Exposure time controls for cameras

Claim 1

In a camera, an electrical structure for initiating closing of a camera shutter to determine the exposure time, said electrical structure including an electromagnet having a core, an armature, and a coil surrounding said core, said core having an elongated portion of a given diameter surrounded by said coil and having a tapered end portion terminating in a flat end face and having its maximum diameter next to said elongated portion of said core which is surrounded by said coil and its minimum diameter at said flat face, said maximum diameter of said tapered end portion equalling the diameter of said elongated core portion which is surrounded by said coil, said armature being situated adjacent and coacting with said flat end face of said core, adjusting means operatively connected with said armature for inclining the latter at a selected angle with respect to said flat face, a train of motion-transmitting elements operatively connected with said armature for transmitting motion thereto for displacing the latter away from said flat end face of said core to initiate shutter-closing operations, said adjusting means being operatively connected with said armature for positioning the latter with respect to said flat end face of said core at a location which will achieve high-speed mechanical operation for short exposure times, and a trailing curtain of a focal plane shutter operatively connected to said train of elements for driving the latteR when the electrical structure releases said armature for movement away from said flat end face of said core, said train of motion-transmitting elements including one motiontransmitting element coacting with said armature for transmitting its motion thereto, and said armature being supported for swinging movement toward and away from said flat end face of said core, said adjusting means being operatively connected with said armature for adjusting the latter with respect to said one motion-transmitting element.