Retractable caster assembly having a lever in rolling engagement with a pressure plate

Claim 1

A retractable caster assembly for permanent attachment to a framework for allowing said framework to rest on a floor surface in a first stable position of the assembly, and for lowering the assembly and thereby raising at least one end of the framework above said floor surface in a second stable position of the assembly, the assembly comprising: (a) a hinge plate pivotally mounted at one end to said framework; (b) a pressure plate affixed to said hinge plate at the opposite end of said hinge plate from said pivotal mounting; (c) a caster rotatably mounted on the lower surface of said pressure plate and said hinge plate positioned so that on lowering said assembly said caster extends below the lower surface of said framework and, on raising said assembly, the lower periphery of said caster is not lower than the lower surface of said framework and is out of contact with said floor surface; (d) a lever having a fulcrum point pivotably mounted on said framework, said lever having a handle portion above said fulcrum point and an engagement point below said fulcrum point, said engagement point including a roller rolling along and against the upper surface of said pressure plate to lower said caster upon raising said handle portion of said lever, said engagement point of said lever acting directly on said pressure plate through said roller; and (e) means mounted on the upper surface of said pressure plate for restricting the travel of said roller between a point where said caster is in a fully lowered stable position supporting at least a portion of said pallet wherein said fulcrum point, said roller and the center of said caster are in substantially vertical alignment, and a point where said caster is in a fully raised position.