Photographic lens shutter mechanism

Claim 1

A PHOTOGRAPHIC LENS SHUTTER MECHANISM COMPRISING A SHUTTER CASING HAVING AN APERTURE, A SET OF SHUTTER BLADES, MOVABLE MEANS MOUNTING SAID SHUTTER BLADES UPON SAID CASING FOR CAUSING THEM TO DEFINE BETWEEN ADJACENT EDGES AN APERTURE OPENING OF VARIABLE SIZE, RESILIENT BIASING MEANS REACTING AGAINST SAID BLADES IN A DIRECTION TO CLOSE THEM, BLADE-DRIVING MEANS MOUNTED UPON SAID CASING IN OPERATIVE ENGAGEMENT WITH SAID SET OF SHUTTER BLADES FOR IMPARTING AN OPENING IMPULSE TO SAID BLADES, SAID BLADE-DRIVING MEANS DELIVERING FASTER IMPULSES OF SHORTER DURATION AND SLOWER IMPULSES OF LONGER DURATION, CONTROL MEANS CONNECTED TO SAID SHUTTER-DRIVING MEANS FOR VARYING THE SPEED OF DELIVERY OF SAID IMPULSES, MOTION-LIMITING MEANS MOUNTED IN THE PATH OF OPENING MOVEMENT OF SAID SET OF BLADES FOR DETERMINING A LIMIT THEREOF WHEREBY THE APERTURE OPENING DEFINED BY SAID BLADES IS MADE SUBSTANTIALLY PRECISE, MOVABLE MEANS MOUNTING SAID MOTION-LIMITING MEANS UPON SAID CASING FOR PERMITTING SAID APERTURE OPENING PROVIDED THEREBY TO BE VARIED, RESILIENT MEANS BIASING SAID MOTION-LIMITING MEANS TO MOVE TOWARD POSITIONS DEFINING LARGER APERTURE OPENINGS, AND A COORDINATING MEANS CONNECTING SAID MOTION - LIMITING MEANS WITH SAID SHUTTER-DRIVING MEANS FOR CAUSING SAID MOTION-LIMITING MEANS TO COMMENCE MOVEMENT IN A DIRECTION PROVIDING LARGER APERTURE OPENINGS WHEN SAID SHUTTER-DRIVING MEANS COMMENCE ITS MOVEMENT WHEREBY SAID MOTION-LIMITING MEANS IS CAUSED TO DEFINE LARGER APERTURE OPENINGS FOR SAID SET OF SHUTTER BLADES THE SLOWER AND LONGER THE DURATION OF THEIR OPENING MOVEMENT.