality these passages will be practiced inside the body The beginning of the passage is an inlet opening, indicated in 225, which is connected to a source of air under pressure (not shown) and also to a supply duct 227 o derive supply orifices 229a, 229b (see Figure 8), namely an orifice for each of the two

  cylinders. At one point of its length axially in re-

  With the associated feed ports 229a, 229b, each of the cylinders 201a, 201b has a peripheral feed recess 231a, 231b which extends over

  the periphery of each cylinder under a given arc

  36000, for example 2700, the arc remaining on the periphery of the cylinder in this place being massive or

  not hollowed out, as in 233a or 233b (we only see this last

  deny on the drawing). When one of the food recesses

  tation 231a, 231b is opposite its feed hole.

  tation, pressurized air is admitted from a supply duct 227 to fill said recess, whereas on the contrary when a part

  wall 233a, 233b is in front of an opening

  feeding party, the latter is blocked for listening.

  air, because of the tight fit of the cylinder in the opening of the body. At the same axial location or, depending on the length, along each cylinder, but

  spaced peripherally from the feed orifices

  229a, 229b, there is an output flow port 235a, 235b (see Fig. 9) which is connected by a flow conduit 236a, 236b to the corresponding side of a shuttle valve, similar to that 187 of the embodiment

  electric and which is designated by 187 ', the valve of

  Here, as in the other embodiment, its outlet 189 'is connected to the pilot or control orifice 117 of the insertion nozzle. Thus, when a cylinder feed recess 231a, 231b, filled with air under pressure, is opposite a flow orifice 235a,

  235b, the air flows into the orifice and passes through the

  flow rate to the shuttle valve 187 ', while a non-recessed peripheral portion 233a, 233b,

  coincides with the flow orifice, this orifice is clogged.

  Between its flow orifice 235a, 235b, and its communication with the shuttle valve, each flow conduit 236a, 236b is derived at 237a, 237b (Figure 8) to form a vent pipe terminating in a

  vent hole 241a, 241b (not visible on the

  9) at the peripheral alignment, but with axial displacement along the length of the cylinder, of the corresponding flow orifice 235a, 235b. At a point along the length of each cylinder and aligned axially on

  the discharge orifice 241a, 241b, an evacuation recess

  tion 243a, 243b is formed on the periphery of each

  lindre and each of these evacuation recesses comprises a peripheral extension complementary to the flow recess 231a, 231b, the remaining periphery being solid or not recessed as indicated in 245a, 245b. That is, the arcuate extent of each discharge recess 243a, 243b is equal to the arcuate extent of the non-recessed area portion 233a, 233b which separates the ends of each flow recess 231a, 231b, while the remaining non-recessed portion 245a, 245b of the cylinder periphery corresponding to each discharge recess is adapted to the peripheral dimension of the flow recess 231a, 231b. A vent 247a, 247b, from the bottom

  of each evacuation recess 243a, 243b, and the

internal grooving 202a, 202b of the associated cylinder

  to communicate the space of the recess with the atmosphere

  phere. Thus, when one of the discharge orifices 241a, 241b is opposite the evacuation recess 243a, 243b, communication is established between the shuttle valve

  187 'and the ambient atmosphere through the ori-

  flow rate 235a, 235b, of the evacuation bypass duct

  237a, 237b, of the discharge orifice 241a, 241b,

  of the evacuation recess 243a, 243b and the vent of

  vacuation 247a, 247b. On the other hand, when the non-recessed peripheral portion 245a, 245b of the cylinder is

  in front of an evacuation cylinder, this orifice is Duchy.

  As described previously, the posi-

  relative starting points of the two rotary cylinder valves

  They will be different, being shown out of phase by 1800 in FIGS. 8 and 9, and can be adjusted as desired. It follows that when each valve

  rotating cylinder, feeding orifices

  bit of a given cylinder will be communicated with each other via the flow recess

  231a, 231b, during a period of each revolution

  determined both by their peripheral spacing

  that and by the peripheral length of the recess of de-

  bit, and as long as this communication exists, the pressure

  is applied to the corresponding side of the turnip valve.

  te 187 ', while the discharge port 241a, 241b will be plugged during this period. The outlet 241a, 241b will also be in communication with the atmosphere (through the discharge recess 243a, 243b, the vent and the cylinder bore) for a period in relation to the peripheral length of the chamber. discharge recess 243a, 243b, and during water the corresponding side of the valve

  Shuttle will be connected to the evacuation. During this

  During this period, the corresponding flow orifice is

  by the massive peripheral surface 233a, 233b,

  complementary to the extent of the discharge recess in their common axial position. While one or the other

  flow orifices 235a, 235b or feed orifices

  229a, 229b, of a given cylinder is clogged, the application of pressure to the corresponding side of the shuttle valve is prevented, even if the other orifice

  is in communication with the feed recess.

  When the feed and flow ports are

  both with the flow recess, the orifice of

  The evacuation of this cylinder must be blocked. The positions

  peripheral cylinders are adjustable

  depending on, so that we can arrange for the stages above to take place in a desired succession. With the structure previously described, each

  cylinder receives the radial thrust of the different

  Air pressure and, over time, the radial force of the pressurized air could cause unacceptable cylinder wear unless countervailing measures are taken. For this purpose, equilibrium feedings 249a, 249b are provided for

  each cylinder on the opposite axial sides of the recess

  the entire axial thickness of these grooves and their peripheral dimensions being

  for each equal to the size of the feed groove

  but with a phase shift of 1800. That is, the

  parts not hollowed out 251a, 251b, between the former

  tremities of each pair of feed balancing grooves

  249a, are exactly opposite diametrically to the non-recessed portion 233a, 233b, between the ends of the corresponding supply recess located therebetween. The supply duct 227 coming from the pressure source comprises extensions 253a, 253b, which form branches at their ends as can be seen

  255a, 255b, to communicate with the respective grooves

  balancing plates 249a, 249b, so as to supply air to said grooves in counterbalance to the pressurized air acting on the feed recess 231a,

  231b, from its supply port.

  There are provided on each cylinder periphery similar equilibrium discharge grooves 257a, 257b which are identical in their arcuate extent and

  the overall axial thickness, but opposed as to the

  peripheral placement on opposite sides of the

  evacuation systems, and

  evacuation 259a, 259b, open into these grooves for

  apply a balancing pressure.

  In addition to the independent adjustment of a cylinder

  compared to the other, the starting position of the whole

  seems cylinders should be also adjustable with respect to the crank shaft of the craft, so as to

24 78 1 4 4

  vary the starting point of the set in the

  cycle of the trade (in a similar way to horlo-

  pilot run 191 of Figure 6). For this purpose, the

  veloppe of the two valve cylinders 201a, 201b, (which

  would naturally be separated instead of being joined together) is supported by a support plate 260, pivotably mounted about the shaft 217 of the drive gear 216 (i.e. the shaft the crankshaft of the loom or an output gear of a transmission which is coupled to it, making one revolution per cycle

  of the craft) and the plate 260 can be adjusted to the

  fixed port 261 by describing an arc with respect to the gear

  training within the limits laid down by a reason-

  arcuate adjuster 261 and a wing nut / screwed on

  a bolt that passes into it. By positioning

  If the support plate 260 is at the start of an operation, the starting position of the fixed cylinder relative to the position of the crankshaft can be adjusted.

  so as to give some flexibility by regulating the

  both the triggering of the "gun" in relation to the cycle

  operation of the profession. In the embodiment

  felt, the adjustment range is less than 100%, but

  as in the trade cycle the interval during the

  which the insertion of frame is possible is only a fraction

  The total cycle does not require a 100% adjustment and a degree of adjustment of about 200 turns is quite practical. If we had

  need more latitude, the training gear

  could be reset in the rotational position.

  As in the electronic control embodiment of FIG. 6, the control functions

  opening and closing of the diaphragm valve

  performed in the mechanical embodiment of

  that by individual means which function separately

  but with an adjustable relation determined in time, one of the cylinders functioning to release

  the control pressure (and open) the diaphragm valve

  me, while the other cylinder works to apply

  the control pressure (and close) this valve. Speci-

  it is the rotation of the first cylinder, or cy-

  leading lindre, arriving in feeding position, with

  both feed and flow ports are

  in its supply recess, which triggers the application of the control pressure to close the

  diaphragm valve - the subsequent rotation to

  supply by the second cylinder, or cylin-

  back, is irrelevant (except to position the second cylinder for possible movement in the

  evacuation position), as well as the rotation of the first

  first cylinder arriving in the evacuation position.

  Conversely, it is the rotation of the second cylinder or rear cylinder coming into the evacuation position, while

  that the first cylinder is already in a position of

  evacuation, which triggers the release of the pressure

  to open the diaphragm valve - the posi-

  the first cylinder in its position of

  vacuation is unimportant except to position it

  for a possible return to its feeding position.

  The shuttle valve moves in passive response position to an applied pressure imbalance

  on its side by the flow conditions of the two cylinders

  and operates to allow one cylinder at a time only to provide control pressure to the diaphragm valve. When the effect of a modification

  the rotational position of a cylinder consists only of

  In order to balance the pressures acting on the opposite sides of the shuttle valve, whether these pressures are high during the feed flow or low during the evacuation, the shuttle valve maintains

its existing position.

  The maximum possible time interval between

  the relaxation and reapplication of the pressure of com-

  apply to the diaphragm valve and consequently the period during which the diaphragm valve remains open (disregarding the delay due to impedance losses)

  occurs when both cylinders coincide exactly-

  in the peripheral position and is equal to the time equivalent of the arcuate length (i.e. in degrees of rotation) of the discharge recess for a given rotational speed of the cylinder. Nevertheless, the coincidence

  exacting of the two cylinders would be equivalent to a single cylinder

  dre and normally we would not use it. The length

  arching of the fixed evacuation recess actually makes

  the maximum duration of the pulse duration and should be chosen with this in mind. By shifting the starting rotational position of one cylinder relative to the other, the time relationship of the two control functions can be modified and the duration of the evacuation period and thus the pulsation of the nozzle can be modified. vary to the maximum possible. The diaphragm valve does not open exactly simultaneously with the arrival of the second cylinder-in the evacuation position, but remains somewhat late because the control pressure must drop to a certain critical level and the speed of the fall The pressure is determined in practice by the impedance of a particular system and must be established experimentally for this system. Once she

  is established, it remains constant in relation to rota-

  of the cylinder and therefore in practice the actual moments of actuation and rest of the nozzle valve are

  fixed by the rotation of the cylinder. After a pre-setting

  the two cylinders turn continuously

  in synchronous relation with the functioning of the

  tier and one relative to the other.

  The response of the mechanical embodiment of FIGS. 8 and 9 is in principle identical to that of the electronic embodiment of FIGS. 6 and 7, except that

  the mechanical embodiment includes an intermediate state

  "rest" or maintenance, represented in dotted lines

  in Figure 7, which does not exist in the embodiment of

  electrical system, in which the cylinder valve actually does not apply or evacuate the pressure, but merely maintains any state that existed before. Specifically, it can be stated that for each cylinder the discharge recess 243a, 243b extends over an arc 900 of rotation and that the feed recess 231a,

  231b is complementary and covers 2700

  tion. It will also be assumed that cylinder A rotates clockwise and cylinder B counter-clockwise, as indicated by the arrows in FIG. 8, and that the feed port of each cylinder is located at 900 in advance of the flow orifice,

  relative to the direction of rotation. We will admit

  nally that the cylinder B has initially rotated 450 in its direction of rotation ahead of the cylinder A and that the starting point corresponds to the moment t1 on the

figure 7.

  For reference, FIG. 10 is a view

  schematic cross-section through the cy-

  the control lugs of FIG. 8 in their starting position, the section line being chosen to show the two feed recesses 231a, 231b, and the recesses

  243a, 243b, recessed despite their displacements

  real axial dimension with respect to each other, the transi-

  between the feed and discharge recesses

  schematically indicated by a massive wall

  this denoted by x, each evacuation recess

  singing in the cylinder bore, while each

  The power supply is closed by the cylinder wall.

  The duct connecting in FIG. 10 each cylinder at its side of the shuttle valve 187 'is indicated both as a supply flow duct 236a, 236b, and a discharge duct 241a, 241b, since the flow ducts and are at the same peripheral location and in communication with each other. As can be seen in FIG. 10, the starting position of the cylinder A is turned by 1350 in the opposite direction of the

  clockwise from the position of the cylinder

  on the left in Figure 8, while the position

  cylinder B is rotated 900 in the reverse direction

  clockwise from the right cylinder in Figure 8. In these positions the cylinder

  B is already in the evacuation state, the

  cuation 241b of B lying half way to the recess

  243b of B (and the waveform b on the

  Figure 7 is low); while the evacuation recess

  243a of cylinder A was just brought against the original

  firing A 241a, so that the cylinder "A" just starts to evacuate (and the waveform has just

  to be low). The shuttle valve is in its po-

  side sition "b" (and the waveform c is low); the control pressure is being released on

  the nozzle and at a certain moment t2, the pressure of com-

  the drum falls low enough that the diaphragm valve

  I come suddenly to the opening (the waveform d being high at time t2) and the nozzle pulsation starts (the waveform e being high). These conditions are valid for the following 450 rotation up to

  moment t3, at which moment the cylinder B has turned

  the evacuation recess 243b just beyond the o-

  vent 241b and is in the state of supply.

  with its feed and flow ports 229b, 236b in communication with the feed recess

  231b of B. As a result, at time t3 the pressure is

  plunged to the 'tb' side of the shuttle valve 187 'moving

  placing it in its "a" side position. So, the

  waveform b becomes high, as does the form of on-

  Dec. This same rotation of 450 for the cylinder A nten-

  there is no change in the evacuation state of the

  linder A (and waveform a remains low). The applica-

  tion of the pressure by the cylinder B to the valve of

  vet 187 'is transmitted to the nozzle control port and pressure begins to be established on the nozzle diaphragm valve. At a certain time t4, the control pressure overcomes the pressure of the nozzle and the diaphragm valve closes (the waveform

  being low). Closing the diaphragm valve

  terrompt the flow of air in the nozzle and the pulsa-

  nozzle formation begins to decline (and the waveform

e begins to be low).

  After rotation 900, the cylinder B remains in the supply state (and the waveform b continues

  to be high) and the shuttle valve and the dia-

  phrasing are maintained as before (and the waveform c remains high, while the waveform d remains

  low); while cylinder A has advanced from the state of

  cuation in the feed state (and the waveform a becomes high), which however has no effect on the

  because cylinder B is already in the state of a-

  Power supply. At 1350 rotation, the system remains stable in all respects, which continues on 900 more rotation or up to a total of 2250 rotation and at this point

  the supply port of the cylinder B comes to be

  by the non-recessed portion 233b of the feed recess

  B, which maintains the existing state of pressure on the shuttle valve and on the diaphragm valve. The

  waveform b falls into its intermediate hold state

  indicated in dashed line in Figure 7. The cylinder

  A remains in the feeding state during this time and

  450 rotation speed again until a total of 2700 rotation, and at this point the cylinder A comes to the holding state (and the waveform has dropped in its position

  dotted intermediate) while cylinder B resists

  in the holding position. When point 3150 is

  reached, the cylinder B has its exhaust port coln-

  cidant with its evacuation recess and begins to eva-

  cuer (the waveform b becoming low). The pressure being

  kept in cylinder A (because of its state of

  hold) the shuttle valve in its position of

  side "b" (and the c waveform becomes low) which con-

  nue to maintain the control pressure on the diaphragm valve (and the waveform d remains low). The final 450 rotation returns the system to the starting point of the moment t1, and at this point the cylinder A arrives at

  the evacuation state and a new cycle begins.

  The magnitude of the phase shift of the two cylinders that can be adjusted may differ from the 450 admitted

  above, regardless of the pulse length de-

  sirable and the frequency of the trade cycle per unit of time. The duration of the pulsation depends on the time interval during which the two cylinders work on evacuation and can vary by changing the relative times at which the last cylinder becomes low and the

first cylinder becomes high.

  Another way of thinking about

  mechanical application according to the invention. In the mechanical embodiment which operates according to FIGS. 8 to 10, it is necessary to interpose a shuttle valve between the flow orifices of the two cylinders in order to prevent

  transverse communication between these

  bit, which would allow the pressurized fluid applied

  by the feed recess of a cylinder to be di-

  taken to the atmosphere by the recess of

  evacuation of the other cylinder, which would result in

  control in the operation of the di-

  phragms. By changing the arrangement of the cylinders it is

  possible to eliminate the shuttle valve and in the figures

  FIGS. 11 to 13 show an assembly operating in this way. Apart from the elimination of the shuttle valve 187 ', the body of the device and the drive means, in this embodiment, are the same as

  for the previous one and, for the sake of clarity, in the view

  schematic view of Figure 11, we omitted

  swimming, trees, etc. and the body is represented only by its dashed outline 198 ', while the various air passages, which would actually consist of holes in the body, are developed in the form of independent conduits, for the understanding. The body 198 'contains apertures 199'a, 199'b, into which the cylinders 201'a, 201'b fit. The cylinders themselves are identical except that they have opposite directions of rotation and have a reverse arrangement. At the opposite ends of each cylinder there are massive parts

  204a, 204b and 206a, 206b, forming collars, which allows

  attempt to adapt with pressure maintenance when the cylinders are mounted in the body 198 'and, apart from

  certain areas not hollowed out or "islands", which will be

  the periphery of the cylinder between these necklaces of ex-

  tremity 204a, 204b, and 206a, 206b is recessed or di-

  reduced meter as seen in 231'a, 231'b, to form a continuous annular chamber. A supply duct 227 '(see FIG. 11) connected to a power supply

  pressure air (not shown) has

  to form orifices or supply channels 229'a, 229'b, so that the feed chambers

  are continuously supplied with

premium.

  At an intermediate point of the length of each cylinder, the annular supply recess is interrupted by a non-recessed solid diameter arched region of the periphery of the cylinder or island 242a, 242b,

  and a terminal part of each of these islands has its

  inside indented as we see in 243'a, 243'b for

  sea an evacuation recess that communicates through a vent

  247'a, 247'b (see FIG. 12) with the internal drilling

  202'a, 202'b and therefore with the surrounding atmosphere

  nante. A flow orifice 235'a, 235'b is disposed in

  corresponding points in the periphery of the

  Cylinder stops 199'a, 199'b and at an axial location included within the axial limitation of the island 242a, 242b, so that as each cylinder rotates, the associated flow port can be ported. selectively with a feed recess or with an evacuation recess (in which case the communication with the feed recess is also pocketed by the marginal edges of the island around

  evacuation cavity and serving as a seal between the

  evacuation drain and the supply recess) or can be plugged by a itself. The two flow orifices 235'a, 235'b are connected by a conduit

  common flow 236, which is connected to the control port

  of the nozzle through the conduit 189 ".

  The rotating cylinders of the provision

  possible alternative will also be subject to

  which could produce, over time, a usu-

  excessive, and in this embodiment it is also

  advantageously to provide a means of balancing these radial forces, which is similar to that already described

  for the previous embodiment. For this purpose, each

  that island 242a, 242b and discharge recess 243a, 243b is doubled, with a phase shift of 180, by a pair of balance islands 249'a, 249'b and recesses 251'a, 251'b with a pair framed in the axial direction the island

  principal and which together cover the

  pheric and axial, respectively of each principal

* blade and each evacuation recess. The recesses 251 'a, 251' b communicate with the atmosphere as seen in 252a, 252b. Each balance island group 249'a, 249b and recesses 251 'a, 251'b has an associated balancing hole 255'a, 255'b, these orifices being connected to the same flow conduit 189 " that the flow orifices 235'a, 235'b.So, whatever the pressure

  applied to each island or evacuation of each

  that cylinder, this one is exactly balanced by a

  equal, but opposite, pressure applied to the islands of equi-

  libration and recesses for this purpose.

  The operation of the other mode of

  possible mechanical arrangement closely resembles that of the main embodiment and a waveform diagram illustrating the cyclic operation of the other possible embodiment is provided by FIG. 13 (the c and e waveforms being absent, because the valve

  Shuttle is omitted and the throttle nozzle does not change.

  not). If both cylinders are in the evacuation state

  (that is, if both waveforms a and b are low

  ss) or if one cylinder is in the evacuation state and the other cylinder in the holding or blocking state (ie if one or the other of the waveforms at

  and b is low and the other is in an intermediate position

  diary) then the diaphragm valve actuating the nozzle will be open (the waveform d being high) and the nozzle will emit a pulsation. Conversely, if both cylinders are in the state of being (ie if both

  waveforms a and b are high) whereas their

  flow rates communicate with a recess of

  or one cylinder is in the supply state and the other is in the hold state

  blocking (that is to say that one or the other of the

  wave a and b is high and the other is in the intermediate position), control pressure will be applied

  by the control conduit 189 'on the diaphragm valve

  me to close this valve (the waveform d being low-

  se) and ends the excitation pulse of the nozzle.

  As the relative positions of the evacuation recesses and blocking islands are reversed in the two cylinders,

  the island leading into a cylinder while the recess of

  evacuation is in advance in the other cylinder, a cylinder

  dre will be in the state of blocking or holding and the other, in the state of evacuation, and by varying the angular relationship of the two cylinders, that is to say the distance measured according to the arc shown by "y" in Fig. 13 the length of time or duration during which the diaphragm is free of control pressure and thus the length of the pulsation of the nozzle can be adjusted. The maximum duration of the pulsation occurs when the cylinder A moves and arrives in the holding position at the same time as the cylinder B moves and arrives in the evacuation position; while the minimum pulse duration occurs when both

  cylinders move simultaneously to come into

  evacuation. In Figure 13, the waveforms

  a and b have been represented in corresponding positions

  at the maximum relative spacing of the two cylinders, that is to say, the maximum possible length of "y", the

  nozzle remaining open to a total of 900, for simplicity

  proud. In practice, the interval between the opening and closing of the diaphragm valve would normally be much smaller and in any case the arcuate extent of the islands and recesses can be varied to suit the circumstances. (f) Regarding the dosage of the frame and its storage, we can say the following, in relation with

  a preferred embodiment of the rotating drum.

  An important object of the invention is, as already stated, to reduce the amount of waste that can be obtained by fabricating fabrics using the system of the invention. If one tried to adjust the length of the weft thread inserted into the chain directly by the time-controlled actuation of the weft flow clamp placed upstream of the insertion nozzle,

  there would be considerable practical difficulties.

  In the first place, even pliers operated by

  which are designed to operate accurately, are not reproducibly accurate to less than the impact of the triggering of the insertion nozzle, one can easily have variations of the order of a few ms, which produce

  appreciable differences in the length of the frame

  bitée. For example, with frame arrival times of the order of 30 ms, the frame travels at an average speed of about 5 cm / ms, so that the variation in the duration of actuation of the clamp, on the order of 3 ms, would produce a difference of 12.7 to 15.2 cm in length

the debited frame.

  In addition, there is an inherent dispersion of the frame rate at the speeds in question for which the throughput is from storage coils. By

  for example, when wire wound is pulled quickly to

  from the storage position with high speeds, appreciable forces of inertia develop and therefore, when reaching a limit, it is subjected to an appreciable overshoot, that is to say at a jerk, the effect of which is variable in itself, which makes it impossible to accurately fix the length of the wire that advances from the wound feed beyond a given point, within a fixed time interval . Also, the thread that unfolds, forms a "balloon"

  in its journey from food and the resistance

  this trail offered by the environment unlike this balloon is also variable and affects the speed

instantaneous flow of the wire.

  To avoid these practical difficulties, we have

  envisaged in the invention another solution for controlling

  2) der the supply of the frame, based on two principles

  basic simple. In the first place, as the duration of each

  that work cycle of the trade is constant for a given operating speed, of 150 ms for example for a working speed of the trade of 400 picks per minute, the exact length of frame required per trade cycle is fixed and the device of feeding of

  frame can be adjusted to exactly

  shot of a roll or feed package, the exact amount of weft during each work cycle and

  provide it to a storage device. For example

  ple with a supplier of cylindrical wire, its diameter

  is naturally known and simple mathematical operations

  can be used to calculate the size of the rota-

  per cycle required to provide a frame length

  equal to the width of the craft. Therefore, as the first

  principle, during each work cycle of the trade, a storage device having a flow point is provided with a frame length equal to that

  consumed during the cycle, that is to say equal to the

profession.

  Secondly, it is postulated that the collected weft yarn is extracted entirely from the storage device during each work cycle.

  and is stretched as straight as possible,

  firing from the fixed point of flow, through the nozzle of

  in the crowd, without any rounding,

  key, slack, etc. If the exact amount of frame that is needed for each cycle is made available during each cycle and if this amount of frame is actually taken in full on the storage device during each cycle, so obviously the

  amount of frame extracted must be correct.

  In applying these principles, the system of

  This intervention includes a frame and stock dosing unit

  ge shown in detail in FIGS.

  unit includes a drum 300 of generally cylindrical shape

  that has a smooth peripheral surface and

  is mounted on the free end of a shaft 302 carrying

  with a driven gear 304 which is ac-

  positively coupled, as indicated by the dashed line 306, to the drive shaft crankshaft C of the loom, so as to be driven continuously in

  rotation synchronism with this crankshaft.

  The coupling may take the form of pulleys

  which are connected by a drive belt, or it may be a transmission

  variable speed so that you can adjust the

  drum rotation by trade cycle and

  as a result the linear distance of the path of a given point

  born from the periphery of the drum by revolution of the crankshaft. The drum is arranged in the vicinity of a

  side of the loom, its axis of rotation being directed,

  in general, parallel to the axes of the leaf and the frame guide tube (not shown in Figures 14 and 15). At its inner end facing towards

  crowd, the drum preferably has a conical nose

  that 308 to allow to extract the wire from it the

  along its axis, without touching an acute edge.

  The outer portion 310 of the drum serves as

  frame metering means which operates in such a way as to

  milking, at a determined rate, a correctly measured weft length from the weft feed package P which is supported at a convenient location on the craft frame and to maintain a positive frictional engagement with the weft, way to get

  a controlled advance and at the same time

  the weft that is being fed against a sliding

  is lying. The dosage portion of the unit may take a number of forms, but preferably it includes a nip roll 312 which is applied to clamp the wire against a location of the periphery of the outer portion of the drum. The amount of frame that can be found on

  the outer metering portion of the drum is not critical.

  tick and can vary widely. We get in practice-

  good results by applying two or more turns (or turns) of the weft on this outer part 310

  keeping them apart, that is to say with a

  the number of turns and the size of the spacing, that is to say the pitch of the helix, being

  determined by several guide eyelets or entail-

  spaced apart 314, the innermost of which is a closed guide eyelet 316 which grips the wire positively as a support in the axial direction and which constitutes

  a fixed frame rate point delimiting the part

  See. Preferably, the pinch roll is in

  tact with several turns of the weft thread, which ensures a good control of the weft during its supply

  party and avoids the possibility of forma-

  knots, but we could have or substitute

  means to keep the frame under control in

this region.

2478,144

  According to another possible solution, if the

  is wrapped around the outer portion 310 of the drum with a sufficient number of turns or turns

  large enough to create sufficient frictional contact

  to the positive entrainment of the weft by the drum,

  the pinch roller 312 could be removed. nevertheless

  least, the presence of the pinch roll is preferably

  because it ensures that the frame moves in a straight line

  on the periphery of the drum and is not free to

  slipping. As a possible alternative, we could use

  a pair of feed rollers (not shown).

  tees), which would engage the weft in their nip, to control the flow of the weft towards the guide eyelet

  316, but this would imply additional complications

  for the synchronization of the advance, during

  the rotation of these feed rollers on the rota-

drum.

  The free outer end portion 320 of the

  drum 300 functions as a means of storing

  me that serves to collect on its surface the length of

  frame provided by the metering portion 310 via

  of the closed frame guide 316, which constitutes the transition between the two parts and sets the outer limit of the drum storage portion 320 as well.

  although the inner limit of the dosing portion 31 0.

  In order to ensure that the turns formed by the

  310 are provided by the working guide.

  closed 316 with the suitable succession on the storage portion 320, a shoulder or ramp 322, slightly inclined downwardly and inwardly, is provided at the drum periphery, approximately to the alignment

  on the closed guide 316. When a turn is

  denies the storage part, it comes into contact with the ramp 322 and will be bent and seized internally by it, leaving the ramp free to receive the

  next turn to collect. Otherwise, a subsequent turn

  quente could fall on it or even place itself at the in-

  inside an anterior turn and produce knots.

  A preliminary guide 315 and a tensioner 313 (see FIG.

  15) precede the pinch roller 312 for preventing

  the grid to make lateral meanders while

  from the supply winding P.

  Leaving the inner end of the

  300, the weft passes through a guide 324 disposed coaxially with the axis of the drum, the guide preferably having the shape of a closed eye or hole disposed in the center of a plate 326 mounted vertically. During the extraction of the weft turns of the storage portion 320 during the insertion of the weft, a balloon develops in the path of

  frame as indicated in 328 upstream of this eye of guiding

  which defines the downstream limit of the wire balloon and the plate 326 helps to prevent the balloon from invading the balloon.

  rest of the frame and to create entelements.

  Inside this balloon guide is a dart clip.

  positively actuated weft bit 330, which may in practice be disposed on the leaf just upstream of the insertion nozzle (not visible in FIGS. 14 and 15). At the speeds of work envisaged here, it is

  necessary to have a quick-response forceps, and to pre-

  it has the shape of a skate 322 animated by a movement

  back and forth by means of a solenoid 334, and ve-

  making contact with a fixed anvil 336. The solenoid

  334 is actuated by the crankshaft of the loom and by means of a Hall effect switch or cam-operated microswitch or the like (not shown), which is set to actuate a relay and

  close the clamp when needed, any delay in

  the solenoid being allowed to regulate the moment of

  opening of the clamp, which is not critical.

  When the frame passes through the frame guide

  closed 316 near the rotating surface of the

  In the case of a storage drum 320, a stream of air is created by the so-called Coanda effect, which causes the weft to follow the surface of the drum in motion. But the strength of the Coanda effect is not sufficient to ensure that after the stored length of weft has been extracted from the storage portion 320, a new weft length that will arrive will wrap around the drum again and, thus, to apply an additional winding force which completes the Coanda effect, an additional circular air flow is provided. In order to generate this additional flow,

  a ring 340 surrounds with little play the part of stock

  age of the drum, the ring being hollow and generally toroldale; this ring is essentially constituted by a hollow core 342 functioning as a tubing and

  connected to a source of fluid under pressure, not

  ted. This fluid, for all the practical needs, is air and consequently, for the convenience, one will refer

  to this ring under the name of air ring. The wall

  the inner air ring is perforated by a series of circumferentially spaced slots 344 which communicate with the hollow core

  342 and which provide from it the fluid

  m in the annular gap 346 between the inside of

  the ring and the outside of the drum storage part.

  The slots 344 are inclined in radial directions from their end of the tubing inward in the direction of rotation of the drum and a circular or vortex flow of air, indicated by the succession of arrows. 348 is generated around the storage portion of the drum by soliciting the wire

  frame to be applied against the periphery of this

  to be collected in the form of a winding, that

  being thus kept tight to prevent it from

  der. Moreover, any "soft" that could develop in

  the weft, due to the relative movement between the nozzle of

  sertion and the fixed drum, is automatically absorbed

  by the annular flow of air and rewound on the drum.

bour.

24 78 144

  In operation, the wire coming from the winding

  The feed is first fed by hand through the preliminary guide, below the nip roll and around the dosing portion, with the appropriate number of turns, through the fixed weft guide.

  (and any additional intermediate guides), the

  the air ring, the balloon guide, the

  tensioner, the flow clamp and finally the nozzle

  injection. Then the craft can work in the usual way. Once the loom works, the drum rotates continuously, the air continuously feeding the ring and after each length

  the storage part was extracted during the

  tion, a new frame length is produced by

  the dosing part and supplied to the storage part.

  The combined force of the annular air flow and the Coanda effect can vary and is sufficient to produce the winding on the surface of the drum, whenever its voltage falls below a certain level in the range of 1 at about 5 grams, and this force is applied equally to the downstream side and the upstream side of the wire. This means that the bias is caused by the winding, not only of a thread recently dosed on the surface of the drum, but also by any excess weft downstream of the storage drum portion 320 on the drum surface, which is useful to prevent the threads from squirming. However, this effect can also pull the yarn backwards and an important function of the weft feeder 330 is to prevent the weft from being removed from the shed after it has been inserted and at the same time storing the weft for the insertion

  next is triggered. It is clear that the voltage

  in the weft by the excitation of the nozzle of

  the force of the air ring is greatly exceeded, but there is a moment, towards the end of the insertion phase, for which this tension has dissipated and the inertia of the inserted weft falls below the urging force of the air ring. If the weft remains free at this time, it would be extracted out of the crowd when the urging force of the air ring would occur as a result, the re-energizing moment of the clamp should be set to occur.

re before this happens.

  If it is remembered that the pressure trace of the excitation pulse of the insertion nozzle has a configuration of generally trapezoidal shape, it will be understood that it is necessary that the clamp to be actuated does not close during more than a few ms, ie 2 to 5 ms, after the end of the excitation pulse and, preferably, just a little before

  the pulse has not completely faded. In addition

  their, it is absolutely necessary to avoid the actuation of the clamp while the nozzle pressure remains at appreciable levels. If the weft is retained by force, by the clamp or otherwise, while being strongly stressed by the blowing of the insertion nozzle, the weft tends

  to disintegrate because of the vertical forces

she suffers.

  The release of the frame by the clamp for

  the next insertion step must precede the exci-

  tation of the insertion nozzle. With regard to the

  As soon as the re-excitation of the clamp with respect to the end of the insertion stage, when the stored weft windings escape from the surface of the storage drum by the nozzle, the final turns tend to exceed the drum due to of inertia, as has already been said, and it has been found that there is an initial rise in the voltage in the moving frame, which is detected by the voltage detector 338, which may be due to

  this jerk. Therefore, it would be better to

  delay the operation of the clamp a few ms, or 2 to 5 ms, after the increase in tension, at the beginning, to let calm this coupoup and for the frame to take its desired straight orientation before being

  entry. When the weft is stretched backwards

  than at the fixed frame guide, a crisp ridge appears

  the frame voltage in the detector and this indica-

  tion can be used to establish the correct relationship over time for the operation of the clamp. By determining the supplied frame length

  by the storage drum part, it is necessary to

  the drum operates continuously during the entire trade cycle, so that an additional frame is added to the storage drum portion during the same period of time the weft length already collected is extracted by the

  insertion nozzle. Nevertheless, following the two prin-

  As explained above, the output flow system adjusts itself in the sense that with the correct amount of weft that is transferred to the portion of the storage drum 320 during each cycle and if the length is retracted fully up to the guide

  closed frame, it becomes unimportant to know

  is the frame length collected during the storage phase and how much is added to it during the frame insertion stage. This consideration

  deserves to allow without difficulty a tolerance of

  ms because of the relatively slow speed of cir-

  weft control during dosing and storage,

  compared to its fast rate during insertion.

  For example, with a 122 cm loom and an operating cycle time of 150 ms, the straight line speed of the frame being metered and stored is only about 0.76 cm / ms, so that a variation of + 4 ms only creates a difference of about 2.5 cm in length

of the frame.

  Because of the extremely rapid advance of

  frame during the extraction of the storage part

  As the air is projected through the nozzle, it may be desirable to apply to the weft a retarding frce exceeding the slight voltage of the detector 338 in the region.

  between the balloon guide 324 and the locking clip

  output bit 330 and it is possible to use for this purpose a dis-

  positive conventional tensioner to increase the voltage of the detector. However, it is well known that it is difficult to precisely control conventional tensioning devices and it is best to avoid them if possible. As another possible solution, the advance of the frame from

  of the storage part 320 can be delayed by increasing

  the distance between the inner end of the drum and

  bour 300 and the balloon guide 324. This increases in

  the size of the balloon 328 and therefore the resistance

  applied to the length of the balloon of the weft

air and forces of inertia.

  It is also possible to envisage another embodiment with a fixed drum, as a solution that differs from the rotary drum unit described above. In this case, the metering and storing of the weft can be accomplished by means of a stationary drum unit, similar in principle to the yarn supplier disclosed in U.S. No. 3,776,480 to which

  refer to have a more complete understanding.

  In a general manner, the other possible embodiment that can be seen in FIGS. 16 and 17, comprises a fixed support 360, which can be constituted by a starting console

  the building of the craft, and in this support rests, by a

  The transmission shaft 364 is attached to the shaft between these bearings to receive a timing belt 366 driven by the crankshaft shaft of the loom (not shown).

  presented), so as to provide a mechanistic

  that positive between the crankshaft shaft and the turn shaft

  ing. The free end of the shaft protrudes

  overhang towards the craft, as seen in 368, inside the support 360 to carry by its end

  protruding a hollow drum 370, of generally cylindrical shape

  drique, through interposed bearings 372 which allow independent relative rotation between them. The drum is formed by a multiplicity of segments

  374 clamped between end walls 376, 377 and

  riphériquement spaced from each other, so as to define a multiplicity (for example in the number of 6 or 8) of axial slots 380 (see Figure 17) uniformly distributed to the periphery of the drum and a corresponding multiplicity of bars 382, directed in the axial direction, which are placed freely in these slots. The bars are each integrally connected, towards the center of their inner sides, to a common support spider 384 which fits into the interior of the hollow drum, but which is not connected to the drum segments. The cross

  pivots, via a landing 385, on a man-

386 keyed at 388 at the end of the shaft 368, the periphery of the sleeve being both eccentric, as indicated in 390, and slightly biased or inclined by

  relative to the axis of the tree, as indicated in 392, of

  to place the axial bars obliquely in their

  slots. The drum is held against a rotation

  by one or more stationary magnets 394 each of which is supported near the periphery of the drum by the end of an arm 396 projecting from the fixed support and attracts an associated magnet 398 embedded in one of the segments of the drum. So when the tree

  while the drum / bar assembly remains stationary

  384 flutters around shaft 368 by applying a "nutation" or "pendulum" motion to the aligned assembly of axial bars 382 relative to

  on the periphery of the drum, which serves to advance

  the turns of a wire surrounding the drum.

  The outer end of the shaft 362 is hollow, as seen in 397, so as to define an axial weft thread passage for the weft yarn which arrives from

  its supply winding (not visible in the figures

  16 and 17) and communicates with the channel 399 of a radially and axially projecting hollow winding tube 400 which has a free end 402 opening and terminating in the vicinity of the outer end of the bar alignment. 382. For the purposes of the present invention, an arm 404 extends from the end of the

  winding tube 400 for carrying a grommet 406 of

  closed weft at a point along the length of the drum and roughly coinciding with the middle

axial bars.

  The inner end wall 376 of the drum is surrounded by an air ring 407 similar in structure and operation to the air ring of the rotating drum embodiment and beyond

  of the air ring, the end wall

  long axial tapered 408 to facilitate the pas-

  regular sage of the frame. A ball guide eyelet

  410, similar to that of the previous embodiment

  tooth, is disposed coaxially and spaced from the inner end of the drum to guide the weft

towards the nozzle.

  The outer axial part of the drum unit

  bour and bars, between the end of the winding tube

  402 and the closed guide eyelet 406, operates in ser-

  vice as the dosage part of the unit, receiving the

  frame provided by the winding of food

  weft through the winding tube

  400, this tube turning to the correct number of revolutions per cycle

  key of trade in relation to the diameter of the whole drum-bars to wind on the drum the length

  * desired frame for this cycle. The inner axial part

  re drum between the closed frame guide eyelet

  406 and the air ring 407 functions as part of

  ckage to maintain the frame length which is extracted

  by the insertion nozzle, the closed guide eyelet 406 forming the connection between the metering and storage parts and limiting the axial course of the windings stored during the insertion. The weft guide eyelet 406 rotates in a block with the winding tube and in fact progressively transfers the turns or turns

  of the weft, previously applied to the part of

  wise, to the storage part, while the tube of

  rollover introduces new weft towers on the

  dosage. The "nutation" movement of all the bars relative to the periphery of the drum serves to space the windings by approximately 0.16 to 0.24 cm.

  each other following the inclination and gradually

  windings in the axial direction both along the metering and storage portions and to maintain these separate helically wound coils. The total number of weft turns on both parts is sufficient to exert sufficient frictional force on the weft

  in these windings, so as to keep them in

  both sliding around the drum following the tube

  rotating winding and consequently a new work

  is drawn from the power supply to go through the channel

  399 of the winding tube when the latter turns

  rotation of the drum in relation determined in time with the rotation of the crank shaft of the craft. As

  the shaft 362 rotates at high speed during operation

  for example at several thousand revolutions per minute,

  balancing must be neat to get a function

  vibration-free and masses 412, 414 can

  may be planned for this balancing at points

propriate.

  The air ring 407 operates in the same manner as before to retain the weft windings on the drum storage portion and to eliminate any play or slack that may be formed between the nozzle

  injection and the closed frame guide eyelet 406.

  (g) With respect to the reception of the weft and the arrival detection, to ensure that the leading end of the weft, after insertion through the crowd, is engaged and maintained during threshing in the weft, a weft receiving hollow vacuum tube, generally designated V, is mounted on the end of the leaf opposite to the insertion nozzle, the tube being open at one end in the vicinity of this side from the crowd and facing him and connected to

  its other end to a source of depression (not

  presented) which maintains a depression of about 50 cm of water in the tube. In Fig. 18, a preferred embodiment of a vacuum tube has been shown and in this embodiment the end of the adjacent tube

  the crowd is lengthened or flattened at 440 (see also

  FIGS. 2A and 2B) in a sensitive direction

  vertically, parallel to the plane of the comb R, for

  focus the suction force. In order to reduce the

  that the leading weft end does not meet this slot-like aperture, having a width of about 0.95 cm, flanges 442, 444,

  protrude laterally, leave on both sides of the

  in order to increase the "target area" of the

  Verture. These flanges have the effect of temporarily stopping

  movement of the end of the frame if it came

  to miss its entry into the opening of the tube and this suffices

  made sure that the suction in the end of the tube was

pull the frame end.

  With regard to the arrival of the frame to the

  right of the receiving tube, it is advantageous that it be detected positively. In case the end of the frame does not completely cross the crowd, this

  that can happen when this end gets confused

  the, it would follow a defect in the manufactured fabric which can become permanent if one continues the weaving. AT

  this effect, it is possible to provide a photo-detection unit

  on the receiving side of the crowd, this being

  preferably a modified form of receiver tube

  shown in Figure 19. With this embodiment,

  the tube itself is circular at 440 'and is provided with telescoping on its open end, a

  larger necklace 446, generally oval or rectangular

  tangular, which has in its center an opening 448, elongate in the vertical direction, communicating with the tube

  suction and defining the weft entry slot.

  The sides 442 ', 444' of the end face of the collar serve as flanges to intercept the weft and the edge

  around the entrance-opening can be advan-

  tagged bevelled or rounded in 450, so as to help

  still at the entrance to the end of the weft yarn. At the in-

  Inside the collar, a series of vertically spaced miniaturized photocell beam generators 452 of the associated transducers 454 were mounted.

  being arranged along the opposite sides of the slot of

  elongated in a multiplicity of vertically spaced points

  tically, for example three in number. the response of such a set of cells is more reliable than a single

  large cell because small cells are more sensitive

  interception by a thin wire, while the

  multiplication of cells increases the speed of de-

  tection of the frame. As will be described more fully

  In connection with the circuit diagram of Fig. 21, the output signals of the photoelectric detection transducer are amplified and transmitted by a suitable circuit to a clutch actuated by a winding (not shown) which controls the transmission of the power of the engine of the craft to the crankshaft of the craft, so as to automatically bring the craft to stop in case a pulse signal of one or more cells, indicating the arrival of the frame, do not

  would not be received within a set interval of the duty cycle.

  the profession. This interval may vary, but

  preferably it starts when the crowd opens up

  than allow the insertion of the frame, that is to say about 1400 of the cycle, and ends at the position of

  dead center before the trade, while the shutter is

  in its full threshing position, that is to say at

  3600. This interval may be established by means of

  breakers and excited from the crankshaft

  of the trade at the appropriate points of its rotation.

  As is evident from the end view of the receiving vacuum tube 440, 440 'shown in FIG. 2A, the axis of the tube 440, 440' must be, during insertion of the weft, substantially opposite the axis of the discontinuous weft guide tube T inside the open shed S, this axis being necessarily spaced forwardly with respect to the plane of the comb R. Consequently, if the tube of reception remained fixed in this position during the threshing, its axis would be in front of the line of tightening of the pick (which coincides with the plane of the comb with the dead moint before) and, as one arranges so that the length free of weft protruding out of the crowd be as short as possible, eg 2.5 to 3.8 cm, so as to minimize waste

  resulting when these protruding lengths are final-

  cut and detached from the fabric and that the ends

  weft that could have been brought could be

  when the gate approaches the front dead center, this could result in the free frame end being dropped at the very moment that this end needs to be restrained.

  positively for the formation of the selvedge.

  Therefore, the receiving tube is preferably mounted to be able to effect a limited independent relative movement on the leaf, as seen in Figures 2A and 23. For this purpose, a bracket 460 is attached to the end of the leaf and on this console pivots an angled return lever 462, substantially vertical, which

  carries the suction tube 440 at its upper end.

  The lower end 464 of the bent lever is connected to a collar 466 attached to one of the guide rods 55 forming part of the vertically movable support of the discontinuous weft guide tube T. Thus, when the leaf pivots backward and that the guide rods slide upwardly to introduce the weft guide tube into the shed that opens before the weft insertion, the collar 466 also moves upwards to

  rotate the angle lever 462 and bring the tube of

  rotation 440 to the alignment on the axis of the guide tube

  ge. On the contrary, when the leaf pivots forward in the threshing position and the weft guide tube

  is retracted down below the crowd, the

  Fig. 462 tilts backwards to move the axis of the suction tube rearwardly with respect to the axis of the guide tube and coinciding with the plane of the comb, which is possible because the tube suction is located outside the end of the comb. Any lateral spacing between the location of the collar 466 and the elbow lever 462 can be filled by extending

one or more of the pivots.

  For some purposes, the commitment of the

  free frame by suction in the receiver tube

  The weft is advantageously reinforced by means of a positively acting weft end plier 470 (see FIGS. 18, 2A and 2B). Such a clip may be constructed in the receiving tube by cutting a slot in one side of the tube 440, as seen at 472, to input a weft clamping coat 474.

  worn at the upper end of a vertical finger 476.

  The finger 476 is pivotally mounted at its end

  lower 478 on the angled lever 462 so as to

  see moving block with the lever elbow and the receiving tube 440 it carries, while also being

  capable of limited independent pivoting movement.

  Below the point of articulation the finger includes an extension 480, directed forwards at an angle, which is adapted to come into contact with an adjustable fixed stop 482 of the leaf when the angle lever 462 is in the forward position ( and that the leaf is in the back position) during weft insertion, thereby pivoting the clamping liner 474 out of the tube slot 472 and allowing

  at the end of the frame to freely enter the opening

  ture of the receiving tube. Then, when the angle lever 462 pivots backward during the threshing, the finger 476 switches with it, which raises the extension 480

  by moving it away from the stop 482 and allows the finger 476 to

  being pushed forward by a spring 484 leading to the seat of the receiving tube 472 so as to bring the fur 474 in contact with the inner wall of the tube,

  with the end of the frame taken between them.

  (h) With regard to energizing the weft inside the shed, once this weft has been fully inserted through the shed and its leading end is engaged by the suction of the tube reception V provided on the receiving side of the crowd, it may be desirable in some cases to apply a voltage to the weft length in the crowd before it is driven against the clamping line

  of the E pick. Unless the inserted weft is

  due to its interlacing by the chain during the

  mation of the crowd, any game or slack it presents will be

  blocked in the tissue producing visible defects.

  If the insertion phase is performed correctly, the weft can usually be passed through the crowd with adequate tension, but if such a difficulty is actually encountered, it can be

  overcome without the need to seize material

  and extend the protruding outer rim end, which would undesirably

  externally protruding length of the weft thread and

  would grow as a result of the amount of waste formed during

the manufacture of the fabric.

  The tension can be obtained very simply

  of the weft in the interior of the crowd in use

  reading the modified form of receiving tube of Fig. 18, which includes a positive end weft end clamp 470, and adding an adjustable wire tension unit, which may be incorporated into the voltage detector 338 of FIG. 14, on the frame of the loom, at an intermediate position between the balloon guide and the output flow clamp of the weft, and also by modifying the operating cycle of the flow clamp to make the latter be promptly released once the free end of the weft yarn has reached the receiving tube. the force applied by the adjustable tensioning device is set to the desired tension level in the weft length inside the shed and in all cases is greater than the desired tension in this length inside the shed and any case larger than the force applied to the frame windings stored in

  the frame storage part by the air ring and the ef-

  fet Coanda. Thus, the free end of the frame will be maintained by the receiving clamp 470 which moves with the leaf, while part of the frame located in

  upstream of the insertion nozzle N is maintained by the

  tension tee which is stationary on the craft.

  After inserting the weft thread, when the leaf pivots a few degrees forward from the rear dead center, the 470 gripper operates

  in order to grasp the leading and leading edge end

  subsequently naked to grab the free frame end after the output flow clamp has been released. when the leaf is approaching the forward dead center during the threshing phase, the distance between the insertion nozzle and the stationary adjustable tensioning member must increase (because the hypothenuse of a right triangle is

  always longer than a basic cost) and this change

  The intervening wire length is used to apply a rectifying voltage force to the inserted weft. The adjustable tensioning member, located between the output flow drum and this thread length, is adjusted, as indicated, to a level consistent with the

  the desired tension force which must be applied to the

  inserted me. Therefore, when the leaf moves forward, while the free end of the frame is held fixed by the receiving clip, the body

  adjustable tensioner grips and holds a part of

  opposite the frame until the voltage across the entire inserted frame length exceeds the set voltage force. Subsequently, when the continued movement of the leaf requires more weft, the adjustable tensioning member yields to pass, from the storage part, the amount necessary for the inserted weft length to move jointly with

  the fighter. In this way, the natural movement of

  the leaf is used to print the inserted weft

  desired degree of voltage, so that the frame is

  venably strained for the hype against the line of

  tightening of the pick without recourse to special

to eliminate slack.

  (i) Regarding the formation of the fabric edge, it should be noted that the fabric produced by the weaving system of the invention, like any other fabric, must

  be suitable for further treatment, such as

  re, printing, reaming or processing

  similar, and must be able to withstand the

  nipulation implied by the execution of these operations.

  Thus, the fabric must be able to be grasped on its edges and stretched without appreciable fraying. In

  normal weaving, when the weft travels without interruption

  rush in one direction and the other through the crowd, we form an edge of edge fabric that presents

  the resistance needed to resist the tension

  because its end loops revolve around

  each end of the chain and actually bind that

  in the body of the fabric. But, with the fabric obtained by the present invention, the weft is always inserted from the same side of the shed as discrete individual lengths of yarn, the weft being cut off near the edges of the shed, leaving its ends free to hang freely along

  edges of the chain. It is obvious, since these extremes

  free weft tees can move unhindered in any direction, they can not resist

  the inherent tension in the chain ends

  in a sinuous way; therefore, the warp

  the outermost will be released and likely to

  filocher, which loosens the next warp thread allowing it to unravel in turn and so on. This problem exists especially on the receiving side of the

  because, in contrast with the flow side of

  where the protruding length of the weft is entered

  positively in the flow clamp, preferably

  that the cut at the point of the seaming line of the fabric takes place, the free weft end of the receiving side of the chain has only a slight tension imposed on it by the vacuum receiving tube that is not suitable for holding the wires of

chain in place.

  In the prior art, different

  techniques for forming a selvedge of fabric presenting the

  intact condition necessary for further handling.

  In one case, pliers were used to grasp each outwardly projecting weft end and to engage it in the next created shed so as to artificially form a loop that secures the outermost warp yarns in place. In another case, a group of two or more warp yarns is attached by means of a gauze stitch and an additional group of about 20 to 30 warp yarns is provided outside the location. of said chain point so as to obtain what is called a false

  edge. The frame is long enough to

  tie with this extra group of warp yarns and the result is a marginal band that is suitable for grabbing during handling. The extremities

  weft are hanging outside the false

  which allows for fraying, but this has little

  tance, because once the threshing is done, the wrong tape

  The selvedge is separated from the rest of the fabric and discarded.

  In both cases, the result is the loss of an appreciable amount of yarn. In the

  first case, the return of the frame ends

  lie provides dense edges at the edge of the tissue, edges that are easily distinguished from the body of the fabric and need to be cut and removed before the fabric is used; while in the latter case it is the false edge band

  itself which constitutes the waste.

  Since, with the present weaving system, it is particularly intended that the amount of waste resulting from its operation be reduced to a minimum, an improved seam forming technique, as seen in FIG. use preferably. With this technique, a gauze chain stitch is first formed in association with the three or four outer warp threads shown in FIG. 36, at least on the receiving side of the chain, and for this purpose a conventional gauze device of a kind that is commercially available, is mounted on the front rail of the craft, as shown schematically on the

  figure 1. As is well known in the art, the provision

  two-piece shaped gauze 490, shaped like a

  guilles, arranged in the vicinity of a corner of the smooth

  before H, and substantially parallel to the plane of the

  each needle having an eye (not visible) at its lower end through which passes a gauze thread (dotted with dots) in Figure 36, which comes from a winding (not shown) supported at the back of the frame of the craft through one of the guides 492 mounted on the rail. The two aforesaid needles are mechanically coupled by a member contained inside a casing 494, so as to undergo a shift of 1800 in their relative positions each time the front arm rises in the raised position, so as to oscillate in a sense and in the other compared to the three or four

  outermost chain ends for

  cross the gauze threads on these chain ends.

  When the front beam is in its upper position

  the warp yarns generally follow the

  the upper side of the crowd in front of the rail, and then lie on top of the next frame. When the front beam is in the lowered position, the gauze threads generally follow the corner angle of the upper side

  from the crowd in front of the rail, and then place themselves

  above the next frame; while, when the front beam is in the lowered position, the gauze son generally follow the lower side of the crowd and then move under the next frame. In this way, around the outermost group of the three or four regular chain ends a sort of intertwined chain stitch is formed to bind them to the body of the fabric, as indicated by the gauze threads on the body.

figure 36.

  In operation, assuming, for example, that two loom frames are used in the loom, the gauze yarns will wrap below each other weft yarn and then intersect each other, i.e. 'they

  change their position over each interposed alternate weft yarn. If the number of stringer frames is greater than

  or more, the gauze threads can crisscross over a weft and pass below the two or more remaining wefts before

restart.

  The resulting gauze chain stitch is not sufficient

  did not do it alone to effectively bind the outermost warp threads to the body of the fabric. The free frame end being, as already explained, completely free to move without any restriction, the handle of each winding of gauze thread below a frame which has just been inserted will immediately disengage as soon as possible.

  that it is energized during the following oscillation

  the needles of gauze, destroying the effect of

chain stitch.

  To solve this problem by means of the invention, the gauze point point is associated with a point of

  rotating binding seam. In order to create the point of

  tying, a support plate 496 (FIG.

  1) for two bonding yarns G (shaded for their identification

  FIG. 36) is mounted on the receiving side of the shed and reproduces in duplicate, on the same side, if desired, at a location on the frame of the loom on the warp beam or backside of the rails. , the plane of the plate being disposed vertically and its axis of rotation being, in the assembly, parallel to the axis A of the leaf. On the outer face of this plate is a pair of feed coils of

  binding yarn 498 and G yarns therefrom

  tation pass through flexible metal wires

  500, thread tensioners, which protrude into dia-

  opposite sides of the plate. A money device

  Adjustable movement (not shown) attacks each spool to tension the thread that is extracted therefrom. The tension-flexible threads 500 extend in the radial direction from the periphery of the plate to define between the guide eyes, at their respective ends, a spacing substantially equal to the back-and-forth stroke of the H-rails and the bonding yarns G go guide eyelets

  terminals at the clamping line F of the pick.

  Support plate 496 rotates continuously

  naked at a synchronized pace on the operation of the loom, so that the plate rotates 180 at each cycle of the trade and with 5 to 10 in advance, or out of phase

  compared to this cycle. Thus the binding threads G are

  place alternately upward and downward, like the movement of formation of the crowd of the warp threads, but slightly out of phase, while being at the same time

  times twisted around each other at the rate of one half

  twisting tower per operating cycle of the craft.

  This torsion effect is in principle the same as if the axis of the support plate was parallel to the direction of the

  instead of being perpendicular to it, the only difference

The reason being that the rotation of the plate causes the body of the binder wire supply winding 498 to move closer to and away from the clamping line E, which would introduce slack into the wires.

  of binding G if there were the guide wires 500 of the sup-

  Harbor. These tension yarns 500 are designed with sufficient flexibility to keep the bonding yarns G under tension during the rotation of the support plate 496, so that the bonding yarns G remain stretched at all times along their entire length. up to the tightening line of the fabric. The slightly advanced moment of rotation of the support causes the connecting wires to pass through a frame

  newly inserted as soon as possible and, consequently, the former

  free end of each frame is immediately pinched, during its insertion, between the binding son. In this way, each end of the tramelibre is gripped by the bonding yarns G twisted together and held in place until the gauze chain stitch can be

  finished around that frame end.

  It has been found that the combination of the point of

  gauze chain and twist stitching stitch

  d allows to obtain a well intact fabric edge and allows it to easily withstand all

  efforts that may be imposed upon him during the opera-

  conventional finishes of the fabric. While the former

  trenches protruding from the weft are necessarily

  like loose bangs, this does not cause the bonding stitching to deteriorate, because the twisted nature of this stitch works by pinching

  the free weft end between the oppo--

  and keep it in place until weaving

  progressed and that a sufficient number of new

  Weft hems were added to coat all yarns with sufficient density or clamping to hold them in place after loosening the weave tension. For some purposes the bonding seam alone may exert adequate restriction on the weft ends, so that the gauze point could be removed, but it is preferable to use the combination of the two dots to obtain the optimal results. . In either case, it is not necessary to remove any part of the edges of the fabric, as is necessary with a false edge or with a selvedge edge, because the density of the fabric remains uniform almost until its extreme edges and the

  waste is therefore reduced to a minimum.

  (j) With regard to the air circuit of the

  according to the invention, it will be exposed to help understand the operating mode by means of

  of the "air" circuit diagram including the pneumatic components

  Figure 20. On this diagram, air from

  from a suitable source of compressed air (not shown) passes through a coarse filter

  510 to eliminate oil contaminations and

  solid particles such as dust and the like,

  above 20 microns for example of size, and is ad-

  placed in a high-pressure line 512 and in a

  low pressure 514, these pressures being determined

  by respective appropriate regulators 516 and 518.

  The high-pressure pipe 512 has several branches, the first of which 520 communicates directly with the storage chamber 75 of the insertion nozzle.

  N or, preferably as shown, with the

  accumulator 137 and, through that

  accumulator, with the accumulation chamber of the nozzle.

  A second branch 522 passes through an electro-

  valve 524 which can move between a position of de-

  bit and an evacuation position to go to a

  (not shown) of the actuation system of

  the dosing and weft storage unit so as to de-

  break this coupling and stop the frame build-up on this unit when the solenoid valve is energized,

  for example during the release or replacement of the

  tier to repair a broken or incomplete frame.

  Another branch 526 goes through a 528 filter

2478144 '

  capable of removing particles from about 3 microns and is connected to the input of the control unit U of the weft insertion nozzle (seen in the embodiment of FIGS. 8 to 10) to debit under the control of this unit in the control input pi-

  lote 117 of the insertion nozzle N itself. A quad

  third branch 530 passes through a solenoid valve 538, maneuvering

  true by hand, which has debit positions

  feeding and evacuation and goes to a feed hole

  mentation (which may be the same as the

  pressure rim 181) connected to the supply passage of the furnace so as to allow the outlet orifice of the nozzle to emit pulses of air by direct actuation of the valve 538 by an operator, regardless of the unit nozzle control unit U itself. The low-pressure duct continuously feeds the air ring

  340 of the dosing unit and frame storage.

  (k) In FIG. 21, the circuit diagram of the circuits of the electrical components of the air circuit and other related components (excluding the mode

  electrical realization of the control unit U),

which one will refer now.

  As has already been said, it is possible to

  the weft output flow clamp by a

  noide spring-loaded, excited by a micro-interrup-

  it is itself actuated by a rotating cam, which rotates with the crank shaft of the loom and which is profiled so as to open and close the switch and therefore the clamp at the appropriate moments. But it is obvious that it would be difficult to adjust these moments by means of such a device. It is therefore preferred to operate the

  weft output flow clamp using two soles

  separate training aids in opposition who are

  coupled together and at the head of the clamp and which are

  excited alternately at the correct times. To this effect

  As can be seen at the bottom of Figure 21, interruptions

  Separators 550 and 551, opening and closing the clamp, are each connected on one side to a line 549 at 12 volts DC and on the other side to a terminal

  respective different from an integrated flip-flop circuit 552.

  Each of the outputs of the flip-flop is connected to the base of an associated power transistor 555, 556, which is connected in series to one side of a corresponding solenoid 557, 558, the other side of which is connected to line 549.

  DC to complete the circuit. When the

  switch 550 opening of the clamp is closed, the tran-

  sistor 555 is excited to allow a current of cir-

  flow into solenoid 557 to open the flow clamp

  frame output; and conversely, when the interrup-

  Clamp closure 551 is closed, transistor 556 is energized to allow current to flow into solenoid 558 to close the output flow clamp.

frame.

  FIG. 37 shows a preferred device for actuating the switches 550 and 551, the latter having the form of Hall effect switches, mounted at radially separated points on corresponding arms 559, 560, which pivot on a tree

  561 which rotates with the crank shaft of the craft.

  Magnetic actuators 564 and 565 are carried by separate disks 562, 563, fixed on the shaft 561 to

  to turn with it, in corresponding points radial-

  distant, so that each actuator rotates in a circular path that coincides only with

a Hall effect switch.

  As has been said, it may be important to have close control over time, within 1 to 2 ms, of operating the output flow clamp.

  weft and the opening interval of the

  bit must be adjustable. It is possible to make a rough adjustment of the relative positions of the magnetic actuators 564 and 565 by means of a pin junction and slot which can be clamped. In addition, a fine adjustment is obtained by constituting the ends of the arms 559, 560, in the form of toothed segments as can be seen in 567 and 568, which can mesh with sprockets 569,

  570, mounted on the frame of the loom and fixed by

  springs or ratchets (not shown) in any rotational position. The arms pivot independently on the shaft 561 and, by rotating the gears 569,

  570, the peripheral positions can be

  relative strengths of the arms and therefore switches

Hall effect themselves.

  Normally, a profession incorporates what one appeals

  shovel a stop motion, plugged between a source to

  12 volts AC and the ground and including an interrup-

  540 mercury cell associated with the working position (which

  is normally closed as shown in Fig. 21).

  A wire drop switch 542, responsive to the drop of the warp threads (not shown), which must close

  when a warp breaks, is connected in parallel

  a hand switch 543 for stopping the loom and both are connected in series with the switch 540, while the "stop movement" solenoid 544 "of the loom controls a coupling (not shown) which

  transmits the torque of the craft engine to the crankshaft

  brequin, so as to automatically stop the job

  if any warp breaks in the course of

  tion or if the manual switch 543 is

  closed. This circuit is conveniently used in the invention

  to stop the loom in the event that the alignment of the photoelectric frame detectors does not detect the arrival of the leading weft end at the instant

  suitable. For this purpose, the output of a triac or thyris-

  tor bidirectional 546 is also connected in series with

  the stop solenoid 544 via the inter

  mercury breaker 540, while being in parallel with

  the wire drop switch 542 and the wire interrupter

  543. The output signal of the alignment of

  photodetectors and transducer transmitters 452, 454 (

  FIG. 19) is amplified, for practical reasons, by an operational amplifier 545 and applied to the input S of an RS 537 flip-flop whose Q output is open and the Q output is connected to a terminal of an AND gate 534 A restoration pulse is derived from the pincer opening switch 550 and after being extended into

  a pulse expander 531, it is applied to the

  R of the flip-flop 537, the duration of the widening of up to a few ms after the dead point before the

  job. A clock pulse, deduced from the interrup-

  The clamp closing device 551 is supplied to the other terminal of the AND gate 534 after being delayed at 532, so that its arrival coincides exactly with the forward dead center of the loom. The output signal of

  AND gate 534 is applied to triac trigger 546.

  Unless interrupted by the arrival of the frame, the photoelectric alignment conducts the current continuously and the input S of the flip-flop remains at logic 1 which maintains the output Q at logic 1 and the output Q to O logical. Thus, if no weft yarn arrived at the moment when the loom reached the dead point before, the two entries of the AND gate are at 1

  logic and a pulse goes through this gate to de-

  snap the triac and excite the movement's solenoid

  Stop. If a frame actually arrives, a logical O momentum

  tané is received at the S input which excites the latch so

  to make Q, O logic, and Q, 1 logic. As the enlargement

  pulse generator 531 maintains the logic input R 1 until after the dead point before, the rocker maintains

  Logical O whatever the subsequent fluctuations

  the R input between 1 logic and 0 logic. Upon termination of the extended restoration pulse,

  input S returns to logical O, which restores the

  to make Q come to logical 1 and logical Q to O.

  If the frame arrival detection alignment failed, the loom is automatically stopped, because any interruption of the photoelectric output signal excites the flip-flop 537. When one has to work on the loom to correct the defect due at the non arrival of the

  frame or because of other difficulties, we will open

  540 mercury switch to disconnect the solenoid

  stop and simultaneously to restore the triac 546.

  A release switch of the loom 548, mounted on the actuating lever, supplies AC power to the clutch solenoid valve 524 of the weft supplier to disengage the clutch of the clutch.

  frame supplier and to avoid tangling or

  Extended weft wetting on the supplier, while the craft crank shaft is moved by hand to perform the necessary repairs to the fabric or craft. Similarly, the solenoid 538 which controls a valve to directly admit pressurized air into

  the insertion nozzle, regardless of the unit of com-

  nozzle nozzle U, is connected on one side to the same power supply line and on the other, to a switch 547 operated by hand and, thereby, to ground. By closing

  switch 547, the operator can apply direct-

  a pulsation of air at the nozzle to project a

frame during the initial threading.

  I. Consideration will now be given to the conversion of

third-party shuttle.

  While the air weft inversion system according to the invention can be advantageously incorporated

  in a profession of original design, any profession

  The new instrument would need a substantial, if not complete, rearrangement of its elements to best utilize the features of the invention and this would involve a large capital investment for the invention to be put into practice in the textile industry. House

  found that the principles of the invention are also suitable

  well to convert existing shuttle looms by making only relatively minor modifications, which will allow the invention to be applied at a much lower cost and will now describe what needs to be done to convert an existing shuttle loom

by putting the invention into practice.

  As in the present invention we omit the shuttle, the classic movements of shuttle chase and

  Shuttle box can be completely eliminated.

  While the flap is kept, the massive beam of the flap, which is usually necessary in the shuttle looms here is useless and undesirable and in

  Consequently it can be replaced by a flapper.

  frame form, which consists essentially of a light channel supporting the frame guide tube,

  the insertion nozzle and other associated components.

  Since the diameter of the guide tube is much smaller than the crowd envelope required for the shuttle, the maximum crowd gap can be reduced by

  minus 30%, for example about 6 cm of green spacing.

  tical for the usual shuttle loom to about 4.3 cm in the art of the invention, which allows several

  other desirable modifications. In the first place, the

  Reduced crowd width implies that the arched path of the wing can be shortened accordingly,

  that is, about 30%, that is, more specific

  but it can be reduced by about 15.2 cm

  shuttle craft to 11.4 cm or less in the case of

  vention, which in itself already increases the speed

drive of the wing.

  Secondly, the reduction of the maximum crowd opening allows a corresponding reduction of

  the vertical stroke of the movement of the harness. As this movement

  The use of harnesses on existing shuttle looms is an important factor in limiting the maximum working speed, this modification is particularly advantageous. The tightening line of the pick as well as the angle of the crowd (that is, the included angle between

  the chains separated from the crowd) stays here without changing-

  is lying. However, the movement of the harness can be shifted forward from its usual location relative to the wing, but this can be done with little difficulty, especially since most existing looms already have means to settle

the position of the harness.

  With these modifications and subtracting the additional weight of the particular constituents

  and inventives, the overall weight of the profession and

  of its parts making a movement of

  back and forth can be reduced by one hundred kilograms or more; by con-

  it takes about 16 to 20% less power

  to train the profession of the invention; for example,

  about 3/4 to 1 CV instead of 1.2 CV for a trade

  Shuttle. The end result of all these economies is

  put to have a profession transformed able to work at a speed 2 to 3 times higher than the maximum speed of the traditional shuttle crafts, with an expense which is 10 to 20% of the cost of a new profession completely

  Iep. The system of the invention will now be described.

  (a) First, during the detailed description of the

  In the previous apparatus of the system of the present invention, a great deal of information has already been provided, directly or indirectly, on the mode of operation corresponding to the practical use of this apparatus. Nevertheless, certain conditions of

  have a particular importance for the invention.

  tion and require a more detailed description of the

  accompanied by real test results.

  Some preliminary general comments

  may be necessary to understand the results-

  these essays which basically imply the projection of

  through the chain of a standard 122 cm loom, a suitable length of yarn extracted from the weft metering and storage device described above,

  through a "standard" frame guide tube

  a given combination of nozzle conformation and test conditions. For this purpose, a "standard" guide tube has a length of 122 cm and is composed of 310 uniformly spaced annular elements, ie one element every 12 warp threads, each having a thickness (i.e. an axial dimension) of 0.3 cm and having a rectified internal bore of 1.9 cm in diameter. For each test, the nozzle feed chamber and the accumulation tank, if present, are filled with compressed air to provide "pressure

  given by means of a permanent communication

  with a main source of the same pressure and the actual values of the "supply pressure" are

  measured by means of a pressure gauge (not shown

  communicating with the inside of the food chamber.

  the nozzle. A feed tube, which has an outer diameter of 0.24 cm, is disposed inside each nozzle so that its free end protrudes about 0.3 cm beyond the exit plane of the nozzle.

  the profiled part excluding the cylinder of prolongation

  if it exists, and the screen to be projected is introduced into the feed tube so that its leading free end protrudes a short distance, for example about 2.5 cm outside end of the feed tube, with practical simulation of a weaving state in which the weft is

  cut between the nozzle and the edge of the fabric.

  After the nozzle has been excited or "triggered" with a sufficient level of supply pressure, the weft length will be projected through the nozzle

  and in the guide tube. For a nozzle arrangement

  re and a set of test conditions given, we have

  found that the time necessary for the

  the length of the frame passes through the whole of the

  tension of the guide tube and emerges out of its far end, is reproducible with a reasonable level of accuracy, and this time interval, to which reference will be made here as "weft arrival time", is a useful feature for evaluating the efficiency of

  special test conditions. To have an evaluation

  coherence, a distance of 132 cm has been set as the practical test distance

  measure these frame arrival times, this distance

  including the guiding time itself and a

  enough at each end to get closer to what would be necessary in practice on a trade

122 cm.

  The technique used to measure the "frame arrival times" is: Unstroboscope is

  placed at the fixed test distance from the nozzle (to the ex-

  interior of the outlet end of the guide tube), the

  strobe being excited by means of a clock

  adjustable valle, calibrated in microseconds, which is de-

  triggered by the excitation of the nozzle itself, so that the "flash" of the lobe appears after passing any time interval that has been set on the clock after the moment of the excitation of the nozzle. The exit end of the tube is then visually observed by a human observer to see the location of the end

  leading the frame when the strobe illuminates.

  The test is repeated by trial and error with appro-

  clockwise until we see that the leading end of the weft just reaches the test point at 132 cm at the moment of illumination. This technique is simple, with a good degree of reproducibility, and practically free from human error, and can be easily recorded for subsequent conformation by a camera pointing at the test point. Once the appropriate clock reading at the arrival time of the frame is taken, the test is repeated one or more times to ensure accuracy. With

  measures thus carried out, we obtained with a uniform

  reasonable time frame arrival times, accurate to

a millisecond (1 ms) close.

  The excitation of the nozzle generates a pulsation

  air in the guide tubes and the emergence of this

  air can be detected (and actually detected by hand) and here also the time required for the flow of air to cross the given fixed distance, namely 132 cm,

  is generally reproducible for a set of condi-

  given and it was found that it provided an indica-

  the maximum theoretical return that a given provision can provide for a given set of conditions. The period of time for the pulsation of air to pass through the tube and reach the fixed end point is indicated here as "air arrival time" and is preferably measured by means of an anemometer with hot wire located at the fixed point and connected to the oscilloscope

  recorder that measures the time interval in milli-

  seconds between the excitation of the nozzle and the response of the anemometer. As is known in the art, a hot wire anemometer modifies its electrical resistance.

  that in response to fluctuations in its ambient temperature

  These resistance variations can be detected by a recording oscilloscope. As a modification

  the speed of ambient air around the hot wire

  temperature fluctuation in the metallic wire

  that this device actually detects the instantaneous arrival

  tane of the airflow at the fixed point.

  As is well known by the laws of the

  flow of fluids, the pressure-which is actually obtained at the neck of a nozzle is almost never the same as the supply pressure or the pipe, because the level of pressure that can "see", c ' that is to say, get to the neck of the nozzle will necessarily be affected

  by the inherent impedance resistance in the connections

  between the supply ducts and the nozzle itself. The term "charge pressure" or "stagnation pressure" is used in the art to distinguish

  the actual nozzle pressure of the feed pressure

  or conduct, and this distinction is followed here.

  Specifically, the term "load pressure" or its equi-

  are worth, the "stagnation pressure", is used in the

  description of the various tests carried out here, is planned

  to designate the pressure measured by a strain gauge pressure transducer which is mounted toward the center point of the outlet flow passage of the nozzle, upstream of the neck, as indicated by the dotted lines 114 on the FIG. 4, the signal provided by this transducer being applied to a recording oscilloscope. Moreover, the term "supply pressure" designates this pressure, measured by a gauge connected to the feed chamber, which will be in equilibrium with the

  driving pressure before excitation of the nozzle.

  Starting from these preliminary explanatory observations we will now deal with the conditions of

* particular operation.

  (b) With regard to the pressure of the nozzle, it will be noted

  that it is of critical importance in the present

  that the "charge pressure" of the nozzle is sufficiently large to achieve a "quenching" state at the throat of the nozzle itself and not upstream or downstream.

  downstream of the nozzle neck. The term "suffocation" (or "foreign

  "drift") is derived from the field of aeronautical testing, for example tunnel tests, and it is assumed that it refers to the supply to the nozzle of pressurized air sufficient for the velocity profile across or across the the flow of air passing through the area of the neck is uniformly equal to the speed of sound, that is, it has a speed of Mach 1.0. of the nozzle will be "stifled" in this sense when the ratio of the actual pressure or stagnation pressure to the collar itself at ambient pressure is at least 1.894 / 1. In contrast to aerodynamic test experiments in which

  choking is an undesirable phenomenon, it is essen-

  In the practice of the present invention, a quenching condition is produced precisely at the neck of the nozzle and not before or after this neck, in order to maximize the thrust capacity of the nozzle on the wire.

arranged inside.

  Thus, the collar of the nozzle of the present invention

  This should be the point where the maximum impedance in the flow links between the pressure source and the nozzle neck occurs, including impedance due to flow turbulence as well as boundary layer phenomena. The term "boundary layer phenomenon" refers to the tendency of a fluid layer, in the vicinity of a surface or boundary

  stationary, to be practically stationary and to exercise

  a resistance to the flow of the fluid along this surface, the magnitude of this resistance increasing

  when the longitudinal dimension of the surface increases.

  With this effect, the air supply components of the

  the present invention are specially designed to enable

  seem to be moving through with loss of

  minimal pedance of any kind, the distances between the

  pressure supply source, ie the chamber

  feedstock and accumulator and the nozzle being

  as short as it is reasonably possible and all.

  the connection ducts having a sufficient size not to have an appreciable impedance. In addition, the flow passages from the feed chamber to the neck are carefully profiled to have a flow

  not turbulent at the same time as a circumferential dimension

  sufficient to substantially exceed, for example by a factor close to 5, the cross-sectional area

  actual neck, despite radial or annular dimensions

  are substantially equal, recalling that the annular neck area of the present nozzle is reduced by the presence

  feeding tube inside.

  As has already been said, the fundamental cause

  of the smothering of the nozzle is the existence of a rela-

  pressure between the nozzle pressure and the ambient atmosphere of approximately 2: 1 and obtaining this ratio is the first indicator of

  the existence of a state of suffocation. Nevertheless,

  Additional cations of this state are provided by the quantitative relationship between the charging pressure and the supply pressure, in that the charging pressure for a quenched tuyere will tend to be closer to the supply pressure, and by the "history" of the pressure obtained for the nozzle during a cycle of operation. If the pressure transducer communicating with the nozzle flow passage

  just upstream of the nozzle neck is used for recording

  Continuous recording, on an oscilloscope, of the pressure at this point during an operating cycle, the form of this record provides a pressure trace or "history of pressure" that reveals information

  important about the nozzle as will be explained.

  When the nozzle length is extended to protrude, for example by means of a tube or cylinder, downstream of the neck region, which may be advantageous for certain purposes, care must be taken to ensure that the length of the nozzle such an extension is not such that it superimposes on the system a subsequent "choking point"

  downstream, which would destroy the critical condition of the invention

  choking directly at the cervix. The effect of cou-

  In the case of an elongate cylindrical tube, the resistance or impedance increases with the length of the tube, the effect of which is comparable to a material tightening similar to a neck or a groove, and in the invention this effect must not be able to grow to create a "virtual pass" smaller than the actual pass and downstream from it. In order to provide a 'comparison between a variety

  different nozzles that can be used with the pre-

  In this invention, extensive tests have been carried out with nozzles of different profiles and dimensions.

  whose results will be provided later.

  (c) As to the outline of the nozzle with respect to the invention, it does not appear to be critical and may be subject to considerable variation. At the beginning of the research underlying the invention, it has been hypothesized that a nozzle designed to produce a supersonic airflow

24781 44

  would be eminently advantageous, if not crucial for the optimal high-speed projection of weft yarns in a trade. Then the quantities provided by the study have ruined this hypothesis in the sense that if a nozzle designed for a supersonic flow is certainly suitable for the implementation of the invention,

  does the same operating efficiency can be achieved practically

  surprisingly, by nozzles

  designed for supersonic flow.

  The conformation of the profiled nozzle for the

  supersonic flow has been thoroughly explored in the field of

  aerodynamics and it is not necessary to give detailed explanations here. In short, a so-called supersonic nozzle requires an outlet opening located downstream of a convergent neck, the ratio of the cross section areas of the outlet opening and the neck being

  greater than 1, while the inner nozzle wall

  re, in the region between the neck and the exit, goes gradually diverging in outline. With such a nozzle, the flow of air at the neck reaches the speed of sound and, if the pressure is sufficient, it undergoes upon entering the divergent area downstream, a relaxation with resulting acceleration at supersonic speeds. The degree of expansion and the resulting flow acceleration determine the maximum velocity capacity of the nozzle, i.e., its effective Mach number, and each nozzle must have its carefully selected construction parameters. agree with its possibility

  number of Mach for the intended conformation, as

  at a given projected pressure level. It is

  It is preferable that the diverging profiling be such as to

  the expansion of the flow under carefully controlled conditions to exclude the possibility of the formation of a so-called shockwave caused by an undesirable overdrive and a subsequent collapse or

  recompression of the fluid stream to restore equilibrium

  free. Also, the pressure at the outlet opening should ideally be exactly equal to the atmospheric pressure for the same reason which is to avoid the formation of a shock wave. Calculations establishing the exact required profiles of supersonic nozzles over a certain range of Mach numbers capabilities have been

  performed in aerodynamics and we can find

  additional practical training on this subject in the article "The Design of Supersonic Nozzles" by A. McCabe, British Aeronautical Research Committee (BARC), Reports

  and Memoranda No. 3340, 1967, while a theo-

  This is described in the book "Aerodynamics of a Compressible Fluid" by Leipmann and Puckett, John Wiley & Sons, New York, 1947, especially at pages 30-37 and 218-232. For the present needs, the precise application of these calculations is not considered essential and

  an acceptable approximation can be obtained for the invention

  simply by establishing (for example with "French curves") a divergent contour gradually curved between the neck area and the exit aperture of

the nozzle.

  In order to establish the behavior of the

  supersonic spun yarns, referred to here as "nozzles

  For convenience, a series of experiments have been

  know on a given profiled nozzle, alone and modified

  by the addition of extension tubes of variable length

  These tubes are uniformly cylindrical with a diameter corresponding to the outlet diameter of the nozzle and a length in relation to the outlet diameter of the nozzle in respective ratios of 5, 10 and 20. In this case the nozzle has been established. with a

  cross-sectional area at the neck of Il mm2, a diameter

  0.44 cm neck and 0.47 cm outlet diameter to provide a Mach number of about 1.5 for a "design" stagnation pressure of 271 kPa. The axial distance between the plane of the area of the neck and that of the outlet opening is 0.30 cm and the nozzle surface is regularly profiled divergently from the neck to the outlet opening. Test results for these nozzles receiving feed pressures ranging from 276 to 827 kPa per increments (68.95 kPa)

  according to the air intake times, the arrival times

  frame weight, as well as the effective load pressures

  affected, are given in Table I below,

  say that the quantities extracted from this table for

  frame and air arrival time according to the pres-

  supply voltage for the four nozzles

  FIG. 22, the respective nozzles being

  according to the legend appearing in this figure.

  The indication "PA" means "no arrival", that is to say that the frame length could not be projected

  the test length of 132 cm in the corresponding state

ing.

  Several conclusions can be drawn from the

  Table I. The effect on the air inlet times in this wide range of supply pressures of the addition of risers to a streamlined nozzle is minimal; the curves representing the air inlet times for the four nozzles are closely grouped

  and are most likely within the limits of

  experiment. But the addition of an extension tube

  significantly improves the weft arrival times for the particular profiled nozzle of this test when operating with low feed pressures, this nozzle exhibiting poor performance at such low pressures, the difference in lengths

  of tube having a relatively small importance.

  On the other hand, for higher operating pressures, the unmodified shaped nozzle, i.e. without extension tube, operates almost as efficiently as the extended profiled nozzles. We see that the charge pressures obtained by this group

  nozzles are approaching the correct feed pressures

  respondantes; so substantially all the energy of the

  supply pressure was actually provided di-

  directly to the nozzle with a low measurable impedance indicating the presence of a smothering at the nozzle neck,

  there is absence or presence of an extension tube.

  The case of nozzles "straight" should be

  In addition to the supersonic profiled nozzles, it has also been attempted for the purposes of the invention to use nozzles which instead of being divergent

  downstream of the convergent neck area, extend into cy-

  lindre, that is to say with a uniform diameter until

  plane of the outlet opening in the ambient atmosphere.

  Such nozzles will be called "straight" here, to distinguish them from supersonic profiled nozzles, and when they are squeezed they have only a maximum flow velocity, at the throat of the nozzle, of Mach 1.0, although leaving the opening of the outlet, the air flowing is under sufficient pressure and can relax in the atmosphere and thereby reach a supersonic velocity in the region around the exit of the nozzle. The air flow path for the nozzle

  is identical to that of profiled nozzles (that is,

  as shown in Figure 4), the only modification

  fication being the replacement of an insertion part

  from the end of the nozzle to give shape and / or-

  different dimension. As a straight nozzle already incorporates a short extension tube equal to about 5xD downstream of the neck, no comparative tests have been made with additional extension tubes for straight tuyeres, but instead have been tested.

  on straight nozzles of varied neck area to

  to measure the effect of increasing the area of the neck on the operation of the nozzle; it was expected that this

  practically the same effect for nozzles

  and for straight nozzles. Among the straight thrusters

  tested there was a cross-sectional area of 11 mm 2 with a neck exit diameter of 0.44 cm (to allow direct comparison with the unmodified profile nozzle of Table I), as well as than two others with areas in cross-section,

  16 and 32 nm2 respectively, corresponding to di-

  collar exit meters of 0.51 cm and 0.68 cm. The same feed tube associated with the profiled nozzle test

  has been used here with its free end

  Just beyond the exit plane of the nozzle, the trench is introduced with a projecting length of 2.54 cm beyond the end of the feed tube as before. The results of the tests of these straight tuyères are shown in Table II and have been reported on the

  FIG. 23, with nozzle sizes of different sizes being

with legends.

  From these results, it is concluded that

  air flow as well as the frame arrival times are generally improved, ie, smaller, in

  increasing the cross sectional area of the nozzle neck.

  Here again, the efficiency of the 11 mm2 nozzle, similar to

  Table I is significantly better at higher than low operating pressures and this behavior is more or less apparent for the 16 mm 2 nozzle. This means that while all the thrusters tried have power or capacity

  for heavily accelerated frame rate times,

  tell me their air flow times, this potential power can be achieved in fact only when their driving pressure has been set to a sufficiently high level, because it is at these high pressures that

  the frame output bit times have an allu-

  re that begins to follow that of the times of arrival of air or to be parallel. It is for this reason that in practice it is preferred that the supply pressure, for a given weft and nozzle, be adjusted as necessary to produce arrival times of the weft varying as a function of the pressure to the same pace as the air intake times, that is to say, it is desired that the supply pressure is in the region in

  which the arrival times of weft and air are practically

  parallel, the optimum functioning being

finally obtained.

  (d) Regarding variations in the capacity of food

  of the nozzle, it should be noted that in all the tests in Tables I and II the source of pressure for all

  the nozzles tested, included a feed tank

  or additional accumulator, designated 137 in FIG. 1, having a volume of 1310.96 cm3 in addition to 98.32 cc of capacity of the feed chamber of

  nozzle itself, this accumulator being connected to the opening

  entering the nozzle feed chamber by a pipe 0.95 cm inside diameter not more than 30.5 cm in length, which is connected in turn

  to a main pressure line presenting the pressure

indicated power supply.

  To illustrate the difference that this ability

  additional power produced on the functioning

  of the nozzle, load pressure traces obtained by an oscilloscope were recorded, using the profiled nozzle of Table I which comprises the 5xD tube at a supply pressure of about 689.5 kPa rel., with the reservoir respectively connected and disconnected, and these load pressure traces are shown side by side in the adjacent figures 34A and 34B, in which each horizontal unit represents

  a time interval of 5 milliseconds, each modification

  vertical unit pressure cation being 206.84 kPa

  The two traces confirm the response time practically

  In the instant case, the pressure rises from zero to a nearby maximum in both cases of pressure.

  689.5 kPa rel. in less than 2 ms and de-

  actually pass this pressure for a very short time before the oscillations of the pressure wave are

  stabilize or amortize after a few milli-

  seconds still. It can be seen, however, that with only the available capacity of the feed chamber of

  nozzle itself, the charging pressure gradually decreases

  after reaching a maximum until, after about 15 ms of the nozzle excitation period, the charge pressure in the small capacity nozzle (98.32 cm3) fell to 482 to 517 kPa rel. about. In contrast, with the feed capacity increased to a total of 1409.28 cm 2, as is preferred, the pressure trace has a substantially flat plateau which

  maintains the full charge pressure on all

  terval of excitation of the nozzle and which falls only one

  once the air flow in the nozzle is positive-

finished.

  the magnitudes showing the effect of the difference in air supply capacity on the air and weft flow possibilities of the nozzle are summarized in Table III below, where it is noted that the high capacity greatly improved performance at low

  pressures and a slight improvement at high pressures.

  Vees. The quantities in Table III are reproduced

  graphically in Figure 27 (with curves

  shine the effect of another variable, that is, the

  Mach number, in profiled nozzles of which we speak-

later).

TABLIAU III

  Effect on the feed arrival times (ms) of the change in feed capacity A. Large capacity (1409.28 cm3) Pressure (ka relt.) 207 276 335 414 483 552 621 682 758 827 d. number of Mach Con nO Bbl nozzle number 1.5 68 63 59 50 39 35 35 33 28 25 B. Small capacity (98.2 cm3) Con 5xD IBb1 1.5 | - | 751 75 52 38 32 28 28 28 26 In pressure traces, for both small and large capacity nozzles, a

  When the "rise time" is over, the feed pressure

  tation remains well above the ambient pressure over the entire pulse interval and a

  distinct inflection or cut, in each trace, only

  when the control valve is moved posi-

  coming into the closed position to cut

  per air flow, the charging pressure then decreasing quite rapidly up to the ambient pressure. This

  behavior indicates that the capacity volume of

  tation, even when it is only 98.3 am3, is very significantly greater than the quantity that can pass through the nozzle neck at the pressure

  pulse interval and that the power supply capacity

  The feeding chamber is actually supplied to the nozzle neck at a higher rate than flow.

of the nozzle.

  The "fallout time" of each trace of pressure

  tends to be a little longer than the "rise time", because residual air in the outlet flow passages between the nozzle diaphragm valve and the neck must drain, but most of the pressure drop occurs almost instantly and the rest

  has no noticeable effect on the operation of the nozzle

  re. As has been said before, a pinch

  conch of the weft must occur only after a

  appreciable decline in the trace to avoid disagre-

frame.

  (e) About the width of the air pulsation

  it can be seen that the results of comparison of

  High and low air supply cities were obtained, as indicated, with a nozzle excitation interval of about 15 ms, like the results of Tables I and II.

  and it is possible to vary this interval for

  specify the duration of the pulsation of air emitted by the nozzle.

  The effect of such a modification for large nozzles

2478,144

  capacity as well as those with small capacity can be seen in Table IV for the profiled nozzle of 11 mm2 area

  Table I, fed at a pressure of 552 kPa relative to

tive.

TABLE IV

  Effect of change in air pulse width A. Large capacity Air supply (ms) Frame arrival (ms) Built-in pressure units 3. Small capacity Frame input (ms) Built-in pressure units Pulsation width (ms)

51 81 101 151 201 251 30 35 40

PA PA PA

33 (28)

1102 11473 11560

  Below the 10 ms level, the nozzle was absolute pacity to project the wire on any

in the case of

the distance of

  132 cm as indicated by the letters "PA" (no

  riveted), but a noticeable improvement with this nozzle for higher working pressures,

  as was the case in Table I and Figure 22.

  In the test with only one small capacity unit (98.32 cm3) only the arrival times for

  several pulse width intervals.

  Based on these data, for the nozzles in question, the width or duration of the air pulsation

  should be at least 10 ms and will be preferably

  in the range of about 15 to 35 ms with the preferred pressure range of about 414 to 552 kPa next

2478 1 44

  the air supply capacity and others consid-

  tions. To provide another basis for evaluation

  possible, areas under the footsteps of

  for the pulsation obtained with the small capacity air supply (98.32 cc) plus a large pulsation

  capacity for comparison, have been integrated to

  a value representing the total quantity of units

  pressure "consumed during the entire pulsation

  These values are shown in Table IV as "integrated pressure units". the weather

  of arrival of weft for the large-capacity nozzle

  laughed a bit from a first value, this

  last being indicated in parentheses. We will see, from

  these values, that the high-capacity nozzle

  (1409.28 cm3) can provide arrival times roughly equal to those of a small-capacity nozzle that consumes approximately 30-40% more pressure energy,

  measured in integrated pressure units.

  (f) As a simulation, we wanted to have a

  basis for assessing the functioning of the system of

  compared to that typically obtained with prior art air weft insertion systems.

  and for this purpose we have imagined a typical simulation of the art-

  prior art, shown schematically in FIG.

  In order to eliminate the influence of the structure of the nozzle on the operation, that of the simulation was in fact the version of lathe N of the invention illustrated in FIG. 4, whose operating diaphragm was removed and the supply capacity volume of 98.3 cm3 blocked by an impermeable filling, for example wax, so that the air admitted by the end opening of the nozzle passes directly into the annular passage of the head nozzle and from there to the outlet passage of the nozzle. The nozzle inlet was connected by an air duct 0.91 m long, 0.95 cm outside diameter, and 0.63 cm inside diameter at the outlet of a Vd diaphragm valve. The inside of this valve was connected in turn by the same tubing over a length of 30.5 cm to a capacity Ca set by the pressure. The snap valve was actuated by means of an air motor rotating at about 400 rpm, the shaping of the cam being

  such that the snap valve was brought into the position of

for 55 to 60 ms.

  In order for the click valve driven by the air motor to be brought to working speed

  before admission of air to it, the capacity of food

  air intake actually took the form of one of the nozzles

  of the invention including the additional reservoir (capacity

  total quoted 1409.28 cm3), the outlet of this nozzle being connected to the inlet of the snap valve as indicated. In this way, one could easily get admission

  instantaneous air to the snap valve already in operation

  The supply nozzle valve is kept open throughout the entire working range of the valve.

  click. the pressure provided by this feed nozzle

  This has been set to establish the desired effective supply pressure on the click valve. All the others

  conditions were the same as in the tests of the

  I and II and the arrival times of air and weft as well as the pressure traces have been deducted and

recorded as before.

* the nozzles used in the simulation of the prior art were the right nozzles of Table II respectively having the same different areas of 11, 16 and 32 mm2, without additional extension tube. the results of these tests are collated in Table V below and are plotted graphically in the figures and where the air intake and

  frame respectively according to the feed pressure

  tation and charge pressure or stagnation of the nozzle. On the basis of these data, we know that

2478,144

  arrival time, for simulation of the prior art

  are virtually independent of changes in neck area (except for the 32 mm2 area nozzle, at pressures less than approximately 334 kPa rel, which provided even worse values), but in all

  they are practically "slower" than

  air stream obtained in the invention. As the time of ar-

  air is a limiting factor for the operation of

  in that the weft arrival times can never be greater than the air intake times, so that the maximum of what can be expected is to obtain weft arrival times. as close as possible, but still somewhat inferior to the air arrival times, it follows that the frame arrival times obtained in the simulation of the prior art are inherently lower than possible with the system of the invention and are in fact never as short as the desired 30ms target, even with a large area nozzle and very high supply pressures. For low supply pressures, the air inlet times obtained with the small area nozzles, in the prior art system, can

  sometimes shorter than those obtained with tuyè-

  comparable in the system of the invention, but this apparent advantage is more than offset by the

  long duration of the pulse interval in the simulation

  tion of the prior art, exceeding four times the

  pulsation value of the system of the invention, with as

  As a result, the air consumption is greatly increased.

  So, comparing on the basis of the energy actually

  consumed, the system of the invention has a

  much better overall In addition, the system of

  vention potentially has a greatly improved efficiency by increasing the supply pressure, which

  can not occur, by their nature, in the function-

  systems of the prior art.

  The "pressure marks" recorded for the various tests in the simulation of the prior art are found in FIGS. 31A to 31I, 32A to 32I, and 33A to 33I, respectively for neck areas of 11 mm 2, 16 mm 2 and 32 ml2, covering at a range of 69 kPa (68.95 kPa) the full range of supply pressures from 276 to 827 kPa rel. and comparable "pressure marks" for the same area nozzles 11mm-16mm and 32mm-2 operating according to the invention

  in the tests in Table II are seen (with changes in

  scale for convenience as shown)

  Figs. 28A to 28I, 29A to 29I and 30A to I with the same pressures. The analysis of these marks shows that for the invention instantaneous

  the maximum nozzle pressure occurs essentially

  independently of the supply pressure,

  That is, it is virtually identical over the entire range of pressures and is only moderately affected by increases in nozzle neck area. Even for a nozzle of large neck area, ie 32 mm 2, the time required for the charge pressure to rise from zero to the maximum, ie the "rise time", exceeds rarely 5 ms and for example in the majority of

  case it is not more than 3 me and often only

  1 ms. Similarly, the above-mentioned "plateau effect", during which the maximum charge pressure persists practically to the full maximum level over the entire pulse interval, is characteristic of all pressure traces representing the pressure system. 'invention. Even for the nozzle of maximum neck area,

  the loss of pressure, from the beginning to the end of the

  is about 5% and never goes up to 10%. The levels of maximum pressure traces,

  representing the workload pressures in the in-

  are very close to the levels of

  mentation. From these relationships, it is concluded that the nozzles of the invention thus apply to the wire a pressure energy with the highest possible yield and

are in the state of suffocation.

  In addition, in the invention, the pulsating portion

  When the maximum pressure is maintained at least substantially, still substantially exceeds, i.e. in a ratio of at least two, the rise time. This means that the pulsation is consecrated

  the vast majority to useful work with a minimal loss of

male "on startup".

  On the other hand, the traces of pressure of charge

  obtained during the simulation of the prior art presented

  have radically different characteristics. In the first place, the "rise time" is, in all cases, even for nozzles with very small neck area, of at least 20 to 25 ms and even more usually and does not become substantially shorter with an area nozzle neck larger or smaller. That is, the slow rise time of the simulation of the prior art is inherent in its air supply and it is not

  improved by varying the area of the nozzle. Conjoin-

  With the prolonged rise time, the pressure waveform of the prior art system does not show,

  after its initial peak, temporary or irrational oscillation

  gularity which would be indicative of a state of suffocation at

full charge.

  Secondly, even though each nozzle, in the simulation of the prior art, maintains a charging pressure on an appreciable proportion of the pulse interval and until the snap valve begins to close upon release. of its actuating cam, thus testifying to a large air supply capacity during the simulation, the level of pressure of charge or stagnation existing inside each of the nozzles during the simulation of the art previous is

  not more than about 60 to 70% of

  and less than the percentages obtained in the invention. In addition, the difference between the feed and feed pressures increases sharply with increasing neck area, so that for the nozzles with the largest neck area, the maximum load pressure is only 25 to 30% of the feed pressure. On the basis of these characteristics, it must be concluded that the nozzles in the simulation of the prior art are not stifled in any case within the meaning of the invention, despite their operation with feed pressures of

same range.

  In simulation pulsations, it is necessary to

  that as much and sometimes more time to reach the working pressures, ie "starting", so that the maintenance of the working pressure opposes a net obstacle to high speeds of operation and

at a high yield.

  (g) Other conditions will now be discussed.

  in the invention and in particular

- the speed of the air.

  Since the substantially equivalent operation of the supersonic shaped nozzles and straight nozzles in the system of the invention was unexpected, attempts were made to verify this operation by measuring the actual velocities of the air pulses at the time of entry. in the inlet opening of the guide tube at speeds greater or smaller than the speed of sound (i.e. Mach 1) and observing the effect of this variation on arrival times of air, over the fixed test distance of 132 cm, as well as the air flow rates measured at the outlet of the tube. This was done by adjusting the distance between the outlet plane of the nozzle and the inlet plane of the tube to obtain supersonic and subsonic air velocities at the inlet of the guide tube, measured by a hot wire anemometer. placed in the input and calibrated as accurately as possible to accurately indicate the air velocity, the output velocities being also measured by a hot wire anemometer. The results of these tests are shown in Table VI below and establish

  that the air intake times are virtually identical.

  whatever the initial air velocity, super-

  sonic or subsonic, although the air outlet velocities actually reflect (but not proportionally) the difference in starting velocities. This

  functioning has been valid for

age of 414, 552 or 717 kPa rel.

TABLE 'VI

  Effect of changing air velocity with a profiled tuvyre Speed Speed Pressure Distance from air to air Time from (m / s) to (m / s) at arrival charge nozzle inlet the outlet of air Ma re_.) and tube of the tube of the tube (ms) 414 2,857 cm 365,76 68,4 28 6,35 cm 273,6 60,9 28,552 2,857 cm 395,2 91,4 26,552 6.35 cm 273.6 76 26 717 5.08 cm 395.2 114 22 717 10.795 cm 273.6 91.4 23

  - As regards the distance between the nozzle and

  re and the guide tube, it follows from the previous discussion that there is a certain latitude to adjust the intermediate space or spacing between the outlet plane of the nozzle and the inlet plane of the guide tube and performed a series of tests to establish the effect of nozzle spacing using a supersonic profiled nozzle, which has a neck area of 11 mm2 and a Mach number of 1.5, with and without extension tube having 5 times and 10 times the outlet diameter of the nozzle respectively, with a supply pressure of 552 kPa rel., a pulse width of 15 ms and a high capacity air supply (1409.28 cmJ) ). The air inlet times obtained when this spacing has progressively varied from 0 to

  24 cm are collected in Table VII. -

TABLE VII

  Effect of the variation of the spacing between the exit of the nozzle and the entry of the guide tube, with and without extension tube Spacing in cm Time No tube nrolonz. 0.635 1.27 1.905 2.54 3.175 3.81 4.445, 08, 775 6.35 6.985 7.62 8.255 8.89 9.525, 16, 795 11.43

12.065

12.7

13.335

13.97

14.605

  , 24 PA PA PA PA Air Supply (ms)

Extended tube Extended tube

xD 10xD PA

2478 14 4

  As a result, it seems that it does not exist

  optimum location for the nozzle and that

  the position of the nozzle within reasonable limits

  can not have any appreciable effect on

  riveted with air. Thus, between about 2.5 cm and a little less

  about 7.5 to 10 cm, satisfactory air-flow times

  are obtained and can be improved a little

  again by adding a short extension tube to the nozzle.

  Beyond a gap of 10 cm, the air intake times start to deteriorate, even with the addition

extension tubes.

  Another factor that may be modified in the implementation of the invention is the Mach number of the supersonic profiled nozzle and, in order to explore the influence of this variable on the outflow efficiency of the weft , we did a series

  tests using super-profiled nozzles

  sonic, which have an identical neck area of 11MM2 with

  increasing exit aperture diameters (i.e.

  ie 0.472, 0.526 and 0.559 cm), which are necessary to obtain with this structure Mach numbers of 1.5, 1.91 and 2. 07 respectively. These nozzles were tested with respect to the arrival times of frame only,

  with and without 5xD tube, at feed pressures-

  in the range of 207 to 827 kPa rel. and large

  The data collected in the tests are summarized in Table VIII and plotted in Figure 27. From these values, it can be seen that a change in the Mach number has little or no practical influence on the yield.

  of the nozzle to propel the weft, although the adjunct

  a tube actually provides some improvement.

  at low supply pressures.

TABLE VIIT

  Effect on the arrival times of the frame (ms) of the variation of the Mach number of a profiled nozzle Frame arrival time (ms) Supply pressure 207 276 335 414 483 552 21 689 758 827 (kPa el .) Type of No. of Mach Con n0 Bbl nozzle 1.5 68 63 59 50 39 35 35 33 28 25 Con n0 Bbl 1.91 PA 70 62 54 36 35 33 31 31 27 Con nO Bbl 2.09 PA PA 72 45 40 34 33 31 29 29 Con 5xD Bbl 1.5 68 58 39 33 30 30 30 28 26 24 Con 5xD Bbl 1, 91 PA PA 53 41 30 25 26 26 24 21 Con 5xD Bbl 2.09 PA 64 43 35 33 33 In Table VIII all the tests included the large feed capacity (1409.28 cm3) for the various nozzles and it will be recalled that Figure 27 shows a curve which represents a test of a Mach 1 nozzle. 5 with a 5xD tube, identical to the corresponding nozzle of Table VIII, but having a low capacity (98.3 cm3) of air supply. Comparing these results, we see the considerable importance of the improvement provided by the addition of the large feed capacity, which is particularly important for low pressures,

  that is, below 621 kPa relative.

  - With regard to the projected energy consumption, the importance of an operational capacity

  in the lower range of feed pressures.

  The invention, which characterizes the invention, is illustrated by the following Table IX which provides a projected power consumption, expressed in kilowatts per minute, of a loom equipped with the system of the invention and operating at 1000 picks per minute, comprising 11 mm2 and 16 mi neck area nozzles, either supersonic shaped or straight, with a pulse duration of 15 ms and a

  large feeding capacity (1409.28 cm3).

247814 44

TABLE IX

  Projected power consumption (kilowatts) Supply pressure (kg / cm2 rel.)

276 335 414 483 552 621 689 758 827

Nozzle area 1i1 mi

  0.323 0.447 0.579 0.721 0.873 1.03 1.203 1.378 1.56

Tile area 16 mm2

  0.473 0.649 0.839 1.04 1.26 1.50 1.73 1.99 2.26

  Thus, the increase in power consumption is not a linear function of the increase of the charge pressure or the area of the nozzle neck, but an exponential function, the energy consumption for a pressure of 621 kPa rel. for example being more

  triple the consumption at 335 kPa rel.

  (h) A "balanced" operating mode will now be described. In the foregoing discussion of the operation of the system of the invention, it has been suggested that it is advantageous to choose (a) a relatively high level of pressure.

  charging, in particular to obtain delivery times

  short rotation times and the maximum possibility of having high operating speeds with (b) a minimum effective duration of the air pulsation, c. that is, about 15 to 20 ms, in order to reduce energy consumption as much as possible. When operating in this way, observation has shown that during the launch, the leading end portion of the weft

  tends to turn back on itself by meeting the re-

  resistance of the air column inside the tube of

  guidance and it was stated that this difficulty was aggravated

  because the measured and stored frame length has been extracted from the drum frame storage portion in a much shorter period of time than this frame end actually passes through.

the breadth of the craft.

  Usually when the frame length

  The project ends its journey, the driving

  brushing finally picks up and arrives at the receiving side of the chain crowd, but occasionally,

  for one to two out of every 1000 in the

  tioning, the leading part turned back becomes entangled

  enough to resist sprawl due to the relatively light energy forces acting on it. when this phenomenon develops, the end

  leading edge does not actually reach the

  the crowd to engage the receiving tube at this location and, if weaving continues, the result is the introduction of a defect into the fabric being woven. As has been described, the system of the invention preferably includes a frame arrival detecting unit for detecting the non arrival of the frame end at the receiving nozzle and for automatically stopping it. weaving operation to allow the intervention of a human operator to correct the

  tissue, but this leads to a loss of productivity.

  because of the downtime required to correct

the failure.

  In addition, the pulsation of air injected by the nozzle into the guide tube actually moves through the guide tube, in the form of a kind of column whose length corresponds to the duration of the pulsation. So the "air intake times", on which

  in the previous description,

  only the arrival of the leading end of the column and the air continues to advance in the tube until the rear end of this column comes out of the tube. If the weft circulating in the guide tube slows or stops, then the rear end of the column

  air continues to advance rapidly, it was found that the former

  free frame trough can be blown "out of its way" by the outlet slot 49 of the guide tube, at

  instead of continuing along the piercing of the tube. Effective-

  If the air column is still in full speed after the weft has been fully extracted and its free end is held in the receiving tube, a counter-shot may be produced, pulling the free end of the weft out of the receiving tube and blowing it out

  of the exit slot 49 of the tube. Once the

  frame free mity escaped through slot 49 a

  lack of weaving or "false pick" is inevitable.

  Examinations have shown that the phenomenon of

  brushing was still occurring at the place of the

  of the leading end, that is to say on the last at 7.5 cm of the frame length, and one possible solution of this occasional problem would be the addition to the frame of an additional length sufficient to that it reaches the receiving side of the chain, even when the creep phenomenon occurs. But it is obvious that with the addition of this additional length during each cycle (it is impossible to predict in advance the particular cycle during which the phenomenon could occur) the amount of waste produced during the

  weaving is increased correspondingly. As a result

  This solution does not correspond to an objective

  important aspect of the invention, which is to bring the

  maximum and the waste to a minimum.

  It has been discovered that the creep phenomenon can be better avoided by adjusting the weft insertion thrust and / or the resistance so as to arrive at a more "balanced" operating mode, in that the necessary time is adapted. to completely extract the stored frame length from the storage portion to the time required to completely project the end of

  this length of weft over the entire length of the crowd.

  Naturally, reducing the pressure of the nozzle causes a reduction in the thrust printed at the weft, all other conditions being equal, and there may be practical advantages to choose a nozzle pressure pressure close to 414 to 483 kPa rel. Most textile mills commonly

  already in operation for the normal functions

  of the spinning mill, compressed air at a pressure of about 517 to 552 kPa rel., which is ideally suited to obtain charging pressures as desired at a level of 414 kPa rel. about and there are obvious practical advantages to being able to use the air supply

  existing spinning tablet. Otherwise we should buy

  special and costly compression equipment and install it to achieve the higher level of pressure required, which would add much to the cost of

practical work of the invention.

  When operating at a load pressure close to 414 kPa rel. as it has just been indicated, the thrust printed on the wire is still a little higher from the point of view of obtaining the balanced operating mode described above and measures must be taken.

additional.

  There are several methods for balancing

  to reduce the frame extraction time with that of the

  jection of the frame. On the one hand, the efficiency of the nozzle for transmitting its pressure forces to the weft end can be reduced, for example by extending the distance between the end of the feed tube

  and the exit plane of the nozzle, for example by increasing

  both the projection length of the feed tube to

  0.952 cm instead of about 0.317 cm as aupa-

  ravant; it is currently the preferred technique. Alternatively, the resistance or "drag" of the weft length during its removal from the weft storage unit may be increased, or by increasing the distance between the balloon guide and the end of the weft drum. output flow, so as to extend the unwinding drum and increase its diameter or adding voltage to the frame upstream of the inlet of

the nozzle.

  The balanced mode of operation has the effect of "stretching" the energy forces applied to the frame over a longer period of time, from which it follows that the extraction of the stored frame length does not occur. does not perform as fast as before, but instead occurs at a speed corresponding substantially to that of the advance of the frame through the chain crowd. Therefore, catching the end

  leading by the length of the frame that arrives is convenient-

  eliminated, resulting in the disappearance of the

phenomenon of cusp.

  Optimal operation is achieved when

  the free frame end comes out of the end of the tube--

  before the stored weft wraps have been completely removed from the storage portion of the drum; that is, the end of the frame leaves

  the guide tube before an initial voltage rise

  it is detected by the voltage detector 338. Idea-

  the arrival of the weft end into the tube

  reception, indicated by the photo-detection

  electric, occurs almost at the same time. that the start of the stored frame end of the storage unit

  drum; i.e. the voltage rise detected

  and the frame arrival signal are substantially concomitant. Operation with similar charging pressures to the available pressures of the spinning lines has another practical advantage, namely a considerable reduction in the time required for the decline in the pulsation of its plateau level to zero. In "balanced mode" operation, the decline in pulsation can be reduced to about 7 ms instead of about 12 ms, which typically characterizes the "high pulse" mode. This allows to extend the plateau phase of

  the pressure pulsation without concomitant risk of con-

  In the meantime, the waving of the pulsation, the fact that the frame is in fact arrived at the reception of the crowd. We have already indicated

  if the pulsation persists after the frame is full

  In a static state, the weft will be wobbled roughly here and there, which brings about its degradation, if not complete disintegration. With the balanced mode the pul-

  pressure can be, so to speak, "stop

  "roughly half the time

  higher pressures; thus, it is easier to

  to know that the pulsation is complete before the frame has taken a state in the crowd. In general,

  it is preferable that the heartbeat has completely

  appeared 2 to 3 ms before the arrival of the end of

  leading weft at the receiving side of the craft.

  We realized that the sacrifice on time

  frame arrival, obtained in accordance with the operating mode

  well balanced, is only minimal. For example, with

  a charge pressure of 414 kPa rel., a duration of pul-

  extended time to about 30 ms and the preferred projection of the 0.952 cm weft feed tube

  air intake time of approximately 23 ms and

  framed frame of about 32 ms can be regularly

obtained with ease.

  (i) With respect to other classical factors

  than those described above, there are some in the

  the system according to the invention, which are not

  not specific, but also found in systems

  of the prior art, so that the description

  complete role they play is not necessary here.

  One of these factors is the nature of the wire itself and, as with the weft inserting systems of the art

  prior art, the system of the invention effectively

  mainly with relatively rough surface frames. Such frames are constituted by natural and natural classical spun strands or

  synthetic and probably also by syn-

  textured surface. So far we have not considered

  dere mono-filaments smooth surface.

  The influence of the size of the weft has not been fully investigated, but the capacity of the various nozzles described above is sufficient to easily cover a considerable range of conventional deniers and no difficulty in using the system is expected. of the invention with such threads, given the possibility

  of the pressure variation inherent in the pre-

  feel system. Frames that have been tested to date include 12 to 50 twisted cotton yarns and all have been woven satisfactorily without

  modification of the operating conditions.

  Another factor is the diameter of the tube

  frame guidance. Summary tests on the bench established

  that it takes a certain minimum tube diameter for that

  the weft is actually transported all the way

  the tube. For example, with the various nozzles

  mentioned above, it is not appropriate to have one person

  inner hole for 1.27 cm tube; only high-neck nozzles (32 mm2) are likely to flow

  completely the wire by a guide tube of in-

  1.27 cm and, even with these nozzles, the

  frame are fairly long, for example of the order of 60 ms. On the other hand, tube drilling diameters of 1.90 cm are quite satisfactory and the numerous tests indicated above were carried out with a tube

  of this dimension, as has been said. The diameter of people

  could probably be increased again without any serious consequence on efficiency, but no particular advantage is seen in this. A reasonable theory is that if the diameter of the bore of the tube is too small relative to the outlet diameter of the nozzle, the tube tends to confine unduly the air pulsation column emitted by the insertion nozzle, in that meaning that there is frictional resistance to its passage and / or discomfort with its freedom to take a certain expansion when leaving the opening of the nozzle. Nevertheless, as long as the nozzle diameter is large enough to

  to give the pulsation of air a dynamic freedom

  male, satisfactory operation is possible and larger diameter tubes, naturally, would give greater freedom. In addition, the guide tube is a critical part of the system and, if

  the omission, the possibility of projection of weft by the nozzle

  re is extremely limited and far less than a width

  of any profession of normal size. The Applicant es-

  time that there is a similar relationship between the prior art tuyeres and the diameter of the tube, although this has not been expressly indicated in the publications

  of which the Applicant has knowledge.

  It follows from the preceding commentary that the

  This system is designed for an association with

  third of "normal size", that is to say, about 122 cm in width or more. Width trades are known

* particularly narrow, for example

  bans, sword looms and similar trades, but the high-speed operation of these trades is possible by other means, for example by means of mechanical transporters, eg swords, because of their less demanding technological requirements and there is little reason to use such narrow crafts with the more sophisticated design mode of the present

system.

  In addition, with regard to the guide tube, it has already been indicated that in the practice of the invention the interior surface of the bore of the guide tube is mechanically polished so as to give it a degree of

  reasonable polishing thanks to a suitable grinding

  corn. The air intake and weft times can be much lower with internally polished tubes, compared to tubes having surfaces obtained by casting or conventional molding. Nevertheless, for the balanced mode of operation, the rectification was not necessary and the careful assembly of the elements at

  trestle provides a satisfactory alignment.

  Axial thickness and repetition of elements

  constituting the guide tube are usually

  undermined by the condition that the elements of the tube

  sufficiently close together to

  actually end the air flow, which can limit the size and number of warp threads, but this limitation applies to any system using a tube

  guidance. Segments having an axial dimension of

  sine of 0.32 cm and spaced from each other by about

  20/1000 to 35/1000 were satisfactory.

  (j) By way of specific example, it will be pointed out that a 122 cm wide shuttle loom, processed in accordance with the present invention, is used to weave printed fabric from 40 twist s yarns spun from a 35/65 blend of unworked cotton and polyester floss and twisted weft yarns spun from the same 35/65 blend of cotton flock and polyester. The total number of warp threads is

  3750 and the combed width of the chain is 130.8 cm.

  The loom is equipped with the nozzle of FIG.

  the high-capacity accumulator and the com-

  is constituted by the mechanical embodiment

  11 to 13. The nozzle is a nozzle

  supersonic spun that has a collar area

  of 11 mm2, a Mach number of 1.5 and an extension tube

  5xD motor providing a load pressure of 4.9 kg / mm2 relative. The end of the weft feed tube protrudes 0.95 cm beyond the end plane of the

  tube, unlike. at the disposal of the feeding tube

  in the different tests of the previous descrip-

  tion, while the feed tube terminated in all cases at the outlet plane of the nozzle orifice to the exclusion of any extension, that is to say the plane designated 88 in Figure 4. The -commerce works at

318 picks per minute.

  A representative operating cycle for the above craft is seen on the recording tape of the

2478,144

  FIG. 1, FIG. 35, which shows the following waveforms in time: a, the excitation, ie the opening and closing of the weft supply clamp 0, 330; b, the pressure of loading or stagnation of the insertion nozzle; c, the frame output rate voltage, as detected by the voltage detector 338; and d, the arrival of the frame to the receiving tube, detected by the photoelectric alignment. The clamp opens to

  1400, remains open for 40 ms and closes at 217 0.

  The insertion nozzle is actuated at 1450 for 34 ms,

  the charging pressure falling to the starting level at

viron 2200.

  With the excitation of the nozzle, the voltage in the weft rises from its previous "noise level", almost in coincidence with the excitation of the nozzle and the perceptible peak in the weft voltage occurs at 2080, indicating the complete extraction of the frame from the storage-drum part, the tension indicator

  weft then falling to its inherent "background" level.

  The arrival of the frame end to the photodetector occurs at 2080, the subsequent peaks e of the waveform

  d being caused by the "floating" of the working end

  me in the receiving tube and being unimportant. The

  frame arrival time is 36 ms and the time of arrival

  of air (obtained by other means) was 28 ms, according to

what we found.

  In this description, the abbreviation "ms"

  milliseconds and "relative kPa", a pressure in

  kilopascals relative to normal atmospheric pressure

  male (translating, with some approximation, the pressure values, usually expressed in round figures,

  but in pounds per square inch, basic text).

  It should be noted that in the invention the working pressure is maintained in the convergence zone of the weft insertion nozzle in a ratio lower than 1.893: 1 with respect to the ambient atmosphere pressure; the ratio of this ambient pressure to said working pressure is preferably less than 0.2724; and preferably the ratio of the maximum area in the divergence zone of the nozzle to the minimum area in its area

convergence is 1.176: 1.

TABLE I

  Effect of extension tubes on a profiled nozzle Supply pressure (kPa) Air inlet time Arrival time Load pressure (ms) of weft (ms) (kg / cm2 rel.) XD 10xD 20xD 5xD 10xD 20xD 5xD 10xD 20xD no Bbl Bb1 Bbl Bbl no BbI Bbl Bb1 Bbl n0 Bbl Bb1 Bbl Bbl

  37 35 34 35 PA PA 56 58 PA PA 276 269

  30 30 32 98 45 42 42 331 331 331 335

  27 27 26 28 53 36 36 34 393 393 414 407

  16 24 25 25 50 34 30 30 462 469 483 469

  24 23 23 24 44 33 29 27 538 538 538 524

  23 22 22 23 33 27 27 26 607 621 621 600

  21 21 20 22 29 27 26 23 683 683 676 669

  20 19 21 27 25 23 23 758 745 758 745

  18 19 18 19 26 23 21 21 827 827 827 827

CD re4 -.4 A, Effect of

TABLE II

  variations in neck size for a straight nozzle Supply pressure (kPa) Supply air time (ms) Collar area

11 16 32

  Weft arrival times (ms) Collar area

11 16 32

  Load pressure (kPa) Collar area

11 16 32

36 28

33 26

29 25

27 22

20

23 19

23 18

18

17

PA 64 45

98 55 39

44 35

49 33 31

48 30 26

36 30 25

30 24

32 21

26 25 20

PA Co A.pr

TABLE V

  Results of the anterior air simulation with straight neck nozzles of various areas Supply pressure (kPa) Supply air time (ms) Pass area 16 3.2 Frame arrival time (ms) ) Collar area

11 16 32

53 68

55

42 50

45

41

38 40

36 38

34

34 32

  Load pressure (Relative kPa) Collar area

11 16 32

552+ 1 38 o 4h Co

2478,144

  1. A method of inserting a weft yarn into the shed of a weaving machine, characterized in that it comprises the following steps: the establishment of a confined area (in N) in the vicinity of the shed (S) for guiding a weft thread (F) passing through said area; and the abrupt expulsion of a sustained pulsation of gaseous fluid, starting from said zone and going towards said crowd, to thus bring said weft yarn into

  at least a portion of said crowd.

  2. Process according to claim 1, characterized

  characterized in that it comprises the step of confining said wire in a preselected path during the passage of said fluid pulsation and said wire through

  at least said portion of said crowd.

  3. The process according to claim 1, wherein

  characterized in that said pulsation is expelled from the eye.

  zone for a preselected time.

  4. The process according to claim 1, wherein

  characterized in that said confined area includes an area

  of convergence for the gaseous fluid.

  5. The method according to claim 4, characterized

  characterized in that said fluid is expelled into an at-

  normal ambient atmosphere and in that it includes the stadium

  to bring said gaseous fluid under a working pressure

  in that area of convergence and to maintain

  said working pressure relative to said pres-

  ambient temperature in a ratio below 1.893: 1.

  6. Process according to claim 4, characterized

  characterized in that it includes the step of bringing said gaseous fluid to a working pressure in said zone of

  convergence, and then expel said fluid into a

  downstream of said confined area, normally maintained

  at a diffSranut pressure of the ambient pressure.

  7. The method of claim 3, wherein

  characterized in that it includes the step of passing, by means of said pulsation, said driving end of said

  thread through said crowd of a first side of said

  and secondly, to limit the duration of said pulsation to a time less than that required for the leading end of said wire to advance from said first side of the shed to said second side of the crowd.

  8. The method of claim 3, wherein

  in so far as it includes the stage of passing

  fluid pulsation through said crowd of a first

  first on her second side and settle

  the duration of said pulsation at a time less than

  the time taken by the pulsation to arrive

second crowd audit.

  9. The method of claim 6, wherein

  characterized in that it includes the step of providing a zone for limiting the expansion of the fluid downstream of said

convergence zone.

  10. The method of claim 5, wherein

  characterized in that said working pressure, once

  that it is reached, is practically constant.

  11. The method of claim 2, wherein

  characterized in that said step of confining said wire includes establishing, through said portion of said crowd, an elongate confinement zone, at

  less partially open to the atmosphere on its

LATIONS.

  12. The method of claim 1, wherein

  teris6 in that it includes the stage of containment at

  less partial of said wire in a guide zone of di-

  preselected meter during passage of said wire through at least said portion of said shed, said fluid expanding after being expelled from said

  confined area, and in that said fluid enters the

  said guiding zone before it has expanded to a

  dimension greater than the diameter of said guiding zone

dage,

2478 1 44

143--

  13..Procdd according to claim 1, charac-

  characterized in that said confined area includes a convergence zone through which said wire passes and in that said wire is protected from contact with said fluid until said wire reaches at least one

  downstream region, with respect to said convergence zone.

  14. The method of claim 13, wherein

  characterized in that said confined zone includes a zone of divergence downstream from said convergence zone and in that said wire is protected from contact with said

  fluid until said wire reaches at least the former

  tremité downstream of said divergence zone.

  15. The method of claim 13, wherein

  characterized in that said confined zone includes an elongate zone limiting the expansion of the fluid downstream of said

convergence zone.

  16. The method of claim 14, wherein

  characterized in that said confined zone includes an elongate zone for expansion of the fluid downstream of said zone of

divergence.

  17. The method of claim 1, wherein

  characterized in that said fluid is air, preferably

  moist and preferably preheated.

  18. A method of inserting a weft yarn in the shed of a weaving machine, characterized in that it comprises the following stages: the establishment of a confined area, in the vicinity of said shed, serving as guiding for a weft thread passing through said area; and generating a pulsation, of given duration, of a gaseous fluid which passes through said zone and which is directed towards said crowd to thereby convey the driving end of said weft yarn through said crowd, said duration being less than the time required for said end of wire through

said crowd.

  19. Method of inserting a weft yarn into

2478,144

  the crowd of a weaving machine, characterized in that it comprises the following stages: - the establishment of a confined area in the vicinity of a first side of said foula, serving as a guide for a passing wire passing through across said area;

  - Generating a pulsation of a gaseous fluid not

  passing through said area and directed to said shed to thereby convey the leading edge of said trane wire from said first side to a second side of said shed; and - limiting the duration of said pulsation to a period of time less than the time required for qlue

  said angular pulse at said second side of the crowd.

  20. A method of inserting a weft yarn into the shed of a weaving machine, characterized in that it comprises the following stages: the establishment of a confined area in the vicinity of a side said shed serving as a guide for a weft thread passing through said area; the generation of a pulsation of a gaseous fluid which

  passes through the said zone at a pre-

  selected and for a pre-termermeral period and which is directed to said crowd to thereby convey said fluid pulsation and said wire through

  said mob of said side of said foulc on an elongated side

  gng of said crowd; and - adjusting said pressure and said pulse duration to values such that said wire and said fluid pulsation arrive at the same distance from

  the crowd at predetermined speeds.

  21. The method of claim 20, wherein

  characterized in that it comprises the step of adjusting said pressure and said pulse duration, whereby said pulsation of fluid arrives at said remote state with a first velocity and said wire arrives at said remote with a speed lower than said first gear. 22. - Method of inserting a weft yarn (r) into the chatter crowd (S) of a loom, in which a nozzle (I) is placed in the vicinity of one side of the crowd, said nozzle converging to a minimum cross-sectional area and one end of a length of said wire is fed to the nozzle for insertion into the shed, characterized in that it comprises: (a) establishing a source of compressible fluid under a pressure exceeding that required for

  smother said nozzle and with a capacity of

  which substantially exceeds the possibility of flow of said nozzle; and (b) the flow rate of said pressurized fluid from said source with a throughput capacity exceeding the flow rate through the minimum nozzle area to produce in the minimum area.

  of the nozzle a state of suffocation and the continu-

  flow rate of said fluid in said nozzle for

  substantially support said state of suffocation during

  than the time required to establish said state, so that a pulsation

  of fluid under pressure at a speed of at least

  sonic is emitted by said nozzle, by driving the projection of said length of wire by said

nozzle in said crowd.

  23. The method of claim 22, wherein

  characterized in that prior to the feed rate of said fluid, the pressure of the source supplying it is set to a level within a range of pressures in which the time required for the wire to progress from a fixed distance therethrough of the crowd according to

  said pressure vary substantially in the same way

  portion than those needed for that pulsation of

  fluid progresses on the same distance.

  24. Process according to claim 22, characterized in that

  characterized in that the feed rate of said pressurized fluid is stopped before the arrival of the end

  driving wire at a fixed distance from said tufa.

  25. The method of claim 22, wherein

  controlled in that it includes the stage of the establishment

  a set of coaxial annular elements (41) made

  protruding between spaced pairs of adjacent warp threads, the elements of said assembly being arranged with axial alignment in a manner h defined a discontinuous tubular zone which transversely traverses the shed (S)

  inside and adapted to receive the impulse

  and the end of wire supplied by the nozzle and

  confine their trajectories inside the crowd.

  26. Process according to claim 22, characterized

  characterized in that said pulsation has a duration of at least about milliseconds and that the flow pressure

  is in the range of approximately 335 h 552 kPa

tive.

  27. The method of claim 22, wherein

  in that the amount of time necessary for

  said pressure produces a state of suffocation in the-

  said nozzle after the release of the flow of said fluid in the nozzle, is not greater than about S milliseconds and that said quenching state, once obtained, substantially exceeds said period of time in

a ratio of at least 2.

  28. A loom in which a weft yarn is inserted into a crowd of catenary yarns, characterized in that it comprises means (N, T) for defining a

  confined to the vicinity of the crowd, serving as guiding

  for a weft thread (F) passing through the

  said zone and means (Nt, U) for suddenly expelling a sustained pulsation of supersonic gaseous fluid from said zone and towards said crowd (S) so as to enter said weft yarn into at least one

a part of said crowd.

  29. The vessel according to claim 28,

  characterized in that it comprises guiding means (T) inside said shed for confining said wire

  on a preselected route during the passage of the

  said fluid pulsation and said wire in at least

said part of said crowd.

  30. A tier according to claim 28, characterized

  characterized in that it includes means (185a, 185b or 201a,

  201b) for adjusting the duration of said pulsation.

  31. The machine according to claim 28, carao-

  characterized in that said confined area includes a zone

  of convergence for the gaseous fluid.

  32. A craft according to claim 31, characterized

  characterized in that said fluid is expelled into a

  normal ambient atmosphere and includes means for

  said gaseous fluid in said convergence zone with a working pressure having, with respect to

  said ambient pressure, a ratio of less than 1.893: 1.

  33. The method of claim 4 or

  tier according to claim 31, characterized in that said confined zone includes, downstream of said zone of

* convergence, a zone of divergence.

  34. Method or mStier according to claim 33, characterized in that the ratio of the maximum area in the zone of divergence to the minimum area in the

convergence area is 1.176: 1.

  35. Method or loom according to claim 34, characterized in that the ratio of said ambient pressure to said working pressure is less than

0.2724 '

  36. The vessel of claim 30, wherein

  characterized in that said driving end of said wire is caused to pass by means of said pulsation through

  said crowd from one side of the crowd to a second

  side of the latter, and in that said means for resetting

  This limit limits the duration of said pulsation to a period of time less than the time required for the end of said wire to pass from said first side of the crowd.

audit second side of the crowd.

  37. The imager according to claim 30, characterized

2478 1 44

  whereby said fluid pulsation is passed through said shed from a first side thereof to a second side thereof and in that said setting means adjusts the duration of said pulse at a time period; not less than the m time necessary for that

  pulsation arrives at the second side of the crowd.

  38. A machine according to claim 33, characterized

  characterized in that it comprises means defining a zone for limiting the expansion of the fluid downstream of

said convergence zone.

  39. A mortar according to claim 29, characterized

  characterized in that said guiding means is open on

  its length at least partially to the atmosphere.

  40. Quarters according to claim 28, carao-

  characterized in that said guiding means defines a preselected diameter guiding zone during the passage of said wire through at least said portion of said tread, means for maintaining, between said confinement zone and said guiding zone, a gap such that said fluid enters the front guide zone

  that said fluid has expanded to a greater dimension

  greater than the diameter of said guide zone.

  41. A craft according to claim 28, characterized

  characterized in that said confined area includes a convergence zone through which said yarn passes and the loom includes means for protecting said yarn from contact with said fluid until said yarn reaches at least the downstream region, with respect to said

convergence zone.

  42. A craft according to claim 41, characterized

  characterized in that said confined area includes a zone of divergence downstream of said convergence zone and in that it includes means for protecting said wire from contact with said fluid until said wire reaches at least one of said downstream end of said divergence zone.

  43. A craft according to claim 41, carao-

  in that said means defining the zone con-

  terminated include means for forming an elongate zone for limiting the expansion of the fluid downstream of said

convergence zone.

  44. The craft of claim 42, characterized

  characterized in that said means defining the zone con-

  fine include ways to forge an elongated area

  for expanding the fluid downstream of said divergence zone.

  45. A craft in which a weft yarn is inserted into a chatty crowd, characterized in that it comprises means for defining a confined area in the vicinity of said shed, serving as a guide for a weft yarn passing through said area, means

  to generate a pulsation, of given duration, of a fluid

  gaseous passing through said zone and towards said shed to thereby convey the leading end of said weft yarn through said shed and means for limiting said yarn to a value less than the time required for said yarn end to

crosses said crowd.

  46. A machine in which a weft yarn is inserted in a chain shed, characterized in that it comprises means for defining a confined zone in the vicinity of a first cet6 of said shed, serving as a guide for a weft yarn passing through said

  zone, means for creating a pulsation of fluid

  zeux passing through said zone and towards said crowd to thereby convey the driving end of said weft yarn of said first one a second ceté of said crowd and means for limiting the duration of said pulsation hL a lapse of time less than the time

  necessary for the said pulsation to arrive at

xibme cte of the crowd.

  47. A machine in which a weft yarn is inserted in a warp shed, characterized in that it comprises means for defining a confined area in the vicinity of a side of said shed, serving as a guide for a passing weft yarn through said zone, means for generating a pulsation of gaseous fluid which passes through said area under a preselected pressure and for a predetermined duration and which is directed to said crowd to thereby convey said fluid pulsation and said wire through said crowd of said one side of said crowd to a remote side. of said crowd and means for adjusting said

  pressure and the said pulse duration at low values

  said wire and said pulsation of fluid arrive

  audit of the distant crowd at predetermined speeds.

  48. A nozzle comprising a nozzle located adjacent one side of the shed of the loom, said nozzle converging into a minimum cross-sectional area, and means for providing an end of a length of weft yarn to the nozzle for its insertion into the

  crowd, said domain being characterized in that

take:

  (a) means for establishing a source of a fluid

  pressure under a pressure greater than that

  necessary to quench said nozzle and with a feed capacity that substantially exceeds the flow rate of said nozzle; (b) cores for supplying said pressurized fluid from said source with a throughput capacity exceeding that of the actual de-bit through the minimum nozzle area, to produce in that minimum area. a state of suffocation; and (c) control means for continuing to admit said fluid into said nozzle so as to substantially support said quenching state for a period of time in excess of the time required for said quenching condition to be achieved, thereby that a pulsation of fluid under pre-pressure, having at least one supersonic velocity, is emitted by said nozzle, with consequent projection of said length of wire by said nozzle

in said crowd.

  49. A craft according to claim 48, characterized

  characterized in that it comprises means for adjusting the pressure of said fluid source to a level within a range of pressures, wherein the time required for the wire to progress from a distance

  fixed through the crowd according to said pressure

  in the same proportion as the time required for the pulsation of fluid

moves the same distance.

  50. The vessel according to claim 48, characterized

  it includes defenses in order to operate

  tioning said control means to arter ladm-is-

  said fluid under pressure with the arrival of the former

  leading end of the wire at a fixed distance from said nozzle.

  51. The craft of claim 48, characterized

  it includes a set of annulled elements

  coaxial wires (41) passing between spaced apart pairs of neighboring wires, the elements of said assembly being arranged with axial alignment for

  define a discontinuous tubular zone extending

  in the crowd and adapted to receive the

  pulsation and the extremity of wire of the nozzle and to

  end their traffic inside the crowd.

  52, Method for supplying wire to means of use which requires a finished length of wire, comprising the steps of: feeding said wire continuously from a wire feed source (P) to

  winding on a first surface (310) the advance

  said wire from said first surface to an outer

  tremity of a second surface for rewinding the wire on the second surface (320), the periodic actuation of said means of use to extract the wire of a

  opposite end of said second surface in accordance with

  forwarding said wire toward said first surface and said first surface toward an end of said

  second surface and the termination of wire extraction during

  that said finished length has been extracted from said end

  opposite of said second surface by said means

of use.

  53. The method of claim 52, characterized in that said first surface is a surface

of revolution.

  54. The method according to claim 53, characterized

  characterized in that it includes the stage of winding said

  film on said first surface according to a multiplicity

city of spaced turns.

  55. The method according to claim 53, characterized

  characterized in that said wire is continuously advanced

  at a substantially constant speed and in that it

  take the stage of preventing the advance of said thread from

  first surface to the second surface at a faster speed

  grmnde that said constant speed.

  56. A product according to claim 53, characterized

  in that it includes the stage of the application

  sitive of at least one of said turns of said wire against

said surface of revolution.

  57. The method according to claim 53, characterized

  characterized in that it includes the step of guiding said wire

  during his advance from said first surface to the

  said end of said second surface along an inclined surface (322) so as to arrange said

  turns on said second surface in a succession of

predetermined resolution.

  58. The method of claim 57, wherein

  characterized in that said inclined surface is disposed

  in the vicinity of said end of said second sur-

  face and is tilted down and forward towards

said extremity.

  59. The method of claim 58, wherein

  characterized in that said second surface is formed as

  a surface of revolving revolution and that said surface

  inclined face is also formed as the surface of

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  revolving revolution with said second surface.

  60. The method according to claim 59, characterized

  characterized in that said inclined surface is integral with

  said end of said second surface.

  61. The method of claim 52, wherein

  characterized in that said first surface is stationary

re.

  62. The method of claim 61, wherein

  têrisé in that it includes the stage of guiding said wire

  around said surface to wind on a multiple

tiplicity of thread turns.

  63. The method of claim 61, wherein

  teris6 in that it includes the stage of disposing of

  multiplicity of turns of wire on said first sur-

  face in spaced apart positions.

  64. Method according to claim 61, characterized

  characterized in that it includes the stage of preventing the advance, by said means of use, of said wire of said

  first surface at said second surface.

  65. The method of claim 52, wherein

  teris36 in that it includes the stage of producing a listening

  fluid (340), close to said second surface, to assist in winding said wire on said

second surface.

  66. The method of claim 65, wherein

  characterized in that it includes the steps of rotating said second surface and producing said fluid flow in the direction of rotation of said second surface.

  67. The method of claim 61, wherein

  the second surface is also stable.

  and the method includes wire guide stages around said surface for winding it

  top with a multiplicity of turns or turns.

  68. The method of claim 67, wherein

  defined in that it includes the stage of producing a

  flow of fluid in a direction

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  both turns to be applied against said surface.

  69. The method according to claim 67, wherein

  in that it includes the stage of advancing

  the yarn windings are as substantially block of said second surface in the direction of said means of use.

  70. The method of claim 52, wherein

  characterized in that it includes the step of advancing said wire to said second surface, in time relationship with the consumption of said wire by said

means of use.

  71. The method of claim 52, wherein

  in that it includes the stage of stopping the extrac-

  wire by engaging it in an intermediate location

  between said second surface and said means for

  sing. 72. Method of weaving, characterized in that

  a weft injection nozzle is established at the

  sinage of a crowd of chalne, including

  the following stages: the dosage, during each cy-

  weaving key, from a weft feed source for supplying the injection nozzle with a frame length corresponding substantially to the frame length to be inserted in the chain shed in this cycle and the provision of a pulsation of pressurized air through the injection nozzle to thereby project the length of metered wire into the chain shed, said pulsation containing sufficient pressure energy to propel one end of the weft length to the side opposite of the chain crowd, but not ending noticeably later than the arrival of

  said end of the frame length at said side oppo-

from the crowd.

  73. The method of claim 72, wherein

  characterized in that in the course of dosing the weft length is continuously and positively extracted from said feed source and collected in windings which progressively advance towards the injection nozzle and in that during its propulsion the weft is extracted

  of these windings by the nozzle at a sensible speed

  the highest rate at which the frame is extracted from the power source during the assay.

  74. Method according to claim 73, characterized

  in that said windings are arranged on

  an axis parallel to the axis of the nozzle.

  75. The method of claim 75, wherein

  characterized in that the frame etan, provided in con-

  continued by the collected windings is engaged frictionally in a Dune located upstream of these windings contrary to the forced advance of the windings in the axial direction, so that the extraction of the frame by the injection nozzle extracts all of these windings, downstream of said point, by pulling the frame essentially in straight ligae from this point

  forward in the chban crowd.

  76, Yrocéd6 according to claim 73, characterized

  characterized in that the driving ez-trmité of said metered weft frame reaches the opposite end of said crowd at the same time msme o. all of said collected bearings are extracted to this point

frictional engagement.

  77. Method of weaving, characterized in that

  a weft insertion nozzle is established in the vicinity of

  With one side of a chain crowd, the process includes the following stages: continuous extraction during

  each weaving cycle from a food source

  frame, of a measured lorzeur of sensitive frame-

  equal to the frame quantity to be consumed in this cycle and the supply of said measured frame length

  to a temporary storage area to be collected

  in an end portion of said cycle, removing the entire stored frame length from said storage area and injecting it with

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  said nozzle substantially within the crowd

  oak; and when said temporary frame length

  substantially atached is completely removed from said storage area, the termination of said removal and the collection of the next frame length for the cycle

following weaving.

  78. The method of claim 77, wherein

  characterized in that said frame length is extracted and fed to said temporary collection area at such a rate of flow that the end of said length reaches said temporary storage area substantially at the end of said cycle, the supply to said storage area continuing during the terminal part

  cycle, in which the frame length is removed.

  said nozzle, said removal occurring at a speed substantially greater than said speed

  flow, so as to obtain a virtually

  dump tantang of said length of said storage area despite continuous feeding thereof and upon completion of said substantially instantaneous state

  emptying, the termination of the said removal and the

  storage ration of the next frame length for

the next weaving cycle.

  79. The method according to claim 78, characterized

  characterized in that it includes means (330) disposed between said temporary storage area and said shed to pinch the weft length and actuating means of said clamping means to open these substantially at the beginning of said terminal part

  of the cycle and close them practically when the said

  stored frame is instantly emptied.

  80. The method according to claim 77, characterized

  characterized in that the leading end of said metered weft length reaching said opposite side of said mob substantially at the same time the stored weft length is substantially instantaneously emptied from said

storage area.

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  81. Apparatus for supplying thread to means

  of use requiring a finished length of wire,

  characterized in that it comprises: a first surface; means for continuously advancing said wire from a power source to engage a first surface; a second surface; continuously advancing said wire from said first surface to an end of a second surface to rewind the wire to the second surface, means periodically actuating said means for using to pull the wire from an opposite end of said second surface; surface while

  continuing the advance of said wire towards said first sur-

  face and from it to an end of said second surface and means for stopping the extraction of the wire when said finished length has been extracted from said opposite end of said second surface by said means of use without interrupting the advance wire to said first end of said second

area.

  82. Apparatus according to claim 81, characterized

  characterized in that said first surface is a surface

of revolution.

  83. Apparatus according to claim 82, characterized

  characterized in that it comprises means for winding said wire on said first surface in a multiplicity

spaced turns.

  84. Apparatus according to claim 82, characterized

  characterized in that said wire is continuously advanced from said feed to said first surface and from said first surface to an end of

  said second surface at a substantially constant speed

  aunt, and including means for biasing the advancement of said first surface ladits wire to said second

  surface, at a speed greater than the said speed

aunt.

  85. Apparatus according to claim 82, characterized

  characterized in that it comprises means for applying at least one of said turns of said wire against said

surface of revolution.

  86. Apparatus according to claim 82, characterized

  characterized in that it comprises an inclined surface for

  guide said thread during its advance of said first

  first surface at one end of said second surface for disposing said turns on said second surface

  following a predetermined succession.

  87. Apparatus according to claim 86, characterized

  characterized in that said inclined surface is disposed adjacent one end of said second surface and is inclined downwardly and forwardly from

said extremity.

  88. Apparatus according to claim 87, characterized

  characterized in that said second surface is a surface

  of revolution and that said inclined surface is likewise

  formed as a rotating surface of revolution with

said second surface.

  89. Apparatus according to claim 88,

* térrisé in that said inclined surface is secured

  said end of said surface.

  90. Apparatus according to claim 81, characterized

  characterized that said first surface is stationary.

  91. Apparatus according to claim 90, characterized

  characterized in that it comprises means for guiding said wire around said surface to wind on it a

multiplicity of turns of wire.

  92. Apparatus according to claim 90, carao-

  characterized in that said guide means have said plurality of turns of wire on said first

  surface in spaced apart positions.

  93. Apparatus according to claim 90, characterized

  controlled by including means that prevent the

  this, by said means of use, said wire of said

  first surface to said second surface.

  94. Apparatus according to claim 81, characterized

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  characterized in that it comprises means (340) for

  a fluid stream in the vicinity of said second surface to assist in winding said wire into said

first surface.

  95. Apparatus according to claim 94, characterized

  in so far as it includes means for making

  said second surface and means for producing said stream of fluid which create said stream in

  the direction of rotation of said second surface.

  96. Apparatus according to claim 90, characterized

  in that said second surface is stationary

  re and includes means for guiding the wire around said second suraoe to wind said wire sMr it

  with a multGiplicity of turns or turns.

  97. Apparatus according to claim 96, characterized

  in that it includes means (340) to

  to draw a stream of fluid flowing in a sena which urges the turns to be applied against the said surface.

  98. Apparatus according to claim 96, characterized

  characterized in that it comprises means for positively propelling all the yarn turns xialemet of said second surface towards said means

of use.

  99. Apparatus according to claim 81, characterized

  wherein said means for advancing said wire toward said second surface effectively act to advance it in time relationship with the

  consumption of said wire by said means of use.

  100. Apparatus according to claim 81, characterized

  characterized in that said means for stopping the extrac-

  wire are located in an intermediate location

  between said second surface and said moving means

  lisation. 101. IMSIétier including a weft insertion nozzle near a side of a crowd of cha / ne, characterized in that it comprises: means acting

2478 1 44

  during each weaving cycle for metering, from a frame feed source for d-bit in the injection nozzle, a frame length corresponding substantially to that inserted into the wobble crowd in this cycle, means for supplying a pressurized air pulse through the injection air nozzle so as to thereby project the measured weft length

  in the crowd of channels, ways to impress

  said pulsation a pressure energy sufficient to propel an end of the frame length to the opposite state of the chain mob and means for controlling the duration of the pulsating period to complete

  this practically after the arrival of the said

  mit6 of frame length auditing obeying opposite crowd.

  102. An elevator according to claim 101, characterized

  characterized in that said metering means comprises means for continuously and positively withdrawing said frame length from said source of power and for collecting it in windings which progressively advance towards the injection nozzle and in that the pulsation of said nozzle actually acts

  to extract said frame length from these windings

  at a speed substantially greater than the speed

  at which the weft is extracted from the food source

during the dosing.

  103. Mg * tier according to claim 102, charac-

  trisd- in that the means for collecting windings

  are arranged on an axis parallel to the axis of the nozzle.

  104. The ship according to claim 102, characterized

  characterized in that it comprises means for attacking said frame with friction at a point upstream of these windings, contrary to the forced advance of the

  windings in the axial direction, so that the former

  traction of the weft by the injection nozzle removes all of these windings downstream of said point, by tending the weft substantially in a straight line from

  from this point forward in the chalne crowd.

  Belon claim 102, which is

  in that the means for transmitting pressure

  and time adjustment are controlled in such a way that the

  leading edge of said measured weft length

  the opposite side of said crowd substantially at the same time as all of said collected windings

  is extracted Juaqu'atlit pqint friction commitment.

  106. Hoister including a weft injection nozzle located in the vicinity of a side of a chaine crowd, characterized in that it comprises: means

  acting during each weaving cycle to extract

  continuously, a frame feed source, a dosed frame length substantially equal to the amount of frame to be consumed in this cycle, means for continuously supplying said measured frame length to a storage area; temporary to be collected; means actuating said nozzle

  during a terminal part of the cycle to remove

  ver the entire stored frame length of the-

  said storage area and inject it substantially

  inside the chain crowd; and means

  when said frame length temporarily

  stored is completely removed from the said storage area.

  to complete the removal and institute the collection

  the following weft length for the fabric cycle

following sage.

  107. The sensor according to claim 106, characterized

  characterized in that said terminating means comprises

  pinch means disposed between said temporary storage area and said chalk shed to clamp the weft length and actuating means.

  said pinching means for opening said fingers

  when said frame length is complete-

  removed from said storage area.

  108.! A housing including a weft injection nozzle near a side of a crowd of chateaux, characterized in that it comprises: dosing means

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  acting during each weaving cycle to dose,

  from a frame power source to de-

  bit in the injection nozzle, a frame length

  substantially corresponding to the inserted frame length

  in the crowd of chatne in this cycle, means for providing a pulsation of air under pressure by the injection nozzle, so as to project the length of the weft metered across said crowd, and means

  to control said pulsation to complete the extrac-

  tion of said weft length dosed by said metering means, substantially coinciding with the arrival of one end of said weft length traversing said shed.