Electromagnetic transducer apparatus

Claim 1

ELECTROMAGNETIC TRANSDUCER CONTROL AND POSITIONING APPARATUS COMPRISING: (A) AN ELECTROMAGNETIC TRANSDUCER INCLUDING ONE OR MORE READ-RECORD HEADS, (B) A ROTATABLE RECORD MEMBER HAVING A MAGNETIZABLE SURFACE THEREON, SAID MAGNETIZABLE SURFACE BEING DIVISIBLE INTO A PLURALITY OF DISCRETE RECORDING AREAS OR TRACKS CIRCULARLY DISPOSED IN CONCENTRIC FASHION AROUND SAID RECORD MEMBER, (C) MEANS AUTOMATICALLY, ADJUSTABLY BIASING SAID TRANSDUCER TOWARD SAID RECORD MEMBER, (D) MEANS TO ROTATE SAID RECORD MEMBER, (E) MEANS ENGAGEABLE WITH SAID TRANSDUCER FOR RECTILINEARLY GUIDING SAID TRANSDUCER IN STRAIGHT LINE MOTION OVER THE MAGNETIZABLE SURFACE OF SAID RECORD MEMBER IN HYDRODYNAMIC AIRBEARING RELATIONSHIP THEREWITH, (F) A CAM PLATE ADJACENT TO ONE END OF SAID SPACED MEMBERS, (G) A CAM FOLLOWER CARRIED BY SAID TRANSDUCER ENGAGEABLE WITH SAID CAM PLATE EFFECTIVE THEREBY FOR DISPLACING SAID TRANSDUCER RELATIVE TO SAID RECORD MEMBER, PREVENTING SAID TRANSDUCER FROM ACCIDENTALLY CONTCTING AND DAMAGING THE SURFACE OF THE RECORD MEMBER, (H) A PAIR OF CONCENTRIC ESCAPEMENTS EACH HAVING A PROJECTING MEMBER, (I) OPPOSITELY DISPOSED ELECTROMAGNETS EACH INCLUDING A CLAPPER ENGAGEABLE WITH A RESPECTIVE ONE OF SAID PROJECTING MEMBERS AND EFFECTIVE WHEN ENERGIZED TO CONTROL THE MOVEMENT OF THE ASSOCIATED ESCAPEMENT MEMBER, (J) A SPIRAL CAM OPERABLY ASSOCIATED WITH SAID ESCAPEMENT MEMBERS, (K) A CAM FOLLOWER OPERABLY ENGAGEABLE WITH SAID SPIRAL CAM AND ARCUATELY MOVABLE RELATIVE THERETO AND INCLUDING MEANS BIASING THE SAME IN ONE DIRECTION AND EFFECTIVE UPON MOVEMENT OF SAID CAM FOR EFFECTING MOVEMENT OF SAID TRANSDUCER, (L) AN ELONGATED LOADING ARM INCLUDING A COILED SPRING BIASING THE SAME IN ONE DIRECTION AND OPERABLY ASSOCIATED WITH SAID TRANSDUCER MEMBER EFFECTIVE WHEN RELEASED TO DRIVE THE TRANSDUCER TO A SELECTED TRACK POSITION ON SAID RECORD MEMBER, DRIVE MEANS SELECTIVELY ENGAGEABLE WITH SAID CAM FOR MOVING SAID TRANSDUCER IN A DIRECTION OPPOSITE TO THAT IN WHICH IT IS DRIVEN BY MEANS OF SAID LOADING ARM, AND (M) ELECTRICAL CONTROL MEANS OPERABLY ASSOCIATED WITH SAID ESCAPEMENT MEMBERS EFFECTIVE TO CONTROL THE INCREMENTAL ADVANCEMENT OF SAID ESCAPEMENT MEMBERS EFFECTIVELY POSITIONING SAID TRANSDUCER ADJACENT THE TRACKS OF SAID RECORD MEMBER IN RESPONSE TO ENERGIZATION OF SAID ELECTROMAGNETIC MEANS.