US3131729A - Weft thread supply system for looms for weaving - Google Patents

WEFT THREAD SUPPLY SYSTEM FOR LOOMS FOR WEAVING Filed Dec. 5, 1960 5 Sheets-Sheet s 43

H

6. wm mm 2 v T May 5, 1964 H. R. LEYSINGER 3,131,729

WEFT THREAD SUPPLY SYSTEM FOR LOOMS FOR WEAVING Filed Dec. 5, 1960 5 Sheets-

Sheet

4 0 00 /0 0 0 0 0 0 0 000000 B I w n 0 0 0 0 0 0 fl.

With the system according to the invention the balloon formed by the thread which is unwound from the accumulating device can be maintained due to the continuous rotation of the accumulating device so that the balloon does not collapse between two shuttle picks as is the case with he balloon formed by the threads unwinding from the Storage spools of conventional looms, and twisting and i 'nation of loops are avoided. Twists and loops which quently occur between two picks in the threads pulled United States Patent The

elements

30, 34, 38 and 20 3,131,729 Patented May 5, 1964 from the storage spools of conventional looms are straightened out by the shuttles after they are picked into the shed whereby the thread tension, particularly of heavy yarns, is increased and the speed of the shuttles is reduced unless the thread breaks, as it happens once in a while. In conventional looms the twists are not always straightened out and move into the shed which is also not desired.

Referring more particularly to FIG.Ll of the drawing,

numeral

5 designates a shaft which is fixed to a part of the frame of a loom for weaving of the gripper shuttle type, not shown, and having astoragespool for a weft thread which spool is placed outside of the shed. Bearing bushings 30 and 34 are supported on theshaft S'by means of

rollers

31 and 32. The bushing 34 supports a

sleeve

38 which, together with the bushing.30, supports an

element

6 forming the star of a swiftlike device. The

sleeve

38 has an annularoutside shoulder and the element 6has an annular inside shoulder between which shoulders a

coil spring

20, which is coaxial of the

shaft

5, ispIaced. rotate together with the

element

6, the. latter being axially movable on the

sleeve

38. The

spring

20 tends to move the

element

6 together with the bushing 30 to the left until a conical end surface 21 of the

element

6 which end surface is coaxial of the shaft abuts against a corresponding

conical surface

28 of a

member

9 which is fixed to the

shaft

5 and which forms the worm wheel of a worm gear whose purpose will be described later. An

axial bearing

33, arranged between the bushing 34 and an

annular member

35 which is fast on the

stationary shaft

5, and a collar on the bushing 34 prevent axial displacement to the right of the bushing 34 and of the

sleeve

38 under the influence of the

spring

20.

One end of the

element

6 is provided with an

annular protuberance

49 which supports, for example, four

rollers

2 individually provided with worm wheels which engage the

worm

9. An

annular protuberance

50 at the opposite end of the

element

6 rotatably supports an equal number of

rollers

3. The

rollers

2 and 3 are arranged in pairs, each pair being placed in a radial plane including the longitudinal axis of the

shaft

5. An

endless belt

1 extends around each pair of

rollers

2, 3, the belt being made of a material having a rough surface, for example leather, rubber, or a synthetic material.

The

element

6 is provided with a

pulley

7 driven by a

belt

8 which is preferably driven by a separate electric motor or by the drive of the weaving machine through an infinitely variable transmission. Upon rotation of the

element

6 around the

shaft

5 the

belts

1 move in the directions of the

arrows

4, i.e. the outer runs of the belts move from left to right, as seen in FIG. 1. A

weft thread

23 pulled from a weft thread storage spool, not shown, runs through a thread brake 13 and a

guide eye

12 tangentially on the swift and is wound thereonto for producing a

single layer

22 comprising, for example, between 40 and 50 windings. The

thread

23 unwinding from the swift forms a

balloon

41 which rotates around the axis of the

shaft

5, the

thread

23 subsequently passing through an

eye

43 mounted in a

shield

42. After passage through the

eye

43 the weft thread travels through a thread tensioner, and therefrom to a device for presenting the weft thread to a shuttle. These elements do not form part of the present invention and are not illustrated. A

disc

44 is mounted to the right end of the

shaft

5 and has a rim which is bent over the

rollers

3 for preventing entanglement of the

thread

23 with the swift mechanism, should the

balloon

41 collapse.

Levers

15 are pivoted by

pins

16 to the

annular protuberance

50 at the right side of

element

6 to swing in radial planes including the longitudinal axis of the

shaft

5. Each

lever

15 has an arm portion which is substantially parallel to the

shaft

5 and has a U-shaped cross sectional configuration and forms a

channel

45 for receiving the outer run of a

belt

1. The lateral portions of the aforedescribed arm portion are provided with

guide surfaces

46 which are so placed that undesired surplus windings of the

layer

22 of

weft thread

23 wound on the swift run onto the guide surfaces. Each

lever

15 is provided with a

nose

17 extending into a

cavity

37 of the

sleeve

38.

The rotational speed of the swift is so adjusted that the amount of

weft thread

23 running onto the swift per time unit corresponds to the amount of weft thread unwound from the swift and passing through the

eye

43 so that the axial extension of the

thread layer

22 remains constant. The

levers

15 are pressed outward by centrifugal force against the outer runs of the

belts

1. If, for any reason, less thread is pulled through the

eye

43 from the swift than is supplied through the

eye

12 to the swift, the axial extension of the

layer

22 of thread windings in FIG. 1 increases towards the right and surplus windings are pushed onto the guide surfaces 46 of the

levers

15, whereby the levers are rocked in counterclockwise direction. This causes movement of the

element

6 together with the

pin

16 to the left until the

surfaces

21 and 28 are in engagement and the rotation of the swift is braked,

causing slippage of the

belt

8 on the

pulley

7. The speed of rotation of the swift is reduced and less windings of weft thread are wound on the swift so that the surplus windings riding up on the

surfaces

46 gradually disappear and the

levers

15 move in clockwise direction until they are once more in the position shown in FIG. 1. The brake surface 21 is now disengaged from the

surface

28 and there is no slippage between the

belt

8 and the

pulley

7 so that the swift can rotate at its previous speed.

The arrangement shown in FIGS. 1 to 3 does not include means for increasing the speed of the swift when more weft thread is pulled through the

eye

43 than is supplied through the

eye

12 and the normal speed of the swift must be somewhat greater than is required for continuously delivering an average length of weft thread per time unit. Braking of the swift by the aforedescribed mechanism causes reduction of the speed of the swift to the speed needed for delivering the normally required amount of thread.

FIG. 4 shows only the more important parts of a modified swift and also a weft

thread storage spool

14, unwinding of weft thread from which is accompanied by formation of a

balloon

41. Equivalent parts are designated by like numerals in FIGS. 1 to 4. The

element

6, which is rotatably supported by the free end portion of the

stationary shaft

5, is provided with an

annular rim

25 which rotates with the swift. The

annular rim

25 carries a

traveler

24 through which extends the

thread

23 unwinding from the swift. The centrifugal forces produced by the

balloon

41 formed by the

thread

23 and of the

traveler

24 determine the friction effect produced by the relative movement of the

rim

25 and the

traveler

24.

If no thread is pulled through the

eye

43, the

traveler

24 does not move relatively to the

rim

25 and the traveler as well as the

balloon

41 rotate at the same speed as the swift. If thread is pulled through the

eye

43, the

traveler

24 moves relatively to the

rim

25 in a direction which is opposite to the direction of rotation of the rim. If the same length of thread is pulled through the

eye

43 as is running on the swift through the

eye

12, the rotational speed of the

traveler

24 relative to the rotational speed of the

rim

25 is the same as the rotational speed of the

rim

25 relative to the

shaft

5, but in opposite direction; the traveler, therefore, stands still and the

balloon

41 disappears. If more thread is unwound from the swift than is wound thereonto, the absolute rotational speed of the

traveler

24 remains opposite, but is greater than the rotational speed of the

rim

25. The

traveler

24 assures that a

balloon

41 is maintained also when no thread is pulled through the

eye

43 so that thread is not unwound from the swift by gravity, as may be the case when working with heavy yarns.

The abscissa of the diagram shown in FIG. 5 represents time t and the ordinate represents the velocity v at which a weft thread is inserted in the shed.

Curve

26 shows the velocity of the weft thread caused by the consecutive passages of shuttles through the shed. The velocity varies between zero at the points marked A and a maximum at the points marked B. The shaded area C corresponds to the length of weft thread inserted in the shed of the loom per pick. The dash-

dot line

27 represents the constant speed at which weft thread supplied by the

storage spool

14 in FIG. 4 is wound onto the swift. The

straight line

27 is at least so high above the abscissa that the area of the shaded rectangle D is equal to the area .0.

In the diagram shown in FIG. 6 the abscissa represents time t and the ordinates represent the absolute rotational speed n of the traveler24 and of the

balloon

41. At the points marked F no thread is pulled from the swift and the negative rotational speed n and the direction of movement of the

traveler

24 and of the

balloon

41 are the same as the rotational speed of the swift. No thread is pulled from the swift during the time when an idle shuttle is prepared for the subsequent pick. At the points marked E the length of weft thread unwound per time '5 unit from the swift is equal to the length of weft thread wound onto the swift and the absolute speed n of the traveler is zero; the

traveler

24 stands still and the

balloon

41 disappears. At the points marked G the rotational speed is the same as at the points marked F, but the direction of rotation is opposite. In other words, the rotational speeds of the

traveler

24 and of the

balloon

41 are equal to the difference between the maximal unwinding speed and the constant winding speed divided by the circumference of the

rim

25. The direction of rotation of the

balloon

41 is opposite to the direction of rotation of the swift. The rotational speed of the balloon at the points G is never greater than the difference between the maximal unwinding and the constant winding speed divided by the circumference of the

rim

25. In conventional looms for weaving where there is no intermediate accumulating swift, the maximal rotational speed of the balloon formed at the thread storage spool is equal to the maximal speed at which the weft thread is inserted into the shed divided by the circumference of the storage spool at the respective moment. Due to the very great maximal weft insertion velocity the maximal rotational speed of the balloon in conventional arrangements is very great, causing great stress, particularly when the diameter of the storage spool becomes small as is the case when the thread on the storage spool becomes exhausted.

The embodiments of the invention shown in FIGS. 1 to 4 show a weft thread accumulating swift whereby the Weft thread is wound on the outside runs of the

belts

1. FIG. 7 illustrates a device where the weft thread is wound on the inside runs of the belts. The device shown in FIG. 7 comprises a tubular member or hollow shaft 63 mounted on a

portion

61 of the loom and held fast thereon by a

screw connection

62. A hollow cylindrical part of an element 6' is rotatably supported by the member 63 by means of two

ball bearings

64 and 65. Belt drives corresponding to the belt drives 1, 2, 3, of the device shown in FIG. 1 are rotated about the longitudinal axis of the member 63 in the same Way as the beltdrives are rotated in the embodiment shown in FIG. 1. The device shown in FIG. 7 may be used in vertical or horizontal position. The

Worm Wheels

10 are driven by a

worm

9 formed on the member 63.

Rollers

66 and 67 forming a nip are rotatably mounted in an aperture in the member 63 and are placed in a radial plane including the rotation axis of the swift formed by the

element

6 and the

belts

1. The roller 66 is driven by

bevel gears

68, 69, the latter being mounted on a shaft 71 to which a

gear

72 is rigidly connected. The teeth of the

gear

72 engage

internal teeth

73 provided on the cylindrical portion of the element 6'. Weft thread is supplied through the interior of the mem ber 63 and seized in the nip formed by the

rollers

66 and 67. The

gears

73, 72 and 69, 68 are so dimensioned that the circumferential speed of the

rollers

66 and 67 substantially equals the circumferential speed of the inside of the inner runs of the

belts

1.

The

weft thread

23 coming from the storage spool, not shown, is applied by the

rollers

66, 67 to the inside of the inner runs of the

belts

1 and held thereon by centrifugal force so that a

layer

22 of windings is formed. The

thread

23 unwound from the

layer

22 is removed through the hollow 74 of the element 6' and conducted to the shuttles.

The aforedescribed swi'fitlike devices may include, for example, four belt drives or six belt drives, or only two belt drives. Instead of narrow belts, ribbons may be used made of elastic material and having a width corresponding to a considerable portion of the circumference of the layer of windings to be produced by the swift. In this case, rather long, barrel-shaped rollers may be used instead of the rollers shown in FIGS 1 to 3. An essential feature of the device according to the invention is that the

layer

22 is moved in axial direction of the swift.

Instead of the illustrated and described means for automatically regulating the speed of the swift, other con- 6 ventional devices may be employed, for example, an optical regulating device. In this case an undue increase of the axial extension of the

layer

22 may cause interruptionof a light beam and a lightsensitive device may be employed for reducing the rotational speed of or for temporarily stopping the swift. The light beam is not interrupted when the rotational speed is normal. A second light beam may be provided which is interrupted when the

layer

22 has the desired axial extension and is not interrupted when the length of the

thread layer

22 is less than a predetermined The uninte-r rupted second light beam meets a light-sensitive control device which causes speeding up of the swift until sufficient thread is wound onto the swift to produce the desired length of the

layer

22.

3. In a weaving machine according to

claim

2 and wherein the outer runs of said belts form said thread carrier means, said sensing means including a lever pivotally connected to said support means for swinging in a radial plane including the rotation axis of said support means, said lever having an arm having a portion adjacent to the outer run of one of said belts, said arm having a surface portion inclined with respect to the rotation axis ofsaid'sup'port means and having an end facing the end of the layer of weft thread Wound on said carrier means, the distance of said end of said surface portion from the rotation axis of said support means being smaller than the distance of the outer surface of the run of said belt, to which said arm portion is adjacent, from the rotation axis of said support means, the distance of said surface portion from the rotation axis of said support means gradually increasing with increasing distance from the layer of weft thread wound on said carrier means, the thread wound on said carrier means running onto said surface portion upon advance of the thread layer beyond a location determined by said arm portion and pressing said arm portion toward the rotation axis of said support means and rocking said lever, said control means being responsive to the rocking of said lever.