Patent ID: 6857707

Claim:
A wheel including: (a) an integrally formed wheel frame including: (i) a central hub rotatable about a main axis; (ii) a plurality of first supports in a first plane transverse to the main axis and radially spaced from the central hub to form a first discontinuous rim; and (iii) a plurality of second supports radially spaced from the hub to form a second discontinuous rim, said second supports in a second plane transverse to the main axis and parallel to, and spaced from, the first discontinuous rim; (b) a first series of rollers regularly spaced around the first rim and supported for rotation by the plurality of first supports; and (c) a second series of rollers regularly spaced around the second rim and supported for rotation by the plurality of second supports, wherein, (iv) each roller has a main body wherein the lateral cross-sectional diameter is greater than the diameter of the end portions of the main body; (v) each roller is rotatable about an axis transverse to the main axis; and (vi) when viewed in side elevation, the effective ground contacting surface of each roller of the first series of rollers overlaps with the effective ground contacting surface of each diagonally adjacent roller of the second series of rollers to the extent of between 20 and 35% of the length of each roller, so that the wheel is adapted to make effective ground contact through the main body of at least one of the rollers at any one time for improved travel parallel to said main axle.