Diaphragm operating structure for cameras

Claim 1

IN A CAMERA, IN COMBINATION, A CAMERA HOUSING; AN OBJECTIVE ASSEMBLY CARRIED BY SAID CAMERA HOUSING AND INCLUDING A REAR SECTION PERMANENTLY CONNECTED WITH SAID CAMERA HOUSING AND A FRONT SECTION REMOVABLY CONNECTED TO SAID REAR SECTION SO THAT SAID FRONT SECTION OF SAID OBJECTIVE ASSEMBLY MAY BE EXCHANGED FOR ANOTHER FRONT SECTION; A DIAPHRAGM AND A DIAPHRAGM SETTING MEANS CARRIED BY SAID FRONT SECTION OF SAID OBJECTIVE ASSEMBLY; DEPTH OF FIELD INDICATING MEANS ALSO CARRIED BY SAID FRONT SECTION OF SAID OBJECTIVE ASSEMBLY; PRESELECTING MEANS CARRIED BY SAID REAR SECTION OF SAID OBJECTIVE ASSEMBLY FOR PRESELECTING THE SETTING OF THE DIAPHRAGM, SAID PRESELECTING MEANS BEING OPERATIVELY CONNECTED TO SAID DEPTH OF FIELD INDICATING MEANS FOR ACTUATING THE LATTER TO INDICATE THE DEPTH OF FIELD CORRESPONDING TO THE DIAPHRAGM SETTING PRESELECTED BY SAID PRESELECTING MEANS; DRIVE MEANS OPERATIVELY CONNECTED TO SAID DIAPHRAGM SETTING MEANS FOR DRIVING THE LATTER TO SET THE DIAPHRAGM AT THE SETTING PRESELECTED BY SAID PRESELECTING MEANS; AND SHUTTER ACTUATING MEANS FOR ACTUATING THE SHUTTER OF THE CAMERA TO MAKE AN EXPOSURE, SAID SHUTTER ACTUATING MEANS ACTUATING SAID DRIVE MEANS FOR DRIVING SAID DIAPHRAGM SETTING MEANS TO THE PRESELECTED SETTING JUST PRIOR TO OPENING OF THE SHUTTER TO MAKE THE EXPOSURE, WHEREBY THE DEPTH OF FIELD WILL BE INDICATED AS SOON AS SAID PRESELECTING MEANS PROVIDES THE PRESELECTED SETTING OF THE DIAPHRAGM AND BEFORE THE DIAPHRAGM IS ACTUALLY SET AT THE PRESELECTED SETTING.