GB2167456A

GB2167456A - Stitching composite workpieces

Info

Publication number: GB2167456A
Application number: GB08429693A
Authority: GB
Inventors: Anthony Mark Garley
Original assignee: British United Shoe Machinery Ltd
Current assignee: Noxet UK Ltd
Priority date: 1984-11-23
Filing date: 1984-11-23
Publication date: 1986-05-29
Also published as: GB8429693D0

Abstract

A pallet for use in stitching composite workpieces comprises an assembly of base, intermediate and top plate members (10, 22, 28, 32, 40) having workpiece component location means (24, 36) and channels (20, 38, 42) through which the needle (not shown) of a sewing machine can pass. In order to enable stitching to take place up to the very edge of one of the components (A), or indeed off such edge, one (32) of the intermediate plates (22, 28, 32) providing second workpiece component location means (36) for the component (A) is of flexible sheet material. This plate (32) is secured to the under-side of another intermediate plate (28) for better supporting it. When the pallet is in a closed condition, the channel (38, 42) leaves a portion of the component and a portion of the adjacent region, which provides the second workpiece component location means (36) of the plate (32) of flexible sheet material, exposed sufficiently to enable not only the needle to pass therethrough, but also to accommodate the presser foot associated with the needle in such a manner that it can rest partly on the margin of the workpiece component (A) and partly on the margin of the plate (32) defining the location means (36). <IMAGE>

Description

SPECIFICATION Stitching composite workpieces This invention is concerned with stitching composite workpieces, more especially with a pallet for use in stitching composite workpieces comprising an assembly of base, intermediate and top plate members providing aligned workpiece component location means and channels through which the needle of a sewing machine can pass.

One such pallet is described in GB-A 1473687 and comprises an assembly of base, intermediate and top plate members of a rigid sheet material, e.g.

aluminium, hinged together in "book" fashion. In use, a first component of a workpiece is located adjacent the base plate by an intermediate member having workpiece component location means and thereafter a further component or further components can be located, in a desired relationship with the first-mentioned component, using further intermediate members also provided with workpiece component location means. The top and base members are each provided with channels through which the needle of a sewing machine can pass, and in addition each workpiece component location means provides such a channel.

A problem which has been found to arise when using such a pallet derives from the fact that, although the path of a needle relative to the workpiece components can be controlled with reasonable accuracy, if it is desired to stitch close to the edge of one component when the latter is located by the workpiece component location means provided by a plate member of rigid material, the danger always arises of the needle striking against the plate member with consequent damage, usually breakage, of the needle.

Consequently, it is the usual practice to space the line of stitching at a small distance from the edge of the component. Nevertheless, there is sometimes a need to stich up to the very edge of the component, or indeed in some instances, usually for decorative effects, to stitch off the edge of the component but adjacent to it, and this cannot be achieved with certainty, or indeed without risk of damage, using currently conventional automatic sewing machines.

It is thus an object of the present invention to provide an improved pallet for use in stitching composite workpieces, which pallet enables the line of stitching to be formed at the very edge of a component, or indeed off such edge, without consequent risk of damage to the needle.

The invention thus provides, in one of its several aspects, a pallet for use in stitching composite workpieces comprising an assembly of base, intermediate and top plate members providing aligned workpiece component location means and channels through which the needle of a sewing machine can pass, wherein at least one of the intermediate plate members providing workpiece component location means is of flexible sheet material.

It will thus be appreciated that, by using a plate member of flexible sheet material which provides workpiece component location means, even if the needle deviates from its controlled path and engages the plate member, the effect will merely be to deflect the edge of the plate member without damage to the needle. Moreover, it is now possible, using the pallet in accordance with the present invention, to enable the needle to pass between the workpiece edge and the location edge provided by the plate member of flexible sheet material, again without damage to the needle.

In the pallet described in GB-A 1473687, because there was a minimum distance beyond which it would not be safe for the needle to approach the workpiece location means provided by the plate member of rigid sheet material, it has been conventional for the workpiece component location means to be aligned with the channels formed in other plate members. In particular, where the workpiece component location means is constituted by a cut-out in a plate member, the same data could then be used for forming both the channels and the cut-outs.In the pallet according to the present invention, on the other hand, in order especially to enable the needle to be located in close relation with the edge of the workpiece, preferably the channels and workpiece component location means are so arranged and dimensioned that when the assembly is closed the plate member of flexible sheet material is left exposed, in the region of the portion thereof providing the location means, at least by the channel(s) formed in the plate member(s) above it.

In conventional sewing machines, a presser foot is usually provided by which as the needle is retracted, the material of the workpiece is held in position; typical of a presser foot, therefore, is a circular member having a central aperture through which the needle can pass. It will thus be appreciated that, using such a sewing machine, the minimum distance between the workpiece component edge and the path of the needle must be such that the presser foot does not, when operative, engage the rigid plate members but rather rests wholly on the workpiece, since in general if the presser foot engages the rigid plate members, it will be held spaced from the workpiece and not fulfil its presser foot function, so that the workpiece component could become dislodged as the needle is withdrawn.In using the pallet in accordance with the present invention, on the other hand, the portion exposed as aforesaid by the channel(s) may be so dimensioned as to allow the presserfootofa sewing machine to rest on said portion when the needle is following a path corresponding to the edge of a workpiece component positioned by the location means of the plate member of flexible sheet material. It will of course be appreciated that, because the sheet material is yieldable, the presser foot is held in pressing engagement with the workpiece component, even when it rests partially on the plate member of flexible sheet material.

In order to ensure that, in the assembly of plate members, the plate member of flexible sheet material is correctly positioned for its workpiece component location function, preferably it is secured to another plate member of the assembly.

For the most efficient use, furthermore, it should be secured to the under-side of such other plate member. In such a case said other plate member preferably has an aperture formed therein corresponding to the workpiece component location means of the plate member of flexible sheet material but larger than said location means, thereby leaving said location means exposed. Of course, where the pallet is intended for a machine comprising a presser foot, as above described, preferably the portion of the plate member of flexible sheet material exposed by the aperture of said other plate member is so dimensioned as to allow the presser foot of a sewing machine to rest on said portion when the needle of such machine is following a path corresponding to the edge of a workpiece component positioned by the location means of the plate member of flexible sheet material.

If desired, in using a pallet in accordance with the present invention, the workpiece component may be temporarily attached to another workpiece component be stitched when initially located in the pallet. In such circumstances, it may be possible to dispense with the clamping of the workpiece component for the stitching operation, and rely merely upon the temporary attachment, together with the action of the workpiece component location means. In general, however, it will be desirable to clamp each component when located, and thus it would not be appropriate for said other plate member to which the plate member of flexible sheet material is secured to be constituted by the top plate member.Similarly, while, as e.g. in the case of the pallet of GB-A 1473687, a workpiece component rests on the base plate, being located thereon by workpiece component location means provided by an intermediate plate member, it would be possible for the base plate itself to provide the workpiece component location means, the component then resting on the bed of the machine. In such a case it would then be possibleforthe plate member of flexible sheet material to itself form the base plate.

In general, however, since the loading of components into pallets tends to take place remote from the machine, a conventional "bookform" pallet will preferably have base and top plate members which merely fulfil a clamping function and in such a case said other plate member to which the plate member of flexible sheet material is secured would be constituted by an intermediate member.

The flexible sheet material of which the plate member is made should be sufficiently selfsupporting for its unsupported portion to be able to provide an accurate workpiece component location means. One suitable material has been found to be a poromeric shoe upper material identified as "Clarino". ("Clarino" is a registered trade mark.) The invention also provides, in another of its several aspects, a method of clamping workpiece components in a desired relationship one with another for a joining-by-stitching operation to be performed thereon, wherein the components are clamped together adjacent the stitching region but leaving said region unclamped, characterised in that at least one of the components is located in relationship to the other component(s) by means of a member of flexible sheet material having a cut-out corresponding to the contour of the component and is held by said member in such location during the stitching operation.

There now follows a detailed description, to be read with reference to the accompanying drawings, of one pallet in accordance with the invention and a method of clamping workpiece components using such pallet, this pallet and this method having been selected for description merely by way of nonlimiting example.

In the accompanying drawings: Fig. is a perspective view of a "book" pallet, in open condition, showing an intermediate plate member of flexible sheet material secured to the under-side of a further intermediate plate member of rigid material; Fig. 2 is a plan view of a top plate of said pallet; Fig. 3 is a plan view of the intermediate member of rigid material to which the intermediate member of flexible sheet material is secured; Fig. 4 is a fragmentary section view along the lines IV--IV of Fig. 3; Fig. 5 is a plan view of a sub-assembly of base and intermediate plate members; and Figs. 6 and 7 are plan views of two components to be joined by stitching using the pallet in accordance with the invention.

The pallet now to be described comprises a base plate 10 af aluminium sheet material, at one side of which is provided a location strip 12 having at opposite ends notches 14 by which the pallet can be located in an automatic sewing machine. The strip 12 also carries four hinge portions 16 by which the other plate members can be assembled with the base plate in bookform, as will be hereinafter described. The base plate also carries two upwardly projecting grooved pins 18forclamping purposes, also as will be hereinafter described. The base plate is also formed with two generally horseshoe-shaped channels 20 through which the needle (not shown) of a sewing machine can pass.It will be appreciated that the pallet now being described is suitable for locating two sets of workpiece components arranged side-by-side, as can be understood from Fig. 5.

Secured, e.g. by bonding, to the base plate 10 is a first intermediate plate 22 of aluminium sheet material which is provided with two cut-outs 24 for receiving a vamp V (see Fig. 6), constituting a first workpiece component, which is supported from beneath by the base plate 10. It will be observed from Fig. 5 that the channel 20 is exposed by the cutout 24 in each case, the cut-out 24 thus including a channel through which the needle of a sewing machine can pass. It will also be observed from Fig.

5 that the channel 20 is disposed relatively close to the edge of a vamp V located by the cut-out 24. (The cut-out 24 constitutes a first workpiece component location means of the pallet in accordance with the invention.) The plate 22 is provided with circular apertures 26 through which the pins 18 project.

In Fig. 3 is shown a further intermediate plate member 28 of aluminium, said plate being provided with two hinge portions 30 by which it can be hingedly mounted on two of the hinge portions 16 provided on the strip 12 carried on the base plate 10.

Bonded to the under-side of the plate 28 is another plate 32 which in this case is formed of a flexible sheet material. In the pallet now being described, this sheet material is a poromeric shoe upper material identified as "Clarino". The flexible sheet material is self-supporting over the relatively small area where (as can be seen in Fig. 3) it is unsupported by the rigid plate 28. Both plates 28,32 are provided with holes 34 for the pins 18.

The plate 32 is provided with two cut-outs 36 which are shaped corresponding to the apron A shown in Fig. 7, which apron A is to be joined by stitching to a vamp V located at 24. The cut-out 36 thus consitutes a second workpiece component location means of the pallet. The plate 28 is also provided with cut-outs 38, which are generally similarly shaped to the cut-outs 36 but of larger dimensions leaving marginal portions of the cutouts 36 (and thus the second workpiece component location means) exposed and unsupported.

In Fig. 2 is shown a top plate 40 of the pallet having two channels 42 through which the needle ot a sewing machine can pass and which are generally similar in shape and disposition to the channels 20 of the base plate 10. In addition, the top plate 40 has hinged portions 44 by which the plate in hingedly mounted to another pair of the hinged portions 16 on the trip 12 and also has two holes 46 through which the pins 18 project when the pallet is in its closed condition. The top plate 40 also carries two spring clamp arrangements 44 having bifurcated ends which can engage about the pins 18, locating in the grooves thereof.

When the pallet is in a closed condition, the associated channels 20,42 are aligned with each other and the outside edges thereof are also aligned with the outer edge of the associated cut-out 38, thereby leaving exposed, when the pallet is in its closed condition, the region of the plate 32 of flexible material providing the second workpiece component location means. As will be seen from Fig. 3, furthermore, the exposed region of said plate 32 is sufficiently broad not only to enable a needle to follow a path coincident with the edge of the cut-out 36, but also to accommodate within the channel 42 the presser foot (not shown) associated with said needle. In this way, it will be appreciated, stitching up to the very edge of the apron A located in the cutout 36 is possible, and indeed off said edge, if such stitching is required.

In carrying out the method in accordance with the invention, with the pallet in its open condition vamps V are placed in the two cut-outs 24, whereafter the further intermediate plate 28 is hinged thereover and aprons A are located in the cut-outs 36. In this condition the vamps V and associated aprons A are located in a desired relationship with one another for a joining-bystitching operation to be performed thereon. The top plate is now hinged down over the aprons A and the spring clamps 48 are closed to secure the pallet in its now closed condition. The edge of each apron A and the adjacent portion of the plate 32 of flexible material, providing the second workpiece component location means, is exposed through the channels 42 when the pallet is in this condition.On the other hand, the aprons A are held clamped in position at this stage by the re-entrant portions 50 embraced within the horseshoe-shaped cut-outs 42 of the top plate 40, only the exposed portions hereinbefore referred to remaining unclamped. The width of each channel 42 is of such dimensions that not only the needle can pass therethrough but also the presser foot associated with the needle can be accommodated within the confines of the channel.

Furthermore, because a portion of the plate 32 of flexible sheet material is exposed, it is possible, in carrying out this method, for the needle to follow a path along the very edge of the apron A, or indeed to stitch by penetrating between the edge of the plate 32 and the apron A, the plate edge yielding as the needle passes therebetween. When such a path is being followed, furthermore, the presser foot can rest partly on the margin of the plate 32 and partly on the margin of the apron A.

Claims

1. A pallet for use in stitching composite workpieces comprising an assembly of base, intermediate and top plate members providing aligned workpiece component location means and channels through which the needle of a sewing machine can pass, wherein at least one of the intermediate plate members providing workpiece component location means is of flexible sheet material.

2. A pallet according to Claim 1 wherein the channels and workpiece component location means are so arranged and dimensioned that, when the assembly is closed, the plate member of flexible sheet material is left exposed, in the region of the portion thereof providing the location means, at least by the channel(s) formed in the plate member(s) above it.

3. A pallet according to Claim 2 wherein the portion of the plate member of flexible sheet material thus exposed by the channel(s) is so dimensioned as to allow the presser foot of a sewing machine to rest on said portion when the needle of such machine is following a path corresponding to the edge of a workpiece component positioned by the location means of the plate member of flexible sheet material.

4. A pallet according to either one of Claims 2 and 3 wherein the plate member of flexible sheet material is secured to the under-side of another plate member of said assembly.

5. A pallet according to Claim 1 wherein the plate member of flexible sheet material is secured to another plate member of the assembly, said other member having an aperture formed therein corresponding to the workpiece component location means of the plate member of flexible sheet material but larger than said location means, thereby leaving said location means exposed.

6. A pallet according to Claim 5 wherein the portion of the plate member of flexible sheet material exposed by the aperture of said other plate member is so dimensioned as to allow the presser foot of a sewing machine to rest on said portion when the needle of such machine is following a path corresponding to the edge of a workpiece component positioned by the location means of the plate member of flexible sheet material.

7. A pallet according to any one of Claim 3, 5 and 6 or to Claim 4 when tied to Claim 3 wherein the other plate member to which the plate member of flexible sheet material is secured is an intermediate member.

8. A pallet according to any one of the preceding Claims wherein the flexible sheet material is a poromeric material.

9. A method of clamping workpiece components in a desired relationship one with another for a joining-by-stitching operation to be performed thereon, wherein the components are clamped together adjacent the stitching region but leaving said region unclamped, characterised in that at least one of the components is located in relation to the other component(s) by means of a member of flexible sheet material having a cut-out corresponding to the contour of the component and is held by said member in such location during the stitching operation.

10. A pallet for use in stitching composite workpieces constructed arranged and adapted to be used substantially as hereinbefore described with reference to the accompanying drawings.

11. A method of clamping workpiece components in a desired relationship one with another for a joining-by-stitching operation to be performed thereon carried out substantially as hereinbefore described with reference to the accompanying drawings.