Film-transport control for sound-film camera

Abstract

A cine camera for taking talking pictures, in which a film is moved intermittently past an image gate by a reciprocating traction claw and continuously past a recording head by a rotating capstan coacting with a pinch roller, includes a latch by which the pinch roller can be held spaced from the capstan in an inactive position. The latching of the pinch roller in this inactive position, against the force of a biasing spring providing the necessary contact pressure during filming, is accomplished upon deactivation of the film drive by the residual kinetic energy of an inertial mass such as a flywheel which is coupled with either the capstan drive or the claw drive. The latch is released upon actuation of a trigger, either directly or through the intermediary of the claw drive. The biasing spring may be part of a toggle mechanism tripped by a presetting member, such as a sensor detecting the presence of a sound-film cassette in the camera.

We claim: 
     
       1. In a cine camera, in combination: a casing adapted to accommodate a perforated motion-picture film having a sound track, said casing being provided with an exposure gate and sound-recording means;   electrically powered drive means in said casing for transporting said film past said exposure gate and said sound-recording means, said drive means including a reciprocable traction claw engageable with the film perforations in the vicinity of said exposure gate and further including a continuously rotatable capstan and a pinch roller adapted to clamp said film therebetween in the vicinity of said sound-recording means;   relatively displaceable support means for said pinch roller and said capstan, said support means including a movable member determining the relative spacing of said pinch roller and said capstan;   biasing means engaging said movable member for urging same from an inactive position into an active position in which the film is clamped between said capstan and said pinch roller;   latch means engageable with said movable member for releasably retaining same in said inactive position;   actuating means for energizing said drive means, said latch means being operatively linked with said actuating means for releasing said movable member at the start of a picture-taking operation; and   restoring means coupled with said drive means for re-engaging said movable member with said latch means by residual kinetic energy upon a de-energization of said drive means by said actuating means.   
     
     
       2. The combination defined in claim 1 wherein said restoring means includes a rotatable flywheel mass. 
     
     
       3. The combination defined in claim 2 wherein said flywheel mass is rigid and coaxial with said capstan. 
     
     
       4. The combination defined in claim 2 wherein said drive means includes a continuously rotatable shaft coupled with said traction claw, said flywheel mass including a shutter disk mounted on said shaft in line with said exposure gate. 
     
     
       5. The combination defined in claim 1 wherein said latch means is operatively linked with said actuating means through the intermediary of said traction claw. 
     
     
       6. The combination defined in claim 5, further comprising a loop detector in said casing displaceable from a normal position into an off-normal position by a looped stretch of film engaged by said traction claw, said latch means being coupled with said loop detector. 
     
     
       7. The combination defined in claim 5, further comprising film-winding means in said casing including a reciprocable pawl mechanically coupled with said traction claw, said latch means being articulated to said pawl. 
     
     
       8. The combination defined in claim 1, further comprising presetting means operable independently of said actuating means to displace said movable member into said inactive position from an insertion position in which the relative spacing of said pinch roller and said capstan is greater than in said inactive position, said presetting means including a toggle mechanism, said biasing means being a spring forming part of said toggle mechanism and reversing the direction of its biasing force in said insertion position. 
     
     
       9. The combination defined in claim 8 wherein said presetting means includes a feeler extending into a cassette-receiving compartment of said casing for ascertaining the presence of a sound-film cassette therein. 
     
     
       10. The combination defined in claim 1 wherein said drive means includes a continuously rotatable shaft coupled with said traction claw, said restoring means comprising an element positively connected with said shaft for coacting with said movable member and concurrently arresting said traction claw in a predetermined position of the latter. 
     
     
       11. The combination defined in claim 10 wherein said latch means is operatively linked with said actuating means through a further element of said drive means positively coupled with said traction claw for releasing said movable member in another predetermined position of said traction claw. 
     
     
       12. The combination defined in claim 11 wherein said further element is a rotatable cam provided with a cam follower linked with said latch means. 
     
     
       13. The combination defined in claim 12 wherein said latch means and said movable member are provided with coacting camming formations for disengaging said cam follower from said cam in a released position of said movable member. 
     
     
       14. The combination defined in claim 1 wherein said restoring means includes a cam coupled with said drive means for continuous rotation thereby, said cam being provided with a cam follower linked with said movable member, and catch means linked with said actuating means for holding said cam follower out of contact with said cam during energization of said drive means. .Iadd. 15. In a cine camera, in combination: a casing adapted to accommodate a perforated motion-picture film having a sound track, said casing being provided with an exposure gate and sound-recording means;   electrically powered drive means in said casing for transporting said film past said exposure gate and said sound-recording means, said drive means including a reciprocable traction claw engageable with the film perforations in the vicinity of said exposure gate and further including a continuously rotatable capstan and a pinch roller adapted to clamp said film therebetween in the vicinity of said sound-recording means;   relatively displaceable support means for said pinch roller and said capstan, said support means including a movable first member determining the relative spacing of said pinch roller and said capstan;   a second member movable relatively to said first member;   first biasing means coupled with said movable members and effective in a predetermined position of said second member for urging said first member from an inactive position into an active position in which the film is clamped between said capstan and said pinch roller;   latch means engageable with said first member for releasably retaining same in said inactive position;   actuating means for energizing said drive means, said latch means being operatively linked with said drive means for releasing said first member at the start of a picture-taking operation;   restoring means controlled by said actuating means for displacing said second member from said predetermined position to an alternate position upon de-energization of said drive means to facilitate a return of said first member to said inactive position;   second biasing means connected with said first member for re-engaging same with said latch means upon displacement of said second member to said alternate position; and   cam means mechanically coupled with and receiving power from said drive means for returning said second member to said predetermined position after the re-engagement of said first member with said latch means and before the start of a new picture-taking operation. .Iaddend..Iadd. 16. The combination defined in claim 15 wherein said cam means is provided with a shaft rotatively entrained by said capstan via a transmission including a flywheel. .Iaddend..Iadd. 17. The combination defined in claim 15 wherein said members are levers, said first biasing means being a spring resiliently interlinking said levers. .Iaddend..Iadd. 18. In a cine camera, in combination:   a casing adapted to accommodate a perforated motion-picture film having a sound track, said casing being provided with an exposure gate and sound-recording means;   electrically powered drive means in said casing for transporting said film past said exposure gate and said sound-recording means, said drive means including a reciprocable traction claw engageable with the film perforations in the vicinity of said exposure gate and further including a continuously rotatable capstan and a pinch roller adapted to clamp said film therebetween in the vicinity of said sound-recording means;   relatively displaceable support means for said pinch roller and said capstan, said support means including a movable first member determining the relative spacing of said pinch roller and said capstan;   a second member movable relatively to said first member;   biasing means coupled with said movable members and effective in a predetermined position of said second member for urging said first member from an inactive position into an active position in which the film is clamped between said capstan and said pinch roller;   first latch means engageable with said first member for releasably retaining same in said inactive position;   second latch means engageable with said second member for releasably retaining same in said predetermined position;   actuating means for energizing said drive means, said first and second latch means being operatively linked with said actuating means for releasing said first member from said inactive position while holding said second member in said predetermined position at the start of a picture-taking operation, thereby allowing said biasing means to move said first member into said active position, and for deactivating said second latch means upon a de-energization of said drive means to release said second member into an alternate position with resulting return of said first member to said inactive position for re-engagement with said first latch means; and   restoring means coupled with and receiving power from said drive means for tensioning said biasing means by re-engaging said second member with said second latch means after the re-engagement of said first member with said first latch means and before the start of a new picture-taking operation.   
     
     
        .Iaddend. .Iadd. 19.  The combination defined in claim 18 wherein said first member is a lever carrying said pinch roller. .Iaddend..Iadd. 20. In a cine camera, in combination: a casing adapted to accommodate a perforated motion-picture film having a sound track, said casing being provided with an exposure gate and sound-recording means;   electrically powered drive means in said casing for transporting said film past said exposure gate and said sound-recording means, said drive means including a reciprocable traction claw engageable with the film perforations in the vicinity of said exposure gate and further including a continuously rotatable capstan and a pinch roller adapted to clamp said film therebetween in the vicinity of said sound-recording means;   relatively displaceable support means for said pinch roller and said capstan, said support means including a movable first member determining the relative spacing of said pinch roller and said capstan;   a second member movable relatively to said first member;   first biasing means coupled with said movable members and effective in a predetermined position of said second member for urging said first member from an inactive position into an active position in which the film is clamped between said capstan and said pinch roller;   latch means engageable with said first member for releasably retaining same in said inactive position;   actuating means for energizing said drive means, said latch means being operatively linked with said drive means for releasing said first member at the start of a picture-taking operation:   restoring means controlled by said actuating means for displacing said second member from said predetermined position to an alternate position upon de-energization of said drive means to facilitate a return of said first member to said inactive position;   second biasing means connected with said first member for re-engaging same with said latch means upon displacement of said second member to said alternate position; and   tensioning means coupled with and receiving power from said drive means for returning said second member to said predetermined position after the re-engagement of said first member with said latch means and before the start of a new picture-taking operation. .Iaddend.