US2419419A - Letoff mechanism for looms - Google Patents

Description

April 22, 1947. 4 o v, PAYNE v 2,419,419

LET-OFF MECHANISM FOR LOOMS Filed Sept; 8, 1945 2.Sheets-Sheet 1 INVENTQR 05cm; v. PAYNE AT TORNEY P 1947- v o v PAYNE 2,419,419

LET-OFF MECHANISM FOR. LOOMS Filed Sept. 8, 1945 2 Sheets-Sheet 2 .INVENTOR OSCAR V. PAYNE WWW/W17.

AT TORNEY Patented Apr. 22, 1947 2,419,419 LETOFF MECHANISM FOR LooMs Oscar V. Payne, Leicester, Mass, assignor to Crompton & Knowles Loom Works, Worcester, Mass, a corporation of Massachusetts 8, 1945, Serial No. 615,124

Application September 7 2 Claims.

This invention relates to improvements in letoff mechanisms for looms and it is the general object of the invention to provide means by which the warp beam can be manipulated without interference on the part of the weight which tensions the warp.

In a type of letoff already proposed by me the warp beam has secured thereto an arcuate guide for the chain of a weight which acts normally to move the warp beam in a backward direction. A worm and worm gear operate to change the angular relation of the arcuate guide with respect to the beam so that the weight will move through only a short range of motion as the warp thread is consumed during the weaving operation. In that letoff the arcuate guide is at the back of the warp beam and the weight and its chain have been located rearwardly of the loom in a position where they project into the aisle utilized in changing the warp beam. It is an important object of my present invention to locate the arcuate guide on the forward part of the beam structure so that the weight can be in front of its former position and not interfere with the placing of a new warp beam into the loom.

The letoff mechanism shown in the earlier structure to which I have referred is so constructed that the warp beam is swung angularly around one of its ends prior to removal of the loom. When the weight depend-s from the arcuate guide as in such a letoff it interferes with the angular movement of the beam and is in such position as to interfere with the workmen who are manipulating the beam. This is particularly true of beams of large diameter. It is another object of my present invention to utilize the previously employed pivotal mounting for one end of the beam but locate the arcuate guide in such position that the weight will neither interfere with the removal of the beam nor.undergo movement as the beam is turned angularly preparatory to removal of the loom. These results I obtain by leading the weight supporting chain upwardly from the arcuate guide on the front of the beam structure and over guide pulleys moving about axes fixed with respect to the loom and then downwardly to the weight. The latter remains more or less stationary when the beam is being turned angularly and will not swing, thereby avoiding risk of injury to the workman.

With these and other objects in view which will appear as the description proceeds, my invention resides in the combination and arrangement of parts hereinafter described and. set forth.

In the accompanying drawings, wherein a convenient embodiment of my invention is set forth,

Fig. 1 is a side elevation of a loom having my invention applied thereto,

Fig. 2 is a rear elevation looking in the direction of arrow 2, Fig. 1

Fig. 3 is a plan view looking in the direction of arrow 3, Fig. 2,

Fig. 4 is a detail of part of the structure used with my invention, particularly that part which carries the arcuate guide,

Fig. 5 is an enlarged horizontal section on line 5-5 of Fig. 2, and

Fig. 6 shows a modified form for transmitting force from the weight to the arcuate guide.

Referring particularly to Fig. 1, I have shown a loom frame I0 and a lay sword II which reciprocates backwardly and forwardly during loom operation. Extending rearwardly from the loom is a bracket 12 bolted to a stand l3 on the floor and having at the upper end thereof a bearing member I4. The warp beam I5 is provided with a gudgeon I6 and supplies warp W which passes over a whip roll H and then forwardly to the weaving instrumentalities. The bearing [4 supports an outer ball race 18 having a concave surface engaging ball bearings I8 which in turn engages a crowned or convex bearing ring 20 held to a sleeve 2| through which the gudgeon l6 passes.

Mounted on the sleeve 2| is a casing 25 in which turns a shaft 26 carrying a worm 21 meshing with a worm wheel 28 fixed with respect to the gudgeon l6 and turning with the warp'beam. The mechanism for turning the shaft 25 comprises an arm 3| extending rearwardly from the lay to a lever 32 pivoted as at 33 to a fixed part of the loom. The upper end of lever 32 is pivoted to a rearwardly extending connector 34 attached to a rocking lever 35 pivoted on a stationary support, such as the stand 13. During loom operation reciprocation of the loom sword ll causes rocking of lever 35 and movement of its upper arm 35 toward and from the casing for engagement with a sliding rack 31. The latter operates ratchet wheel 38 which drives a clutch 39 fixed to shaft 25, causing turning of the latter.whenever the rack is operated by the lever 35.

When the casing turns to the right as viewed in Fig. 4 the rack comes within the range of operation of lever 35 and a backward movement of the casing relatively to the beam results. For further details of the mechanism which controls shaft 26 see particularly Fig. 3 of my prior Patent No. 2,062,725.

The matter thus far described may be very similar to the letoif mechanisms shown in my prior patent already mentioned and also No. 1,803,143.

In carrying my present invention into effect I provide an arcuate guide 45 secured as at 46 to the casing 25 and grooved as at 41 to receive a chain 48 the lower end of which is attached as at 49 to the arcuate guide. The chain extends upwardly from the guide to an idler pulley 50 turning on a stationary stud on a stand 52 secured to the loom frame. The chain leads vertically upwardly from the idler pulley 50 to a guide pulley 53 turning on a stud 54 on a fixed stand 55. The chain is trained around the upper part of a guide pulley and then leads downwardly to a variable weight 5% which is located preferably in front of the axis of the warp beam and to one side of the loom.

. During normal loom operation the warp is consumed and rack 3'! and ratchet wheel 38 periodically move the casing 25 rearwardly or in a counter-clockwise direction as viewed in Fig. 1 with respect to the beam as already set forth. The casing 25 will move through a slight range of angular motion depending upon the extent to which the arm 36 moves the pawl .31 and the weight rises and falls during this periodic adjustment between the beam and the casing 25 and constantly exerts a force on the warp beam transmitted through the worm and the worm wheel tending to turn the warp beam in a countier-clockwise direction as viewed in Fig. 1 to hold the warp W under tension.

When the exhausted warp beam is being removed from the loom there is no warp tension to prevent weight 56 from causing counter-clockwise movement of the beam as viewed in Fig. 1 and the casing 25 would turn backwardly except for a ratchet Bil cast on the casing 25 in position for cooperation with a hold pawl 6| connected to a forwardly extending rod {52 accessible from the front of the loom, see Fig. 4, and prior Patent No. 1,803,143. It may not be necessary in all instances to use the ratchet Bil, since the arcuate guide 45 is so located that weight 56 can rest on the floor to one side of and in front of the beam where it will not interfere with manipulation of the beam.

That end of the beam opposite to the end shown in Fig. 1 is then disconnected from its bearing pocket not shown and swung rearwardly, a condition which is permitted by reason of the ball bearing shown in Fig. 5. During this angular movement of the beam with respect to the loom the arcuate guide 45 will move angularly with the beam, but because of the idler and guide pulleys the weight will remain in a substantially fixed position and will not move angularly with the beam or the casing 25. The weight will also be in a position where it will not interfere with removal of the beam. In my previously mentioned patentsthe weight under these conditions would have moved with the beam and there would have been risk of injury to the workman due to the swinging of the weight.

Fig. 6 shows a modified means of transmitting force from the weight to the casing 25 wherein the guide pulley 53 is replaced by a lever 19 moving about a pivot "H which may be the same as the axis 54 for the guide pulley 53. One end of the lever in is connected as at 12 to a cable or chain 13 which extends down to the weight d5, while the opposite end of the lever is connected as at 14 to a depending chain 15 connected to the arcuate guide 45. The lever ends or arms (6 and i7, respectively, are of unequal length as shown in Fig. 6 to permit the use of a smaller weight than is possible when the guide pulley 53 is employed.

From the foregoing it will be seen that I have provided simple means by which a weight constantly exerts a rearward force on a warp beam but is so located as not to partake of any angular or swinging movement when the warp beam is swung about its ball bearing mounting shown in Fig. 5 preparatory to removal from the loom. It will further be seen that the weight is located forwardly of the rear part of the warp beam and therefore is out of the aisle behind the loom and is also in such position that even though it should swing slightly it will not be able to injure the workman removing the beam. Furthermore, the lever It! has arms of unequal length which permit the use of a lighter weight than when the guide pulley 53 is used.

Having thus described my invention it will be seen that changes and modifications may be made therein by those skilled in the art without departing from the spirit and scope of the invention and I do not wish to be limited to the detailsherein disclosed, but what I claim is:

1. In letoff mechanism for a loom having a warp beam which rotates in a forward direction to supply warp for the weaving operation, an arcuate guide extending forwardly from the warp beam and operatively connected thereto, a guide pulley mounted on the loom frame above said arcuate guide and rotatable about an axis substantially parallel to the axis of the beam, a second pulley above the first pulley rotatable on the loom about a horizontal axis substantially at right angles to the axis of the first pulley, said second pulley being of such diameter that one side thereof extends beyond the end of the beam with respect to the longitudinal center of the beam, a flexible member connected at one end thereof to the arcuate guide and extending upwardly along the first pulley and over the second pulley and having the other end thereof depending from said one side of said second pulley, and a weight connected to said other end of the member, said weight effective to exert a force through the member and along said pulleys to the arcuate guide in a direction tending to cause reverse rotation of the warp beam.

2. In letofi mechanism for a warp beam rotatable about bearings one of which is so constructed as to permit the warp beam to be swung angularly rearwardly with respect to the loom about said one bearing when the beam is being removed from the loom, an arcuate guide operatively connected to and moving with the warp beam when the latter moves angularly about said one bearing, said arcuate guide moving angularly about the axis of the beam during loom operation, a guide pulley above said beam rotating about an axis substantially parallel to the axis of the beam during loom operation, a second pulley above the first pulley moving about a horizontal axis substantially perpendicular to the axis of the first pulley, a flexible member having one end connected to said arcuate guide and extending upwardly therefrom and along said pulleys and having the other end thereof depending from the second pulley, and a" weight: connected 5 6 to said other end of the member and depending TEN freely from said second pulley and remaining UNITED STATES PA TS substantially stationary during angular move- Number Name Date ment of the beam horizontally about said one 2,169,326 Payne Aug. 15, 1939 hearing. 5 2,305,422 Herard Dec. 15, 1942 OSCAR V. PAYNE. 1,574,724 Zahn Feb. 23, 1926 REFERENCES CITED FOREIGN PATENTS Number Country Date The following references are of record in the 10 320,252 Italian Aug. 11, 1934 file of this patent: 659,569 French Aug. 27, 1928

Images