Patent ID: 7909501

Claim:
A safety system for selectively permitting a motor to drive an implement, within a container, in rotation about an axis; the system comprising a detent member associated with the motor or the implement and rotatable therewith; a trapping member movable between first and second positions, spaced apart in a direction parallel to said axis, for respectively trapping and releasing said detent member; means constraining said trapping member against rotation; means actuated by the container for moving the trapping member into said second position when said container is correctly placed to contain said implement, and means otherwise urging said trapping member into said first position; the system thereby permitting said implement to be driven in rotation by the motor when said container is correctly placed to contain said implement, and otherwise preventing the implement from being so driven; wherein: (a) the container comprises a bottomless goblet having a base side-wall adapted to be located in place around said implement by a readily releasable and securable means such as screw threads or a bayonet fixing; (b) the means for moving the trapping member is responsive to a lower rim of the side-wall of said bottomless goblet; (c) the detent member comprises a collar with at least one outwardly facing tooth and/or at least one socket; and (d) the trapping member comprises an apertured interlock plate; said aperture being sufficiently large to accommodate the collar, and being defined by a wall formed with at least one further socket disposed to receive said at least one tooth, and/or at least one further tooth disposed to engage with said at least one socket, when the interlock plate is so disposed axially along a motor shaft as to surround the collar.