US2880683A

US2880683A - Contour sewing machines

Info

Publication number: US2880683A
Application number: US565569A
Authority: US
Inventors: George J Abel
Original assignee: Singer Co
Current assignee: Singer Co
Priority date: 1956-02-15
Filing date: 1956-02-15
Publication date: 1959-04-07
Anticipated expiration: 1976-04-07
Also published as: DE1165979B; GB812220A

Description

G. J. ABEL CONTOUR SEWING MACHINES April 7, 1959 6 Sheets-Sheet 1 Filed Feb. 15, 1956 lllll 2% a d S d S M. m 2

P O u 7. GP w LM m H 1 mm m an :w. .7 r mwO m6 mwO a E ,M I a 3 k 2 I- I0 George J. Abel 9 ATTORNEY WITNESS April 7, 1959 G. J. ABEL CONTOUR SEWING MACHINES Filed Feb. 15, 1956 6 Sheets-Sheet 2 Fig. 3.

INVENTOR. George J. Abel ATTORNEY WITNESS I G. J. ABEL CONTOUR SEWING MACHINES April 7 1959 6 Sheets -Sheet 3 Filed Feb. 15, 1956 A .A 7/ m fl w V m W 9 8% m \a m w Y m M M m VJ T We OW m w G V. B B

WITNESS G. J. ABEL CONTOUR SEWING MACHINES April 7, 1959 6 Sheets-Sheet 4 Filed Feb. 15, 1956 L L O 0 2 S 1 2 3 4 R H l l R R m w m m u m c c c M M LVI L .ll .Ilm mm 0 A 0 m r 3 m A fl .n n A T L E 00 DI m F m m S I l S C C P M H o o m 9 P R 4 G H R M T 1| H a C m z m m m 4 T S M m" d RHHM m c RH" c T S c s n X H m M m N H m H, m WL C .m

INVENTOR. Gearge J; Abel 84W v ATTORNEY WITNESS G. J. ABEL CONTOUR SEWING MACHINES April 7, 1959 6' Sheets-Sheet 5 Filed Feb. 15, 1956 INVENTOR. George J. Abel WITNESS TTORNEY I April 1959 G.VJ. ABEL 2,880,683

CONTOUR sswmc MACHINES I Filed Feb. 15, 1956 6 Sheets-Sheet 6 CYCLE EMERG.

McSTART MILSTOP INDEX SEL. START Hand Auto 7 MOTOR START MOTOR STOP 7 Fig. IO.

INVENTOR.

George J. Abel WITNESS wab a 61%,

TORNE Y United States. Patent CONTOUR SEWING MACHINES George J. Abel, Watchung, N.J., assignor to The Singer Manufacturing Company, Elizabeth, N.J., a corporation of New Jersey Application February 15, 1956, Serial No. 565,569

2 Claims. (Cl. 112-2) This invention relates to contour sewing machines and more particularly to apparatus and control means for presenting material automatically to the stitching instrumentalities of a conventional sewing machine to effect a seam along a predetermined contour path of compound curvature.

Prior art devices in this field have been deficient generally in that the material to be sewn has been confined to move inbut two component linear directions with respect to the stitching instrumentalities. This prior presentation of the material does not always accord with the normal direction of machine feed and adversely affects the stitch formation and the appearance of the finished seam particularly where seam paths of compound curvature are involved.

It is a primary object of this invention to provide apparatus and control means therefor for sewing automatically along a predetermined path of compound curvature using a conventional sewing machine.-

It is a further object of this invention to provide material control means for a sewing machine including feeding means whereby the material is automatically guided to and fed past the stitching instrumentalities in the normal direction of machine feed in making a seam following a predetermined path of compound curvature.

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 preferred 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. 1 is a plan view of apparatus embodying the invention.

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

Fig. 3 is a partial view taken on line 33 of Fig. 2.

Fig. 4 is a detail plan view of the cam drive mechanism of Fig. 3.

Fig. 5 is a longitudinal sectional view taken substantially on line 55 of Fig. 4.

Fig. 6 is a diagram of the electric control system for the machine of Fig. 1.

Fig. 7 is a detail bottom plan view of a modified cam drive mechanism.

Fig. 8 is a longitudinal sectional view taken substantially on line 88 of Fig. 7.

Fig. 9 is similar to Fig. 2 but shows a modification in which normal driving of the cam is derived from the intermittent sewing machine feed except during the 180 degree non-sewing reversal of thework.

Fig. 10 is an end elevational view of the embodiment of Fig. 9.

A sewing machine 10 is mounted on a table 11 which has been modified by including a special cut-out section 12 forming a work support. The sewing machine 10 is driven by an electric power transmitter 13 controlled 2. by solenoids Sol. 1 and S01. 2. This solenoid-controlled transmitter is described at some length in US. application Serial No. 536,414, filed September 26, 1955, to which reference may be had for a more complete understand= ing of the operation of this device.

Secured beneath the table and. extending in spaced par= allel relation to the top work support 12 is a horizontal shelf 14 for slidably supporting an annular cam 15 as will be explained. An electric cam-drive motor 16 located beneath the cam-supporting shelf 14 drives a vertical shaft 17 through a speed reducer 18 and bevel gears 19. The shaft extends upward through the shelf and terminates in a toothed drive wheel or pinion 20 which engages the outer toothed periphery of the cam 15. The vertical shaft 17, it will be noted, is so located relatively to the sewing machine that the needle 21 is in line vertically with the contact line between the drive wheel and the cam periphery. In this manner it will be seen from what follows that any turning of the work in order to follow the predetermined contour path will always be substantially about the needle axis. The cam 15 is continuous and annular, and has an outline shape the same as the contour path of the seam to be made as will be seen best in Fig. 3. Spaced idler rollers 2222 bear on the inner periphery of the annular cam 15 and they are positioned relatively to the drive wheel 20 to keep the tangent to the periphery of the cam at the drive wheel in the direction of normal feed of the sewing machine 10 as the cam 15 slides over the surface of the support 14 and is driven by the drive wheel 20.

Reference to the details of Figs. 4 and 5 shows how pressure is applied to the cam 15 to keep it in proper driving contact with the drive wheel 20. The rollers 22-22 are spaced equally on opposite sides of a centerline XX which passes through the axis of the drive wheel 20 and is at right angles to the normal direction of sewing machine feed. Pivot pins 23-23 for the rollers 22-22 are secured to a T-block 24 which has a stern portion 25 arranged to slide within ways to confine its motion along the centerline. The ways comprise side members 26-26 and a top member 27 secured to a horizontal platform 28 which also forms a support for the bearings 2929 in which the drive-wheel shaft 17 is journaled. A compression spring 30 seated within a central recess 31 in the stem portion 25 reacts against a closure member 32 to urge the T-block 24 to the right as shown, and with it, the rollers 22-22 urge the annular cam 15 into driving contact with the drive wheel 20 as shown. A pull rod 33 which passes axially through the center of the spring 30 and is threaded into the T-block 24 is employed to pull the rollers 22-22 out of engagement with the cam 15 so that it may be manually postioned if necessary. This arrangement provides an equal application of pressure on the cam 15 at two points symmetrically spaced with relation to the drive wheel 20 and in a direction at right angles to the normal direction of sewing machine feed, with the result that the cam tontour is urged into a tangent position relatively to the normal line of feed.

As seen best in Figs. 1 and 2 a work-holder comprising two superposed hinged

templates

34 and 35 is carried by a vertical post 36 which extends downward through the aperture 37 of the cut-out section 12 and is adjustably secured in a socket member 38 fixed to a cross-bar 39 which in turn is secured to the cam 1 5. The

superposed templates

34 and 35 have a peripheral shape conforming to and in register with the outer periphery of the cam 15 but are somewhat smaller to allow the work blank 40 to protrude at the edges to be engaged by the needle 21 of the sewing machine 10. I

it -will be seen from the abovethat the feeding of the cam 15 by the drive wheel 20 and the angular guiding 3 thereof by the rollers 22-22 imparts to the

work holder

34, 35 and the work 40 held therein a feeding and a turning action which closely simulates hand guiding action and results in automatic movement of the material past the needle always in the direction of the normal feed of the sewing machine as indicated by the arrow R of Fig. 1 and Fig. 3.

Referring to the diagram of Fig. 6 and to Fig. 2, there will now be described an electric control system for establishing an automatic cycle of operations for the contour sewing machine of this invention. In Fig. 6 a polyphase line L supplies power for the cam drive motor 16 and the motor of the transmitter 13 while a transformer Tr furnishes power to the control bus, a, b. With the work blank 40 clamped in the

work holder

34, 35 positioned as shown in Fig. 1, the operator pushes the motor start button located at a push-button station 41. This energizes a magnetic starter M-2 to start the motor of the electric power transmitter 13 in the customary manner. Once started, this motor continues to run as long as operations continue.

To initiate the sewing cycle, the operator pushes the cycle start button located at push-button station 42 to energize relay CRS which is locked in through the nor mally-closed contacts of relays CR2 and CRR. Opening of normally-closed contacts of CRS deenergizes solenoid Sol. 2 to release the transmitter brake and closure of normally-open contacts of CRS energizes solenoid Sol. 1 to engage the transmitter clutch thus starting the sewing machine. Relay CR1 is energized and is locked in through normally-closed contacts of a timer T-1. The timer T-l is also energized, as is the magnetic starter M1 which thus starts and runs the cam drive motor 16 to feed the work 40 to the stitching instrumentalities of the sewing machine 10 in a predetermined path set by the peripheral shape of the annular cam 15. Some of the successive positions of the cam 15 during this feeding of the work are seen in the dotted line views A, B, C and D of Fig. 3.

At the end of the time for which the timer T-l is set, at which time the work holder has reached approximately the position indicated in the dotted lines in Fig. 1, closure of normally-open contacts of timer T-l energizes relay CR2 through normally-closed contacts of relay CRR. Opening of normally-closed contacts of timer T-1 deenergizes relay CR1 and restores timer T-l to starting condition. Closure of normally-pen contacts of CR2 energizes relay CR3 through normally-closed contacts of timer T-2. Opening of normally-closed contacts of CR2 deenergizes relay CRS, releases the clutch solenoid Sol. 1 and energizes the brake solenoid Sol. 2 to stop the sewing machine. The magnetic starter M-1 is also deenergized to stop the cam drive motor.

Closure of normally-open contacts of CR2 also energizes the timer T-2 which starts timing to provide a delay to enable the operator to cut the thread before tfurther feeding of the material 40 by the cam drive motor 16.

At the end of the period for which the timer T-2 is set, closure of normally-open contacts of T-Z energizes relay CR4 and timer T-3. Opening of normally-closed contacts of T-2 deenergizes CR3, and timer T-2 is restored to starting condition. Closure of normally-open contacts of CR4 energizes starter M-1 and the cam drive motor 16 starts and runs driving the

work holder

34, 35 to its starting position, which period is timed out by the timer T3. Successive positions assumed by the cam 15 during this feeding period are indicated by the dot-dash line views E, F and A of Fig. 3. At the end of the period for which T-3 is set, normallyclosed contacts of T-3 open and deenergize relay CR4 to reset timer T-3. Opening of normally-open contacts of CR4 deenergizes the starter M-1 and stops the cam drive motor 16. This completes the normal cycle of operations of the contour machine. The operator opens the hinged

work holder

34, 35, takes out the finished work piece 40, inserts a new blank and closes the holder in readiness for starting the next cycle.

With the selector switch at station 42 set to hand position relay CRH is energized. Closure of normallyopen contacts of CRH permits starting of the sewing machine by pushing the machine start button but prevents all other automatic operations because normallyclosed contacts of CRH open to prevent operation of timer T-l, relay CR1 and starter M-1.

Normally-open contacts of CRH close to permit energizing starter M-1 by holding down the index start button at station 42 for manual control of the cam drive motor 16.

An emergency stop button is provided at station 42 and operates as follows: closure of emergency stop button energizes relay CRR whose normally-closed contacts open to deenergize relay CRS which release clutch solenoid Sol. 1 and energizes brake solenoid Sol. 2 to apply the brake and stop the sewing machine 10. Opening of normally-open contacts of CRS deenergizes magnetic starter M-1 and stops the cam drive motor 16 unless the cycle is on T3, in which case it will be stopped soon anyhow. Opening of normally-closed contacts of CRR deenergizes relay CR1, resets timer T1, and deenergizes relay CR2. Opening of normally-open contacts of CR2 deenergizes relay CR3 and stops timer T-2.

A modified mechanism for driving the annular cam 15 is shown in Figs. 7 and 8. In this case the rollers 41-41 are spaced equally on each side of a center-line Y-Y which passes through the axis of the drive wheel 42 and is at right angles to the normal direction of sewing machine feed. However, the rollers 41-41 are each mounted on separate slides 43-43 which confine their movement to an individual linear back-and-forth motion parallel to the center-line Y-Y. The slides 43-43 are confined to move within a block 44 fixed to a base-plate 45 which serves as a support for a bearing member 46 in which is journaled the shaft 47 for the drive-wheel 42. Link elements 48-48 connect the slides with a common floating link 49 to the center of which is pivotally secured one end of a lever 50 pivoted at 51 and having a handle 52 at the opposite end. Springs 53-53 secured at one end to pivot pins 54-54 are each adjustably anchored at their other end in blocks 55-55 secured to the base-plate 45 and provide individually adjustable bias for the rollers 41-41 to urge them against the cam 15 and thus to maintain the cam 15 and drive wheel 42 in proper driving contact. By manipulation of the handle 52 the rollers 41-41 may be retracted and the cam drive disengaged. By means of this construction there is individual springing for each roller with a difierential lift action which enables the rollers to follow the cam contour easier and to maintain better control of the cam position in accordance with the desired result of simulating precision hand guiding action over stitching paths of compound curvature.

In the foregoing embodiments the work is fed past the needle at a constant rate by a motor-driven cam and this is the preferred form. It may, however, be desirable at times to employ an intermittent feed for the work, synchronized with the needle reciprocations, and a modification to accomplish this is illustrated in Figs. 9 and 10. In this case an eccentric cam 56 mounted on the armshaft 57 of the sewing machine 10 engages the fork 58 of a pivoted lever 59 and imparts a rising and falling movement to a link 60 connecting lever 59 and the outer element 61 of a conventional one-way clutch 62. This imparts an intermittent, one-way rotary movement to the shaft 63 and through

gears

64 and 65 to the shaft 17 and the cam driving wheel or pinion 20.

The cam-drive motor 16 is connected through the speed reducer 18, one-way clutch 66, and gears 67 and 65 to drive the shaft 17 and the wheel 20 only in the same direction as when driven by the shaft 63. The cam-drive motor in this embodiment is needed only during the 180 degree reversal of the work to starting position during which the sewing machine is inoperative and corresponds to the period represented by the dot-dash line views E, F and A of Fig. 3.

Since the cam-drive motor is always started by energizing the magnetic starter M-l, for the embodiment of Figs. 9 and 10 it is necessary to modify the diagram of Fig. 6 merely by removing the normally-open contacts of relay CR and the normally-closed contacts of relay CRH in series with the starter M-l. These contacts are indicated specifically at c and d in Fig. 6. This change makes the automatic control of the starter M-l responsive only to the relay CR4 which is energized by the timer T-2.

It will be apparent from the above that amost important structural feature of this invention is the position of the drive wheel 20 directly below the needle 21 combined with the presser action of the idler rollers 22-22 to insure that the line of stitches is always in the direction of the normal sewing machine feed at the needle regardless of the changing curvature of the contour path being followed.

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

1. A machine for sewing automatically around a predetermined contour, comprising a sewing machine having a work-supporting surface and a vertically reciprocatory needle, an apertured stationary shelf mounted to form a horizontal extension of the work-supporting surface, a second stationary shelf mounted parallel to and below said first shelf, an annular cam shaped to conform in plan to the predetermined contour to be stitched and supported freely on said second shelf, a pinion projecting upwards through the second shelf and positioned directly below the sewing machine needle in driving contact with one periphery of the annular cam, two spaced idler wheels mounted on a plate spring-biased toward the pinion and bearing on the opposite periphery of the annular cam to maintain driving contact with the pinion, a workholding frame slidingly supported on said first shelf and secured to the annular cam by an element which extends vertically through the aperture in the first shelf, and means for driving said pinion to move the cam and frame so that work held in said frame is moved under the reciprocatory needle to form stitches therein in a path con forming to the predetermined contour.

2. A machine for sewing automatically around a predetermined contour of compound curvature, comprising a sewing machine having a vertically reciprocatory needle, an apertured stationary supporting plate mounted adjacent the needle to form a work support, a second stationary supporting plate mounted parallel to and below said first plate, an annular cam shaped to conform in plan to the predetermined contour to be stitched and supported to be slidable freely on the second plate, a pinion, projecting upwards through the second plate and positioned directly beneath the sewing machine needle, in driving con tact with one periphery of the annular cam, two spaced idler wheels mounted on yielding carriers and bearing on the opposite periphery of the annular cam to maintain proper driving contact with the pinion, a work-holder freely supported to slide on said first plate and operatively connected to the annular cam by a motion-transmitting link which extends vertically through the aperture in the first plate, and means for driving said pinion to move the cam and the work-holder so that work heldtherein is moved under the reciprocatory needle to form stitches in the work in a path conforming to the predetermined contour.

References Cited in the file of this patent UNITED STATES PATENTS 688,961 McDonald Dec. 17, 1901 2,142,476 McDonald Jan. 3, 1939 2,542,126 Everett et a1 Feb. 20, 1951 2,702,016 Reece Feb. 15, 1955 2,722,903 Larkin Nov. 8, 1955