Angle encoder

Claim 1

APPARATUS OF THE CLASS DESCRIBED COMPRISING: A DRUM ROTATABLE ABOUT AN AXIS AND HAVING A FIRST, A SECONE, A THIRD, AND A FOURTH SIGNAL PRODUCING MEANS THEREON, THE SURFACES TRACED BY SAID FIRST, SECOND THIRD AND FOURTH SIGNAL PRODUCING MEANS DESCRIBING FIRST, SECOND, THIRD AND FOURTH SIGNAL TRACKS RESPECTIVELY WHEN SAID DRUM ROTATES ABOUT SAID AXIS, SAID FIRST AND SECOND SIGNAL PRODUCING MEANS BEING SUBSTANTIALLY COLINEAR IN A LINE PARALLEL TO THE AXIS OF THE DRUM AND SAID THIRD AND FOURTH SIGNAL PRODUCING MEANS BEING SUBSTANTIALLY COLINEAR IN A LINE PARALLEL TO THE AXIS OF SAID DRUM, AND SAID THIRD AND FOURTH SIGNAL PRODUCING MEANS BEING DISPLACED 180* AROUND THE PERIPHERY OF SAID DRUM SAID FIRST AND SECOND SIGNAL PRODUCING MEANS; A FIRST SIGNAL RESPONSIVE MEANS MOUNTED IN A FIXED RELATIONSHIP TO SAID FIRST SIGNAL TRACK WHEREBY SAID FIRST SIGNAL RESPONSIVE MEANS DELIVERS A SIGNAL WHEN SAID FIRST SIGNAL PRODUCING MEANS IS PROXIMITY THERETO; A THIRD SIGNAL RESPONISVE MEANS MOUNTED IN A FIXED RELATIONSHIP TO SAID THIRD SIGNAL TRACK, AND DISPLACED SUBSTANTIALLY 180* AROUND THE PERIPHERY OF SAID DRUM FROM SAID FIRST SIGNAL RESPONSIVE MEANS, WHEREBY SAID THIRD SIGNAL RESPONSIVE MEANS DELIVERS A SIGNAL WHEN SAID THIRD SIGNAL PRODUCING MEANS IS IN PROXIMITY THERETO; SECOND AND FOURTH SIGNAL RESPONSIVE MEANS ROTATABLY MOUNTED AROUND SAID AXIS IN PROXIMITY TO SAID SECOND AND FOURTH SIGNAL TRACKS RESPECTIVLEY AND MOVABLE WITH RESPECT TO SAID FIRST AND THIRD SIGNAL RESPON-IVE SIVE MEANS WHEREBY SAID SECOND SIGNAL RESPONSIVE MEANS DELIVERS A SIGNAL WHEN SAID SECOND SIGNAL PRODUCING MEANS IS IN PROXIMITY THERETO, AND SAID FOURTH SIGNAL RESPONSIVE MEANS DELIVERS A SIGNAL WHEN SAID FOURTH SIGNAL PRODUCING MEANS IS IN PROXIMITY THERETO, SAID SECOND AND FOURTH SIGNAL RESPONSIVE MEANS BEING DISPLACED SUBSTANTIALLY 180* FROM EACH OTHER; PULSE GENERATING MEANS FOR GENERATING PULSE AT A PARTICULAR FREQUENCY; PULSE COUNTING MEANS; AND GATING MEANS CONNECTING SAID PULSE GENERATING MEANS AND SAID PULSE COUNTING MEANS AND OPERABLE IN RESPONSE TO THE SIGNALS FROM SAID FIRST, SECOND, THIRD AND FOURTH SIGNAL RESPONSIVE MEANS TO CAUSE SAID PULSE COUNTING MEANS TO COUNT ONE-HALF THE PUSLE FROM SAID PULSE GENERATING MEANS DURING THE TIME BETWEEN THE SIGNALS FROM SAID FIRST AND THIRD SIGNAL RESPONSIVE MEANS, ALL OF THE PULSES FROM THE PULSE GENERATING MEANS BETWEEN THE SIGNALS FROM SAID THIRD AND SECOND SIGNAL RESPONSIVE MEANS AND ONE-HALF THE PULSES FROM SAID PULSE GENERATING MEANS BETWEEN THE SIGNAL FROM SAID SECOND AND FOURTH SIGNAL RESPONSIVE MEANS.