Transporting mechanism for motion picture film

Claim 2

In a cinematographic apparatus for use with film having a row of perforations, a combination comprising reversible drive means; and film transporting means comprising a shuttle having filmadvancing claw means, first and second cams rotatable by said drive means and respectively having first and second cam portions arranged to move said claw means in and counter to the normal direction of film transport as well as to compensate for clearances between said claw means and the perforations, selector means operable to maintain said shuttle in engagement with one of said cams at a time so that thE shuttle respectively receives motion from said first and second cams when said drive means respectively rotates in a first and a second direction, electromagnet means having energized and deenergized conditions and arranged to effect movements of said claw means into and away from adjoining perforations in response to changes in the condition thereof, and control means for changing the condition of said electromagnet means in synchronism with rotation of that cam which moves said shuttle.

Claim 3

A combination as defined in claim 1, wherein said electromagnet means is arranged to effect movements of said claw means into the adjoining perforations in response to energization thereof.

Claim 4

A combination as defined in claim 1, wherein said cams are angularly offset with reference to each other through a predetermined angle and said control means comprises a rotary control member driven by said drive means and rotatable with reference to said drive means through an angle corresponding to said predetermined angle.

Claim 5

A combination as defined in claim 3, wherein said control means further comprises switch means in circuit with said electromagnet means and actuating means provided on said control member and operative to actuate said switch means in response to rotation of said control member to thereby intermittently change the condition of said electromagnet means.

Claim 6

A combination as defined in claim 1, wherein said cams are angularly offset with reference to each other through a predetermined angle and said control means comprises first and second control members driven by said drive means and angularly offset with reference to each other through said predetermined angle.

Claim 7

A combination as defined in claim 1, wherein said cams are angularly offset with reference to each other through a predetermined angle and said control means comprises a rotary control member driven by said drive means and rotatable with reference to said drive means through said predetermined angle and control switch means in circuit with said electromagnet means and indirectly actuated by said control member to change the condition of said electromagnet means in synchronism with movements of said shuttle under the action of said first and second cams when said drive means respectively rotates said control member in said first and second directions.

Claim 8

A combination as defined in claim 6, wherein said control switch means comprises stationary first contact means and rotary second contact means receiving motion from said control member.

Claim 9

A combination as defined in claim 1, further comprising a gate and means for inactivating said control means so as to permit the retention of a selected film frame in registry with said gate for desired periods of time, and shutter means driven by said drive means and having vane means travelling along a path a portion of which is located in front of said gate.

Claim 10

A combination as defined in claim 8, further comprising heat-protecting filter means and means for moving said filter means into registry with said gate in response to inactivation of said control means.

Claim 11

A combination as defined in claim 9, wherein said cinematographic apparatus is a motion picture projector having a light source and said filter means is movable between said light source and the film frame in said gate.

Claim 12

A combination as defined in claim 10, wherein said means for moving said filter means comprises second electromagnet means in parallel with said first mentioned electromagnet means.

Claim 13

In a cinematographic apparatus for use with film having a row of perforations, a combination comprising a gate; reversible drive means; and film transporting means comprising a shuttle having film-advancing claw means, first and second cams rotatable by said drive means and respectively having first and second cam portions arranged to effect movements of said claw means in and counter to the normal direction of film transport; said cams being angularly offset with reference to each other through a predetermined angle, selector means operable to maintain said shuttle in engagement with one of said cams at a time so that the shuttle respectively receives motion from said first and second cams when said drive means respectively rotates in a first and second direction, electromagnet means having energized and deenergized conditions and arranged to effect movements of said claw means into and away from adjoining perforations in response to changes in the condition thereof, control means for changing the condition of said electromagnet means in synchronism with rotation of that cam which transmits motion to said shuttle, said control means comprising first and second control members driven by said drive means and angularly offset with reference to each other through said predetermined angle and first and second switches respectively adjacent to the paths of movement of and actuatable by said first and second control members, and means for respectively connecting said first and second control switches in circuit with said electromagnet means when said shuttle respectively receives motion from said first and second cams whereby the thus connected control switch changes the condition of said electromagnet means in synchronism with movements of the shuttle under the action of the respective cam.

Claim 14

In a cinematographic apparatus for use with film having a row of perforations, a combination comprising a gate; reversible drive means; and film transporting means comprising a shuttle having film-advancing claw means, first and second cams rotatable by said drive means and respectively having first and second cam portions arranged to effect movements of said claw means in and counter to the normal direction of film transport; said cams being angularly offset with reference to each other through a predetermined angle, selector means operable to maintain said shuttle in engagement with one of said cams at a time so that the shuttle respectively receives motion from said first and second cams when said drive means respectively rotates in a first and second direction, electromagnet means having energized and deenergized conditions and arranged to effect movements of said claw means into and away from adjoining perforations in response to changes in the condition thereof, control means for changing the condition of said electromagnet means in synchronism with rotation of that cam which transmits motion to said shuttle, said control means comprising first and second control members driven by said drive means and angularly offset with reference to each other through said predetermined angle and first and second switches respectively adjacent to the paths of movement of and actuatable by said first and second control members, and means for respectively connecting said first and second control switches in circuit with said electromagnet means when said shuttle respectively receives motion from said first and second cams whereby the thus connected control switch changes the condition of said electromagnet means in synchronism with movements of the shuttle under the action of the respective cam.

Claim 15

A combination as defined in claim 12, wherein said means for connecting said control switches in circuit with said electromagnet means comprises a multi-way switch.

Claim 16

A combination as defined in claim 13, wherein said multi-way switch is actuatable by said selector means.

Claim 17

In a cinematographic apparatus for use with film having a row of perforations, a combination comprising a gate; reversible drive means; and film transporting means comprising a shuttle having film-advancing claw means, first and second cams rotatable by said drive means and respectively having first and second cam portions arranged to effect movements of said claw means in and counter to the normal direction of film transport, said cams being angularly offset with reference to each other through a predetermined angle, selector means operable to maintain said shuttle in engagement with one of said cams at a time so that the shuttle respectively receives motion from said first and second cams when said drive means respectively rotates in a first and a second direction, electromagnet means having energized and deenergized conditions and arranged to effect movements of said claw means into and away from adjoining perforations in response to changes in the condition thereof, and control means for changing the condition of said electromagnet means in synchronism with rotation of that cam which transmits motion to said shuttle, said control means comprising a rotary control member driven by said drive means and rotatable with reference to said drive means through said predetermined angle and control switch means in circuit with said electromagnet means and indirectly actuated by said control member to change the condition of said electromagnet means in synchronizm with movements of said shuttle under the action rf said first and second cams when said drive means respectively rotates said control member in said first and second directions, said control switch means comprising stationary first contact means and rotary second contact means receiving motion from said control member, said stationary first contact means comprising first and second fixed contacts and said rotary contact means being connected with one terminal of said electromagnet means and being intermittently engaged by said fixed contacts in response to rotation thereof, said selector means comprising means for connecting a selected fixed contact with the other terminal of said electromagnet means whenever the selected fixed contact is engaged by and disengaged from said rotary contact means.

Claim 18

In a cinematographic apparatus for use with film having a row of perforations, a combination comprising a gate; reversible drive means; and film transporting means comprising a shuttle having film-advancing claw means, first and second cams rotatable by said drive means and respectively having first and second cam portions arranged to effect movements of said claw means in and counter to the normal direction of film transport, said cams being angularly offset with reference to each other through a predetermined angle, selector means operable to maintain said shuttle in engagement with one of said cams at a time so that the shuttle respectively receives motion from said first and second cams when said drive means respectively rotates in a first and a second direction, electromagnet means having energized and deenergized conditions and arranged to effect movements of said claw means into and away from adjoining perforations in response to changes in the condition thereof, and control means for changing the condition of said electromagnet means in synchronism with rotation of that cam which transmits motion to said shuttle, said control means comprising a rotary control member driven by said drive means and rotatable with reference to said drive means through said predetermined angle and control switch means in circuit with said electromagnet means and indirectly actuated by said control member to change the condition of said electromagnet means in synchronizm with movements of said shuttle under the action rf said first and second cams when said drive means respectively rotates said control member in said first and second directions, said control switch means comprising stationary first contact means and rotary second contact means receiving motion from said control member, said stationary first contact means comprising first and second fixed contacts and said rotary contact means being connected with one terminal of said electromagnet means and being intermittently engaged by said fixed contacts in response to rotation thereof, said selector means comprising means for connecting a selected fixed contact with the other terminal of said electromagnet means whenever the selected fixed contact is engaged by and disengaged from said rotary contact means.

Claim 19

A combination as defined in claim 15, wherein said rotary contact means comprises a plurality of discrete rotary cOntacts and wherein said first fixed contact is engaged by a larger number of discrete rotary contacts than said second fixed contact during each revolution of said rotary contact means.

Claim 20

A combination as defined in claim 16, wherein said first and second fixed contacts are respectively engaged by eighteen and six discrete rotary contacts per second.