US 4,681,416 AGranted

Camera shutter cocking mechanism

AssigneeW. Haking Enterprises Limited

InventorKlaus Raschke

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Abstract

A camera shutter cocking system employs a specially configured cam driven synchronously with a film-engaging sprocket to actuate a shutter cocking lever from a released to a shutter cocking condition by means of a cam follower mounted on the cocking lever. The cam preferably has two lobes, each configured to maintain the shutter cocking load on an electric motor drive system generally constant throughout substantially the entire film advancing operation. Excessive terminal overspeed of the motor drive system is thereby suppressed. A one-way clutch between the cam and the sprocket disengages the shutter cocking system from the motor drive during rewind and traps the cocking lever in a released position, thus preventing multiple double exposure of the film if the shutter release button is accidentally held down by the user during this operation.

Claims12

Dependent claims

In a camera having a shutter release system, an electric motor drive system coupled to advance a film and actuate a shutter-cocking system from a released to a cocked condition with each one-frame advance of said film, said shutter-cocking system restoring said shutter release system to a cocked condition responsively to movement of a movable cocking member coupled to be driven by said motor drive system from a released to a shutter-cocking position against the opposing force of at least one energizing spring, said opposing force increasing with the movement of said cocking member from said released to said shutter-cocking position, the improvement comprising:

camming means rotatingly driven by said motor drive system and having at least one cam lobe with a contour of varying radius from the axis of rotation thereof;
cam follower means coupled to said cocking member and urged to engagingly follow said cam lobe so as to move said cocking member from said released to said shutter-cocking position against said increasing opposing force, said lobe contour being configured to maintain the load of said shutter cocking system on said motor drive system generally constant throughout film advance.

In a camera having shutter release means, a film advance and rewind drive means coupled to advance and rewind film and to actuate shutter-cocking means from a released to a cocked condition with each one-frame advance of said film, said shutter-cocking means restoring said shutter release means to a cocked condition responsively to movement of a movable cocking member coupled to said drive means to be driven from a released to a shutter-cocked position and including camming means coupled to said drive system to be rotatingly driven synchronously with film movement during film advance;

and cam follower means coupled to said cocking member and urged to engagingly follow said camming means so as to move said cocking lever from said released to said shutter-cocking position during movement of said camming means, the improvement comprising:
decoupling clutch means for decoupling said camming means from said drive means during rewind and latching means for lockingly immobilizing said camming means during rewind by lockingly engaging said camming means to said cam follower means so as to maintain said cocking member in said released position.

Dependencies are inferred from the claim text.