WO1990014937A1

WO1990014937A1 - Footwear production

Info

Publication number: WO1990014937A1
Application number: PCT/GB1989/000628
Authority: WO
Inventors: Robert Henry Smith
Original assignee: Livingston & Doughty Limited
Priority date: 1988-02-17
Filing date: 1989-06-07
Publication date: 1990-12-13
Also published as: GB2215263A; GB8803625D0

Abstract

A last (20) mounted on a pivotable piston (18) and cylinder (19) assembly is loaded with a semi-formed shoe (24) while pivoted outwardly of a machine casing (10). The last (20) is then manually pivoted into line with a mould cavity (13) in an injection moulding head (11), and the piston (18) is extended to push a sole (26) of the shoe (24) against an opening of the cavity (13). Plastics material (preferably containing a filler such as wood flour) is injected into the cavity (13) thereby in in situ moulding a heel block (29) on the sole (26).

Description

FOOTWEAR PRODUCTION

This invention relates to a method of and apparatus for producing a heel block for an article of footwear.

During the production of certain items of footwear having injection-moulded soles, it is the conventional practice to nail a block made of wood, plastics or rubber to an insole prior to the injection moulding process, this block providing a foundation around which the heel part of the sole is formed. This is a labour intensive exercise.

It is an object of the present invention to obviate or mitigate this and other problems, associated with heel block formation.

According to a first aspect of the present invention, there is provided a method of producing a heel block for an article of footwear, comprising injection moulding a block of material in situ on a shoe insole in the region of the heel, and moulding the sole proper around the block such that the block becomes incorporated into a heel portion of the sole.

Preferably, the injection moulding is performed by placing the insole on a last, moving the last to bring the insole into juxtaposition with a mould cavity, and injecting said material into the mould cavity. Conveniently, the last is moved in a direction aligned with the mould cavity towards and away from a moulding head which contains the mould cavity. Advantageously, the last is pivotable into and out of alignment with the mould cavity, and the insole is placed upon the last when the last is pivoted out of alignment with the mould cavity.

Desirably, the block is moulded from a plastics material which may contain a filler, such as wood flour.

According to a second aspect of the present invention, there is provided apparatus for producing a heel block for an article of footwear, comprising an injection moulding head including a mould cavity which opens onto an external surface of the head, a last upon which is placed in- use a shoe insole and which confronts the opening of the mould cavity, and means operative to effect relative movement between the moulding head and the last into and out of a position wherein the last is juxtaposed to said opening, the last being pivotable into and out of line with the moulding cavity to facilitate placement of the insole onto the last.

The invention will now be further described, by way of example only, with reference to the accompanying drawings in which :

Figure 1 is a perspective view of apparatus according to the present invention;

Figure 2 is an underneath plan view of a mould which forms part of the apparatus shown in Figure 1; and

Figure 3 shows a stage in the production of a heel block for an article of footwear by a method according to the present invention.

Referring first to Figure 1, the illustrated apparatus comprises a main casing 10 surmounted by a moulding head 11. A mould 12 is positioned within the moulding head 11 so that a moulding cavity 13 (see Figure 2) opens onto a bottom surface 14 of the head. Also disposed within the head 11 is an injection mechanism 15 whereby material can be injected into the moulding cavity 13.

An upper front portion of the main casing 10 is inclined to the vertical and contains various knobs, dials, etc. 16 by which operation of the apparatus can be controlled and/or monitored. A central part of this portion is however cut away at 17 to accommodate a piston rod 18 of a piston and cylinder assembly 19. A last 20 is mounted on the upper end of the piston rod 18, and the assembly 19 is operable to displace the last 20 generally vertically into and out of a position 20' wherein it is juxtaposed to the mould cavity 13. The assembly 19 is pivotally mounted within the main casing 10 (as indicated generally in broken lines at 21) so that the last 20 can also be pivoted forwardly of the apparatus to a position 20" wherein it is out of alignment with the mould cavity 13. A foot pedal 22 controls operation of both the piston and cylinder assembly 19 and the injection mechanism 15.

Referring now also to Figure 3, the apparatus is employed during the production of a sole on a semi-formed article of footwear 24 (e.g. a shoe) comprising an upper 25 and an insole 26. Initially, the piston rod 18 is manually pulled forwardly of the apparatus so that the semi-formed shoe 24 can be loaded onto the last 20 with a heel portion 28 of the shoe 24 facing towards the main casing 10. The piston rod 18 is then manually pushed back towards the casing 10 to bring the last 20 (and more particularly the heel portion 28 of the shoe) into alignment with the mould cavity 13.

By operation of the foot pedal 22, the piston rod 18 is extended to move the last 20 and the shoe 24 upwardly into a position wherein the insole 26 in the region of the heel portion 28 presses against the downwardly-facing opening of the mould cavity ,13. Once the piston rod 18 has reached its fully extended position, the mechanism 15 operates automatically to inject material into the cavity 13 and thereby onto the insole 26. In this way, a block 29 .of that material is in situ moulded onto the- insole 26 in the heel region (see Figure 3). The material employed for the moulding operation is preferably a plastics containing wood flour as a filler, and may for example be a material as sold under the Registered Trade Mark CELLAX. Reference numeral 30 in Figure 1 denotes a hopper in the moulding head 11 into which the raw material is deposited.

Following the moulding operation, the piston rod 18 is automatically retracted, whereupon the rod can be manually pivoted forwardly of the apparatus to facilitate removal of the semi-formed shoe 24 from the last 20. A fresh shoe can then be loaded onto the last for a similar moulding operation. After removal from the last, the shoe 2^'4 is passed to a further stage in the manufacturing process wherein a sole proper is moulded onto the shoe and around the block 29. The block 29 is thus incorporated into the heel of the finished shoe, and takes the place of the wooden, plastics or rubber block which is conventionally nailed to the insole 26.

The above-described method is less labour intensive than the conventional nailing operation, and is particularly suited to mass production of footwear especially at the less expensive end of the range. Moreover, a seal is also created to prevent penetration of the molten sole material to the inside of the shoe via the lasted margin. Furthermore, the method eliminates the use of nails in the insole which can cause various problems.

Claims

CLAIMS :

1. A method of producing a heel block for an article of footwear, comprising injection moulding a block of material jLn situ on a shoe insole in the region of the heel, and moulding the sole proper around the block such that the block becomes incorporated into a heel portion of the sole.

2. A method as claimed in claim 1, wherein the injection moulding is performed by placing the insole on a last, moving the last to bring the insole into juxtaposition with a mould cavity, and injecting said material into the mould cavity.

3. A method as claimed in claim 2, wherein the last is moved in a direction aligned with the mould cavity towards and away from a moulding head which contains the mould cavity.

4. A method as claimed in claim 2 or 3 , wherein the last is pivotable into and -out of alignment with the mould cavity, and the insole is placed upon the last when the last is pivoted out of alignment with the mould cavity.

5. A method as claimed in any -preceding claim, wherein the block is moulded from a plastics material.

6. A method as claimed in claim 5, wherein the plastics material contains a filler.

7. A method as claimed in claim 6, wherein the filler is wood flour.

8. Apparatus for producing a heel block for an article of footwear, comprising an injection moulding head including a mould cavity which opens onto an external surface of the head, a last upon which is placed in use a shoe insole and which confronts the opening of the mould cavity, and means operative to effect relative movement between the moulding head and the last into and out of a position wherein the last is juxtaposed to said opening, the last being pivotable into and out of line with the moulding cavity to' facilitate placement of the insole onto the last.

9. Apparatus as claimed in claim 8, wherein an injection mechanism of the moulding head operates automatically when the last is moved into its said position juxtaposed to the mould cavity opening.

10. Apparatus as claimed in claim 8 or 9, wherein the last is moved into and out of its said position juxtaposed to the mould cavity opening by means of a piston and cylinder assembly.

11. Apparatus- as claimed in claim 8, 9 or 10, wherein the last is moved into and out of its said position juxtaposed to the mould cavity opening by operation of a foot pedal.

12. Apparatus as claimed in any one of claims 8 to 11, wherein the last is pivoted manually into and out of line with the moulding cavity by an operator of the apparatus.

13. A method of producing a heel block for an article of footwear, substantially as hereinbefore described with reference to the accompanying drawings.

14. Apparatus for producing a heel block for an article of footwear, substantially as hereinbefore described with reference to Figure 1 of the accompanying drawings.