GB2150010A - Shock-absorbing shoe construction - Google Patents

Abstract

A shock-absorbing shoe sole provides adjustably inflated pneumatic support 21 in a cavity 30 at the rear half of the sole, an intermediate portion with a plurality of upwardly opening pockets 26,27,28 and a front portion 25 of low yieldability. The sole with pneumatic bladder 21 is molded to the preformed upper 10. <IMAGE>

Description

SPECIFICATION Shock-absorbing shoe construction Background of the Invention The invention relates to a shock-absorbing shoe construction, particularly applicable to light-weight athletic shoes of the general variety popularly known as sneakers.

Foot comfort for the athlete and for those who jog or walk briskly for general exercise has been the target of many and varied proposals for shoe construction. And the broad concept of using a pneumatic cushion as part of the heel and/or sole construction has been known for the better part of a century, illustratively through King US patent 541,814 of 1895 and Maddocks US patent 1,011,460 of 1911.In more recent years, efforts have been directed to providing substantially uniformly absorbent action along the full length of the foot, either by employing specially fabricated pneumatic sheet material (as in Sindler US patent 2,100,492), or by incorporating a full-length inflatable bladder in the sole (as in Reed US patent 2,677,904 and in Cortina US patent 2,863,230), or by providing an outsole with a substantially uniform distribution of air4illed cavities over the full area of the sole (as in Gardner US patent 4,012,855, Petrosky US patent 4,129,951, Khalsa et al US patent 4,1 33,118, Moss US patent 4, 1 70,078, and Doak US patent 4,397,104), or by providing a tread characterised by a distributed plurality of resilient "posts" served by interconnecting channels and a common source of pneumatic pressure (as in Muller US patent 4,319,412). European patent 0,032,084 and German provisional patent Offenlegungsschrift OS 2,460,034 are illustrative of various arrangements to so construct the sole as to enable pneumatic preloading of all or selected regions of the foot.

These more recent structures are unduly complex, and they do not recognise or provide for the kind of distributed shock-absorbing resilience which is needed for alternating or intermittent jog/walk exercise.

Brief Statement of the Invention It is an object of the invention to provide an improved shoe construction of the character indicated, offering maximum comfort for both jogging and walking modes of use of the same shoe.

A specific object is to provide a shoe construction wherein shock-absorbing pneumatic action is to different degree, as a function of location along the length of the shoe, progressing from near-zero absorbance at the forefoot region, and achieving selectively variable maximum absorbance throughout substantially the rear half of the shoe.

Another specific object is to achieve the above objects with essentially simple structure, lending itself to inexpensive mass-pro action.

The invention achieves the foregoing objects with what amounts to a two-part sole configuration, wherein the first or upper part is the flexible bottom panel of a subassembly with shoe-upper structure, and wherein the second or lower part is molded to characterise the upper layer or lining of the tread of the shoe. The characterising establishes (1) a first zone in the form of a large upwardly open pocket with peripheral sidewalls and an internal wall at substantially the midsection of the shoe, (2) a second or forefoot zone which is essentially void-free and which is offset from the first zone, and (3) an intermediate or transition zone of plural upwardly open pockets, between the first and second zones. An inflatable bladder conforms generally to walls of the large pocket and has valve and tube access through the heel part of the sidewall, for inflation purposes.The flexible bottom panel of the shoe-upper subassembly is bonded to the molded upper layer of the tread to close all pockets.

Detailed Description of the Invention The invention will be described in detail for a preferred embodiment, in conjunction with the accompanying drawings, in which: Fig. 1 is a side view in elevation of a shoe embodying the invention; Fig. 2 is a plan view of a molded component of the sole of the shoe of Fig. 1; Fig. 3 is a fragmentary longitudinal sectional view of the lower region of shoe-upper structure, in readiness for assembly to shoesole structure of Fig. 2; Fig. 4 is a longitudinal sectional view of the sole structure of Fig. 2, taken on the alignment 4-4 of Fig. 2; Figs. 5 and 6 are sectional views, respectively taken at 5-5 and at 6-6 in Fig. 2; and Fig. 7 is a partly broken-away side view of a bladder component of the shoe of Fig. 1.

In Fig. 1. a shoe which illustratively embodies the invention is seen to comprise a lightweight upper 10 of woven synthetic fiber with externally sewn leather or leather-like reinforcements 11 in and around the toe region and at 1 2-1 3 in the heel region; further such reinforcements are provided at 1 4 for lacing eyelets, and at 1 5 to complete the reinforced integrity of the top of the shoe. The sole 1 6 extends the length of the shoe, being thinnest at the forefoot region and rising gradually through the arch to a well-elevated heel region.The sole is characterised (1) by substantially no compliant yieldability. but relatively great flexibility, at the forefoot region, designated A, (2) by maximum compliant yieldability (and essentially no flexibility) throughout substantially the rear half of the shoe, designated B, and (3) by progressively increasing compliant yieldability (and reducing flexibility) in a transition zone C which interconnects regions A and B. A cleated tread 1 7 characterises the underside of sole 16, and a rising peripheral sidewall 1 8 is an integral formation of the sole, throughout regions B and C; in Fig. 4, the cleated underside of the sole is seen to be a feature of a lower ply which extends the full length of the sole and which includes a cap or toe-lapping formation 1 9 secured around the toe of upper 10.Finally, to complete the description of Fig. 1, a pneumatic-inflation fitting 20, which is part of an internally captive elastomeric bladder 21 (see Fig. 7), projects through a limited opening in sidewall 18, at the heel.

In accordance with a feature of the invention, the upper 10 is a subassembly having a bottom-surface layer 22 (see Fig. 3) of elastomeric material. In manufacture of the shoe, layer 22 is bonded to structural contours of the molded elastomeric upper surface or layer 23 of sole 1 6 (see Fig. 4), it being noted that peripheral sidewalls 1 8 are integral formations of the molded layer 23.

More particularly, the molded layer 23 is viewed in plan in Fig. 2 and comprises a thin solid area 25 at the forefoot region A. In approach to intermediate region C, the thickness of area 25 builds for smooth transition to the rising profile of intermediate region C.

Region C is characterised by a cluster of upwardly open generally rectangular pockets 26-27-28 of progressively increasing vertical extent. In the rear zone C, a single large upwardly open pocket 30 is defined by a thin bottom panel 31, by sidewalls 18 rising therefrom, and by the generally central internal wall 32 at which zones B and C are adjacent.

For purposes of well-seated assembly to and support of the shoe-upper subassembly 10, the sidewall section features an integral upper flange 33 which extends inwardly and is preferably further characterised by a short outer rib 34. This flange 33 and rib 34 feature of the sidewall section is shown at the heel (Fig. 4) across the region B of the large pocket 30 (Fig. 6), and across the intermediate region C of clustered pockets (Fig. 5). In other words, the support afforded by flange 33 extends peripherally and continuously through all zones and reduces to zero near the toe end of zone A. The only interruption in continuity of sidewall 1 8 is at the heel, where a local opening 35 and adjacent recess in the web of the sidewall section are configured to receive bladder 21 and its inflation-valve fitting 20.

In preparation for assembly of the shoe of Fig. 1, the upper assembly 10 will first have been completed, to the point of consolidating various lining laminations to the elastomeric bottom layer 22. Specifically, the regions A and C of layer 22 are lined with and bonded to a thin slightly cushioning layer 36 of expanded flexible plastic sheet, such as an expanded urethane, with layer 36 extending forwardly and up around the front of the toe.

Toe protection is further enhanced by another layer 37 of expanded plastic material bonded to and lining the toe region of layer 36; and a relatively thin panel 38 of more stiffly flexible felt or fiber board, with feathered ends and edges, is bonded to layer 36 and is thus laminated to layers 22 and 36 in regions A and C. In addition, a second but substantially thicker panel 39 of stiff and relatively inflexible felt or fiber board, also with feathered ends and edges, is laminated to layer 22 in region B, with feathered-end overlap into region C, and over the feathered end of panel 38. Preferably, the described laminations of the bottom of the upper assembly 10 are peripherally stitched in the feathered-edge areas, to assure retention of all lamination bonding.

Further assembly proceeds by taking the molded elastomeric part 23 and inserting bladder 21 in pocket 30, with the nut of the inflation fitting 20 tightly set to clamp the same across the sidewall opening 35. After first applying a coat of adhesive over the entire exposed bottom surface of layer 22, the upper subassembly is so applied to the molded part 23 that peripheral margins of panel 22 seat securely on flange areas 33, within and located against the peripheral rib 34, it being understood that, at the toe end, flange areas 33 will have merged with the thin surface of the molded part 23, and that in the presence of clamp action to promote full bonding, the panel 22 will also have bonded to upper edges of dividers between pockets 26-27-28, thus sealing off all of these pockets.

Having bonded molded part 23 to the upper subassembly, the tread panel 1 7 of the sole is similarly applied in bonded registry with the smooth underside of part 23. In this connection, it is helpful to inflate bladder 21 while allowing adhesive to cure in a clamped application of tread panel 1 7. At the toe end, tread panel 1 7 is in bonded overlap with the toe end of the upper 10, and a dashed line 40 in Fig. 4 will be understood to designate a region and orientation for riveted fastening of the tip end of tread panel 1 7 to the reinforced toe of upper 1 0.

Detail of the construction of upper 10 has been omitted as being irrelevant to the sole construction of the invention, but a preference is indicated to complete the shoe by insertion of a molded cushion insole, suggested by phantom outline 41 in Fig. 4.

The described shoe construction will be seen to achieve all stated objects. Firm forefoot support is via the region A of greatest importance to the jogger. Progressive compliant yieldability in the intermediate zone assures the jogger against shock other than to the forefoot, even when jogging on uneven or gravelly surfaces. On the other hand, the energetic walker can adjust the shock-resisting and support properties of the region B to suit his comfort and style, and the progressive cluster of sealed pockets 26-27-28 in zone C provides a comfortable transition of compliant support, down to the firm-footed feeling which derives from minimum cushioning of forefoot support. The relative inflexibility of plate 39, which fully spans region B and receives direct load-bearing support from inner wall 32, assures against any "mushy" feeling or action within region B. Finally, the inwardly canted nature of sidewalls 18, as best seen in Fig. 6, contributes to the firmfooted feel of the shoe, in that sidewall deflection under load is characterised by a laterally inward thrust from both sides, thus contributing to foot-positioning stability.

Although the invention has been described in detail for a preferred embodiment, it will be understood that modifications may be made without departing from the scope of the invention.

Claims (7)

1. A shoe having a sole characterised by a first or forefoot region of relatively low compliant yieldability, a second or heel region of relatively great compliant yieldability, and a transitional intermediate region between said first and second regions; said heel region comprising a single pocket defined (1) by flexible upper and lower panels extending for substantially the rear half of the sole and (2) by peripheral sidewalls including an internal wall at juncture with said intermediate region, an inflatable bladder retained within said pocket and conforming generally to adjacent surfaces of said walls and panels, said bladder having an inflation device including a check valve projecting for external access through one of said sidewalls; said forefoot region comprising stiffly flexible and relatively voidfree material; and said intermediate region comprising a distributed cluster of sealed pockets,

2. The shoe of claim 1, in which a stiffly compliant plate secured to and over the area of said upper wall extends forward into at least partial overlap with said intermediate region.

3. The shoe of claim 1, in which the sealedpocket region is characterised by progressively increasing compliant yieldability in the direction of approach to said internal wall.

4. The shoe of clam 1, including a shoe upper secured to said sole; said sole comprising a first elastomeric part in the form of a smooth bottom-surface panel of the shoe upper and united thereto as a subassembly; said sole further comprising a molded elastomeric lower part having a continuous bottom and a characterised upper surface which 11) is relatively thin and compressionally non-compliant in said first region, (2) integrally includes said peripheral sidewalls upstanding from the continuous bottom, said walls extending peripherally at least around the second and intermediate regions, with -faired merger into the bottom at said first region, and (3) comprises a plurality of upwardly open pockets within said intermediate region; said bottom-surface panel of the shoe upper being bonded to the characterised upper surface of said molded lower part in all said regions to close said pockets.

5. The shoe of claim 4, in which said molded part has a smooth lower surface, and in which a molded tread panel with a smooth upper surface is bonded to said smooth lower surface.

6. The shoe of claim 4, in which the depth of said upwardly open pockets increases progressively throughout said intermediate zone in the direction toward said heel region.

7. A shoe, or a sole for a shoe, substantially as hereinbefore described with reference to the accompanying drawings.