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Title:
SHANKLESS INSOLE FOR AN ITEM OF FOOTWEAR
Document Type and Number:
WIPO Patent Application WO/2018/002835
Kind Code:
A1
Abstract:
The shankless insole with which the invention is concerned has a rear part (12) extending forwardly from a heel end (12.1) to a midfoot end (12.2) and a flexible front part (14) extending rearwardiy from a toe end (14.1) to a midfoot end (14.2). The rear part is formed as a one-piece plastics premould shaped to conform to the shape of a last which wii! subsequently be used during manufacture of the item of footwear of one piece. It has a rear portion (12.3) of sufficient thickness to render it substantially rigid and a front portion (12.4) at the midfoot end which is thinner than the rear portion so as to have a degree of flexibility. The midfoot end of the front part and the front portion of the rear part are connected to one another in an overlapping relationship. The invention also concerns methods by which the shankless insole and the item of footwear are manufactured.

Inventors:
BASSAGE JOHN JAMES (ZA)
Application Number:
PCT/IB2017/053860
Publication Date:
January 04, 2018
Filing Date:
June 28, 2017
Export Citation:
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Assignee:
MYGANOX (PTY) LTD (ZA)
International Classes:
A43B13/38; A43B13/14; A43B13/41
Domestic Patent References:
WO2008037977A22008-04-03
Foreign References:
GB1489605A1977-10-26
FR2895649A12007-07-06
FR2136950A11972-12-29
EP0525324A11993-02-03
GB823685A1959-11-18
EP0488727A11992-06-03
GB1521682A1978-08-16
DE202011000863U12011-08-09
BE868277A1978-10-16
Other References:
None
Attorney, Agent or Firm:
SPOOR & FISHER et al. (ZA)
Download PDF:
Claims:
CLAIMS

1.

A shankless insole for an item of footwear, the insole comprising a rear part extending forward!y from a hee! end to a midfoot end and a flexible front part extending rearwardly from a toe end to a midfoot end, the rear part being a one-piece plastics premould shaped to conform to the shape of a last which will subsequently be used during manufacture of the item of footwear, the rear part having a rear portion of sufficient thickness to render it substantially rigid and a front portion at the midfoot end which is thinner than the rear portion so as to have a degree of flexibility, the midfoot end of the front part and the front portion of the rear part being connected to one another in an overlapping relationship.

2.

A shankless insole according to claim 1 wherein the rear portion of the rear part of the insole meets the front portion of the rear part of the insole at a step.

3.

A shankless insole according to claim 2 wherein the height of the step is similar to the thickness of the front part of the insole at the midfoot end thereof.

4.

A shankless insole according to claim 2 or claim 3 wherein the midfoot end of the front part of the insole overlaps the front portion of the rear part of the insole with a rear extremity of the midfoot end of the front part of the insole adjacent the step.

5.

A shankless insole according to claim 4 wherein, at the step, an upper surface of the rear portion of the rear part of the insole is substantially flush with an upper surface of the midfoot end of the front part of the insole.

6.

A shankless insole according to any one of the preceding claims wherein a midfoot region of the insole, formed by the connected and overlapping midfoot ends of the front and rear parts of the insole, is more flexible than the rear portion of the rear part of the insole but less flexible than a front region of the front part of the insole situated forwardly of the midfoot end of the front part.

7.

A shankless insole according to any one of the preceding claims wherein the rear portion of the rear part of the insole has a thickness which diminishes in a forward direction.

8.

A shankless insole according to any one of the preceding claims wherein an underside of the rear portion of the rear part of the insole is formed with an integral, thickened bar formation extending in a forward/rearward direction, the bar formation being located centrally between opposite sides of the rear portion.

9.

A shankless insole according to any one of the preceding claims wherein the rear part of the insole is moulded in one piece of a high impact polystyrene.

10.

A shankless insole according to any one of the preceding claims wherein the front part of the insole is of moulded fibreboard construction.

11.

A method of making a shankless insoie for an item of footwear, the method comprising the following steps:

forming a rear insole part as a one-piece plastics premould conforming to the shape of a last which will be used during manufacture of the item of footwear, the rear insole part extending forwardly from a heel end to a midfoot end and having a rear portion of sufficient thickness to render it substantially rigid and a front portion at the midfoot end which is thinner than the rear portion so as to have a degree of flexibility;

providing a flexible front insole part which extends rearwardly from a toe end to a midfoot end; and

connecting the midfoot end of the front part of the insole to the front portion of the rear part of the insole in an overlapping relationship.

12.

A method according to claim 11 comprising the step of forming an underside of the rear portion of the rear insole part with an integrally moulded thickened bar formation extending in a forward/rearward direction and located centrally between opposite sides of the rear portion.

13.

A method according to claim 11 or clam 12 wherein the midfoot end of the front part of the insole is arranged to extend over the front portion of the rear part of the insole.

14.

A method according to any one of claims 11 to 13 wherein the front portion of the rear part of the insole and the midfoot end of the front part of the insoie are connected to one another by adhesive.

15.

A method of manufacturing an item of footwear comprising the steps of making a shanktess insole using a method according to any one of claims 11 to 14 and incorporating the insoie, on a last, with other components of the item of footwear.

Description:
SHANKLESS INSOLE FOR AN ITEM OF FOOTWEAR'

BACKGROUND TO THE INVENTION

THIS invention relates to a shankless insole for an item of footwear and to a method for making the insole.

The insoles of many different types of heeled footwear, such as shoes and boots, are reinforced in a region extending forwardly from the heel to the midfoot by a separate, rigid shank. The shank, which may be made of steel or other suitably stiff material, is typically located between upper and lower parts of the insole which are stuck together and may be anchored in position by rivets or the like that fasten it to the lower insole part. However, the provision of a shank increases the cost and complexity of manufacturing the item of footwear. The present invention addresses this problem.

SUMMARY OF THE INVENTION

According to one aspect of the invention there is provided a shankless insole for an item of footwear, the insole comprising a rear part extending forwardly from a heel end to a midfoot end and a flexible front part extending rearwardly from a toe end to a midfoot end, the rear part being a one-piece plastics premould shaped to conform to the shape of a last which will subsequently be used during manufacture of the item of footwear, the rear part having a rear portion of sufficient thickness to render it substantially rigid and a front portion at the midfoot end which is thinner than the rear portion so as to have a degree of flexibility, the midfoot end of the front part and the front portion of the rear part being connected to one another in an overlapping relationship. Preferably the rear portion of the rear part of the insole meets the front portion of the rear part of the insole at a step. The height of this step may be similar to the thickness of the front part of the insole at the midfoot end thereof. In the preferred insole, the midfoot end of the front part of the insole overlaps the front portion of the rear part of the insole with a rear extremity of the midfoot end of the front part of the insole adjacent the step. It is also preferred that, at the step, an upper surface of the rear portion of the rear part of the insole is substantially flush with an upper surface of the midfoot end of the front part of the insole.

A midfoot region of the insole, formed by the connected and overlapping midfoot ends of the front and rear parts of the insole, is typically more flexible than the rear portion of the rear part of the insole but less flexible than a front region of the front part of the insole situated forwardly of the midfoot end of the front part.

An underside of the rear portion of the rear part of the insole may be formed with an integral, thickened bar formation extending in a forward/rearward direction, the bar formation being located centrally between opposite sides of the rear portion.

According to another aspect of the invention there is provided a method of making a shankless insole for an item of footwear, the method comprising the following steps:

forming a rear insole part as a one-piece plastics premould conforming to the shape of a last which will be used during manufacture of the item of footwear, the rear insole part extending forwardly from a heel end to a midfoot end and having a rear portion of sufficient thickness to render it substantially rigid and a front portion at the midfoot end which is thinner than the rear portion so as to have a degree of flexibility;

providing a flexible front insole part which extends rearwardly from a toe end to a midfoot end; and connecting the midfoot end of the front part of the insole to the front portion of the rear part of the insole in an overlapping relationship.

According to yet another aspect of the invention there is provided a method of manufacturing an item of footwear comprising the steps of making a shank!ess insole using the above method and incorporating the insole, on a last, with other components of the item of footwear.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in more detail, by way of example only, with reference to the accompanying drawings.

In the drawings:

Figure 1 shows an exploded perspective view of a first embodiment of shankless insole according to the present invention;

Figure 2 shows a perspective view of the assembled insole seen in

Figure 1 ;

Figure 3 shows a cross-section at the line 3-3 in Figure 2;

Figure 4 shows a perspective, view of the rear part of a second embodiment of shankless insole according to the present invention;

Figure 5 shows a side view of the rear part seen in Figure 4; and

Figure 6 shows a cross-section at the line 6-6 in Figure 5. DESCRIPTION OF THE ILLUSTRATED EMBODI ENTS

The tnsole 10 illustrated in Figures 1 and 2 is designed for use in a shoe with a low heel, and includes a rear part 12 and a front part 14. The rear part 12 is premouided in one piece of a suitable plastics material, in this case high impact polystyrene. It extends forwardly from a heel end 12.1 to a midfoot end 12.2 and includes a rear portion 12.3 and a front portion 12.4.

Although the thickness of the front portion 12.4 diminishes in a forward direction, it is somewhat thinner throughout than the rear portion 12.3. There is a step 12.5 between the rear portion 12.3 and the front portion 12.4. The thickness of the front portion 12.4 is sufficiently small for this portion to have a degree of resilient flexibility throughout although, as a result of its diminishing thickness, this flexibility increases in the forward direction.

The front portion flares outwardly in width in a forward direction, i.e. the width of the front portion at its forward edge 12.6 is greater than its width adjacent the step 12.5.

The premouided rear part is shaped to conform to the shape of a shoe last which will subsequently be used during manufacture of the shoe. It has a concave curvature in a transverse direction, i.e. in a direction extending between its lateral edges 12.7 and 12.8, which conforms to the shape of the last and which enhances wearer comfort in use.

The front part 14 of the insole 10 is resiliency flexible throughout and is made of moulded ftbreboard of a type conventionally used in shoe insoles. It extends rearwardly from a toe end 14.1 to a midfoot end 14.2. The front part 14 has a concave curvature in a transverse direction, i.e. in a direction extending between its lateral edges 14.3 and 14.4, once again selected to suit the shape of the shoe last and to enhance wearer comfort in use. The midfoot end 14.2 flares outwardly in width, in a forward direction, in a manner similar to the outward flare of the front portion 12.4 of the rear part 12. At its rear edge 14.5, the width of the midfoot end 14.2 is similar to that of the front portion 12.4 adjacent the step 12.5.

The thickness of the rear portion 12.3 of the rear part 12 may diminish, preferably in a progressive manner, in a forward direction. While this diminishing thickness of the rear portion 12.3 can provide a progressive increase in flexibility in the forward direction, the rear portion as a whole is substantially more rigid throughout than the front part 14 of the insole, i.e. the rear portion 12.3 of the rear part 12 is relatively rigid in comparison to the front part 14.

The insole is assembled by connecting the midfoot end of the front part 14 to the midfoot end of the rear part 12 in overlapping relationship. In practice, the midfoot end 14.2 of the front part 14 is placed over and adhered, by means of a suitable adhesive, to the front portion 12.4 at the midfoot end of the rear part 12. The rear edge 14.5 of the front part 14 is adjacent to and preferably in abutment with the step 12.5. This is shown in Figure 2 which also shows that there is a smooth transition between the side edges of the respective parts at the connection.

The thickness of the front part 14, at least at the midfoot end 14.2, is similar to the height of the step 12.5 between the rear portion 12.3 and the front portion 12.4 of the rear part. Accordingly, when the midfoot ends of the respective parts are connected to one another there is a smooth transition between the upper surfaces of the parts, i.e. the upper surfaces are substantially flush with one another at the step, in order to promote wearer comfort in use, as indicated by the arrow 16 in Figure 3.

The assembled insole seen in Figures 2 and 3 can now be taken to the last for assembly, in a conventional manner which will be well known to persons skilled in the art of footwear manufacture, with other conventional components to form the finished shoe. Figures 4 to 6 illustrate the premoulded rear part 100 of a second embodiment of insole according to the invention. The insole in this case is designed for use with a high heel shoe, typically a ladies' shoe with a heel pitch of 40mm or more. The shape of the rear part 100, and the loading which will be applied to it in use, are such that extra reinforcement is required in a region 102 of the rear portion 104 of the rear part 00.

The necessary extra reinforcement is provided by a thickened bar formation 106 which extends in a forward/rearward direction. The bar formation is integral with the remainder of the rear part 100, i.e. the rear part, including the bar formation, is moulded in one piece. The plastics materia! used may be a high impact polystyrene as in the first embodiment. The rear end of the bar formation 104 is located some distance in front of the rear end of the rear portion 104 and the front end of the bar formation is located some distance to the rear of the step 110. As will be apparent from Figure 6, the bar formation is located centrally between the opposite side edges 112, 114 of the rear portion 104. It will be understood that the bar formation provides the rear part 100 of the insole with additional rigidity and resistance to flexure.

As in the first embodiment the premoulded rear part 100 of the insole is shaped to conform to the shape of the last which wilt subsequently be used during manufacture of the shoe. It is connected by adhesive to a front insole part (not illustrated) which may be similar to the front part 14 of the first embodiment, with the resultant, assembled insole then being taken to the last for incorporation in a shoe as described previously.

Also as in the first embodiment, the thickness of the rear portion 104 of the rear part 100 is such as to render it substantially rigid throughout relative to the front part, in this case with the bar formation 06 providing extra rigidity to the rear portion. The thickness of this portion may again diminish progressively in the forward direction. One important advantage of the illustrated insoles and the manner in which they are made, as described above, is that there is no separate shank. Instead, the required rigidity at the rear of the insole is provided by the relatively rigid nature of the rear portion 12.3, 104 of the rear part 2, 100 and the required flexibility in the midfoot region is facilitated by the reduced thickness of the rear part in this region. It is expected that the absence of a separate shank and the choice of a one-piece, moulded rear part will simplify the insole manufacturing process and contribute to overall cost reduction in the manufacture of a shoe or other item of footwear.

Another important advantage of an tnsole according to the invention is the fact that the rear part of the insole is formed as a one-piece, premoulded plastics component shaped for conformity with the particular last which will be used in the manufacture of the item of footwear in question. The rear part is connected in a simple manner to the front part of the insole. These features also simplify the overall manufacture of the item of footwear and contribute to an overall cost reduction.

In the assembled insole, the front region of the front part, i.e. forwardly of the midfoot region, has a high degree of resilient flexibility as in a conventional insole of thin, moulded fibreboard. It will also be understood that the insoles described above will provide a high degree of rigidity towards the rear, a high degree of resilient flexibility towards the front and an intermediate level of resilient flexibility in the midfoot region.

It will be understood that the terms "forward", "forwardly" and the like are used to designate a direction from heel to toe, that the terms "rearward", "rearwardly" and the like are used to designate the opposite direction, i.e. from toe to heel, and that terms such as "down" are used with reference to the normal orientation of an insole in use. It should also be understood that the term "midfoot" is used to designate a location between the heel and toe of the insole, not necessarily an exact midpoint between heel and toe. Persons skilled in the art will recognize that the region where the midfoot ends of the respective front and rear insole parts overlap one another is at a position close to where the ball of a wearer's foot will locate in use.