Tool head attachment mechanism

Abstract

A tool head attachment mechanism located within a tool body retains a replaceable tool head in an opening of the tool body. The mechanism includes a retaining ring including a wall having a number of apertures therethrough. A locking ring is rotatable with respect to the retaining ring. Ball bearings equivalent in number to the number of apertures are retained between the locking ring and the retaining ring. The ball bearings are sufficiently large to extend partially, but not completely through the apertures. The locking ring includes ramps equivalent in number to the number of ball bearings and against each of which a respective one of the ball bearings rolls when the locking ring is rotated with respect to the retaining ring to thereby move the ball bearings radially to partially project through said apertures and retain the tool head to the tool body

1 . A tool head attachment mechanism located within a tool body and adapted to retain a replaceable tool head in an opening of the tool body, the mechanism comprising: 
 a retaining ring including a wall having an aperture therethrough,    a locking ring rotatable with respect to the retaining ring,    a ball bearing retained between the locking ring and the retaining ring, and being sized to extend partially, but not completely through said aperture, and wherein: 
 the locking ring includes a ramp against which the ball bearing rolls when the locking ring is rotated with respect to the retaining ring to thereby move the ball bearing radially to partially project through said aperture.  
   
     
     
         2 . The mechanism of  claim 1 , including a plurality of said apertures through said retaining ring wall, 
 a plurality of said ball bearings equivalent in number to said plurality of apertures, each ball bearing being retained between the locking ring and the retaining ring, and each being sized to extend partially, but not completely through said apertures, and wherein: 
 the locking ring includes a plurality of said ramps equivalent in number to the number of ball bearings and against each of which a respective one of the ball bearings rolls when the locking ring is rotated with respect to the retaining ring to thereby move all of the ball bearings radially to partially project through said apertures.  
   
     
     
         3 . The mechanism of  claim 2 , wherein the locking ring has a lever extending radially therefrom by which the locking ring can be rotated.  
     
     
         4 . The mechanism of  claim 1 , wherein the retaining ring has a pair of radially opposed tabs by which the retaining ring is fixed with respect to the tool body.  
     
     
         5 . The mechanism of  claim 2 , wherein one end of each ramp has a deep recess within which one of said ball bearings can reside, and the other end of each ramp has a shallow recess to support said one ball bearing when it is partially projecting through one of said apertures.  
     
     
         6 . A tool body having an opening to receive a spigot member of a replaceable tool head, the tool body having a tool head attachment mechanism located in said opening, the mechanism comprising: 
 a retaining ring including a wall having an aperture therethrough,    a locking ring rotatable with respect to the retaining ring,    a ball bearing retained between the looking ring and the retaining ring, and being sized to extend partially, but not completely through said aperture, and wherein: 
 the locking ring includes a ramp against which the ball bearing rolls when the locking ring is rotated with respect to the retaining ring to thereby move the ball bearing radially to partially project through said aperture.  
   
     
     
         7 . The tool body of  claim 6 , including a plurality of said apertures through said retaining ring wall, 
 a plurality of said ball bearings equivalent in number to said plurality of apertures, each ball bearing being retained between the locking ring and the retaining ring and each being sized to extend partially, but not completely through said apertures, and wherein; 
 the locking ring includes a plurality of said ramps equivalent in number to the number of ball bearings and against each of which a respective one of the ball bearings rolls when the locking ring is rotated with respect to the retaining ring to thereby move all of the ball bearings radially to partially project through said apertures.  
   
     
     
         8 . A tool body having a replaceable tool head attached thereto, the tool head comprising an attachment spigot member having a recess formed therein and a tool head attachment mechanism located within the tool body and adapted to retain the tool head in an opening of the tool body, the attachment mechanism comprising: 
 a retaining ring including a wall having an aperture therethrough,    a locking ring rotatable with respect to the retaining ring,    a ball bearing retained between the locking ring and the retaining ring, and being sized to extend partially, but not completely through said aperture, and wherein: 
 the locking ring includes a ramp against which the ball bearing rolls when the locking ring is rotated with respect to the retaining ring to thereby move the ball bearing radially to partially project through said aperture and engage with said recess.  
   
     
     
         9 . The tool body of  claim 8  comprising a plurality of said recesses formed in an array about said spigot, and the wall of said retaining ring having a plurality of said apertures therethrough, a plurality of said ball bearings equivalent in number two said apertures and retained between the locking ring and the retaining ring and wherein the locking ring includes a plurality of said ramps against which the respective ball bearings roll when the locking ring is rotated with respect to the retaining ring to thereby more all of the ball bearing radially to partially project through said apertures and engage with respective ones of said recesses.  
     
     
         10 . A set including a tool body and a plurality of replaceable tool heads for individual attachment to the tool body, the tool heads each comprising an attachment spigot member having a recess formed therein, and a tool head attachment mechanism located within the tool body and adapted to retain each tool head in an opening of the tool body, the attachment mechanism comprising: 
 a retaining ring including a wall having an aperture therethrough,    a locking ring rotatable with respect to the retaining ring,    a ball bearing retained between the locking ring and the retaining ring, and being sufficiently large in diameter to extend partially, but not completely through said aperture, and wherein: 
 the locking ring includes a ramp against which the ball bearing rolls when the locking ring is rotated with respect to the retaining ring to thereby move the ball bearing radially to partially project through said aperture.  
   
     
     
         11 . The set of  claim 10 , including a plurality of said apertures through said retaining ring wall, 
 a plurality of said ball bearings equivalent in number to said plurality of apertures, each ball bearing being retained between the locking ring and the retaining ring, and each being sized to extend partially, but not completely through said apertures, and wherein: 
 the locking ring includes a plurality of said ramps equivalent in number to the number of ball bearings and against each of which a respective one of the ball bearings rolls when the locking ring is rotated with respect to the retaining ring to thereby move all of the ball bearings radially to partially project through respective ones of said apertures.