Patent ID: 7153202

Claim:
A flexible shaft drive transmission having a first end connectable to a drive motor and a second end connectable to a rotary cutting tool, said transmission comprising: a. a flexible drive shaft assembly comprising a flexible elongated drive transmitting member, and a drive coupling fixed to said drive transmitting member at said first end; b. a tubular casing surrounding and coaxial with said drive shaft assembly and supporting said drive shaft assembly for rotation generally about a longitudinal axis of said drive shaft assembly relative to said casing, said casing comprising a tubular flexible conduit loosely surrounding said drive transmitting member; c. a first end fitting fixed to said conduit adjacent said first end; d. a second end fitting fixed to said conduit at said second end; e. a lubricant disposed within said casing; and f. an externally threaded bearing secured around the flexible elongated drive transmitting member such that rotation of the flexible elongated drive transmitting member causes rotation of the bearing, wherein rotation of the externally threaded bearing forces lubricant toward said first end to prevent leakage of lubricant from the second end.