Method and apparatus for a reciprocating a table in response to eccentrically mounted cam

摘要

A reciprocating table has a cam follower in the nature of an elongate slot extending transversely of the reciprocating path of the table. This slot receives a cam which is eccentrically mounted on a cam support wheel. The angular position of the cam support wheel is monitored by a rotary encoder and the cam wheel is driven by a bi-directional motor under microprocessor control. The microprocessor controls the motion of the cam such that an angular quadrant centred about the position of the cam defining the most extended position of the table is not used since the table is relatively insensitive to the motion of the cam within this quadrant. In contrast, the opposite quadrant extending about the most retracted position of the table is utilized so that the cam may be moved quickly to retract the table and yet the table is naturally decelerated.