US2306287A - Thread cutting mechanism for looms - Google Patents

Description

R. G. TURNER 2,305,287

THREAD CUTTING MECHANISM FOR LOOMS Filed April 15, 1942 j fi? INVEN-roR Rlcl-mnb G=TuRNER ATTORNEY Patented Dec. 22, 1942 UNITED STAT S FTET OFFICE THREAD CUTTING MECHANISM FOR LOOMS Application April 13, 1942, Serial No. 438,780

9 Claims.

This invention relates to improvements in weft thread cutters for looms and it is the general object of the invention to provide two cutting edges, one on the shuttle behind the thread and the other in front of the thread, to be operated by forward motion of the shuttle.

At the time of weft replenishment a thread extends from the depleted bobbin through the shuttle delivery eye and along the front shuttle wall to the adjacent selvage. It is desirable to cut this thread as near the delivery eye as possible so that the outgoing depleted bobbin will unthread the delivery eye. This general result is accomplished by the mechanism set forth in prior Patent No. 1,881,920 wherein the front shuttle wall is provided with a smooth plate across which the thread extends and in position to cooperate with a cutting edge mounted in front of the lay. It is an important object of my present invention to provide the cutting plate with a series of cutting edges along which the cutter slides to cut the thread as the lay approaches front center on replenishing beats of the loom.

It is another object of my present invention to provide the front wall of the shuttle with a plate having diagonal spaced cutting edges formed on ribs the top surfaces of which are beveled to insure contact between the diagonal cuttin edges and the cutter blade.

It is a more specific feature of my invention to provide cutting mechanism of the type already described wherein the angle of the diagonal cutting edges bears such a relation to the height of the thread cutter that the latter engages only two of the diagonal ridges at a time for the pur pose of allowing the thread cutter to adjust itself on its pivot with respect to the plane determined by the two edges which it engages.

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 drawing, where three forms of my invention are set forth,

Fig. 1 is a front elevation of a shuttle and thread cutter made according to the preferred form of my present invention, together with cer tain adjacent mechanism,

Fig. 2 is a horizontal sect-ion on line 2-2 of Fig. 1,

Fig. 3 is an enlarged horizontal section similar to a part of Fig. 2,

Fig. 4 is an enlarged vertical section on line 4-4 of Fig. 2,

Fig. 5 is a diagrammatic front elevation on an enlarged scale of the plate and cutter blade shown in Fig. 1,

Fig. 6 is a view similar to Fig. 1 but showing the first modification of my invention wherein the shuttle carried'cutting edges are vertical,

Fig. '7 is a view similar to Fig. 2 but showing the second modification of my invention wherein the single cutter is on the shuttle,

Fig. 8 is a front elevation of the shuttle carried cutter shown in Fig. '7, and

Fig. 9 is a rear elevation of the front cutter shown in Fig. 7.

Referring particularly to Figs. 1 and 2, I have shown a loom lay L provided with a shuttle box B to receive a shuttle S containing a weft bobbin W; The right end of the shuttle as shown in Fig. 2 is provided with athread passage HI leading to a delivery eye l the forward end of which preferably communicates with the groove l2 extending longitudinally along the front wall I3 of the shuttle. The groove is not necessary but does assist in proper tensioning of the weft thread. As the weft thread T is unwound from the bobbin it extends through the passage Ill, through the delivery eye II, and then leads to the left for attachment to the adjacent selvage. It is to be understood that the shuttle box shown in Figs. 1 and 2 is located at the right hand end of the loom and will be provided with a shuttle binder l5.

An arm 20 is pivoted as at 2| on a fixed support 22 and is normally urged rearwardly by a torsion spring 23 as indicated in Fig. 2. The lever 2!] ordinarily has the right end thereof held in forward position by engagement of its left end by a part 24 of the transfer mechanism of the loom not shown. On a replenishing beat the part 24 moves forwardly to allow the spring 23 to move the right end of lever 20 rearwardly from its normal position. A cutter blade 25 having a cutting edge 26 is pivoted as at 2'! to a stem 28 held in angularly adjusted position in bearing 29 on lever 20 by set screw 30. Cutting edge 26 is located to the rear of pivot 2| so that it moves to the right when moved forwardly by the advancing shuttle.

The matter thus far described, except for the forms of the cutting mechanism to be described hereinafter, may be the same as that set forth in the previously mentioned patent. Under normal conditions the lay L moves back and forth in the loom and the transfer mechanism not shown holds the lever in forward position with the cutter blade in non-cutting position. On replenishing beats of the loom, however, lever 20 swings rearwardly to project the cutting edge 26 into the path of the advancing shuttle and the latter engages blade to move it forwardly and also to the right.

In carrying the preferred form of my present invention into effect I provide the front wall l3 of shuttle S with a plate 33 having a series of diagonal cutting ribs or ridges separated by grooves 36. The tops of the ribs are flat and each has a cutting edge 31 at the left hand side thereof as viewed in Fig. 5. The forward surfaces of the ribs may be ground to provide the cutting edges 31 a single grinding operation in which case the surfaces 40 lie in a plane.

In operation, the thread T extends across the plate 33 to have contact at spaced intervals with the ribs. So long as there is suificient weft for continued weaving the cutter blade 25 is in forward position with its edge 26 vertical in the preferred form, but when a replenishing operation occurs the blade will be moved rearwardly so that its cutting edge 26 will occupy some such position as that indicated by the single line 26 in Fig. 5. As the shuttle moves forwardly it will cause the ribs 35 and thread to move against the cutting edge 26. During subsequent advance of the shuttle the cutter 25 will slide along the ribs to the right, Figs. 2 and 5, to assume some such position as 26a in Fig. 5. The sweep of the blade along the plate is sufficient to cause the thread T to be cut by the cutting edge 26 by at least one of the ribs whether the thread be engaged by the upper or the lower part of the cutting edge 26.

In the first modification shown in Fig. 6 I provide the shuttle with a plate having vertical ribs 46 the left edges of which have cutting edges 41. The top surfaces 48 of ribs 46 are beveled, being inclined rearwardly in the direction in which the cutter 25 moves during the cutting operation. In this form of the invention the stem 28 is turned in bearing 29 so that the cutting edge 26 is oblique to a vertical line, thus assuming a diagonal relation with respect to the vertical cutting edges 41. It will be noted that as the thread passes from the delivery eye to the left it approaches the lower edges 49 of the inclined surfaces 48 and leaves the cutting edges 41.

Because of this relation of the direction of inclination of the surfaces 48 with respect to the direction in which the weft thread moves there is little likelihood that the ribs 46 will cut the thread. I find in fact that there is very little likelihood that the thread will be cut when the tops of the ribs are made asin the preferred form of the invention.

' In the second modification the single cutting edge is on the shuttle while the cutting ribs are on stem 28. As shown in Fig. 8 the shuttle S has a plate 56 on its front wall, and a single cutter blade 5| with a cutting edge 52 extends diagonally across the plate. The cutter 25 is replaced by a cutter head or member 55 pivoted to stem 28 and having a series of spaced vertical ribs 56 with cutting edges 51, as shown in Fig. 9. The ribs 56 need not necessarily be vertical nor blade 5| oblique, so long as the diagonal relation suggested in the first two forms of the invention is preserved.

The action of these modifications is similar to that described for the preferred form. In each form a single blade has sliding engagement with "a set of cutting edges diagonal to it to cut the thread leading from the shuttle. In practice it is probable that only one of the series of ribs cooperates with the single cutter in the actual cutting of the thread, but the shuttle is subject to slight variations in its position and for this reason it is desirable that a series of ribs be used to widen the range of operation of the cutting mechanism.

A refinement of my invention concerns the relationship between the height of the cutting edge 26 and the angle of inclination of the ribs together with their spacing. This relationship may exist for all forms of the invention, but I will describe it in connection with Fig. 5, where it will be seen that when the lower part of the cutting edge 26 engages one of the ribs its upper end will engage the next rib to the right, but will not engage a third rib. As the cutting edge 26 assumes successive positions to the right it will move entirely clear of the first rib before engaging another rib. The result of this relationship is that the cutting edge 26 has engagement with but two ribs at a time and if adjacent cutting edges on the plate should not be exactly parallel, the blade 25 can adjust itself to move into the plane determined by the cutting edges which it engages, due to pivotal connection 21. While the relationship just described is desirable I have found in actual practice that the cutter will operate satisfactorily if the blade 25 engages three ribs at a time.

From the foregoing it will be seen that I have provided a simple form of weft thread cutting mechanism wherein two cutting edges diagonally disposed to each other cooperate to cut the thread near the shuttle delivery eye. Experience shows that the type of plate set forth herein will cut threads of large diameter such as are not always satisfactorily cut when the plate has a flat surface as set forth in the prior art. It will also be seen that if desired, the relation between the height of the single cutting edge, the angle of the ribs, and their lateral spacing, can be such that the cutting part on stem 28 will never engage more than two ribs at a time and can therefore adjust itself to lie in the plane of two adjacent cutting edges on the cooperating plate. As stated hereinbefore, however, this is not an essential feature. It will also be noted that the top surfaces of the ribs can be inclined to improve the cutting operation and that the direction of inclination is such as to minimize risk of cutting the thread.

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 details herein disclosed, but what I claim is:

1. In thread parting mechanism for a loom having a lay and a shuttle movable forwardly with the lay, means on the shuttle defining a cutting edge across which the weft thread from the shuttle extends, and a weft parter operated by forward motion of the shuttle and having a cutting edge diagonal with respect to the cutting edge on the shuttle to slide along the latter in contact therewith to part the weft thread.

2. In loom thread parting mechanism having two cooperating thread cutters one of which is on a shuttle behind the shuttle weft thread and one of which is mounted in front of the thread, one of said cutters comprising a series of spaced cutting edges to cooperate with the cutting edge of the other cutter, and means operated by forward motion of the shuttle to cause the cutting edge of the other cutter to engage the elements successively during th thread parting operation to part the thread.

3. In thread parting mechanism for a 100m operating with a shuttle having a thread extending therefrom, two cooperating cutting members one of which is on the shuttle behind the thread and one of which is in front of the thread, means to mount one of said members so that the cutting edge thereof is diagonal with respect to the cutting edge of the other member, and means operated by forward motion of the shuttle to cause a point of engagement between the cutting edges of said members to move along said edges during a thread parting operation to part the thread.

4. In loom thread parting mechanism having two cutter members one of which is on a shuttle behind the weft thread and one of which is in front of the thread and wherein forward motion of the shuttle causes the cutter members to move in sliding engagement with each other with the thread between them to part the thread, one of said cutters comprising a series of spaced cutting edges and the other cutter having a cutting edge which is diagonal to said cutting edges as the cutters move with respect to each other during the thread parting operation.

5. In loom thread parting mechanism having two cooperating thread cutters one of which is on a shuttle behind the thread and one of which is in front of the thread and wherein forward motion of the shuttle causes relative sliding engagement of the cutters during a thread parting operation with the thread between them, one of said cutters comprising a series of spaced cutting edges extending transversely of the thread at a given angle with respect to the thread and the other cutter having a cutting edge also extending transversely of the thread but at a different angle with respect to the thread to have progressive engagement with the cutting edges of said series as said cutters have relative sliding engagement.

6. In thread parting mechanism for a 100m operating with a shuttle having a thread extending therefrom, two cooperating cutter members,

one on the shuttle behind the thread and the other in front of the thread, one of said members having a series of spaced thread cutting edges, the other cutter having a cutting edge to cooperate with said series of cutting edges, and means operated by forward motion of the shuttle to cause the cutting edge of said other cutter to have progressive sliding engagement with the cutting edges of said series in a direction diagonal to the latter to part the thread.

7. In thread parting mechanism for a loom operating with a shuttle having a thread delivery eye, means on the shuttle to provide a series of spaced cutting edges behind and extending transversely of the thread, a cutter in front of the thread having a cutting edge to cooperate with cutting edges on the shuttle, and means operated by forward motion of the shuttle to cause the cutting edge of said cutter to slide across the cutting edges on the shuttle to engage said edges progressively and part the thread.

8. In loom thread parting mechanism comprising a plate on a shuttle behind the thread extending from the shuttle, a series of thread cutting ribs on said plate across which the thread extends, a cutter in front of said plate having a cutting edge diagonal with respect to said ribs, and means operated by forward motion of the shuttle to move the said cutter across said ribs and maintain the cutting edge of said cutter diagonal with respect to said ribs during the thread parting operation.

9. In loom thread parting mechanism comprising two cooperating cutter members one of which is mounted on a shuttle behind the weft thread extending from a delivery eye of the shuttle and one of which is in front of the thread, one of said cutter members comprising a series of spaced cutting elements and the other cutting member having a cutting edge diagonal with respect to said elements, and means to move said member relatively and in engagement with each other in a direction oblique to said elements to part the thread, said cutting edge and cutting elements being so related that said cutting edge engages but two elements at a time.

RICHARD G. TURNER.

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