GB2089193A

GB2089193A - Cutting upper blanks

Info

Publication number: GB2089193A
Application number: GB8039917A
Authority: GB
Original assignee: Shoe and Allied Trades Research Association
Current assignee: Shoe and Allied Trades Research Association
Priority date: 1980-12-12
Filing date: 1980-12-12
Publication date: 1982-06-23
Also published as: GB2089193B

Abstract

The lines along which material to form an upper is cut, for example by a press knife (Fig. 3), form closed figures (Fig. 4) which mesh together along undulating portions 42 which will be lasting margins. <IMAGE>

Description

SPECIFICATION Footwear The present invention concerns the manufacture of footwear such as boots and shoes.

Boots and shoes normally include an upper, produced from leather or a synthetic material and formed to the general contour of the upper part of a person's foot, and a sole portion to which the upper is attached.

In one common construction, the sole portion has a insole and a sole of similar outline, and a marginal portion of the upper is adhered between the two.

Manufacture of this type of boot or shoe involves forming a pattern for the upper to the desired shape, placing the insole within a marginal portion of the pattern, known as the lasting margin, supplying adhesive to the lasting margin, and folding this inwardly against the insole to secure the upper and the insole together. Subsequently, the sole is bonded to the inturned upper to produce a boot or shoe in which the upper is securely joined to the sole and insole in a concealed manner.

For this type of boot or shoe, the dimensions of the pattern for the upper are selected to allow for a lasting margin having a predetermined width. The full width is not required for achieving a good bond but is desirable for accommodating a slight misplacement of the upper relative to the insole before gluing or slight inaccuracies in the initial cutting of the upper which may result in a portion of the lasting margin having a diminished width for adhering to the insole. To ensure that any such diminished width is still adequate for forming a firm join, an excess allowance must be provided in the first place. Thus a certain amountofexcess material is presentwhich is effectively wasted.

Aside from this wastage of material in the width of the lasting margin, excess upper material is also generally present longitudinally of the margin at regions of the insole defining relatively sharp bends in the contour of the boot or shoe. This results in folds or pleats forming in the lasting margin which must be scoured flat prior to sole attachment.

The present invention from one aspect provides a pattern for an upper having a portion at least of its periphery formed with alternating projections and recesses.

More particularly, the invention provides such a pattern which has an undulating edge along at least a portion of the lasting margin.

With this arrangement, it is possible to obtain a saving in material in relation of the earlier type of upper pattern which is designed to provide a lasting margin of substantially constant width. The average width of the lasting margin in the present instance, where it has an undulating edge, may be reduced because even if the upper is slightly misplaced relative to the insole when the two are positioned for gluing and a reduction in the surface of one region of the lasting margin available to receive adhesive results, an adequate overlap between the lasting margin and the insole may still be achieved in this region, where each projection exists, to establish a good bond.

Furthermore, by providing the lasting margin with an undulating edge portion in a region where previously pleating could be expected, the occurrence of pleating may be minimised. The recesses in the lasting margin accommodate the material in the projections to a certain extent and allow these to fall into overlying relationship without significantfolding. The amount of scouring needed is thus minimised by giving the lasting margin its undulating edge when the pattern is first formed.

Not only does the invention enable the surface area of the pattern itself to be reduced but it also permits a reduction in the waste from the material from which the patterns are cut to be achieved.

Another aspect of the invention features a process for cutting upper patterns from a sheet of material, in which the lines along which the material is cut are arranged to form closed figures, each corresponding in shape to a respective upper pattern, which mesh together along undulating portions of their contours.

This arrangement of the figures which eventually form the patterns is feasible by virtue of the edge contours of the patterns according to the invention and permits closer and denser distribution of the pattern figures on the sheet of material than has previously been normal.

In one embodiment of the invention, the meshed regions of these figures have cycloidal contours. The use of cycloidal curves results in profiles which will mesh together whether the mean line of each is convex or concave and of the same or different curvature. In the present instance, it is advantageous for edge regions of the pattern figures whose mean lines have contours of differing curvature, either concave or convex, to be able to mesh together to achieve an optimum arrangement of the pattern figures on the sheet of material for minimising waste and so the use of cycloidal curves is desirable.

In order that patterns of different sizes and different components of the upper may also mesh together, the pitch and amplitude of the undulations is advantageously fixed, and does not vary according to size.

Additionally, the invention resides in a press knife adapted for use in the cutting process, the press knife having a cutting edge at least a portion of which alternates or undulates from one side to another of a mean line.

As before, the cutting edge preferably as a cycloidal form.

The invention is described further, by way of example, with reference to the accompanying drawings in which: Figure 1 is a plan view of an upper pattern in accordance with the invention; Figure 2 is an exploded perspective view of a shoe in accordance with the invention employing the upper pattern of Figure 1; Figure 3 is a perspective view of a press knife adapted for cutting the pattern from the sheet of material; and Figure 4 is a plan view of a sheet of material indicating the lines along which this is cut to produce a number of upper patterns such as the one illustrated in Figure 1.

Referring initially to Figure 1, this shows an upper pattern 10 for forming the front portion of the upper in a shoe such as is illustrated in Figure 2. The upper pattern 10 as a tongue 12, side portions 14 each with a margin 13, and a lasting margin 16 which has an undulating edge 18. The undulating edge 18 extends the full length of the lasting margin and is of generally cycloidal form. More particularly, the edge 18 is made up of alternating hypocycloidal segments 18a and epicycloidal segments 18b.

In order to produce a shoe using the upper pattern 10, this pattern is first attached, for example by switching along the margin 13, to a further upper pattern 20. Like the pattern 10, the pattern 20 has an undulating edge 22 of generally cycloidal form to its lasting margin 24.

After the component parts of the upper have been joined together the closed upper thus formed is stretched over a last and firmly attached to an insole 26 by way of the lasting margins 16, 24. In the present instance, this is achieved by applying adhesive along the interior face of each lasting margin and by folding the margins against the insole and applying pressure.

At the toe and heel of the shoe, a certain amount of pleating of the lasting margin is inevitable but the indentations in the lasting margin minimise the amount of pleating by allowing the projecting regions to overlie one another in a reasonably flat matter.

As shown in Figure 2, the width of the lasted margin thus produced varies along the periphery of the insole 26. Areas of narrow width alternate with areas of greater width, and a bonding contact between the areas of greater width and the insole is sufficient to attach the upper firmly to the insole even when the narower areas are themselves insufficiently wide to give a firm bond.

A sole 28 is finally joined to the insole 26 to complete the sole and in so doing to conceal the lasted margin of the upper.

It is envisaged that in a shoe such as the one shown in Figure 2 having a feather edge 625mm long, the lasting margin may be provided with an undulating edge having a pitch of 25mm, with the width of the lasting margin varying from a minimum of4mm to a maximum of 12mm. In a corresponding conventional shoe, the lasting margin would normally have a constant width of 12mm and so in the present instance the average width of the lasting margin is effectively reduced by4mm. This represents a reduction in pattern area of 625 x 4, or 2,500 sq. mm per shoe which, in practice, is a saving of up to 7% of material. The benefits of the pattern according to the invention are thus evident.

If the accuracy of lasting is insufficient, or that a planned minimum lasting margin of 4mm is inadequate, then a reduced material saving is available by haiving the pitch and amplitude of the undulations.

The process for producing the upper patterns 10 and 20 is as follows: A sheet of material such as leather is taken and a press knife such as the one shown in Figure 3 is placed on the material.

This press knife comprises a strip metal body 30 bent into the exact shape of the upper pattern to be produced by that press knife, the metal strip forming the body having its ends joined to provide a closed figure. An internal frame 32 is fitted within the body as shown in Figure 3 for strengthening purposes.

One edge of the strip forming the body 30 provides a cutting edge 34 of the knife. Like the corresponding upper pattern, this edge, of course, has an undulating generally cycloidal contour.

Once the press knife has been positioned on the material, a clicking press, in the form of a plate having a resilient pad on its lower surface is brought down into engagement with the upper face of the knife to force the knife into the material and punch the pattern from the material. The press is then withdrawn and the knife is repositioned, or a different knife is selected and positioned on the remaining portion of material.

By repeatedly using the same knife, or by forming the body of each knife to have undulations of a standard pitch and amplitude when different knives are used, the press knife or knives can be placed cutting edge downwards on the material from which the upper patterns are to be cut in such a manner as to result in interlocking of the pattern contours on the material.

Figure 4 shows on a section of material the lines along which the material is to be cut to produce a number of patterns similar to the pattern 10. These lines form closed Figures 40 each representing the line of contact betwen the cutting edge of one press knife and the material. Where the adjacent positions of the press knife 30 interlock with one another, the Figures 40 have meshed portions 42 as illustrated.

The Figures 40 may thus be more densely packed on the material than would be possible if the indentations in each knife and pattern were filled in to produce the smoother outline previously common.

Although, in the process described, the patterns have been cut sequentially from the material, they could alternatively be cut out simultaneously still using the arrangement of cutting lines which is illustrated in Figure 4. Another possibility is to cut the patterns out by hand or by using a computercontrolled cutting tool such as a laser, water jet or oscillating knife in place ofthe press knives.

The patterns which have been described have an undulating edge along the entire length of their lasting margins. In a modificaion of the invention, however, an undulating edge may be provided along one or more portions only of the lasting margin. For example, an undulating edge in the tow region only of an upper pattern for providing the front of a boot or shoe would give benefits in reducing the occurrence of folding in the lasted margin. Alternatively, by providing an undulating edge in the regions where the pattern figures lie most closely adjacent to one another on the material prior to cutting would permit meshing and consequent savings in material.

CLAIMS (filed on 11 Dec 1981) 1. A process for cutting upper patterns for shoes from a sheet of material, in which the lines along

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. illustrated in Figure 1. Referring initially to Figure 1, this shows an upper pattern 10 for forming the front portion of the upper in a shoe such as is illustrated in Figure 2. The upper pattern 10 as a tongue 12, side portions 14 each with a margin 13, and a lasting margin 16 which has an undulating edge 18. The undulating edge 18 extends the full length of the lasting margin and is of generally cycloidal form. More particularly, the edge 18 is made up of alternating hypocycloidal segments 18a and epicycloidal segments 18b. In order to produce a shoe using the upper pattern 10, this pattern is first attached, for example by switching along the margin 13, to a further upper pattern 20. Like the pattern 10, the pattern 20 has an undulating edge 22 of generally cycloidal form to its lasting margin 24. After the component parts of the upper have been joined together the closed upper thus formed is stretched over a last and firmly attached to an insole 26 by way of the lasting margins 16, 24. In the present instance, this is achieved by applying adhesive along the interior face of each lasting margin and by folding the margins against the insole and applying pressure. At the toe and heel of the shoe, a certain amount of pleating of the lasting margin is inevitable but the indentations in the lasting margin minimise the amount of pleating by allowing the projecting regions to overlie one another in a reasonably flat matter. As shown in Figure 2, the width of the lasted margin thus produced varies along the periphery of the insole 26. Areas of narrow width alternate with areas of greater width, and a bonding contact between the areas of greater width and the insole is sufficient to attach the upper firmly to the insole even when the narower areas are themselves insufficiently wide to give a firm bond. A sole 28 is finally joined to the insole 26 to complete the sole and in so doing to conceal the lasted margin of the upper. It is envisaged that in a shoe such as the one shown in Figure 2 having a feather edge 625mm long, the lasting margin may be provided with an undulating edge having a pitch of 25mm, with the width of the lasting margin varying from a minimum of4mm to a maximum of 12mm. In a corresponding conventional shoe, the lasting margin would normally have a constant width of 12mm and so in the present instance the average width of the lasting margin is effectively reduced by4mm. This represents a reduction in pattern area of 625 x 4, or 2,500 sq. mm per shoe which, in practice, is a saving of up to 7% of material. The benefits of the pattern according to the invention are thus evident. If the accuracy of lasting is insufficient, or that a planned minimum lasting margin of 4mm is inadequate, then a reduced material saving is available by haiving the pitch and amplitude of the undulations. The process for producing the upper patterns 10 and 20 is as follows: A sheet of material such as leather is taken and a press knife such as the one shown in Figure 3 is placed on the material. This press knife comprises a strip metal body 30 bent into the exact shape of the upper pattern to be produced by that press knife, the metal strip forming the body having its ends joined to provide a closed figure. An internal frame 32 is fitted within the body as shown in Figure 3 for strengthening purposes. One edge of the strip forming the body 30 provides a cutting edge 34 of the knife. Like the corresponding upper pattern, this edge, of course, has an undulating generally cycloidal contour. Once the press knife has been positioned on the material, a clicking press, in the form of a plate having a resilient pad on its lower surface is brought down into engagement with the upper face of the knife to force the knife into the material and punch the pattern from the material. The press is then withdrawn and the knife is repositioned, or a different knife is selected and positioned on the remaining portion of material. By repeatedly using the same knife, or by forming the body of each knife to have undulations of a standard pitch and amplitude when different knives are used, the press knife or knives can be placed cutting edge downwards on the material from which the upper patterns are to be cut in such a manner as to result in interlocking of the pattern contours on the material. Figure 4 shows on a section of material the lines along which the material is to be cut to produce a number of patterns similar to the pattern 10. These lines form closed Figures 40 each representing the line of contact betwen the cutting edge of one press knife and the material. Where the adjacent positions of the press knife 30 interlock with one another, the Figures 40 have meshed portions 42 as illustrated. The Figures 40 may thus be more densely packed on the material than would be possible if the indentations in each knife and pattern were filled in to produce the smoother outline previously common. Although, in the process described, the patterns have been cut sequentially from the material, they could alternatively be cut out simultaneously still using the arrangement of cutting lines which is illustrated in Figure 4. Another possibility is to cut the patterns out by hand or by using a computercontrolled cutting tool such as a laser, water jet or oscillating knife in place ofthe press knives. The patterns which have been described have an undulating edge along the entire length of their lasting margins. In a modificaion of the invention, however, an undulating edge may be provided along one or more portions only of the lasting margin. For example, an undulating edge in the tow region only of an upper pattern for providing the front of a boot or shoe would give benefits in reducing the occurrence of folding in the lasted margin. Alternatively, by providing an undulating edge in the regions where the pattern figures lie most closely adjacent to one another on the material prior to cutting would permit meshing and consequent savings in material. CLAIMS (filed on 11 Dec 1981)

1. A process for cutting upper patterns for shoes from a sheet of material, in which the lines along

which the material is cut are arranged to form closed figures, each corresponding in shape to a respective upper portion, which mesh together along undulating portions of their contours.

2. A process as claimed in claim 1, in which the lines along which the material is cut undulate only where the closed figures mesh together.

3. A process as claimed in claim 1, in which the lines along which the material is cut undulate at regions of the closed figures spaced from the regions where they mesh together.

4. A process as claimed in claim 3, in which the lines along which the material is cut undulate over substantially the entire region of each closed figure corresponding to the lasting margin of a respective upper pattern.

5. A process as claimed in any preceding claim, in which the undulations are of generally cycloidal form.

6. A process as claimed in claim 5, in which the undulations have a combination of generally hypocycloidal segments and generally epicycloidal segments.

7. A process as claimed in any preceding claim, in which the amplitude of the undulations is substantially the same for each pattern.

8. A process as claimed in any preceding claim, in which the pitch of the undulations is substantially the same for each pattern.

9. A process as claimed in any preceding claim, in which the lines along which the material is cut are arranged to form closed figures of varying sizes.

10. A process as claimed in any preceding claim, in which the lines along the material is cut are arranged to form closed figures of varying shapes.

11. A process as claimed in any preceding claim, in which the closed figures are cut successively from the material.

12. A process as claimed in any of claims 1 to 10, in which the closed figures are cut simultaneously from the material.

13. A press knife for cutting upper patterns from a sheet of material, having a cutting edge at least a portion of which undulates from one side to another of a mean line.

14. A knife as claimed in claim 13, in which the portion of the cutting edge for cutting the lasting margin of an upper pattern undulates along part of its length.

15. A knife as claimed in claim 13, in which the portion of the cutting edge for cutting the lasting margin of an upper pattern undulates along its full length.

16. A knife as claimed in any of claims 13 to 15, in which the undulations are of generally cycloidal form.

17. A knife as claimed in claim 16, in which the undulations comprise a combination of generally hypocycloidal segments and generally epicycloidal segments.

18. An upper pattern for a shoe having a portion at least of its periphery formed with alternating projections and receses.

19. An upper pattern as claimed in claim 18, having an undulating edge along at least a portion of the lasting margin.

20. An upper pattern as claimed in claim 19, having a toe section and in which the undulating edge is provided along the lasting margin of the toe section.

21. An upper pattern as claimed in claim 19 or 20, in which the undulating edge is provided along a plurality of portions of the lasting margin.

22. An upper pattern as claimed in any of claims 19 to 21, in which the undulating edge is provided along the entire lasting margin.

23. An upper pattern as claimed in any of claims 18 to 22, in which the undulations are of generally cycloidal form.

24. An upper pattern as claimed in claim 23, in which the undulations comprise a combination of generally hypocycloidal segments and generally epicycloidal segments.

25. An upper pattern formed by the process of any of claims 1 to 12.

26. An upper pattern formed by the press knife of any of claim 13 to 17.

27. A shoe formed with an upper pattern as claimed in any of claims 18 to 26.

28. A process for cutting upper patterns from a sheet of material substantially as herein particularly described with reference to the accompanying drawings.

29. A press knife for cutting upper patterns from a sheet of material substantially as herein particularly described with reference to and as illustrated in Figure 3 of the drawings.

30. A shoe substantially as herein particularly described with reference to and as illustrated in Figure 2 of the accompanying drawings.

30. An upper pattern substantially a herein particularly described with reference to and as illustrated in Figures 1,2 and 4 of the accompanying drawings.