US3543737A

US3543737A - Cam-controlled automatic sewing apparatus

Info

Publication number: US3543737A
Application number: US669118A
Authority: US
Inventors: Hans Maschmann
Original assignee: GM Pfaff AG
Current assignee: GM Pfaff AG
Priority date: 1967-09-20
Filing date: 1967-09-20
Publication date: 1970-12-01
Anticipated expiration: 1987-12-01

Description

United States Patent Hans Maschmann Inventor W. Orange, New Jersey Appl. No. 669,118 Filed Sept. 20, 1967 Patented Dec. 1,1970 Assignee G. M. Pfafl AG Kalserslautern Pfalz Konigstrasse, Germany a corporation of Germany CAM: CONTROLLED AUTOMATIC SEWING APPARATUS 7 Claims, 9 Drawing Figs.

Primary Examiner-H. Hampton Hunter Attorney-Karl Rath ABSTRACT: In automatic sewing apparatus of the type comprising a sewing machine having a reciprocatory needle and a workpiece support displaceable by means of a cam-controlled mechanism operated in synchronism with said machine along a desired path. to sew a seam in accordance withafirst cam section of said mechanism upon a workpiece held by said support, means are providedto drive said mechanism by an auxiliary motor and by way of an overriding clutch in the transmission path between said machine and said mechanism, to displace said support in accordance with at least a second cam section of said mechanism from a point corresponding to the end point of the seam to the starting point thereof, in the case of an interrupted seam or pattern, and/or to and from a workpiece loading position exterior of said machine.

Patentd Dec. 1, 1970 Sheet 1 of s Fig. 2

INVENTOR.

H N5 74S HMANN #40 1. an m A aemsv Patented Dec; 1, 1970 Sheet Q of 3 Fig. 8

INVENTOR.

H4 4/5 NASCHMA A! ATTOQAIEY Patented Dec. 1, 1970 3 ,543,737

INVENTOR.

Hn vs m s w-m/wv 5 mm). mm

A rmemsy CAM-QONTROLLED AUTDMATIC SEWING APPARATUS The present invention conventional sewing to automatic sewing apparatus of the type comprising a conventional sewing machine devoid of an ordinary feed dog or the like feeding device and having a reciprocatory needle cooperating with a workpiece carried by a movable frame or support, the latter being continuously displaced, via suitable motion-transmitting means and along a predetermined path, by a control cam mechanism having a cam configuration corresponding to said path, or the seam to be sewn upon said workpiece, such as a fabric to be operated on.

In automatic sewing apparatus of this type, the movable work-supporting or tentering frame acting as the work feeding means of the machine must be operated in synchronism with the latter, in order to effect a uniform stitch formation, on the one hand, and to ensure an accurate starting and stopping of the seam being sewn, or to produce patterns of uniform shape as well as appearance. For this reason, it is advantageous to I provide a continuously operating main driving motor for the sewing machine and associated cam control mechanism, and

-to control the stitch formation, or starting and stopping of the seam, by means of a mechanical clutch adapted for connecting and disconnecting the drive by said motor. In other words, the driven member of said clutch is idling during the interruption of the stitch formation, or between successive seams or stitching cycles, whereby to ensure a substantially instantaneous starting and stopping of the stitching operation.

Besides, in fully automatic pattern sewing apparatus, it is desirable, in the case of an interrupted seam or pattern, or a seam having an end point different from its starting point, to automatically return the frame or workpiece support either to said staring point, or preferably to a special loading position exterior of the sewing machine to enable easy and proper mounting of a workpiece, and to subsequently return the loaded frame or support to the seam staring position, in respect to the needle, for the commencement of a seam or patterns sewing cycle.

Accordingly, an important object of the present invention is the provision of automatic pattern sewing apparatus of the referred to type by which the sewing goods tentering frame or the like workpiece support is automatically displaced, at the end of a sewing cycle, to a loading position at a point removed from the stitching tools, for the loading of a new fabric or workpiece, the stitch and the subsequently returned, upon manually actuating a starting switch or the like, to the seam starting position, substantially without interference with the sewing operation of the machine.

Another object of the invention is the provision of automatic pattern sewing apparatus of the referred to type including a sewing goods tentering frame or the like workpiece support having an operating path corresponding to a complete operating cycle of the sewing machine and including a loading position exterior of said machine, whereby mutual inter ference between the displacements of said frame during and between, respectively, the stitching cycles is substantially prevented.

Still another object of the invention is the provision of fully automatic pattern sewing apparatus of the referred to type, suitable for the sewing of both interrupted and closed seams, and operation of the workpiece support to and from a separate loading position, which apparatus is both simple in design as well as expeditious and reliable in operation.

The invention, both as to the foregoing and ancillary objects as well as novel aspects thereof, will be better understood from the following detailed description, taken in conjunction with the accompanying drawings forming part of this disclosure and in which:

FIG. 1 is a perspective view of an automatic pattern sewing machine, especially adapted for the sewing of shirt pockets or the like and shown with its cover removed, to reveal the control mechanism disposed above the supporting table of the machine and constructed in accordance with the principles of the invention;

FIG. 2 is a plan view of the machine according to FIG. 1, shown with certain parts omitted for clarity, to indicate the mechanism disposed below the supporting table of the machine;

MG. 20 illustrates, by way of example, the sequential operating steps for the sewing of a shirt pocket during an operating cycle of the machine;

FIG. 3 is an electric wiring diagram for the automatic sewing apparatus shown by the preceding FIGS. FIGS. 4-7 are fragmentary views of the control cams of the apparatus according to the preceding FIGS. explanatory of the function and operation of a complete pocket sewing cycle of the machine; and

FIG. 8 is a partial wiring diagram illustrating a modification of FIG. 3.

Like reference characters denote like parts throughout the different views of the drawings.

With the foregoing objects in view, the invention involves generally the provision, in conjunction with automatic sewing apparatus of the referred to type, comprising a sewing machine and a workpiece carrier or support displaced by means of a cam-controlled mechanism operably connected to and synchronized with said machine, to sew a predetermined seam corresponding to a. partial cam section of said mechanism, of an auxiliary driving motor for said mechanism together with means to automatically connect the same during the interruptions of the seam being sewn, or between successive stitching cycles, to additionally displace the workpiece from the end position to the starting position of the seam being sewn, preferably by way of a separate loading position exterior of or away from the stitch-forming tools, said additional displacement being controlled by a different cam section of said mechanism.

to a preferred arrangement, connection and disconnection of the sewing machine, together with supporting cam mechanism controlling the work fee, and of the auxiliary motor is effected by electrical and mechanical actuating and switch means also controlled by said mechanism, to result in a fully automatic control of an relatively low or stitching cycle upon initially manually starting a sewing cycle by the operation of a starting switch, in a manner as will become further apparent from the following description in reference to the drawings.

Referring more particularly to FIGS. 1 and 2, the numeral 1 represents a supporting table or frame below which is disposed the driving motor 2 of a sewing machine 11, the latter being fitted in a known manner with means, such as interchangeable pole windings (see FIG. 3), for changing from a relatively low to a higher operating speed, and vice versa, said motor being operatively connected, via a V-belt 3 or the like, with a mechanical clutch 4 comprising a first clutch or pulley element 6 freely rotatably and axially slidable mounted upon the outer end of an intermediate shaft 5 rotatively supported by the frame 1, and a second pulley element 7 fast on the shaft 5. The elements 6 and 7 each constitute one half of a split driving pulley and when shifted towards one another firmly engage the belt 3, to drive the shaft 5 in a manner as further described hereafter. The latter further carries at its inner end a pulley 8 which is operatively connected, via a toothed belt 9 or the like, with the driving pulley 10 of the sewing machine ll mounted upon the table 1. The latter may be of conventional construction, except for the omission of the ordinary feed dog or the like intermittent work feeding means.

Further mounted upon the intermediate shaft 5 is a conventional one-way or overriding clutch 12 completely comprising a first coupling element being fixedly supported by said shaft and a second coupling element carrying a pair of rigidly connected pulleys 13 and M. Pulley 13 is connected, via a V-belt or the like l5, with the driving pulley of an auxiliary operating motor 16, while the pulley 14 is connected, via a V-belt or the like l7, a speed reduction gearing 18 and a bevel gear set 19, with a vertical drive shaft 5 rotatively mounted upon the frame 1.

Shaft 20 carries a pair of superposed control cams or

disks

21 and 22 secured thereto in any suitable manner, each of said disks being provided with a

control groove

23 and 24, respectively, of predetermined configuration. Cooperating with or engaging the groove 23 of disk 23 is a cam follower or roller 25 supported by a first angular oscillating lever 26 which is rotatably mounted upon the frame 1 about an axis or spindle 27. Lever 26 is in turn jointed, via a link or connecting rod 28, with one arm of a bellcrank lever 29 rotatively supported by the frame 1 and having its opposite arm fitted with a linear guide 30 in which slides a displaceable rod or push bar 31.

Connected to one end of the push bar 31 is a sewing goods tentering frame or workpiece support 32 adapted to the mounting therein of a workpiece or fabric to be operated on by the sewing machine ii, in a manner described in greater detail hereafter, the oppositeend of the push bar 31 being jointed to an arm of a further bellcrank lever 33 also rotatively supported by the frame i and having its remaining arm jointed, via a link or connecting rod 34, to a further angular oscillating lever 35 rotatively mounted upon the spindle 2'7 and carrying the cam follower or roller 36 cooperating with the groove 24 of disk 22.

Secured to the upper surface of the disk 21 is a pin 37 arranged to cooperate with an arm of a two-arm actuating lever 38 rotatively mounted upon the spindle 27. The remaining arm of the lever 38 acting as a pawl 39 is jointed, by way of a link 46, to one arm of a further double-arm lever 41 rotatively mounted upon the frame 1.

The outer end surface of the pulley element 7 of the coupling 4 is fitted with a circular chamfered braking surface 42 which increases in height in the axial direction and is interrupted by a slot or notch 43. Cooperating with the surface 42 and the slot i3 is a braking shoe or element 44 disposed upon the remaining arm of the lever A l. A tension spring affixed to the lever 41, on the one hand, and to the frame 1, on the other hand, acts to urge the brake shoe 44 against the surface 42, or to cause the same to engage the slot 43, respectively. Further jointed to the control lever 41 is a fork 46 having pair of prongs 4'7 engaging a peripheral groove 48 of the displaceable pulley element 6 of the clutch 4.

Cam disk 22 carries upon its upper surface a pin 49 arranged to cooperate with an arm of a further double-arm actuating lever 50 also rotatively mounted upon the spindle 27 and being connected, by way of a link 51, with an arm of an angular lever 52 rotatable about a horizontal axis and being fitted upon its remaining arm with a ratchet tooth 53 adapted to cooperate with the pawl 39, in the manner described in greater detail hereinafter. A tension spring 54 being affixed to the lever Sil, on the one hand, and to the frame 1, on he the other hand, acts to urge the ratchet 53 in the downward or locking direction, in the manner as will become further apparent from the description of the operation of the device.

Further mounted upon the disk 21 are a pair of concentric sector-

shaped cams

55 and 56, the former arranged to cooperate with a stationary single-throw switch 57, preferably in the form of a toggle or microswitch, and the latter being arranged to cooperate with a stationary double-throw or changeover switch 53. v

FIG. 3 shows the wiring diagram of the control apparatus according to the preceding FIGS. with R, S, T denoting the phases or lines of a three-phase power source and 59 representing a master control switch for the connection and disconnection of the control apparatus.

Connected, in the example shown, to line T of the source is the double-throw switch having a normally closed contact 58a and a normally open contact 5%. Contacts 58a and 581') are both connected to the line S of the source via individual relays tl and (ii, respectively, while the single-pole switch 62, which advantageously has the form of a key or pushbutton {see also Fit}. 5) and die holding switch 57 arranged in parallel to the switch 62 are similarly connectedto lines 8 and T in series with a further relay 63.

As a consequence thespeed-change motor 2 may be fed from the network RST either via switch bile controlled by the relay oil or via switch 61a controlled by relay 61, to rotate the same at low and high speeds, respectively, for the purpose as will become further apparent as the description proceeds. In place of a single motor with separate speed windings a pair of motors may be employed each designed for a fixed 3. different operating speed, as shown by FIG. 8 and described in the following.

The following is a description of the operation of the automatic sewing apparatus described 11 in the foregoing with specific reference to FIGS. 2a 2a and 41-7.

Referring to MG. 20, the tentering frame is shown in three positions, viz. the full line and position 32 during a sewing operation with the seams sewn in the direction marked by arrows a, the starting position 3241 prior to the commencement of a seam sewing operation, and the loading position 3211 for removal of the sewn workpiece and mounting of a new workpiece, respectively.

In the rest or zero position of the device, that is, with the sewing goods tentering frame 32 in the position 321;, FIG. 2a, and with the cam disks 2i and 22 in the position according to FIG. 4, wherein the switch 57 is in the open position, FlG. 3, by engaging a central gap or slot 55' in the cam 55, the double-throw switch 58 engages the contact 58a, as shown in FIG. 3. As a consequence, closing of the main switch 59, to place the device in operating condition, results in the energization of the relay 60 which acts to close the switch 69a, thereby starting the sewing machine motor 2 at its lower operating speed, say 850 r.p.m.,-to drive, via belt 3, the element 7 of the clutch 41 being freely rotatively mounted upon the intermediate shaft 5 In order to start the sewing cycle, that is, the stitching of the seam, shown in the form of a pocket seam by way of example in FIG. 2a, upon the fabric mounted in the frame 32, switch 62 is depressed briefly, whereby to energize the relay 63 and to in turn initiate via a switch 63a rotation of the auxiliary operating motor 16. As a consequence, the latter rotates, via the belt 15, the one-way clutch l2, belt 17, reduction gearing l8, bevel gears 19 and shaft 20, the two cam disks 2i and 22 in the direction of the arrow shown in FIGS. 4-7. Initial starting of the disks 21 results in the actuation of the holding switch 57 running out of the slot 55', FIG. 4, and unto the cam 55, whereby to maintain continued energization of the relay 63 and operation of the motor 16 after release of the pushbutton or the pushbutton or the like starting member 62.

Continued rotation of disk 21 in the direction of the arrow acts to effect, via cam groove 23 and

linkage mechanism

26, 28, 29, 30, the lateral or Y-displacement of the tentering frame 32 and, similarly, rotation of disc 22 acts to effect, via cam groove 24 and

linkage mechanism

35, 341, 33, 31, the iongitudinal or X-displacernent of the frame 32, whereby to effect a composite movement of said frame along a trace determined by the shapes of the grooves 23 and 24). More specifically, during the foregoing rotation of the

disks

21 and 22 by the auxiliary operating motor 16, the frame 32 is displaced from its zero or loading position 3212, FlG. 2a, that is, a position exterior of the sewing machine 11, to the starting position 32a, in which the starting point A of the seam s to be sewn is underneath the needle lla. This displacement is indicated, in reference to point P of the frame, by the dot-dash line marked by arrows c in the FIG.

During the operation of the frame 32 from its loading position 32b FIG. 2a, to the position 32a for the starting of the sewing cycle, the pawl 39 of the double lever 38 is disengaged from or positioned to the left of the ratchet tooth 53 of lever 52, that is, the double lever 41 is deflected in clockwise direction by the action of spring d5, to cause the braking member 443 to engage the slot 43 and to arrest the coupling element "7, while at the same time urging the fork iii towards the right, to disconnect the clutch 4 from the auxiliary shaft 5. Upon arrival of the frame 32 in the starting position 32a of the sewing 'cycle, FIG. 2a, corresponding to the position of the

disks

21 and 22 as shown by FIG. 5, the pin 37 engages and deflects the double lever 38, wherebyto cause the pawl 39 to slide over and to become locked behind the ratchet 53, thereby displacing and locking the link 40 in the position as shown in FIG. 2, that is, releasing the brake element 44 and urging element 6 of the coupling 4 against the belt 3, to start rotation of both the sewing machine 11 and the

cam disks

21 and 22 via shaft 5, pulley 8, belt 9 and pulley 10 on the one hand, and via shaft 5, overriding clutch 12, belt 17, reduction gearing 18, bevel gears 19 and shaft 20, on the other hand. During this operation, the V-belt 3 is clamped between the pulley elements 6 and 7 of the clutch 4, whereby to drive the intermediate shaft by friction between the belt and the element 7. At the same time, the auxiliary motor 16 is arrested by the switch 57 becoming disengaged from the upper half of the sector cam 55, P10. 5, whereby driving of the

disks

21 and 22 is now effected by the sewing machine motor 2 by way of the main clutch 4 and one-way clutch 12 for the sewing of the seam s, FIG. 2a, in the direction indicated by the arrows a and controlled by the

grooves

23 and 24, in the manner readily understood from the foregoing.

The one-way clutch 12 may be of any suitable construction comprising an inner element fast on the shaft 5 and an outer driven element carrying both the pulleys 13 and 14 and unidirectional coupling means effective in allowing of driving connection between shaft 5 and the driven clutch element, while enabling the latter to overrun shaft 5 upon being driven by the auxiliary motor 16. During operation of the

disks

21 and 22 by the motor 2 simultaneously with the operation of the needle No, the auxiliary motor 16 is electrically disconnected from the power source, whereby to idle or rotate freely in being driven via the pulley 13 and belt 15.

Shortly after the starting of a sewing cycle, corresponding to the position of the

disks

21 and 22 as shown in FIG. 6, that is, immediately after the sewing of the first stitches from the starting point A of the seam, FIG. 2a, the sector cam 56, upon its end becoming disengaged from the double-throw switch 58, causes said switch to be disconnected from its contact 58a and to close its contact 53b, whereby relay 60 acts to open the switch 60a and relay 61 actsto close switch 61a, to thereby change the speed of the driving motor from its lower to its higher value, say 1,700 r.p.m., suitable for the effective automatic sewing of the seam s upon the workpiece during a minimum time period by cooperation of the needle 11a with the frame 32 as work feeding means displaced by the action of the

disks

21 and 22 in the manner described and understood.

Shortly before reaching the end B of the seam s, FIG. 20, corresponding to the position of the

disks

21 and 22 as shown by FIG. 7, the sector-shaped cam 56 reengages the switch 58, thus opening the contact 58b and reclosing the contact 58a, whereby to result in the opening of switch 61a and closing of switch 60a, respectively, and in turn a change from the high to the lower operating or sewing speed suitable for the completion of the last stitches of the seam, on the one hand, and in effective braking and stoppage of the sewing machine, free from shock and with the needle in the UP position, on the other hand, as described below.

In the position of the device according to FIG. 7, that is, before reaching the end of the seam during rotation of the sewing machine 11 and disks 21 and 22 a at reduced speed, link 40 remains in the latched or locked position according to FIG. 2. Upon reaching of the end B of the seam, switch 57 is reengaged by the cam 55, whereby to restart'the auxiliary motor 16 which again assumes the drive of the

disks

21 and 22, in the manner described. At the same time, pin 49 by deflecting the double lever 50 against the action of spring 54 acts to disengage, via link 51 and bellcrank lever 52, the ratchet '53 from pawl 39 of the lever 38, whereby to cause the spring 45 to deflect the lever 41, whereby to engage the surface 42 by the braking element did, while at the same time the fork 46 disengages the element 6 from the element 7 of the clutch 4. Upon the member -11 registering with and engaging the slot 42, the sewing machine 11 is finally arrested with the needle 11a in the UP" position. At the same time, the thread may be cut in a known manner by a suitable thread cutting device (not shown). In FIG. 2a, the sewing path proper of the point P of the frame is indicated by the dot-dash line marked by arrows Upon again reaching the initial or zero position 32b by the frame 32 during displacement by the motor 16 from the end position 320 of the sewing cycle, switch 57 by engaging the gap 55' of the cam 55 causes the final stoppage of the motor 16. The sewing goods may now be removed from the frame 32, thus placing the device in position for starting a new sewing cycle by operation of the control switch 62, after a new workpiece has been inserted in the frame 32.

in FIG. 2a, the path of the frame from the end position 32 of the sewing operation to the loading position 321; is indicated by the dot-dash line marked by arrows d.

FIG. 8 shows an alternative way to change from a high operating speed to a low' operating speed of the sewing machine, and vice versa, the arrangement shown differing mainly from that according to FIG. 3 by the provision of two

separate driving motors

2a and 2b being controlled by the

switches

60a and 61a in the same manner as in the preceding embodiment. Both motors having low and high operating speeds are drivingly connected with one another via

pulleys

65 and 66 and a belt 3a, while one of the motors, that is, motor 2!) in the example shown, serves to drive the sewing machine via belt 3 in the manner shown by FIG. 2. During operation, the deenergized or idle motor is driven freely by the other or driving motor, and vice versa, in the manner readily understood.

While in the foregoing the invention has been described in conjunction with the sewing of shirt pockets, it will be understood that seams or patterns of different configuration may be produced automatically and economically by means of sewing apparatus of the type according to the invention.

In the foregoing, the invention has been described in reference to a specific exemplary device. It will be evident, however, that a variations and modifications, as well as the substitution of equivalent parts or devices for those shown and s described herein for illustration, may be made without departing from-the broader scope and spirit of the invention. The specificationand drawings are accordingly to be regarded in an illustrative rather than a restrictive sense.

I claim:

1. Automatic sewing apparatus comprising in combination:

1. a sewing machine having a reciprocable needle;

2. a drive shaft for said machine:

3. a continuously running high-speed driving motor;

4. a main clutch including a driving element in operative driving connection with said motor, a driven element in operative connection with said shaft, and a control element to operate said driven element into and out of engagement with said driving element for the starting and stopping of said machine;

. a tentering frame to hold a workpiece to be operated on by said needle',

a pair of rotating coaxial cams and cam follower means therefor disposed substantially independently of the sewing machine and motion-transmitting means operably connecting said follower means with said frame, to dis place said frame in coordinate directions, to produce a total operating path thereof determined by the configuration of said cams;

7. further motion-transmitting means connecting said drive shaft with said cams including an auxiliary overriding clutch having a driving element and a driven element, to drive said cams in synchronism with said machine for the sewing of a corresponding seam upon said workpiece during a fractional part of said path;

8. an auxiliary low-speed driving motor operably connected to said auxiliary clutch, to drive said cams independently of said drive shaft during disconnection of the sewing machine from said main driving motor by said main clutch; and

9. cooperating stationary actuating means upon said cams and switching means operated thereby and controlling said control element and said auxiliary motor, to disconnect said machine by operation of said control element and to start said auxiliary motor to drive said cams upon the latter reaching a predetermined position at the end of a sewing cycle, for displacing said frame by said cams and said auxiliary motors between successive seam sewing cycles.

2. in automatic sewing apparatus as claimed in claim 1, each of said cams including a first section having a configuration to displace said support through an operating path for the sewing of a predetermined seam having starting and end points corresponding respectively to predetermined first and second angular positions of said cams, and a second cam section following said first cam section, to displace said support, upon stopping of said machine at the end of said seam by said main clutch, through a return path to said starting position by continued rotation of said cams from said second to said first angular position by said auxiliary motor.

3. in automatic sewing apparatus as claimed in claim 2, said return path of said support including an intermediate loading position exterior of said machine.

4. Automatic sewing apparatus comprising in combination:

1. a sewing machine having a reciprocatory needle;

2. a drive shaft for said machine; 3. a continuously running high-speed driving motor for said machine;

4. a main clutch including a driving element in operative driving connection with said motor, a driven element in operative connection with said shaft, and a control element to operate said driven element into andout of engagement with said driving element for the starting and stopping of said machine;

5. a tentering frame to hold a workpiece to be operated on by said needle;

6. a pair of rotating coaxial cams and cam follower means therefor disposed substantially independently of the sewing machine and motion-transmitting means operably connecting said follower means with said frame, to displace said frame in coordinate directions, to produce a total operating path of said frame determined by the configuration of said cams;

7. further motion-transmitting means connecting said drive shaft with said cams including an auxiliary overriding clutch having a driving and a driven element, to drive said cams in synchronism with said machine, for sewing of a corresponding seam upon said workpiece;

8. an auxiliary low-speed driving motor operatively connected to said auxiliary clutch, to drive said cams independently of said drive shaft during disconnection of the sewing machine from said main driving motor by said main clutch; and

9. cooperating actuating means upon said cams and switching means operated thereby and controlling said control element and said auxiliary motor, to automatically effect, in the order named, the sequential operations of displacing said frame, starting from a loading position exterior of said machine and upon manually starting said auxiliary motor, to a seam starting position over a path controlled by a first section of said cams, of arresting said auxiliary motor and simultaneously connecting said shaft to said main driving motor by said main clutch, to effect the sewing of a seam upon the workpiece controlled by a second section of said cams following said first section, and of disconnecting said drive shaft from said main driving motor by said main clutch upon reaching the end position of said seam and simultaneously restarting said auxiliary motor, to displace said frame to said loading station over a path controlled by a third section of said cams following said second section.

5. in automatic sewing apparatus as claimed in claim a, in-

cluding control means to chan e between a relatively low and relatively high operating speed of said mam driving motor and actuating means therefor controlled by said cams, to temporarily reduce the sewing speed during relatively brief starting and end periods of the seam being sewn.

6. in automatic sewing apparatus as claimed in claim 4, said control cams being comprised a pair of cam disks having a common drive shaft and said motion-transmitting means being mutually operably interconnected between said cams with said support, both said disks having cam configurations to result in displacements of said support in a pair of rectangular coordinates.

7. Automatic sewing apparatus comprising in combination: 1. a sewing machine having a reciprocatory needle:

2. a continuously running high-speed main driving motor therefor;

3. controllable mechanical coupling means between said machine and motor, to selectively connect and disconnect, said machine, for effecting a sewing operation;

. a tentering frame to hold a workpiece to be operated on by said needle;

5. control means including a pair of coaxial rotating cams in operative driving connection with said machine, cam follower means and motion-transmitting means operatively connecting said follower means with said frame, to displace said frame in coordinate component directions in accordance with the configurations of said cams, for the sewing of a seam conforming with the path of said frame;

6. an auxiliary low-speed driving motor; and 7. means including an overriding clutch in said motiontransmitting means to rotate said cams by said auxiliary motor upon stoppage of said machine by operation of said coupling means, to automatically displace said by frame by said auxiliary motor to a loading position exterior of said machine upon completion of said seam.