US2335483A - Uniform shuttle tension - Google Patents

Description

' Nov. 30, 1943. R. E. CHARD 2,335,483

UNIFORM SHUTTLE TENSION Filed Sept. '7, i942 INVENTOR. E/cHA/ea E CHAED.

BY Q gi ATTo ENE Y.

Patented Nov. 30, 1943 UNIFORM SHUTTLE TENSION Richard E. Chard, Milford, Mass, assignor to Draper Corporation, Hopedale, Mass, a corporation of Maine Application September 7, 1942 Serial No. 457,570

'12 Claims.

. This invention relates to threading blocks for loom shuttles, and more particularly to a means for automatically controlling the tension on the the filling thread issuing from the shuttle.

In a fly shuttle loom where the filling is withdrawn from a carrier secured in the shuttle, one of the problems encountered in producing a uniform weave in the cloth is that of keeping the filling thread under an unvarying tension during the whole weaving operation.

It is common practice in the art to provide, in a threading block, a tension pad which resiliently will engage the running filling thread and create a frictional resistance on it to produce tension therein. In such prior devices, however, the pad was made to engage the filling thread constantly with a predetermined pressure, and no means were provided automatically to change the amount of the friction created by the pad to compensate for changes in the tension of the filling thread resulting from other forces imposed thereon.

It is an object of my invention to provide for a shuttle a threading block having a means therein frictionally to engage a filling thread in a manner to produce tension in it as it is being withdrawn from the side delivery eye, and to provide another means separate from but cooperating with the friction means and actuated by contact with the filling thread at a point spaced apart from the friction means to govern the operation of the latter means so that the tension producing effect of it will be regulated in accordance with the requirements arising from the working conditions of the filling.

It is another object of my invention to provide a threading block having a tension pad resiliently pressing upon the filling thread, a means separate from but cooperating with the tension pad, and actuated by the tension in the filling thread to control the action of the tension pad in a manner to cause the pressure thereof to be varied in accordance with changes in tension in the filling thread to compensate for variations in the tension arising from other sources and thereby keep the resultant tension in the filling thread substantially uniform.

It is a further object of my invention to provide a threading block, of the type described above, in which the tension pad will operate as a thread trap under the influence of the controlling de vice.

These and other objects may be attained by the construction which I have shown as an exemplary modification of my invention in the accompanying drawing, although it will be understood that I do not wish to be limited to the specific details of the form of my invention, illus-.- trated therein.

In the drawing:

Fig. 1 represents a partial plan view of a shut-, tie with a filling carrier therein, and shows the disposition in the shuttle of a threading blockembodying my invention;

Fig. 2 represents an elevational view of a section of the threading block, taken approximately on the line 2-2 of Fig. 1; v

Fig. 3 represents an elevational view ofv an end of the threading block, looking toward the filling carrier, and shows the position assumed by a fill-, ing thread in it when not under tension;

Fig. 4 represents a sectional plan view of the threading block taken approximately on the line- 4-4 of Fig. 6, and shows the position assumed Fig. 5 represents the same sectional plan view 7 of the threading block as shown in Fig. 4, and shows the position assumed by the parts when the filling thread is under comparatively high tension;

Fig. 6 represents an elevational view of anend of the threading block looking away from the filling carrier and toward the point of the shuttle; Fig. 7 represents a sectional view in elevation of the threading block, taken on the line 1--1 of ig. 1; I Fig. 8 represents a plan view of the bottom sur-' faces of the threading block.

Referring to the drawing, the shuttle [has a filling carrier 2 attached within it, from which the filling F is unwound and led through the threading block 3 which directs it to the side delivery eye 4 from whence it is continuously drawn to be woven into a fabric. This arrangementis well known in the art and therefore an-extended: description of it is not thought to be necessary: here.

The threading block may be made ofmetal, or other suitable material, and is constructed so; that it may be inserted in a recess in the body. of the shuttle and secured therein in a; manner; well known in the art.

Within the threading block is formed a longito, and is in communication with, the top' surface 8 of the threading block. The threading block is placed in the shuttle so that the longitudinal passage is in alignment with the filling carrier, and the top surface is so shaped that a thread drawn from the filling carrier and along the top surface will be led down into the thread passage.

A projection 9 is formed on the threading block, extending downwardly from the top thereof, and is placed outwardly of the end of the thread passage in a position to engage a filling thread running through the passage and lead it transversely of the shuttle into the space Ill and out of the side delivery eye 4. A post ll may be placed on the threading block adjacent the side delivery eye to form a bearing surface for the running filling thread.

During normal operation the filling thread will contact surfaces of the threading block and thereby encounter frictional resistance to its travel. The drag produced will result in the thread being drawn from the side delivery eye under tension.

A certain amount of tension in the filling thread is essential if it is to be laid properly in the shed. However, with some types of filling thread and under some operating conditions the tension produced by such means has not been found adequate. In such cases in order to assure that the filling thread will operate under proper tension, it has been proposed to place a device in the threading block to engage the filling thread and increase the tension thereon. Such a device may have various forms, one of which is shown in the drawing.

As illustrated, the friction device may coinprise an element l2, known as a tension pad, positioned to engage the filling thread in its travel through the threading block, and, under the influence of a spring l3, force it into more intimatecontact with a surface of the thread passage, thereby increasing the friction on it.

In the device illustrated, the tension pad has an inverted L shaped formation, one end portion M of which is loosely inserted into an opening l5'formed in the wall of the threading block. The other end portion of the tension pad has an opening l6 formed in it, and through this opening is placed a pin I1, the ends of which are secured in the body of the block. In this manner, the tension pad is constrained from moving out of its set position longitudinally of the threading block, but is free to move laterally of the thread passage.

'An opening I8 is placed in the wall 8 in approximate alignment with the center point of the tension pad, and is screw threaded to receive a set screw 19. The spring 13 is inserted through the opening it into engagement with the back of the tension pad [2, and the set screw'lB is threaded into the opening to abut the spring and cause it to press the tension pad against the wall I of the thread passage.

The top portion of the tension pad is rounded, as at 20 to form an entry for the thread as it is being led into the thread passage 5.

It will be seen from this construction that as the filling thread enters the thread passage from the top of the threading block, it will assume' a position between the tension pad and the side wall 7 of the thread passage, and during subsequent operations the tension pad will afiect the amount of friction imposed on the thread.

".In'suc'h a device the pressure of the tension pad on the thread can be regulated by removing the shuttle from the loom andmanipulating the set screw l9. However, the adjustment cannot be made while the shuttle is in operation. The tension pad, therefore, will generate a fixed amount of tension in the filling thread at its point of pressure application regardless of the amount of tension occurring therein due to the conditions under which the filling thread is operating at the time.

It is well known that the tension in the filling thread varies considerably over a wide range during normal loo-1n operations, and my invention contemplates the use of a means to regulate the tension resulting from the friction devices that it will be effective only to the amount needed at a particular instant.

It might be well to note some of the circumstances affecting the tension in the filling thread during the Weaving operation,

It is usual practice detachably to secure the filling carrier within a recess in the shuttle body and to dispose it longitudinally of the shuttle so that the tip of the carrier is adjacent the threading block and the base is grasped by a holding means.

As the filling is unwound from the carrier, that part of it adjacent the tip is withdrawn first, and subsequently other portions farther from the tip, so that the filling is unwound from the carrier progressively from the tip to the base portions thereof.

By this construction, as the filling is withdrawn from the carrier it is unwound circumferentially around it and passes along the body of the carrier in a longitudinal direction until it is released at the free tip portion, from whence it runs through the threading block.

The filling thus comes in contact with increasingly greater lengths of the exposed portion of he body of the filling carrier, and the frictional resistance on the filling thread due to this contact continuously increases. As a result the'tension of the filling being woven into the cloth is constantly changing. Because of this, imperfect cloth is sometimes produced. I

Another factor afiecting the tension of the filling thread occurs when the shuttle is checked at the end of its travel through the shed. On coming into the shuttle box the shuttle is checked very'abruptly, and the inertia of the filling thread tends to cause an excessive amount of filling to be unwound after the shuttle is stopped. Unless means are provided to prevent it, the filling thread will continue to be drawn through the threading block to relieve any tension on the thread, and the filling will be in a slack condition when it is beaten into the fell, resulting in imperfect cloth.

If a tension pad is placed in the thread passage, as shown in the drawing, it will impose sufiicient resistance on the filling to cause it to remain under tension after the shuttle is checked, even though an over supply of filling has been unwound from the filling carrier during the checking operation.

in the carrier receiving recess of the shuttle from whence it will be drawn on subsequent loom operation.

In order to control the amount of friction placed on the filling thread to compensate for changes in tension arising therein, I have provided a means which will be actuated by the tension in the filling to affect the pressure produced by the tension pad.

This means may comprise a lever member 2| The action of the tension pad will cause the excess filling to be retained I placed in a channel 22 formed in the bottom surface of the threading block, and extending longitudinally thereof in a plane parallel to the central plane of the thread passage 5. The lever member is loosely secured in the channel so that it may have a rotary motion therein.

The end of the lever nearest the tension padv is bent upwardly in a hook-like formation which is made to embrace loosely the pin I! to which the tension pad is affixed. This hook-like end bears against the tension pad on the same side as that contacting the wall 1 of the thread passage. A recess 24 is formed in the body of the threading block to permit the end 23 of the lever to be inserted in this position.

Th other end of the member 2| is bent upwardly at an angle which will cause it to extend transversely of the end of the thread passage 5, as at 25, and is further bent as at to place the terminus 21 of the lever member in a cavity 28 formed in the under part of the top surface 8 of the threading block. The end 2'! of the lever is thus mounted in the threading block in such a position that a thread entering the thread passage from the top surface 8 will engage the portions 26 and 25 of the lever and remain in contact with it as it is guided out of the side delivery eye.

The proportions of the lever member 2| are such that the bent portion 25 lies opposite the space ill.

The lever member is placed in a position in relation to the cavity 28, the channel 22 and the recess 26 with such clearance that it may be rotated slightly to cause the end portions 23 and 25 to move transversely of the thread passage 5.

A member 29 is aiilxed to the bottom of the threading block to retain the lever member 2| in operative position. The member 29 may be held in position by an ear 30 contacting a face of the shuttle block, as at 3!, and an upturned portion 32 contacting another face of the threading block as at 33, the dimensions of the parts being such that the resiliency of the material from which th member 29 is made will cause the parts 3!! and 32 to contact the faces of the shuttle block with sufiicient force to hold the parts together until the threading block is securely fastened in the shuttle.

The upturned portion 32 of the member 253 may be extended upwardly along the adjacent face of the threading block to a point near the top surface thereof, and it may have formed in it an opening 34 in alignment with the center of the thread passage 5. The opening 34 has at the top a narrow thread passage 35 in a position to cause a filling thread being led into the threading block to enter into it.

In this manner there is provided a thread trap which will prevent the filling thread from swirling out of th threading block as it is unwound from the filling carrier.

A notch 36 placed in the end of the thread passage wall 7 adjacent the tension pad forms a means whch enables uneven portions, such as knots, in the filling thread to enter between the tension pad and the side wall of the thread passage without catching on the parts and causing the thread to break. The notch also aids the filling thread to maintain a central running position.

Under working conditions, a filling thread will pass from the filling carrier, through the opening 34, between the tension pad I? and the wall 1, along the thread passage 5, around the portion 25 of the lever member 2|, through the sion.

space H] and thence through the side delivery eye of the shuttle.

When there is no tension in the filling thread, the tension pad will exert its full spring pressure thereon as shown in Fig. 3. However, as the tension in the thread increases, the thread will act on the end portion 25 of the lever member 2| to rotate it in the direction of the side delivery eye. This will cause the end portion 23 of the lever member 2| to be rotated in the same direction.

Since the end portion 23 bears against the tension pad, and since it is restrained by the channel 22 from moving transversely of the thread passage, the result of the rotation will be to cause the bottom of the tension pad to be forced away from the wall 1, and thereby exert less pressure on the filling thread. When the bottom of the pad is moved in this direction, th spring l3 will act as a fulcrum about which the pad will pivot to cause the top portion thereof to remain in contact with the wall 1. Therefore, although the pad is forced entirely out of contact with the filling thread, the position of the pad will cause the thread to remain in the space between the pad and the wall of the thread passage.

When the pressure exerted by the tension pad is reduced, the tension in the filling thread will be decreased. The force on the lever member 2| will be diminished until it will not be sufficient to cause further rotation of the parts, and they will reach a state of equilibrium in which the filling thread is being withdrawn at the proper ten- If the tension of the filling thread becomes excessive, the part 25 of the lever member 2| will be rotated an amount suiiicient to cause the ten sion pad to be displaced far enough from the wall I so it will no longer contact the filling thread, and hence will be entirely ineffective to create additional tension. This condition is shown in Fig. 5.

It will be seen, therefore, that the pressure of the tension pad is automatically controlled to compensate for tension arising in the filling thread from other sources. The control is positive and instantaneous.

When the tension on the filling thread is sud-- denly relaxed, the lever member 25 will be no longer effective to control the action of the tension pad and the full pressure thereof will be exerted on the thread. This condition occurs when the shuttle is checked in the shuttle box. Therefore, at this time, the full pressure of the tension pad is made available to hold the filling thread at the proper tension while it is being beaten into the fell.

Having thus described a preferred embodiment of my invention, I claim:

1. In a shuttle for an automatic filling replenishing loom, a threading block having a thread passage therein, a friction means in said threading block and positioned frictionally to engage a filling thread passing through said block, and

a second means separate from but cooperating with said friction means and constructed and arranged to be actuated by said filling thread to cause said friction means to be effective to vary the friction on said filling thread in inverse relationship to the tension in said thread.

2. In a shuttle for an automatic filling replenishing loom, a threading block having a longitudinal thread passage therein, a tension pad placed in said thread passage and positioned to press a filling thread between said tension pad and a wall of said passage, and means separate frombut cooperating with said tension pad and actuated by said filling thread to cause .the pres sure of said tension pad on said filling thread to be effective in inverse relationship to the tension therein.

3. In a shuttle for an automatic filling replenishing loom, a threading block having a longitudinal thread passage therein, a tension pad placed in said thread passage and positioned to press a filling thread between said tension pad and a wall of said passage, and means separate from but cooperating with said tension pad and actuated by said filling thread to cause the pressure of said tension pad on said thread to decrease as the tension therein increases.

4. In a threading block for a loom shuttle, a longitudinal thread passage, a spring pressed tension pad placed in said passage and positioned to press a'filling thread between said tension pad and a wall of said passage, and means in said threading block separate from said. tension pad but in engagement therewith and with the filling thread, and cooperating with said filling thread and said tension pad to cause the pressure of said tension pad to be effective in inverse relationship to the tension in said filling thread.

5. In a threading block for a loom shuttle, a thread passage, a friction means positioned in said passage to. engage a filling thread, and means in said threading block separate from said friction means and cooperating with said friction means and said filling thread to cause said friction means to be effective to create friction on said filling thread in inverse relationship to the tension therein.

6. In a threading block for a loom shuttle, a longitudinal thread passage, a spring pressed tension pad placed in said passage and positioned to press a filling thread between said tension pad and a wall of said passage, and means in said threading block separate from said tension pad but in engagement therewith and with the filling thread, and cooperating with said filling thread and said tension pad to cause said tension pad to reduce pressure on said filling thread as the tension therein increases.

7. In a threading block for a loom shuttle, a longitudinal thread passage, 2. spring pressed tension pad placed transversely of said passage and positioned to press a filling thread between said pad and a side wall of said passage, a lever member operably mounted in said threading block and having a portion positioned to engag the filling thread and another portion positioned to engage the tension pad, said lever member being mounted so that the said portions are capable of movement transversely of the thread passage, said lever member being separate from said tension pad and being constructed and arranged to be actuated by the filling thread to cause the tension pad to engage the fill ng thread with a pressure inversely proportional to the tension in said thread.

8. In a threading block for a loom shuttle, a longitudinal thread passage, a resiliently mounted tension pad positioned to move transversely of said thread passage to press a fil ing thread between said pad and a side wall of sa d passage. a lever member operably mounted in said threading block and having a portion positioned to engage the filling thread and another portion positioned to engage the tension pad, said lever memher being mounted so that the said portions are capable of movement transversely of the thread passage, said lever member being separate from said tension pad and being constructed and arranged so that it will cooperate with the filling thread and the tension pad to cause the portion of the lever member engaging the said pad to force the said pad to decrease pressure on the filling thread when the other portion of the lever member is moved transversely of the thread passage by the filling thread unde tension.

9. In a threading block for a m shuttle, a longitudinal thread passage, a tension pad resiliently mounted for movement transversely of said passage and into engagement with a side wall thereof and positioned to engage a filling thread between said pad and the said wall, and means in the threading block cooperating with the filling thread and the tension pad and constructed and arranged to be actuated by the filling thread under tension to force the bottom portion of the tension pad out of engagement with the said side wall while the top portion of said pad remains in contact therewith.

10. In a threading block for a loom shuttle, a longitudinal thread passage, a spring pressed tension pad positioned to move transversely of said passage to press a filling thread between said pad and a side wall of said passage, a lever member operably mounted in said threading block and having a portion in contact with the lower part of the tension pad and another portion positioned to engage the filling thread at a point spaced apart from said tension pad, said lever member being mounted so said portions are capable of movement transversely of the thread passage and being constructed and arranged to be actuated by the filling thread to force the lower portion of said tension pad away from said side wall against the spring pressure to cause said tension pad to relieve the pressure on the filling thread.

11. In a loom shuttle, a longitudinal recess containing a filling carrier, a threading block placed at one end of the shuttle and having a longitudinal thread passage in substantial alignment with and in communication with said recess, a friction means positioned at the end of said longitudinal thread passage adjacent said recess, said friction means comprising a spring pressed tension pad movable transversely of the thread passage and positioned resiliently to engage a filling thread between said pad and a side wall of said thread passage, a lever member placed in said threading block longitudinally of said thread passage and having one end portion thereof bent at substantially a right angl and positioned transversely of the said thread passage adjacent the end opposite to that containing the friction means and the other end portion of said lever member having a hook-like formation, said hook-like portion being positioned to lie flat against said tension pad on the thread engaging side thereof, said lever being mounted in the threading block in a manner to permit the said end portions thereof to be moved pivotally transversely of the thread passage, said lever being so constructed and arranged that the said. right angled end portion thereof will be moved pivotally transversely of the said thread passage under the action of tension in a filling thread passing through said threading block and thereby cause the said hook-like end portion to be moved pivot ally transversely of the thread passage in a manner to engage the said tension pad and cause it to move away from the filling thread engaged between the said tension pad and the said side Wall of the thread passage to thereby reduce the frictional effect of the tension pad on the filling thread.

12. In a shuttle for an automatic filling replenishing loom, said shuttle having a hollow longitudinal portion for accommodating a filling carrier, and a side delivery eye, a threading block having a longitudinal thread passage therein communicating with the top surface of said threading block, said surface being formed to guide a filling thread into said thread passage, a friction means placed at one end of said threading block in a position to engage a filling thread as it enters the said thread passage, said friction means comprising a tension pad mounted on one vertical side wall of said thread passage and spring pressed into engagement with the other vertical side Wall thereof, said tension pad being formed at the top portion thereof to provide means for a filling thread to be inserted from the top surface of said threading block to a position between the said tension pad and the said side wall engaging it, said tension pad being constructed and arranged so the top portion of said pad will contact the said side wall of the thread passage when the filling thread is in the aforesaid position to thereby form a trap for the filling thread, a lever member mounted in a channel in the bottom of the threading block and longitudinally thereof, said lever member having an upturned portion at one end engaging the bottom part of said tension pad and an upturned portion at the other end extending upwardly from the bottom of said threading block and transversely of said thread passage terminating in a recess in the under side of said top surface said last named upturned portion of the lever member being positioned to engage a filling thread led into said thread passage from said top surface of the threading block and at a point between the thread passage and the said side delivery eye of the shuttle, said lever member being mounted in the threading block in a man ner to permit said upturned end portions to be moved pivotally transversely of said thread passage, said lever member being constructed and arranged to cause the thread engaging upturned portion thereof to be moved pivotally transversely of the thread passage under the action of tension in the filling thread and to thereby cause the other upturned end portion of the lever member to contact the bottom part of the tension pad and force it against the spring pressure occurring on it to reduce the pressure imposed on the filling thread placed between the tension pad and the vertical side wall of the thread passage.

RICHARD E. CH-ARD.

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