Abstract A camera for roll film having perforations at predetermined metering intervals includes a transport mechanism for advancing the film along an exposure plane and a metering mechanism having an active condition for stopping film transport when the film is correctly positioned for exposure and an inactive condition. A film sensing pawl is mounted for movement between a retracted position resting on the film surface, an extended position transversing the film while in a film perforation and a metering position spaced from the extended position in the direction of film advancement. When moved to its metering position by advancing film, the sensing pawl actuates the metering mechanism to disable the transport mechanism. A resilient force is applied to the sensing pawl in a direction urging the pawl from its metering position toward its extended position. The force on the sensing pawl is sufficient to cause the film to move in a direction opposite to the direction of film advancement after the transport mechanism has been disabled to accurately back the film to a position for exposure. Once backed to its extended position, the sensing pawl engages a stop to relieve the spring force on the film.
In a camera adapted to receive roll film perforated at predetermined metering intervals and having (1) transport means for advancing received film in a first direction across the camera''s exposure plane, (2) a film sensing pawl movable by advancing film from a first position extending into a film perforation advanced into alignment therewith to a second position spaced from said first position along said exposure plane generally in said first direction, and (3) metering means associated with said transport means and said sensing pawl for disabling said transport means when said sensing pawl is moved to its second position, the improvement comprising spring means, urging said sensing pawl from its second position toward its first position, for moving received film in the direction opposite to said first direction after said transport means has been disabled.
Claim 2
Dependent Claim
135 words
In a camera adapted to receive roll film perforated at predetermined metering intervals and having (1) transport means for advancing received film in a first direction across the camera''s exposure plane, (2) a film sensing pawl movable by advancing film from a first position extending into a film perforation advanced into alignment therewith to a second position spaced from said first position along said exposure plane generally in said first direction, and (3) metering means associated with said transport means and said sensing pawl for disabling said transport means when said sensing pawl is moved to its second position, the improvement comprising spring means, urging said sensing pawl from its second position toward its first position, for moving received film in the direction opposite to said first direction after said transport means has been disabled.
Claim 3
Dependent Claim
44 words
The improvement as defined in claim 1 further comprising stop means in the path of said sensing pawl for limiting the amount of such travel of said sensing pawl in said opposite direction, whereby the film will be accurately registered in said exposure plane.
Claim 4
Dependent Claim
42 words
The improvement as defined in claim 1 further comprising means for opposing the force of said spring means after said sensing pawl has been returned to its first position, whereby said force is not transmitted by said sensing pawl to the film.
Claim 5
Dependent Claim
42 words
The improvement as defined in claim 3 wherein said foRce opposing means comprises stop means in the path of said sensing pawl for engagement by said sensing pawl to limit the amount of travel of said sensing pawl in said opposite direction.