Roller contact structure resiliently supported on flexible arm for measuring fin angular displacement

Claim 1

APPARATUS FOR INDICATING THE ANGULAR DISPLACEMENT OF A ROTATABLE BODY WITH RESPECT TO A REFERENCE BODY COMPRISING, AN ELONGATED SUPPORT ARM HAVING MEANS FOR SECURING SAID ARM TO A ROTATABLE BODY, A BUS BAR HAVING CONDUCTIVE ROLLERS ROTATABLY MOUNTED THEREON AND CONDUCTIVELY LINKED IN SERIES CIRCUIT TO SAID BUS BAR, SPRING MEANS INTERPOSED BETWEEN SAID SUPPORT ARM AND SAID BUS BAR FOR FLEXIBLY BIASING SAID BUS BAR AWAY FROM ONE SURFACE OF SAID SUPPORT ARM, CONTACT PLATE MEANS FIXEDLY MOUNTED ON A REFERENCE BODY RELATIVE TO SAID ROTATABLE BODY AND HAVING SPACED PAIRS OF CONDUCTIVE PADS SPACED AT ANGULAR INTERVALS WITH RESPECT TO A REFERENCE POSITION THEREON FOR SEPARATELY ENGAGING SAID ROLLES WHEN SAID ROLLERS ARE YIELDABLY URGED INTO INTIMATE CONTACT WITH SAID PLATE MEANS AND CAUSED TO ROLL THEREOVER UPON ROTATTION OF SAID ROTATABLE BODY, INDICATOR MEANS ELECTRICALLY COUPLED TO EACH PAIR OF SPACED PADS FOR INDICATING THE ANGULAR DISPLACEMENT OF SAID BODY WHEN SAID ROLLERS SHORT CIRCUIT SAID PAIRS OF PADS.