US 4,788,566 AGranted

Photographic cassette for manipulation and exposure of a light-sensitive sheet

AssigneeSinar AG Schaffhausen

InventorCarl Koch

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Abstract

A cassette having a housing with an opening for the light to penetrate when exposing a film sheet, loaded into the cassette, and also for the entry and exit of the film sheet when loading and unloading the cassette. For gripping the edges of the film sheet, inserted into the cassette, there are movable retaining members, which can be moved into ineffective positions outside the contours of the opening of the housing, to facilitate the entry and exit of the film sheet in a direction perpendicular to its plane. When the retaining members are moved into their effective positions, a pressure plate under the influence of a spring forces the film sheet, to be loaded into the cassette, against the retaining members, whereby the film sheet is held planar. Externally accessible actuators interact in the manner of rams with both the pressure plate and the retaining members such that at times when moving the actuators from an inactive into an active position, the pressure plate is forced away from the retaining members and the retaining members are moved into their ineffective positions, and vice versa.

Photographic cassette for use and exposure of a light-sensitive sheet, for application in a large format camera, comprising a flat rectangular housing for the reception of the light-sensitive sheet;

the housing having an opening;
a flat light-proof slider, movable within the housing, for opening or light-seal closing the opening;
the light-proof slider having an actuating end and a path of movement parallel to its flat faces, said opening conforming in shape and size to the light-sensitive surface of the sheet and permitting not only the light to enter when exposing the sheet but also the sheet to pass there-through when loading and unloading the cassette in a direction perpendicular to the sheet;
a supporting surface in the housing for bracing the back side of the sheet opposite the light-sensitive front side thereof;
and a plurality of retaining members in the housing for gripping the edges of the light-sensitive front side of the sheet;
at least some of said retaining members being movable into operative and inoperative positions and, for loading and unloading the cassette, are moved out of their operative positions into their inoperative positions outside a path of motion, required for the light-sensitive sheet as the cassette is loaded or unloaded;
at least one externally accessible actuator for interacting with the retaining members and being movable between an inactive position in which the retaining members are moved into their operative positions, and an active position in which the retaining members are moved into their inoperative positions, wherein a pressure plate contains the supporting surface, the plate being under the spring bias of at least one pressure spring which urges the pressure plate in a direction against the opening of the housing for clamping the light-sensitive sheet between the supporting surface of the pressure plate and the retaining members moved into their operative positions;
and wherein the actuator for moving the retaining members is connected to a controller interacting with the pressure plate such that each movement of the actuator into its active position also results in the pressure plate being forced back against the influence of the pressure spring in order to provide a free space between the supporting surface of the pressure plate and the retaining members.

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Abstract

Claims25