Polaroid Corporation

June C Fichter

Kenneth A McAuley

Theodore J LaBelle

James J Alex

A sheet clamping system for rotatable drums especially suited for use in retaining and positioning successive receiver sheets for high speed printers. The clamping system enables unidirectional movement of a sheet during delivery of the sheet to the drum from a supply stack, during clamping of the leading edge of the sheet to the drum followed by clamping of the trailing edge of the same sheet to the drum and during subsequent release and delivery of the sheet to a receiving stack or tray. The system features a cam system for actuating respective leading and trailing edge clamps which is supported on the same shaft to which drum driving rotation is supplied by a drive motor. In one embodiment where the drive motor is reversible, a one-way clutch connection of the drum to the shaft enables drum rotation during one rotational direction of the shaft whereas clamping bar actuation is effected by rotation of the shaft in the opposite direction while holding the drum. In an alternative embodiment, the drum is fixed to the shaft which is driven in a working direction only by a first relatively high speed motor, the cam system is rotatable on the shaft, and a second relatively slow speed stepping motor drives the cam system and the drum during sheet loading and unloading operations.

Sheet clamping arrangement for rotatable drums

A counterbalancing and sheet clamp retention system for high speed sheet handling drums of the type in which leading and trailing edge clamping bars extend along the length of the drum periphery and are capable of movement between retracted and sheet clamping positions for automatic loading and unloading successive sheets to and from the drum. The clamping bars, supported at opposite ends for movement between their respective retracted and clamping positions, are engaged centrally along their length by a retaining device which moves to a clamping bar engaging position under centrifugal force as the rotational velocity of the drum reaches a predetermined value. The retaining device is a self-contained unit insertable through a radial opening in the drum and contains a pair of bell crank retainers each having a clamping bar engaging claw on one arm and a weight on the other arm so that centrifugal force operates to pivot the bell crank and bring the claws thereon into engagement with the closed sheet clamping bars. The drum is further counterbalanced by a fixed weight opposite from the movable bell crank weights. Further, the ends of the clamping bar are moved against the drum periphery to their sheet clamping positions by centrifugal force acting on counterbalancing weight carried by radially movable brackets from which the ends of the respective clamping bars are supported.

Sheet clamp counterbalancing system for high speed sheet handling drums

Photographic camera back or similar article

A self-developing camera back is provided with a film processing assembly that is removably received in a recess within a camera back housing and is releasably retained therein by a slidable retaining member that also functions as a film unit guide. The processing assembly includes a support frame, a pair of bearing block assemblies supporting a pair of pressure-applying rollers, a movable edge control bar and a spring assembly for retaining the bearing block assemblies and edge control bar in corresponding support frame receiving channels and for applying biasing forces to one of the rollers and the edge control bar.

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Canton, MA, United States of America

June C Fichter