Adaptive, ergonomic, multi-purpose hand-held tool with flexible drive shaft

Abstract

An adaptive, ergonomic designed multi-purpose air motor driven hand-held trimmer that uses the air motor as the handle, has the air motor offset at an angle of 25 degrees to the fore and aft axis of the base plate and downward 10 degrees, to thereby have the center of gravity as near as possible to the wrist of the operator so that there will not be a constant bending of the wrist or exerting of constant hard pressure on the tissue at the base of the hand, thus virtually eliminating the possibility of the operator acquiring the carpal tunnel syndrome. Further disclosed are particular flexible drive shafts which may be used in the tool.

1 . A highly flexible drive shaft which is capable of transmitting high levels of torque, said drive shaft comprising:
 an elongated strip of a titanium material, said strip having a length dimension, a width dimension which is less than said length dimension, and a thickness dimension which is less than said width dimension, said strip being wound into a helical coil, said helical coil having a first and a second end;   a first coupler affixed to the first end of the coil; and   a second coupler affixed to the second end of said coil.   
   
   
       2 . The flexible drive shaft of  claim 1 , wherein said helical coil is a closed helical coil wherein said coil is wound so as to produce a plurality of turns wherein each turn of said coil overlaps with an adjacent turn. 
   
   
       3 . The flexible drive shaft of  claim 1 , wherein said elongated strip is non-planar with regard to its width dimension. 
   
   
       4 . The flexible drive shaft of  claim 3 , wherein said strip is curved along its width dimension. 
   
   
       5 . The flexible drive shaft of  claim 1 , wherein said titanium material comprises pure titanium. 
   
   
       6 . The flexible drive shaft of  claim 1 , wherein said titanium material comprises an alloy of titanium. 
   
   
       7 . The flexible drive shaft of  claim 6 , wherein said alloy of titanium includes aluminum and vanadium. 
   
   
       8 . The flexible drive shaft of  claim 7 , wherein said alloy of titanium includes, on a weight basis, 6% aluminum and 4% vanadium. 
   
   
       9 . The flexible drive shaft of  claim 1 , wherein the thickness of said elongated strip of a titanium material is in the range of 0.010 to 0.035 of an inch. 
   
   
       10 . A hand tool which includes the flexible drive shaft of  claim 1 . 
   
   
       11 . A motor driven hand-held tool comprising:
 a housing;   a motor which is supported by said housing, said motor being elongated along a center line, said motor being disposed in a motor housing having a diameter in the range of 1 to 2.5 inches so that when the tool is in use, the motor housing is directly gripped by a user's hand so that the tool may be supported solely by said hand, said motor having a power shaft which is driven thereby when the motor is energized;   an output shaft which is rotatably supported in the housing and which is configured to receive and retain a tool bit;   a flexible drive shaft in accord with  claim 1 , which is disposed so as to join the power shaft of the motor and the output shaft, so that power can be transmitted therebetween so as to rotate the tool bit;   wherein said housing is configured so that the center line of the motor and a central axis of the output shaft intersect so as to form an angle which is less than 90 degrees.   
   
   
       12 . A flexible drive shaft for a hand-held tool having a rotary drive component, said drive shaft comprising:
 a cable comprising a plurality of wound wire strands;   a composite body of a polymer-impregnated carbon fiber composition wrapped about said cable;   a sleeve of a second carbon fiber material disposed around said composite body.   
   
   
       13 . The drive shaft of  claim 12 , wherein said body of polymer impregnated carbon fiber comprises a carbon fiber impregnated with a curable polymer. 
   
   
       14 . The drive shaft of  claim 12 , wherein said curable polymer is a heat curable polymer.