Remotely controlled focal plane shutter

Claim 2

A focal plane shutter device comprising a format area in which photographic film is exposed, two pairs of rollers, each of said pair of rollers including a driving roller on one side and a follower roller on the other side of said format area, first and second curtains having ends which are separated by a distance defining an exposure slit, each of said curtains being mounted on an individually associated one of said pair of rollers by being aTtached at one end to a driving roller and at the other end to a follower roller, tensioning means independently connecting each of said driving rollers to its associated follower roller for restraining the movement of said follower rollers and precluding slack in said curtains, said tensioning means comprising substantially nonelastic tape means individually connected between each of said driving rollers and the associated follower rollers, and adjustable tension means for connecting said tape means to said associated follower rollers, and driving means for rotating said two driving rollers simultaneously at equal speeds for moving said curtains across said format area, said driving means comprising motor means selectively coupled to a differential means, said differential means being coupled to said driving rollers to thereby effect alternate bidirectional rotation of said driving rollers, and means responsive to operation of said differential for adjusting the width of said slit by selectively rotating of one of said driving rollers with respect to the other.

Claim 3

The shutter device of claim 1 wherein said means for selectively coupling said motor to said differential comprises first selectively actuatable clutch and brake mechanisms connected to one side of said differential means, and second selectively actuatable clutch and brake mechanism connected to the other side of said differential means.

Claim 4

The shutter device of claim 1 and means comprising a universal pivot in at least one of said rollers to compensate for variations in the points at which said shutter curtains are attached to their respective rollers.

Claim 5

The shutter device of claim 1 further comprising control means connected to said driving rollers and operated in a specific spatial relationship with respect to opposing edges of said shutter curtains, and electrical switching means operated responsive to said last-named control means for setting the limits of curtain travel.

Claim 6

The shutter device of claim 1 further comprising electromagnetic coupling means for interconnecting the two driven rollers associated with said pair of curtains to preclude variations in slit width responsive to backlash in said driving means.

Claim 7

In a focal plane shutter assembly having a pair of overlapping shutter curtains with rectangular openings disposed therein to form an exposure slit between a pair of opposing edges of said curtains, said curtains being wound upon individually associated rollers suitably mounted on opposite sides of said format areas, the improvement therein comprising: a first pair of said rollers positioned parallel to and on opposite sides of said format area and operatively associated with an outer one of said shutter curtains, said first pair of rollers comprising a first driving roller and a first follower roller; a second pair of said rollers operatively associated with an inner one of said shutter curtains and comprising a second driving roller and a second follower roller, each of said second pair of rollers positioned parallel to a corresponding one of said first pair of rollers but between it and said format area; tensioning means connected between each of said driving rollers and its associated follower roller to restrain the movement of said follower roller and to remove slack from the shutter curtain attached thereto, said tensioning means including substantially nonelastic flexible tape means connected to each of said driving rollers and adjustable spring means connecting said tape means to said associated follower rollers; and driving means for moving said curtains simultaneously and at equal speeds across said format area, said driving means comprising first and second gear trains coupled, respectively, to said first and second driving rollers, differential means having opposite sides connected, respectively, to said first and second gear trains, selectively actuatable clutch means coupled to said differential means, motor means alternately coupled to Said opposite sides of said differential means through said clutch means, and selectively actuatable brake means coupled to said driving rollers.

Claim 8

In a focal plane shutter assembly having a pair of overlapping shutter curtains with rectangular openings disposed therein to form an exposure slit between a pair of opposing edges of said curtains, said curtains being wound upon individually associated rollers suitably mounted on opposite sides of said format areas, the improvement therein comprising: a first pair of said rollers positioned parallel to and on opposite sides of said format area and operatively associated with an outer one of said shutter curtains, said first pair of rollers comprising a first driving roller and a first follower roller; a second pair of said rollers operatively associated with an inner one of said shutter curtains and comprising a second driving roller and a second follower roller, each of said second pair of rollers positioned parallel to a corresponding one of said first pair of rollers but between it and said format area; tensioning means connected between each of said driving rollers and its associated follower roller to restrain the movement of said follower roller and to remove slack from the shutter curtain attached thereto, said tensioning means including substantially nonelastic flexible tape means connected to each of said driving rollers and adjustable spring means connecting said tape means to said associated follower rollers; and driving means for moving said curtains simultaneously and at equal speeds across said format area, said driving means comprising first and second gear trains coupled, respectively, to said first and second driving rollers, differential means having opposite sides connected, respectively, to said first and second gear trains, selectively actuatable clutch means coupled to said differential means, motor means alternately coupled to Said opposite sides of said differential means through said clutch means, and selectively actuatable brake means coupled to said driving rollers.

Claim 9

The improvement in a focal plane shutter assembly as set forth in claim 6 wherein one roller in each of said first and second pairs of rollers comprises: an inner shaft portion and an outer sleeve portion concentric therewith, said sleeve portion comprising a first sleeve section and a second sleeve section pivotally joined therewith, and universal pivot means in at least said one roller for compensating for the differences in spacing between the points where said shutter curtains are attached to their respective rollers, said universal pivot means comprising a T-shaped coupling member having a shank portion pivotally positioned in said inner shaft portion of said roller and a head portion pivotally joining said sleeve sections of said roller together.

Claim 10

The focal plane shutter assembly of claim 6 and antibacklash means interconnecting said first and second driving rollers for precluding slit width variations responsive to backlash in said gear trains.

Claim 11

A focal plane shutter assembly comprising a pair of independently mounted curtains having edges separated by a predetermined amount to form an exposure slit, each of said curtains being wound upon an individually associated pair of rollers for bidirectionally transporting said slit across a predetermined exposure area, means for applying rotary power via a gear train to at least one of said rollers for moving said slit across said area, and means for interconnecting at least one roller associated with each of said curtains for substantially eliminating backlash in said gear train.

Claim 12

A focal plane shutter assembly comprising a pair of independently mounted curtains having edges separated by a predetermined amount to form an exposure slit, each of said curtains being wound upon an individually associated pair of rollers for bidirectionally transporting said slit across a predetermined exposure area, means for applying rotary power via a gear train to at least one of said rollers for moving said slit across said area, and means for interconnecting at least one roller associated with each of said curtains for substantially eliminating backlash in said gear train.

Claim 13

The assembly of claim 9 and a plurality of separate electromechanical means for selectively applying said rotary power and completing said interconnection, and means for operating each of said electromechanical means in a predetermined sequence to adjust the width of said slit and thereafter preserve said adjustment during the transportation of said curtains.