Numerical controller for cam grinding machine

A numerical controller for controlling pulse distribution to a cam drive unit for rotating a cam to be ground and to a grinding wheel drive unit for moving a grinding wheel to thereby grind said cam to a desired cam profile, comprising:

• first memory means for storing a plurality of profile data respectively corresponding to a plurality of angular ranges through which said cam is rotated, each of said profile data representing the number of pulses which are to be distributed to said grinding wheel drive unit when said cam is rotated through one of said angular ranges corresponding to said each of said profile data;
• first feed rate calculation means for calculating, respectively based upon said plurality of said profile data stored in said first memory means, a plurality of first distribution speeds which respectively correspond to said plurality of said angular ranges and at each of which pulses are to be distributed to one of said cam unit and said grinding wheel drive unit when said cam is rotated through a corresponding one of said angular ranges, each of said first distribution speeds being inversely proportional to the number of pulses which is represented by a corresponding one of said profile data;
• second memory means for storing a plurality of data respectively indicative of said plurality of said first distribution speeds calculated by said first feed rate calculation means;
• data output means operable each time said cam is rotated through one of said angular ranges for outputting one of said profile data and one of said first distribution speed data corresponding to a successive one of said angular ranges respectively from said first and second memory means and for further outputting numerical data indicative of the number of pulses which are to be distributed to said cam drive unit when said cam is rotated through said successive one of said angular ranges;
• second feed rate calculation means for calculating, based upon said one of said profile data, said one of said first distribution speed data and said numerical data output by said data output means, a second distribution speed at which pulses are to be distributed to the other of said cam drive unit and said grinding wheel drive unit when said cam is rotated through said successive one of said angular ranges;
• and
• pulse distribution means responsive to said one of said first distribution speed data output from said second calculation means for distributing pulses to said one of said cam drive unit and said grinding wheel drive unit at said second distribution speed.