US2863408A

US2863408A - Contour sewing machines

Info

Publication number: US2863408A
Application number: US569638A
Authority: US
Inventors: George J Abel
Original assignee: Singer Co
Current assignee: Singer Co
Priority date: 1956-03-05
Filing date: 1956-03-05
Publication date: 1958-12-09
Anticipated expiration: 1975-12-09
Also published as: CH355344A; DE1185909B; GB806994A

Description

Dec. 9, 1958 G. J. ABEL CONTOUR sawme MACHINES 5 Sheets-Sheet 1 Filed March 5, 1956 P m G RP 0 LA 0 T w m E M M T mm m mmO HO Cs m MOTOR START MOTOR STOP . INVENTOR. George J. Abel Fig. 2.

WITNESS TTORNEY Dec. 9, 1958 G. J. ABEL 2,863,403

CONTOUR SEWING MACHINES Filed Mach 5, 1956 3 Sheets-Sheet 2 SOLB -{Z i i 26 53 INVENTOR.

George J Abel WITNESS BY 5 Sheets-Sheet 3 GIJ. ABEL CONTOUR SEWING MACHINES Dec. 9, 1958 Filed. March 5, 1956 A d m n m A m M V J. 0 W 2 I H S W. e W E .l m" R L R R g A M M a C C C f 0 e m G 2 W C M i M U 3 A m m L u A IYI IV LAc m m @E D1 D1 L O .o w m m g T1. H C R m m R my I 2 m M M w M A Ru" w. c c w 2 m m L m c M H \1L r 0 T.

5 52p m C.-

WITNESS States CONTOUR SEWING MACHINES Application March 5, 1956, SerialNo. 569,638 9 Claims. (Cl. 112-4) This invention relates to a machine for sewing automatically around a predetermined contour of compound curvature and more particularly to work-controlling means for such a machine which automatically simulates the normal hand guiding of material to the machine so that the Work is presented to the machine in such a way that the line of stitches is always tangent to the normal line of the machine feed at the needle.

in prior art devices of this kind the work is customarily confined to move relatively to the needle in but two component directions at right angles to each other and thus the work is not presented to the machine in the normal hand-guided fashion, which abnormal presentation adversely affects the formation of the stitches and the appearance of the finished seam.

it is a primary object of this invention to provide a sewing machine for sewing along predetermined contours of compound curvature in which the Work is automatically turned in any direction required to follow the contour and to make the line of stitches tangent to the normal direction of feed of the machine at the needle.

By contours of compound curvature is meant paths comprising joined line segments having any degree of curvature including reverse curvature.

It is a further object of this invention to provide a contour sewing machine having push-button initiated electric control of the sewing cycle so that the operator need only load and unload the machine, the cycle being automatically terminated at the completion of'the work.

With the above and other objects in View, as will hereinafter appear, the invention comprises the devices, combinations, and arrangements of parts hereinafter set forth and illustrated in the accompanying drawings of a preferrred embodiment of the invention, from which the several features of the invention and the advantages attained thereby will be readily understood by those skilled in the art.

In the drawings, Fig. l is a plan view of a machine embodying the invention.

Fig. 2 is an elevational view of the machine of Fig. 1.

Fig. 3 is an underside plan view of a IOQdEdWOIlC- holder used in the machine of Fig. 1.

Fig. 4 is a transverse section partly in elevation taken on line 4-4- of 2.

Fig. 5 is a diagram of the electric control system for the machine of Fig. 1.

Fig. 6 is a plan view of the cam track and the loaded work-holder with related parts indicated to facilitate following the path of the work-holder in making the seam.

Fig. 7 is a plan view of an unfolded work-blank and a service piece for use in the embodiment of Fig. 1.

Referring to Figs. 1 and 2, a sewing machine ll mounted on a table lll is driven by an electric power transmitter controlled by solenoids Sol. 1 and S01. 2. The solenoid-controlled transmitter 12 is the same as that shown and described in the U. S; patent application Serial No. 536,414; filed September 26; 1955, to which reference may be had for a better understanding of its operation. A circular guide plate 13 is set onthe table 11 and presents a work-supporting surface substantially flush with that of the bed 14 of the sewing machine 10. Cut into the guide plate 13 are continuous cam grooves 15, the purpose of which will be described presently.

A work-holder in, as seen best in FigS..3 and 4, is formed of two similar

flat pieces

17 and 18 of rigid material, each cut out to form a template having an outline shape conforming to the predetermined contour but somewhat smaller to allow the edges of a workblank 19 to protrude so that they may normally be. engaged by the feeding instrumentalities ofthe sewing machine ill. The work-blank 19,which comprises superposed plies of material to be stitched, is held between the two

parts

17 and 18 which are hinged at 20 to provide easy loading and unloading and which may be faced on the inner surface with felt 21 or similar friction material to increase their ability to hold the workblank 19 in accurate register. The lower one 18 of said parts carries

spaced rollers

22 and 23, one at each end. These rollers engage the cam grooves 15 and form a fixed wheelbase for the work-holder 16, and it is the cooperation betweenthe

rollers

22, 23 and the cam grooves 15 which establishes a predetermined desirable turning movement of the work-blank 16 as it is pulled along by the action of the sewing machine feed elements in gripping the work 19 at the edges to make the line of stitches follow the predetermined contour. For convenient reference the roller 22 will be designated as the upper roller and the roller 23 will be designated as the lower roller. The lower roller 23 is actually carried by a hub element 24 riveted to the part 18 and provided with a series of radial apertures 25 surrounding the roller 23.

Secured to the underside of the table 11, as seen best in Fig. 4, is a solenoid Sol. 3 having a vertically reciprocatable armature 26. Carried by the armature 26 is an auxiliary motor 27 with a vertically disposed shaft 28 terminating in a flange 29 carrying an eccentric pin 30 and concentric aperture 31. At a certain point in the cycle, as will be described presently, the solenoid Sol. 3 is energized and raises the motor 27 vertically from the dottedto the full-line position so that the eccentric pin 30 engages one of the apertures 25 in the hub 24 and the roller 23 engages the concentric aperture 31 in the flange 29. At the same time, the motor 27 is energized and adds its driving torque to the workholder which pivots about the axis of the shaft 28. In

this manner the work-piece is readily turned for sewing.

the other side of the contour without stopping the sewing machine.

The work-blank 19 may be a cut-out piece forming two similar halves 32-32 positioned back-to-back at a hinge portion 33 as shown in Fig. 7. This piece is folded about the hinge on dotted line 34 to form two overlapped plies in register and is placed in the work holder 16. Also placed in the holder is a service piece 35 of semicircular form cut from suitable material. This piece is placed at the small end of the work-blank 19 and is used to carry the sewing around this end without closing it so the machine can sew along both sides of the work-blank but not the ends. The service piece is later separated from the sewing work blank and may be used several times.

It will be noted from Fig. 1 that the cam grooves 15 cross at several points. At these points spring-biased swing gates 39 are provided to prevent the

rollers

22 and 23 from taking the wrong path. Where a change in function occurs in the cycle, there are limit switches LS1, LS2 and LS3, which are actuated by the rollers passing the predetermined points shown.

Referring to the diagram of Fig. 5 and to Fig. 2, there will now be described an electric control system J for establishing an automatic cycle of operations for the contour sewing machine of this invention. In Fig. a polyphase line P supplies power for the motor of the transmitter 12 and for the auxiliary motor 27 While a transformer Tr furnishes power to a control bus a, b.

The sewing machine is driven by transmitter 12 controlled by solenoids Sol. 1 and S01. 2. The transmitter motor is started by pushing the motor start button at push-button station 37 which, by reference to the diagram of Fig. 5, energizes a magnetic starter M1 to place the motor across the line in the usual manner. Once started, this motor is kept running as long as operations continue. The sewing machine 10 is started or stopped automatically by the solenoids Sol. 1 and S01. 2 which operate the transmitter clutch and brake respectively as will be described.

The loaded work-holder 16 is placed on the guide plate 13 with the

rollers

22 and 23 engaging the cam grooves as shown in the dotted lines of Fig. 1, and with the machine feed 36 engaging the protruding edge of the material 19. With the transmitter motor running, the operator pushes. the cycle start button at pushbutton station 38 which energizes relay CRS to close its normally-open contacts. Relay CR1 is energized and is locked in through the normally-closed contacts of a limit switch LS3. The brake solenoid Sol. 2 is deenergized by the opening of the normally-closed contacts of relay CR1, the clutch solenoid Sol. 1 is energized by the closing of the normally-open contacts of relay CR1, and the sewing machine 10 is started and continues to sew around the contour until the lower roller 23 comes to the center of the guide plate when the upper roller 22 hit the operator of the limit switch LS2 as shown in dotted lines in Fig. 1.

Closure of switch LS2 energizes a magnetic starter M2 through the normally-closed limit switch LS1 and the auxiliary motor 27 starts and runs. At the same time solenoid Sol. 3 is energized to raise the auxiliary motor 27 and cause the crank pin 30 to engage one of the apertures in the work-holder while the roller 23 engages the concentric aperture 31 in the flange 29. In this manner, the motor 27 drives the work-holder 16 through an arc of something over 180 degrees with the upper roller 22 following the circular arc groove 15 near the outer edge of the guide plate until it engages the operator of the limit switch LS1. This auxiliary feeding means is provided because the small radius of the contour in this region would give poor control of the work by the sewing machine feed alone.

Referring to Fig. 5, opening of the normally-closed contacts of LS1 deenergizes the starter M2 and releases the solenoid Sol. 3 thus retracting the crank-pin and deenergizing the motor 27 to stop the auxiliary feed. The sewing machine 10 continues to sew around the opposite side of the contour until the lower roller 23 engages the operator of the limit switch LS3 to open the normally-closed contacts thereof. This deenergizes the relay CR1 and the solenoid Sol. 1 thus releasing the clutch. At the same time closure of the normally-closed contacts of CR1 energizes the solenoid Sol. 2 to apply the brake and stop the sewing machine 10.

This completes the automatic cycle vof operation of the contour machine. The operator then removes the workholder, takes out the finished piece and installs the next piece.

The sewing machine may be controlled manually if desired by placing the selector switch at station 38 in the hand position which deenergizes relay CRH thus closing the normally-closed contacts of CRH, and the sewing machine will start and run as long as the machine start button is depressed. Emergency stop is effected by pressing the emergency stop button, which deenergizes the entire control bus at, b and thus removes excitation from both magnetic starters M1 and M2 to deenergize both motors.

Fig. 6 will assist in following the path of the workholder 16 as it is propelled along the cam track. U refers to the upper roller 22 and L refers to the lower roller 23. The letters A, B, C, etc. applied to the workblank refer to the associated portions of the contour being sewn. S indicates the starting point. The letters AU, AL, BU, BL, etc. applied to the cam grooves refer to the track followed by the upper and lower roller respectively in forming the seam in the A portion, B portion, etc. of the contour. The arrows indicate the direction of progress of the rollers in the cam track and the dotted lines indicate the starting position of the work-holder.

It will be seen from the above that I have provided a cycling sewing machine for stitching predetermined contours of compound curvature with provision for turning and guiding the material automatically so that the line of stitching is always tangent to the line of the machine feed at the needle shown by the arrow R in Fig. l, as would be the case with expert continuous hand-guiding.

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

l. A sewing machine for forming a seam automatically in a predetermined path of compound curvature, comprising stitch-forming and work-feeding instrumentalities, a horizontal work support fixed adjacent the stitchforming instrumentalities, two separate cam grooves formed in the surface of said work support, a workholder having clamp means for holding the work, and a pair of rollers mounted in fixed spaced relation on said work-holder and each in engagement with a respective one of the cam grooves in the work support to guide the work-holder as it is propelled over the work support by the action of the work-feeding instrumentalities onthe work.

2. A machine for sewing automatically around a predetermined contour, comprising a sewing machine having a work-supporting surface, stitch-forming and workfeeding instrumentalities, a stationary guide-plate mounted flush with the Work-supporting surface to provide an enlarged flat work-supporting area, separate cam grooves formed in said guide-plate, a portable work-holding frame having upper and lower elements between which the work is clamped and having a marginal contour in the shape of the path to be followed by the stitching instrumentalities, and spaced follower rollers mounted on the lower element for cooperative engagement with the respective cam grooves of the guide plate for controlling the direction of movement of the work-holding frame relative to the stitch-forming instrumentalities as it is propelled over the guide-plate by the work-feeding instrumentalities acting on the work clamped in the frame.

3. A machine for sewing automatically around a predetermined contour, comprising a sewing machine having a work-supporting surface, stitch-forming and work-feeding instrumentalities, a stationary guide-plate forming an extension of the work-supporting surface, separate cam grooves formed in said guide-plate, a portable work-holder having similar upper and lower elements between which the work is clamped and having a marginal contour in the shape of the path to be followed by the stitching instrumentalities, and a pair of spaced follower rollers carried by the lower work-holder element for cooperative engagement with the respective cam grooves of the guide r plate which imposes on the work-holder angular movement relative to the stitch-forming instrumentalities as it is propelled over the guide-plate by the work-feeding instrumentalities acting on the work clamped in the holder.

4. In a sewing machine for forming a seam automatically along a predetermined contour, stitch-forming elements, work feeding elements, means for guiding the work relative to said stitch-forming elements comprising a work support, a pair of continuous cam track formed in the work support, a work-holder having an outer margin in the shape of the contour to be sewn, clamp means for holding the work in the holder with its peripheral edges presented to the stitch-forming and work-feeding elements, and a pair'of spaced guide means secured to the work-holder and engaged respectively with said cam tracks for imparting turning movements to the work-holder as it is propelled over the work support by the work-feeding elements acting on the work clamped in the holder.

5. Apparatus for presenting work automatically to the feeding and stitch-forming instrumentalities of a sewing machine to form stitches in the work along a predetermined path of compound curvature comprising a work support, a pair of continuous cam tracks formed in the work support, a work-holder slidable on the work support and having an outer margin in the shape of the path of compound curvature, clamp means for holding the work in the holder with its peripheral edges protruding from the holder to be engaged by the stitch-forming and feeding instrumentalities, and a pair of rollers secured to the work-holder in fixed spaced relation and engaged each with a respective one of said cam tracks to guide the work-holder as it is propelled over the work support by the feeding instrumentalities acting on the work clamped in the work-holder.

6. A sewing machine for forming a seam automatically in a predetermined path, comprising vertically disposed stitch-forming and work-feeding instrumentalities, a horizontal work support adjacent the stitch-forming instrumeutalities, separate cam grooves formed in the surface of said work support, a work-holder having clamp means for holding the work, and a pair of spaced rollers fixed to said work-holder and each in engagement with a respective one of the cam grooves in the work support to guide the work holder as it is propelled over the work support by the action of the Work-feeding instrumentalities on the work, and auxiliary work-feeding means rendered effective responsive to the progress of the rollers along the cam grooves to drive said work-holder over predetermined portions of the seam path.

7. Apparatus according to claim 6 including means for 5 driving the sewing machine comprising a solenoid-operated electric power transmitter.

8. Apparatus according to claim 7 including control means comprising relays and limit switches for operating the sewing machine and the auxiliary work-feeding means in a predetermined cycle manually initiated and automatically terminated.

9. In a sewing machine for forming a seam automatically along a predetermined contour, stitch-forming elements, work-feeding elements, means for presenting the work to said work-feeding elements and for guiding the work relative tosaid stitch-forming elements comprising a Work support, a pair of continuous carn tracks formed in the work support, a work-holder having an outer margin in the shape of the contour to be sewn, clamp means for holding the work in the holder with its peripheral edges presented to the stitch-forming and work-feeding elements, and a pair of spaced guide elements secured to the work-holder and engaged each with a respective one of said earn tracks for imparting suitable turning movements to the work-holder so that the seam follows the predetermined contour as the work is progressively advanced in one direction under the control of the work: feeding elements.

Kramer et al Sept. 9, 1952 Freeland et al Aug. 6, 1957