Footwear

Abstract

A heel supporting member for inclusion in footwear comprises a heel supporting plate having a front edge adapted for location intermediate the ends of the article of footwear, and a wire suspension located on and attached to the underside of the plate, the wire suspension being adapted to yield under the action of forces applied to it by the plate when the latter is loaded, and comprising at least three curved portions connecting the plate supporting sections and the sections adapted to rest on the heel of an article of footwear, which sections are at an incline to each other and form an apex along the curved connecting portions that are arranged in a transverse line towards the front edge.

Description

THIS INVENTION relates to shoes, boots and like articles of footwear of the type including a resiliently mounted heel support therein for absorbing the mechanical shock normally transmitted to a wearer's heel.

It has been proposed that in order to make footwear more comfortable, a resiliently mounted heel supporting member be located over the heel portion thereof thereby providing means for absorbing mechanical shocks which would normally be transmitted to the heel of a person wearing such footwear.

In an arrangement disclosed in our South African Pat. No. 70/1162 a heel supporting plate is formed from a single sheet of resilient steel which is bent over to provide two limbs that subtend between them an acute angle. One limb rests on the heel of a shoe or like article of footwear while the other limb provides support for the heel of a wearer. During walking, flexing of the plate occurs at its apex which leads to greater walking comfort.

A disadvantage of such arrangement is that the regular flexing during walking causes metal fatigue to set in and the eventual fracture of the plate along its apex

In a further arrangement which has been proposed a heel supporting member comprises a heel supporting plate and a wire suspension which yields under torsional forces when a load is applied thereto. The wire suspension is made of spring steel wire and is bent into two U-shaped portions which are formed either from separate lengths of wire or a single length. The adjacent arms of the two U-shaped portions are inclined away from the remaining wire sections and are adapted to rest on the heel portion of a shoe or the like. The supporting plate is attached to the remaining wire sections and torsional forces occur in the curved part of the U-shaped members of the wire suspension adjacent the apex of the heel support to absorb mechanical shocks encountered during walking or running.

The physical dimensions allowed to the heel supporting member require each curved part of the U-shaped members of the wire suspension to conform to a certain radius of curvature. Each curved part comprises a single portion of spring steel wire, which must be of sufficient thickness or diameter to withstand the average load placed on the heel support. When spring steel wire of this thickness is bent to form a curved member conforming to the physical dimension required, the wire is generally weakened and must be heat treated, in order to give the wire suspension the required strength and resilience.

Furthermore, it is usual in the manufacture of footwear to locate inside a shoe or the like and over the heel portion, an insert conforming in shape and dimension to the rear portion of the shoe. This insert is often made of plastics or other suitable material and is commonly known in the art as a shank. The purpose of the shank is to effectively raise the level of the inner surface of the shoe to the level of the inwardly curved lower edges of the upper foot enclosing portion of the shoe.

It is accordingly the object of the present invention to provide a heel supporting member comprising a supporting plate and a wire suspension wherein the wire does not require heat treatment to improve its strength and resilience and to provide an article of footwear in which the heel supporting member is securely located.

In accordance with the present invention there is provided a heel supporting member for inclusion in an article of footwear comprising a heel supporting plate having a front edge adapted for location intermediate the ends of the article of footwear and a wire suspension located on and attached to the underside of the plate, the wire suspension being adapted to yield under the action of forces applied to it by the plate when the latter is loaded and comprising at least three curved portions connecting the plate supporting sections and the other sections adapted to rest on the heel of an article of footwear, which sections are at an incline to each other and form an apex along the curved connecting portions that are arranged in a transverse line towards the front edge.

The term `wire` is used in this specification in a broad sense to cover an elongated member having either a rounded or polygonal cross-section. Preferably it is drawn from spring steel.

Further features of the invention provide for the heel supporting plate to be dish-shaped to substantially conform to the shape of the underside of a heel and for the wire suspension either to comprise a single serpentine length of looped wire with the alternate loops being inclined to the supporting plate or to comprise at least two curved basically W-shaped wires which lie adjacent along at least part of their lengths and wherein the central curved portions of the W-shapes are inclined to the heel supporting plate.

A still further feature of the invention allows for those sections of the wire suspension adapted to rest on the heel of the article of footwear to be attached to a plate optionally conforming to the shape of the heel of the article.

The invention also provides an article of footwear, the improvement which comprises a shank having a recess shaped to receive and locate therein, at least some of those sections of a wire suspension located on the underside of the heel supporting plate of a heel supporting member which are inclined away from the plate.

Further features of this aspect of the invention provide for the heel support member to be of the type defined above in which case the recess of the shank is adapted to accommodate at least one U-shaped section of the wire, for the shank to be made of plastics or other suitable material and to be optionally shaped to form a support for the arch of a foot and for the periphery of the shank to be flanged or chamfered.

Preferred embodiments of the invention will now be described by way of example, reference being made to the accompanying drawings in which:

FIG. 1 is an inverted plan view of one form of a heel supporting member according to this invention;

FIG. 2 is a sectional view along II--II in FIG. 1;

FIGS. 3, 4, and 5 are inverted plan views of alternative heel supporting members;

FIG. 6 is a cross-sectional side elevation of a shoe fitted with a shank and a heel supporting member according to this invention;

FIG. 7 is a plan view of the shank included in the shoe shown in FIG. 6; and

FIG. 8 is a cross-sectional side elevation of an alternative shank.

In the embodiments of the invention shown in FIGS. 1 to 5, a heel supporting plate 1 is mounted on a wire suspension. The heel plate 1 conforms in shape to the heel portion of a shoe so that when located in position in the shoe, the shoe wearer's heel rests comfortably on the plate.

In one form of the invention shown in FIGS. 1 and 2 the wire suspension is formed from a pair of basically W-shaped curved wires 4 and 5. The arms of the one W-shaped wire 4 extend around the periphery of a heel shaped plate 1 and may join to form one continuous length. The arms of the other W-shaped wire 5 do not join, and these arms and those of the first wire member are fixed to the heel plate 1 by means of two lips 6 forming part of the heel plate which are bent around the arms of the two wire members. A further lip 8 secures the integral wire member 4 to the curved rear edge of the heel plate 1.

The internal U-shaped section 7 of each wire member is bent away from the heel plate 1 and is inclined to the underside of the plate, meeting it near its front substantially straight edge 11. In use these internal U-shaped sections rest on the heel of a shoe so that when a load is applied to the plate, as by the weight of a person, the plate supporting sections of the wire members will be urged toward the inclined sections 7 of these members. A resilient torsional force on the four curved portions 4A and 5A will dampen any shocks transmitted from the heel as during walking or running and such activities will therefore be more comfortable with the use of such an arrangement.

It is to be appreciated that the torsional force is shared by four curved portions 4a and 5a and this fact allows the thickness of the spring steel wire used to be less than that generally used at present and furthermore, it has been found that no treatment of these portions is necessary to ensure that they have sufficient torsional strength.

An alternative form of the invention is shown in FIG. 3. In this case the wire suspension comprises a serpentine length of looped steel spring wire 9. Alternate loops are bent so that they are inclined to the heel plate 1 and the intermediate loops abut and support the heel plate 1. The external arms of this wire member are attached to the plate by bent lips 6 in a similar manner to that described above. Additional fingers 10 project from the underside of the heel plate and secure the heel plate supporting sections of the wire member thereto.

In this case, it is to be noted that six curved portions will share the torsional force that is exerted thereon during use and this results in the fact that even thinner spring steel wire may be used in this embodiment than in the first case.

In use, the heel supporting member is located in a position over the heel portion of the shoe to rest upwardly and rearwardly from the leading edge 11 thereof. The heel supporting member may be secured to the shoe in any convenient manner, but is preferably secured as outlined below.

Alternative forms of the supporting member according to this invention are shown in FIG. 4 and 5 and components thereof equivalent to components outlined above are similarly numbered.

In both these cases, the arms of the W-shaped wire 4 do not meet but are bent so as to provide additional strength and resilience to the members.

As shown in FIG. 4, the end portions of the wire 4 adjacent the rounded part of the heel supporting plate curve inwardly toward the centre of the plate and then outwardly. In addition, each end portion curves away from the plate such that it forms part of a helix 12 with the end being furthest from the plate.

It is to be appreciated that such an arrangement in use, provides additional resilience to the wire suspension since when a load is applied to the plate, the part-helices 12 will contact an inner sole located thereunder which will in turn contact the portions 7 of the wires and absorb some of the mechanical shock transmitted from the heel. At the same time, the torsional stresses experienced by the portions 4a and 5a of the wires will be correspondingly reduced with the result that even thinner wire than in the cases above, may be utilised to manufacture such a supporting member.

The arrangement shown in FIG. 5 serves a similar purpose but in this case the end portions 13 of the W-shaped wire 4 project directly toward the centre of the plate 1 and are inclined away from the plate. Thus, the part-helices of the embodiment shown in FIG. 4 are obviated but the end portions 13 are still capable, in use, of absorbing part of the mechanical shock transmitted from a shoe heel.

A preferred member of which a heel supporting member according to this invention is included in an article of footwear is now outlined. As shown in FIGS. 6 and 7 a heel supporting member similar to that shown in FIG. 1 is located over the heel 22 of a shoe 21.

The portions 7 of the wires 4 and 5 rest on a shank 26 recessed in the heel portion thereof as at 27 to accomodate these portions. This is clearly shown in FIG. 7 where the wire is represented by dotted lines. It will be appreciated that the wire will be located in the shank 26 by the recess 27 and thereby maintained in position.

The shank 26 may be curved on its upper surface to form simultaneously an arch support in the shoe. Further the shank can be conveniently and inexpensively made of plastics material or a combination of plastics material, and for instance, canvass material.

A shoe manufactured in the usual and known manner by securing the outer sole 30 to the upper 31 and to a heel 32. The shank is then fitted in the shoe to even out the step formed by the bent over edge 36 of the upper. An inner sole 33 is then located over the shank. This inner sole has a transverse slot 34 therein to allow the portions 7 of the wires 4 and 5 to be passed therethrough and located in the recess 27. A lining 35 over the inner sole and the heel support plate 1 conceals the heel support member.

As is usual, the width of the shank is smaller than that of the inner sole. However, in certain applications and particularly where the shank is to be used in vulcanised shoes, the width of the shank may be the same as that of the inner sole. This enables the shank to be rigidly secured to the inner sole when the shoe is vulcanised. In this application the periphery of the shank is preferably chamfered to produce a bevelled edge around the shank or stepped as shown in FIG. 6 to form a flange around the periphery thereof. As shown, the flange rests on the bent over edge 36 of the upper in use. To facilitate the security of the shank in the shoe, at least the periphery of the shank is preferably of canvass material which allows a good bonding action with an adhesive.

An alternative shank is shown in FIG. 8 where the recess 27 for the wire is a passage through the heel portion of the shank. The passage is shaped to receive the U-shaped sections 7 of the wire therein and thereby retain the heel support member in position.

Obviously other embodiments to those outlined above are possible within the scope of the invention, both with regard to the heel supporting member and the shank. Various alternate forms of wire may be employed in the manufacture of the wire suspension. Thus, instead of using wire of rounded cross-section, wire drawn or rolled to a rectangular or other cross-section may be employed.

It will be appreciated that by means of the shanks as above described, the heel support member need not be secured to the shoe and the member will always be retained in position. Furthermore the manufacture of an article of footwear embodying a support member and a shank as above described may be effected using conventional footwear making machinery. No specialized machinery is required.

Claims

What I claim as new and desire to secure by Letters Patent is:

1. A heel supporting member for inclusion in an article of footwear comprising a heel supporting plate having a front edge adapted for location intermediate the ends of the article of footwear and a wire suspension located on and attached to the underside of the plate, the wire suspension being adapted to yield under the action of forces applied to it by the plate when the latter is loaded, and comprising a serpentine length of looped wire with alternate loops being inclined to said heel supporting plate and adapted to rest on the heel of an article of footwear, and intermediate loops abutting and supporting said plate.

2. A heel supporting member as claimed in claim 1 in which the heel supporting plate is dish-shaped to approximately conform to the shape of the underside of a heel.

3. A heel supporting member as claimed in claim 1 in which there are at least six intermediate loops of the wire suspension for support of said plate.

4. A heel supporting member for inclusion in an article of footwear comprising a heel supporting plate and a wire suspension located on and attached to the underside of the plate, the wire suspension being adapted to yield under the action of forces applied to it by the plate when the latter is loaded, and comprising at least two basically W-shaped curved wires which lie adjacent along at least part of their lengths and wherein the central curved portions of W-shaped wires are inclined to the heel supporting plate connecting sections of the wire suspension supporting said plate and other sections of the wire suspension adapted to rest on the heel of the article of footwear, which sections are at an incline to each other and form an apex along the curved connecting portions.

5. A heel supporting member for inclusion in an article of footwear comprising a heel supporting plate and a wire suspension located on and attached to the underside of the plate by means of lips provided at the periphery of the plate and bent under and around the adjacent parts of the plate supporting sections of wire, the wire suspension being adapted to yield under the action of forces applied to it by the plate when the latter is loaded, and comprising at least three curved portions connecting sections of the wire suspension supporting said plate and other sections of the wire suspension adapted to rest on the heel of the article of footwear, which sections are at an incline to each other and form an apex along the curved connecting portions.

6. In an article of footwear, a heel supporting member comprising a heel supporting plate having a front edge adapted for location intermediate the ends of the article of footwear and a wire suspension located on and attached to the underside of the plate, the wire suspension being adapted to yield under the action of forces applied to it by the plate when the latter is loaded, and comprising at least three curved portions connecting sections supporting said plate and other sections adapted to rest on the heel of the article of footwear, which sections are at incline to each other and form an apex along the curved connecting portions that are arranged in a transverse line towards said front edge; and a shank having flanged peripheral edges to ensure proper placement and rigid securement of said shank in the article of footwear and a recess shaped to receive and locate therein, at least some of those sections of the wire suspension which are inclined away from the heel supporting plate.

7. A heel supporting member as claimed in claim 4 in which the outer arms of at least one of the W-shaped wires extend around the periphery of the rear portion of the heel supporting plate and are joined at their ends.

8. A heel supporting member as claimed in claim 4 in which the outer arms of at least one of the W-shaped wires extend around part of the periphery of the rear portion of the heel supporting plate and then project toward the centre of the plate between the plate and said central curved portion of the W-shaped wire and with the centrally projecting portions of the outer arms being inclined to the plate.

9. A heel supporting member as claimed in claim 4 in which the outer arms of at least one of the W-shaped wires extend around part of the periphery of the rear portion of the heel supporting plate and then project toward the center of the plate and toward the side edges of the plate when viewed in plan view and are inclined to the plate to form part helices.

10. The article of footwear as defined in claim 6 in which the recess of the shank is a passage formed longitudinally in the heel portion of the shank.

11. In an article of footwear defined in claim 6 having an inner and outer sole between which the shank is located and the heel supporting member located above the inner sole, the inner sole being provided with a slot therein to allow passage of the inclined sections of the wire suspension of the heel supporting member therethrough.