CA1040067A - Weft yarn storage device for jet weaving loom - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
A device for storing and detaining the weft yarn coming from the measuring drum of a jet weaving loom and for freely feeding the yarn to the intermittently operating nozzle of the loom. Said storage device is operated by compressed gas and comprises an elongated chamber freely open to atmosphere at its outer end and having its inner end supported by a head member and in communication with two separate passages of said head member;
namely: an inlet passage for the compressed gas and the yarn entering the chamber and an outlet passage for the yarn moving to the nozzle of the loom.
The yarn is pulled into the chamber by a high velocity flow of gas surrounding the same. The gas upon entering the chamber draws external air through an air opening of the chamber and the total gas mass moves slowly towards the open end of the chamber to maintain the yarn freely floating in the chamber.
The chamber has a relatively large cross-section whereby the yarn does not touch the chamber walls which remain clean. Yet the compressed gas flow required is very low. The high velocity gas flow immediately upon entering the inlet passage of the head member hits an inclined surface of the inlet passage to be diverted away from the yarn which moves along said inclined surface so that the high velocity gas flow will be in contact with the yarn over a minimum length to prevent damage thereto.

Description

ti'7 The present invention relates to a system for storing and detaining the weft thread in a jet weaving loom and, more particularly, to a storage device which receives the weft yarn at a constant rate from the measuring drum of the loom; stores it in a free flowing manner and without entanglement and allows it to be intermittently pulled out by the jet nozzle which propels a length of the yarn through the open harness shed of the loom.
Storage devices of known construction operate under vacuum, namely: the weft yarn issuing from the measuring drum is sucked through one end of an elongated chamber and exits therefrom to be directed to the nozzle.
Such known storing devices require frequent main-tenance, because the yarn constantly touches the walls of the elongated chamber and leaves thereon a deposit of fat sub-stances and other chemicals, which quickly builds up and Einally prevents the yarn from floating freely in the chamber and from being freely pulled out of the elongated chamber.
Therefore, the latter has to be cleaned very frequently.
The elongated chamber in such known devices must have a small cross-sectional area to limit the capacity of the vacuum pump to acceptable economical limits. In the event of yarn breakage, the latter is sucked by the pump and a filter on the pump line is required.
It is the general object of the invention to provide a storage device of the character described, which obviates the above-noted disadvantages and which, more particularly, uses a compressed gas generating system instead of the more expensive vacuum pumping system in which the elongated chamber is such of a cross-section that the looped yarn does not touch the chamber walls and does not soil the same; which positively feeds the yarn to the chamber, thereby producing a positive

-2-1~4~ '7 tension on the yarn coming from the measuring drum of the loom; and which uses a minimum of compressed gas flow to operate properly and practically without maintenance.
In one embodiment of the present invention, there is provided a weft yarn storage device suitable for use in a jet loom, the device comprising an elongated chamber, weft yarn inlet means located at one end of said chamber, weft yarn outlet means located at said one end of said chamber, the other end of said chamber being open, and means for supplying a pressurized fluid to said weft yarn inlet means coaxially with and surrounding a weft yarn passing through said weft yarn inlet means.
~n a further embodiment of the present invention, there is provided in a jet weaving loom, the improvement wherein the loom includes a weft yarn storage device, the device comprising an elongated chamber, weft yarn inlet means located at a first end of said chamber, weft yarn outlet means located at said first end of said elongated chamber, the other end of said chamber being open, means for supplying pressurized air to said weft yarn inlet means such that the pressurized air is coaxial with and surrounds a weft yarn passing through said inlet, and means located proximate said weft yarn inlet means for diverting the pressurized air from the yarn to cause an air current in the chamber directed towards a second end thereof, and means permitting the egress of said pressurized air from said chamber.
The foregoing and other objects of the invention will become more apparent during the following disclosure and by referring to the drawings, in which:-FIGURE 1 is a general perspective view showing part of a jet weaving loom fitted with the yarn storage device of the present invention and also showing, associated ~L~46~t7 therewith, the nozzle and liquid supply therefor and the weft yarn measuring system, FIGURE 2 is a diagram of the liquid supply system to the nozzle with the electrical controls therefor;
FIGURE 3 is a perspective view of the nozzle per se;
FIGURE 4 is a longitudinal section of the nozzle taken along line 4-4 of Figure 3;
FIGURE 5. is a partial longitudinal section of the filling storage device; and FIGURE 6 is a cross-section along line 6-6 of Figure 5.
In the drawings, like reference characters indicate like elements throughout.
The weft yarn 1 from a supply package 2 is trained on guide pulleys 3, 4 and then ~n to a measuring drum 5 and pulley 6, the drum 5 being operated by the loom drive at a speed adjusted to supply yarn l in a continuous manner at the rate required ~or the pick motion. The yarn l is then tempor-arily detained in a storage device 8 between each operation of a weft yarn propelling nozzle 7. Nozzle 7 throws a filling between the warp yarns 9 operated by the conventional har-nesses 27.
Nozzle 7 is illustrated in Figures 3 and 4. It includes a generally cylindrical body 10 having an axial bore defining from back to front a threaded portion 11, a main cylindrical bore portion 12, a frusto-conical portion 13 tapering from main cylindrical portion 12 and a terminal cylindrical bore portion 14, of reduced diameter, merging with the small base end of the frusto-conical bore portion 13. The terminal portion 14 openswithin a cylindrical, enlarged mouth 15.

As an example, frusto-conical portion 13 makes an angle of between 18 and 22 with the axis of the bore of the body and, '7 preferably, 20.
In this example, the length of the terminal cylin-drical bore portion 14 is a minimum of 1/4" and a maximum of

3/8".
~ threaded liquid inlet 16 opens laterally within main cylindrical portion 12.
The nozzle further includes a needle 17 adjustably screwed within the bore body 10. Needle 17 has an axial through bore 18 for the passage of the weft yarn from back to front in accordance with arrows 19. The inlet end of the yarn passage 18 is flared, as shown at 20, to minimize friction on the yarn.
The needle includes a main body 21 having external threads for engaging with body threads 11. Said main portion has a rear ~lange 22 ~or manually adjusting the axial position of the needle 17 in body 10.
The main portion 21 is ~ollowed by a main cylindrical portion 23 opposite main bore portion 12 to define therewith an annular cylindrical space 24.
~eedle cylindrical portion 23 extends forwardly opposite frusto-conical body portion 13 and merges with a needle frusto-conical portion 25 tapering forwardly to be preceded by a needle terminal 26, which extends opposite body bore portion 14 and protrudes within the mouth 15. Needle terminal portion 26 is slightly tapered forwardly, the taper being about 4.
The annular space between needle portion 26 and body bore portion 14 is between 4 and 8 mills in width. The frusto-conical portion 25 of the needle tapers at a slightly smaller angle than the frusto-conical portion 13 of the body, so as to define an annular converging passage decreasing in width slightly in the forward direction.

4~ 7 It will be understood that by adjusting the axial position of the needle, the annular passage between frusto-conical portions 13 and 25 will decrease or increase in width accordingly, thus making an adjustment of the flow of fluid for a given fluid pressure.
It is noted that the nozzle defines at least a two-stage taper, namely needle surfaces 25 and 26 and coopera-ting body bore surfaces 13 and 14 for the formation of the liquid jet having maximum energy content for a given liquid supply pressure. Yet the nozzle is simple and inexpensive to manufacture.
Practical operation of this nozzle has shown that a weft thread can be effectively propelled a distance of up to 72" through the shed of arrayed warp yarn in a shuttleless loom with a liquid supply pressure of about 45 pounds and a quantity of water of less than 3 centimeter cube ejected up to a maximum of 50 milliseconds, the yarn used being a 150 deniers acetate yarn. This compares with conventional jets in which a liquid pre~sure of 125 pounds per square inch is used and a minimum quantity of 4 to 6 centimeter cube of water is neces-sary to propel the yarn the above-noted distance.
Referring to Figure 1, the inlet 16 of the nozzle 7 is directly connected to the outlet of an adjacent remote-controlled valve, for instance an electro-magnetic valve, indicated at 30, this valve being of conventional type and being electrically connected (see also Figure 2) to the output of an electric pulsator 32 which is arranged to produce an electric pulse to operate electro valve 30 for an adjustable duration of, say, between 0 and 50 milliseconds, the duration being controlled by a knob 33.
The input of the pulsator 32 is controlled either by a manual button switch 31 or by a micro switch 33, the lever 34 of which rides on a cam 35 directly connected to a rotatable shaft 35' of the loom, so that the switch 33 will open and close in synchronism with the beating or harness motion of the loom. Thus, each time the shed of the warp yarns is open, the electric circuit to the pulsator is closed and the latter opens the electro valve 30 for the adjusted number of milliseconds, so that the liquid jet will propel the yarn from the passage 18 of the needle 17.
The electric pulsator is preferably provided with a variable time delay circuit adjustable by a manual knob 33'.
This delay system retards in an adjustable manner the time the electric pulse or signal is sent to electro-magnetic valve 30 from the time cam-operated switch 33 is closed. Thus, one can finely control the synchronization of the nozzle operation with the harness motion and the beating motion.
Instead of a cam-operated switch 33, one could use any other transducer such as a photocell responsive to a light beam reflected off a surface portion of the loom shaft 35' or magnetic transducer responsive to the rotation of loom shaft 35'. Thus, wear of mechanical parts is eliminated.
The electro-magnetic valve 30 can be replaced by a pneumatic valve and the pulsator 32 replaced by a pulsator which is electrically operated to generate a signal in the form of a pulse of pressurized gas to actuate the pneumatic valve.
The liquid jet issuing -from the nozzle is tubular in form and adheres to the weft yarn, to effectively propel the same.
The water supply for the inlet of the valve 30 is indicated in Figure 2 by a pipe 26, which is series-connected with a bleedirg valve 37 to remove the air in the water, in turn preceded by an accumulator 38, of known type, to eliminate 1~34¢~
water hammer, in turn preceded by a liquid pressure regulating valve 39, in turn preceded by a liquid filter 40 and a shut-off valve 41, the inlet of which can be connected to the regular public works water supply. Obviously, valve 30 can be cor~ec-ted to any other suitable low pressure liquid supply.
Before the weft yarn 1 enters the nozzle 7 and upon leaving the constant speed measuring drum 5, it is detained or stored in a storage tube 8. This storage tube is shown in Figures 1, 5 and 6. Each storage tube comprises a head member consisting of blocks 42 and 47. Block 42 is secured to the frame 43 of the machine. Block 42 has a yarn passage 44, shown in Figure 5, with a restricted outlet opening 45 in substantial alignment with the yarn passage 18 of the nozzle 7, the latter being also mounted together with the solenoid valve 30 on the loom frame ~3~
The rear end o block 42 is inserted within an eccentric bore 46 o cylindrical block member 47, which is thus supported by block 42 and in turn supports in cantilevered manner an elongated chamber of tube 48 telescopically fitted about block 47 and retained thereon by a collar 49.
Tube 48 is open at its outer end 50 and can be made of transparent plastic material to enable viewing of the weft yarn 1 therein.
Block 47 has an inlet passage Sl offset from bore 46 and generally parallel thereto, said passage being generally cylindrical, except for a transversely flat surface 52, which defines, longitudinally of the inlet passage, an upwardly inclined portion 53, followed by a downwardly inclined portion 54, the two portions merging in a smooth manner by means of an intermediate convex portion 55.
A disc 56 is inserted within tube 48 and applied against the inside face of block 47. This disc 56 has circular openings 57 and 58 in register with the inlet passage 51 and with the block passage 44, respectively.
An elbow nipple 59 is threaded within block 47 at the outer face thereof and its outlet passage 60 is parallel to block passage 49 and is directed against the upwardly inclined portion 53 and the convex portion 55 of the surface 52 of the inlet passage 51.
The inlet 61 of elbow 59 is connected to a supply of compressed air by tubing 62 (see Fig. 1). A small diameter tube 63 extends within the outlet passage 60 of elbow 59, being concentric therewith, said small tube extending through the wall of the elbow 59. Tube 48 has an air inlet opening 67 adjacent block 47.
Weft yarn 1 coming from the measuring drum 5 moves through a guiding eyelet 64 aligned with small tube 63 and then passes through said tube 63 into inlet passage 51, through disc opening 57 and then freely into the main tube 48. The yarn makes a floating loop in the tube 48 and returns through disc opening 58; block passage 44; restricted block outlet 45 to enter the nozzle 7. An electrically-operated gripper 65 is mounted at the outlet of block 42 in register with outlet 45 of said block.
Compressed air issuing as an annulus from elbow 60 surrounds yarn 1 and positively propels the latter into the inlet passage 51. The air immediately hits the upwardly inclined surface portion 53 and is thus immediately directed against the opposite surface of the inlet passage 51, as indicated by arrows 66. The air is thus diverted away from yarn. The compressed air then enters the tube 48 and there is produced a slow-moving air current in tube 48 directed towards the open end 50, where the air freely escapes. This air current sucks in fresh air through air opening 67. This slow-moving air current, together with supplemental air enter-ing through opening 67, is sufficient to keep the thread 1 freely floating in the tube 48 without touching the wall of the latter. Air opening 67 also prevents the production of negative gas pressure at the entrance of block passage 44.
Because the high velocity pressurized air issuing from nipple 59 is immediately diverted upwardly by the upwardly inclined surface portion 53, this high velocity air is in contact with the yarn 1 over a very restricted length of the latter, whereby the air cannot in any way damage the yarn 1. Damage would result if the air under high velocity was allowad to be in contact with the yarn over a substantial length thereof.
The yarn within tube 48 has been found to float freely without yarn entanglement. The yarn is freely fed to the nozzle 7 upon operation of the same. Once the required length of a yarn has been propelled by the nozzle, the electri-cally-operated gripper 64 operates to grip the yarn at the block outlet 45. The gripper releases the yarn after stopping of the nozzle operation.
Referring to Figure 1, hand lever 68 is conventional and serves to start and stop the loom.
The nozzle system of the invention can be manually operated for testing the loom: a knob 69 on the measuring drum

5 is pulled to declutch the;latter and the drum is manually rotated to the required length as seen in tube 48. Then pul-sator 32 is manually actuated by push button switch 31 to produce one pulse and effect one filling.
It is known that the yarns used in weaving are coated with chemicals and/or oily substances which cause a build-up on the inner surfaces of the storage tube if the yarn is allowed to touch the latter. This happens in conventional 16'7 vacuum operated storage tubes, because of their small cross-sectional size necessitated by the use of vacuum. Thus, these vacuum tubes must be cleaned frequently. Also, it is less expensive to produce compressed gas than to use a vacuum pump.
Finally, the use of a gas jet nozzle, such as the nozzle constituted by elbow nipple 59, positively pulls the yarn 1 from the measuring drum 5 and, therefore, maintains constant tension on that portion of the yarn preventing its slippage on the drum 5~

Claims (7)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A weft yarn storage device suitable for use in a jet loom, the device comprising an elongated chamber, weft yarn inlet means located at one end of said chamber, weft yarn out-let means located at said one end of said chamber, the other end of said chamber being open, and means for supplying a pressurized fluid to said weft yarn inlet means coaxially with and surrounding a weft yarn passing through said weft yarn inlet means.

2. The device of claim 1 including a deflecting surface within said chamber, said deflecting surface being proximate said weft yarn inlet means and being located to deflect the pressurized fluid from the weft yarn.

3. The device of claim 2 further including an air opening open to the atmosphere within said chamber to permit air into said chamber under the action of an air current produced by said pressurized fluid.

4. The device of claim 1, 2 or 3, wherein said deflecting surface comprises an upwardly inclined surface adjacent said weft yarn inlet means, followed by an intermediate convex sur-face portion, in turn followed by a downwardly inclined surface portion, all three surface portions merging smoothly with one another.

5. In a jet weaving loom, the improvement wherein the loom includes a weft yarn storage device, the device comprising an elongated chamber, weft yarn inlet means located at a first end of said chamber, weft yarn outlet means located at said first end of said elongated chamber, the other end of said chamber being open, means for supplying pressurized air to said weft yarn inlet means such that the pressurized air is coaxial with and surrounds a weft yarn passing through said inlet, and means located proximate said weft yarn inlet means for diverting the pressurized air from the yarn to cause an air current in the chamber directed towards a second end thereof, and means per-mitting the egress of said pressurized air from said chamber.

6. The improvement of claim 5 wherein said chamber includes an air opening to the atmosphere adjacent a communica-tion of said chamber with said weft yarn outlet means such that air is drawn into said chamber under the action of the air current produced by said pressurized air.

7. The improvement of claim 6 wherein said means for diverting said pressurized air comprises an upwardly inclined surface adjacent said weft yarn inlet means, followed by an intermediate convex surface, in turn followed by a downwardly inclined surface, all three surfaces smoothly merging with one another.