Rolling loop film transport mechanism

Claim 2

A film transport mechanism for a motion picture machine in which a film is intermittently transported through a predetermined frame length in relation to an aperture, said film transport mechanism comprising: a stator, a rotor cooperating with said stator to define a passage for said film, said rotor having gaps for receiving film loops; an inlet in said stator through which said film is fed into said passage; an outlet in said stator through which said film is withdrawn from aid passage, said aperture being intermediate said inlet and said outlet; film moving means for feeding said film into said inlet at a controlled speed relative to the speed of Said rotor and for withdrawal for said film from said outlet at said controlled speed; film locating means for cooperating with said film moving means for gradually increasing and then gradually decreasing said film loop in said gap and for intermittently holding said film in fixed position in registration with said aperture; and decelerating means coupled to said stator and operable to decelerate said film to thereby reduce impact between said film and said locating means as said film engages said locating means.

Claim 3

A film transport mechanism as claimed in claim 1 wherein said decelerating means is adjacent said aperture and wherein said decelerating means comprises: film engagement means for releasably engaging a film to decelerate said film and including cam follower means; cam means cooperating with said cam follower means for controlling the position of said engagement means; and drive means coupled to said rotor for driving said cam means through a cycle of movements, said cam means being in a predetermined position relative to said stator as each of said gaps reaches said aperture.

Claim 4

A film transport mechanism as claimed in claim 2 wherein said engagement means comprises; a cam follower, said cam follower being pivotally coupled to a stationary portion of said decelerating means; decelerating pins fixed to the distal end of said follower for engaging in perforations in said film, said pins being shaped to substantially eliminate interference between said film and said pins when said film engages and disengages said pins as a said loop is transported past said pins by a said rotor gap.

Claim 5

A film transport mechanism as claimed in claim 3 wherein said cam means comprises a cam wheel having a profiled groove for cooperating with said cam follower to move said decelerating pins through said cycle, said cycle comprising; advancing said pins to a position where said pins are freely engaged in perforations in said film, said pins then remaining stationary as said loop approaches and lifts said film off said pins; said pins are then moved toward the trailing side of said loop before their direction is reversed to move the pins in the locations of motion of said film, whereupon said film engages on said pins and said pins are decelerated thereby reducing the velocity of said film to reduce the impact of said film on said film locating means.

Claim 6

A film transport mechanism as claimed in claim 1 which further comprises: cushioning means coupled to said rotor and operable to reduce the impact between a growing loop and a trailing side of said gap as said rotor picks up said growing loop in said gap.

Claim 7

A film transport mechanism as claimed in claim 5 which further includes film stabilizing means, said film stabilizing means comprising: a pressurized gas supply; means distributing said supply to said stator intermediate said inlet and said aperture; gas jet means fixed to said stator and operably coupled to said distribution means, said gas jet means extending substantially between said inlet and said aperture for directing said gas against said film to thereby stabilize said film in said passage.

Claim 8

A film transport mechanism as claimed in claim 1 which further includes film stabilizing means, said film stabilizing means comprising: a pressurized gas supply; means distributing said supply to said stator intermediate said inlet and said aperture; gas jet means fixed to stator and operably coupled to said distribution means, said gas jet means extending substantially between said inlet and said aperture for directing said gas against said film to thereby stabilize said film in said passage.

Claim 9

A film transport mechanism as claimed in claim 7 wherein said film transport mechanism further comprises: a light source adapted to project light through said film in registration with said aperture; primary and secondary shutters fixed to said rotor for interrupting said projected light, each of said primary shutters bridging a said gap and each said secondary shutters beIng located midway between adjacent primary shutters to interrupt projection, each of said shutters having a predetermined circumferential extent about the periphery of said rotor; a plat fixed to said stator, said plate having a curved face forming a portion of the outer side of said film passage, said plate being positioned adjacent said outlet for cushioning the final collapse of said loop by controlling the direction of flow of air displaced by said loop; and wherein said rotor moves about generally vertical axis and said stator rotor further comprises a horizontal inwardly extending ledge, said film moving with the lower edge of said film on said ledge; and wherein said mechanism further comprises pressure means adapted to apply a downward force on the upper edge of said film to locate said film lower edge against said ledge.

Claim 10

A film transport mechanism for a motion picture machine in which a film is intermittently transported through a predetermined frame length in relation to an aperture, said film transport mechanism comprising: a stator; a rotor cooperating with said stator to define a passage for said film, said rotor having gaps for receiving film loops; an inlet in said stator through which said film is fed into said passage; an outlet in said stator through which said film is withdrawn from said passage said aperture being intermediate said inlet and said outlet; film moving means for feeding said film into said inlet at a controlled speed relative to the speed of said rotor and for withdrawal of said film from said outlet at said controlled speed; film locating means for cooperating with said film moving means for gradually increasing and then gradually decreasing said film loop in said gap and for intermittently holding said film in fixed position in registration with said aperture; and cushioning means coupled to said rotor and operable to reduce the impact between a growing loop and the trailing side of said gap as said rotor picks up said growing loop in said gap.

Claim 11

A film transport mechanism for a motion picture machine in which a film is intermittently transported through a predetermined frame length in relation to an aperture, said film transport mechanism comprising: a stator; a rotor cooperating with said stator to define a passage for said film, said rotor having gaps for receiving film loops; an inlet in said stator through which said film is fed into said passage; an outlet in said stator through which said film is withdrawn from said passage said aperture being intermediate said inlet and said outlet; film moving means for feeding said film into said inlet at a controlled speed relative to the speed of said rotor and for withdrawal of said film from said outlet at said controlled speed; film locating means for cooperating with said film moving means for gradually increasing and then gradually decreasing said film loop in said gap and for intermittently holding said film in fixed position in registration with said aperture; and cushioning means coupled to said rotor and operable to reduce the impact between a growing loop and the trailing side of said gap as said rotor picks up said growing loop in said gap.

Claim 12

A film transport mechanism as claimed in claim 9 wherein said cushioning means comprises: supply means coupled to said stator for selectively distributing a pressurized gas to said gaps so that each gap receives a pulse of gas as said gap receives a newly formed loop; and gas jet means directing said pressurized gas towards said loop to thereby cushion the impact of said trailing side of said gap on said loop.

Claim 13

A film transport mechanism as claimed in claim 10 wherein said supply means comprises: a fixed inlet pipe connected to a pressurized gas supply; a rotary union coupled to said inlet pipe and to said rotor; distribution pipes attached to said rotor and to said rotary union for distributing gas from said union to said gas jet means; and a valve coupled to said rotary union for supplying said gas to each of said distribution pipes in sequence.

Claim 14

A film transport mechanism as claimed in claim 11 wherein said supply means further comprises a plurality of secondary pipes for supplying said pressurized gas to said aperture to blow dust and the like off an aperture lens; each of said secondary pipes being coupled to s distribution pipe adjacent a said gap and extending forwardly about said rotor to a preceding gap for directing a proportion of said pulse of gas into said preceding gap to clean said lens.

Claim 15

A film transport mechanism as claimed in claim 9 which further includes film stabilizing means, said film stabilizing means comprising; a pressurized gas supply; means distributing said supply to said stator intermediate said inlet and said aperture; gas jet means fixed to stator and operably coupled to said distribution means, said gas jet means extending substantially between said inlet and said aperture for directing said gas against said film to thereby stabilize said film in said passage.

Claim 16

A film transport mechanism for a motion picture projector, said mechanism comprising: a. a generally cylindrical rotor having a plurality of gaps spaced equally about its periphery for receiving a film loop, b. a stator cooperating with said rotor to define a passage for guiding said film, said stator having an aperture for projecting said film, c. a film inlet at an inlet end of said passage for guiding film into said passageway, said film inlet being positioned at a predetermined circumferential distance from said aperture, said predetermined distance being substantially equal to the circumferential distance between adjacent gaps in said rotor, d. a film outlet end of said passage, the circumferential distance between said outlet and said aperture being substantially greater than said predetermined circumferential distance, e. means for moving said film through said passage from said inlet to said outlet in the direction of rotation of said rotor so that the time interval between successive gaps passing said aperture is substantially equal to the time taken by said film moving means to feed a film frame length into said passage; f. film locating means for cooperating with said film moving means for gradually increasing and then gradually decreasing said film loop in a said gap when a said gap is opposite said stator and for intermittently holding said film in fixed position in register with said aperture; g. a light source adapted to project light through said film in registration with said aperture; h. primary and secondary shutters fixed to said rotor for interrupting said projected light, each of said primary shutters bridging a said gap and each said secondary shutter being located midway between adjacent primary shutters to interrupt projection, each of said shutters having a predetermined circumferential extent about the periphery of said rotor, i. and a plate fixed to said stator, said plate having a curved face forming a portion of the outer side of said film passage, said plate being positioned adjacent said outlet for cushioning the final collapse of said loop by controlling the direction of flow of air displaced by said loop.

Claim 17

A film transport mechanism for a motion picture projector, said mechanism comprising: a. a generally cylindrical rotor having a plurality of gaps spaced equally about its periphery for receiving a film loop, b. a stator cooperating with said rotor to define a passage for guiding said film, said stator having an aperture for projecting said film, c. a film inlet at an inlet end of said passage for guiding film into said passageway, said film inlet being positioned at a predetermined circumferential distance from said aperture, said predetermined distance being substantially equal to the circumferential distance between adjacent gaps in said rotor, d. a film outlet end of said passage, the circumferential distance between said outlet and said aperture being substantially greater than said predetermined circumferential distance, e. means for moving said film through said passage from said inlet to said outlet in the direction of rotation of said rotor so that the time interval between successive gaps passing said aperture is substantially equal to the time taken by said film moving means to feed a film frame length into said passage; f. film locating means for cooperating with said film moving means for gradually increasing and then gradually decreasing said film loop in a said gap when a said gap is opposite said stator and for intermittently holding said film in fixed position in register with said aperture; g. a light source adapted to project light through said film in registration with said aperture; h. primary and secondary shutters fixed to said rotor for interrupting said projected light, each of said primary shutters bridging a said gap and each said secondary shutter being located midway between adjacent primary shutters to interrupt projection, each of said shutters having a predetermined circumferential extent about the periphery of said rotor, i. and a plate fixed to said stator, said plate having a curved face forming a portion of the outer side of said film passage, said plate being positioned adjacent said outlet for cushioning the final collapse of said loop by controlling the direction of flow of air displaced by said loop.

Claim 18

A film transport mechanism as claimed in claim 14 wherein said rotor moves about a generally vertical axis and said rotor further comprises a horizontal inwardly extending ledge, said film moving with the lower edge of said film on said ledge; and wherein said mechanism further comprises pressure means adapted to apply a downward force on the upper edge of said film to locate said film lower edge against said ledge.

Claim 19

A film transport mechanism as claimed in claim 14 which further comprises: a decelerating means coupled to said stator and operable to decelerate said film to thereby reduce impact between said film and said locating means as said film engages said locating means.

Claim 20

A film transport mechanism as claimed in claim 16 which further includes: cushioning means coupled to said rotor and operable to reduce the impact between a growing loop and the trailing side of said gap as said rotor picks up said growing loop in said gap.

Claim 21

A film transport mechanism as claimed in claim 17 which further includes film stabilizing means, said film stabilizing means comprising: a pressurized gas supply; means distributing said supply to said stator intermediate said inlet and said aperture; gas jet means fixed to stator and operably coupled to said distribution means, said gas jet means extending substantially between said inlet and said aperture for directing said gas against said film to thereby stabilize said film in said passage.

Claim 22

A film transport mechanism as claimed in claim 14 which further includes: cushioning means coupled to said rotor and operable to reduce the impact between a growing loop and the trailing side of said gap as said rotor picks up said growing loop in said gap.

Claim 23

A film transport mechanism as claimed in claim 14 which further includes film stabilizing means, said film stabilizing means comprising: a pressurized gas supply; means distributing said supply to said stator intermediate said inlet and said aperture; gas jet means fixed to stator and operably coupled to said distribution means, said gas jet means extending substantially between said inlet and said aperture for directing said gas against said film to thereby stabilize said film in said passage.

Claim 24

A film transport mechanism as claimed in claim 14 wherein said film locating means comprises at least one stationary pin fixed to said stator adjacent said aperture, said pin being adapted for engaging film perforations to locate said frame at said aperture.

Claim 25

A film transport mechanism as claimed in claim 21 wherein said rotor moves about a generally vertical axis and said rotor further comprises a horizontal inwardly extending ledge, said film moving with the lower edge of said film on said ledge; and wherein said mechanism further comprises pressure means adapted to apply a downward force on the upper edge of said film to locate said film lower edge against said ledge.

Claim 26

A film transport mechanism as claimed in claim 22 wherein said film locating means further comprises vacuum means coupled to said stator about said aperture for drawing said film into engagement with the periphery of said aperture.

Claim 27

A film transport mechanism as claimed in claim 23 wherein said rotor has eight said gaps and said film moving means includes an inlet sprocket for feeding said film into said inlet and an outlet sprocket for drawing said film from said outlet, said sprockets being adapted to move eight frame lengths of film for each revolution of said rotor.

Claim 28

A film transport mechanism for a motion picture projector, said mechanism comprising: a. a generally cylindrical rotor having a plurality of gaps spaced equally about its periphery for receiving a film loop, b. a stator cooperating with said rotor to define a passage for guiding said film, said stator having an aperture for projecting said film, c. a film inlet at an inlet end of said passage for guiding film into said passageway, said film inlet being positioned at a predetermined circumferential distance from said aperture, said predetermined distance being substantially equal to the circumferential distance between adjacent gaps in said rotor, d. a film outlet at an outlet end of said passage, the circumferential distance between said outlet and said aperture being substantially greater than said predetermined circumferential distance, e. means for moving said film through said passage from said inlet to said outlet in the direction of rotation of said rotor so that the time interval between successive gaps passing said aperture is substantially equal to the time taken by said film moving means to feed a film frame length into said passage; f. film locating means for cooperating with said film moving means for gradually increasing and then gradually decreasing said film loop in a said gap when a said gap is opposite said stator and for intermittently holding sad film in fixed position in register with said aperture; g. a light source adapted to project light through said film in registration with said aperture; h. primary and secondary shutters fixed to said rotor for interrupting said projected light, each of said primary shutters bridging a said gap and each said secondary shutters being located midway between adjacent primary shutters to interrupt projection, each of said shutters having a predetermined circumferential extent about the periphery of said rotor, i. and film stabilizing means, said film stabilizing means comprising: a pressurized gas supply; means distributing said supply to said stator intermediate said inlet and said aperture; gas jet means fixed to stator and operably coupled to said distribution means, said gas jet means extending substantially between said inlet and said aperture for directing said gas against said film to thereby stabilize said film in said passage.

Claim 29

A film transport mechanism for a motion picture projector, said mechanism comprising: a. a generally cylindrical rotor having a plurality of gaps spaced equally about its periphery for receiving a film loop, b. a stator cooperating with said rotor to define a passage for guiding said film, said stator having an aperture for projecting said film, c. a film inlet at an inlet end of said passage for guiding film into said passageway, said film inlet being positioned at a predetermined circumferential distance from said aperture, said predetermined distance being substantially equal to the circumferential distance between adjacent gaps in said rotor, d. a film outlet at an outlet end of said passage, the circumferential distance between said outlet and said aperture being substantially greater than said predetermined circumferential distance, e. means for moving said film through said passage from said inlet to said outlet in the direction of rotation of said rotor so that the time interval between successive gaps passing said aperture is substantially equal to the time taken by said film moving means to feed a film frame length into said passage; f. film locating means for cooperating with said film moving means for gradually increasing and then gradually decreasing said film loop in a said gap when a said gap is opposite said stator and for intermittently holding sad film in fixed position in register with said aperture; g. a light source adapted to project light through said film in registration with said aperture; h. primary and secondary shutters fixed to said rotor for interrupting said projected light, each of said primary shutters bridging a said gap and each said secondary shutters being located midway between adjacent primary shutters to interrupt projection, each of said shutters having a predetermined circumferential extent about the periphery of said rotor, i. and film stabilizing means, said film stabilizing means comprising: a pressurized gas supply; means distributing said supply to said stator intermediate said inlet and said aperture; gas jet means fixed to stator and operably coupled to said distribution means, said gas jet means extending substantially between said inlet and said aperture for directing said gas against said film to thereby stabilize said film in said passage.