Shutter timing apparatus

Claim 1

A SHUTTER MECHANISM FOR A CAMERA HAVING A HOUSING AND AN EXPOSURE APERTURE, COMPRISING: (A) A SHUTTER BLADE MOVABLE ON SAID HOUSING AND HAVING A BLOCKING TERMINAL POSITION AND AN UNBLOCKING TERMINAL POSITION RELATIVE TO SAID EXPOSURE APERTURE FOR CONTROLLING THE PASSAGE OF INCIDENT LIGHT THERETHROUGH; (B) BIAS MEANS ASSOCIATED WITH SAID SHUTTER BLADE FOR URGING THE SAME TOWARD ITS BLOCKING TERMINAL POSITION; (C) KEEPER MEANS ON SAID SHUTTER BLADE; (D) A SOLENOID OPERABLY ASSOCIATED WITH A POLE PIECE AND SO MOUNTED ON SAID HOUSING THAT THE ENGAGEMENT OF SAID KEEPER MEANS WITH SAID POLE PIECE DEFINES THE UNBLOCKING TERMINAL POSITION OF SAID BLADE AND COMPLETES THEREWITH A MAGNETIC CIRCUIT SUCH THAT ENERGIZATION OF SAID SOLENOID IS EFFECTIVE TO CREATE A MAGNETIC FORCE ON SAID KEEPER SUFFICIENT TO MAINTAIN SAID SHUTTER BLADE IN ITS UNBLOCKING TERMINAL POSITION AGAINST THE ACTION OF THE BIAS MEANS ASSOCIATED THEREWITH; (E) MANUALLY OPERABLE MEANS FOR MOVING SAID BLADE TO ITS UNBLOCKING TERMINAL POSITION AGAINST THE ACTION OF SAID BIAS MEANS; (F) FIRST MEANS RELEASABLY ENGAGEABLE WITH SAID BLADE WHEN THE LATTER IS IN UNBLOCKING TERMINAL POSITION FOR RELEASABLY RETAINING SAID BLADE IN UNBLOCKING TERMINAL POSITION PRIOR TO ENERGIZATION OF SAID SOLENOID; (G) AN ELECTRICAL CIRCUIT OPERABLE TO ENERGIZE SAID SOLENOID FOR A PERIOD OF TIME DEPENDING UPON AT LEAST ONE VARIABLE ELECTRICAL PARAMETER; (H) MEANS TO OPERATE SAID ELECTRICAL CIRCUIT AND DISENGAGE SAID FIRST MEANS FROM SAID BLADE SUBSTANTIALLY AT THE SAME TIME WHEREBY SAID SOLENOID IS EFFECTIVE TO MAINTAIN SAID BLADE IN UNBLOCKING TERMINAL POSITION UNTIL SAID SOLENOID IS DEENERGIZED AFTER WHICH RELEASE OF SAID BLADE IS EFFECTED AND THE LATTER MOVES TO ITS BLOCKING TERMINAL POSITION UNDER THE ACTION OF SAID BIAS MEANS; AND (I) MEANS TO AUTOMATICALLY DEENERGIZE SAID SOLENOID AFTER A PRESELECTED PERIOD OF TIME INDEPENDENTLY OF SAID VARIABLE ELECTRICAL PARAMETER WHEREBY SAID PRESELECTED PERIOD OF TIME REPRESENTS THE LONGEST TIME THAT SAID SOLENOID CAN BE ENERGIZED.