| 摘要 |
A tap holder characterized in that its cylindrical shank is axially movably and non-rotatably keyed within a tubular socket of a housing by keys having rolling engagement with complemental axially extending V grooves in the shank and in drive blocks disposed in axially extending slots of the socket, and engaged within a retainer sleeve which locates the drive blocks and keys coaxially of the shank for uniform distribution of torque loads to prevent high pressure sliding contact of the shank with the socket under torque load during relative axial movement of the housing and tap holder. The shank is additionally spring-connected to the socket by two coil springs both of which yieldably oppose relative axial movement in one direction and but one of which yieldably opposes relative axial movement in the opposite direction. The tap holder herein is further characterized in that the keys are perpendicularly related cylindrical rollers in each drive block and shank groove for rolling engagement with one pair or the other of parallel faces of said grooves according to the direction of the torque load between the housing and the tap holder during relative axial movement. |
