Classifications

• • D—TEXTILES; PAPER
  • D03—WEAVING
  • D03D—WOVEN FABRICS; METHODS OF WEAVING; LOOMS
  • D03D49/00—Details or constructional features not specially adapted for looms of a particular type
  • D03D49/24—Mechanisms for inserting shuttle in shed
  • D03D49/42—Mechanisms for inserting shuttle in shed whereby the shuttle is propelled by liquid or gas pressure
• • D—TEXTILES; PAPER
  • D03—WEAVING
  • D03J—AUXILIARY WEAVING APPARATUS; WEAVERS' TOOLS; SHUTTLES
  • D03J5/00—Shuttles
  • D03J5/06—Dummy shuttles; Gripper shuttles

Definitions

• Carrier for inserting a weft yarn into the shed of a weaving device.
• the invention relates to a carrier according to the preamble of claim 1 for inserting a weft yarn into the shed of a weaving device via insertion means arranged on one side or on both sides of the shed.
• a carrier as referred to in the introduction above is described in Dutch Patent Application No. 73/09850, for example, and more in particular in US Patent No. 4,046,174.
• a weft yarn from a supply bobbin is connected to the known carrier, also called shuttle, after which the carrier is launched as a projectile by the insertion means disposed on either side of the shed, using a medium under pressure, for example pressurized air, and carried through the shed via guides arranged in the shed.
• a drawback of these known devices, and in particular the shuttle as disclosed in US-A1-4,046,174, is the fact that all the energy required for moving the voluminous and thus heavy carrier through the shed must be imparted to the carrier at the beginning of the movement, i.e. at the location of the insertion means.
• a large amount of energy has be supplied to the carrier at the beginning of its movement, which means a very high initial velocity, resulting in high peak tensions in the weft yarn to be transported.
• the carrier needs to have a fairly large inert mass.
• auxiliary blowers are disposed in the shed, which auxiliary blowers are provided with outflow openings for the medium under pressure, which impacts on an impact surface of the carrier to be guided during operation so as to assist in the movement of the projectile through the shed.
• Dutch Patent Application No. 1023943 (not pre-published) furthermore proposes the use of a carrier that surrounds a weft yarn in the form of a clew, which clew extends the length of the shed upon insertion into the shed.
• the dimensions of said carrier correspond to the dimensions of the clew, and the weight of the carrier is of the same order as that of the clew to be inserted.
• the low weight and the limited dimensions of the carrier used in NL-1023943 obviate the need to use complex and robust means for inserting and decelerating the carrier, so that an insertion mechanism of simple construction will suffice.
• the movement of the known carriers through the shed is adversely affected by the air jet pulse being delivered to the carrier by the insertion means of the weaving device.
• the aerodynamic behaviour of the carrier is adversely affected by the air jet pulse, to such an extent that the movement of the carrier through the shed takes place in a rectilinear, not very stable manner. This leads to weaving faults caused by the fact that the movement through the shed and the insertion of the weft yarn do not take place (completely).
• the object of the invention to provide a carrier for inserting a weft yarn into the shed of a weaving device, which can be characterized by an improved aerodynamic behaviour and consequently a more stable movement through the shed during the "shot", resulting in a strongly improved weaving process.
• the air transmitting area of the pull-out opening is smaller than or equal to the air transmitting area of the means in the circumferential surface of the carrier that advance the transmission of air.
• the presence of the air transmitting means furthermore assists in the filling of the carrier with a certain length of weft yarn, as well as in the launching of the carrier into the shed by means of an air pulse.
• the air pulse being delivered exerts a large (temporary) force/pressure on the carrier, which force needs to be quickly diverted in order to prevent damage to the carrier.
• the quick diversion of the forces and pressure differences across the carrier through the air transmitting means prevents possible deformation of the carrier, which would result in the carrier jamming or being blocked during the acceleration phase in the weaving device.
• the carrier is provided with openings.
• the openings may be in the form of perforations, cuts of slots.
• the carrier is made of an air- permeable material, in particular a porous material, more in particular a gauze-like or filter cloth material.
• a carrier having air transmitting characteristics is obtained, as a result of which the air jet pulse delivered by the insertion means will have a much less adverse effect on the movement or "flight" of the carrier through the shed than is currently the case.
• the carrier according to the invention exhibits an aerodynamic behaviour that has a positive effect on the weaving process. The same line of reasoning applies to a fixedly disposed carrier from which the weft yarn is pulled.
• the carrier is made of a plastic material. This makes it possible to manufacture the carrier in large numbers as a light, inexpensive unit, which is furthermore reusable.
• the carrier is cylindrical in shape so as to achieve a stable movement through the shed under the influence of the air jet pulse delivered by the insertion means on the one hand and an adequate retainment of the weft yarn and a smooth extension thereof from the carrier on the other hand. Also other sectional shapes are conceivable, however, in particular polygonal (triangular, square, etc) shapes.
• the internal diameter of the carrier is so small, e.g. 6 mm or less, that the weft yarn's own bending resistance causes the windings to be supported against the inner wall of the carrier.
• the weft yarn is retained within the carrier in such a manner that the weft yarn will not get tangled upon being extended. This has a positive effect on the efficiency and the weaving result.
• the carrier is narrowed at the location of the pull-out opening in order to prevent the weft yarn that is surrounded by the carrier from being pulled from the carrier as a whole in one go during movement through the shed. The packed weft yarn is thus retained within the carrier and the weft yarn is extended over its entire length during movement through the shed.
• the known weaving device comprises a lay 1 and is provided with means 2 for forming a shed 3 of warp yarns 4, which warp yarns 4 come from warp yarn supply bobbins 5.
• a large number of dents 6, together forming the so-called "reed”, are arranged on the lay 1, which dents can move between the warp yarns 4.
• a number of guides 7 are furthermore arranged on the lay 1 for guiding a projectile 8 from one side of the shed 3 to the other side thereof.
• the projectile 8 is present in an insertion station 9 disposed on the left-hand side of the shed 3, whilst a braking station 10 is disposed at the other side of the shed 3.
• a weft yarn 11 from a supply bobbin 12 can be connected to the projectile 8 in a known manner.
• a considerable amount of impulse energy is imparted to the projectile 8 by means of a medium under pressure, for example compressed air or water.
• the projectile 8 undergoes an acceleration and is moved or "shot" through the shed 3 at a high velocity, carrying along the weft yarn 11.
• the projectile 8 is also called the shuttle, therefore.
• the projectile 8 that moves through the shed 3 at a high velocity must be decelerated on the other side of the shed 3 (on the right in figure 1).
• a braking station 10 is disposed directly beside the shed 3, which station 10 intercepts and decelerates the projectile as it leaves the shed 3.
• the projectile 8 can be moved ("shot") from the right-hand side to the left-hand side of the shed 3 at a high velocity by an insertion station 9' (not s commonlyhown) arranged analogously to the insertion station 9, which is disposed on the right- hand side of the shed 3.
• a braking station 10' (not shown) is furthermore disposed at the location of the insertion station 9 for intercepting and decelerating a projectile 8 moving from the right-hand side to the left- hand side of the shed 3.
• the large inert mass of the projectile 8 and the frequently considerable width L of the shed 3 require that the projectile 8 be moved through the shed 3 at a relatively high velocity.
• the forces set up in the weft yarn 11 as a result of the acceleration and the velocity of the carrier lead to undesirable peak tensions, which may cause the yarn to break.
• the projectile 8 moving through the shed at a high velocity must be intercepted at the end of the shed and be decelerated by a separate braking station 10 (10').
• the carrier- 20 is made up of an elongated, preferably cylindrical element having a circumferential surface 21 with a substantially closed front end 20a (seen in the direction of movement through the shed) and an open rear end 20b (likewise seen in the direction of movement through the shed).
• the weft yarn 22 is present in the hollow cylindrical carrier 20 in the form of a packed clew, so that the carrier 20 at least partially surrounds the packed clew of weft yarn 22.
• An end portion 23 of the weft yarn 22 projects from the carrier 20 via the open rear end 20b thereof.
• the yarn end 23 is held by the insertion means (see figure 1), whilst the carrier 20 is "shot” into the shed, for example by means of a medium under pressure such as air or water.
• the weft yarn 22 is pulled from the open carrier end 20b during the movement of the carrier through the shed, causing it to extend over the entire width of the shed.
• the weaving device can thus be constructed with lighter components that allow a higher speed of operation, i.e. high-speed weaving. More in particular, when using a carrier according to the invention, the forces are exerted on the carrier and on the packed clew of yarn 22 rather than on the yarn itself. Now that a clew of yarn rather than separate yarns is inserted into the shed, peak tensions in the yarn are prevented, since it is the clew of yarn (instead of a separate yarn) that is subjected to the acceleration forces that are exerted by the insertion means upon insertion of the carrier.
• the carrier as shown in figures 3b-3d are provided with means that advance the transmission of air from the air pulse being delivered by the insertion means.
• the means that advance the transmission of air consist of a large number of openings or perforations 24 formed in the circumferential surface 21 of the carrier 20.
• the air pulse delivered by the insertion means with ever weft stroke, which is intercepted by the carrier 20, can thus readily escape via said openings or perforations 24, resulting in a less erratic but more stable and more gradual "flight" during the movement through the shed.
• the aerodynamic behaviour of the carrier 20 according to the invention is strongly improved.
• the openings that advance the transmission of air by the carrier 20 consist of several cuts or slots 25 formed in the circumferential surface 21. Said cuts may be V-shaped.
• the openings may be configured to open at a specific pressure difference across the carrier wall so as to equalise said present difference and pull the weft yarn from the carrier in a trouble- free manner.
• the carrier is made of an air-permeable or porous material 26.
• a filter cloth or gauze-like material is a very suitable material, through which the air flow that enters via the rear end 20b can easily escape. More in particular, the openings that advance the transmission of air by the carrier 20 are uniformly distributed over the circumferential surface 21 of the carrier 20.
• FIG. 4 shows another embodiment of the carrier according ' to the invention, in which the carrier is provided with a narrowed portion or constriction 26 near the pull-out opening 20b.
• Said narrowed portion or constriction 26 functions to ensure that the clew of yarn 22 is fully extended into a weft yarn 22 via the loose end 23 during the movement of the carrier 20 through the shed instead of being pulled out of the carrier in the form of a clew. This construction prevents the occurrence of further weaving faults.
• the aerodynamic behaviour of the carrier is significantly improved if, according to the invention, the air transmitting area X of the pull-out opening 20b (which may or may not be constricted) is smaller than or equal to the air transmitting area Y of the means 24-25-26 in the circumferential surface 21 of the carrier 20 that function to advance the transmission of air.
• the carrier is according to the invention provided with one or more projecting edges 27 formed on the carrier 20 in the longitudinal direction thereof. Said projecting edges 27 function as supporting fins or flaps that support the carrier during its movement through the shed, thus enabling a more rectilinear and more stable movement through the shed.

Landscapes

• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Looms (AREA)
• Auxiliary Weaving Apparatuses, Weavers' Tools, And Shuttles (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=34965611

Family Applications (1)

Country Status (5)

Family Cites Families (5)

• 2004
  • 2004-05-19 NL NL1026238A patent/NL1026238C2/nl active Search and Examination
• 2005
  • 2005-04-25 WO PCT/NL2005/000305 patent/WO2005111286A1/en active Application Filing
  • 2005-04-25 CN CNA2005800202623A patent/CN1969070A/zh active Pending
  • 2005-04-25 JP JP2007527069A patent/JP2007538171A/ja active Pending
  • 2005-04-25 EP EP05736376A patent/EP1756342A1/en not_active Withdrawn

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events