One-way direction control for synchronous motors

Claim 1

The combination with the shaft of a synchronous motor that is capable of starting to rotate in either direction when current is applied, a driving element rotatable about an axis, a driving connection between said shaft and said element providing for continuous rotation of said shaft and said element by said shaft in either of opposite directions, and means permitting said rotation freely in one direction and for blocking rotation in the opposite direction, said means comprising a pinion having a cylindrical body rotatably mounted on an axis parallel to said axis of the driving element and disposed in spaced relation to the periphery of said driving element, said driving element having a circumferential smoOth surface and a notch opening through said circumferential surface and one end surface of said driving element and also having a lug projecting from said end surface at one side of said notch, said body of said pinion having a plurality of equidistantly circumferentially spaced teeth, certain of which denoted primary teeth are of a radial length to enter and leave said notch during revolution of said driving element in one direction and are of a length longitudinally of said body to engage said circumferential smooth surface of said driving element while alternate teeth denoted secondary teeth are of a length longitudinally of the said body to be engaged by said lug on said driving element upon revolution of said element in either direction, each of said secondary teeth and the two of said primary teeth at opposite sides of each secondary tooth being so related to each other, to said notch and to said lug on said driving element that upon rotation of said driving element in one direction said lug will engage said secondary tooth and rotate said pinion to move one of said primary teeth into and out of said notch in the driving element and dispose both of said two primary teeth in relatively slidable contact with said circumferential surface of the driving element and thereby hold the pinion momentarily against rotation and permit free rotation of said driving element and said motor shaft in said one direction, while when the driving element is urged to rotate in the opposite direction said lug will engage said secondary tooth so that said primary teeth which are in contact with said circumferential surface on the driving element will block rotation of said pinion and said driving element and said motor shaft in said opposite direction.