System for automatically positioning multiple tool-holding carriages.

摘要

A system for automatically positioning a plurality of tool-holding carriages (32) along an elongate guide member (10) utilizes a single drive member (36) to move all of the carriages simultaneously. The carriages (32) each have clutches (50, 52) for selectively engaging or disengaging the drive member (36) so that the carriages (32) can be moved relative to each other by the drive member (36), and can be moved simultaneously in opposite directions along the guide member if desired. The drive member (36) is capable of moving each carriage (32) throughout its respective maximum range of movement with a continuous motion, without any reversal of the drive member of any disengagement of the respective carriage from the drive member. Each carriage (32) has an electrically-powered position sensor (54) capable of transmitting different discrete signals for different positions of the carriage so that it provides absolute indications of position rather than indications which are relative to some reference position.