Cam Assembly
A torque-limiting driving tool having a body having an axis of rotation, an elongated shaft disposed along the axis of rotation and supported by the body, and a torque-limiting element disposed to limit the amount of torque imposed on the body which is transmitted to the elongated shaft. The torque-limiting element includes opposed cams each of which comprises a metallic cam surface and a non-metallic structural base which is disposed to hold the metallic cam surface in operable position within the body. The torque-limiting driver may have a torque-adjustment element which is operable to adjust the torque value to which the transmitted torque is limited, which may include a plug bearing threads which are compatible with threads of the body. The body may include a locking element which drivably interacts with the plug to resist spontaneous rotation of the plug.
1 . A torque-limiting driver, comprising:
a body having an axis of rotation;
an elongated shaft disposed along the axis of rotation and supported by the body, wherein the elongated shaft may be shaped in transverse cross section to provide a keying effect for drivably engaging an object to be driven; and
a torque-limiting element disposed to limit the amount of torque imposed on the body which is transmitted to the elongated shaft, comprising opposed cams each of which comprises a metallic cam surface and a non-metallic structural base which is disposed to hold the metallic cam surface in operable position within the body of the torque-limiting driver.
2 . The torque-limiting driver of claim 1 , further comprising a torque-adjustment element which is operable to adjust the torque value to which the transmitted torque is limited.
3 . The torque-limiting driver of claim 2 , wherein the torque-adjustment element comprises a plug bearing threads, and wherein the body of the torque-limiting driver comprises threads which are matingly compatible with the threads of the plug.
4 . The torque-limiting driver of claim 3 , wherein the body comprises a locking element which drivably interacts with the plug to resist rotation of the plug, whereby adjustment of the torque-adjustment element is constrained against going out of adjustment spontaneously.
5 . A cam assembly comprising:
a metallic cam surface and a non-metallic structural base.
6 . The cam assembly of claim 5 , wherein the non-metallic base is made from a moldable material selected from the group consisting of plastic and resin.
7 . The cam assembly of claim 5 , made by the process of molding the non-metallic structural base to the metallic cam surface.
8 . The cam assembly of claim 5 , made by the process of bonding the non-metallic structural base to the metallic cam surface.