Duplex CAMS

Duplex CAMS

Duplex CAMS - If the working stroke of a slide alternates with an indexing cycle to change the position of the workpiece (spindle carrier of multiple spindle automatics) or of the tools (turret of automatic screw machines), then the slides with tools arranged coaxially with the workpiece must be rapidly withdrawn from the machining zone, to avoid collisions in indexing, and then rapidly advanced again into the machining zone.

Special devices are used in such cases for rapid approach to and withdrawal from the cutting zone. An additional rapid approach and withdrawal earn, paired with the working feed earn, is used for the end tool slide of multiple spindle automatics; a special crank gear mechanism, powered by a high speed drive, is used to advance and retract the turret slide.

Duplex (positive return) cams are mounted on the camshaft of an automatic adjacent to each other. The length of working travel is adjusted by varying the arms of levers that transmit motion from the working feed cam to the slide. The length and rate of approach actuated by the slide approach earn remain constant.

To increase the rate of approach and withdrawal, the earn shaft, carrying the duplex cams, rotates at a higher speed, as a rule, than it does during working feed of the slide actuated by the working feed earn. Duplex cams may be of either the drum (cylinder) or disk (plate) type.

Figure illustrates schematically the drive of end (main) tool slide 2 in the model 1240-6 six spindle automatic accomplished by means of working feed earn 6 and rapid approach cam 8, mounted adjacently on the camshaft. The length of travel at the working feed is set up by adjusting the point at which the end of the tie rod is fastened to lever 5.

End Tool Slide Drive Mechanism with Duplex Cams