SPORTS FOOTWEAR
This invention relates to sports footwear, and in particular to sports boots and shoes having studs on the soles thereof.
Sports boots and shoes having studs on the soles thereof are well known and are used in various sporting activities. In particular, players of soccer, rugby union and rugby league wear such boots. Athletes, particularly those running in cross-country events, and cyclo-cross cyclists wear such shoes. In some cases, the studs are moulded integrally with the outsole of the boot or shoe. Alternatively, in order that worn studs can be replaced or the footwear can be adapted for differing surfaces, new or different studs may be screwed into a stud receiving housing retained in the outsole of the footwear. In all such cases, when running over very soft surfaces, the studs penetrate the surface and provide traction and stability for the runner. However, if the surface being run over is hard, the studs are subjected to shock loading that is transmitted to the outsole and thence to the feet and legs, creating discomfort for and even injury to the runner. To a certain extent, these problems may be counteracted by the use of the differing studs and by having soft and resilient inner soles in the footwear. However, such means has not entirely overcome the problems referred to above, particularly if the type of surface on which the footwear is used varies over the course of an event.
It is an object of the present invention to provide studded footwear, the use of which overcomes to an appreciable extent, the problems encountered by use of known footwear.
The invention provides sports footwear with an outsole having a stud receiving housing retained therein, a stud received in the housing, and having resilient means disposed between the stud and the outsole.
The footwear may also comprise resilient means disposed between the stud and the housing.
The resilient means disposed between the stud and the outsole may comprise a spring washer and/or may comprise a washer of an elastomer. The washer may be bonded to the stud.
The resilient means between the stud and the housing may comprise a bush, which may be of a polymer such as polyurethane. The bush may have a female screw thread therein. Alternatively, the housing may have a female screw thread therein. In either case, the footwear may comprise a male screw adapted to secure the stud in the bush or housing. The male
screw may pass through a central bore of the stud, and the washer and the outsole may have co-operating locking means whereby relative rotation between them is resisted.
The housing may be of polymer, aluminium alloy or steel, and the latter may be carbon spring steel. In the case of a housing of polymer, the housing may have a threaded steel insert therein.
The footwear may comprise an insole. Further resilient means may be disposed between the insole and the housing. The further resilient means may comprise a pad of an elastomer. Alternatively, the housing may have the further resilient means in the base thereof, in which case the further resilient means may comprise a compressible cavity therein.
The invention will now be described with reference to the accompanying drawings in which: Fig. 1 is a sectional elevation of a first embodiment, Fig. 2 is a sectional elevation of a second embodiment, Fig. 3 is a sectional elevation of a third embodiment, and Fig. 3 is a sectional elevation of a fourth embodiment.
Referring now to Fig. 1, there is shown part of footwear 10 in the form of a boot or shoe. The footwear 10 has an outsole 11 and an insole 12. Secured by pressing, moulding or bonding in the outsole 11 is a housing 13 of a polymer, aluminium alloy or steel. Located in the housing 13, from within the footwear 10 whilst the insole 12 is temporarily removed, is a bush 14 of a polymer, e.g. polyurethane. The larger inside diameter of the housing 13 and the top outside diameter of the bush 14 are splined to resist relative rotation when fitting or removing the stud 15. The stud 15 is of polymer or aluminium alloy, and has a resilient washer 16 bonded to its base. The resilient washer 16 is of an elastomer, having a soft, medium or hard resilience, or is a spring washer of such material. The washer 16 has a bore 18 that fits over the part of the bush 14 protruding from the outsole 11. The bore 17 of the bush 14 has a female thread to receive a screw 18 that passes through a bore 20 of the stud 15. This retains the stud 15 on the footwear 10 with the washer 15 disposed between the stud 15 and the outsole 11. Studs 15 of differing materials and lengths may be fitted at the wearer's choice dependent on the surface on which the footwear 10 is to be used. The length of the bush 14 and the thickness of the washer 16 are chosen so that the stud 19 "bottoms out" on the bush 14 with the wasfrer 16 under slight compression, thereby creating a sealed assembly to repel the ingress of water. This also maintains the bush 14 in the housing 13. An optional elastomer part 21 may be fitted in the housing 13 below the bush 14 to add stability to the assembly when it is compressed and
aid the recoil action. Alternatively, an internally threaded aluminium alloy or steel insert 22 may be fitted inside the bush 14 to receive the screw 19 instead of the bush 14 being threaded.
On impact of the stud 15 with firmer surfaces, the washer 16 will absorb at least a significant amount of the shock loading and prevent this being transmitted to the outsole 12. Additionally the bush 14 compressing into the space beneath it or together with the part 21 if fitted, will absorb some of that shock loading. In consequence, the shock loading will not be transmitted through the insole 11 to the foot of the wearer.
Referring now to Figs. 2 to 4, there are shown other embodiments of footwear 25 of generally similar construction to that of Fig. 1. However, in these cases, the housing 26 is manufactured from a carbon spring steel or polymer. A 5mm female threaded part 27, which receives the screw 28 that secures the stud 29, is manufactured integrally with either a 25-30mm O/D spring disk or is retained within the housing 26 of moulded polymer. The housing 26 is bonded or over moulded into the top of the outsole 30, on its outside diameter only, and is visible when the tunable insole 31 is temporarily removed. Once assembled, the housing 26 becomes an integral part of the outsole 30 and is the pivot point from which the assembly operates.
Another steel/polymer insert 32 is bonded or moulded into the outsole 30 where the housing 26 projects through. A thin polymer bush 34 is then fitted over the housing 26 into the cavity between the housing 26 and the insert 32 prior to stud assembly. This will take up any wear between the moving components over time and is replaceable. The washer 35 and the outsole 30 have co-operating formations 33a, 33b to resist relative rotation when fitting or removing the stud 28.
This arrangement enables the outside diameter of the housing/bush combination 26/34 to be between 8mm-12mm, recessing into the stud 29 through the elastomer washer 35. This construction significantly improves the assembly's ability to deal with potential lateral forces acting upon it in use. A choice of soft, medium or hard compound elastomer washer 35 is over molded and bonded to colour coded studs 29. Different stud colours represent a different density of elastomer used. A choice of compounds enables the wearer to tailor-make the shoe to suit their own requirements (running styles), or ground conditions. The stud 29 would also be available in two lengths to provide more variants to the shoe's set up. The stud 29 is then secured to the shoe 25 via a traditional 5mm-screw 28.
The length of both the housing 26 and polymer bush 34, along with the thickness of the elastomer washer 29, are chosen so that when the housing 26/bush 34 bottoms out within a
recess 36 in the stud 29, the elastomer washer 35 is pre-compressed. This also creates a mechanically sealed assembly, preventing both water and dirt ingress, whilst retaining the housing 26 firmly within the outsole 30 due to the pre-load on the elastomer washer 35.
Once all stud assemblies have been secured, a choice of insole 31 is placed back into the shoe 25, which is then is ready to wear. Insoles 31, like the washers 35, can be produced in different densities of polyurethane or other suitable material, either as a whole (Fig 2, insole 31) or with elastomer pads 37 individually located above the housings 26 (Fig 3, insole 38). Alternatively, air technology may be utilised to produce tunable options (Fig 4, compressible air space 39 within the housing 40). Such constructions enable the wearer to build a truly bespoke pair of sports footwear.
When worn on good soft ground conditions, the stud 15, 29 will penetrate to its full depth. Should the stud 15, 29 meet any resistance within a firmer playing surface, the washer 16, 35 will absorb initial peak pressures to the sole of the foot at that point. Energy/shock is absorbed throughout the entire outsole unit 11, 30, via the chosen elastomer washer 16, 35 on the stud 15, 29, the housing 13, 26 and the chosen tunable insole 12, 31. On compression, the effective length of the stud 15, 29 is reduced, whereby the outsole 11 , 30 of the footwear 10, 25 now has a greater opportunity to make contact with the ground. This in turn helps to distribute the wearer's weight more evenly across the sole of the foot. The greater the outside diameter of the housing 13, 26 set into the outsole 11, 30, the greater the displacement of energy across the sole of the foot.
All component parts, (excluding the housing 13, 26) are replaceable, creating a new market for tunable spare part options. The invention provides a simple construction that remains lightweight. The invention provides an arrangement that reduces peak pressures to the sole of the foot at that point on impact. This in turn helps to reduce potential soft tissue damage and associated injuries such as Planter Fascititis. It also provides additional comfort, when married with tunable insoles 12, 31, whereby the wearer can sustain a higher level of performance for a longer period.
Other embodiments of sports footwear in accordance with the invention will be readily apparent to persons skilled in the art. For example, the screw 19 may be integral with the stud 15. The resilient washer 16, 35 could comprise a compressible air space similar to the air space 39 within housing 40 of the Fig 4 embodiment.