MULTIPURPOSE BOOT

Abstract

Footwear comprising a foot-fitting portion with a rear portion (1a), a base (2) fitted under the rear portion of the foot-fitting portion, a heel (3) that is releasably fastened to the base (2) by close-fitting assembly means (4, 16, 2a, 3a), and means (5, 7, 17) for automatic locking and manual unlocking of said assembly means, wherein the base (2) is a thin plate of plastics material having at least three tapped metal inserts (nuts) (11, 12) for receiving three fastener screws (14, 15) for fastening the base (2) under the rear portion (1a) of the foot-fitting portion of the footwear.

Description

The present invention relates to the field of footwear. More precisely, footwear of the invention possesses means for receiving either a plurality of interchangeable heels, or else a member for rehabilitation purposes.

BACKGROUND OF THE INVENTION

In the field of footwear, there exists a demand to be able to change the appearance of a piece of footwear, in particular women's footwear, with the possibility of changing the shape or the material or the color of the heel of the footwear while retaining the same foot-fitting portion. Furthermore, certain kinds of footwear may constitute instruments for training or rehabilitation by providing the user's heel with different kinds of bearing on the ground, depending on whether it is necessary to work on balance, ankle strength, bearing of the foot on the ground, . . . .

Proposals have already been made for many years for a removable heel to provide an interchangeability option, but without that culminating in a commercially satisfactory solution. The means that make interchangeability possible have always been complicated, and implementing them often requires recourse to tooling that the user does not master thoroughly. When the heel can be assembled and removed by hand, the quality of the connection is not sufficient to ensure that the footwear can be used safely. Finally, under other circumstances, the materials used do not present sufficient strength to enable prolonged use of the footwear.

Those known means are also unsatisfactory concerning footwear that has a technical function and that is stressed in a manner that is even more severe than ordinary footwear.

The present invention seeks to satisfy appropriately the need for an interchangeable heel by providing a structure for the heel and the footwear that receives it that is suitable for withstanding the high forces to which the heel is subjected while the footwear is being worn.

SUMMARY OF THE INVENTION

The present invention provides footwear comprising a foot-fitting portion with a rear portion, a base fitted under the rear portion of the foot-fitting portion, a rear bearing member of the footwear for bearing on the ground that is releasably fastened to the base by close-fitting assembly means, and means for automatic locking and manual unlocking of said assembly means, the footwear being characterized in that the base is a thin plate of plastics material having at least three tapped metal inserts (nuts) for receiving three fastener screws for fastening the base under the rear portion of the foot-fitting portion of the footwear.

It has been found during thorough testing of the strength of such footwear that breakage occurs at the location where the base is fastened to the foot-fitting portion. The prior art proposes ordinary fastening by means of through screws that are found not to be strong enough, given the small thickness of the base that receives them. This small thickness is required for reasons of the appearance of the footwear so that there is no too-visible discontinuity between the heel and the footwear.

In preferred manner, the inserts are as far apart from one another as possible and they are received in regions of extra thickness of the base, outside the assembly means.

The heel includes recesses for housing said regions of extra thickness on being assembled with the base.

The assembly means are constituted by a male dovetail projecting from the base and a female dovetail formed in the heel. The regions of extra thickness having the nuts embedded therein are located outside the male dovetail, and the heel includes corresponding recesses for receiving these regions of extra thickness during mutual engagement and assembly of the two dovetails. The visible peripheral portion of the base can thus continue to be fine.

Other characteristics and advantages of the invention appear from the description given below of an embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWING

Reference is made to the accompanying drawing, in which:

FIG. 1 is a perspective view from beneath of the rear portion of a piece of footwear of the invention; and

FIG. 2 is a section view on plane II-II of FIG. 1, with the heel and the base assembled together.

DETAILED DESCRIPTION OF THE INVENTION

In the figures, the piece of footwear of the invention comprises a foot-fitting portion 1 with the rear portion 1a thereof being shown. At its bottom, this foot-fitting portion comprises, in known manner: an insole; a welt; a filler having a shank mounted thereon; and a sole.

A base 2 is fitted on the bottom and is used as a removable assembly part for a heel 3. At its periphery, the base is a thin plate of synthetic material (e.g. thermoplastic material) and along its longitudinal axis XX, corresponding to the long direction of the footwear, it possesses a tenon 4 in the form of a male dovetail projecting from the free surface 2a of the thin plate. In the center of the tenon, a resilient tongue 5 integrally molded with the tenon is suitable for being resiliently retracted into a housing 6 in the tenon by pushing one end 5a of the tongue down towards the sole, which end 5a projects beyond the tenon towards the toe of the footwear. In its rest position, the visible surface 5b of the tongue 5 lies in the same plane as the visible surface 4a of the dovetail 4. This surface carries a stud 7, which thus projects from the plane when the tongue is at rest and which is retracted beneath the plane when the tongue 5 is pushed down into the housing 6 by acting on the pusher 5a.

Outside the tenon 4, the thin plate includes regions of extra thickness 8, 9, and 10, the first two being situated at the front of the base (front relative to the front of the footwear), on either side of the tenon 4, while the third is situated at the back of the tenon, on the axis thereof.

Each region of extra thickness constitutes a block overmolded on a metal insert 11, 12, or 13 that is constituted by a nut and that is suitable for receiving a screw such as the screws 14 and 15 in FIG. 2.

The heel 3 of the footwear possesses assembly means complementary to those of the base 2. They are constituted by a female dovetail 16, by a recess 17 formed in the base of the dovetail 16, and by recesses 18, 19, and 20 situated outside the female dovetail 16, in a relative layout identical to that of the regions of extra thickness and the tenon of the base 2.

The base is fitted to the foot-fitting portion of the footwear by means of screws 14 and 15 passing through the bottom of the rear portion 1a of the footwear, as shown in FIG. 2. This fastening is particularly stable since the three nuts 11, 12, and 13 are spaced apart from one another. The base is fastened permanently to the footwear. The heel is then slid onto the base along arrow F in FIG. 1. The dovetails engage one in the other until the stud 7 comes into contact with the front edge of the heel. The stud advantageously possesses a slope that serves to avoid blocking the engagement movement, so the movement continues by causing the tongue 5 to be deflected into the inside of the housing 6. At the end of engagement, the stud 7 is received in the recess 17 of the heel by the resilient return of the tongue to its rest position. The heel is then locked on the base. The fastening is a tight-fit because of compression stress that exists on the heel between the sloping flanks of the female dovetail and the top surface 3a of the heel, with the dimensions thereof and the dimensions of the base being arranged to ensure that this assembly prestress occurs. The regions of extra thickness are of dimensions that are smaller than the dimensions of the housings that receive them so that there is no interference between them and the active assembly means.

The above description relates to a town shoe, but the invention is not limited to that kind of shoe. The invention also applies to footwear for performing technical functions such as orthopedic footwear or footwear for sports or medical use. The foot-fitting portion of such footwear is adapted to holding the foot to the function or the exercise for which the footwear is intended, while the rear portion of the foot-fitting portion, fitted with the base as described above, can be fitted with a member that is adapted to the nature of the support that it is desired to obtain (point support by means of a sphere, off-centered support, . . . ).

Claims

1. Footwear (1) comprising a foot-fitting portion with a rear portion (1a), a base (2) fitted under the rear portion of the foot-fitting portion, a rear bearing member (3) of the footwear for bearing on the ground that is releasably fastened to the base (2) by close-fitting assembly means (4, 16, 2a, 3a), and means (5, 5a, 7, 17) for automatic locking and manual unlocking of said assembly means, wherein the base (2) is a thin plate of plastics material having at least three tapped metal inserts (nuts) (11, 12, 13) for receiving three fastener screws (14, 15) for fastening the base (2) under the rear portion (1a) of the foot-fitting portion of the footwear.

2. Footwear according to claim 1, wherein the inserts (11, 12, 13) are as far apart from one another as possible and they are received in regions of extra thickness (8, 9, 10) of the base (2), outside the assembly means (4).

3. Footwear according to claim 2, wherein the bearing member (3) includes recesses (18, 19, 20) for housing said regions of extra thickness when assembled with the base (2).

4. Footwear according to claim 3, wherein the assembly means are constituted by a tenon (4) in the form of a male dovetail projecting from the base (2) and a female dovetail (16) formed in the bearing member (3).

5. Footwear according to claim 4, wherein the regions of extra thickness (8, 9, 10) in which the nuts (11, 12, 13) are embedded are disposed outside the male dovetail (4), while the bearing member (3) includes corresponding recesses (18, 19, 20) for receiving said regions of extra thickness when the two dovetails (4, 16) are mutually engaged and assembled together.