US2063845A - Attachment for sewing machines - Google Patents

Description

Dec. 8, 1936. v J, D. KARLE ATTACHMENT FOR SEWING MACHINES Filed July 20, 1955 2 Sheets-Sheetl I6? ,33 10.1? l e4 2z Z117 14 M ,l l v g5` 1' l I T) I' 15 ,2a "I I l I] lf .l0 l1 12 :ji/,y )ccpl -u" 3 WIW d/ y Qq] 30 ,es 1 I 3E LVJ/m E1n/UW John D. Karla @mj/Z1 Dec. 8, 1936. J. D. KARLE ATTACHMENT FOR SEWING MACHINES Filed July 20, 1935 2 Sheets-Sheet 2 ma Willi/[0212i I gmc/Whom floh/n D. Karla Patented Dec. 8, 1936 UNITED STATES PATENT OFFICE ATTACHMENT FOR SEWING MACHINES Application July 20,

8 Claims.

This invention relates to sewing machines and more particularly to a presser-foot which is vibrated laterally of the line of seam and is adapted to be used for making ornamental seams.

The several features of the present invention will be clearly understood from the following description and accompanying drawings in which:-

Figure 1 is a front elevation of a zigzag-stitching attachment with my improved presser-foot attached, showing the needle in raised position and the position of the presser-foot at the completion of the right to left shifting movement.

Figure 2 is an elevation similar to Figure 1 showing the position of the presser-foot after the left to right shifting movement has been completed.

Figure 3 is a top plan view of the presserfoot.

Figure 4 is a bottom plan view of the presserfoot.

Figure 5 is a sectional view taken substantially along the line 5 5 of Figure 3.

Figure 6 is a side elevation of the stitch-linger, and Figure 7 is a top plan View of the finished work showing the seam produced by the attachment.

This invention is shown applied to a zigzagstitching attachment comprising a plate Ill xed to the presser-bar of the machine and formed with a cross-arm II which slidably carries a bar I2 having a depending portion I3. Pivotally secured by the pivot-pin I4 to the plate I0 is a lever I5 which is actuated by the needle-clamp I6 carried by the usual reciprocatory needle-bar I1 journaled in the head of the machine and carrying a needle I1.

The lever I5 carries a spring-pressed pawl I8 which actuates a ratchet-wheel I9 pivoted on the plate I0 and having rigidly attached to its rear face a cam 2@ the circumferentially spaced projections of which engage the inwardly extending projections 2I formed on the member 22 which is fulcrumed on the pivot-pin 23. Pivotally secured by the screw 24 to the upstanding post 25 of the cross-arm II is a bell-crank lever 26 one arm of which is bifurcated to receive the stud 21 carried by the swingable member 22 and the other arm formed with an arcuate slot 28. A link 29 operatively connects the slidable bar I2 to the bell-crank lever 26 and has one of its ends secured by the pivot-pin 3D to the bar I2 and its other end adjustably secured to the bell-crank lever by the thumb-screw 3I which extends through the arcuate slot 28. The above described 1935, Serial No. 32,349

mechanism for vibrating the presser-foot laterally of the line of seam formation is shown in my co-pending application Serial No. 758,381, led on December 20, 1934, to which reference may be had for a more detailed disclosure.

My improved presser-foot comprises a shank 32 which is adapted to be removably secured to the depending portion I3 of the slidable bar I2 by the screw 33. The shank 32 carries a rectangular shaped sole-portion 34 which is formed with a needle-opening 35 and a Work-engaging surface. The lower face of the sole-plate in rear of the needle-opening is cut away to provide a clearance groove 31 for the thread-loops and the sole-plate in front of the needle-opening 35 is formed with a half-round groove 3B which leads to the needle-opening to provide clearance for the initial stitches of the raised ornamental seam On the upward movement of the needle-bar I1 the needle-clamp I6 engages the free end of the lever I5 and moves the lever I5 and pawl I8 upwardly. During its upward movement the pawl I8 engages the ratchet-wheel I9 and advances it and the cam one-eighth of a revolution. The rotation of the cam 20 causes one of its circumferentially spaced projections to contact one of the inwardly extending projections 2| on the swinging member thereby causing the member to swing in a clockwise direction about its pivot 23. This swinging movement causes the pin 21 to swing the bell-crank lever in a counterclockwise direction about its pivot and this movement is imparted to the Slide-bar I2 by means of the link 29 thereby causing the presser-foot to move to the left to the position shown in Figure 1. The shifting of the presser-foot occurs while the usual feed-dog 44 is below the throatplate 45 and is completed just prior to the point in the cycle when the feed-dog contacts the work. After the feed-dog has advanced the work, the needle descends forming the stitch on the right side of the stitch-iinger, (Fig. 1), and on the upstroke of the needle the needle-clamp I6 again engages the free end of the lever I5 and the pawl again advances the ratchet-wheel and cam 20. The movement of the cam causes the swingable member 22 to shift in a counter-clockwise direction about its pivot and this movement is transmitted to the bar l2 by the bell-crank-lever 26 and the link 29, thereby shifting the presser-foot to the right to the position shown in Figure 2. The needle then descends on the left side of the stitch-finger forming a stitch and the needlethread extends from the rst needle-hole across the stitch-:linger to the second needle-hole. From the foregoing it will be observed that the zigzag attachment acts to shift the presser-foot laterally of the line of seam formation so that the needle descends rst on one side of the stitch-finger and then on the other. The tension on the thread is comparatively tight and as the stitches are formed over the stitch-iinger the stitches which have been laid over the finger cause the work to move with the presser-foot whereby the work is shifted laterally relative to the needle. The stitches 45 are formed near the top of the downwardly inclined thread-deecting portion 4| of the stitch-linger and when the stitch is being set the tension on the needle-thread causes the thread overlying the stitch-finger to slide down the downwardly inclined portion of the stitchnger so that the thread will be moved in rear of the needle-path to prevent its being pierced by the needle during the succeeding stitch-forming cycle.

Upon continued operation of the machine a series of stitches 46, (Fig. '7), are formed in the work 4l and over the stitch-inger and these stitches are fed forward by the feed-dog until they ride off of the tapered tongue of the stitchnger thereby forming a raised ornamental seam on the material being stitched.

It will be obvious that the stitch-finger may be removed by loosening the screw 40 and a stitchfinger of a different width placed on the presserfoot in order that seams of different widths may be produced. It is to be understood that the screw 3l may be adjusted in the slot 28 to vary the lateral throw of the presser-foot in accordance with the width of the stitch-iinger.

Having thus set forth the nature of the invention, what I claim herein is:-

1. A presser-foot for sewing machines comprising a shank, a sole-plate carried thereby, and a stitch-iinger carried by said sole-plate, said stitchfinger having an abruptly downwardly inclined thread-delecting portion.

2. A presser-foot for sewing machines comprising a shank, a sole-plate formed with a needle-opening and carried by said shank, and a stitch-linger secured to the upper face of said sole-plate, said stitch-finger having an abruptly downwardly inclined thread-deflecting portion extending through said needle-opening and a horizontally disposed rearwardly extending tongue.

3. A presser-foot for sewing machines comprising a shank, a sole-portion carried by said shank, said sole-portion being formed with a needle-opening, an unobstructed groove extending from the toe of said sole-portion to said needle-opening and a second groove extending from said needle-opening to the heel of said sole-portion, a stitch-finger carried by said sole-portion and extending into said needle-opening and through said second mentioned groove and means for adjustably and detachably securing said stitch-nger to said sole-portion.

4. A presser-foot for sewing machines comprising a shank, a sole-portion carried by said shank and formed with a needle-opening, a groove extending from the toe of said sole-portion to said needle-opening, and a clearance notch in rear of said needle-opening, and a stitch-finger adjustably secured to said sole-portion and having a downwardly inclined portion located in said needle-opening and a rearwardly extending tongue entering the clearance notch in rear of said needle-opening.

5. In combination with a sewing machine having a needle-bar adapted to be reciprocated in a xed path, a thread-carrying needle secured to said needle-bar, a presser-foot, a stitch-nger carried by said presser-foot and formed with a downwardly inclined and rearwardly extending thread-deilecting portion, and means actuated by said needle-bar for vibrating said presser-foot laterally relative to the needle, whereby the needle descends on rst one side and then the other side of said stitch-finger and the needle-thread is laid across said stitch-finger.

6. In combination with a reciprocatory needle and work-feeding mechanism, a laterally vibratory presser-foot, and a stitch-finger carried by said presser-foot and formed alongside the path of the needle with a downwardly inclined threaddeflecting portion.

7. In combination with a reciprocatory needle and work-feeding mechanism, a stitch-finger having an abruptly downwardly inclined portion located adjacent said needle and means for laterally vibrating said stitch-finger and needle relative to each other.

8. In combination with a reciprocatory needle and work-feeding mechanism, a stitch-finger having horizontally disposed portions located at different elevations and connected by an abruptly downwardly inclined portion located adjacent said needle and means for laterally vibrating said stitch-finger and needle relative to each other.

JOHN D. KARLE.

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