Extension shaft for holding a tool for rotary driven motion

Abstract

An extension shaft for holding a tool for rotary motion of the tool includes a first end adapted to cooperate with a chuck of a handheld instrument and a second end including a tool holder for holding the tool for rotary driven motion thereof. The tool holder includes a base portion operatively connected to the extension shaft and a swivel portion capable of holding the tool. The swivel portion is pivotly coupled to the base portion through a pivot assembly, wherein the tool is capable of being rotated about an angle with respect to an axis of the chuck through rotation of the extension shaft in response to rotation of the chuck.

1 . An extension shaft for holding a tool for rotary driven motion, the extension shaft having an axis and capable of being adapted to a handheld instrument having a chuck, the extension shaft comprising, in combination:
 a first end adapted to cooperate with the chuck and a second end adapted to hold the tool for rotary driven motion, the first end of the extension shaft and the chuck having complementarily shaped non-circular cross-sections; and,   the second end of the extension shaft including a tool holder for holding the tool for rotary driven motion thereof, the tool holder and the tool having complementarily shaped non-circular cross-sections, the tool holder further including a base portion and a swivel portion, the swivel portion being capable of holding the tool and further being pivotly coupled to the base portion through a pivot assembly including a ball joint having a bearing and a socket, wherein the tool is capable of being rotated about an angle with respect to an axis of the chuck through rotation of the extension shaft in response to rotation of the chuck.   
     
     
         2 . The extension shaft of  claim 1  further comprising a sheath substantially covering the pivot assembly. 
     
     
         3 . The extension shaft of  claim 1 , further comprising a spacer located about the axis of the extension shaft and proximate the ball joint. 
     
     
         4 . The extension shaft of  claim 1 , wherein the tool holder is configured to predispose an axially aligned connection of the base and swivel portions when the extension shaft is at rest. 
     
     
         5 . An extension shaft for holding a tool for rotary driven motion, the extension shaft capable of being adapted to a handheld instrument having a chuck, the extension shaft comprising, in combination:
 a first end adapted to cooperate with the chuck and a second end adapted to hold the tool for rotary driven motion, the first end of the extension shaft and the chuck having complementarily shaped non-circular cross-sections; and,   the second end of the extension shaft including a tool holder for holding the tool for rotary driven motion thereof, the tool holder and the tool having complementarily shaped non-circular cross-sections, the tool holder further including a base portion and a swivel portion, the swivel portion being capable of holding the tool and further being pivotly coupled to the base portion through a pivot assembly having a first pin and a second pin wherein the first and second pins are substantially perpendicular to each other and lie substantially within a plane, and further wherein the tool is capable of being rotated about an angle with respect to an axis of the chuck through rotation of the extension shaft in response to rotation of the chuck.   
     
     
         6 . The extension shaft of  claim 5 , wherein the pivot assembly is a unitary piece and the first and second pins are connected to each other. 
     
     
         7 . The extension shaft of  claim 6 , wherein the pivot assembly includes a hub from which the first and second pins extend there from. 
     
     
         8 . The extension shaft of  claim 7  wherein the hub includes a geometric shape that lies substantially within the plane. 
     
     
         9 . The extension shaft of  claim 7  wherein the hub is circular. 
     
     
         10 . The extension shaft of  claim 7  wherein the hub is a polygon. 
     
     
         11 . The extension shaft of  claim 10  wherein the hub is square. 
     
     
         12 . The extension shaft of  claim 7  wherein the hub includes a geometric shape having a portion that extends substantially outside the plane. 
     
     
         13 . The extension shaft of  claim 12  wherein the hub is round. 
     
     
         14 . The extension shaft of  claim 12  wherein the hub is cylindrical. 
     
     
         15 . The extension shaft of  claim 12  wherein the hub is polygon. 
     
     
         16 . The extension shaft of  claim 15  wherein the hub is square. 
     
     
         17 . The extension shaft of  claim 5 , further being flexible and capable of being deflected with respect to the axis of the chuck so as to position the second end of the extension shaft at an angle relative to the axis of the chuck. 
     
     
         18 . The flexible extension shaft of  claim 17 , further including a plurality of concentric coil springs in tightly wound adjacent relation extending between and secured to generally cylindrical body portions proximate the first and second ends of the flexible extension shaft to accommodate deflection of the flexible extension shaft relative to the axis of the chuck, and including a flexible sleeve disposed about the concentric coil springs, the flexible sleeve having cylindrical fittings secured thereto at opposite ends thereof so as to define a shoulder internally of each of the fittings, the cylindrical fittings each being adapted to receive one of the cylindrical body portions therein, the cylindrical body portions being spaced apart by a distance greater than the distance between the shoulders in the cylindrical fittings to permit limited axial movement of the cylindrical body portions and the concentric coil springs relative to the cylindrical fittings and the flexible sleeve. 
     
     
         19 . The flexible shaft extension of  claim 18  further comprising a shaft biasing coil spring disposed about the concentric coil springs of the flexible extension shaft, the shaft biasing coil spring being disposed between the shoulder in one of the cylindrical fittings and the corresponding one of the cylindrical body portions to normally bias the other of the cylindrical body portions into engagement with the shoulder in the other of the cylindrical fittings. 
     
     
         20 . A flexible extension shaft for holding a tool for rotary driven motion, the flexible extension shaft having an axis and capable of being adapted to a handheld instrument having a chuck, the flexible extension shaft comprising, in combination:
 a first end adapted to cooperate with the chuck and a second end adapted to hold the tool for rotary driven motion, the first end of the flexible extension shaft and the chuck having complementarily shaped non-circular cross-sections, the first end having an axis and capable of being received by the chuck wherein the first end and the chuck cooperate to releasably retain the first end within the chuck;   the second end of the flexible extension shaft including a tool holder for holding the tool for rotary driven motion thereof, the tool holder and the tool having complementarily shaped non-circular cross-sections, the tool holder further including a base portion and a swivel portion, the swivel portion being capable of holding the tool and further being pivotly coupled to the base portion through a pivot assembly including a ball joint having a bearing and a socket, wherein the tool is capable of being rotated about an angle with respect to an axis of the chuck through rotation of the extension shaft in response to rotation of the chuck;   a means for predisposing an axially aligned connection of the base portion and the swivel portions when the flexible extension shaft is at rest;   the flexible extension shaft being deflectable relative to an axis of the chuck so as to position the second end of the flexible shaft and the tool at an angle relative to the axis of the chuck, the tool capable of being rotary driven by the handheld instrument through the flexible extension shaft; and,   the flexible extension shaft further including a plurality of concentric coil springs in tightly wound adjacent relation extending between and secured to generally cylindrical body portions proximate the first and second ends of the flexible extension shaft to accommodate deflection of the flexible extension shaft relative to the axis of the chuck, and including a flexible sleeve disposed about the concentric coil springs, the flexible sleeve having cylindrical fittings secured thereto at opposite ends thereof so as to define a shoulder internally of each of the fittings, the cylindrical fittings each being adapted to receive one of the cylindrical body portions therein, the cylindrical body portions being spaced apart by a distance greater than the distance between the shoulders in the cylindrical fittings to permit limited axial movement of the cylindrical body portions and the concentric coil springs relative to the cylindrical fittings and the flexible sleeve.   
     
     
         21 . The extension shaft of  claim 20 , wherein the means for predisposing an axially aligned connection of the base portion and the swivel portion of the tool holder comprising:
 a first annular surface extending about the perimeter of the base portion proximate the ball joint;   a second annular surface extending about the perimeter of the swivel portion proximate the opening of the socket; and,   a retaining device secured within the socket and about the axis of the base portion proximate the bearing of the ball joint.   
     
     
         22 . The extension shaft of  claim 21 , wherein at least a portion of one of the base and swivel portions being magnetized to attract each into an axially aligned connection. 
     
     
         23 . The extension shaft of  claim 21 , further comprising a bias positioned within the socket and about the axis of the ball joint and between the retaining device and the bearing of the ball joint, wherein the bias exerts a force to bring the cooperating first and second annular surfaces into engagement. 
     
     
         24 . The extension shaft of  claim 21 , wherein the retaining device is a slip nut operatively affixed and positioned within the socket. 
     
     
         25 . The extension shaft of  claim 21 , wherein the bias is a spring.