US1723898A - Sewing-machine take-up - Google Patents

Description

H. M. STEPHENSON SEWING MACHINE TAKE-UP Filed Ju1 y 15, 1927 Aug. 6, 1929.

Inventor: Hugh M. Stephenson, b2 %wh% His Attorney.

Patented Aug. 6, 1929.

UNITED STATES flfiitittitid PATENT OFFICE.

HUGH M. STEPHENSON, OF FORT \VAYNE, INDIANA, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

SEWING-MACHINE TAKE-UP.

AppIication filed July 13,

My invention relates to sewing machines and its object is to provide an improved and simplified oscillating lever take-up mechanism for varying the length of the thread taken up in proportion to the thickness of the material being sewn.

My invention will be more fully set forth in the following description referring to the accompanying drawing and the features of novelty thereof will be pointed out with particularity in the claims annexed to and forn'iing a part of this specification.

In the drawing, Fig. 1 is aside elevation )artly broken away of a sewing machine embodying my improved take-up; Fig; 2 is a section, of the arm of the machine on the line 22 of Fig. 3; F ig. 3 is an end elevation. of the arm of the machine with the cover plate partly broken away, and Fig. 4 is a perspective'view of the take-up arm and related parts.

Referring to the drawing, thesewing machine in connection with which I have illustrated my inventioncomprises a bed-plate 10 having an overhanging arm 11 extending therefrom for-supporting the needle bar 12, presser-foot 13 and take-up 14. A. needle 12 carried by the needle bar 12 and the presser-foot 13 carried by the presser-bar13 cooperate with a feed dog 15 and a suitable loop taker arranged below the bed-plate 10 to form stitches in theusual manner. During the operation of the machine thread is supplied to the needle 12 through the tensioning device 16, eyelet 14 of the take-up lever, upper thread guide 17 and lower thread guide 18 so that the downward movement of the take-up lever 14 forms an enlarged thread loop between the tensioning device 16, eyelet 14 and thread guide 17. The proper timing of the movement of the needle bar 12 and take-up 14 relative to the feed-dog 15 and the loop-taker is insured by a mechanical connection between these parts including the horizontal shaft 19 supported in the arm 11 which is also connected to a suitable driving means (not shown). The needle bar 12 is actuated by a crank 20 and connecting rod 21 which are supported. on the end of a cam 22 connected to the shaft 19. In accordance with my invention the take-up lever 14 is pivotally mounted at 23 on a block 24 which is slidably supported in a slot 25 formed in 1927. Serial No. 205,480.

the side wall of the arm 11. The take-up lever is oscillated about its pivotal support 23 by a roller 26 thereon which engages the cam 22 which is actuated by the horizontal shaft 19. It will be noted that the block 24 can be shifted in the slot 25 to vary the position of the pivotal support 23 relative to the cam 22 and to Vary correspondingly the distance that the take-up lever 14 moves below the upper thread guide 17 which controls the amount of thread taken up by the movement of the take-up lever and which advances the thread sufliciently to form the succeeding stitch. This variation in the length of the thread taken up by the move ment of the takeup lever 14 occurs because the size of the loop formed between the tensioninig device 16, take-up lever 14 and thread guide 17 depends upon the distance which the take-up lever 14 moves below the upper thread guide 17 and the tensioning device 16. The length of thread taken up and advanced by the movement of the takeup lever 14 is not affected by the variations of the distance between the eyelet 14 and the thread guide 17 when the take-up lever is in its uppermost position, because the slight amount of slack thread which is provided in the loop when thetake-up lever nearest the thread guide 17 is suliicicnt to prevent the take-up lever from exactly controlling the thread in this position.

It is well understood in the art that it is desirable to increase the amount of thread taken up and advanced by v the take-up mechanism as the thickness of the material being sewn increases. This is accomplished according to my invention by providing the presser-bar 1 3 with a cam 27 extending through a slot 28 in a link 29 which is connected to the pivotal take-up lever support 23 and is arranged to move the same so as to increase the length of thread taken up and advanced in proportion to the thickness of the material under the presser-foot. In order to prevent the cam 27 moving the link 29 vertically the latter is arranged to slidably engage a guide 30 formed on the side wall of the arm 11.. The cam 27 is provided with a straight portion 27 which CO1]- forms to the slot 28 but does not shift the position of the link 29 so that it will not interfere with the raising of the presser-bar .the bobbin case by the loop-taker.

of the stitch forming mechanism to form stitches in the usual manner. The feeding of material under the resser-toot 13 by the feed-dog l5 raises the presser-bar 13 against the presser-bar spring 15 and causes the cam 27 to shift the pivotal support 23 in theslot 25 by means of the link 29 an amount which is proportional to the thickness o'li the material between the resser-foot 13" and thevleectdog 15. This causes the take-up eye 14 to move downwardly below the thread guide 17 so as to take up and advance an amount of thread proportional to thethickness of the material so that the 30 requisite amount of thread is taken up to form the succeeding stitch and to form a thread loop large enough to be passed around The presser-foot 13 is raised or lowered by an increase or decrease in the thickness of the material which correspondingly increases or decreases the amount of thread taken up and advanced by the take-up lever 14, so that the machine operates effectively without breaking or snarling the thread as the thickness of the material under the pressenfoot varies during the sewing operation.

What I claim as new and desire to secure by Letters Patent of the United States, is 1. In a sewing machine, in combination, a presser-bar, means for taking up the thread in the machine during the stitch forming operation, and means for adjusting the length'of thread taken up and advanced by said take-up means, said adjusting means including a link, a slidably supported block attached thereto, and a cam on said presserbar for adjusting said block in response to variations in the thickness ol the malerial being sewn.

2. In a sewing machine take-up, in combination, means for guiding a thread, a lever including means for engaging the thread, a pivotal support for said lever, means for oscillating said lever about said pivotal support, and means for adjusting said pivotal support relative to the means for oscillating said lever to vary the range of oscillatory movement of said lever and the length of the thread taken up and advanced by the same in response to variations in the thickness ol? the material being sewn.

3. In a sewing machine, in combination, a presser-bar having a presser-foot thereon, means forguiding a thread, a take-up ineluding a lever having means for engaging the thread, a pivotal support for said lever, means for oscillating said lever about said pivotal support, and means actuated by said presser-bar for adjusting said pivotal support relative to the means for oscillating said lever to vary the range of oscillatory movement of said lever and the length of the thread taken up and advanced by the same in response to variations in the thickness of the material under said presser-foot.

l. In a sewing machine, in combination, a body member, a presser-bar supported on said body member and having a presser-foot thereon, means for guiding a thread, a takeup including a lever having means for engaging the thread, a pivotal support for said lever, said body member having a guideway slidably engaging 1 said pivotal support, means for oscillating said lever about said pivotal support, and means actuated by said presser-bar for adjusting the position of said pivotal support in said guideway relative to said body member to vary the range of the oscillatory movement of said lever and the length of the thread taken up and advanced thereby in response to variations in the thickness of the material under said presscrfoot.

In witness whereof, I have hereunto set my hand this 11th day of July, 1927.

HUGH M. STEPHENSON.

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