DRIVE MECHANISM FOR OSCILLATORY DENTAL TOOL WITH IMPROVED BUSHING

摘要

A transmission for changing rotary motion into angularly reciprocating motion and adapted to be mounted on the output end of a dental power unit of the type having a rotary drive output and used to drive a dental tool. The transmission is comprised of a support member (42), a driving resinous member (30) supported by the support member (42) for rotary motion, and a driven resinous member (40) supported by the support member (42) for reciprocating angular movement by the support member (42). The transmission subassembly is formed by the driving resinous member (30), driven resinous member (40) and support member (42) and adapted to be mounted on the output end of the dental power unit with a rotary drive output mechanically coupled to the driving resinous member (30). A driving cam surface (50) is disposed on a portion of the driving resinous member (30). A driven cam surface (60) is disposed on a portion of the driven resinous member (40). The driving cam surface (50) is in contact with the driven cam surface (60) during at least a portion of the cycle of rotation of the driving cam surface (50). The driven cam surface (60) is configured and dimensioned to be driven by the driving cam surface (50) in a positive angular direction during one part of the cycle and is driven by the driving cam surface (50) in a negative angular direction during another part of the cycle. Angularly reciprocating motion is thereby imparted to the dental tool as the driving cam surface (50) and driven cam surface (60) engage each other. The tool is also useful for non-dental purposes when appropriate heads are added.