US3434439A

US3434439A - Material stitching and guiding apparatus

Info

Publication number: US3434439A
Authority: US
Inventors: Ragnar W Winberg
Original assignee: RAGNAR W WINBERG
Current assignee: RAGNAR W WINBERG
Priority date: 1967-12-16
Filing date: 1967-12-28
Publication date: 1969-03-25
Anticipated expiration: 1986-03-25
Also published as: GB1197489A

Description

sheet of 4 R. W. WINBERG vPviATERIALI STITCHING AND GUIDING APPARATUS March 25, 1969 Original Filed May 31, 1966 v In www 1 f. 11 5 NN %& 4 Nw $4 G n ....Kn?. L l u ii o N v 0 .&\\ E 4 n QN N .4 s N IU. .mv QN NQ rlw l "I o Il! Il. n NQ lm G \N$ Q 4. SPG 4 N\o\ NQ Sx Al N NC Il MN Ilm. $4 x Nm. Nw.

March 25, 1969 R. w. WINBERG 3,434,439

MATERIAL STITCHING AND GUIDING APPARATUS BY :g (37 aim March 25, 1969 R. vv. WINBERG 3,434,439

MATERIAL STITCHING AND GUIDING APPARATUS original Filed May :51, 196e sheet 3 of 4 INVENTOR.' ,M6/VA@ M ll//frw March 25, 1969 R. w. WINBERG MATERIAL STITCHING AND GUIDING APPARATUS Sheet FIG. 4.

Original Filed May 31, 1966 FIG. 5

INVENTOR @4m/4,@ W. fm/@M6 @Tram/FYI 3,434,439 MATERIAL STlTCHlNG AND GUDTNG APPARATUS Ragnar W. Winherg, 115 W. Elder Ave.,

This is a continuation of application Ser. No. 553,783, filed May 31, 1966.

The present invention relates generally to sewing apparatus, and in particular to a machine for stitching one or more plies of material along a stitch line coextensive with and spaced from the edge of a material assembly. Advantageously, the present machine finds useful application in the stitching of superposed pieces of material together along curved or contoured edges, as may be required in the manufacture of a wide variety of articles of manufacture, and in particular in mens and womens wearing apparel.

In various stages of apparel manufacture, it becomes necessary to join superposed pieces of material together along a stitch line which is spaced inwardly from the coextensive edges thereof. Usually, the machine operator matches up the superposed edges and then feeds the same through the sewing machine while continuously guiding the material to assure stitching along a line uniformly spaced from the superposed edges to provide the required selvages or margins outwardly thereof. Attempts have been made to modify conventional sewing machines to facilitate the semi-automatic or completely automatic feed of material thereto to thereby eliminate or reduce the need for an operator in constant attendance. For a wide variety of reasons, which are well understood by those skilled in this art, such equipment has found only very limited usefulness and in most instances has been confined to straight line stitching of continuous lengths of material or the stitching of large quantities of an assembly which requires the same repetitive pattern.

There exists a need for semi-automatic or automatic stitching equipment which enables the joinder of superposed plies of material along a prescribed course, whether the same be curved or straight. It would be particularly advantageous if such equipment could be useful for either short or long runs so as to be able, by relatively simple adjustment, to handle the various stitch lines which are required from day to day in a typical manufacturing operation. For example, in a garment factory, and even when conned to the stitching of a single type of garment, there are seams which, depending upon the style and size of the garment, will vary in both length and curvature. Even when merely switching from one garment to another, or from one size of garment to another, different stitching conditions are presented. For a machine of this type to acquire widespread acceptance, it is essential that the same be readily adaptable to the new conditions. Of paramount importance, is the capability of the machine to complete a stitch line which has the various desirable attributes of one stitched by a skilled machine operator.

In copending application Ser. No. 275,297 filed on Apr. 24, 1963, now abandoned, and copending application Ser. No. 556,535 filed May 20, 1966, now Patent No. 3,322,081, the latter application being a continuation of the former and both entitled Material Stitching and Guiding Machine there is disclosed a semi-automatic sewing machine which exhibits the requisite capablities for stitching of superposed plies of material along a stitch line which stitch line closely follows the curvature of the coextensive edges of the superposed plies and is 3,434,439 Patented Mar. 25, 1969 substantially uniformly spaced therefrom. Such apparatus embodies a conveying and guiding mechanism for bodily advancing the material assembly, be it one or more plies, to a work location while continuously orienting the assembly in accordance with the contour of the edge along which the stitch line or seam is required. The conveying and guiding mechanism includes a conveyor which is arranged to underlie and engage the material and to advance the same along a feed path toward the work location. An elongated flexible cam member is arranged substantially along one side of the feed path and is adapted to be secured in a prescribed configuration relating to the contour of the edge of the material. The cam member is engaged by a cam follower which is movable therealong, with provision for engaging the material with the cam follower such that the material is steered in accordance with the prescribed configuration of the cam member to displace the material in relation to the feed path while the same is being bodily advanced toward the work location by the conveyor. The flexible cam member is reconfigured from time to time in accordance with the particular edge configuration and may be changed over by the machine operator in relatively short order and without undue difficulty. Experience with this type of equipment indicates that still greater Versatility may be imparted to the equipment if it were possible to steer the cam follower or clamp by a cam member or track which did not require physical resetting each time a different set of stitching conditions were encountered. The realization of this further desirable attribute would make it a relatively simple matter for a relatively unskilled machine attendant to almost instantaneously change over from stitching conditions requiring a given length and given contour to a different length and/or different contour. Thus, it would be possible to employ the same equipment for stitching, in succession and with the relatively short change over time, a curved seam for a sleeve, a somewhat straighter and longer seam at the inside or outside of a trouser leg and the enumerable other stitching conditions which are encountered on a day to day basis in this one field. The versatility and adaptability of the present invention to automating operatorcontrolled and guided stitching equipment will be apparent to those skilled in the art as the instant description proceeds.

It is an obje-ct of the present invention to provide automatic sewing apparatus which realizes one or more of the aforesaid objectives. Specifically, it is within the contemplation of the present invention to provide a feeding and guiding mechanism which may be operatively arranged relative to a conventional sewing machine head and permits the stitching of one or more plies of material along a stitch line which closely follows the contour of the material edge and is in proximity thereto.

In accordance with an illustrative embodiment demonstrating objects and features of the present invention, a machine is provided for stitching material along a prescribed stitch line coextensive with and spaced inwardly from an edge thereof which comprises a support. Sewing mechanisms are mounted on the support and include the usual reciprocating needle operable at a stitching location for successively stitching the material along a prescribed stitch line. The material is arranged forwardly of the stitching location and advanced toward and through the stitching location along a normal feed path relative to the needle, as by the provision of a conveyor. Guide means are engageable with the material and operable to impart steering motion to the material as the same is advanced toward the stitching location for displacing the material from side to side relative to the normal feed path such that the material will be stitched substantially along the stitch line and in uniform spaced relation to the adjacent material edge. The guide means includes an elongated guide rail or track projecting forwardly of the needle and a clamp movably mounted on and guided by the rail. The guide rail is mounted on the support for movement relative to the normal feed path, with the clamp being engageable with the material contiguous to the trailing end of the contoured edge when the leading end of such edge is initially positioned at the stitching location. Means are provided, preferably in the form of photocells, which are responsive to the deviations of the edge relative to the normal feed path for moving the guide rail in a direction to restore the edge to the proper oriented position for continuous stitching along the prescribed an-d stitch line. The guide rail is effective in response to its movement to impart a corresponding steering motion to the clamp as the latter is moved therealong and toward the stitching location to continuously orient and properly present successive edge-adjacent portions of the material in relation to the stitching mechanisms for stitching along the prescribed stitch line. In a typical illustrative machine, the elongated guide rail is rigid and is mounted on the support for pivotal movement, with the photocells constantly monitoring the position of the guide rail and pivotally adjusting the same such that the material edge contiguous to the stitching location will always be in proper relation to the needle for stitching along the prescribed stitch line.

The above brief description, as Well as further objects, features and advantages of the present invention will be more fully appreciated by reference to the following detailed description of a presently preferred, but nonetheless illustrative embodiment in accordance with the present invention, when taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a plan view of a stitching machine embodying features of the present invention, shown with a typical material assembly in position for feed therethrough and with parts broken away and sectioned to reveal constructional details;

FIG. 2 is a side elevational view of the machine;

FIG. 3 is a schematic and diagrammatic representation of the controls employed in the present machine, with the controls shown in the rest condition of the machine;

FIG. 4 is a partial showing of the control shown in FIG. 3, illustrating the running condition `of the machine; and,

FIG. 5 is a partial view similar to FIG. 4 likewise showing a further condition of the machine during restoration to the FIG. 3 position.

Referring now specifically to the drawings, there is shown a material guiding and stitching machine, generally designated by the reference numeral l0, which is suitable for the stitching together of superposed plies or pieces of materials M having a curved or contoured edge e. Although a single ply of materials is illustrated in the drawings, it will be appreciated that this is intended to be merely representative of the various single pieces or multiple ply assemblies which may be stitched with the present apparatus. Although the sewing machine will be recognized as being a typical lock stitch sewing machine, it will likewise be appreciated that various types of commercially available sewing apparatus may be employed in accordance with the present invention. Finally, although emphasis is placed herein on automatic stitching for the garment or wearing apparel industry, it will be appreciated that the invention find application in many other fields.

The machine includes a support or frame 12 having a horizontally extending feed bed or table 14 providing a large work-supporting surface. Mounted on the support 12 across one end thereof is a sewing machine, generally designated by the reference numeral 16, which may be a typically `drop-feed lock stitch sewing machine of the type manufactured by Singer Machine Company. The illustrative sewing machine 16 includes a machine body 1S having an upstanding head section 18a and an elongated body section 18b. Extending longitudinally of the machine body 18 is its main drive shaft 20 which serves to motivate the usual sewing machine mechanisms including the vertically reciprocating needle bar 22 having the needle 24 and the associated bobbin and bobbin raceway and other known machine components. Disposed rearwardly of the needle bar 22 is the usual presser foot bar 26 which carries the presser foot 28 which coaets with a feed dog (not shown) in a usual fashion. Drive is imparted to a main drive shaft 20 from a drive motor 30 which is disposed beneath the table or feed bed 14 (see FIGS. l and 2). The motor output shaft 30a carries a driving pulley 32 which is coupled by a belt 34 to driven pulley 36 on the main drive shaft 20. As seen in FIG. l, the drive motor 30 is selectively coupled to and decoupled from the driving pulley 32 by clutch 38 (shown in disengaged position) which is engaged and disengaged by a double arm clutch-actuating lever 40 pivoted on the motor housing at 42 by bracket 44. Arm 40a of the clutch-actuating lever 40 is bifurcated and engages a clutch actuating pin 33a, and arm 40h is connected to the piston rod of a clutch-control piston and cylinder C5. The clutch-control piston and cylinder C5 is of the single acting springbiased type. Upon the introduction of air into the cylinder, the piston rod is extended to rock the lever 40 in a direction to engage the clutch; and upon porting of the cylinder to atmosphere, the internal spring of the cylinder and piston C5 restores the clutch 38 to its disengaged position. Further description of the clutch control and the coordination of the stitching mechanisms by the usual sewing machine parts within the body 18 is dispensed with since these are well known to those skilled in the art.

Disposed rearwardly of the presser foot 28 is a rotary puller wheel 46 which is arranged along the normal feed path of the material M through the sewing machine and directly behind the presser foot 28. The rotary puller wheel 46 supplements the feeding action of the usual four-motion lfeed dog in the sewing machine which, for the present purposes, is usually insufficient to rapidly advance the material M past the stitching location afforded by the needle 24. The puller wheel 46 is connected by an appropriate flexible coupling shaft 47 to a puller drive shaft 48 which is disposed rearwardly of the sewing apparatus and is journalled on

appropriate standards

50, 52. The puller drive shaft 48 carries a relatively large diameter driven pulley 54 which is coupled via belt 56 to a drive pulley 58 on the sewing machine main shaft 20. The drive pulley 58 may be of the adjustable diameter type to permit variations in the drive from the main drive shaft 20 to the rotary puller 46. For further details of this type of rotary feeder, reference may be made to U.S. Patent No. 2,777,409 of Ian. 15, 1957 entitled Feed Means for Sewing Machines.

Extending lfore and aft of the machine 10 is a conveyor 60 which includes plural side by side endless belts 62, 64, 66. The upper courses of the belts 62, 64, 66 overlie the feed bed .14 and are arranged to underlie the material M for advancing the same along a normal feed path toward the stitching location at the sewing machine 16. Thus, during a typical stitching interval, successive edge-adjacent portions of the material M are presented to the stitching mechanisms including the needle 24 and the presser foot 2% at the stitching location for joinder. The endless belts of the conveyor 60 are trained over aligned pairs of pulleys (i.e., pulleys 68, 70 for belt 66) which pulleys are secured respectively to conveyor pulley shafts 72, 74 extending transversely of the machine. The shaft 72 is journalled on appropriate brackets (i.e., bracket 76 depending from feed hed 14) at a location rearwardly of the sewing machine and receives drive from the motor 30 via worm 78 on shaft extension 72a which is coupled to worm gear Btl which in turn is driven by bevel gear 82 on shaft 4S. Thus, upon rotation being imparted to shaft 48 for driving the puller wheel 46, corresponding rotary movement is imparted to the conveyor drive shaft 72 via gearing 82, 80, 78 to activate the conveyor 60. It will be appreciated that the variable speed pulley 58 incorporated in the coupling arrangement to the sewing machine motor 30 affords a convenient means for adjusting the rate of advance of the material M under the influence of the multiple belts 62, 64, 66 of the conveyor 60.

Overlying the feed bed or table 14 of the machine is a material-guiding assembly, generally designated :by the reference numeral 84, which is engageable with the material M and is operable to impart steering motion to such material as the same is advanced toward the stitching location. By displacing the material from side to side relative to the normal feed path, it is possible to establish stitching along any requisite stitch line. A portion of a typical stitch line, designated by the numeral 86, is illustrated and is seen to be parallel to and spaced inwardly from the contoured edge e of the material M. The conveyor 60 serves to advance the material M along a straight line feed path appropriate for stitching along and spaced inwardly of a material edge which is parallel to the linear feed established by the conveyor. However, the material guiding assembly 84, which will now `be described, serves in conjunction with the conveyor 60 to steer the material M in a manner closely simulating the guiding action imparted to the material under the influence by a machine operator when confronted with the problem of stitching along a ocntoured or curved edge e, yet does so on an automatic basis and to an order of accuracy and repeatability which is virtually unobtainable by a machine operator.

The material guiding assembly 84 includes an elongated straight and substantially rigid guide rail or track 88 which projects forwardly from the stitching location and is intended to overlie the table 14 and the upper courses of the plural belts of the conveyor 60. The guide rail or track 88 is mounted on the support 12 for movement relative to the normal feed path established by the plural belts of the conveyor 60. In this illustrative arrangement, the guide rail 88 is mounted for pivotal movement about a vertical pivot and in a horizontal plane generally spaced above the table 14. Specifically, appropriate bracketing 90 is secured to the machine body 18 to provide a vertical pivot in alignment with and rearwardly of the needle 24 (see FIG. l). The guide rail 88 is suspended above the feed bed 14 for side to side swinging movement about pivot 92 by an adjustable mounting arrangement which permits the rail to be laterally adjusted relative to the -vertical pivot 92, for reasons to be subsequently described. Specifically, the mounting arrangement includes an L-shaped mounting bracket 94 which is appropriately configurated at one end to provide a support for the guide rail or track 88 and is formed at its opposite end with a transverse mounting sleeve 96 which is confined between two

collars

98, 100 attached to a lead screw 102. The lead screw 102 is received within an internally threaded sleeve 104 which in turn is journalled on the vertical pivot 92. The lead screw 102 is manipulated by a knurled adjustment knob .106. Accordingly, upon turning of the adjustment knob y the lead screw 102 may be threaded in and out relative to the sleeve 104 and the pivot 92 to initially adjust the starting position for the guide rail 88.

Mounted on the guide rail or track 88 is a clamp assembly 108 which includes a spring-biased clamp which is adapted to engage the trailing end of' the material M along and spaced slightly inwardly of the contoured edge e for the coordinate guiding function with the conveyor 60. The clamp assembly 108 is seen to include a trolley or carriage 110 which includes plural rollers 112:1, 11211, 112e engaging the upper and lower guiding surfaces of the track or rail 88. Depending from the trolley 110` is a clamp-supporting bracket 114 which carries at its lower end a horizontally extending abutment plate 116 which is adapted to be brought beneath the trailing end of the material M. Overyling the abutment plate 116 is a stripper plate 118 through which projects a clamping pin 120 which is mounted on a double arm clamp-supporting lever 122 which is pivoted on bracket 114 at 124. Arm 122a extends substantially horizontally over stripper plate 118 and carries the clamp pin 120 which extends through and engages the material M, while arm 122b extends generally upwardly and is connected to the plunger of a clampcontrol solenoid SL. A spring 126 is connected to arm 12211 and to bracket 114 to normally bias the clamp 120 into its operative or material-engaging position. Solenoid SL is effective to overcome the bias of the spring and to urge the clamp 122 to a clearance position enabling the trailing end of the material to be inserted within the clamp overlying the abutment 116 and in position for engagement by the pin at the start of a stitching interval or sequence and to be released at the end of the stitching interval.

In order to assure smooth operation of the clamp assembly 108 mounted via trolley 110 on rail 88, provision is made for counterbalancing the clamp assembly such that the pulling force exerted by the puller roller 46 and the usual feeding mechanisms in the sewing machine will permit the unimpeded feed of the material M through the sewing machine for stitching. To this end, a counterweight 128 is provided beneath the machine which is connected via cable 130 and

idler pulleys

132, 134, 136 to the trolley 110 of the clamp assembly 108. By appropriate selection of the weight 128, a rather delicately balance system can be established which will respond instaneously and which will not adversely effect the material (i.e., by stretching the same) notwithstanding the mass of the clamp assembly 108.

Provision is made for propelling the clamp assembly 108 along the guide rail 88 out of an adjustable starting position toward its finishing position. Conversely, provision is made for propelling the clamp assembly 180 back to the starting position at the end of the stitching interval and after the release of the material M by the clamp pin 120. Specifically a first clamp-propelling piston and cylinder C4 is disposed behind the trolley 110, with the piston carrying an enlarged head 138 which is arranged to engage and push the trolley 110 along the track 88 toward the sewing machine 16. This piston and cylinder is adjustably mounted on the rail by the provision of a supporting shoe 140 which may be fixed tothe rail by locking member 1-42. At the other end of the guide rail 88 forwardly of the sewing machine head 18 there is arranged a second clamp-propelling cylinder and piston C3 which has an enlarged head 144 in position to engage the trolley 110 and return the same to the starting position upon the completion of the stitching interval, as will be subsequently described.

Provision is made under the control of the machine operator for initiating a stitching interval during which the clamp assembly 108 moves from the adjusting position remote from the needle 24 to the finishing position adjacent the needle. Further means including a signaling switch SS are provided which respond to the movement of the clamp assembly 108 into the finishing position for concluding the stitching interval. These controls will be described in conjunction with the detailed description of FIGS. 3 to 5 inclusive.

The spring-biased presser foot 28 of the sewing machine normally is disposed in its operative position but is held in an elevated position for the loading of the machine prior to the initiation of the stitching interval. This is accomplished by a piston and cylinder C1 which is mounted rearwardly of the sewing machine head (see FIGS. l and 2), with the piston rod thereof coupled via linkage 146 to internal mechanisms on the sewing machine which, upon operation of the piston and cylinder C1, lift the presser foot 28 to the elevated loading position.

Still further, a cutter 148 is disposed rearwardly the presser foot and the puller wheel 46. The cutter 148 is mounted on a cutter mount 158 pivoted on the bed plate at 152 and is movable at the end of a stitching interval from the retracted position illustrated in FIG. l to an operative position directly behind the puller wheel 46, as indicated by the directional arrows, for severing the stitching thread which normally interconnects successive completed stitch material assemblies. The cutter 48 is moved from its normal inoperative position to the operative position under the control of the cutter-activating cylinder and piston C2 at the end of the stitching interval at which time the presser foot is raised to release the work.

Disposed forwardly of the needle 24 are a pair of spaced photocells P1, P2 which are mounted in a barrel rotatable about a vertical axis for positioning thereof relative to the optimum line of advance of the edge e relative to the stitching mechanisms. As will be described, the photocells P1, P2 serve to position the guide rail 88 to impart the requisite steering motion to the clamp assembly 108 during the stitching interval. Between the photocells P1, P2 and the needle 24 there is provided in the feed bed of the machine two ports 154 which are connected via flexible pipes 156 (see HG. 2) to an appropriate vacuum source such that the material assembly is held down in critical location in advance of the needle 24.

Provision is made for pivoting the guide rail 88 about its vertical pivotal mount 92 in accordance with the signals derived from the photocells P1, P2 during the stitching interval and for manually adjusting the position of the guide rail 88 at the start of a stitching interval. These mechanisms are coordinated into the control illustrated in FIG. 3, with the control having the capability to sense the initial adjusted position of the guide rail S8 as established by the machine operator and to restore the guide rail to such adjusted position at the end of each stitching interval. In this way, once the operator establishes the initial starting position for the guide rail for any particular stitching operation, the guide rail automatically is restored to that initial starting position. Therefore, it is merely necessary to reload the equipment at the end of each stitching interval for the next stitching operation, notwithstanding the fact that the rail has moved out of the requisite starting position during the stitching interval to impart the necessary guiding action to the material assembly. This arrangement includes a double acting rail-adjusting cylinder and piston C6 which is disposed beneath the feed bed of the machine and suspended from the support 12 thereof at pivotal mount 158. The piston rod carries a bifurcated yoke 160 which is coupled Via arm 162 to a vertical pivot shaft 164 which extends upwardly through the machine frame 12 to a location above the work-supporting surface afforded by the feed bed 14. Arm 162 has a pivotal connection 166 to the yoke 169 on the piston rod at one end thereof, with the other end being rigidly connected to shaft 164. Shaft 164 at its location above the feed bed carries a rigid steering arm 163 which follows the motions imparted to arm 162 under control of the cylinder and piston C6. Steering arm 16S has a pivotal connection 170 at its end remote from shaft 164 to one end of a steering link 172 which has a pivotal connection 174 at its opposite end to rail extension 88a. Rail extension 88a carries a supporting roller 176 which rides upon the work-supporting surface 14. It will thus be appreciated that upon driving the piston toward the right in FIG. l, steering arm 168 will be swung in a counterclockwise direction thereby swinging the guide rail 88 in the counterclockwise direction about its pivotal mount 92. Conversely, upon driving the piston to the left in FIG. l, clockwise motion will be imparted to the steering arm 16S, with a corresponding clockwise pivotal movement being imparted to the guide rail 8S. Air is introduced into the opposite ends of the rail-adjusting cylinder and piston C6 by the control, as will be described.

Manual adjustment of the position of the guide track or rail 88 is accomplished by the provision of a track or rail positioner TP which is disposed at a convenient location to one side of the machine and is seen to include an adjustment handle 178 and a track position dial 180 having two arcuate conductive segments TPa, TPa. The dial 18@ of the track positioner TP is journalled on an upstanding shaft 182. The adjustment handle 1'78 is tapped through the dial 1&0, and upon turning in the appropriate direction, permits the securement of the dial 180 in any adjusted position on shaft 182. Journalled on the shaft 182 above the disc 180 is a track positioner sprocket 184 which carries a contactor TPa which normally is intended to maintain a neutral position between the conductor segments TPa and TPa, as shown mechanically in FIG. 1 and diagrammatically in FIG. 3. However, as such times that contactor TPa is on one or the other of the conductive segments TPa, TPrz and the track positioner TP is in its operative mode, the control arrangement is such as to restore the contactor to the neutral position with the corresponding movement of the guide rail 88 to the adjusted position established in the first instance by the rotational adjustment of the dial 180 of the track positioner TP under control of the operator. Sprocket 184 is coupled via chain 186 to driving sprocket 188 on intermediate shaft 164. Thus, the rotational movement imparted to the intermediate shaft 164 under control of the cylinder and piston C6 to achieve steering motion of the rail will be read into the track positioner TP via driving sprocket 188, chain 186 and driven sprocket 184.

It may be desirable to supplement the holding effect of the vacuum ports 154 by the provision of air jets directed downwardly on the material at a location overlying the vacuum ports 154. This may be accomplished by the provision of two jet pipes 190 directed downwardly toward the ports 154 which pipes are connected via conduit 192 to an appropriate source of air under pressure (i.e., a small blower).

Turning now specifically to FIG. 3, there is shown a typical control in schematic and diagrammatic form for use in connection with the present apparatus. The various components of the machine which are integrated into this control are shown schematically to facilitate an understanding of the operation of the control. The control includes

main input lines

192, 194 which are connected to an appropriate source of power over main switch MS in line 192. Associated with each of the several piston and cylinders are appropriate solenoid-controlled valvef for connecting the respective pnuematic actuating means t a source of air under pressure for the related contro: functions. Specifically, solenoid control valve V1 connects the main air line 196 to both the cylinder and piston C1 for the presser foot 28 and the cylinder and piston C2 for the cutter 46. V1 is energized over nominally closed contact Ria of a delay action relay R1 which has its energization coil connected across the lines over contacts R2a, R2a of relay RZ. Relay R2 in turn has its energization coil connected across the lines of a first foot control switch PS1 and interval-end or stop switch SS. In the rest position of the equipment, presser foot 28 is held in its elevated position by activation of cylinder C1 and correspondingly the cutter 46 is held in its operative position by its cylinder C2. Upon opening of contact Rla in response to energization of relay R1 under control of relay R2, the presser foot 28 moves into its operative position and the cutter 46 moves into a retracted or clearance position.

Relay R2 includes contact R2a which transfers onto contact R2a to condition the energization circuit for relay R3 over a second foot control switch PS2. Relay R2 includes a holding contact R211 which is closed upon energization of the relay R2 under control of the first foot control switch FSI to enable the machine operator to remove his foot from switch F81 after initiating the first sequence of operations, to wit, the dropping of the presser foot 28 into the operative position and the movement of the cutter 46 away from the stitch path. Relay R3, which is energized in response to closing of the second foot control switch PS2, includes a first contact R3a which is normally against contact R3a but is transferred onto contact R3a. In the rest position of the equipment, contact R3a completes an energization circuit for the solenoid SL which normally maintains the clamp pin 124i in its retracted position. Relay R3 includes holding contact Rb to complete a holding circuit therefore which enables the operator to remove his foot from switch FS2 after initiating this phase of the operation. Thus, after the operator has depressed foot switch FSI to clamp the lpresser foot against the work load therebeneath, the operator then appropriately positions the material assembly relative to the clamp 120 and depresses foot switch FSZ to complete the clamping of the fabric. Transfer of contact R3a from contact R3a' restores the clamp-return cylinder C3 which is activated over solenoidcontrolled valve V2. The establishment of the circuit over contact R3a, R3a operates solenoid-controlled valve V3 which actuates the clutch control C and the clamp starting cylinder C4.

Closing of the second foot switch F82, which signals the beginning of a stitching interval, energizes relay R4 which transfers the contacts thereof to disable the track positioner TP and establishes the required Contact to place the rail-adjusting cylinder C6 under control of the photocells P1, P2.

Turning now to the track selector TP, as previously described the adjustable dial 18() has two conductive segments TPa', TPa" which are engaged by contacter or slider TPa, with the movement of the contactor being linked to the movement of the guide track 88. Contacter TPtz is normally connected over contact R4a, R4cz of relay R4 to line X of relay A1 having normally closed contact Ala. The photocell P1 is seen connected to relay A1 at line X and is connected to line X over contact R4a" of relay R4. Thus, in the illustrated position, relay A1 is under control of the contactor TPa of the track positioner TP. Upon transfer of con-tact R411 against contact R4a in response to energization of the relay R4, the track positioner TP is `disabled and the photocell P1 serves as the input to relay A1. When contactor TPa is on conductive segment TPcz', line X and X are connected to each other to activate relay A. However, upon transfer of Contact R4a into engagement with contact R4a, photocell P1 takes over and when exposed to light comple-tes a circuit across lines X, X to activate relay A1. In a similar fashion, relay A2 is under control of the track positioner TP via segment Tla" and photocell P2. Relay A2 includes a first contact A2@ which is normally closed and establishes an energization circuit for solenoid-controlled valve t V5 over contacter R411' or relay R4. Relay A2 further includes contact A2Z) which is normally open and upon energization of the relay establishes a secondary energization circuit for solenoid-controlled valve V5 over contact 44b, R4b" of relay R4, the latter being energized to disable the track positioner TP. In the illustrated position, track positioner TP establishes a circuit across lines Y, Y at such time as contactor TPa is on conductive segment TPa to disrupt the energization circuit for solenoidcontrolled valve V5 and thereby bleed off port the corresponding right side of the rail-adjusting cylinder and piston C6. By way of summary, when the track positioner TP is in control (relay R4 deenergized), the rail-adjusting cylinder and piston C6 is appropriately ported to atmosphere and activated by solenoid-controlled valves V4, V5 to restore the contactor TPa to the neutral position illustrated in FIG. 3. This may be appreciated by reference to FIG. 5 wherein a typical position of contactor TPcz on segment TPa" is illustrated, it being noted that the relay R4 is not energized such that the track positioner TP is in control of the rail-adjusting cylinder and piston C6. For this illustrated condition, a circuit is established to cross the lines Y, Y -transferring the contacts of relay A2 to disrupt the energization circuit for solenoid-controlled valve V5 over open contact A2a. Closing of contract A2b has no effect since relay F4 has not been energized. Energization of solenoid-controlled valve V5 bleeds the right end of the cylinder C6. Input is imparted to the left end of cylinder C6 via solenoid-controlled valve V4 which is energized over closed contact Ala. Accordingly, the rail-adjusting cylinder and piston C6 is activated until such time as the contactor TPa, which is ganged to the linkage associated with the guide rail 88, assumes the neutral position illustrated in FIG. 3 whereupon the connection across the energizing contacts of relay A2 is opened and the relay restores to the illustrated position in FIG. 3.

In FIG. 4, there is shown a typical running condition for the apparatus wherein relay R4 has been energized to transfer its contact R4H, R46 such that the relays A1, A2 are placed under direct control of the photocells P1, P2. For the illustrated condition, it -will be noted that fabric is removed from photocell P2 thereby signalling relay A2 to activate the contacts thereof which is effective to establish an energization circuit for solenoid-controlled valve V5 over contacts R417, R4b. Since fabric overlies photocell P1, contact Ala remains closed and solenoid-controlled valve V4 remains energized. For all practical intents and purpose, the rail-actuating piston and cylinder C6 signals that the operation is proceeding properly and that guide track `88 does not have to be ydisplaced (see the condition illustrated in FIG. l wherein photocell P1 is co-vered by the material M while photocell P2 is exposed signalling the proper feed of the particular assembly M to the stitching location). At such time as photocell P1 is exposed to light, indicating that the edge e has gone too far to the left off of the stitching path (when viewed from the right in FIG. l), relay A1 is activated to open contact Ala which energizes solenoid-controlled valve V4 to port the corresponding side of the cylinder C6 to atmosphere, with the other side being connected to air under pressure. This obviously brings about a corresponding restoration of the edge e of the material M to the proper feeding position relative to the needle 24. If the material shifts to far to the right blocking both photocells P1, P2, relay A2 transfers to interrupt the energization circuit for solenoid-controlled valve V5. With the continued application of pressure over solenoid-controlled valve V4 to the opposite side of the cylinder C6, the corresponding correction is imparted to the guide track 88 until such time as the edge is restored to the proper position for stitching.

A typical sequence of operation will now be described in detail to facilitate a more thorough understanding of the present invention:

At the start of the operation, the operator places the material M onto the feed bed of the machine overlying the conveyor and places the leading end of the assembly beneath the presser foot 28. The presser foot is elevated to its inoperative position under control of cylinder C1 and the cutter 46 is along the stitch line having just cut the previous fabric assembly. The operator then adjusts the clam-p assembly 108 along the guide track 88 to a position wherein the clamp pin 120 is engaged with the trailing end of the contoured edge e. Based upon a modest amount of experience, the operator will determine whether or not the lateral position of the guide track 88 should be adjusted relative to the stitchingtlocation by turning knob 106 to assure that the material M will not have to make too radical an excursion as it is fed through the sewing machine 1'6. Thereupon, the operator depresses foot control FSI which actuates relay R2 which in turn deenergizes relay R1. Energization of relay R2 under the moment-ary control of the foot switch FSl completes a holding circuit. Deenergization of relay R1 allows the presser foot 28 to move against the work to clamp the same and retracts the cutter disc 46 from the `stitch path until the end of the machine cycle. Thereupon, the operator depresses foot switch -FSZ which act tivates relay R3. Transfer of contact R3a causes clamp pin 120 to engage the trailing end of the work in response to deenergization of its solenoid SL and to also activate solenoid-controlled valve V3 which engages the clutch associated with the sewing machine motor 30 and activates the clamp-propelling cylinder and piston C4 to overcome the inertia of the system and start the clamp assembly 108 down the guide track 88. The presser foot 24 and rotary puller 46 are eifective to advance the work through the stitching location, with the trailing end thereof being steered under control of the guide rail 88 and the photocell controls P1, P2 as previously described. The closing of foot switch FSZ energizes relay R4 which transfers its contacts to disable the track positioner TP and places the rail-adjusting cylinder and piston C6 under direct control of the photocells P1, P2 for the continuous monitoring of the position of the edge e of the material M, 'as previously described in conjunction with FIG. 4. Periodically, one side or the other of the cylinder C6 is ported to atmosphere, with the other side being connected under pressure to establish new adjusted positions for the guide track 88 as the edge e of the material is constantly monitored in advance of the stitching location. At the end of the run, the clamp assembly 108 contacts the stop switch SS which disrupts the holding circuit for relay R3 -by opening the holding circuit established over contact R315. Transfer of relay R3 to the position illustrated in FIG. 3 disrupts the energization circuit for solenoid-controlled valve V3 which releases the clutch associated with motor 30 and permits the internal spring within the clamp-starting cylinder C4 to restore the same to the illustrated starting position. Also, opening of stop switch SS opens the energization circuit for relay R4 which once again places the system under control of the track positioner TP which simultaneously reestablishes the initial adjusted position for the guide track as set in the irst instance by the adjustment of dial 180. For example, as described in conjunction with FIG. 5, the contactor TPa may be on segment TPa when the end of the stitching interval is signaled by stop switch SS and the deenergization of relay vR4 will thereby bring about the repositioning of the guide track to the requisite starting position. Transfer of Contact Ra of relay R3 against contact R3a energizes the solenoid controlled valve lifting clamp pin 120 and simultaneously sends the clamp assembly 108 back to the adjusted starting position by activation of the Clamp-return cylinder and piston C3.

Although the opening of stop switch SS also disrupts the holding circuit over contact RZb for relay -RZ transferring its contacts to complete the energization circuit for relay R1, the time delay of relay R1 is such that Contact Rla will remain open for a time which, although relatively short, is sufficient to allow the end of the fabric to pass the stitching location. There is suiiicient inertia in the drive of the sewing machine 16 to continue feed via the feed dog thereof and the supplemental rotary puller 46, notwithstanding the release of the clutch 38. As a final step, in response to closing of contact Ria, presser foot 28 is lifted to the elevated position and cutter disc 46 is swung over the trailing threads of the completed assembly to cut such threads.

The sequence is completed runder control of the track positioner TP in response to deener-gization of relay R4 which restores the guide track S8 to the initial adposition whereupon the operator loads the next Piece or fabric assembly into the equipment. At the end of any given production run, it is a relatively simple matter to make the necessary readj-ustments to accommodate the next stitching pattern.

What I claim is:

1. A machine for stitching material along a prescribed stitch line coextensive with and spaced inwardly from an edge thereof comprising a support, sewing mechanisms on said support including a reciprocating needle operable at a stitching location for successively stitching said material along said prescribed stitch line, said material being arranged forwardly of said stitching location and advanced toward and through said stitching location along a normal feed path relative to said needle, guide means engageable with said material and operable to impart steering motion to said material as the same is advanced toward said stitching location for displacing said material from side to side relative to said normal feed path such that said material will be stitched substantially along said stitch line, said guide means including an elongated guide rail projecting forwardly of said needle and a clamp movably mounted on and guided by said rail, means mounting said guide rail on said support for movement relative to said normal feed path, said clamp being engageable with said material contiguous to the trailing end of said edge when the leading end of said edge is initially positioned at said stitching location, means responsive to deviations of said edge relative to said normal feed path for moving said guide rail in a direction to restore said edge, said guide rail being effective in response to its movement to impart steering motion to said clamp as the latter is moved therealong and toward said stitching location to continuously orient and present successive edgeadjacent portions of said material in relation to said sewing mechanisms at said stitching location for stitching along said prescribed stitch line.

2. A machine according to claim 1 including materialadvancing means engageable with said material for transporting the same through and beyond said stitching location.

3. A machine according to claim 1 wherein said elongated guide rail is rigid and including means for pivotally mounting said guide rail on said support.

4. A machine according to claim 1 including control means for moving said rail relative to said normal feed path and having a pair of photocells disposed contiguous to said needle and at opposite sides of said normal feed path for sensing deviations of said edge.

5. A machine according to claim 4 including means responsive to and under control of said photocells for positioning said guide rail to impart the requisite steering motion to said clamp.

6. A machine according to claim 1 including means under control of the machine operator for initiating a stitching interval during which said clamp moves from an adjustable starting position remote from said needle to a finishing position adjacent said needle and means responsive to movement of said clamp to said finishing position for concluding said stitching interval.

7. A machine according to claim 6 wherein said sewing mechanisms including a spring biased presser foot and means for holding said presser foot in an elevated position until the initiation of said stitching interval.

8. A machine according to claim 6 including a cutter positioned behind said needle for severing stitching threads which normally interconnect completed stitched material assemblies.

9. A machine according to claim 6 including means operable in response to the initiation of said stitching interval to propel said clamp along said guide rail out of said adjustable starting position toward said iinishing position.

10. A machine according to claim 6 including means operable at the end of said stitching interval for disengaging said clamp from said material.

11. A machine according to claim 6 including means operable when said material clamp is in said finishing position and after release thereof from said material to propel said clamp back toward said starting position.

12. A guiding mechanism for advancing material to a work location while continuously orienting said material in accordance with the contour of an edge thereof comprising an elongated guide member extending toward said work location, means for mounting said guide member for movement relative to said work location, a follower engaging said guide member and movable therealong and clamp means operatively connected to said follower and engageable with said material such that the latter is guided in response to movement of said follower along Said guide member as the latter moves relative to said work location.

13. A guiding mechanism according to claim 12 including means for moving said follower along said guide member toward said work location.

14. A guiding mechanism according to claim 12 including a conveyor arranged to underlie and engage said material and to advance the same along a feed path toward said work location.

15. A machine for stitching material along a prescribed stitch line comprising sewing mechanisms at a stitching location for successively stitching said material along said prescribed stitch line, said material being arranged forwardly of said stitching location and advanced toward and through said sewing mechanisms along a normal feed path relative thereto, guide means engageable with said material and operable to impart steering motion to said material as the same is advanced toward said sewing mechanisms for displacing said material relative to said normal feed path such that said material will be stitched substantially along said stitch line, said guide means including a cam member and a follower movably mounted on and guided by said cam member, means mounting said cam member for movement relative to said normal feed path, said follower being engageable with said material contiguous to the trailing end of said edge when the leading end of said edge is initially positioned in operative relation to said stitching mechanisms, means responsive to deviations of said edge relative to said normal feed path for moving said cam member in a direction to restore said edge, said cam member being effective in response to its movement to impart steering motion to said follower as the latter is moved therealong and toward said stitching mechanism.

16. A machine according to claim 15 including material-advancing means engageable with said material for transporting the same through and beyond said stitching location.

17. A machine according to claim 15 wherein said cam member is an elongated guide rail and including means for pivotally mounting said guide rail.

18. A machine for stitching material along a prescribed stitch line in relation to an edge thereof comprising a support, sewing mechanisms on said support operable at a stitching location for successively stitching said material along said prescribed stitch line, said material being arranged forwardly of said stitching location and advanced toward and through said stitching location along a normal feed path relative to said needle, mov- Cil able guide means engageable with said material and operable to impart steering motion to said material at the same is advanced toward said stitching location for displacing said material relative to said normal feed path such that said material will be stitched substantially along said stitch line, said guide means being engageable with said material contiguous to the trailing end of said edge when the leading end of said edge is initially positioned at said stitching location, means responsive to deviations of said edge relative to said normal feed path for moving said guide means in a direction to restore said edge, said guide means being effective in response to its movement to impart steering motions to said material as it moves toward said stitching location to continuously orient and properly present successive edge-adjacent portions of said material in relation to said sewing mechanisms.

19. A machine according to claim 18 including means for mounting said guide means for movement in relation to said normal feed path such that said guide means may be adjustable before initiating a stitching interval.

20. A machine according to claim 19 including means operable at the end of said stitching interval for restoring said guide means to the adjusted initial position.

21. A machine according to claim 20 wherein said guide means includes an elongated pivoted guide rail projecting forward of said sewing mechanisms and a clamp movably mounted on and guided by said guide rail and movable toward said stitching location during said stitching interval.

22. A machine according to claim 21 including control means for moving said guide means relative to said normal feed path, said control means including photocells positioned in relation to said normal feed path for sensing devilations of said edge in relation to said normal feed pat 23. A machine according to claim 18 including vacuum means disposed adjacent said normal feed path for positioning said material for operation thereon of said sewing mechanisms.

References Cited UNITED STATES PATENTS 1,646,129 10/ 1927 Wagner. 1,942,128 1/1934 Sommer. 2,290,123 7/ 1942 Wilfong 112-203 2,679,620 5/1954 Berry 1l21024 XR 3,072,081 1/1963 Milligan et al. 3,182,619 5/1965 Sally 112--153 XR JAMES R. BOLER, Primary Examiner.

U.S. Cl. X.R.

Claims

1. A MACHINE FOR STITCHING MATERIAL ALONG A PRESCRIBED STITCH LINE COEXTENSIVE WITH AND SPACED INWARDLY FROM AN EDGE THEREOF COMPRISING A SUPPORT, SEWING MECHANISMS ON SAID SUPPORT INCLUDING A RECIPROCATING NEEDLE OPERABLE AT A STITCHING LOCATION FOR SUCCESSIVELY STITCHING SAID MATERIAL ALONG SAID PRESCRIBED STITCH LINE, SAID MATERIAL BEING ARRANGED FORWARDLY OF SAID STITCHING LOCATION AND ADVANCED TOWARD AND THROUGH SAID STITCHING LOCATION ALONG A NORMAL FEED PATH RELATIVE TO SAID NEEDLE, GUIDE MEANS ENGAGEABLE WITH SAID MATERIAL AND OPERABLE TO IMPART ENGAGEABLE WITH SAID MATERIAL AS THE SAME IS ADVANCED TOWARD SAID STITICHING LOCATION FOR DISPLACING SAID MATERIAL FROM SIDE TO SIDE RELATIVE TO SAID NORMAL FEED PATH SUCH THAT SAID MATERIAL WILL BE STITCHED SUBSTANTIALLY ALONG SAID STITCH LINE, SAID GUIDE MEANS INCLUDING AN ELONGGATED GUIDE RAIL PROJECTING FORWARDLY OF SAID NEEDLE AND A CLAMP MOVABLY MOUNTED ON AND GUIDED BY SAID RAIL, MEANS MOUNTING SAID GUIDE RAIL ON SAID SUPPORT OR MOVEMENT RELATIVE TO SAID NORMAL FEED PATH, SAID CLAMP BEING ENGAGEABLE WITH SAID MATERIAL CONTIGUOUS TO THE TRAILING END OF SAID EDGE WHEN THE LEADING END OF SAID EDGE IS INITIALLY POSITIONED AT SAID STITCHING LOCATIN, MEANS RESPONSIVE TO DEVIATIONS OF SAID EDGE RELATIVE TO SAID NORMAL FEED PATH FOR MOVING SAID GUIDE RAIL IN A DIRECTION TO RESTORE SAID EDGE, SAID GUIDE RAIL BEING EFFECTIVE IN RESPONSE TO ITS MOVEMENT TO IMPART STEERING MOTION TO SAID CLAMP AS THE LATTER IS MOVED THEREALONG AND TOWARD SAID STITCHING LOCATION TO CONTINUOUSLY ORIENT AND PRESENT SUCCESSIVE EDGEADJACENT PORTIONS OF SAID MATERIAL IN RELATION TO SAID SEWING MECHANISMS AT SAID STITCHING LOCATION FOR STITCHING ALONG SAID PRESCRIBED STITCH LINE.