Shaft-expanding frustoconical lock

#This application relates to a lock for connecting a shaft to a hub, wheel, crank or other mating piece such that torque can be transmitted between the two. In particular, this application relates to a lock having a frustoconical component that is inserted into the shaft.

#U.S. Pat. No. 3,957,381 to Schafer discloses a coaxial, double-cone, frictional hub-to-shaft connector. The connector includes two clamping rings. The inner surface of the outer ring and the outer surface of the inner ring are conical surfaces, which engage with each other. Tightening screws to the side of the shaft tighten the connector by drawing the rings together in axial direction. As the rings are drawn together, the inner ring clamps against the shaft and the outer ring against an inner surface of the hub.

#Splines are ridges or teeth on a shaft that mesh with grooves in a hub or gear wheel, for example, that is located on the shaft. Spline connections allow torque to be transferred between the shaft and the mating piece. Some spline connections are prone to backlash. An alternative to splines is a keyway and key, which, however, may not be as durable.

#The following drawings illustrate embodiments of the invention, which should not be construed as restricting the scope of the invention in any way.

#FIG. 1 is a cross-sectional view of a shaft-expanding cone lock according to one embodiment of the present invention.

#FIG. 2 is a side view of the cone piece of FIG. 1.

#The term “mating piece” refers to a crank, a hub, a wheel, a gear or any other mechanical component that is to be attached to a shaft, such that torque can be transferred either from the shaft to the mating piece or from the mating piece to the shaft.

#The term “cone piece” refers to the component of the shaft-expanding cone lock that is inserted and tightened into the end of a shaft. The cone piece has at least one frustoconical portion, which engages with a corresponding frustoconical surface inside the end of the shaft.

#The term “frustoconical” relates to the shape of a conical frustum, i.e. a cone with its apex removed such that the cut surface is parallel to the base of the cone.