US3358626A - Automatic sewing machine system - Google Patents

Description

Dec. 19, 1967 c. J. BRYAN 3,358,626

AUTOMATIC SEWING MACHINE SYSTEM Filed Oct. 2 Sheets-Sheet l INVENTOR CARNEY J BRYAN Dec. 19, 1967 c. J. BRYAN 3,358,626

AUTOMATIC SEWING MACHINE SYSTEM Filed Oct. 23, 1965 2 Sheets-Sheet 2 INVENTOR CARNEY J BRYAN RNEYS United States Patent 3,358,626 AUTOMATIC SEWING MACHINE SYSTEM Carney J. Bryan, Greensboro, N.C., assignor, by mesne assignments, to Ivanhoe Research Corporation, New York, N.Y., a corporation of Delaware Filed Get. 23, 1965, Ser. No. 502,970 8 Claims. (Cl. 112-2) The present invention relates to a fully automatic sewing machine for stitching fabric work material along any desired predetermined path extending in more than one dimension and having a system for sensing the correct positioning of fabric work material at all times during a complete operating cycle. More particularly, the sensing apparatus continuously detects the proper positioning of the work material in more than one coordinate direction throughout the full cycle to assure that the desired stitching pattern is produced and that the completed work material is properly delivered.

This invention is an improvement in the automatic high-speed stitching methods and apparatus disclosed and claimed in application Ser. No. 436,763, filed on Mar. 3, 1965, and which is assigned to the same assignce as the present invention.

In an automatic sewing machine embodying the system of the present invention the various pieces of the fabric work material are supported upon an electrically conductive work supporting surface upon which they can readily be slid. They are propelled past the stitching station by a clamp member moving in more than one coordinate direction for producing the desired multi-dimensional stitching pattern in the material. This clamp member engages the upper surface of the fabric material by a friction grip which exceeds the friction force between the lower surface of the material and the conductive surface, which is provided by a conductive table top. Thus, during the movement in two coordinate directions the fabric material is driven by the differential in friction existing between the clamp member and the material on one hand and that between the material and table top on the other hand.

There are periods during an operating cycle when the clamp member is in continuous motion in two coordinates and the fabric work material as a. whole is intended accurately to follow this two-coordinate movement throughout a complete cycle of operation. The table has an electrically conductive top surface and electrically conductive sensing means are mounted upon the movable clamp and are resiliently biased down toward the conductive table top. If at any time during an operating cycle the non-conductive work material should accidentally become displaced relative to the clamp member, then electrical contact is established to produce an automatic protective sequence.

It is among the objects of the present invention to provide an automatic sewing machine system which sews the fabric work material along any desired predetermined path in two coordinate directions at high speed while assuring proper positioning of the material during operation.

Advantageously, the present invention enables the stitching operation to start at the edge or at any interior point in an expanse of work material, and the stitching automatically progresses at a high rate of speed along straight lines and around bends and abrupt changes in direction to produce the desired path of stitches extending in two coordinates in a manner suitable for automatically fabricating parts and components of garments and the like in an automation system.

As used herein the term work material is intended to mean fabric, cloth, felt, canvas, leather, sheet or similar fabric-like goods upon which the stitching work is "ice performed. This term is intended to include all such types of goods able to accommodate small amounts of distortion in the plane of the goods themselves, regardless of whether the material of the goods is in one piece or multiple pieces, one layer or multiple layers, regardless of whether the goods are woven, non-woven, felted, in sheet form, porous, perforate or imperforate, natural or synthetic or blended.

The term stitching along a path extending in two dimensions (in two coordinates) is intended to mean that the path of the stitches in the work material can be defined with respect to the general plane of the work material in terms of two coordinates, and regardless of whether the work material itself as a whole is planar or non-planar or is subsequently used in a planar or non-planar form. In other words the stitching path may include straight-line segments, curved segments, angles, abrupt changes in directions, spirals, cusps, and the like.

In this specification and in the accompanying drawings, is described and shown an automatic sewing machine system embodying the present invention, but it is to be understood that this disclosure is not intended to be exhaustive nor limiting of the invention, but on the contrary is given for purposes of illustration in order that others skilled in the art may fully understand the invention and the manner of applying the system in practical use and will understand how to modify and adapt it in various forms, each as may be best suited to the conditions of a particular application.

The various objects, aspects, and advantages of this invention will be more fully understood from a consideration of the following specification in conjunction with the accompanying drawings, in which:

FIGURE 1 is a perspective view of an automatic highspeed two-coordinate sewing machine system embodying the present invention;

FIGURE 2 is a top plan view of the movable work clamp member including the sensing contact elements mounted thereon, and shown on a larger scale than FIG- URE 1;

FIGURE 3 is a partial sectional view taken along the line 33 of FIGURE 2 and shown on enlarged scale;

FIGURE 4 is a partial sectional view taken along the line 44 of FIGURE 2 and showing operation in relationship with the needle; and

FIGURE 5 is a schematic electrical circuit diagram of the control circuit.

In FIGURE 1, is shown an automatic sewing machine system 10, and the work material W which is being stitched is a plurality of layers of fabric to be used in part of a garment. This work W is held by a rapidly movable clamp member 12 which frictionally engages the top surface of the work and serves to slide the work in two coordinate directions over a work table 14. Thus, the work is moved past a reciprocating needle 16 secured in the needle bar 17 of a high-speed sewing machine 18, and this system is capable of producing a line of stitches S along any desired stitching path extending in two coordinate directions.

As shown in FIGURES 2, 3 and 4, the clamp member 12 includes a lightweight rigid frame 20 with a resilient coupling medium 22 attached to the frame and pressing down onto the work W closely adjacent to the line of stitches S. The resilient coupling medium 22 is compliant in compression so as to accommodate different thicknesses in the work material, for example where different numbers of layers are present at different regions of the work. This coupling medium 22 is also compliant in shear to accommodate the arresting of small localized areas of the work W during each instant the needle 16 is inserted in the work while the remainder of the work is in continuous movement at high speed. In this example the coupling medium 22 is sponge rubber.

This automatic sewing machine system is capable of stitching the work material W at a high rate of speed, except that the sewing machine 18 is run at a slower rate for brief instants at the very beginning and at the end of each stitching pattern S. The clamp member 12 is connected to an arm 24 which is driven by drive mechanism generally indicated at 25, as will be described in detail further below.

When the stitching pattern S has been completed, the needle 16 is raised up out of the way and the thread is automatically cut as explained in said copending application Ser. No. 436,763. Then the clamp member 12 is quickly moved to the desired delivery point on the work table 14 and is elevated so as to disengage the resilient coupling medium 22 from the work to release the completed work at that delivery point. While the clamp member 12 is elevated, it is brought into relative position above a new piece of work material at a work receiving point. The clamp member is lowered onto this new work and is quickly moved back into operative relationship with respect to the needle 16. It is noted that the completed work may be delivered to a different point on the work table 14 from that at which the new work is received, or the delivery and receiving locations may be the same, as may be desired in a particular production application.

During the stitching operation the work material W is being slid over the table 14 past the needle 16 which is reciprocated up and down by the needle bar 17. The needle point passes down through a throat opening 26 in the table 14, and the stitches are formed between a top thread 27 carried by an eye in the needle and a lower thread (not shown) supplied from a bobbin mechanism below the table in conventional manner. The localized region of the work material which is briefly penetrated by the needle 16 is arrested in its movement by an annular arrestor foot 28 surrounding the needle. This arrester moves up and down into contact with Work material W in timed relationship with the needle stroke as explained in said copending application. In certain production installations the arrester foot 28 may be omitted, and the needle 16 itself serves to arrest the forward movement of that region of the work material being penetrated by the needle.

The work material W as, a Whole is driven by the differential in friction between the coupling medium 22 and the top surface of the work W on one hand and that between the lower surface of the work and the table 14.

this table top 14 is formed of polished aluminum or stainless steel. It is electrically connected as indicated at 29 to the main chassis 30 (FIG. 1) of the system so that the table top 14 is always held at ground potential. Electrically conductive sensing means 32 are carried by the movable clamp 12 and are positioned to rest upon the very edge region of the work material being stitched. Upon any slight displacement of the work material W relative to the clamp member 12, the sensing means 32 touches the table 14 to complete an electrical circuit, actuating a protective sequence, as will be explained further below. In this illustrative embodiment the sensing means 32 includes a plurality of sensing contact elements mounted upon the clamp frame 20 and insulated therefrom by insulating bushings 34 and spacers 36. Each sensing element 32 has an L-shape including a terminal portion 37 resting upon the spacer 36 and secured by a mounting screw 38 to the bushing 34, which is held in an undercut socket in the frame 20. An intermediate spring portion 39 urges a vertical leg 40 down toward the conductive table top 14. The. lower end of the leg 40 is bent up to form a rounded contact 41 which avoids snagging the work W.

As shown in FIGURE 2, there are sensing openings 42 which are positioned immediately adjacent to spaced points along a plurality of the difierent edges 44, 45, 46 and 47 of the work material W. The vertical legs 40 extend down through these openings 42 so that the contacts 41 rest upon the very edge region of the material adjacent to these edges 44-47. It is to be noted that the respective edges 44-47 face in substantially different directions, so that any slight displacement of the work material W in any direction relative to the clamp member 20 will permit one or more of the non-snagging contacts 41 to slide ofi of the respective edge and to spring down against the table 14. This completes a control circuit as will be explained in connection with FIG- URE 5 so as to stop the system.

In the illustrative example the stitching pattern S extends along adjacent to the edge 46, and in order to assure that this edge 46 remains properly positioned, the clamp frame 20 has a branch 48 extending along beside the edge 46 and connected by a back portion 49 to the main body of the clamp frame 20. Two of these contacts 32 are mounted on this branch 48 so that they can engage the edge region 46 while providing clearance for the line of stitches S, as seen in FIGURE 4. The stitching path progresses along an open channel 50 between the branch 48 and the main body of the clamp frame 20, and the resilient coupling medium 22 presses down against the work W near to the intended line of stitches.

The terminals 37 are connected by insulated leads 52 to a control wire 54 which is mounted on the arm 24 extending along the arm past a fixed pivot point 56 in the drive mechanism 25 and connected into a control circuit 58.

As shown in FIGURE 1 the arm 24 is driven by a pair of lightweight triangular cam follower levers 64 and 65 driven by a pair of cams 66 and 67 mounted on a common vertical shaft 70. The levers 64 and 65 are disposed on generally opposite sides of the cams 66 and 67 and are arranged and connected so that the lever 64 produces mainly movement of the arm 24 in a direction parallel to its own length while the other lever 65 mainly produces angular movement of the arm 24 about a pivot 71. The lever 64 has the fixed pivot 56 and a follower roller 73, so that it produces velocity multiplication at the pivot connection 71 with the arm. Consequently, the arm 42 is moved in a direction along its length at a higher rate of speed than that imparted by the cam 66 to the roller 73.

The other lever 65 has a cam follower roller 74, a pivot connection 75 to a cross link 76, and an intermediate fixed pivot 77. Thus, it has approximately equal lever arms to provide a velocity at the pivot connection 75 which is approximately equal to that imparted by the cam 67 to the roller 74. This velocity is transferred by the cross link 76 to a pivot connection 78 on the arm 24. With this arrangement there is a movement of the end of the arm 24 perpendicular to its length which is at a higher rate of speed than that imparted by the cam 67 to the roller 74. Advantageously, this arrangement produces velocity multiplication with respect to both coordinates of motion that are substantially equal. Consequently, the cams 66 and 67 may be of substantially the same over-all size for a wide variety of stitching patterns, thus minimizing the over-all sizes and masses of the levers, link 76 and arm 24 while enabling large pattern areas to be sewn at high speed.

The arm 24 is hollow and is tapered down toward both ends and has a maximum width near the pivot connection 78 to resist bending stress where the lateral thrusts are imparted. The triangular levers 64 and 65 are hollow, and the cross link 76 is tubular to provide maximum rigidity to mass ratio.

In order to hold the follower rollers 73 and 74 against their respective cams, spring forces of substantially constant magnitude and directed inwardly generally toward the shaft 70 are applied to each lever at a point adjacent to the follower roller. For example, in this apparatus shown these forces are provided by strip springs 80 and 81 of the type which are self-winding on drums to generate a generally constant tension force regardless of extension, available commercially.

To prevent the cam movement from being influenced by the forces of the follower rollers 73 and 74 bearing against them and thus reacting against back lash in the drive gearing, suitable braking means are provided. For example, there is a large diameter disk caliper brake 82 providing a constant drag force upon a disc 83 on the shaft 70 so that any back lash present is always taken up in the same direction with respect to the rotation of the shaft 70.

To provide downward force on the clamp member 12 with a minimum of mass effect on the arm 24 there is a strip spring 84, which is similar to the springs 80 and 81 discussed previously. This tension spring 84 is secured to a long, substantially vertical cable which is connected to the underside of the arm 24 so as to pull downwardly on this arm with relatively constant force regardless of the horizontal position of the arm.

When the stitching of the pattern is completed, then the clamp member 12 is moved to a predetermined delivery position at which the arm 24 is raised against the force of the spring 84, thus releasing the completed work from engagement with the resilient compliant means 22. For raising the arm 24, lift means 85 are provided which engage the arm in the delivery position. After the completed work has been removed a new piece of work can be placed beneath the clamp member 12 or, alternatively, the clamp may be moved to another position at which it can be raised by another lift mechanism similar to the lift means 85.

The driving power for the system is provided by a main drive motor 90 connected to a counter shaft 91, and a main shaft 92 parallels this counter shaft. The main shaft 92 can be driven from the shaft 91 through a highspeed clutch 93 and a timing belt 94. This is a magnetic clutch 93, and when it is actuated the sewing machine 18 sews at a high rate of speed. For operation at an intermediate speed if desired, a timing belt 95 is connected to an intermediate speed magnetic clutch 96. For providing a slow operating speed, both of the clutches 93 and 96 are disengaged, and the driving power is supplied from a drive motor and speed reducer 97 through a slowspeed clutch 98.

The rotation of the main shaft 92 bears a known speed relationship with respect to the rotation of the cam shaft 70, the drive path extending through a coupling 99, a speed-reduction gear mechanism 100, and a change gear train 101, 102 to a driven gear 103 on the shaft 70. To change the speed relationship between the rotation of the main shaft 92 and the cam shaft 70, the gears in the train 102 are changed.

The cams 66 and 67 are individually removably secured to the shaft 70 at a fixed angular orientation. To change the sewing pattern for stitching difierent pieces of work material, these cams are replaced by other cams. Also, the clamp member 12 is removed from the arm 24 by disconnecting bolts 104 and is replaced by a different clamp member having a shape corresponding with the desired stitching pattern. The control wire 54 includes a disconnect plug 106 for attaching the leads 52 from the sensing elements on the clamp member.

In order to drive the sewing machine 18 at a known relationship with respect to the cam shaft 70, a drive path is provided from the main shaft 92 to a driven sheave 108 on the crank shaft 109 of the sewing machine. This drive path including a timing belt 110, a drive disengage and needle raise and lock-up mechanism 112 and a timing belt 113.

As shown in FIGURE 5, the control wire 54 is connected to a relay winding 114 to be energized by the lowvoltage secondary 116 of a step-down transformer 117 having its primary 118 connected across the alternating current supply lines 119 and 120, which supply A.C. at suitable voltage, for example 120 volts, 60 cycles. If the work W becomes displaced, then one or more of the contacts 41 touches the table 14 to complete a circuit through the secondary 116 back to the ground connection 29, thus energizing the relay winding 114 to open normally-closed relay contacts 122 and to close normally-open relay contacts 123. Closure of the contacts 123 completes a circuit from the line 119 through a lead 124, through contacts 123, to an alarm signal 125 and through a lead 126 to an electromagnetic brake 127 (see also FIGURE 1), which immediately stops the main shaft 92. The operator is alerted by the alarm 125 and can reposition or remove the work W by lifting the arm 24 against the force of the spring 84.

During normal operation the contacts 123 are open, and the brake 127 is operated by a circuit extending from the line 119 through a lead 128 and through control means 130 connected to the brake 127. Also, during normal operation the contacts 122 are closed, and the respective clutches 93, 96 and 98 are operated by control means 131, 132 and 133. These control means 130-133 include switches and relays which are actuated in accordance with the position of the cams 66 and 67 to produce the desired cycle of operation of the sewing machine 18.

It will be appreciated that this automatic system is intended to handle work materials having non-conductive or high insulating characteristics so as to maintain the relay winding 114 deenergized so long as all of the contacts 41 are resting upon the work W. If the work material W includes any conductive filaments or layers, such as wire strands or wire gauze, then it is still possible to utilize this system provided that the work material has a sandwich construction such that one or more layers is of insulating material. The criteria to observe are that the contacts 41 remain insulated from the table 14 when they rest on the work W. To prevent inadvertent actuation of the system in the case of work material containing conductive filaments or layers, it may be desirable to insulate the needle from the common return circuit. The reason for insulating the needle in such a case is that upon penetration of the work it may touch the conductive strands or layers which may also be touching one of the contacts 41.

From the foregoing it will be understood that the automatic sewing machine system of the present invention is well suited to provide several advantages in operation. It will be appreciated from this description that various possible embodiments may be made of the various features of this invention and the apparatus herein described may be varied in different parts, all without departing from the scope of the invention, and that all matter hereinbefore set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense, and that, in certain instances, some of the features of the invention may be used without a corresponding use of other features, all without departing from the scope of the invention as defined by the following claims.

What is claimed is:

1. A sewing machine system for automatically sewing fabric Work material along a stitching path extending in two dimensions comprising a sewing machine having needle means operating at a stitching station, a work table surrounding said stitching station and having an electrically conductive top surface upon which the work material is slidable, a movable clamp member engageable down upon the fabric work material, drive means for moving said clamp member, control means for said drive means, electrical contact sensing means extending down from said clamp member positioned to rest upon the edge regions of fabric work material properly positioned beneath the clamp member, and circuit means interconnecting said contact sensing means, said control means and said conductive top surface for stopping said drive means if the fabric workpiece shifts its position with respect to the clamp member to permit said sensing means to touch said conductive top surface.

2. An automatic sewing machine system comprising a. sewing machine including needle means for stitching fabric workpieces, a work table having a smooth top surface for supporting the fabric workpieces, said top surface being electrically conductive and providing low friction for fabric workpieces being slid thereover, automatic drive means, movable arm means driven by said drive means, said arm means having a clamp means providing high friction for gripping and sliding the workpieces over said table surface relative to said needle means to stitch the workpiece, a plurality of sensing contacts mounted on said clamp means and being resiliently biased toward said conductive table surface, said sensing contacts being normally insulated from said conductive top surface by a fabric workpiece properly positioned beneath said clamp means, control means for controlling said drive means, and circuit means interconnecting said control means and said conductive table surface and said sensing contacts.

3. A sewing machine system for automatically sewing fabric work material along a stitching path extending in two dimensions comprising a sewing machine having needle means operating at a stitching station, a work table surrounding said stitching station and having an electrically conductive top surface upon which the work material is slidable, a movable arm, a clamp member carried by said arm and engageable down upon the fabric work material, drive means for moving said arm, control means for said drive means, said control means being connected to said table top, electrical contact sensing means extending down from said clamp member in positions to rest upon the edge regions of fabric work material properly positioned beneath the clamp member, and an electrical circuit extending from said control means along said arm to said contact sensing means for stopping said drive means if the fabric workpiece shifts its position with respect to the clamp member to perirnt said contact sensing means to touch said conductive top surface.

4. An automatic sewing machine system comprising a sewing machine including needle means for stitching fabric workpieces, a work table having a smooth top surface for supporting the fabric workpieces and upon which the workpieces are slidable, said top surface being electrically conductive, automatic drive means, movable arm means driven by said drive means, said arm means having a clamp frame, a resilient coupling medium secured to the bottom of said clamp frame providing high friction for gripping and sliding the workpieces over said table surface relative to said needle means to stitch the workpiece, a plurality of sensing elements mounted on said clamp frame and being insulated therefrom, said sensing elements having rounded contact ends extending down below said resilient coupling medium and being resiliently biased toward said conductive table surface, said contact ends being normally insulated from said conductive top surface by a fabric workpiece properly positioned beneath said resilient coupling medium, control means for controlling said drive means, and circuit means interconnecting said control means and said conductive table surface and said sensing elements.

5. A sewing machine system for automatically'sewing fabric work material along a stitching path extending in two dimensions comprising a sewing machine having needle means operating at a stitching station, a work table surrounding said stitching station and having an electrically conductive top surface upon which'the work material is slidable, a movable clamp member having a resilient medium secured thereto and providing a firm frictional grip upon the fabric work material when said resilient medium is engaged down upon the Work material,

drive means for moving said clamp member, control means for said drive means, said clamp member having an open channel therein along which an edge of the work material is stitched, a sensing element mounted upon said clamp member and having a contact extending down in a position to engage the work material immediately adjacent to said edge when the work material is properly positioned beneath said resilient medium, said contact being resiliently urged down toward the edge of the work material, and electrical circuit means interconnecting said contact, said control means and said conductive table surface for stopping said drive means if the fabric workpiece shifts its position with respect to the clamp member to permit said contact to touch said conductive top surface.

6. A sewing machine sysem for stitching fabric work material along a stitching pattern extending in more than one dimension comprising needle means operating at a stitching station, an electrically conductive work supporting surface adjacent to said stitching station, said conductive surface enabling the work material to be slid thereon, movable clamp means engageable with the work material for holding the work material against said surface, drive means for moving said clamp means in more than one direction relative to said stitching station for moving the work material to produce the stitching pattern, electrical contact means mounted on said clamp means and springbiased toward said conductive surface, said contact means being positioned to engage an edge region of the work material when the work material is properly positioned with respect to said clamp means, and control circuit means interconnecting said contact means with said drive means and said conductive surface.

7. A sewing machine system as claimed in claim 6 and wherein said contact means are positioned to engage the edge region of the work material at a plurality of locations spaced about the perimeter of the work material.

8. A sewing machine system as claimed in claim 6 and wherein said clamp means has a first portion and a branch portion extending along beside said first portion providing a stitching channel through which said needle means can stitch the work material along a path extending between said branch portion and said first portion, and said contact means includes a contact element mounted upon said branch portion, spring biased toward said conductive surface and positioned to engage an edge region of the work material immediately adjacent to said stitching channel and said contact means includes another contact element mounted upon said first portion, spring biased toward said conductive surface and positioned to engage an edge region of the work material remote from said channel.

References Cited UNITED STATES PATENTS 2,290,123 7/ 1942 Wilfong.

2,483,138 9/1949 Helmer 1l22l9 2,845,885 8/1958 Scarrone ll2203 X 3,013,513 12/1961 Judleson 112203 3,072,081 l/1963 Milligan et al 1l22 3,170,423 2/1965 Henebry 1122 3,204,590 9/1965 Rockerath et al. 1l2203 X PATRICK D. LAWSON, Primary Examiner.

J. R. BOLER, Assistant Examiner,

Claims (1)

1. A SEWING MACHINE SYSTEM FOR AUTOMATICALLY SEWING FABRIC WORK MATERIAL ALONG A STITCHING PATH EXTENDING IN TWO DIMENSIONS COMPRISING A SEWING MACHINE HAVING NEEDLE MEANS OPERATING AT A STITCHING STATION, A WORK TABLE SURROUNDING SAID STITCHING STATION AND HAVING AN ELECTRICALLY CONDUCTIVE TOP SURFACE UPON WHICH THE WORK MATERIAL IS SLIDABLE, A MOVABLE CLAMP MEMBER ENGAGEABLE DOWN UPON THE FABRIC WORK MATERIAL, DRIVE MEANS FOR MOVING SAID CLAMP MEMBER, CONTROL MEANS FOR SAID DRIVE MEANS, ELECTRICAL CONTACT SENSING MEANS EXTENDING DOWN FROM SAID CLAMP MEMBER POSITIONED TO REST UPON THE EDGE REGIONS OF FABRIC WORK MATERIAL PROPERLY POSITIONED BENEATH THE CLAMP MEMBER, AND CIRCUIT MEANS INTERCONNECTING SAID CONTACT SENSING MEANS, SAID CONTROL MEANS AND SAID CONDUCTIVE TOP SURFACE FOR STOPPING SAID DRIVE MEANS IF THE FABRIC WORKPIECE SHIFTS ITS POSITION WITH RESPECT TO THE CLAMP MEMBER TO PERMIT SAID SENSING MEANS TO TOUCH SAID CONDUCTIVE TOP SURFACE.

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