Focal plane shutter for cameras

Claim 1

IN A FOCAL PLANE SHUTTER OF THE TYPE HAVING FIRST AND SECOND RIGID CURTAIN ELEMENTS MOVED BETWEEN COCKED AND EXPOSED POSITIONS ACROSS AN EXPOSURE APERTURE IN A SHUTTER BASE PLATE BY FIRST AND SECOND ACTUATING LEVERS, RESPECTIVELY; A SHUTTER ACTUATING MECHANISM INCLUDING FIRST AND SECOND MAIN SPRINGS SEVERALLY CONNECTED WITH SAID ACTUATING LEVERS FOR DRIVING SAID RESPECTIVE ELEMENTS ACROSS THE EXPOSURE APERTURE WITHOUT DISTURBING THE ADJUSTED EXPOSURE TIME, FIRST AND SECOND LATCH MEMBERS HOLDING EACH SAID ACTUATING LEVER AGAINST ITS MAIN SPRING AT THE SHUTTER COCKED POSITION, FIRST AND SECOND HOOK LEVERS SEVERALLY PIVOTED ON SAID ACTUATING LEVERS, A ROTATABLE ASSEMBLAGE OF FIRST AND SECOND RELATIVELY ANGULARLY DISPLACEABLE CAM CYLINDERS INCLUDING CAM SURFACES OPERATIVELY ENGAGING SAID ACTUATING LEVERS, AN EXPOSURE PREVENTING DEVICE TO PREVENT EXPOSURE DURING THE COCKING OF THE SHUTTER, A FIRST AND A SECOND LATCH OPERATING MEANS PIVOTED ON THE SHUTTER BASE PLATE AND ENGAGED SEVERALLY WITH SAID FIRST AND SECOND CAM CYLINDERS IN SUCH A MANNER THAT WHEN SAID CYLINDERS ARE ROTATED IN COCKING THE SHUTTER, SAID FIRST AND SECOND LATCH OPERATING MEANS MOVE SAID HOOK LEVERS SIMULTANEOUSLY ON SAID EXPOSURE PREVENTING DEVICE UNTIL SAID ACTUATING LEVERS ENGAGE SAID LATCH MEMBERS AT THE SHUTTER COCKED POSITION, AND WHEN SAID CYLINDERS ARE ROTATED REVERSELY IN THE SHUTTER RELEASING THESE LATCH OPERATING MEANS RELEASE SAID ACTUATING LEVERS FROM SAID LATCH MEMBERS IN SUCCESSION AS DETERMINED BY THE ANGULAR DISPLACEMENT BETWEEN SAID CYLINDERS.