US3734143A

US3734143A - Measuring and length determining means for weft yarn in shuttleless looms

Info

Publication number: US3734143A
Application number: US00079478A
Authority: US
Inventors: V Svaty
Original assignee: Elitex Zavody Textilniho
Current assignee: Elitex Zavody Textilniho; Elitex
Priority date: 1969-10-10
Filing date: 1970-10-09
Publication date: 1973-05-22
Anticipated expiration: 1990-05-22
Also published as: DE2049373A1; FR2064236B1; GB1322519A; FR2064236A1

Abstract

A shuttleless loom having a pneumatic delivery means and apparatus for measuring and determining the length of weft yarn fed thereto. The apparatus is adapted to pull a length of yarn from a supply, in cyclic action and hold the same under tension while being fed to the pneumatic means.

Description

United States Patent 1191 Svaty 1 May 22, 1973 1 MEASURING AND LENGTH References C d DETERMINING MEANS FOR WEFT UNITED STATES PATENTS LE L S YARN IN F T SS M 3,626,990 12/1971 Linka ..139/122 R Inventor: Vladrmll' y, hlberec, 2,637,349 /1953 Dunham ..139/127 1? Czechoslovakla 3,229,725 l/1966 Saito ......139/127 P Assigneez Elitex, z y textilniho strojiren MIZUUO Bi 8.1. P

stric generalnl reditelstvl, Liberac, FOREIGN PATENTS OR APPLICATIONS Czechoslovakia 583,830 /1958 Italy ..139/127 P [22] Filed: Oct. 9, 1970 [21] Appl No; 79 478 Primary ExaminerHenry S. Jaudon AttorneyRichard Low and Murray Schaffer Foreign Application Priority Data [57] ABSTRACT Oct. 10, 1969 Czechoslovakia ..6777/69 A h l less m having a pneumatic delivery means and apparatus for measuring and determining the [52] U.S. CI ..139/127 P length of weft yarn fed thereto. The apparatus is [51] Int. Cl. ..D03d 47/30,]303d 47/34 adapted to pull a length of yarn' from a supply, in

of Search cyclic action and the ame under tension Sal/RUE of mow/M being fed to the pneumatic means.

8 Claims, 5 Drawing Figures PATENTE W22 I973 SHEET 1 OF 2 INVENTOR WAD/M1 R SVA TX 71/ ORNEYU J MEASURING AND LENGTH DETERMINING MEANS FOR WEFT YARN IN SHUTTLELESS LOOMS BACKGROUND OF INVENTION The present invention relates to apparatus for fabrics and in particular to a shuttleless loom.

While shuttleless weaving looms, in which the weft yarn is thrown by a jet of high pressure air between the opened warp yarn system of a fabric shed, have become known they have many disadvantages. Such machines have limited width, low speed, poor efficiency, and little versatility. Attempts to overcome these disadvantages have been tried. For example looms with double sheds fed by one inserting device have been suggested. It was necessary however to provide this machine with gripper rods, pivotable needles, or other means to grasp the weft yarn and insert it alternatingly in the form of a loop into the opposite sheds.

In any event, the known looms are unsuitable for the production of weaving apparel since they require the insertion of a double weft and are not adaptable to the production of multicolor or mixed weft feeding as would be necessary for the production of such material as silk and cotton.

When the loom is provided with a double shed and gripper means, the mechanism for mounting and operating the gripper means is large and takes up a large space between the sheds. Consequently, the loom becomes unnecessarily large while the sheds become unnecessarily small. It has been found that the efficiency speed and size of these known machines are in large measure limited by the pneumatic delivery or insertion system and the system for premeasured defined lengths of yarn for insertion as weft in the warpyarn systems.

It is accordingly the object of the present invention to provide an improved shuttleless loom having increased efficiency, speed, and versatility.

It is the object of the present invention to provide an improved shuttleless weaving loom capable of fabrics of large widths.

It is another object of the present invention to provide a shuttleless loom in which weft yarns may be mixed and of different color.

It is an object of the present invention to provide an improved pneumatic weft yarn insertion device for a shuttleless loom.

It is an object of the present invention to provide an improved system and apparatus for measuring and feeding defined lengths of yarn to the pneumatic insertion device of a shuttleless loom.

It is another object of the present invention to provide improved means for premeasuring and feeding yarn to a double nozzle pneumatic delivery system of a shuttleless loom.

It is another object to increase the speed and efficiency of measuring and feeding weft yarn.

These objects, others and numerous advantages will be found in the following disclosure.

In a copending application Ser. No. 79,035 filed on even date herewith, in the name of the same inventor, there is disclosed and claimed a novel pneumatic insertion of a delivery mechanism which may be used in conjunction with the present invention.

SUMMARY OF INVENTION According to the present invention there is provided a shuttleless loom having pneumatic means for delivering yarn to a fabric shed comprising apparatus for measuring and determining the length of the yarn. The apparatus comprises selectively operable withdrawing means interposed between a supply and the delivery means and selectively operable brake means located between the supply and the withdrawal means. Control means are provided to sequentially operate the brake and withdrawal means for a predetermined time to pull a defined length of yarn from the supply.

The withdrawal means may comprise a pair of opposed rollers, however, it preferably comprises a pulley held between the ends of a cable which is held at one end by a winch and at the other by a yieldably resilient member. The yarn passes over the pulley which by being reciprocally pulled withdraws a defined length of yarn from the supply.

BRIEF DESCRIPTION OF THE DRAWINGS In the following disclosure reference is made to the accompanying drawings wherein:

FIG. 1, is a plan view, partially in section and partially schematic, showing a loom embodying the insertion device and measuring system of the present inven tion;

FIG. 2, is view similar to FIG. 1 showing another form of the invention;

FIG. 3, is an enlarged sectional view showing the position of the pneumatic insertion device of the present invention with regard to the warp system and beat reed;

FIG. 4, is a vertical section through the insertion device of the present invention; and

FIG. 5, is an enlarged plan view of the details of the control means for the insertion device.

DESCRIPTION OF INVENTION Before turning to the disclosure of the present invention it is to be understood that the drawings and description give only those details of a loom which are new and which are necessary for a full and complete understanding of the present invention. It will be obvious that certain well known details are omitted. Reference to conventional looms, well known texts and literature can be made by those skilled in this art to supplement the present disclosure, if that is necessary.

As seen in FIG. 1 the loom is provided with a common weft feeding and inserting device 1 located transversely between two opposed warp or shed systems. The inserting device 1 is a pneumatic system which as seen in FIGS. 4 and 5 comprises a reversible nozzle assembly from which extends a pair of

hollow cones

2,2 through the

respective orifices

3,3 of which

pass weft yarns

4,4. The yarns are fed through a central opening at the top of the nozzles assembly by means to be described later.

The

cones

2,2 of the nozzle assembly are mounted on a carrier body 5, journalled for rotation upon a bearing 6 which is itself mounted by suitable screw fasteners to an arm 7. The arm 7 extends cantilevered from and is adjustably secured to a longitudinally extending breast beam 8. The arm 7 is provided with a channel 9 extending centrally to a point beneath a duct 10 which itself extends through the center of both the bearing 6 and carrier 5. A transeverse bore 11 is formed within the carrier 5, beneath the

cones

2, 2, which communicating with the duct 10 opens outwardly in the direction of the

orifices

3,3. Surrounding each of the

cones

2 and 2 and the respective ends of the bore 11 are conical funnel caps 12 and 12 respectively adapted to condense and direct the air about the cones outwardly in a horizontal column from the

orifice

3,3.

Air is supplied from the source to maintain a volume within the nozzle assembly, to hold the end of the

yarn

4, 4 in the

orifice

3,3, and at selected time supplied as an impulse jet of high pressure to force and carry the yarn outwardly into the respective sheds. The supply of the picking fluid, as seen in FIG. 3, in this particular case the pressure air, to the inserting device 1 is directed by means of a feed line 53 and a compressor 54 driven by an electric motor 55, there being a valve 56 disposed in the line 53, which is controlled by a solenoid 57. The solenoid 57 is connected (FIG. by means of conductors 58 with a switch 59 and a source of electric current 60.

A wheel gear 13 is secured about the lower end of the carrier and is engaged by a corresponding segment ratchet 14. The segment ratchet 14 is fixed at the end of a lever 15 pivoted at its other end 15 on the arm 7. The lever 15 is operatively positioned by the core of a solenoid control device 16 and a compression spring 17. The solenoid 16 is a conventional electromagnetic device capable of retracting or permitting extension of the core 16 on the application of an electric current through the coil. Solenoid 16 (FIG. 5) is connected by means of conductors 61 with another switch 62 and also with a source 63 of electric current. Associated with the switches 59 and 62 are control cams 64 and 65 mounted on a common shaft, together with the cam 39. Mounted on the same shaft is still a cam 66 controlling a switch 67 which by means of conductors 68 closes the electric circuit for solenoid 69 of the brakes 46, 46' according to FIG. 1, or for solenoid 37, the latter controlling the bell crank 36 which supports the feed roller 35, according to FIG. 2. The source of current switch, or relay means, is conventional. The swing of lever 15 and consequently of ratchet 14 is limited by the stop pins 18 and 19 which are set so as to enable full movement of the ratchet 14 to rotate the nozzle assembly by 180.

As seen in FIG. 3 the outer or free end 20 of the arm 7 extends over the batten 21 of the loom. The batten 21 is mounted on the upper end of a lever arm or sword 22, pivoted to the frame of loom at its other end 23. The batten 21 carries a divided

reed

24, 24 to beat up the

weft yarns

4,4 as they are laid into the fabrics sheds 25, 25 produced on the loom to either side of the weft feed assembly. The

reed

24,24 is adjustably mounted to the batten 21. As seen in FIG. 1 the arm 7 furthermore carries

temples

26,26 for holding the selvedges of the advancing

fabrics

25, 25. As seen in the Figures the arm 7 is arranged symmetrically between two sheds formed from

warp

27, 27 systems forming the

fabrics

25, 25. In the event fabrics of uneven width are desired, it is only necessary to move the arm to the right or left a corresponding distance.

An elongated channel housing member 28 is mounted above the length of the breast beam 8. The housing defines an inner space 29 and is covered by a lid 30. As seen in FIGS. 1 and 2 the channel member 28 houses within the space 29 means for withdrawing the

weft yarn

4,4 from a pair of bobbins 31, 31 mounted to the side of the loom. The yarns are simultaneously measured and fed to the nozzle assembly.

To illustrate the principle by which the

yarns

4,4 are measured and fed to the nozzle assembly reference is made to FIG. 2. The

yarns

4,4 pass from their respective bobbins 31,31 through a

brake

32,32 such as the conventional disk brake, through a comb guide 33, to which the yarns pass disposed at relatively different levels between a pair of

feed rollers

34 and 35 to the

nozzle cones

2,2. The feed roller 34 is fixed to a shaft, journalled in a stationary bearing and continuously rotated in the direction shown by the arrow. The second feed roller 35 is freely journalled at the end of a bell crank 36, opposite to the roller 34. A solenoid device 37 is located adjacent the free end of the bell crank 36 and is selectively activated by impression of an electric current (from a source not shown). The core 37 is hooked into engagement with the upper free end of the bell crank 36. A compression spring 38 is fixed between the lower arm of the bell crank 36 and the frame of the loom to maintain the roller 35 normally out of contact with the roller 34.

At the instant suitable for the insertion of the

weft yarn

4, 4 into the two opposed sheds (i.e., when weft feeding is desired) the solenoid 37 is energized to extend the core 37 upward in the direction of the nozzle, as seen in FIG. 2 to thereby pivot the bell crank 36 and bring the two

rollers

34 and 35 into engagement. The rollers draw the

yarns

4,4 from the bobbins 31, 31. At the instant feeding of weft is to cease the solenoid 37 is deenergized and the spring 38 pulls the rollers out of engagement. The action of the

brakes

32,32 limits the amount of weft which can be drawn through the

cones

2,2 by the force of the air jet blown through the nozzles. By selectively choosing and adjusting the strength of the blowing air, the time of roller contact, the degree of brake power, the length of the wefts thrown into the opposed sheds can be adjusted.

For a more accurate and precise weft feeding device, reference is made to the embodiment shown in FIG. 1. Similarly as in the first case the

weft yarn

4, 4 is withdrawn from the bobbins 31, 31 into the housing space 29. However, to the side of the loom is mounted a rotating cam 39, and a linearly reciprocating rack which engages the gear wheel fixed to a winch drum 41. The rack 40 is provided at one end with a cam follower and is mounted for reciprocal movement but resiliently loaded to maintain engagement with the cam 39. In this manner rotation of cam 39 will reciprocate the rack 40 and oscillate the drum 41, as shown by the double arrows.

A cable 42 is wound about the drum 41 and has one end stretched to extend along the housing 29 in a direction tangential to the drum 41 and is provided at its end with a light weight ball preferably made of plastic such as a table tennis ball. The ball 43 is located in an elongated tube 44 connected at its opposite end to a source of suction. By sucking through the tube 44 on the ball 43 the cable 42 is pulled taut. By varying the degree of suction on the ball 43 degree of tension on the cable 42 can be varied.

The yieldably resilient mechanism created by the

ball

43 and 44 is highly accurate and precise. It will how ever be appreciated that other means such as a compression spring may also be used at the end of the cable.

Secured to the cable 42 are a pair of eyelets or pully member 45, 45 therethrough which the

weft threads

4,4 are passed. The pullies 45, 45 may be adjustably relative to each other so as to be fixed at different distances from the drum 41 or ball 43. Located between the bobbins 31, 31 and the pully 45, 45 are a pair of

disc brakes

46,46. The

brakes

46, 46 are preferably jointly controlled by a solenoid device 46 a, to exert a selective braking action or drag on the

yarns

4,4. A common coil and core is provided for the solenoid 46 to insure joint operation of brakes. Other automatic or electromechanical braking means may be used. Located between the pullies 45, 45 and the nozzle assembly is a pair of separating roller capstans or guides 47 and 47 adapted to be vertically adjustable. In this manner the

yarns

4,4 are removed from their respective bobbins, pass through the

brakes

46, 46, the pullies 45, 45 and thence over the

capstans

47, 47 into the

cones

2,2 of the nozzle assembly. The

electromechanical brakes

46, 46 are adapted to normally exert a drag on the

yarns

4, 4 so that between the brakes and the

orifices

3,3 of the nozzle assembly the yarns are held under continuous tension. The brakes are released whenever the yarns are to be unwound from their respective bobbins.

Normally, the guide 47 is arranged below that of the guide 47, conforming to the comb 3, since in order to prevent the weft threads 4, 4' from entanglement in their path between the guides 47, 47' and the reversibly rotatable nozzles 1, it is necessary to maintain a certain sense in the relative movements of the nozzles 1. This is based on the fact that the entry point 71 of the nozzles 1 for the weft thread 4 fed from the lower guide 47, passes in the course of rotation of the nozzles 1 under the other weft thread 4' which is fed to its entry point 71' of the nozzles 1 from the upper guide 47', so that during the rotation of the nozzles l the two

weft threads

4, 4 are being kept vertically apart and do not entangle. The subsequent reverse rotation of the nozzles 1 through 180 into their initial position brings also the two weft threads 4, 4' into their initial positions.

It will be appreciated the the apparatus as shown is provided with suitable operating devices such as motors, connecting levers, control means switches, relays etc. to obtain selective sequential and cooperative operation. The mechanism required is conventional and accordingly has been omitted from the drawing for the sake of more clearly depicting the present invention.

The operation of this latter embodiment will be clearly seen by following FIG. 1. Starting from the assumption that when the last weft course has been laid in or when the weaving process is instituted the pullies 45, 45 are caused to be pulled by suction on ball 43 to the extreme left position and as close to the comb guide 33 as desired. It is thus the first step to provide a predetermined measured length of weft yarn. This is accomplished by releasing the

brakes

46, 46 and by causing the winding drum 4] under action of the cam 39 and rack 41 to pull the pullies 45, 45 to the right. Because the yarn ends are held in

cones

2,2 by action of the air blowing therein, the movement of the pullies 45, 45 causes withdrawal of

thread

4,4 from their respective bobbins into the housing 29 in the form of a loop of hairpin shape as seen. The length of the yarn may also be controlled by the initial position of the ball 43 in the tube 44. When the desired length of yarn is thus obtained, the

brakes

46, 46 may be activated, and the winding drum stopped. The yarns will thus be held under tension between the

brakes

46, 46 and the

cones

2,2 of the nozzle assembly, while the same yarns are loosely held between the bobbins 31 and 31 and the same brake means. The forces on the yarn is created by the tensioning devices formed by the drum mechanism 41 acting on cable 42, on the one hand, and the ball 43 on the other hand. Variation of either device will selectively change the tension.

The measured yarns are laid into the shed, at instant when the

reeds

24, 24 are in their most rearward, or non-beat position, and the shed formed in the warp yarns 27 is open, as seen in FIG. 3 for reception of the weft. At this instant a burst of high pressure air is delivered to the nozzle 1 and the pullies 45, 45 are released (by reversal of rack 40) to move: backward under the effect of suction on the ball 43. The

brakes

46, 46 are held in full brake position so that the force of air impulse pulls the yarns and deposits them between the warp threads 27 of the respective sheds.

It is obvious that in this manner of feeding the

yarns

4, 4 are not only premeasured to accurate and precise lengths but the speed of their delivery and feed is carefully controlled. This is of particular importance in order to control and vary the velocity of the insertion of the

yarns

4,4 into the respective sheds. It is possible by the use of this control means to avoid the formation of undesired loops or loop ends along the selvedges of the

fabric

25, 25. This is accomplished by providing each yarn with virtually independent measuring and feed means.

The

weft yarn

4,4 is normally surrounded by a volume of blowing air through the funnel cap 12, 12. When the shed is opened by the retraction of the reeds 24,24 a blast or jet of air under high pressure is impressed through the nozzle assembly and the weft length is inserted between the warp 27. After such insertion the yarns are beaten up by movement of the reeds to the completed end 48 of the

fabric

25, 25. As soon as the weft is beaten up, and laid into proper position the tread end is cut leaving it suspended in the

cone

2,2. Conventional cutting devices or thread burning devices 49, 49' comprising a holder and a resistance wire 50 and 50' connected by conductors 51 to a source 52 of electric current, are located between the orifices 3, 3' and the febric end 448. On each beat-up of the reed 24 the wires 40 and 51 burn off the weft threads 4, 4'. At this moment it is possible and may be desirable when employing different wefts to reverse the nozzle assembly 180, as explained earlier, so that the

yarns

4,4 are interchanged into the respectively opposed

fabrics

25 or 25.

While the

yarns

4,4 may cross over the opening of the nozzle assembly during reversal, the provision of separating capstans, adjustable to different heights, prevent any entanglement. The cycle of operation has thus returned to its initial phase and can begin over again.

The present apparatus has a number of advantages not found in the prior art looms. While conventional devices have been designed to insert weft under fluid pressure on looms up to to cms the weft insertion device of the present invention can be used on looms having width in excess of 3 meters which may then approach the size of contemporary gripper looms. A further advantage is obtained by the present device with regard to the efficiency of its operation. The present device can work on these wide looms at the same speed (400-500 weft insertions per minute) at which contemporary narrow jet looms operate.

A great advantage is obtained from the versatility of the present weaving loom and the possibility of turning the weft insertion device at the end of each weft laying in. Thus such fabrics may be easily formed. Because the turning of the nozzle assembly can be selectively accomplished predetermined weft patterns of perhaps multiple (e.g. 10 or 12) weft insertions of particular thread may be accomplished. It is not necessary to turn the assembly after each weft lay in. Two color goods may also be easily formed since the present device eliminates the need of handling waiting weft bobbins and gripper means by the simple expedient of reversing the nozzle assembly.

The present device also permits the formation of fabrics of unequal width. By repositioning the arm 7 along the breast beam 8 as previously explained and by adjustably varying the relative distances between the pullies 45 and 45 for example weft yarns of different length can be obtained.

It will thus be seen that the objects and advantages stated earlier have all been fulfilled. Other advantages will be clear as well. For example, in addition to being able to weave mixed wefts two or more fabrics with both different wefts and warps can be made. This is a substantial increase in versatility over the prior art. The present device provides a more uniform weave eliminating streaking and unevenness common in conventionaly formed fabrics such as silk and cottons. Weft threads of particular property can be readily chosen and used. Thus yarns, such as polyesters or polyamides may be mixed with natural yarns in any desired pattern.

It will be obvious that various modifications, changes, and equivilant mechanisms can be made to the specific devices shown and described. Because of this the present description is intended to be illustrative only of the present invention and should not be taken as limiting in any manner of its scope.

What is claimed:

1. A shuttleless loom comprising at least one warp shed forming system and a hollow breast beam extending along the length of said loom, pneumatic means for delivering yarn for the weft thereof, a supply of yarn, and means for measuring and feeding a determined length of yarn to said pneumatic means, said means for measuring said length of yarn being located in said beam, and comprising means for selectively pulling a length of yarn into said beam and brake means for holding said yarn from being pulled during feeding of said length to said pneumatic means.

2. The loom according to claim 1 wherein said loom includes a pair of opposed sheds and said pneumatic delivery means includes means for respectively delivering a pair of independent yarns to said sheds, and said means for measuring and feeding said yarn includes means for pulling and braking said independent yarns in selective sequence.

3. The loom according to claim 2 wherein said pneumatic means is rotatable to deliver yarn to each shed selectively and said measuring and feeding means includes means for maintaining said yarns separately dur ing said rotation.

4. In a shuttleless loom having pneumatic means for delivering at least one yarn from a source of supply to the warp system of a fabric shed, apparatus for measuring and determining the length of the yarns fed to said delivery means, comprising selectively operable means interposed between said supply and said pneumatic means, for withdrawing said yarn from said supply, said withdrawing means comprising a pulley mounted between opposed tensioning devices, and includes means for causing said tension devices to exert selectively operating forces on said pulley means to withdraw the yarn from the supply, selectively operable brake means located between said supply and said withdrawing means, and control means for sequentially operating said brake and withdrawing means for predetermined periods to obtain a determined length of yarn.

5. The apparatus according to claim 4 wherein said pulley is interposed between the ends of a cable, one end of said cable being wound about a rotatable winch, the other end of said cable being secured to yieldably resilient compression means, and includes means for selectively oscillating said winch to cause said pulley to withdraw said yarn in cyclical operation.

6. The apparatus according to claim 5 wherein said means for oscillating said winch comprises a circular gear connected to said winch, a rack engaging said gear, said rack having a cam follower at one end and a cam engaging said cam follower to cause said rack to reciprocate in a predetermined manner to cause said winch to rotate in periodic reversing directions.

'7. The apparatus according to claim 5 wherein said yieldably resilient means comprises an elongated tube, a source of vacuum applying a suction to said tube, and wherein said cable is provided with a ball adapted to be inserted within said tube and subject to said suction force.

8. The apparatus according to claim 4 wherein a pair of yarns are measured and two pulleys'are provided, said pulleys being arranged in tandem on said cable, and includes means for adjusting the distance between said pulleys.

Claims

3. The loom according to claim 2 wherein said pneumatic means is rotatable to deliver yarn to each shed selectively and said measuring and feeding means includes means for maintaining said yarns separately during said rotation.

7. The apparatus according to claim 5 wherein said yieldably resilient means comprises an elongated tube, a source of vacuum applying a suction to said tube, and wherein said cable is provided with a ball adapted to be inserted within said tube and subject to said suction force.

8. The apparatus according to claim 4 wherein a pair of yarns are measured and two pulleys are provided, said pulleys being arranged in tandem on said cable, and includes means for adjusting the distance between said pulleys.