Wheel structure

Abstract

A wheel which comprises a hub having an axle receiving aperture, a first portion extending circumferentially about the hub, a second portion extending circumferentially about the first portion, the second portion having a hardness less than the hardness of the first portion, and the second portion forming at least a major percentage of the surface contacting area. The wheel is suitable for use on trolleys and the like wherein it is desirable to have a relatively soft portion when the trolley is stationary to thereby provide stability while, at the same time, providing an easy rolling capability.

Description

FIELD OF THE INVENTION

The present invention relates to a wheel structure and more particularly, relates to a composite wheel structure.

BACKGROUND OF THE INVENTION

The use of composite wheels wherein there are provided two different materials forming the same wheel, each for a desired end, is known in the art. Primarily such wheels have been used for inline skates wherein a harder surface is formed on the center of the blade wherein most of the skating motion occurs while a somewhat softer material is provided about the periphery thereof.

In a number of uses, it is desirable for a wheeled item to be relatively easy to move while, when stopping, providing stability. Thus, one could utilize such a structure on various types of trolleys and the like wherein it would be desirable to have a relatively soft portion when the trolley is stationary and at the same time, providing an easy rolling capability.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a composite wheel which has a combination of properties achieved by using materials having different hardnesses in a composite structure.

According to the present invention, there is provided a wheel comprising a hub having an axle receiving aperture, a first portion extending circumferentially about the hub, the first portion having a first hardness, a second portion extending circumferentially about the first portion, the second portion having a second hardness, the second portion forming at least a major percentage of a surface contacting area, the arrangement being such that the second hardness is less than the first hardness.

In a further aspect of the present invention, there is provided an improvement in a wheel having a central hub, the improvement comprising a hub having an axle receiving aperture, a first portion extending circumferentially about the hub, the first portion having a first hardness, a second portion extending circumferentially about the first portion, the second portion having a second hardness, the second portion forming at least a major percentage of a surface contacting area, and the arrangement being such that the second hardness is less than the first hardness.

The wheel will include a central hub which will have an axle receiving aperture extending therethrough as is well known in the art. The hub may be formed of any suitable material including hard plastic materials and/or metallic materials such as aluminum, steel, and alloys thereof.

In a preferred embodiment, the axle has a portion forming a bushing surface although any conventional bearing and/or bushing structure may be utilized depending on the final use of the wheel.

In one particularly preferred embodiment, the hub is formed of an inner segment and an outer segment with a central vertical flange extending therebetween. In other words, the hub will have a cross sectional H-shaped configuration.

A first portion extends circumferentially about the hub and is interlocked therewith. To this end, there may be provided grooves and/or recesses adapted to receive retaining portions of the first portion.

Extending circumferentially about the first portion is a second portion which forms a primary substrate contacting surface of the wheel. In other words, the second portion is located centrally of the outer surface of the wheel and constitutes at least 50% of the contacting surface thereof.

The second portion is of a softer material than the first portion and therefore has a lower hardness. It may conveniently be formed of a material such as polyurethane.

In the preferred embodiment, the first portion has a hardness of at least 70 D while the second portion has a hardness of between 80 A and 87 A.

BRIEF DESCRIPTION OF THE DRAWINGS

Having thus generally described the invention, reference will be made to the accompanying drawings illustrating an embodiment thereof, in which:

FIG. 1 is a perspective view of a wheel according to the present invention;

FIG. 2 is a side elevation al view thereof;

FIG. 3 is a cross sectional view taken along the lines 3-3 of FIG. 2;

FIG. 4 is a sectional view taken along the lines 4-4 of FIG. 3; and

FIG. 5 is a perspective cut-away view of the wheel structure.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings in greater detail and by reference characters thereto, there is illustrated in FIG. 1 a wheel which is generally designated by reference numeral 10.

Wheel 10, as may be best seen in cross section in FIG. 3, has a hub forming member generally designated by reference numeral 12. Hub 12 has a first inner segment 15 on which there is provided a bushing portion 14. Extending outwardly from inner segment 15 is a vertical central flange 16 and which terminates in an outer segment 18.

Hub 12 also includes a first portion 20 which extends circumferentially outwardly from outer segment 18 and which has sidewalls 22, 24 which are arcuate and meet at a circumferential wall 26. Outer segment 18 has a plurality of recesses therein including a first sidewall recess 28 and a second sidewall recess 30. There is also a top wall recess 32.

As may be seen in FIGS. 3 and 5, a plurality of channels 34 extend through first portion 20 from sidewall 22 through sidewall 24.

Mounted on top of first portion 20 is a second portion which is generally designated by reference numeral 36 and which extends circumferentially along circumferential wall 26 of first portion 20. As may clearly be seen in FIG. 3, second portion 36 has an outer wall 38 which is arcuate in configuration. Outer wall 38 forms at least a major portion of the substrate contacting surface. As will be appreciated, the sizing and relationship of second portion 36 will determine the amount of substrate contacting surface that it forms.

It will be understood that the above described embodiment is for purposes of illustration only and that changes and modifications may be made thereto without departing from the spirit and scope of the invention.

Claims

1. A wheel comprising:

a hub having an axle receiving aperture;

a first portion extending circumferentially about said hub, said first portion having a first hardness;

a second portion extending circumferentially about said first portion, said second portion having a second hardness, said second portion forming at least a major percentage of a surface contacting area; and

the arrangement being such that said second hardness is less than said first hardness.

2. The wheel of claim 1 wherein said first portion has a hardness of at least 70 D.

3. The wheel of claim 2 wherein said second portion has a hardness of between 80 A and 87 A.

4. The wheel of claim 3 wherein said hub is formed of a metallic material.

5. The wheel of claim 4 wherein said metallic material is aluminum.

6. The wheel of claim 4 wherein said first portion is formed of a plastic material.

7. The wheel of claim 6 wherein said second portion is formed of a polyurethane material.

8. In a vehicle having wheels thereon, the improvement wherein at least one of said wheels comprises:

a hub having an axle receiving aperture;

a first portion extending circumferentially about said hub, said first portion having a first hardness;

a second portion extending circumferentially about said first portion, said second portion having a second hardness, said second portion forming at least a major percentage of a surface contacting area; and

the arrangement being such that said second hardness is less than said first hardness.