Granted Patent B2

US 9,527,163 · App. 14/527,538 · Granted Dec 27, 2016

Abstract

Claims (27)

1. An apparatus, comprising:

a first axle extending from a left side support to a right side support, the first axle configured to axially rotate;

a second axle extending from the left side support to the right side support and being substantially parallel to the first axle, the second axle configured to axially rotate, the second axle and the first axle being spaced apart;

wherein each of the first axle and second axle comprising:

two or more lower support wheel assemblies and two or more higher support wheel assemblies alternatingly positioned along each axle,

wherein the higher support wheel assemblies have a larger diameter than the lower support wheel assemblies, and

wherein each of the lower support wheel assemblies and the higher support wheel assemblies are configured to axially rotate with a corresponding axle.

2. The apparatus of claim 1 , wherein a spacing between a lower support wheel assembly and an adjacent higher support wheel assembly on each axle is adjustable.

3. The apparatus of claim 1 , further comprising:

a gear assembly to facilitate axial rotation of each axle in the same direction.

4. The apparatus of claim 1 , wherein each higher wheel assembly includes:

a wheel hub;

a set screw to secure the higher wheel assembly to a corresponding axle;

a support wheel; and

an O-ring around a perimeter of the support wheel.

5. The apparatus of claim 1 , wherein each lower wheel assembly includes:

a wheel hub;

a set screw to secure the lower wheel assembly to a corresponding axle;

a support wheel;

an O-ring around a perimeter of the support wheel; and

a stopper.

6. The apparatus of claim 4 , wherein each lower wheel assembly includes:

a wheel hub;

a set screw to secure the lower wheel assembly to a corresponding axle;

a support wheel;

an O-ring around a perimeter of the support wheel; and

a stopper.

Assignments (11)