Mount arrangement and interchangeable lens unit for photographic camera

Claim 1

In a lens interchangeable photographic camera capable of automatic diaphragm control and including a bayonet mount device which is adapted to mount and demount an interchangeable lens unit to and from a camera body through predetermined angle clockwise rotation and counterclockwise rotation of said lens unit relative to said camera body as viewed from the front of said camera, respectively, a mount arrangement comprising: a lens unit mount member fixedly provided on said lens unit, and having bayonet claws formed at a rearmost portion of said lens unit and an annular mount face formed forwardly of said bayonet claws; a camera body mount member fixedly provided on said camera body, and having an annular mount face formed at a forwardmost portion of said camera body so as to be brought into contact with said mount face of said lens unit mount member with the mounting of said lens unit on said camera body completed and bayonet claws formed rearwardly of said mount face of said camera body mount member so as to be engageable with said bayonet claws of said lens unit mount member, said bayonet claws of said lens unit mount member and said bayonet claws of said camera body mount member constituting said bayonet mount device; a positioning recess formed on said mount face of said lens unit mount member at an immediate left side portion of said lens unit mount member as viewed from the rear of said lens unit with the mounting of said lens unit on said camera body completed; a positioning member provided on said mount face of said camera body mount member at an immediate right side portion of said camera body mount member and urged to project from said mount face of said camera body mount member for engaging said positioning recess with the mounting of said lens unit on said camera body completed; lens unit electrical contacts proviced along the inner peripheral side of the upper portion of said lens unit mount member with the mounting of said lens unit on said camera body completed and arranged rearwardly of said mount face of said lens unit mount member and forwardly of the rear faces of said bayonet claws of said lens unit mount member; camera body electrical contacts provided along the inner peripheral side of an upper portion of said camera body mount member and arranged rearwardly of said mount face of said camera body mount member so as to be brought into contact with said lens unit electrical contacts with the mounting of said lens unit on said camera body completed for signal transmission between said lens unit and said camera body: a diaphragm interlocked member for the automatic diaphragm control, provided at the inner peripheral side of a left side portion of said lens unit mount member as viewed from the rear of said lens unit with the mounting of said lens unit on said camera body completed and having a rear end portion arranged rearwardly of said mount face of said lens unit mount member and forwardly of said lens unit electrical contacts so as not to interfere with said camera body electrical contacts during the start and the course of the mounting of said lens unit on said camera body; and a diaphragm operating member for the automatic diaphragm control, provided at the inner peripheral side of a right side portion of said camera body mount member as viewed from the front of said camera body and having a front end arranged rearwardly of said mount face of said camera body mount member and forwardly of said electrical contacts for said camera body, said rear end portion of said diaphragm interlocked member and said front end portion of said diaphragm operating member being engageable with one another with the mounting of said lens unit on said camera body completed.