US3029759A

US3029759A - Cutting device

Info

Publication number: US3029759A
Application number: US861536A
Authority: US
Inventors: Victor J Sigoda
Original assignee: Individual
Current assignee: Individual
Priority date: 1959-12-23
Filing date: 1959-12-23
Publication date: 1962-04-17
Anticipated expiration: 1979-04-17

Description

April 1962 v. J. SIGODA 3,029,759

CUTTINGDEVICE Filed Dec. 23, 1959 2 Sheets-Sheet 1 IN VEN TOR. V/cro d. 5/500 ,4 rrop/YEy v. J. SIGODA CUT-TING DEVICE April 17, 1962 2 Sheets-Sheet 2 Filed Dec. 23, 1959 INVENTOR. Her-04 J. $16004 A TTO/P/YEY i u te EV C Victor J. Sigoda, 61 Old Pond Road, GreatNec-k, N.Y. Fae-a Dee. 23, 1959, seeNQ. 861,536

2 Claims. (Cl. 112-9127) This invention relates to a trimming attachment for use with zigzag sewing machines. More particularly, it concerns an attachment adapted to trim away the excess material from the bottom layer of fabric as an upper decorative" layer such as lace istopStitched thereto. Such work is known as applique in the trade and is used typically in the bodice and skirt portions of such feminine undergarments a'sslips and nightgowns.

In a general way, this attachment performs similarly to that disclosed in the Sigo'da U.S. Patent No. 2,432,545 of December 16, 1947. That device" also trims the excess'material from the edge of a bottom layer, leaving a small margin extending beyond the stitching. However, because the movable cutter is operated upwardly, and because of the bulk of the separator platform, that trimming attachment is limited in that it'cannot be used in the production of sharp, reverse points on such garments without making a cut in the fabric beyond the point. Since in the formation of such points, the line of stitching moves off in a reverse direction after the excc'ss is trimmed away, the out beyond the point is not subsequently covered by the stitching, and this leavesan unsightly cut in the garment.

In" the instant device, this limitation has been overcome by utilizing a movable cutter which operates downwardly against a novel stationary shear member which is part of a substitute needle-plate. The close adjacency of the shear edge to the needle hole and the rearrangement ofthe cutting action to a point just behind the needle makes possible the successful production-of sharp points in such garments;

The instant attachment structurally resembles that disclosed in Sigoda U.S. Patent No. 2,472,862 of June 14, 1949. It differs however in two significant respects. The earlier attachment was designed to provide a shear action inside the line of stitching so that no margin of goodswould be left outside the stitching after completion of the sewing. The instant attachment is arranged to leave a small margin of goods extending beyond the stitching on completion of'the' sewing: Furthermore, in the attachment of that patent, the cutters were arranged so that the desired shear action is effective immediately in front of the path of vertical reciprocation of the needle in the directionof the line of feed; In the present device, the arrangement is such that the shear action occurs rearwardly beyond the path of needle reciprocation.

Accordingly, it has been an object to provide a trimming attachment for use with zigzag sewing machines which is capable of producing sharp reverse points with out leaving any cut portion uncovered by the stitching.

With the above and such other objects as may appear in the following description, the invention as applied herein can be best understood by referring thereto in conjunction with the drawings, in which:

FIG. 1 is a view in perspective taken from the operators left showing the complete attachment as installed on the sewing machine, the presser foot having been indicated in broken line;

FIG. 2 is a detail view in perspective, the cover plate of the attachment having been removed, showing how the attachment fits into the throat-plate cutout of the sewing machine, and showing in particular the novel combined stationary shear member and needle-plate;

FIG. 3 is a detail view in perspective showing the feed-bar and the feed-dog mounted thereon; the support States Patent 3,Z59,759 P'a'tentedApr. 17, was

2 bracket for the movable cutter member, the operating connectio between thesupport bracket and the feeddog, and the operatingrelationship of the cutter members, the stationary shear member having been partly broken away;

FIG. 4 is an end sectional w'ew taken from the operators left showing the driving connection for the feedbar, and also showing the operating relationship of the cutter members;

FIG. 5 is a detail view, partly in section, taken on line 5-5 of FIG. 4, showing the drive connection between the feed-dog and the movable cutter bracket; and

FIG. 6 is an eiploded View, in perspective, showing the means for'rn'oiiiitingthe movable cutter on its support bracket.

Only so much of the zigzagmachine as is necessary to an understanding of the invention is indicated in the drawings; Referring now thereto, the cloth-plate 19' of the sewing machine is provided with a cut-out 11 for the usual throat-plate which is replaced when the attachmantis installed." The standard feed b'ar' 12 is provided with a modified form of feed-dog 14 which carries a stud drive shaft 15 (see FIG. 3) at its forward end and which extends laterally across the line of stitching. The feeddog is provided with the usual serrated teeth in a series of rows, the rightmost of which, as seen in FIG. 3, is useful in conjunction with the presser-foot in drawing away the trimmed off eii'cess from the bottom layer of fabric to remove it from the sewing area to avoid subsequent fouling.

A support plate 16 which carries the cutter elements is installed in'the cut-out 11 after theorigin'al throat-plate is removed. Plate 16 is provided with a pair of mounting holes 17 positioned to register with thethreaded holes in the machine bed,a'nd twosets of opposed, downwardly projecting ears 18, each set of which is designed to act as one bearing support for a movable cutter support bracket 19. Each ear of each set has a clearance hole in register to permit a screw such as that designated 20a in FIG. 3 to be mounted horizontally to provide a pivotal mounting for support bracket 19. Screws 20a are retained in place by round, slotted nuts 2%.

Plate 16 is also provided with an aperture 21 through which the feed-dog and the movable cutter operate, and a second set of holes through which screws may be passed to secure a combined stationary cutter andneedleplate member 22 on the upper surface of plate 16 (see FIG. 2).

Member 22 is L-shape in form and is pierced in one leg thereof with an elongated needle opening 24, immedi ately adjacent to one end of which, the edge 25 has been prepared" as a vertical shear face to mate with the movable cuttei'. Preferably this face is provided with a slight back-01f relief on the underside to assist in the shear action; Optionally, this edge may be faced with a hard, long wearing material such as tungsten carbide, to maintain' the shear edge in cutting condition for a long time before regrinding.

As best seen in FIG. 6, the movable cutter support bracket 19 is formed like a square letter C, with bearing hubs 26 formed on the extremities of the parallel arms thereof, and with a block 28 formed integrally with the bridge connecting the parallel arms. Bearing hubs 26 are provided for the pivotal mounting on screws 20a between the two sets of opposed ears 18 on plate 16 mentioned previously. Block 28 is part of the means for obtaining the vertical oscillation of bracket 19 which produces the cutting action and is also part of the means for retaining the movable cutter.

Block 28 is formed with a recess 29 in which the feeddog stud shaft 15 fits when bracket 19 is mounted in the machine cut-out 11, and a vertical slot 30 in which 3 cutter blade 31 is held by means of clamp block 32 and the screw 34 which passes through block 32 and into a horizontally disposed tapped bore in block 28. The tang of blade 31 is preferably serrated to provide better gripping action in slot 30 when screw 34 is tightened.

Movable cutter blade 31 is hook shape in form, and as may be noted in FIG. 6, the upper portion of this hook slopes to the rear. The face of this hook opposite the serrations is prepared as a shear face having a shear edge 35 disposed along the slope mentioned. Shear edge 35 cooperates with the shear edge 25 on the stationary cutter member 22. The tang of blade 31 may be adjusted vertically in slot 30 so that the cutting action which takes place as shear edge 35 moves downwardly against shear edge 25, is positioned along the line of stitching at a point just slightly rearwardly of the needle penetrations as the seam is formed. Because of the rearward slope of shear edge 35, it becomes apparent that the vertical adjustment of blade 31 in the clamp means on support bracket 19 will result in shifting the point of engagement of the shear edges either forwardly or rearwardly with respect to the needle penetrations, as desired. By keeping the point of engagement just rearward of the needle penetrations no cutting will occur beyond the point being sewn and this production defect is thereby eliminated. 1

When the cutters are assembled on support plate 16, it is desirable to provide resilient engagement between the shear edges. As seen in FIG. 3, leaf spring 36 is anchored under one of the screws 20a and turning screw 3-8 into the tapped hole provided in one of the arms of bracket 19 increased the pressure applied on the shear edges by the leaf spring.

When the assembled attachment is to be installed on the sewing machine, support plate 16, with the cutters mounted thereon, is placed into the throat-plate cut-out 11 with the stud shaft 15 on the feed-dog inserted into the recess 29 of the movable cutter support bracket 19. A cover or base plate 39 provided with a cut-out in which member 22 may lie flush with the surface thereof and through which the feed-dog 14 may also operate is installed on the cloth-plate of the machine by means of the standard countersunk head screws 40 which pass through holes 17 of plate 16 and into the existing threaded throat-plate mounting holes in the bed of the machine.

Since the sewing machine is provided with the usual four motion drive for the feed-bar 12, the feed-dog 14, and stud shaft accordingly, has two vertical movements, up and down, and these are transmitted from shaft 15 to support bracket 19 to operate the movable cutter as the sewing takes place.

In the installation of the attachment, nothing is done to interfere with the normal operation of the stitch-forming and feed members, and these functions are therefore carried out in the usual manner as the cutting action progresses. Since only the downward vertical movement of the feed-dog is efiective in producing the cutting engagement of the shear members, and since this coincides with the interval during which the feed is not effective to transport the work, the trimming of the surplus fabric from the bottom layer takes place while the work is at rest. This prevents bunch ing and wrinkling of the work or choking of the cutters which might occur if the cutting action were effective while the work was in motion.

In order to trim the bottom layer only, some means for separating the plies must be employed. In the mentioned patent, this function is performed by the platform portion of the stationary cutter designated 21a therein. The same function is incorporated into the presser-foot shoe in this instance, but since this is a matter well known in the art and which can be accomplished in a variety of ways, and since it is not part of the invention, it is not detailed either in the drawings or in this description.

What is claimed is:

1. In combination with a sewing machine having a needle reciprocating in a vertical path, a throat-plate cutout and a modified feed dog having a portion adapted to impart the vertical movements of said feed-dog; a support plate for a pair of cutting members adapted to be mounted in said throat-plate cut-out in replacement of the usual throat-plate; a movable cutter pivotally supported on said support plate and adapted to be rocked about its pivotal mounting by the said vertical movements imparted by the feed-dog when said support plate is mounted in the throat-plate cut-out; and a mating stationary cutter mounted on said support plate, said stationary cutter being provided with a transverse elongated needle opening and a shear edge formed adjacent one end of said needle opening, said movable cutter and said stationary cutter being so arranged and disposed with respect to each other and to the path of reciprocation of said needle that said cutters are effective to sever the work at a point beyond the said needle path rearwardly in the direction of the line of feed.

2. A combined needle-plate and stationary cutter member for use with a trimming attachment adapted to be installed on a sewing machine having a needle reciprocating in a vertical path and which is provided with a cut-out for a throat-plate and which has a modified feeddog adapted to impart the vertical movements thereof; said attachment comprising a support plate adapted to fit into said throat-plate cut-out in place of the usual throat-plate; a movable cutter pivotally mounted on said support plate adapted to be rocked about its pivotal mounting by the vertical movements imparted by the said feed-dog when the support plate is mounted in the throat-plate cut-out; said combined needle-plate and stationary cutter member being L-shape in form and havingan elongated needle hole transversely disposed in one leg thereof and a shear edge formed adjacent one end of said transverse needle hole, said stationary cutting member being adapted to be mounted on said support plate in mating engagement with said movable cutter and to be arranged so that the shear action of said cutters will be effective at a point beyond the said needle path rearwardly in the direction of the line of feed.

References Cited in the file of this patent UNITED STATES PATENTS