US2760453A

US2760453A - Anti-flagging devices for work-jogging attachments

Info

Publication number: US2760453A
Application number: US455701A
Authority: US
Inventors: John P Enos
Original assignee: Singer Co
Current assignee: Singer Co
Priority date: 1954-09-13
Filing date: 1954-09-13
Publication date: 1956-08-28
Anticipated expiration: 1973-08-28
Also published as: DE1770081U; GB772926A; CH333463A

Description

Aug. 28, 1956 J. P. ENOS 2,760,453

ANTI-FLAGGING DEVICES FOR WCRK-JOGGING ATTACHMENTS Filed Sept. 13, 1954 mmvron John R- Enos WITNESS ATTORNEY United States Patent ANTI-FLAGGING DEVICES F03 WGRK-EOGGING ATTA'CHIWENTS John P. Enos, Union, N. 3., assignor to The Singer Manufacturing Company, Elizabeth, N. 5., a corporation of New Jersey Application September 13, 1954, Serial No. 455,701

6 Claims. (Cl. 1l2-77) This invention. relates to work-jogging attachments for sewing machines and, more particularly, to cloth-holding devices for use with such Work-jogging devices by which the cloth in the immediate vicinity of the needle path is prevented from rising and falling with the needle or flagging, as this cloth movement is termed in the art.

It is an object of this invention to provide a clothholding device of the above character for a work-jogging attachment, which device is simple and economical to manufacture being preferably fabricated as a single sheet metal stamping.

It is a further object to provide an anti-flagging device which is inconspicuous in its application to a work jogging attachment for a sewing machine and which device insuch application will not lessen the range of adjustments of said attachment nor hamper the normal operation of said attachment.

The manipulation of the work fabrics at or very close to the path of the needle is of extrcmeimportance in sewing by machine for the reason that any deviation from the desired norm will be evidenced directly in the appearance of the stitching which results therefrom. This is particularly true in the production of patterns of stitches as with the use of work-jogging attachments on a sewing machine. Should the cloth flag or vibrate with the reciprocation of the needle, the unpredictable manipulations at the stitching point will have a detrimental effect upon the formation of a predetermined pattern of stitches. other possible objections thereto, such as the tendency for flagging to cause the skipping of stitches or thread breakage. Most of the cloth-holding devices of the prior art have an inherent defect in this regard in that the work.

engaging portions thereof travel in a path which is quite.

different from the path of needle reciprocation. While these prior devices reduce flagging of the work fabrics, they also act to shift the work slightly sidewise with respect to the needle path and, thus, introduce an undesirable work manipulation of their own.

It is still another object of this invention to provide an anti-flagging device having a work-engaging portion which is confined to move in a path which closely approximates that of the needle.

With the above and other objects and advantages in view as will hereinafter appear, this invention comprises the devices, combinations and arrangements of parts here-.

inafter described and illustrated in the accompanying drawings of a preferred embodiment thereof in which:

Fig. 1 is a right side elevation of a buttonhole attachment for a sewing machine having the anti-flagging device of my invention applied thereto;

Fig. 2 is a'left side elevation of the buttonhole attachment of Fig. 1;

This objection to flagging is quite apart from.

Fatented Aug. 28, 1956 "ice Fig. 3 is a front elevation of the buttonhole attachment.

of Figs. 1 and 2; and

Fig. 4 is an enlarged perspective view of the cloth.-

holding device of this invention together with fragments ofthe attachment frame and of the work-feeding foot.

Referring particularly to Figs. 1, 2 and 3 of the drawings, a buttonhole attachment for a sewingmachineis,

illustrated to which the anti-flagging device of my invention is applied. This buttonhole attachment, although it differs somewhat in appearance, is built substantiallyin accordance with the U. S. Schoonmaker. Patent No.

549,538, November 12, 1895, to which patent referencemay be had for a morecomplete description of the de-v tails of operation of the attachment. The general description of the attachment which will be given herewillcover in particular those aspects of the attachment which are salient from the standpoint of the present invention.

The attachment is constructed about a frame including right and left hand side walls 10 and 11, respectively,

as .viewed in Fig. 3, a bottom plate. 12, and a rearwardly extending tail portion 13 of side wall 10 which serves to support a linkage which controls the length of the buttonhole to be stitched. Between the forward extremities of the frame side walls It) and 11 is fixed a slotted block 41 by which the attachment maybe secured in the conventional manner to the pr-esser-bar 15 of a sewing machine.-

Slidably pivoted beneath the attachment frame bottom plate 12 is a feed plate 16 which is maintained in place by a keeper plate 17 and carries at :its forward extremity a hinged work-feedingfoot 18which is formed, as is usual in attachments of this type, with a substantially rectangular central opening 19 to expose the fabric section within which the buttonhole is to be stitched.

lournaled transversely between the frame side walls 10. and 11 are two

cam shafts

20 and 21. The forward shaft 20 carries a zigzag pattern cam 22 which serves through a follower lever 23 to. impart stitch-by-stitch jogging motion to the feed plate 16 and hence to the feeding foot 18. Shaft 21 carries a cross-over pattern cam 24 which actuates a followerlever 25 inv a well known manner to justing pin 29 to a vertically slotted extension 30 of the feed plate 16, and by this arrangement serves to shift the feed plate lengthwise back and forth along the length ofthe buttonhole to be stitched.

The

shafts

20 and 21 are both rotated in step-by-st ep, fashion by means of a forked needle bar actuated lever.

arm 31 which is freely journaled on shaft 20. and which is adapted to embrace a clamp 32 which serves to secure a needle 33 to the usual needle-bar34 of the sewing machine. The actuating lever arm 31 has pivoted thereto a pawl 35 which engages a ratchet 36 fast upon the shaft 20 so that intermittent step-by-step rotary motion is imparted to shaft 26 in response to reciprocation of the sewing machine needle-bar. A one-way clutch mechanism, shown generally at 37 in Fig. 1, is actuated by means of a lever arm 38 which is engaged and-os-f cillated by a lug 39 on the needle-bar actuated 1ever 31 to impart step-by-step rotary motion to theshaft 21.

The anti-flagging device of the present invention, as

best illustrated in Fig. 4, comprises. a lever of the third class which comprises asubstantially horizontalsection 40-- which at the rearward extremity is fulcrumed on a pivot screw 41 which is threaded into the frame side wall 11. At the opposite extremity, the horizontal lever section 40 is formed with a stripper foot 42 carried at the opposite extremity. The stripper foot is adapted to engage and apply downward pressure to the work fabric at a point within the rectangular opening of the work-feeding foot adjacent the path of the needle. Effort is applied to the horizontal lever section 40 between the fulcrum as .determined by the pivot screw 41 and the point of application of the downward pressure, i. e., the stripper foot 42 through means including a substantially vertically disposed section 43. As illustrated in Figs. 1, 2 and 3, the anti-flagging lever is arranged along the side wall 11 of the attachment frame With'the stripper foot 42 being disposed to extend beyond the frame so as to engage the fabrics within theopening 19 of the work-feeding foot. The pivot screw 41 of the lever is threaded into the side wall 11 of the attachment frame at the extremity of the attachment frame which is remote from the needle. The pivot screw 41 is arranged on the opposite side of the cam shaft 20 from the stripper foot 42.

As illustrated in Figs. 1 and 2, both the fulcrum, which is determined by the pivot screw 41, and the stripper foot 42 are disposed substantially along a common line which is perpendicular to the axis of reciprocation of the needle. The stripper foot will move in a slightly curved path about the pivot screw 41, however, its location on a line through the fulcrum and perpendicular to the needle path results in'a slightly curved stripper-foot path which closely approximates'the straight path of reciprocation of the needle. The paths of the stripper foot and the needle are made to correspond more closely by virtue of the type of lever which the anti-flagging device of this invention constitutes. Since the lever 40 is of the third class, the fulcrum may be disposed at the most remote point on the attachment frame, thus increasing the radius of stripper-foot movement to its maximum possible value and by so doing, making the slightly curved path of the stripper foot more nearly correspond to the straight path of reciprocation of the needle.

Movementof the anti-flagging lever is controlled by the vertically disposed section 43 of the lever which extends upwardly aud is formed with a laterally extending portion 44 so as to span the space above the frame side walls 14 and 11. Projecting forwardly from the laterally extending portion 44 are two

downturned lugs

45 and 46. Lug 45 is apertured, as at 47, to accommodate one extremity of a spring 48 which is anchored on the attachment frame and which serves to bias the anti-flagging lever downwardly to urge the stripper foot 42 into engagement with the work fabric. The lug 46 isdisposed at the free end of the laterally extending portion 44 and is disposed to overlie the forked needle-bar actuated lever 31 which is journaled on the cam shaft 20 and which serves to actuate the attachment as described above. The forked fabric in the direction of the reciprocations of the needle. Having thus described the nature of the invention jwhat I claim herein is: g g

1 A work-jogging attachment for a sewing 'machine comprising an attachment frame, a work-feeding member formed with an opening to expose the work to be stitched, means movably mounting said work-feeding member with respect to said attachment frame, mechanism carried-by said attachment frame and adapted to be actuated by said.

sewing machine for imparting work-jogging movements to said work-feeding'member, and an anti-flagging device comprising a lever, a stripper-foot formed at the extremity of said lever and arranged to extend within said open ing in the work-feeding member, said lever being fulcrumed at its opposite extremity to the attachment frame at a maximum distance from the aperture in said work feeding member determined by the lengh of the attachment frame, and means associated with said work-jogging mechanism for raising said stripper-foot, said means being disposed in operative engagement with said lever at a point thereon between said fulcrum and said stripper-foot.

2. A work-jogging attachment for a sewing machine having an endwise reciprocatory needle, comprising an attachment frame, a work-feeding member formed with an opening to expose the work for penetration by the needle, means slidably pivoting said work-feeding member to said attachment frame, a shaft journaled in said attachment frame, means carried by said shaft for jogging said workfeeding member, an anti-flagging device comprising a lever, said lever being fulcrumed at one extremity to said attachment frame at a maximum distance from the aperture in said work feeding member determined by the length of the attachment frame, a stripper-foot formed at the opposite extremity of said lever, said stripper-foot being disposed to extend into said opening in said Workfeeding member, and stripper-foot raising means associated with said shaft and disposed in operative engagement with said lever at a point between said fulcrum and said stripper-foot.

3. A sewing machine attachment comprising a frame, a shaft journaled in said frame, actuating means for imparting intermittent turning movement to said shaft, a work-feeding member mounted for movement with respect to said frame, said work-feeding member carried by said frame and extending beyond said frame at one side of said shaft, an anti-flagging lever, a stripper-foot carried by said lever and disposed to extend beyond said frame at the same side of said shaft as does said workfeeding member, means pivoting said lever to said frame at the opposite side of said shaft, and stripper-foot raising means pivotally mounted on said shaft.

4. A sewing machine attachment comprising a frame,

a shaft journaled transversely in said frame, a shaft actuating arm journaled on said shaft, operative connections between said actuating arm and said shaft for imparting intermittent turning, movements to said shaft, a workfeeding member slidably pivoted to said frame, said worka feeding member extending beyond said frame at one side 'posed to extend beyond said frame at one side thereof,

an actuating lever carried by said frame and arranged to operate said work-feeding member, an anti-flagging lever comprising three lever arms radiating from a common juncture, a work-engaging stripper-foot carried by a first of said lever arms and disposed adjacent to said work-feeding member, means pivoting a second of said lever arms to said frame adjacent to the juncture of said side wall and said bottom plate, and inter-engaging means carried on a third of said lever arms and on said attachment actuating lever for alternately raising and lowerin said stripper-foot. I

6. An anti-flagging device for a sewing machine workjogging attachment of the type having a movable attachment actuating member, said device comprising a leverof inverted T shape including a substantially horizontal section of said lever adapted at one extremity to be pivoted to said attachment, a downturned stripper-foot formed at the opposite extremity of said horizontal section, a substantially vertical section extending upwardly from a point between the extremities of said horizontal section, said vertical section being formed and adapted to engage said movable attachment actuating mechanism to impart rising and falling movements to said stripperfoot.

References Cited in the file of this patent UNITED STATES PATENTS Powell Dec. 16, 1890 Powell Jan. 26, 1892 Allenby Ian. 2, 1951 Connors July 3, 1951 Connors July 3, 1951 Johnson Oct. 30, 1951