Load weight induced self aligning castor for trolley

A self aligning castor assembly comprises an axially mounted wheel 1, and a spindle 3, housed within a cylinder 4 which may be a tubular element of a trolley frame, being freely rotatable and vertically displaceable, possibly against the bias of a spring 8, the cylinder 4 further features a bearing, possibly shaped as a truncated cone, which contacts a swash plate 7 of the castor assembly. The assembly may provide increased tendency to align as a function of forces applied vertically through the cylinder 4. If the pairs of the assembly are mounted to a rear of a trolley, a relatively high trolley load may attenuate the undesirable tendency of a relatively heavily loaded trolley to displace sideways across a sloped surface when being pushed, also known as "crabbing".