Rotary file with photoelectric switch selector

Claim 1

A CONTROL UNIT FOR SELECTIVELY POSITIONING A ROTATABLE DEVICE HAVING A FINITE NUMBER OF SELECTABLE POSITIONS, SAID UNIT COMPRISING ROTATABLE SHAFT MEANS ADAPTED TO BE COUPLED TO SAID ROTATABLE DEVICE, POWER MEANS FOR DRIVING SAID ROTATABLE DEVICE AND SAID SHAFT MEANS, A HOUSING SURROUNDING PART OF SAID SHAFT MEANS, A PLURALITY OF ENERGIZABLE RADIANT ENERGY EMITTERS DISPOSED IN CIRCUMFERENTIALLY SPACED RELATION AROUND SAID SHAFT MEANS, SAID EMITTERS BEING SUBSTANTIALLY ISOLATED EXCEPT FOR A LEAST ONE APERTURE ASSOCIATED WITH EACH EMITTER CORRESPONDING TO SAID POSITIONS, SAID APERTURES BEING DISPOSED ON A GIVEN FACE OF SAID HOUSING, SWITCHING MEANS FOR SELECTIVELY ENERGIZING SAID RADIANT ENERGY SOURCES, MEANS INCLUDING TWO PRIMARY RADIANT ENERGY RECEIVERS SPACED FROM SAID HOUSING FOR CONTROLLING SAID POWER MEANS IN RESPONSE TO RADIANT ENERGY INCIDENT UPON SAID RECEIVERS, AND A RADIANT ENERGY CONTROL MEMBER COUPLED TO SAID SHAFT MEANS, SAID RADIANT ENERGY CONTROL MEMBER BEING DISPOSED IN THE PATH OF ENERGY TRAVELING BETWEEN AN ENERGIZED SOURCE AND SAID RECEIVERS AND HAVING ENERGY TRANSMITTING AND BLOCKING SECTORS SUCH THAT ENERGY IS CUT OFF FROM SAID PRIMARY RECEIVERS WHEN A SELECTED POSITION IS REACHED.