US1860072A - Tensioning device - Google Patents

Description

May 24, 1932. c. A. BRAUDES mnsxonme DEVICE Filed April 24. 1929 INVENTOR a'ammAJ/amk;

El i loops being formed, of course,

Patented May 24, 1932- steers cmmcn A. alumnus. orsaooxnrn, as man nmsronm'e DEVICE Application filed April 24,

The present invention is concerned with a yarn or thread tenslonlng device WhlCh may have a wide range of. utility wherever an 1n- -tcrmittent or constanttension on a thread is desired.

It'is peculiarly applicable, however, for use in connection with a looping and tufting machine of the character in which a needle having an eye therein carries a bight of thread through a fabric in one direction, and as the needle is withdrawn that portion of the bight between the needle and the source of thread supply must be withdrawn with the needle leaving a loop on the siu'face of the fabric formed by only a portion of the thread which was carried through by the needle.

In machines of this character, in the absence of some mechanism for definitely tensioning the thread so that part of it will be drawn back with the needle, the needle will withdraw, leaving two loops of thread, these by the folding of the two sides of the bight on opposite sides of .the needle eye.

Obviously, the formation of such a double loop is undesirable since neither of the loops will be properly anchored to the fabric and furthermore the loops would be of non-uniform size. In addition, in the absence of some tensioning means the thread would tend to bunch around the needle as the latter was withdrawn, forminga lump on the fabric surface and possibly breaking the thread as the needle withdraws.

In accordance with the present invention abovenoted difiiculties are overcome and any possibility of double loopformation, bunching or lumping of the thread or breaking of the thread is avoided.

a The needle moves through the fabric carrying a bight of thread of considerably greatsize on the face of the 1928. Serial No. 857,622.

the fabric as the needle recedes. In most instances the end of the other portion of the bight' which lies most closely adjacent the needle eye will also be withdrawn and the remainder of such side of the bight folded upon itself to form a loop of the required fabric after each recipe rocation of the needle. The invention may be applied to looping and tufting machines, embroidering mano chines,rug-making machines and all other machines wherein individual threads are used, regardless of whether such machinery is of the single needle-type or employs a battery of needles operating either independentas ly or in unison and regardless of whether the tension on the thread is to be a constant tension or is to be intermittently applied.

Whether ornot cutter mechanismjis used to cut the loops and form a pile fabric is immaterial to the present invention, although the tension device may efiiciently serve to sustain the thread against being drawn through the fabric by the cutter, that is to say, the cutting operation may be convenvs iently performed during the time that the thread is tensioned. l

Other and more general objects of the invention are to provide a device of the character noted above and which is of extremely '80 simple, practical construction, which will be rugged, durable and efficient in use and well suited to the requirements of economical manufacture.

With the above noted and other objects in view, the invention consists in certain novel features of construction and combinations and arrangements of parts which will be more fully hereinafter described and pointed out in the claims. V0

The invention may be more fully understood from the following description in-con nection with the accompanying drawings, wherein: i

Fig. 1 is a vertical sectional view through that portion of a looping and tufting machine which embodies the invention.

Fig. 2 is a view generally similar to Fig. 1, but showing the needle and carriage in their uppermost instead of their lowermost posie mo line 3-3 of Fig. 1.

5 The drawings in the present case omit all showing of the portions of the machine which are non-essential to the invention, although reference may be had to my copendmg application Serial N 0. 454,469, filed May 21st, 1930, for a more complete understanding of the general nature of this type of machine.

The illustrated machine is of the character in which the fabric to be operated upon is supported in any suitable manner anda bight of yarn is carried upwardly through the fabric, then. partially withdrawn so that a loop is; formed upon the top of'the fabric within viewof. the operator and any inaccuracies in the'loop formation may be readily observed. and corrected. represents the fabric support of'anysuitable type, usually a1 table-upon which the fabric 11 is retained. The support is provided with a needle opening-12 through which the needle 13 carrying-the yarn 14 may move upwardly through the support and the fabric thereon, forming a series of loops 140 on the upper surface of thefabric. Showing of the means for feedingathe fabric transversely of the plane of theneedle; movement has been omitted.

The needle 13 is mounted on a carriage block 15 having a hollow pendent extension 16 guided. for vertical reciprocating movement in. a bearing sleeve 17 formed at the and of a-bracket 18' bolted orotherwise secured at 19 .to theunderface of the table 10.

v. meansfor imparting a vertical reciprocatingmotion to the carriage block 15 my: assume-many forms and constitute no paa'tiof :the present invention.

I have illustratively shown, however, a carriage reciprocating mechanism consisting offs-mock. shaft-2.0 carrying-"a yoke 21- straddling a' col-lar 22- fixed'upon the needle car- 5 stage extension 16 and operating to vertical- 1yre'ciprooate the carriage as the shaft is'rocked or "oscillated.

Thexyarn 14 after-beingthreaded through the needle passes downwardly througlr a relatively: restricted yarn guide passage 23in thooarriage-block 15, thence-through thehollowcarriage extension 16 and from the bottomof this carriage to the spool or other aourca-ofsupply.

It will be seen that as theneedle carriage moves upwardly in the position of Fig. 2 a baght of yarn is' ca-rried upwardly through thefabric,-. this bightbeing (2 siderably longer than the proposed loop/ The purpose-of" my improved tensioning means in the-present case is to grip the yarn at a point between vthe lreed'le-and the source of supply and cause-the portion ofthe bight lying between theneedle eye and the source of supplyto bewithdrawn through the fabric as the needle is retracted to the position of Fig. '1, the other portion of the bight folding over to form the loop.

I have shown a very sim 1e form of mechanism for accomplishmg t is result, including a plunger 24 normally held in retracted position by coiled spring-25 but ada ted to be projected at proper intervals by t e cam 26 and in projected position serving to clamp the yarn against the wall of the yarn guide 23. Yarn tensioning or clamping plunger 24 is caused to move into yarn gripping position as the needle starts on its downstroke and is released as the needle starts on its upstroke, whereby the yarn runs freely through the guide 23 on the upstroke of the needle and is held against movement on the down stroke.

The plunger carries a guiding collar 27 travelling in a. transverse cylindrical bore 28 in the carriage block. The reduced ortion 29 of this bore communicates with t e passage- 23 and provides a shoulder a ainst which the plunger retracting spring 25 ears,

this spring encircling the plunger between the shoulder and the collar 27. The other end of the bore 28 is closed by a plug 30 providing agui-de bearing for the end of the plunger.

The cam 26 is mounted upon the squared intermediate portion 31 of a transverse shaft 32 mounted in cars 33 extending laterally from one side ofthe carriage block.

The cam 26 is allowed limited endwise sliding movement over the squared intermediate port-ion 31, the shaft 32 beingretained against endwisemovement by the provision of collars 34 on the ends of the shaft. This sliding movement may be just enough to permit slippage between a circular extension 35 extending laterally from the cam and a circular tapered pocket 36 in one face of gear 37 free to turn on the shaft.

A coiled tensioning spring 38 encircles the shaft 32- between the cam 26 and a tension adjusting nut 39' and tends to urge the cam into frictional engagement with the gear 37.

This gearis constantly inmesh with a rack 40 fixed in upright position upon the bracket 18, and as the needle carriage reciprocates the gear is'alternately rotated in opposite directions by the rack.

The high side 41 of the cam 26 coacts with the-end of the plunger 24and rotary movement of the shaft 32 and its fixed cam is limited by a pair-of pins 42 projecting from one of the ears'33.

The operation of the device is as follows: The needle carriage in Fig. 1 has reached the limit of its downward movement. As it starts to move upwardly the gear 37 starts to turn under-the influence of the rack, and since the cam is frictionally clutched to the gear, cam projection 41 will immediately move out of engagementwith the plunger 24, permitting this plunger tobe retracted under the influ- '20 over the other side ence of s ring 25 and relieving tension on the yarn. e rotary motion of the cam is very' I slight, since as soon as the projection 41 engages the upper pin 42, the cam will slip relatively to the gear for the remainder of the upward motion of the carriage.

As the needle moves upwardly through the fabric as shown in Fig. 2, a certain amount of yarn will be drawn upwardly and the large 10 bight will be formed. As soon as the carriage starts on its downward movement however, the direction of rotation of the gear 37 will be reversed, the cam projection will move against the plunger 24, thereby forcing the plunger into yarn clamping position and causing that portion of the bight which is located between this plunger and the eye of the needle to be retracted through the fabric as the needle carriage descends, and folding the bight to form a loop of accurately predetermined size upon the upper face of the fabric.

What I claim is:

1. As a new article of manufacture, a needle carriage and a movable thread tensioning device mounted thereon, means for operating said thread tensioning device comprising a gear on the needle carriage coacting with a stationary rack as the carriage reciprocates,

a cam frictionally clutched to the gear, means to limit the friction impelled movement of the cam and means whereby the position of the cam controls the operativeness or inoperativeness of the tensioning device.

2. In a tensioning device of the character described, a reciprocable needle carriage, a thread guide, and thread tensioning means for restraining the thread against movement in its guide, said means including a fixed memher mounted below the machine table and operable by movement of the needle carriage to eriodicall tension the thread;

igned at ew York, in the county of New York and State of New York this 15th day of April, A. D. 1929.

CLARENCE A. BRAUDES.

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