Shutter control for photographic camera apparatus

Abstract

This invention is directed to the control of a camera shutter mechanism by means of a pair of resilient control members. A first control member in the form of a fast acting spring is attached to the camera base member and, with operation initiates at a relatively low speed to provide an initial movement of the shutter control and overcomes the inertia of the mechanism and initiates its movement from a state of rest. This effect is preferably followed by a second effect provided by a second driving spring to achieve a substantially uniform movement of the mass of the mechanism first actuated, with the second driving spring acting continuously, following the initial operation, upon the shutter mechanism after a change from a rest position to one of movement. The first spring used to overcome the inertia of the mass of the operation, and effective only for the initial operation, is one which is heavy relative to the second spring and is arranged to initiate operation and transfer the drive from a cocked shutter position to control by the second spring which is much weaker but adequate to insure a substantially uniform movement of the mass of the shutter control which is active continuously for the desired shutter aperture opening period. A single control device is used to initiate the entire operation and to effect the sequential spring control.

Dependencies are inferred from the claim text.