US3754520A

US3754520A - Material stitching apparatus

Info

Publication number: US3754520A
Application number: US00192668A
Authority: US
Inventors: Bennison M Newstead
Original assignee: Individual
Current assignee: W J Clarkson Ltd; Automated Machinery Systems Inc
Priority date: 1970-10-29
Filing date: 1971-10-26
Publication date: 1973-08-28
Anticipated expiration: 1990-08-28
Also published as: DE2154035C2; DE2154035A1; IT940065B; JPS545338B1; GB1371061A

Abstract

Apparatus for facilitating the stitching together of layers of material comprising in combination a sewing machine, the sewing machine including a presser foot, a needle, a drive mechanism for the needle, a control mechanism for starting and stopping the drive mechanism, and a guide; a template, the template comprising a lower plate having a continuous guide track engageable by the guide, first and second top plates, an element pivotally mounting the first and second top plates to the lower plate to be closable over a respective part of the lower plate to hold material to be stitched, the guide track having first starting and finishing points for a stitching operation on material held by the first top plate and second starting and finishing points for a stitching operation on material held by the second top plate, the first and second finishing points being spaced respectively from the second and first starting points, and first operating elements on the template at each of the finishing points; and another drive mechanism for driving the template from the sewing machine so that the guide track follows the guide until one of the operating elements operates the control mechanism to stop the drive mechanism with the needle of the sewing machine at the respective one of the finishing points.

Description

United States Patent [191 Bennison MATERIAL STITCHING APPARATUS [75] Inventor: Michael Newstead Dennison,

Leeds, England [73] Assignee: W. J. Ciarkson Limited, Yorkshire,

England [22] Filed: Oct. 26, 1971 [21] Appl. No.: 192,668

[30] Foreign Application Priority Data Oct. 29, 1970 Great Britain 51,443/70 [52] us. c1. 112/121.12 511 111:. C1. nosb 21/00 58 Field oiSearch 112/121.11, 121.12, 112/121.13, 121.15, 207

[56] References Cited UNITED STATES PATENTS 3,172,379 3/1965 Light ll2/l2l.l2 3,170,423 2/1965 l-lenebry 1 12/l21.12

FOREIGN PATENTS 0R APPLICATIONS 181,490 4/1966 U.S.S.R l12/121.12 175,445 7/1953 Austria ll2/12l.15

ifrjmary Examiner-Werner H. Schroeder v Attorney-Richard K. Stevens, Davidson C. Miller et al.

[ Aug. 28, 1973 [57] ABSTRACT Apparatus for facilitating the stitching together of layers of material comprising in combination a sewing machine, the sewing machine including a presser foot, a needle, a drive mechanism for the needle, a control mechanism for starting and stopping the drive mechanism, and a guide; a template, the template comprising a lower plate having a continuous guide track engageable by the guide, first and second top plates, an element pivotally mounting the first and second top plates to the lower plate to be closable over a respective part of the lower plate to hold material to be stitched, the guide track having first starting and finishing points for a stitching operation on material held by the first top plate and second starting and finishing points for a stitching operation on material held by the second top plate, the first and second finishing points being spaced respectively from the second and first starting points, and first operating elements on the template at each of the finishing points; and another drive mechanism for driving the template from the sewing machine so that the guide track follows the guide until one of the operating elements operates the control mechanism to stop the drive mechanism with the needle of the sewing machine at the respective one of the finishing points.

10 Claims, 3 Drawing Figures memwwcze um SHEET 1 OF 3 PATENTEDmcea I975 SHEET 2 [IF 3 MATERIAL STITCHING APPARATUS This invention relates to apparatus for facilitating the stitching together of layers of material.

ln the manufacture of some articles, particularly parts of garments, certain operations involve the stitching together of at least two layers of material along a desired stitching line. It is known to hold the layers of material in superposed relationship on a template having a guide track engageable with a guide element on a sewing machine. The arrangement is such that by moving the template so that the guide track moves about the guide element the layers of material are moved beneath the needle of the machine which passes through material exposed in the guide track so that the material is stitched together along the desired line.

In stitching articles such as'patch pockets the stitching path to be followed is not a closed path, but terminates at two spaced points. Accordingly, after one stitching operation, the direction of movement of a template needs to be changed to return it to its original starting position. If the template is mechanically driven this calls for a reversible drive, or for a disengageable drive so that the template may be returned by hand. Stitching may or may not be possible on the return run, and the arrangement is recognised as being timewasting.

To overcome this it is known to use a double template having two halves, each of which may be operated independently to hold layers of material to be stitched together. The starting point for the stitching operation on material in one half of the template is adjacent to the finishing point for the stitching operation on material in the other half of the template. The template thus calls for drive in a single direction only, and no reverse cycling ofthe template is necessary. However, the two sets of workpieces are stitched together at the adjacent starting and finishing points, and this is disadvantageous as it results in loading and unloading difficulties and a separate cutting operation.

According to the present invention a template for facilitating the stitching together of layers of material comprises a lower plate having a continuous guide track engageable by guide means when in association with a sewing machine, two top plates each pivoted to the lower plate and each closable over a respective part of the lower plate to hold material to be stitched, the

guide track having starting and finishing points for a stitching operation on material held by each top plate, the finishing point associated with one top plate being spaced from the starting point associated with the other top plate, and first operating means on the template at each finishing point for controlling an associated sewing machine to stop the sewing machine at the respective finishing point.

This automatic stopping of the machine at each fin ishing point allows a needle positioning and thread trim operation to be performed so releasing the already stitched pieces of material and making the machine ready for stitching the pieces of material held in the other part of the template.

The means at each finishing point of the template may take any one of a number of forms. Preferably the means is a rampadjacent to the respective finishing point and raised above-part of the upper surface of the lower plate, engageable by the presser foot of the machine tolift the pressure foot, the machine incorporating a microswitch or other switch responsive to this lifting movementto stop the machine. Alternatively, other forms of an operating member may be provided on the template for directly engaging microswitches mounted on the bed or other part of the machine. In a further-alternative the means may be a light transmitting or light reflecting part of the template operating a photocell at;

rangement mounted on the machine. Other arrangements are also possible.

When stitching pocket flaps and other articles it is desirable either to back stitch or to stitch at a higher density at the endparts of the stitching line. To allow for this, the template preferably, has second operating means cooperating with control means on the machine to cause the machine to stitch at a higher density within a selected distance before the finishing point of each stitching line, and preferably also third operating means to cause the machine to stitch at a higher density within a selected distance after the starting point of each stitching line. Again ramps operating on the pressure foot are preferred, but other microswitch operating, photocell or other means may be used.

The invention also includes apparatus for facilitating the stitching togetherof layers of material comprising in combination a sewing machine having a drive mechanism, control means for starting and stoppping said drive mechanism, and a guide means; a template comprising a lower plate having a continuous guide track engaged by said guide means, two top plates each pivoted to the lower plate and each closable over a respec-v tive'part of the lower plate to hold material to be stitched, the guide track having starting and finishing points for a stitching operation on material held by each top plate, the finishing point associated with one top plate being spaced from the starting point associated with the other top plate, and first'operating means on the template at each finishing point; and drive means for driving the template from the sewing ma chine so that the guide track follows the guide means until one of the operating means operates the control means to stop the sewing machine at the respective one of the finishing points.

The means for driving the template conveniently comprises a member pivotally mounted on the bed of the sewing machine, a roller rotatably mounted on the member and capable of frictionally engaging an edge of the template, means for biasing the roller towards the edge of the template, and means for driving the roller from the sewing machine drive in a given direction of rotation. I

The drive from the sewing machine to the rollerdesirably includes a one-way sprag-type clutch driven by an oscillating member from the rocket shaft of the sewing machine. The clutch converts the oscillatory movement into a unidirectional intermittent rotation of the roller, synchronized with the action of the needle of the sewing machine. The roller movement is transmitted to the template to move this intermittently, the synchroni zation ensuring that the template only moves when the needle is out of the material held by the template and is stationary when the needle is in the material.

Although a roller is preferred as the final element of this drive it is possible to use a pinion engaging teeth formed on the edge of the template.

This drive is used while stitching is being carried out, and preferably separate drive means are provided for moving the template from one finishing position to the subsequent starting position. This separate drive means may conveniently comprise a pawl engageable with the roller when moving in said given direction for rotation, and slipping over the roller when moving in the opposite direction, and means for moving the pawl in an arcuate path about the axis of rotation of the roller. The pawl may be carried on any arm pivotally mounted about the axis of rotation and drivableby a pneumatic ram.

The invention may be used in conjunction with a pure sewing machine, or with the type of machine that, as well as stitching, simultaneously cuts the material being worked along a line complementary to and outside the stitching line.

A particular embodiment of the invention will now be described in more detail, by way of example only, with reference to the accompanying drawings in which:

FIG. 1 is a schematic exploded view of parts of a sewing machine modified in accordance with the invention.

FIG. 2 is a plan view of part of the apparatus; and

FIG. 3 is a cross-section on the line Ill-Ill of FIG. 2 with some parts omitted for clarity.

The apparatus includes a template 1 having a lower plate 2 formed with a continuous guide track 3 engaging a part cylindrical guide member 3a secured to the throat or needle plate of the machine and having a hole and a slot therein for receiving respectively a needle and a knife. Two top plates 4 and S are hinged to the lower plate by hinges 6 and 7 respectively, and a tension spring 8 between the top plates biases these to an open position raised from thelower plate 2. The template may have interposed plates with complementary openings or recesses in the top plates to provide a fulling action on at least the upper layer of material placed in the template. The template is divided into two distinct stitching areas, one extending round the outer edge of top plate 4 from point 9 to point 10, and the other extending round the outer edge of top plate from point 11 to point 12. The starting points 9 and 11 of the two tracks are each spaced from the

finishing point

12 or 10 respectively of the other track. Adjacent to each starting point 9 and 11, the upper surface of the lower template carries a single step cam block 13 and 14 respectively. Adjacent to each

finishing point

10 and 12, the upper surface of the lower template carries a two step cam block 15 and 16 respectively.

The outer edge 17 of the template is received in a V- shaped slot 18 formed in the edge of a roller 19 rotatably mounted at the end of one arm of a lever 20 pivoted at 21 to the bed of the machine, the pivot including roller bearings 22 to ensure low frictional resistance to pivotal movement. The other arm 23 of the lever 20 has one end of a tension spring 24 anchored thereto, the other end of the spring being anchored at 25 to the bed. The spring biases the lever counterclockwise about its pivot to press the roller 19 into engagement with the edge 17 of the template and so wedge the edge of the template into the slot 18.

The roller 19 is driven in a clockwise direction as seen in FIG. 2, from the conventional rocker shaft of the sewing machine. A vertical arm secured to the rocker shaft is also pivotally secured to one end of a horizontal arm 26 which is thus driven from the rocker shaft to oscillate in the direction shown by the double ended arrow. The other end of the arm 26 is pivoted at 27 to a drive input member 28 of a one-way spray-type clutch 29, the output member 30 of which is connected to rotate the roller 19. The clutch is of a known type and acts so that as the input member 28 is driven clockwise by the arm 26 the output member 30 and thus the roller 19 are also driven clockwise, but when the input member is driven anti-clockwise this free wheels relative to the output member so that the roller 19 remains stationary.

It will thus be seen that the intermittent rotation of the roller 19 from the sewing-machine drive, gives a positive, intermittent driving movement to the template to drive this so that the track 3 follows the guide member 3a. This movement will be synchronized to the machine needle movement so that the template is stationary when the needle is in material held by the template and is moving when the needle is raised out of the material. The material exposed in the track 3 of the template is thus stitched by the needle as the template is driven by roller. 19.

While either of the distinct stitching areas of the template is being driven past the needle, material exposed in the guide track is being stitched at the stitch density set on the sewing machine, and the material is being cut outside the stitching line. Towards the end point 12 of the stitching line the presser foot of the machine, which has been riding on the surface of the top plate 5, encounters the first section 51 of the two step cam block 16. This partly lifts the presser foot, and this lifting movement is transmitted by a linkage 52 to a lever 53 pivotally mounted at 54 to a fixed part of the machine bed. The free end of the lever 53 carries an operating member 55 which, when the presser foot is so lifted, operates a microswitch 56 to control a solenoid operated pneumatic valve 57. The valve then admits air under pressure to a cylinder 58 to move a piston in the cylinder so that a piston rod 59 moves the usual stitch density control lever 60 of the machine to a higher stitch density setting. Thus, engagement of the section 51 with the presser foot initiates higher density stitchmg.

Further movement of the template then causes the presser foot to ride on to the second section 61 of the two step cam block 16. This further lifts the presser foot, and the operating member 55 is then moved to operate a further microswitch 62. This controls operation of a solenoid operated pneumatic valve 63, to allow fluid to flow to cylinder 63a the piston end of which moves a lever 64 about a fixed pivot 65 to move the control pin 66 associated with the machine motor 67. Movement of the control pin stops the motor 67, so that both stitching and driving of the template cease, and then actuates the needle position and thread trim systems which are conventionally build into industrial sewing machines. The needle is thus lifted from the workpiece and the thread is cut so releasing the stitched material from the machine. The raising of the presser foot allows the top plate 5 of the template to be lifted by the spring 8 so that the stitched material may be removed from the template. The top plate 4 of the template is also in a raised position so that further material to be stitched can be placed beneath top plate 4.

When this has been done a separate control, which may conveniently be a foot-operated pneumatic valve 68, is operated. This admits air under pressure to a cylinder 69, the piston rod 70 of which pulls lever 53 further downwardly and so raises the presser foot 50 fully clear of the template. Microswitches 56 and 62 remain operated, so that the motor 67 is stopped. Operation of the valve 68 also applies air to a cylinder 71, the piston rod of which lifts the knife trimmer so that the knife 71a is raised to a position raised clear of the template.

Operation of the valve 68 is also effective to cause the template to be driven from the finishing position 12 to the subsequent starting position 9. To this end, and referring more particularly to FIG. 2, the valve admits compressed air to a cylinder 72 to extend a piston rod 73 from the cylinder. The piston rod 73 is pivoted at 74 to one end of an arm 75, the other end of which is pivoted at 76 to a lever 77 rotatably mounted about the axis of rotation of the roller 19. The lever 77 carries a from the finishing position 12 to the next starting position 9.

The apparatus is then ready for a further stitching operation. To initiate this the foot is withdrawn from'the valve 68 to allow this to resume its position. A spring 79 then returns the lever 77 and associated parts to their original position, the pawl 78 riding freely over the knurled edge of the roller 19. Springs also return the knife trimmer to the knife lowered position, and the presser foot 50 to its lowered position to contact the single step cam block 13. The operating member 55 clears microswitch 62 so that the control pin is moved to the drive position and the motor thus starts the template driving and the stitching operations. The single step cam block 13 holds the presser foot partially lifted so that microswitch 56 is operated and the stitch density control lever is held in its higher density position to give high density stitching over the first partof the stitching line. When the template has been movedsufficiently for the presser foot to ride off the block 13, the foot is in its fully lowered position and microswitch 56 is released so that the stitch control lever is returned to its normal setting and stitching at normal density takes place until the presser foot engages the first part of the two-part cam block 15 at the end of this stitching path. The sequence described then resurs at the other end of the stitching pathv under the control of cam blocks 15 and 14.

It will be appreciated that the apparatus is not limited to the particular drive system shown, nor to the particular lever and spring system for biasing the roller into engagement with the template. Although a knurled roller is preferred, a smooth one may be used, perhaps in conjunction with a knurled edge template, and it is also possible for both the roller and the template to be toothed. The guide means on the sewing machine need not be on, the needle plate but could, for example, be a roller on the presser foot engaging a guide track in the upper one of the templates.

Means other than the cam blocks 13 to 16 may be used for controlling the machine. For example, the machine may have photoelectric apparatus responsive to light transmitting or light reflecting parts of the template. The particular elements for controlling the stitch density, drive, needle positioning, knife trimming and thread trimming functions of the machine may be varied. The arrangement for. moving the template from one finishing position to the subsequent starting position may also take any one of a number of forms and is not limited to the pawl arrangement described,

I claim:

1. Apparatus for facilitating the stitching together of layers of material comprising in combination a sewing machine and a template; said sewing machine including a fixed bed; guide means on said fixed bed; a presser foot which rides on a surface of said template; a needle; a needle drive mechanism; a template drive mechanism comprising a member pivotally mounted on said fixed bed, a roller rotatably mounted on said member, means, connected to said needle drive mechanism, for driving said roller, and means, connected to said member, for biasing said roller to a position frictionally engaging an edge of said template; a control means .responsive to the position of said presser foot for starting and stopping said needle drive mechanism and said template drive mechanism; and said template comprising a lower plate, first and second top plates, means for pivotally mounting said first and second top plates to said lower plate, said first and second top plates being closable each over a respective part of said lower plate to hold material to be stitched, a continuous guide track formed in said lower plate and engaged by said guide means, said guide track having first starting and finishing points for a stitching operation on material held by said first top plate and second starting and finishing points for a stitching operation on material held by said second top plate, said first and second finishing points being spaced respectively from said second and first starting points; and a plurality of first operating means, on said template at each of said finishing points, for engaging with said presser foot to operate said needle and template drive mechanisms when said engagement occurs.

2. Apparatus as claimed in claim 1 wherein said control means is responsive to the raising of said presser foot above a predetermined height relative to said fixed bed to stop said drive mechanisms, said presser foot rests on an upper surface of said lower plate while stitching is in progress, and each of said first operating means is a ramp adjacent the respective one of said finishing points, said presser foot being engaged with each said ramp to be raised above said predetermined height.

3. Apparatus as claimed in claim 1 wherein said sewing machine further comprises a stitch density control means responsive to the position of said presser foot for controlling the stitching density, and said template further comprises a plurality of second operating means, in advance of said first operating means, for engaging with said presser foot to operate said stitch density control means to increase the stitch density for a time prior to stopping of said needle and template drive mechanisms.

4. Apparatus as claimed in claim 3 wherein said template further comprises a plurality of third operating means, in the region of each of said starting points, for engaging with said presser foot to operate said stitch density control means to increase the stitch density for a time after commencement of stitching.

5. Apparatus as claimed in claim 4 wherein said control means is responsive to the raising of said presser foot above a predetermined height relative to said fixed bed to stop said needle and template drive mechanisms, said stitch density control increases stitch density on raising said presser foot to an intermediate height below said predetermined height, said presser foot rests on an upper surface of said lower plate while stitching is in progress, each of said first operating means is a ramp adjacent the respective one of said finishing points, said presser foot being engaged with each said ramp to be raised above said predetermined height, and each of said second and third operating means is a further ramp adjacent said respective starting and finishing points on to which further ramps said presser foot runs to be raised to said intermediate height.

6. Apparatus according to claim in which said first and second operating ramps are contiguous, with said first operating ramp following and being higher than said second operating ramp.

7. Apparatus according to claim 1 in which said sewing machine further includes a rocker shaft and said means for driving said roller includes an oscillating member converted to said rocker shaft, and a one-way sprag-type clutch driven by said oscillating member.

8. Apparatus according to claim 1 in which separate drive means are provided for moving said template from said first finishing position to said second starting position, and from said second finishing position to said first starting position.

9. Apparatus according to claim 8 in which said separate drive means comprises a pawl engaged with said roller when moving in a given direction of rotation, and slipping over said roller when moving in the opposite direction, and means for moving said pawl in an arcuate path about an axis of rotation of said roller.

10. Apparatus according to claim 9 in which said separate drive means includes a pneumatic ram and said pawl is carried on an arm pivotally mounted about said axis of rotation and drivable by said pneumatic ram.

Claims

1. Apparatus for facilitating the stitching together of layers of material comprising in combination a sewing machine and a template; said sewing machine including a fixed bed; guide means on said fixed bed; a presser foot which rides on a surface of said template; a needle; a needle drive mechanism; a template drive mechanism comprising a member pivotally mounted on said fixed bed, a roller rotatably mounted on said member, means, connected to said neeDle drive mechanism, for driving said roller, and means, connected to said member, for biasing said roller to a position frictionally engaging an edge of said template; a control means responsive to the position of said presser foot for starting and stopping said needle drive mechanism and said template drive mechanism; and said template comprising a lower plate, first and second top plates, means for pivotally mounting said first and second top plates to said lower plate, said first and second top plates being closable each over a respective part of said lower plate to hold material to be stitched, a continuous guide track formed in said lower plate and engaged by said guide means, said guide track having first starting and finishing points for a stitching operation on material held by said first top plate and second starting and finishing points for a stitching operation on material held by said second top plate, said first and second finishing points being spaced respectively from said second and first starting points; and a plurality of first operating means, on said template at each of said finishing points, for engaging with said presser foot to operate said needle and template drive mechanisms when said engagement occurs.

6. Apparatus according to claim 5 in which said first and second operating ramps are contiguous, with said first operating ramp following and being higher than said second operating ramp.