Film metering mechanism for cameras

Claim 2

In a camera adapted to receive perforated roll film and having (1) transport means for advancing received film along an exposure plane, (2) a sensing pawl movable from a retracted position on one side of said exposure plane to an extended position through a film perforation for detecting the arrival of the film perforation at a predeterMined position and (3) metering means associated with said transport means and said sensing pawl for disabling said transport means upon arrival of a film perforation at said predetermined position; the improvement comprising: resilient means for urging said sensing pawl toward its retracted position; and means for holding said sensing pawl in its extended position against the urging of said resilient means only until a perforation has arrived at said predetermined position and for thereupon enabling said resilient means to move said sensing pawl to its retracted position.

Claim 3

The improvement as defined in claim 1 wherein: said metering means includes (1) a lever movable between an active position disabling said transport means and an inactive position, (2) spring means urging said lever toward its active position and (3) means on said lever cooperative with said sensing pawl for preventing movement of said lever to its active position until the perforation has arrived at said predetermined position; and said means for holding said sensing pawl in its extended position includes a surface on said lever engageable by said sensing pawl only until a perforation has reached said predetermined position.

Claim 4

In a camera adapted to receive roll film and having (1) transport means for advancing received film along an exposure plane, (2) a sensing pawl movable from one side of said exposure plane to an extended position traversing said exposure plane through a film perforation and to a metering position from its extended position by advancing film, said metering position being spaced from said extended position in the direction of film travel and (3) metering means associated with said transport means and said sensing pawl for disabling said transport means when said sensing pawl has moved to its metering position; the improvement comprising: a spring urging said sensing pawl out of the film perforation toward said one side of said exposure plane; and means for holding said sensing pawl in a perforation when in its extended position and until said sensing pawl has been moved to its metering position.

Claim 5

In a camera adapted to receive roll film and having (1) transport means for advancing received film along an exposure plane, (2) a sensing pawl movable from one side of said exposure plane to an extended position traversing said exposure plane through a film perforation and to a metering position from its extended position by advancing film, said metering position being spaced from said extended position in the direction of film travel and (3) metering means associated with said transport means and said sensing pawl for disabling said transport means when said sensing pawl has moved to its metering position; the improvement comprising: a spring urging said sensing pawl out of the film perforation toward said one side of said exposure plane; and means for holding said sensing pawl in a perforation when in its extended position and until said sensing pawl has been moved to its metering position.

Claim 6

The improvement as defined in claim 3 wherein: said metering means includes (1) a lever movable between an active position and an inactive position, (2) means on said lever for disabling said transport means when said lever is in its active position and (3) resilient means for urging said lever toward its active position; and said holding means includes abutment surfaces on said lever and said sensing pawl, said abutment surfaces being arranged to block movement of said sensing pawl from a film perforation until said sensing pawl has moved to its metering position.

Claim 7

The improvement as defined in claim 4 wherein said abutment surfaces are further arranged to block movement of said lever to its active position until said sensing pawl has moved to its metering position.

Claim 8

In a camera having (1) means for receiving roll film perforated at predetermined metering intervals, (2) transport means for advancing received film along an exposure plane, (3) a film sensing pawl having a generally rectilinear movement sequentially between a first position contacting the surface of received film at said exposure plane, an extended position traversing said exposure plane when intercepting a film perforation, a metering position to which said sensing pawl is moved from its extended position by the trailing edge of a film perforation as film is advanced and a fourth position removed from the perforation, (4) a metering lever movable between an active position disabling said transport means and an inactive position, (5) spring means for urging said sensing pawl out of a perforation and toward its first position, (6) resilient means for urging said metering lever toward its active position; the improvement comprising means associated with said sensing pawl and said metering lever: for holding said metering lever in its inactive position when said sensing pawl is in its first position and until said sensing pawl reaches its metering position; and for holding said sensing pawl in a perforation until it reaches its metering position and for thereupon permitting movement of said sensing pawl to its fourth position by said spring means.

Claim 9

In a camera having (1) means for receiving roll film perforated at predetermined metering intervals, (2) transport means for advancing received film along an exposure plane, (3) a film sensing pawl having a generally rectilinear movement sequentially between a first position contacting the surface of received film at said exposure plane, an extended position traversing said exposure plane when intercepting a film perforation, a metering position to which said sensing pawl is moved from its extended position by the trailing edge of a film perforation as film is advanced and a fourth position removed from the perforation, (4) a metering lever movable between an active position disabling said transport means and an inactive position, (5) spring means for urging said sensing pawl out of a perforation and toward its first position, (6) resilient means for urging said metering lever toward its active position; the improvement comprising means associated with said sensing pawl and said metering lever: for holding said metering lever in its inactive position when said sensing pawl is in its first position and until said sensing pawl reaches its metering position; and for holding said sensing pawl in a perforation until it reaches its metering position and for thereupon permitting movement of said sensing pawl to its fourth position by said spring means.