Abstract: 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.

Abstract: 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.

Abstract: A fluid drop dispensing device, particularly suited for ink jet printer heads, in which a circular electroactuator is supported in concentric relationship with inner and outer ring members defining an annular chamber which is reduced in volume upon excitation of the electroactuator. The chamber is defined as a peripheral groove in one or the other of the inner and outer rings and is rendered fluid tight exclusively by peripheral ring surface contact maintained by hoop stress in the two rings as a result of press fitting the inner ring into the outer ring. Both rings may be of plastic material selected for appropriate characteristics or in the alternative, the outer ring may be of plastic while the inner ring is metallic and fabricated of stainless steel or nickel, for example.

Abstract: An accessory for use in an instant camera designed for standard film packs and by which the same camera can be used to expose and process self-processing film sheet assemblies of reduced image format size prepackaged in corresponding sized film packs. The accessory is in the nature of a U-shaped housing having exterior planar dimensions to complement the interior planar dimensions of a well in the camera for receiving a standard film pack. The U-shaped configuration of the housing defines a recess to receive and position the modified film pack of reduced size. The accessory carries movement transmitting relays by which actuation of a camera mounted switch is energized by insertion of the modified film pack and by which movement of a camera carried pick is transmitted to an accessory pick for initial ejecting movement of an exposed film sheet from the modified pack.