Patent attributes
A self-locking device for a table elevating screw includes a rotatable disk disposed on a screw having a nut thereon, a wedged body disposed on the rotatable disk, an outer cover moveably disposed on the rotatable disk and the wedged body and a stop plate disposed on the outer cover. When the rotatable disk rotates in relation to the screw in a direction or a reverse direction, the wedged body ascends or descends in relation to the rotatable disk, maintaining a gap between the stop plate and the outer cover or generating a frictional force therebetween. By the frictional force occurred when the screw rotates in a single direction, the self-locking device can achieve a precise self-locking device for the screw in a lifting/lowering positioning task.