| 摘要 |
The present invention relates to an automatic clamping unit of the type having a spring loaded lock rod that is movable between an unlocked and locked position. A pair of locking balls are confined about the locking rod and are operative to move outwardly for engagement with the shank of a tool holder in response to the locking rod moving from the unlocked position to the locked position. The lock rod of the present invention includes a variable sloped ramp for engagement with each locking ball. As each locking ball moves along the variable sloped locking ramp, the mechanical advantage applied to the locking balls through the ramp varies due to the variation in slope. Each locking ramp is particularly configured such that the resultant locking load exerted by the locking balls against the shank of the tool holder is relatively constant although the position of the locking rod and the force being applied to the locking rod varies. |
