Digital control apparatus having actual-position and error counters for positioning machine members

Claim 1

IN MACHINE MEMBER POSITION CONTROL APPARATUS COMPRISING: MEANS FOR PRODUCING A BINARY CODED DECIMAL SIGNAL REPRESENTATIVE OF A DESIRED MACHINE MEMBER POSITION; FIRST COUNTER MEANS CONNECTED TO SAID SIGNAL PRODUCING MEANS FOR STORING SAID DESIRED POSITION SIGNAL; GATING MEANS CONNECTED TO SAID FIRST COUNTER MEANS; MEANS CONNECTED TO SAID SIGNAL PRODUCING MEANS TO SELECTIVELY APPLY GATING SIGNALS TO SAID GATING MEANS FOR EFFECTING THE TRANSFER OF THE DESIRED POSITION SIGNAL FROM SAID SIGNAL PRODUCING MEANS; ERROR SIGNAL COUNTER MEANS; GATING SIGNAL MEANS FOR SELECTIVELY APPLYING FURTHER GATING SIGNALS TO SAID GATING MEANS FOR COUNTING DOWN TO ZERO THE SIGNAL STORED IN SAID FIRST COUNTER MEANS THEREBY PROVIDING SAID DESIRED POSITION SIGNAL TO SAID ERROR SIGNAL COUNTER MEANS; SECOND COUNTER MEANS ASSOCIATED WITH SAID MACHINE MEMBER FOR PRODUCING AND ACTUAL POSITION SIGNAL IN SAID SECOND COUNTER MEANS REPRESENTATIVE OF THE TRAVEL DISTANCE OF SAID MACHINE MEMBER; MEANS FOR TRANSFERRING THE ACTUAL POSITION SIGNAL TO SAID ERROR SIGNAL COUNTER MEANS; AND MEANS IN SAID ERROR SIGNAL COUNTER MEANS FOR COMPARING SAID ACTUAL POSITION SIGNAL WITH SAID DESIRED POSITION SIGNAL TO PRODUCE A POSITION CONTROL SIGNAL.