Variable height support

A variable height support comprising:

• a platform defining an upwardly facing support surface;
• a base for supporting the platform in an operative position upon a subjacent surface and reconfigurable to selectively change a height of the support surface relative to the subjacent surface;
• and
• a control assembly that is operable to selectively:
• a) maintain the support surface at a selected height;
• and b) release the platform to allow the base to be reconfigured to change the height of the support surface relative to the subjacent surface,
• wherein the control assembly comprises a ratchet subassembly that, with the control assembly in a first state, interacts between the platform and base to allow the base to be reconfigured by exerting a continuous upward force upon the platform that causes the platform to elevate relative to the subjacent surface over a range and be blocked within the range at a plurality of different vertical locations against downward movement relative to the subjacent surface, wherein the ratchet subassembly comprises a first toothed bar that is mounted for pivoting movement relative to the platform about an axis, wherein the control assembly further comprises an actuator that is repositionable between a normal position and an actuated position thereby to change the control assembly from the first state into a second state wherein the platform can be lowered over the range,
• wherein the first toothed bar is biasably urged towards an engaged position and is movable from the engaged position into a disengaged position as an incident of the actuator being changed from the normal position into the actuated position,
• further comprising a lock assembly that is changeable between a locked state and an unlocked state, the lock assembly in the locked state fixing the first toothed bar in the engaged position, the lock assembly in the unlocked state allowing the first toothed bar to be moved from the engaged position to the disengaged position by the actuator, wherein the lock assembly comprises a in that is directed into the first toothed bar and platform with the lock assembly in the locked state.