improvement still exists in the field of energy return.
The present invention provides exemplary vehicle wheel assemblies for use with a wide range of wheeled vehicles and apparatus. In one embodiment, the wheel assembly includes a first rim portion having a first circumferential edge and a second rim portion having a second circumferential edge. The first and second rim portions are coupled together to define a trough portion between the two edges. The wheel assembly includes a cartridge disposed in the trough portion between the first and second circumferential edges. The cartridge includes a chamber portion having a plurality of spaced protrusions, a resilient member disposed over the plurality of spaced protrusions, an actuator disposed over the resilient layer, and a traction layer disposed over the actuator. The actuatoris adapted to compress the resilient layer at least partially into the chamber portion when the wheel assembly is loaded with a weight. In this manner, the wheel assembly is capable of providing energy return to the wheel assembly during rotation thereof.
In one aspect, the spaced protrusions are positioned to define at least two circumferential rings of protrusions. In another aspect, the chamber portion includes a generally trough-shaped chamber portion having first and second lips, with the resilient member in cooperation with and/or coupled to the first and second lips.
In a particular aspect, the resilient member has upper and lower surfaces, with the lower surface including a plurality of raised ridges. The raised ridges are positioned to be in cooperation with the plurality of spaced protrusions. The resilient