US2224097A - Thread tensioning device - Google Patents

Description

Dec. 3, 1940. H H BURDETT 2,224,097

THREAD TENS IONING DEVICE Filed May 13, 1940 `ATTORNEY- Patented Dec. 3, 1940 UNITED STATES THREAD TENsIoN'ING DEVICE Horace H. Burdett, Milford, Mass., assignorto Draper CorporatiomHopedale, Mass., a corporation o! Maine Application May 1a, 1940, serial No. 334,804

6 Claims.

This invention pertains to automatically threading loom shuttles and has more particular reference to such shuttles having automatically threading tension devices for applying tension to the running filling thread.

Shuttles of the type mentioned are used in bobbin changing looms 'wherever the character of filling thread employed or cloth being woven is such as to require more tension on the filling lo thread than is obtainable with shuttles having simple threading blocks. Of the various types of tension devices heretofore proposed, the spring clamp type, so-called. is to be preferred froml the standpoint of simplicity and ruggedness of 5 design and also because of the more uniform tension which it provides.

However, such prior spring clamp tension devices have been unsatisfactory in that they failed to provide a suiiiciently uniform tension and sumciently fine adjustment of the tension.

.The principal object of the present invention is to provide, in an automatically threading tension device of the spring clamp type. means whereby a. more uniform tension is produced and finer adjustment of the tension is readily obtainable.

Other objects and advantages of the invention will be made manifest in the following more detailed description of the preferred embodiment of the invention and by reference to the accompanying drawing, wherein:

Fig. 1 is a plan View of the thread delivery end of the shuttle;

Fig. 2 is a. view in section as indicated by line 2-2 of Fig. 3; and

Fig. 3 is a view in cross-section taken on line 3-3 of Fis. 2.

The shuttle shown on the drawing is comprised of a shuttle body I having a cavity 2 for receiving an automatically replaceable filling carrier such as bobbin, a threading block 4, and a side delivery eye 5. The shuttle body may be provided with a thread trapping wall 6 as more fully disclosed in patent to W. I. Stimpson, No. 1,985,960,

granted Jan. 1, 1935.

' The shuttle has a longitudinally extending thread passage 1 which is in alignment with the cavity 2. The thread passage or as much thereof as is in the threading block 4 is defined by the front wall 8 and the rear wall 9 of the threading block.

A guard or horn I0 projects from the front wall 8 outwardly and rearwardly, as in the said Stimpson patent. The term "outwardly" is herein used to mean in a direction from the cavity'2, longitudinauy of the shutue toward the up, 1. e. toward the right on Figs. 1 and 2.` Other expressions denoting direction are applicable to the shuttle when the same is considered to be positloned in the loom. 5

The shuttle is provided with a tension device, which device may comprise a pair of friction members yieldingly pressed together for exerting a slip-grip upon the running filling. The tension device as shown is preferably carried by the 10 threading block at theinner end ofthe thread passage in the latter, there being a front friction member II and a rear friction member I2. The members II and I2 extend transversely of the filling thread and thread passage, preferably at 15 an angle to the perpendicular axis of the threading block 4 as best shown by Fig. 3. l

The particular friction members II and I2 shown on the drawing, may be formed from elongated bodies of fiat steel bent into the shape 20 best shown by Fig. 3. The upper end of friction member II isprovided with a horizontally extending guide lug I3 entering into a bushing I4 in a recess I5 in the threading block 4, whereby the friction member is movably guided and sup- 25 ported. The upper end of friction member i2 is provided with a horizontally extending lug IB entering into a. bushing I'l in a recess I8 in the threading block 4, whereby the friction member is movably guided and supported. The friction 30 members Il and I2 are provided adjacent their bottom ends with aligned holes I8 and 20 respectively for the reception pf supporting means. The supporting means shown may comprise an adjustable screw 2| threaded intothe rear wall 35 9 and having a pin 22 projecting from'its forward end. The pin 22 being received in an opening 23 in the front wall 8, the pin 22 passes through the holes I9 and 20 in the friction members II and I2 and supports said friction members. The in- 40 ner face 24 of the screw 2l abuts the rear friction member I2. By turning said screw the friction members II and I2 may be adjusted in 4their relation to the side walls of the thread slot.

'The friction members II and I2 may be yield- 45 ingly pressed together by suitable spring means. In the construction shown, member I2 is pressed toward member II by a spring 25 which engages between member I2 and an adjusting screw 26 threaded into the rear wall 9 of the threading 50 block. Member II is pressed toward member I2 by a spring 2l which engages between member II and an adjusting screw 28 threaded into the front wall 8 of the threading block.

An important featureof novelty of the shuttle 55 shown resides in the relative location of the spring means such as 25 and 21. .As best seen on Fig. 3 these springs are staggered in. relation to each other.

5 In the prior types of springclamp tension devices where the tension means are in horizontal axial alignment, there is a tendency for the friction members to press against the running filling thread with a varying pressure. Starting with l0 slight pressure at the entrance end the pressure increases up to the point of location of the tension means and decreases from that point downward to the bottom of the friction members. Thus the pressure exerted by the friction members is not uniform throughout their length. By

vertically spacing the tension means, a more uniform pressure is exterted by the friction members throughout their length. 'I'he inner face 24 of screw 2i acts as an abutment about which members il and l2 are moved by tension springs 25 and 21. Spring moves the members clockwise about the abutment and spring 21 moves the members counter-clockwise about the abutment (as viewed on Fig. 3). Due to the fact that 25 spring 25 is located further from the abutment 24 than is spring 21, the pressure exerted by membersl H and I2 againsteach other, and of course against the running liing thread therebetween,

will be substantially uniform throughout their lengths.

' Also by having the adjusting tension means spaced vertically a finer adjustment of the ten-v sion exerted by the friction members can be obtained. Because of their location in relation to the friction members II and I2, the front and rear tension springs exert a different pressure against the filling thread. It has been found that one turn of the back adjusting screw 26 is equal to approximately one halfturn of the front 40 adjusting screw 28. 'I'his is very important in obtaining the fine adjustments necessary -for yarns such as rayon of 100 denier and under.

Having thus fully disclosed the preferred embodiment of my invention, I claim:

1. An automatically threading loom shuttle.

having a cavity for a filling carrier, a threading block having a longitudinally extending thread passage in alignment with said cavity, and a tension device in said thread passage, said tension device comprising a pair of opposed friction members extending transversely of said thread passage said members being laterally movable in relation to each other 4throughout their lengths and yieldingly pressed together for exerting a slip-grip upon the running filling thread, said tension device being open at one end to thereby provide a thread entrance, yielding means pressing against one of said friction members, a second yielding means pressing against the other of said o0 friction members, said second yielding means being spaced longitudinally of said members from said first yielding means, and means for adjusting the tension of said yielding means. 2. 'Iyhe combination in a shuttle having a longi- 'tudinal threading slot, of two friction members having contacting friction faces, means located adjacent the top of -said slot for movably supporting said-members, an adjustable abutment extendingl transversely of said slot adjacentl the 10 lower end thereof, an adjustable tension member located on one side of said friction members and pressing said friction members against Isaid abutment, a second adjustable tension member located on the other side of said friction members 75 and pressing said friction members away from said abutment, said second named tension member being located substantially twice the distance from said abutment as said first named tension member.' whereby said friction members exert a substantially uniform force against each 5 other throughout their length.

3. The combination in a shuttle having a threading block therein, said block having a longitudinal threading slot. of two friction members having contacting friction faces for tensionl0 -ing the running lling thread therebetween, means` located adjacent the top of said slot for slidably supporting said members, an adjustable member extending transversely of said slot adjacent the lower end .thereof for supporting said 15 friction members, an abutment carried by said adjustable member against which the lower ends of said friction members rest, a pair of'coiled compression springs for pressing said friction members together, one of said springs being lo- 20 cated a greater distance above said abutment than the other whereby said friction members are pressed together with substantially a uniform pressure throughout their length.

4. 'I'he combination in a shuttle having a longi- 25 tudinal threading slot, of two friction plates having contacting friction faces, means located adjacent the top of said slot for movably supporting said plates, adjustable means located adjacent the bottom of said slot for supporting said plates 30 and adjusting said plates laterally in relation to the walls of said slot, vertically spaced yielding means intermediate said supporting means forl pressing said plates against each other and causing the latter to exert a substantially uniform 35 slip-grip on the running filling, and means for adjusting the tension of said yielding means.

5. A n automatically threading loom shuttle having a threading slot therein and also having a pair of oppositely disposed recesses adjacent its 10 upper edge, said recesses opening into said slot,

a pair of plates having contacting friction faces for tensioning the running lling therebetween, each of said plates having a guide lug at its upper end projecting into one of said recesses for slid- 45 ably suspending said plate in said threading slot,

an adjustable member extending transversely of said slotadjacent the lower end thereof for supporting said plates, said member having an abutment contacting the lower end of one of said 5 plates whereby said ends may be adjusted in relation to the side wallsof said slot, an adjusting screw having resilient means on its forwardA end for pressing one of said plates against theother, and a second adjusting screw having re- 55 silient means on its rearward end for pressing, the other of said plates against the plate contacted by said iirst named resilient means, the points of contact of said resilient means with said plates being located at different distances 00V above said `abutment whereby said plates are pressed' together with a substantially uniform tension throughout their length.

6. An automatically threading loom shuttle having a cavity for a filling carrier, a threading 55 block having a longitudinally extending thread passage in alignment with said cavity and also having a pair of oppositelydisposed recesses adjacentl its upper edge opening into said thread passage, and a tension device in said thread passage, said tension device comprising a pair of friction members, each of said friction members having a hole adjacent its bottom end and having a guide lug at its upper end projecting into one of said recesses, a screw threaded into said threading block adjacent the bottom of said thread passage, said screw having a pin projecting from one end thereof and extending through said openings in said friction members for supporting said members, the inner face of said screw forming an adjustable abutment whereby said friction? members are laterally adjustable in relation to the side walls of said thread passage, a compres-'L sion spring positioned behind each friction member for yieldingly pressing said members together to exert a slip-grip upon the running filling thread, said springs being spaced vertically from each other, and a pair of adjusting screws threaded into said threading block for adjusting the tension of said springs. j

HORACE H. BURDE'I'I.

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