US1726154A - Sewing machine - Google Patents

Description

Aug. 27, 1929. J. KlEWlCZ SEWING MACHINE 4 Sheets-Sheet 1 Fil'ed Oct. 1928 lnv en1o r. John Klevwcz 97% Win;

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Inventor. John Kiewlcz.

by H Lid. 111mm Aug. 27, 1929. J. KIEWICZ 1,726,154

SEWING MACHINE Filed Oct. 1, 1928 4 Shets-Sheet 3 F183. "1L w a i w i I lnvenmrj John K iewi-cz 7% Warm A1 tys.

Aug. 27, 1929. J. KIEWICZ 1,725,154

SEWING MACHINE Filed 001:. 1, 1928 4 Sheets-Sheet 4 INVENTOR. v doc-m KIEWIGZ.

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Patented Aug. 27, 1929.

UNITED STATES PATENT OFFICE.

JOHN KIEWICZ, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO THE REEGE BUTTON HOLE MACHINE COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OF MAINE.

SEWING- MACHINE.

Application filed October 1, 1928. Serial No. 309,421.

This invention relates to sewing machines and particularly to sewing machines of that 6 type in which when the machine comes to rest a loop of needle thread will be engaged by the under thread mechanism and in which means are provided for cutting said loop and pulling the cut end out from the work.

One of the objects of my invention is to provide novel means for gripping the cut end of thread after it is pulled out from the Work and for holding said end while the first stitch of the next succeeding stitching operation is formed. 7

In order to give an understanding of the invention I have illustrated in the drawings a selected embodiment thereof which will now be described after which the novel features will be pointed out in the appended claims.

In the drawings, Fig. 1 is a side view of a sewing machine having my improvement applied thereto;

Fig. 2 is a front view; I

Fig. 3 is a fragmentary view on a large scale showing the construction of the upper thread pull-off and gripper;

Figs. 4 and 5 are side and rear views of the upper thread pull-off and gripper detached from the machine;

Fig. 6 is a diagrammatic view illustrating the operation of the thread cutter and pull-off;

Figs. 7 and 8 are fragmentary views illustrating the manner in which the thread gripper is actuated;

Fig. 9 is a fragmentary view illustrating the operation of the thread cutter;

Fig. 10 is a View illustrating the manner in which the thread is withdrawn 7 from the holder or gripper during the formation of the first stitch of a sewing operation.

The present invention is adapted for use in sewing machines ofdifierent types and for convenience I have illustrated it as it might be embodied in a buttonhole sewing machine. I wish to state, however, that its use is notlimit'ed to buttonhole sewing machines.

In the machine herein illustrated the stitch-forming mechanism, which comprises an upper needle 1, an under threadmechanism that may be either in the form of loopers, one of which is shown at 2 in Fig. 6, or may be in the form of a rotary hook and shut"- tle, is mounted ona frame 3 which in turn is carried by a bed frame 4. to which the work 5 is clamped by means of suitable work clamps In the particular construction herein shown the under thread mechanism'is in the form of loopers and loop spreaders which are carried by a turret 7 rotatably mounted in the portion 98 of the frame 3, provision being made as usual in sewing machines of this type to rotate the stitch-forming mechanism Ivlvliile sewing around the ends of the button- The machine herein illustrated is also provided with means for cutting the buttonhole slit, which means comprises two cutting elements 8 and 9,,one of which is a cutting blade and the other of which is a cutting block. The cutting element 8 is constructed as shown in my co-pending application, Serial N 0. 269,985, filed April 14th, 1928, it being carried by a block or slide 10 which is movably mounted on the portion 98 of the frame and which is given a movement at the proper time to bring the element 8 into proper position to out the buttonhole.

The cutting element 9 is shown as carried by the usual cutting lever 11 which is pivoted at 12 and which is provided with a tail portion 13 adapted to be engaged by a cam projection 14. formed on the main cam 15 by which the operations of the machine are controlled. This method of operating a buttonhole cutting lever is one which is commonly employed in buttonhole sewing machines and needs no further description, it being sufiicient .to say that at the proper time in the cycle of operations the rotary movement of the main cam 15 brings the cam projection 14 into position to engage the tail 13 thereby giving the lever 11 its rocking or, cutting movement.

Simultaneously with this cutting movement the block 10 carrying the cutting element 8 is given a forward movement to bring it into position to co-operate with the putting ele ment 9 and this forward movement is derived from the swinging movement of the lever 11, all as illustrated-and described in the abovementioned co-pending application. The block 10 is connected to a rod 16 which is slidably mounted in the bed 4 and this rod a cam surface 23 on the lever 18 and being provided at the other end with a lateral stud Y 24 adapted to be engaged by the rear end of the lever 11. When the lever 11 is operated and the left hand end in Fig. 1 is raised the lever 20 will be turned about its pivot 21 thereby causing the roll 22' to engage the lever or arm 18 and swing the latter forwardly, such forward movement giving the required movementto the block 10 and cutting element 8. As stated above this mechanism is similar to that illustrated in my co-pending application, Serial No. 269,985.

When the machine comes to rest at the end of the sewing operation the needle 1 is raised and the loop 25 of upper thread 26 is engaged by the under thread mechanism so that said loop 25 will be located below the usual throat 27 which is carried by the turret 7.

The sewing machine herein illustratedis provided with means similar to that shown and described in my above-mentioned copending application for cutting one leg of the loop 25 of needle thread after the machine has been brought to rest. This thread cutter is indicated at 28 and it is carried by the block 10 so that when the block is moved forward to present .the cutting element 8 in its proper position the thread cutter 23 will also be moved forward into a position to engage one leg of the loop 25 as shown in Fig. 6 and on the return movement of the block said cutter will sever the loop of needle thread.

The construction so far described is substantially the same as is illustrated in my above-mentioned copending application and forms no part of the present invention, which has special reference to means for engaging the upper thread between the needle and the work after the loop 25 has been cut and pulling the cut end back from the work, and also gripping or holding the cut end until the first stitch of the next sewing operation is being performed.

The pulling of the cut end of the thread out of the work is accomplished by a pull-0E arm 29 which is pivoted to the frame 3 at 60 andwhich swings transversely of the feeding movement of the frame. This arm is bent at its lower end to provide a horizontally-extending'foot portion 30 which is formed with a thread-receiving notch31. During the sewing the pull-off arm 29, which is situated immediately back of the needle 1, will occupy the full line position shown in Figs. 2 and 3. When the sewing operation has been completed, however, this pull-off arm 29 is swung into the dotted line position Figs. 2' and 3 to carry the foot portion 30 thereof to the left of the needle thread. The shape of the lower end of the pull-off arm and foot portion 30 is such that as the arm swings into the dotted line position said foot portion will wipe by the length of needle thread 26 extending from the needle 1 to the work and when the arm 29 position Figs. 2 and 3, just after the loop 25 1 of needle thread has been out and hence the operative movement of the pull-off arm will pull the cut end of upper thread back from the work.

The means for actuating the pull-off arm is similar to that shown in my co-pending ap-' plication Serial No. 269,985. The cutter lever 11 is provided with a forwardly-extending finger 32 which is situated above the pull-ofi arm 29. When the cutter lever is given its operative movement by the cam projection 14 the finger 32 is carrieddownwardly with the forward end of the lever and in its downward movement it engages the arm 29 and swings it into its dotted line position as shown in Figs. 2 and 3. When the cutter lever is raised the pull-off arm 29 is returned to the full line position through the medium of a spring 33.

The pull-off arm 29 has associated with it a resilient thread-gripping member 34 which is secured to the side of the arm 29 and is pro vided with a gripping foot portion 35 adapted to engage the under side of the foot portion 30. The resiliency of the member 34 normally holds it in its inoperative position shown in Figs. 5 and 8, in which position the gripping foot 35 will be retracted back of the thread-receiving notch 31. This is the position of the parts when the thread is picked up in the notch 31. As the arm 29 completes its operative thread-pulling movement into the full line position the member 34 is acted upon by a cam which forces it toward the arm 29 and carries the thread-gripping foot 35 across the notch 31 as shown in Fig. 7, whereby the thread is gripped between said foot 35 and the portion 36 of the foot 30.

The cam by which this operation is performed is indicated at 37 and it is in the form of an arm which is secured to the frame 3 and is so positioned that just before the pull-off arm 29 completes its thread-pulling movement the gripping member 34 will come into engagement with the cam 37 and during the final portion of said thread-pulling movement the engagement of the member 34 witlrthe cam surface 3? will force said member 34 toward the arm'29 to cause the threadgripping foot 35 to grip the thread as shown inFig. 7.

During the movement of the arm 29 from the dotted to the full line position, therefore, the cut end of the upper thread will be pulled back out of the work and said end will be gripped and held by the foot portion 35'of the thread-gripping blade.

This arm 34 will remain in the full line position shown in Figs. 2 and 3 while the sewing machine is at rest and until the buttonhole cutter is actuated for cutting the next buttonhole which occurs after the stitching has been completed. Hence when the stitching on the next buttonhole begins the end of the upper thread 26 is held in the thread gripper.

As the needle 1 makes its first penetrating thrust through the work 5 at the beginning of a seam as shown in Fig. the portion of the needle thread extending from the needle to the thread-gripping device will, of course, be placed under more or less tension which will tend to swing the pull-off arm 29 downwardly slightly.

As this occurs the pressure of the cam 37 against the member 34; will be eased off slightly thereby letting up somewhat on the gripping action on the thread although the thread will be held sufficiently to provide for the formation of the first stitch. As the stitching progresses and the frame 3 moves to the left Fig. 1 the end 38 of the thread will be completely pulled out from the gripper. As the strain on the thread end increases the swinging arm 29 will be pulled further downwardly thus still further eas'ing oil the gripping pressure on the thread until the thread has been completely pulled out from between the foot and the gripper 34. Hence at the end of the sewing operation the needle thread will be firmly held and the gripper will maintain its firm grip thereon until the sewing has begun on the next buttonhole and as the first stitch is being formed the gripping action on the thread is sufficient to hold it so that the first stitch will be properly formed but is eased up somewhat to allow the thread to be withdrawn from the gripper after the first stitch has been completed.

I claim:

1. In a sewing machine, the combination with stitch-forming mechanism including a needle operating from above the work and means to cut the needle thread beneath the work at the end of the sewing operation, of a pull-off arm adapted to engage the needle thread after it is cut and pull the cut end back from the work, and means carried by said arm for gripping the thread.

2. In a sewing machine, the combination with stitch-forming mechanism including a needle operating from above the work and means to cut the needle thread beneath the work at the end of the sewing operation, of a pull-ofl' arm adapted to engage the needle thread after it is cut and pull the cut end back from the work, a thread-gripping member carried by said arm, and means to actuate said member by the swinging movement of the arm to cause it to grip the thread.

3. In a sewing machine, the combination with stitch-forming mechanism including a needle operating from above the work and means to cut the needle thread beneath the work at the end of the sewing operation, of a pull-off arm adapted to engage the needle thread after it is cut and pull thecut end back from the work, a thread-gripping member carried by said arm, and a stationary cam member situated to be engaged by said gripping member during the swinging movement of said pull-off arm, whereby the gripping member is caused to grip the thread.

4. Ina buttonhole sewing machine, the combination with stitch-f0rming mechanism including a needle operating from above the work, of buttonhole-cutting mechanism, means to cut the needle thread beneath the work at the end of the sewing operation, a swinging pull-off arm to engage the needle thread after it is cut and pull it back from the work, means to actuate said arm by the buttonhole-cutting mechanism, and a threadgripping device carried by said arm for holding the cut end of the thread.

5. In a buttonhole sewing machine, the combination with stitch-forming mechanism including a needle operating from above the work, of buttonhole-cutting mechanism, means to cut the needle thread beneath the work at the end of the sewing operation, a

swinging pull-01f arm to engage the needle thread after it is cut and pull it back from the work, means to actuate said arm by the buttonhole-cutting mechanism, a normallyinoperative thread-gripping device carried by said arm, and means to render said device operative by the swinging movement of the pull-off arm.

6. In a sewing machine, the combination with stitch-forming mechanism including a needle operating from above the work, means for cutting the upper thread beneath the work at the end of the sewing operation, a swinging pull-off arm for pulling the cut end of upper thread back from the work, a normany-inoperative thread-gripping device carried by said arm, and means to render said device operative by the thread-pulling movement of said arm.

In testimony whereof, I have signed my name to this specification.

JOHN KIEWIoZ;

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