In or relating to trolleys

A trolley comprising a retractable wheel assembly movable between stored and in-use positions, the wheel assembly comprising:

• an assembly support;
• at least one wheel arm operably-connected to a wheel hub, in use the wheel hub receiving a wheel;
• at least one control arm operably-connected to the wheel hub, for affecting the orientation of the wheel hub with respect to the wheel arm as the retractable wheel assembly is moved between the stored position and the in-use position;
• and
• drive means connected to the assembly support and operably connected to the at least one wheel arm and at least one control arm, for providing rotation of the at least one wheel arm and at least one control arm about a first axis between the stored position and the in-use position, wherein the at least one wheel arm is also pivotally-connected to the drive means about a second axis, such that both a rotational movement of the at least one wheel arm about the first axis and a pivotal movement of the at least one wheel arm about the second axis result in movement of the retractable wheel assembly between the stored position and the in-use position,
• wherein the drive means comprises, for each wheel arm, a rotatably mounted drive spindle, for receiving the at least one wheel arm and at least one control arm;
• and wherein the rotatably mounted drive spindle is manually or electro-mechanically rotatable;
• and wherein the rotatably mounted drive spindle comprises a portion of a cog for receiving an input drive from the manual or electro mechanical rotation means;
• and wherein the manual or electro mechanical rotation means includes a cog, for driving the rotatably mounted drive spindle, and
• wherein the drive means comprises a locking cam for interacting with portions of the at least one wheel arm, to lock that wheel arm in the in-use position, wherein the locking cam is arranged to interact with an end of the at least one wheel arm, remote from the wheel hub and wherein the locking cam is arranged to be rotatable together with the cog, to provide for both a rotational and pivotal movement of the at least one wheel arm and at least one control arm between stored and in-use positions, and a locking of the at least one wheel arm in the in-use position.