US2621618A - Combined sewing and trimming mechanism - Google Patents

Description

Dec. 16, 1952 D, TAYLOR 2,621,618

COMBINED SEWIMG AND TRIMMING MECHANISM Filed Sept. 4, 1948 5 Sheets-Sheet l a/= as. 5 A5 39 Zmventor 16, a T. D. TAYLOR 2,621,618

COMBINED SEWING AND TRIMMING MECHANISM" Filed Sept. 4, 1948 5 Sheets-Sheet 3 8 H 77 E/7/ll/lll Ill/ 1I I a, Z 2

3nventor Won/)4; 0. 72mm? (Ittomeg Patented Dec. 16, 1952 COMBINED SEWING AND TRIMMING MECHANISM Thomas D. Taylor, University City, Mo., assignor to Columbia Sewing Machine Corporation, a

corporation of New York Application September 4, 1948, Serial No. 47,930

13 Claims.

The invention herein disclosed relates to a combined sewing and edge trimming mechanism and comprehends an attachment'for a sewing machine by which the ordinary sewing machine is converted to a combined sewing and edge trimming mechanism.

The principal object of the invention is to provide an arrangement whereby the ordinary sewing machine is readily and easily converted into a combined sewing and trimming mechanism. Another object of the invention is to provide a trimming attachment for a sewing machine that may be afiixed to the sewing machine without the necessity of any machining operations on the sewing machine. A further object of the invention is to provide a pinking arrangement that utilizes cooperating relativelymovable V-shaped knives which pinking arrangement is readilythe work table in section, embodying my invention;

Fig. 2 which is a partial side elevation of the same;

Fig. 3 which is a plan of a pinking attachment, embodying the invention, taken on the irregular line 33 of Fig. 2;

Fig. 4 which is a sectional, side elevation of the same taken on the line l-:lof Fig. 3;

Fig. 5 which is a partial, sectional, side elevation of the same, taken on the line 5-5 of Fig. 3;

Fig. 6 which is also a partial, sectional, side elevation of the same, taken on the 1ine6--5 of Fig. 3;

Fig. 7 which is a sectional, end elevation of the same, taken on the line 1-1 of Fig. 2;

Fig. 8 which is a sectional, end eelvation of the same taken on the line 8-.-8 of Fig. 2;

Fig. 9 which is a sectional elevation taken on the line 8-9 of Fig. 4;

Fig. 10 which is an enlarged, partial, front, end elevation of the presser foot showing the position of the cloth in the sc-called plain stitching and pinking operation;

Fig. 11 which is a view similar to Fig. 10 showing the cloth in the so-calledtop-stitching and pinking operation; and

Fig. 12 which is a similar view of a modified foot and guide suitable for the plain stitching and pinking operation.

In general, the arrangement illustrated in the drawing includes the mechanism of the compart of the sewing machine includes the needlehead I, the work table 2 and the feed dog3. Slidably mounted in the needle-head i, thereiis the usual presser-foot bar 4 that is resiliently urged toward the work table 2, and the needle bar 5 that is reciprocated vertically in the usual manner. cooperates with a rotary hook I for the formation of stitches. The feed dogs 3 are actuated in the usual manner to advance the cloth being sewn, from right to left as seen in Fig. 1. All of the operating mechanism for such a sewing machine is old and well known in the art, and it has not, therefore, in the interest of providing aclear illustration of the invention, been disclosed in the drawing.

The particular trimming arrangement disclosed is for serrating or pinking the edge of material being sewn; it is of the kind that utilizes cooperating, relatively movable, male and female V-shaped pinking knives. The female knife 8 consists of a plate having a slot 9 cut through from one end edge thereof and terminating in converging, U-shaped cutting edges l0 and IL. The plate 8 is secured, by machine screws l2 and [3, to a presserfoot, designated generally by the numeral 14.

The presser foot [4 includes a shank portion l5 and a foot l6 that extends forwardly of the shank. The shank I5 is relatively wide and has alongitudinal groove I! that receives the end portion I8 of the presser-foot bar to which it is secured by a machine screw Illa. The side of the end portion ll; of the presser-foot bar that engagesthe base of the groove I1 is flattened to prevent relativeturning of the presserfoot with respect to the presser-footbar. An opening lS' is provided, through the shank, that corresponds v with, and has edges aligned with the edgesof the lower portion of the slot 9 through the female knife 8.

The foot I6 has a needle opening'zll therethrough through which the needle reciprocates to cooperate with the hook I. In addition, thefoot has a longitudinal slot 21 therethrough (Fig.- 2),. This slot has a side wall 22 that turns thejedg e of the cloth being sewn, andto be pinked, vertically and guides the edge intocutting relation with respect to the female knife, to the right of the femaleknife, as seen in' Figs. 2 and 4. To this end the wall 22 diverges from the engaging face of the foot and curves to the vertical. The

edge of the cloth entering the slot is thus, as it passes through the slot turned vertically, pre- The needle bar carries a needle 6 that sented to and moved past the cutting edges of the female knife.

A V-shaped, male knife 23 is reciprocated in a plane parallel to the work table, at right angles to the plane containing the axis of the presserfoot and needle bars 4 and 5, and cooperates with the female knife. The male knife and the actuating mechanism therefor are carried by a bracket 24 that is clamped to the presser-foot bar 4 above the presser foot. An end face 25 of the bracket 24 has a semi-cylindrical slot 23 therein and a clamping bracket 2'! has a like semi-cylindrical slot 23 therein. The slots 26 and 28 are such that when the presser-foot bar is received therein and the brackets secured together by machine screws 29 and 30, one on each side of the presser-foot bar, the bracket 24 is firmly and rigidly secured to the presser-foot bar.

The clamping bracket 2! has a bifurcated end portion 3| which extends downwardly and engages the shank l of the presser foot I4 on each side of the head of the machine screw l3a. The end portion 3| backs up the presser foot against the side thrust of the cutting action of the male knife entering the female knife. It is to be noted (Fig. 1) that the point of convergence of the cutting edges 0 and of the female knife is in line with the axis of the presser-foot bar 4.

The bracket 24 extends at right angles to the plane containing the axis of the presser-foot and needle bars 4 and 5, respectively. The bracket is bifurcated, forming spaced, bearing arms 32 and 33. A bell-crank lever 34 is pivoted between the arms 32 and 33 on a pivot screw 35 that extends through the arm 32 and that is threaded into the arm 33. One arm 35a. of the lever 34 extends downwardly and is pivotally secured to an end extension 36 of the male knife 23. The other arm 3! of the lever 34 has a gear sector 38 formed thereon. An integral guide extension 39 extends from the cutting end of the male knife and into the female knife. This guide extension, which engages the edges of the female knife, in the retracted or withdrawn position of the male knife, serves to maintain the male knife in proper relation with respect to the female knife.

The male knife is resiliently urged, by a plunger 45, in a direction at right angles to its line of movement or to press the point of convergence of its cutting edges toward the point of the convergence of the cutting edges of the female knife. The relation of the angle of the cutting edges of the female knife to the angle of the cutting edges of the male knife is such that when the male knife enters the female knife there is a shearing action, similar to that of shears, acting progressively towards the point of convergence. The plunger 40 extends vertically and is slidably mounted in a bushing 4| mounted in an opening 42 through the bracket 24. A head 43 on the plunger 40 engages the upper, flat surface of the male knife, and a spring 44 surrounding the plunger acts between the bracket and the head of the plunger. Thus, when the male knife is reciprocated, and the edge of the material being sewn is fed past the female knife and parallel to the surface thereof, a series of V-shaped notches are cut in the edge of the material.

The male knife is actuated through mechanism connected to the needle bar, preferably on alternate, penetrating strokes of the needle. For this purpose a split, pivot bracket 45, having a pivot 45 extending from the side thereof, is clamped on the needle bar by a clamping screw 41. One end of a lever 43 is pivotally secured on, the pivot 46 by a head screw 49. The other end of the lever 48 is pivotally secured to the end of a rocker arm 50 that is rotatably mounted on the end of a shaft 5| journaled in the arms 32 and 33 of the bracket 24 and extending through and beyond the arm 33. Intermediate the ends of the lever 48, there is pivotally secured thereto one end of a link 52. The other end of the link 52 is pivotally secured to a lever 53 that is rotatably mounted on the shaft 5|. The lever 53 has pivoted thereon a pawl 54 that cooperates with a ratchet wheel or crank 55 fixed on the shaft 5| on one side of the lever 53, between the lever and the rocker arm 53, and a ratchet wheel 56 rotatably mounted on the shaft 5| on the opposite side of the lever 53, and between the lever 53 and the arm 33 of the bracket 24.

The pawl 54 extends across the ratchets 55 and '53 and the lever 53 is .cut away at 5? to permit the pawl to engage both ratchets. A bifurcated extension 5? formed integral with the pawl has lateral extensions 53 that straddle the lever 53 and that are pivotally secured to the lever by a pivot 53. The pawl is resiliently urged into ratchet engaging position by a spring 3!] acting between a pin 6| extending from the end of the pawl and another pin 62 extending from the lever 53. The pawl may, however, for a purpose that will hereinafter appear, be held away from the ratchets, in a position in which it cannot engage the ratchets. This is effected through a manually operated throw-out lever 63 that is pivotally mounted between the arms of the bifurcated extension 57 of the pawl on a pivot 65. The throwout lever 53 includes a finger piece 65, through which it is actuated and a cam surface 35, pcsitioned to engage the edge of the lever In the position shown in Figs. 2, 5 and 6, the pawl is in ratchet-engaging position. If the finger piece 65 is moved to the left, the cam surface 63 engages the lever 53, raises the pawl, and maintains the pawl, out of ratchet engaging position.

Also fixed on the shaft 5| is a sector gear 3? that is positioned between the arms 32 and 33 of the bracket 25 and which meshes with the gear sector 38 formed on the arm 37 of the lever 33. Thus, when the lever 53 is actuated through the link 52 and the lever 43 and the pawl engages the ratchet '55, the shaft 5|, on the down stroke of the needle, is rotated counterclockwise as seen in Figs. 2, 4, 5 and 6. Through the gear sectors 5? and 38, the lever 35 is rotated clockwise and moves the male knife into cutting relation with the female knife. During the down stroke of the needle, the feed dogs are not acting on the material being sewn. Thus, the material is stationary while the cut is being effected. On the return stroke, the crank ratchet 55 is re turned through an abutment screw 63 (Fig. 6) that is threaded into the lever 53 and which is positioned to engage the edge of the crank ratchet which is in the form of a sector of a disk, at a point substantially diametrically opposite the point at which the pawl engages the disk.

The idler ratchet 53 is provided and arranged so that the pawl engages the crank ratchet 55 only on every other, or alternate penetrating strokes of the needle. To this end, the successive teeth of the idler ratchet are of different depth, alternate teeth being of the same depth. Thus, the teeth 59 are relatively shallow compared to the teeth E3. The depth of the teeth 53 is such that when the pawl engages a tooth 69, it is held positioned above the engaging edge of the crank ratchet 55. However, when the pawl engages or drops over a tooth ill. it is positioned to engage the crank ratchet 55. A stop or detent H pivotally mounted on a pivot l2 extending from the side of the arm 33 of the bracket 24 is positioned to engage the teeth 69 and iii of the idler ratchet 56 to prevent clockwise rotation thereof. The stop has an extension 13 thereon which extends under the lower edge of the arm 33. A spring 14, engaging the extension and the bottom of a hole in the lever, resiliently urges the stop into ratchet engaging position. It will be apparent that by increasing the number of teeth 69 between the teeth 10, the ratio of oscillations of the male knife with respect to the reciprocations of the needle may be varied.

The arrangement, above described, is suitable for effecting a plain stitch and pinking operation; a top stitch and pinking operation; and stitching without pinking. The passage of the cloth through the presser foot in the plain stitching operation is illustrated in Fig. 10. Two pieces of cloth 1'5 and 16 are laid one on top of the other with the end portions entered in the slot 22. As the cloth is moved through the machine by the feed dogs 3 the end edge portions of the two pieces of cloth are turned, by the wall 22, vertically and guided between the male and female knives of the pinker. In top stitching, one

piece of cloth I? is bent (Fig. ll) around the lower edge of the wall '22 and the under side of the foot. The other piece of cloth "is extends directly under the foot and into the slot 2i on top of the fold T9 in the piece i1. Again, the end portions of the two pieces of cloth are turned into a vertical position and guided to the pinker by the wall 22 of the slot 2i. It is to be noted that the feed dog 3 spans the slot 2i and thus acts upon both pieces of cloth in this latter arrangement.

In Fig. 12, there is illustrated a simplified arrangement for effecting the operation of plain stitching and pinking. With this arrangement a simple, unslotted p-resser foot 89 is used. A guide 81 is secured to the presser foot. The end edges of the two pieces of cloth being sewn, which end edges extend beyond the right of the presser foot, are turned vertically and entered between the guide 8! and the female knife 8. The guide 8| thus maintains the end edge portions vertical and guides them between the male and female knives.

When it is desired, to do plain sewing, i. e. without pinking, it is only necessary to actuate the throw-out lever 63 above described. This, as explained, raises the pawl 5- and holds it in raised position, so that it cannot engage the crank ratchet 55-. Thus, the actuating mechanism for reciprocating the male knife is rendered inoperative.

From the foregoing description of the sewing and pinking machine illustrated in the drawing, it will be seen, by those skilled in the art, that by this invention a simple effective arrangement is provided by means of which various forms of stitching, as done on the ordinary sewing machine, may be eifected and the edge of the material simultaneously pinked. It will also be apparent that by this invention there is provided a simple arrangement by which the ordinary sewing machine may be converted into a combined sewing and pinking machine.

It will be obvious that various'changes may be made by those skilled in the art in the details of the embodiment of the invention illustratedin the accompanying drawing and described above within the principle and scope of the invention as expressed in the appended claims.

I claim:

1. In a sewing machine having a slidably mounted needle-bar, feeding means for moving material to be sewn past the needle-bar, and means for effecting reciprocation of the needlebar and operation of the feeding means in timed relation with respect to the reciprocation 0f the needle-bar; the combination of edge-cutting mechanism comprising a bracket, cooperating relatively movable cutting knives, and operating means actuated from said needle-bar for effecting relative movement of the cutting knives in timed relation with respect to the reciprocation of said needle-bar and said feeding means and including mechanism for rendering the operating means ineffective upon certain reciprocations of the needle.

2. In a sewing machine having a needle-head, a needle-bar slidably mounted in the needle-head, a presser-foot bar adjacent the needle-bar, feeding means for moving material to be sewn past the needle-bar, and means for effecting reciprocation of the needle-bar and operation of the feeding means; the combination comprising a bracket secured to the presser-foot bar, a inovable cutting knife carried by the bracket, an operating element connected to the needle-bar and actuating means carried by the bracket and connecting said operating element and said movable cutting knife, and including mechanism operative to effect cutting movement of said movable knife only on alternate strokes of the needle.

3. In a sewing machine having a needle-head, a needle-bar slidably mounted in the needlehead, a presser-foot bar adjacent the needle-bar, feeding means for moving material to be sewn past the needle-bar, and means for effecting reciprocation of the needle-bar and operation of the feeding means; the combination comprising a bracket fixed with respect to the needle-head, a reciprocable cutting knife carried by the bracket, a lever connected to the needle-bar, and actuating means carried by the bracket and connecting said lever and said reciprocable cutting knife and including a pawl actuated by said lever, and a ratchet connected to said movable cutting knife and positioned to be engaged by said pawl.

4. In a sewing machine having a needle-head, a needle-bar slidably mounted in the needle-head, a presser-foot bar adjacent the needle-bar, feeding means for moving material to be sewn past the needle-bar, and means for effecting reciprocation of the needle-bar and operation of the feeding means; the combination comprising a bracket fixed with respect to the needle-head, a movable cutting knife carried by the bracket, a lever connected to the needle-bar, and actuating means'carried by the bracket and connecting said lever and said movable cutting knife and including a ratchet connected to said movable cutting knife, a pawl positioned to cooperate with said ratchet and connected to said lever, and manually operative means including a shiftable element having a finger piece thereon for removing the pawl from cooperative relation with said ratchet.'

5. In a sewing machine having a needle-head, a needle-bar slidably mounted in the needlehead, a presser-foot bar adjacent the needle-bar, feeding means for moving material to be sewn past the needle-bar, and means for effecting reciprocation of the needle-bar and operation ofthe feeding means; the Combination comprising a bracket fixed with respect to the needle-head, a movable cutting knife carried by the bracket, a lever connected to the needle-bar, and 'actuating means carried by the bracket and connecting said lever and said movable cutting knife and including a ratchet connected to said movable cutting knife, a pawl positioned to cooperate with said ratchet and connected to said lever, and means for withholding the pawl from cooperation with said ratchet only on alternate strokes of the needle 6. In a sewing machine having a needle-head, a needle-bar slidably mounted in the needle-head, a presser-foot bar adjacent the needle-bar, feeding means for moving material to be sewn past the needle-bar, and means for effecting reciprocation of the needle-bar and operation of the feeding means; the combination comprising a bracket fixed with respect to the needle-head, a movable cutting knife carried by the bracket, a lever connected to the needle-bar, and actuating means carried by the bracket and connecting said lever and said movable cutting knife and including a ratchet connected to said movable cutting knife, a pawl positioned to cooperate with said ratchet and connected to said lever, and means for withholding the pawl from cooperation with said ratchet on alternate strokes of the needle, including an idler ratchet having alternate teeth of different depth.

7. In a sewing machine having a needle head, a needle-bar slidably mounted in the needle-head, a presser-foot bar adjacent the needle bar, feeding means for moving the material to be sewn past the needle-bar, and means for effecting reciprocation of the needle-bar and operation of the feeding means; the combination comprising a presser-foot secured to the presser-foot bar, a female "cutting knife carried by the presser-foot bar and arranged in a plane parallel to the plane containing the axis of the needle and presserfoot bars, a bracket secured to the presser-foot bar, a movable cutting knife carried by the bracket and positioned to move into and out of said female knife, an element connected to the needle bar, and actuating mechanism connecting said element and said movable knife.

8. In a sewing machine having a needle-head, a needle-bar slidably mounted in the needlehead, a presser-foot bar adjacent the needle bar, feeding means for moving the material to be sewn past the needle-bar, and means for effecting reciprocation of the needle-bar and operation of the feeding means; the combination comprising a presser-foot secured to the presserfoot bar, a female cutting knife carried by the presser-foot bar and arranged in a plane parallel to the plane containing the axis of the needle and presser-foot bars, a bracket secured to the presser-foot bar, a movable cutting knife carried by the bracket and positioned to cooperate with said female knife, an element connected to the needle bar, and actuating mechanism connecting said element and said movable knife including a ratchet connected to said movable knife, a pawl positioned to cooperate with said ratchet, and'an idler ratchet having teeth of different depth for withholding the paul from cooperation with said ratchet on certain strokes of the needle.

9. An edge trimming attachment for a sewing machine of the kind described which attachment includes a bracket adapted to be secured to the presser-foot bar of a sewing machine, a movable knife carried by the bracket, a lever carried by the bracket and adapted to be secured to the 8 needle-bar of the sewing machine, and actuating mechanism carried by the bracket and connecting said lever and said knife and including means for eifecting cutting movement of the knife only on alternate oscillations of said lever.

10. An edge trimming attachment for a sewing machine of the kind described which attachment includes a bracket adapted to be secured to the presser-foot bar of a sewing machine, a movable reciprocable knife carried by the bracket, a lever carried by the bracket and adapted to be secured to the needle-bar of the sewing machine and actuating mechanism carried by the bracket and connecting said lever and said knife and including a ratchet connected to th knife and a pawl connected to the lever.

11. An edge trimming attachment for a sewing machine of the kind described which attachment includes a bracket adapted to be secured to the presser-foot bar of a sewing machine, a movable knife carried by the bracket, a lever carried by the bracket and adapted to be secured to the needle-bar of the sewing machine and actuating mechanism connecting said lever and said knife including a ratchet connected to said knife, a pawl positioned to cooperate with said ratchet, and means for withholding the paul from cooperation with said ratchet on certain strokes of the needle including an idler ratchet having alternate teeth of different depth.

12. An edge trimming attachment for a sewing machine of the kind described which attachment includes a bracket adapted to be secured to the presser-foot bar of a sewing machine, a movable knife carried by the bracket, a lever carried by the bracket and adapted to be secured to the needle-bar of the sewing machine and actuating mechanism connecting said lever and said knife including a ratchet connected to said knife, a pawl positioned to cooperate with said ratchet, means for withholding the paul from cooperation with said ratchet on certain strokes of the needle including an idler ratchet having alternate teeth of different depth, and manually operative means including a shiftable element having a finger piece thereon for rendering said pawl ineffective.

13. An edge-trimming attachment for a sewing machine of the kind described, which attachment includes a bracket adapted to be attached to the presser-foot bar and th following mechanism carried by the bracket, a stationary knife, a reciprocable knife positioned to cooperate with the stationary knife, a lever adapted to be connected to the needle-bar of a sewing machine, and actuating mechanism connecting said lever and said reciprocable knife including means for actuating the knife only on certain movements of the lever.

THOMAS D. TAYLOR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 498,617 Borton May 30, 1893 618,977 Baumann Feb. 7, 1899 1,560,163 Hughes Nov. 3, 1925 1,928,587 Card Sept. 26, 1933 1,946,558 Weiss Feb. 13, 1934 1,956,677 Gruman May 1, 1934 2,021,700 Pugach Nov. 19, 1935 2,105,184 Crewdson Jan. 11, 1938 2,510,929 Ketcham June 6, 1950

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