MAGNETICALLY DRIVEN PHOTOGRAPHIC SHUTTER WITH BRAKING

• US 3,604,330 A
• Filed: 09/04/1968
• Issued: 09/14/1971
• Est. Priority Date: 09/19/1967
• Status: Expired due to Term

• Current Assignee: Paul Fahlenberg, Walter Ruppelt
• Original Assignee: Paul Fahlenberg, Walter Ruppelt
• Inventors: Ruppelt, Walter, Fahlenberg, Paul
• Primary Examiner(s): Matthews, Samuel S.
• Assistant Examiner(s): Gellner, M. L.
• Application Number:
  US04/757,362
• Time in Patent Office: 1,105 Days
• Field of Search: 95/12,5,31,53,58,59,62,63
• US Class Current: 396/455
• CPC Class Codes: G03B 9/58 Means for varying duration of "open" period of shutter

Abstract

A photographic camera shutter arrangement includes first and second magnetic windings which respectively control the opening and closing movements of the shutter blades. The windings are pulse-energized, the interval between the energization of the first winding by a first control pulse and of the second winding by a second control pulse determining the exposure time of the shutter. A braking pulse applied after a control pulse is applied to a winding other than that to which the control pulse is applied retards movement of the shutter blades in the direction dictated by the control pulse so that '"'"''"'"''"'"''"'"'bouncing'"'"''"'"''"'"''"'"' or rebounding of the shutter blades is reduced.

Claims

1. Photographic camera apparatus including a shutter arrangement comprising at least one movable shutter member, pulse-actuated magnetic means for controlling the movement of the shutter member in at least a first direction, and pulse-producing means for controlling actuation of said magnetic means, wherein the improvement comprises magnetic means for producing a retarding force on the movement of the shutter arrangement which acts in a direction opposite to the first direction of movement of the shutter member, said retarding force producing magnetic means comprising further pulse-actuated means for controlling movement of said shutter member in a second direction, and said magnetic means for controlling movement of this shutter member in a first direction being controlled to produce a retarding force on the movement of the shutter member initiated by said further pulseactuated means.

2. Photographic camera apparatus as claimed in claim 1 wherein the first-mentioned magnetic means comprises a first magnetic winding for controlling the opening movement of said shutter member, said further magnetic means comprises a second magnetic winding for controlling the closing movement of said shutter member, and said first and second pulse-producing means comprises electronic means for producing a first pulse for energizing said first magnetic winding and a second pulse for energizing said second magnetic winding, the interval between said pulses determining the open time of said shutter, said electronic means further comprising means for applying a braking pulse to one of said first and second windings when an energizing pulse is applied to another of said first and second windings.

3. Photographic camera apparatus including a shutter arrangement comprising at least one movable shutter member, a first magnetic winding for driving the shutter member in a first direction for opening said shutter member, a second magnetic winding for driving said shutter member in a second direction for closing said shutter member, pulse-producing electronic means for controlling actuation of said first and second magnetic windings, said electronic means including means for applying a braking pulse to said second winding after a control pulse is applied to said first winding and for applying a braking pulse to said first winding after a control pulse is applied to said second winding.

4. Photographic camera apparatus including a shutter arrangement comprising at least one movable shutter member, a first magnetic winding for driving the shutter member in a first direction for opening said shutter member, a second magnetic winding for driving said shutter member in a second direction for closing said shutter member, pulse-producing electronic means for controlling actuation of said second magnetic winding, said electronic means comprising means for transmitting a control pulse to one of said windings and for transmitting a braking pulse to said one of said windings when said control pulse is applied to said one winding, said braking pulse comprising a delayed version of said control and the duration of said delayed pulse being short as compared with said control pulse.

5. Photographic camera apparatus including a shutter arrangement comprising at least one movable shutter member, a first magnetic winding for driving the shutter member in a first direction for opening said shutter member, first pulse-producing electronic means for controlling actuation of said first magnetic winding, a second magnetic winding for driving said shutter member in a second direction for closing said shutter member, secOnd pulse-producing electronic means for controlling actuation of said second magnetic winding, said first pulse-producing means producing, upon the production of a pulse for initiating movement of said shutter member by said second-pulse producing means, a pulse for actuating said first magnetic means to produce a retarding force on the movement of said shutter member which acts in said first direction and hence retards movement of said shutter member in said second direction.