Brake for turn counting shaft drive knob - comprises radial braking ring which acts on floating shoes housed in plate concentric with shaft

摘要

The braking ring which is of monobloc construction of a plastics material acts on independent floating shoes which are located in a plate. The braking ring which is circular and concentric acts as a cam to displace the shoes in a radial direction to apply an axial clamping force directly on the hub to prevent it turning. The braking ring indicates the angular position for the shaft w.r.t an origin. The braking ring rests on a moulded base. When the ring is rotated a system of mortices and bosses displace the ring longitudinally causing it to press against an anti-rotation ring which pushes against a toroidal joint.