Film advance mechanism
AssigneeErnst Leitz Wetzlar GmbH
InventorRolf Crema
Life of this patent
Estimating the term…
Abstract
In a film advance mechanism for perforated film, locking elements are provided to guarantee the image position for each exposure. They block the film transport sprocket against further movement after completion of each full film advance carried out via the camera winding mechanism. In addition, the mechanism releases the film transport sprocket from the blocked condition on completion of the camera shutter cycle.
Claims8
A film advance mechanism for producing a uniform image position of perforated film in a photographic camera for each successive exposure, comprising:
- a film transport sprocket engaging with the film perforations;
- a profiled locking mechanism responsive to a film winding mechanism on the camera for locking the film transport sprocket toward the end of each film advance, the profiled locking mechanism comprising a detent wheel mounted on the film transport sprocket, a detent lug and means for engaging the detent lug in the detent wheel at the end of each film advance;
- and
- a roller operatively connected with the camera shutter and the detent lug such that the roller lifts the detent lug out of the detent wheel after completion of a camera shutter cycle.
A film advance mechanism for producing a uniform image position of perforated film in a photographic camera for each successive exposure, comprising:
- a film transport sprocket engaging with the film perforations;
- a film winding mechanism;
- a roller operatively connected with the camera shutter;
- a detent wheel mounted on the film transport sprocket;
- a lever rotatable about a pivot point, the lever including a detent lug for engaging the detent wheel, a catch lug and an arm which is contactable by the roller to initiate rotation of the lever about the pivot point upon release of the camera shutter;
- spring means for rotatably biasing the lever into a position in which the detent lug rests in the detent wheel;
- a catch lever rotatable about a pivot point and having a catch means for engaging the catch lug, whereby the catch lug is engaged and held by the catch means upon rotation of the lever by the roller;
- and
- a counter revolution catch associated with the film winding mechanism and operable to move the catch lever at the end of each film advance away from the catch lug so as to release the catch lug, whereby the detent lug returns into engagement with the detent wheel.
A film advance mechanism for producing a uniform image position of perforated film in a photographic camera for each successive exposure, comprising:
- a film transport sprocket engaging with the film perforations;
- means for locking the film transport sprocket against further movement after completion of each full film advance;
- a film winding mechanism;
- and
- means for holding the locking means out of engagement with the film transport sprocket, the holding means operatively connected to the film winding mechanism and to the camera shutter, the holding means being adapted to move the locking means out of a locked position with the film transport sprocket at the end of each camera cycle and to return the locking means to a locked position with the film transport sprocket after each full film advance whereby the film transport sprocket is placed in an unlocked condition for each film advance following each camera shutter cycle.
Dependencies are inferred from the claim text.