Patent ID: 8079606

Claim:
A wheel assembly comprising: a wheel bracket, and a wheel rotationally mounted thereto; a swivel shaft, the wheel bracket being mounted to the shaft to swivel, together with the wheel, about the shaft; a locking element mounted to the swivel shaft; an engagement element arranged for releasable engagement with the locking element to restrict swivelling of the wheel bracket about the swivel shaft; and at least one actuator element arranged for contact with a peripheral surface of the wheel and operatively coupled with the engagement element whereby, while the engagement element is fully engaged with the locking element, rotation of the wheel in one direction only urges the actuator element into increased pressing engagement with the wheel for disengagement of the engagement element from the locking element to permit swivelling of the wheel bracket together with the wheel, the engagement and actuator elements also being arranged with further rotation of the wheel in said one direction to decrease or maintain constant said pressing engagement following said disengagement.