High speed machine tool spindle - has rod actuated cone chuck and uses two-way release jack with inversely sliding case taking piston reaction force

摘要

The high speed machine tool spindle (1) uses a cone chuck (7) to secure the bit (8), using a housed push-rod (6) chuck-control. A spring (61) effects rod retraction so that the chuck (7) grips the bit (8). The piston hammer (42) is driven by pneumatics to move the rod against the spring (61) and effect bit release. The piston (42) is incorporated in a two-way jack (3), its casing (31) sliding in the main housing to counter the piston forces and protect the shaft bearings (51,57). A floating piston (32) may close the trailing end of the casing, the leading end being internally flanged (39). Compressed air enters the chamber (30) to drive the piston, simultaneously effecting an inverse displacement of the piston (32). The casing, thus, moves inboard for the flange (39) to engage nut (55) and prevent the transmission of piston (42) forces to bearings (51,57).