GB1301940A - - Google Patents

Abstract

1301940 Wheels R B BUCKNELL 15 July 1971 [23 July 1970] 35750/70 Heading B7C A wheel comprises a first rolling portion and a second rolling portion of greater diameter and smaller surface area than the first portion, such that in use of the wheel on hard ground the second portion only contacts the ground whereas on soft ground both the second portion and at least part of the first portion contact the ground, the wheel thus providing little rolling resistance on hard ground whilst also providing a ground contacting area of larger size on soft ground to minimize sinking of the wheel. The wheel may comprise a hollow shell 1, consisting of a first rolling, portion 5 and a second rolling portion 4, protruding radially outwardly slightly beyond the first portion 5, of substantially cylindrical form with a circular end face 2, the first portion 5 tapering from the second portion to a smaller end with a substantially circular face 3, the second portion 4 being of thicker shell material and of greater rigidity than the first portion 5, the latter being resiliently flexible. The circular face 2 is formed with corrugations 6 radiating from the centre to form ribs or spokes 8, the corrugations increasing in depth and breadth towards the periphery of the face, the ribs serving to strengthen and enhance the rigidity of the second portion 4, and the face 3 is formed with corrugations 9 which radiate from the centre and decrease in depth towards the periphery of the face. Apertures are formed one at the centre of each of the faces 2, 3 and a plastics tube 12 extends between the apertures sealing the shell and providing a sleeve for an axle. The shell may be made from plastics using a rotary moulding technique. The wheel is buoyant and may be used, for example, on a boat launching trolley.