Abstract: A clamping mechanism is provided to prevent movement of the rotatable stock carrier of a multiple spindle bar machine after it has rotated into position for the machining operation. The clamping mechanism comprises a controllable locking pin to engage indexing pin slots on the stock carrier, a passive pressure brake located opposite the locking pin, and a hydraulically actuated pressure brake in the same quadrant as the locking pin. The hydraulically actuated brake clamps the carrier against the passive brake, and in combination with the locking pin holds the carrier against movements caused by the forces of the machining tools. The hydraulic brake is released by a programmable controller to allow intended rotation of the carrier to a new position.

Abstract: A method and means for accurately positioning a tool slide in an automatic machining apparatus. Said method and means utilizing a fluid operated drive means, a linear position detecting means, an encoder means operatively associated with said linear position detecting means, means for controlling fluid flow to said fluid operated drive means and a programmable controller means for receiving and storing control data information and for receiving coded information for comparison to said control data information and for outputting a signal to control the operation of said fluid drive means.