US1197234A - Thread-clamp for sewing-machines. - Google Patents

Description

F. A. READ.

THREAD CLAMP FOR SEWING MACHINES.

APPLICATION FILED NOV. 19. 1914.

Patented Sept. 5, 1916.

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WiTnesses.

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; ears aann'r Ff FRED A. READ, OF LYNN, MASSACHUSETTS, ASSIGNOR TO THE REECE BUTTON HOLE MACHINE COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OF MAINE.

THREAD-CLAMP FOR SEWING-MACHINES.

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Specification of Letters Patent.

Patented Sept. 5, 1916.

Application filed November 19, 1914. Serial No. 872,902.

To all whom it may concern: Be it known that I, FRED A. READ, a citi- -zen of the United States, residing at Lynn,

county of Essex, State of Massachusetts, have invented an Improvement in Thread- Clamps for Sewing-Machines, of which the following description, in connection with the accompanying drawing, is a spec1fication, like characters on the drawing representing like parts.

This invention has for its ob ect to provide a novel thread clamp for holding the end of the needle thread so that when the stitching operation is started the first stitch will be properly formed without danger that the end of the needle thread will be drawn through the fabric.

My invention is capable of use with sewing machines of different types, but I have herein illustrated it as it might be embodied in a so-called Reece buttonhole sewing machine. Examples of the Reece buttonhole sewing machine may be found in the following United States Letters Patent: No. 491,280, March 28, 1893; No. 655,637, August 7, 1900; No. 1,019,677, March 12, 1912.

Buttonhole sewing machines of this type embody work-holding means in which the work is clamped, and stitch-forming mechanism including upper thread mechanism and coinplemental under thread mechanism by which the buttonhole stitches are formed, said stitch-forming mechanism being carried by a suitable frame. When the machine is set in operation, the work-holding means and stitch-forming mechanism have a movement relative to each other to bring the stitch-forming mechanism and work-holding means into such relative position that the stitches will be properly formed on the buttonhole, this being referred to as the stitching position, and during the stitching operation said work-holding means and stitchforming mechanism have a further relative movement which is in the nature of a feeding movement to cause the stitches to be progressively made along the edges of the buttonhole. When the buttonhole has been completed, the stitch-forming mechanism is brought to rest, and said stitch-formmg mechanism and work-holding means have a further relative movement to bring the parts into their initial position.

Sewing machines of the above type are provided with buttonhole-cutting mechanism which operates to cut the buttonholeeither before or after the stitching operation. The cutting of the buttonhole is accomplished when the stitch-forming mechanism and work-holding means have a relative position different from that in which the stitching operation is performed, and which position will be referred to as the buttonhole-cutting posltion.

When the machine has been brought to rest at the end of the stitching operation, the stitch-forming mechanism and workholding means are in buttonhole-cutting position, and when the machine is first started, the work is clamped by the work-holding means, and if the machine is one which cuts the buttonhole before the stitching operation, the buttonhole will be cut, after which the stitch-forming mechanism and work-holding means have a relative movement to bring the parts into stitching position. The stitchforming mechanism is then set in operation and said stitch-forming mechanism and work-holding means have a relative feeding movement to provide for the formation of the edge stitches around the buttonhole, and when the stitching has been completed, the stitch-forming mechanism is brought to rest and said stitch-forming mechanism and work-holding means have a further relative movement to carry them into buttonhole-cutting position again, at which time the machine is brought to rest.

When the stitching operation is first started it is customary for the operator to hold the end of the upper thread which is controlled by a needle while the first stitch is being formed in order that at the first thrust of the needle a loop may be properly formed in the upper thread with which the under thread may be concatenated. If the end of the upper thread is not held either by the operator or some suitable means it frequently happens that the said end will be drawn through the cloth, thus destroying the loop with which the under thread is to be concatenated. If this occurs the first stitch will be spoiled. I have provided herein a novel device by which the end of the upper thread may be held during the formation of the first stitch, and in the selected embodiment of my invention this thread-holding device is associated with the work clamp, although this is not essential to the invention.

1 eye-pointed needle, and also includes comple- In order to give an understanding of my invention I have illustrated in the drawings a portion of a buttonhole sewing machine of the Reece typeto which my invention is applied. V

section on substantially the line-0a-a2, Fig. 3.

In thesewing machine herein illustrated, the st1tch-forming mechanism is sustained on a frame l which for convenience will be hereinafter referred to as the stitch frame.

This stitch-forming mechanism includes the usual upper thread mechanism in the form of a reciprocating needle bar 2 carrying an meiital'under thread mechanism which is not herein illustrated as it is not necessary to give an understanding of the invention.

The work-holding means is herein shown In the form of a clamp frame 3'on which the work is supported and work clamps 5 thatare supported by arms 4 that are pivotally' secured to the clamp frame 3 to permit the clamps to move toward and from the clamp frame thereby to clamp and unmove thev parts from b'uttonhole-cutting poclamp the'work. The stitch frame 1 withits stitchforming mechanism and the workholding means are constructed to be moved relative to each other, as above described, to

sition'to'stitching position and vice versa, andalso to provide the necessary feeding movement during thef stitching operation.

The means for giving the parts such rela- I tive movement are or may be all as illustrated in the above-mentioned patents and hence I have not deemed it necessary to furtlierillustrate or. describe it herein.

' i'arovided witha'needle thread cutter 6 which ,is mounted on a rock-shaft v7 journaled in Q'The sewing machine herein shown is also bearings 8 carried by the stitch frame,*saidrock-shaft being provided with an arm 9 1whi'ch is engaged by a finger 10 formed on the'igear 11 by 'which the. upper thread mechanism is rotated thereby tocause the 'cuttei dto sever the upper thread at the end of I the stitching operation on a button- Qhole. This thread cutter is similar to that *illustratedin *United States Patent-- No.

"forms nopart of thepresent invention, further description' thereof is not necessary.

E'Fig. l illu tratesin full lines the relative position of the stitclrforming mechanism .and'jwork-holding'meansat the time that the-sewing machinefis at rest, this position being referred to as the buttonhole-cutting I position. Then the machine is first started,

the work clamps 5 are brought into engagement with the work to hold it firmly while the buttonhole is being stitched, and if the machine is equipped with a buttonhole-cutting device that is designed to cut the buttonhole before the stitching operation, such cutting device will be actuated to perform its duties. The stitch frame and the workliolding means are then given a relative movement to .carry ,them from buttonholecutting into stitching position, and when they are in stitching position the stitchforming mechanismtis set in operation thereby to form the edge stitches of the buttonhole. The dotted line position in Fig. 1 shows the relative position of the stitchforming mechanism and the work-holding means when they are in stitching position. lVhen the stitch-forming mechanism is set in 7 operation the upper and under thread mechanism will operate on the work held by the work clamps to concatenate the edge stitches of the buttonhole, during which time the stitch frame and work-holding means or clamp frame are given a relative feeding movement. When the stitching has been completed around the buttonhole, the stitchforming mechanism is brought to rest and at this time the stitch-forming mechanism has a position relative to the clamp frame indicated approximately by the dotted line position Fig. 1. Thereafter, the stitch frame with its stitch-forming mechanism and the clamp frame or work-holding means have a further relative movement to bring the parts intobuttonhole-cutting position which isindicated by the full lines in Fig. 1. It is during this latter relative movement of the gstitch frame and the clamp frame or workholding means from stitching to buttonhole-cuttingposition that the thread cutter G is operated to sever the'needle thread beneath the clamps 5 which it will be under-' stood has been raised from the work after the buttonhole has been stitched.

My improved thread clamp is designed to seize and clamp the portion 13 of the upper thread 12 which extends between the needle and the work just after the completion of the stitching operation on any buttonhole and while the stitch frame and clamp frame or work-holding means are having their relative movement from stitching to buttonhole-cutting position. My thread clamp is also preferably designed to hold the needle thread after it has been severed and until the stitching operation on the next buttonhole begins,thus enabling the first stitch to be perfectly formed without any waste of thread such as results when the operator draws out the end of the needle thread to hold it. The thread clamp as herein shown comprises a body portion 14- adapted to be secured to one of the clamps 5, said bodyl portion having for this purpose a laterallya t! at leaf spring.

surface 20 a flaring throat into which the end 13 of the needle thread can enter. 21 is an adjusting screw which is screw-threaded into the body 14 and engages the plate 17 thereby to limit the movement of the clamping plate toward the body and to regulate the clamping pressure of the clamp on the thread. I

When the sewing machine is in operation stitching the buttonhole the needle for the upper thread is operating in the position shown in dotted lines Fig. 1 which is in the rear of the thread clamp. When the buttonhole stitching has been completed, the stitch frame and clamp frame have the relative movement above referred to to bring the parts into the full line position Fig. 1, and during this movement the portion '13 of the upper thread 12 which extends from the needle to the work will be carried into the flaring throat of the thread clamp formed by the portion 19 and curved edge 20 and will be carried into the space between the plate 17 and the body 1 1 and thereby clamped. The knife 6 is then operated to sever the thread below the clamp and the clamp retains its grip on the severed end of the thread while the machine is brought to rest and until the machine is set in operation again and the first stitches of the next buttonhole are formed. The grip of the clamp on the end of the needle thread is sufficient to cause the first stitch of the next buttonhole to be properly formed, and as the stitching on the next buttonhole continues the end of the thread will be pulled out from the clamp, as will be obvious. The adjusting screw 21 provides, as stated above, for regulating the clamping pressure on the end of the thread to correspond to the tension on the thread and the size of the thread, etc.

While I have illustrated herein a selected embodiment of my invention, I do not wish to be limited to the constructional details shown, as the form which the invention as sumes may be varied, and the manner in which it may be applied to sewing machines may also be varied, depending on the charactor of the machine.

I claim:

1. In a buttonhole sewing machine, the combination with stitch-forming mechanism, of work-holding means, said stitchforming mechanism and work-holding means having a movement relative to each other subsequent to the completion of the stitching operation on a buttonhole to bring the parts from stitching to buttonhole-cutting position, and a needle thread clamp carried by the won-holding means and located in such a position that the needle thread is drawn into said clamp during the relative movement of the parts from stitching to buttonhole-cutting position.

2. In a sewing machine, the combination with-a stitch frame carrying a reciprocating needle, of a clamp frame, said frames havmg a movement relative to each other in a direction at right angles to the movement of the needle after the needle has been brought to rest upon the completion of a predetermined stitching operation, a work clamp secured to the clamp frame, and a needle thread clamp carried by the work clamp in such a position that said relative movement of the frames will cause the portion of the needle thread extending from the needle to be carried into the thread clamp.

3. In a sewing machine, the combination with a stitch frame carrying a reciprocating needle, of a clamp frame, said frames having a movement relative to each other in a direction at right angles to the reciprocating movement of the needle after the needle has been brought to rest upon the completion of a predetermined stitching operation, a work clamp secured to the clamp frame for movement relative thereto, and a needle thread clamp carried by the work clamp and havin an open thread-receiving throat positioned so that such relative movement of the frames will cause the portion of the needle thread extending from the needle to the work to be carried into said throat.

1-. In a sewing machine, the combination with a clamp frame, of a work clamp movably supported thereby, a stitch frame carrying a reciprocating needle and having a movement relative to the clamp frame subsequent to the completion of a predetermined stitching operation, and a needle thread clamp secured to the work clamp and so situated that the needle thread is drawn into it by said movement of the stitch frame.

5. In a buttonhole sewing machine, the combination with stitch-forming mechanism and work-holding means having a movement relative to each other subsequent to the completion of the stitching operation on a buttonhole to carry the parts from stitching to buttonhole-cutting position, of a needle thread clamp carried by the work-holding means and presenting an open throat so situated that the needle thread is drawn into it by such relative movement.

6. In a sewing machine, the combination with a stitch frame carrying a reciprocating needle, of a clamp frame, said frames having a movement relative to each other after the completion of i a predetermined stitching operation, a thread clamp secured to the 'clamp frame and comprising a body member and a clamping plate resiliently held against the body member and presenting therewith an open throat so situated that the needle thread is drawn into it by such rela 'tive movement of the frames, and means to needle, of a clamp frame,'said frames having a movement relative to each other after the completion of a predetermined stitching operation, a thread clamp secured to the Witnesses:

the clamping pressure of the clamping plate is regulated.

In testimony whereof, I have signed my name to this specification, in the presence of .two subscribing Witnesses.

FRED A. READ.

J. WARREN NICHOLS, THOMAS J. GANTY.

A fiopies o f't his patent may be obtained for five cents each, by addressing the Commissioner of Patents,

7 Washington, D. C.

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