GB2348404A

GB2348404A - Composite wheel

Info

Publication number: GB2348404A
Application number: GB9907387A
Authority: GB
Inventors: John Savage
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-03-30
Filing date: 1999-03-30
Publication date: 2000-10-04
Also published as: GB9907387D0

Abstract

The composite wheel has a soft, shock absorbent inner core and a hard outer shell. The hard outer shell would reduce friction between wheel and riding surface allowing skateboarders to slide or skid sideways whilst the soft core would provide a shock absorbent cushioning effect enhancing the smoothness and quietness of the ride.

Description

COMPOSITE WHEEL This invention is potentially a new type of skateboard wheel, although its uses are not necessarily entirely restricted to that -particular activity.

Traditional skateboard wheels consist of a solid cylindrical block of urethane encasing two bearings at the hub which revolve around a fixed axle. This invention is a type of skateboard wheel which incorporates two materials as opposed to one in its main cylindrical body. The core of the wheel which holds the bearings would be a soft urethane (or other suitable material), which is in turn surrounded by a hard urethane (or similar) outer shell at the circumference of the wheel where contact is made with the riding surface.

The early skateboard wheels of the 1970's consisted of soft urethane (around 65 on the durometer). This gave a smooth, silent, comfortable, fast ride due to its shock absorbent properties and allowed the skater to pass over rough, uneven surfaces with limited vibration or danger of wheels jamming against debris. They also-as a result of their softnessgripped the riding surface, preventing the possibility of sideways drift or skidding whilst leaning around corners, These high-grip properties are their drawback in terms of modern skateboarding techniques, a central feature of which is the performance of a trick known as'the slide'. The slide trick involves the skater skidding/sliding/drifting his board sideways or through 180-, 360-or more-~with all wheels still in contact with the ground and is impossible to perform with soft, roadgripping wheels. As a result wheels are now made out of a harder urethane (usually 97 on the durometer) which reduces friction between wheel and riding surface. The problem with this is that hard wheels give a very bumpy, noisy uncomfortable ride over uneven surfaces and the wheels can jam against small objects/debris, bringing the skateboard to an instant halt with unpleasant consequences for the rider.

The object of this invention is to give the modern skateboarder the benefit of a smoother, quieter, faster, safer ride whilst allowing himvher to perform modern slide type tricks.

The riding experience of the skateboarder will be enhanced by the cushioning, shock absorbent effect of the soft inner core of the wheel whilst its hard outer shell would reduce grip between wheel and riding surface and allow the skater to slide or skid sideways.

With regard to materials, it is likely (though not certain) that the hard outer shell will be made of a similar material to the standard high quality urethane which is currently in use. but there is no reason why the soft inner core should be materially restricted in the same way. Tho only definite requirements for the soft core are that Ft besoft and springy, with ela. stic properties which return it to its original form and that it does not deform excessively under normal weight conditions as this would lower the axle to a point below the centre of the wheel and reduce speed. Further options and possibilities such as holes or gas bubbles in the soft core can be developed through experimentation. Wheels could also be made with variable degrees of softness in the core tocorrespond to the skater's weight.

Though relevant these considerations do not impinge on the central tenet of the idea which is that the inner core of the wheel is soft and its outer riding surface is hard.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 shows a side and perspective view of the composite wheel.

Figure 2 is a cross section through the composite wheel viewed from the front or back.

It illustrates a suggested cross-sectional shape of the hard outer shell which would prevent it from being forced off the core of the wheel by sideways friction.

Figure 1 shows that the wheel contains a soft inner core (1) which surrounds the bearings fitted at the hub, and that the soft inner core is surrounded by a hard outer shell at the riding surface (2).

Figure 2 suggests that the hard outer shell could be shaped with lips (3) so that it hugs the soft inner core and cannot be forced off by sideways friction. There are many alternative approaches which would prevent the hard shell being forced off and this is only one suggested example. It is not a part of the specification which is the simple principle that the core of the wheel consists of a softer material than its outer running surface.

Claims

CLAIMS 1. A composite wheel with a core consisting of a relatively soft, shock-absorbent material which is encased by a relatively hard shell upon which contact with the riding surface will be made.