Patent ID: 8109344

Claim:
An auxiliary rotary tool drive apparatus for attachment to a hand-held rotary power tool of the type having a housing with a handgrip, a trigger, and a rotary power transmitting shaft bearing a work performing member, the auxiliary rotary tool drive apparatus comprising: an elongate auxiliary housing enclosed at a rear end; mounting means for mounting said auxiliary housing to the rotary power tool housing; an elongate auxiliary drive shaft having a longitudinal axis oriented parallel with the rotary power transmitting shaft of the rotary power tool wherein said auxiliary drive shaft is rotatably and reciprocally mounted in said auxiliary housing for movement between a rearward retracted position and a forward extended position; reciprocating drive means including converting means connected with said auxiliary drive shaft for causing linear movement of said auxiliary drive shaft between said rearward retracted position and said forward extended position responsive to rotation of said auxiliary drive shaft; auxiliary holding means at a front portion of said auxiliary drive shaft for holding a selected screw or other type fastener, a bit, or other auxiliary work performing member; a selectively engageable drive mechanism connected with the rotary power tool power transmitting shaft engageable with said auxiliary drive shaft for transferring rotary motion from the power transmitting shaft to said auxiliary drive shaft in an engaged position; wherein in the retracted position, said auxiliary holding means holding said selected screw or other type fastener, bit, or other auxiliary work performing member rearward of said work performing member of said power transmitting shaft so as not to interfere with its normal operations, and in the extended position, said auxiliary holding means holding said selected screw or other type fastener, bit, or other work performing member forward of said work performing member of said power transmitting shaft so as to allow operation of said auxiliary drive shaft unimpeded by said work performing member of said power transmitting shaft; whereby a user may carry out normal operations with said rotary power tool and use said auxiliary drive shaft for the application of screws or other type fasteners, bits, or other auxiliary work performing members without removal or replacement of the work performing member held in said holding member of said rotary power tool.