Patent ID: 8146203

Claim:
A swivel castor wheel assembly configured to support a vehicle to be moved across a surface, the assembly comprising: the vehicle having front and rear wheels for movement across the surface; each rear wheel comprising a respective swivel castor wheel mounted on a first member, the swivel castor wheel having an axis of wheel rotation and a steering axis substantially coextensive with the first member and substantially normal to the axis of wheel rotation, wherein the first member is hingedly connected to a second member, and the second member is hingedly connected to the vehicle such that the steering axis is moved between first and second different rake angles without substantially changing a height of the vehicle above the surface; a curved runner cooperating with each first member, and wherein a projection is provided on the first member such that the projection moves along the runner to keep the height of the vehicle above the surface substantially constant; and wherein the projection comprises a runner wheel having an axis of rotation substantially normal to the steering axis.