Abstract: A transparency viewing system employs an illuminated viewer adapted to be used with an overlay device and/or film retaining clips. Brackets are provided to define longitudinal open channels at opposite edges of the illuminated viewing surface. The overlay device is of a size to span the viewing surface such that the marginal edges thereof, which have a configuration similar to that of the open channels, may be inserted into the open channels so that the overlay device is held against the viewing surface. Each retaining clip includes a mounting portion having a configuration similar to that of the channels and may be adjustably positioned along the channels so that its operating portion is biased against the viewing surface to hold transparencies placed between the clip and the viewing surface in position.

Abstract: A cabinet device is provided for use in combination with an abrasive blasting system. The inner chamber of the cabinet device is maintained at a pressure of less than ambient air pressure during an abrading operation by applying a source of vacuum to an exhaust outlet in the bottom of the cabinet below the article being abraded which is supported on a rack in the chamber. A blasting gun in the chamber is manipulated from outside the cabinet by an operator. An inlet for ambient air is located in the cabinet above the article on the rack and, during an abrading operation, establishes a continuous current of air downwardly toward the cabinet exhaust outlet to clear the space in the cabinet above the rack of view-obscuring debris and dust caused by the blasting operation. An improved sealing device between the cabinet cover and the peripheral sidewall of the cabinet housing is also provided.

Abstract: An abrasive surface treating device includes a gun connected to a pressurized air source, a housing containing a supply of abrasive material, an abrasive delivery line connected to the gun and having an aperture adjacent the housing outlet, a shroud to capture spent abrasive, and a vacuum source to draw spent abrasive and debris from the shroud back to the interior of the housing. The delivery of air at high velocity through the gun draws air through the abrasive delivery line via the aperture and thereby draws abrasive from the housing into the air stream flowing from the aperture to the gun so that the abrasive may be propelled against a work surface. The effective size of the aperture may be changed to alter the flow rate of various abrasive materials. In addition, the gun and abrasive delivery line may be connected to an adapter which, in turn, receives a shroud member having a configuration selected in accordance with the shape of the work surface.

Abstract: An overlay device, which is adapted for use with an illuminated transparency viewer, for holding slides and the like includes a series of spaced apart elongate members, frame members transverse to the elongate members to maintain the elongate members in fixed position, and resilient material carried by at least one of the elongate members such that a slide may be inserted between two successive elongate members by depressing said resilient material to insert one edge of the slide therein with the opposite edge being urged against the opposite elongate member to hold the slide in position. The elongate members have channels into which the slides may be inserted, the resilient material being disposed in at least one of the channels.

Abstract: An overlay tray for holding a plurality of photographic slides in side-by-side relationship is integrally formed from transparent plastic and defines a series of parallel, longitudinal channels. Each channel has a longitudinal groove adjacent one channel wall so that pressure applied to the edge of the slide above the groove pivots the opposite edge of the slide outward from the channel. The walls of the overlay tray are constructed so that the trays may be stacked one upon the other in interfitting relationship with the bottom of one tray retaining the slides in fixed position within the tray below. A flange extends from one end of the overlay tray so that an identifying label placed thereon can be read through a stack of such trays.

Abstract: An illuminated transparency viewing device is supported by a leg construction which may be adjusted to orient the viewer at different angles relative to a supporting surface. Two pairs of spaced apart legs are provided, each leg being pivotally mounted to the viewer housing for movement between retracted and extended positions so that either pair may be retracted or extended to tilt the viewer on edge. Each pair of legs may be of different length than that of the other pair. One leg of each pair is colinearly arranged with a corresponding leg of the other pair to define a pair of leg assemblies. Each leg assembly therefore has a pair of legs, each being mounted for pivotal movement between the side walls of a U-shaped bracket secured to the bottom of the viewer housing and may be extended from or retracted into the bracket.

Abstract: A picture screen comprising an upright standard, a leg unit supporting the standard, a roller adapted to receive a picture screen, a picture screen mounted on the roller and adapted to be unwound from a closed position to an open position, an elongated screen casing for receiving the roller and the screen coupled to the upright standard, and casing extensions integrally formed with the screen casing and each being provided with a speaker mounted therein. The speakers project the sound toward the viewer/listener to provide a lifelike effect with the picture projected on the screen.

Abstract: A pair of illuminated transparency viewers may be mounted on a supporting frame assembly so that one viewer generally provides a horizontally oriented viewing surface and the other viewer generally provides a vertically oriented viewing surface. The frame assembly includes a base portion adapted to receive the legs of one of the viewers and an upright portion adapted to receive the legs of the other viewer. The base portion and the upright portion each have a U-shaped cross section to define an open channel into which the respective legs of the viewers are inserted and secured by appropriate means. Two frame assemblies are utilized to mount the viewers which have two leg assemblies, each of which, in turn, has a leg pivotally mounted for movement between retracted and extended positions.

Abstract: A projection screen apparatus includes an elongate roller, a flexible screen which is wound on the roller when it is in a closed position and unwound from the roller when it is in an exposed position, an electric drive motor connected to the roller for rotating the roller to move the screen between exposed and closed positions, a first switch for actuating the drive motor to move the screen toward a closed position, and a second switch for stopping the drive motor and the roller when the screen is in a fully closed position. A free marginal end portion of the screen engages a lever which moves the second switch to an inoperative position to interrupt the electric circuit leading to the drive motor.

Abstract: A projection screen apparatus includes a modular screen unit and a separate modular drive motor unit generally forming an extension of the screen unit. The screen unit has an elongate roller and a flexible screen which is wound on the roller when it is in a closed position and unwound from the roller when it is in an exposed position. The drive unit is detachably secured adjacent the screen unit and has an electric motor releasably coupled to the roller to rotate the roller to move the screen between exposed and closed positions.

Abstract: A brake mechanism for an electric motor used to drive a projection screen apparatus. The brake mechanism includes a first brake surface fixed to an exterior brake support about an end of the motor shaft projecting from the housing, a second brake surface adjustable on the shaft end and confronting the first brake surface, and a spring for normally urging the brake surfaces into engagement to prevent rotation of the shaft, and brake surfaces being urged apart and the action of the spring counteracted when the motor is operated as the rotor of the motor, which is carried by the shaft, aligns itself with the magnetic field generated by the stator of the motor.

Abstract: A projection screen apparatus includes an elongate roller, a flexible screen which is wound on the roller when it is in a closed position and unwound from the roller when it is in an exposed position, an electric drive motor connected to the roller for rotating the roller to move the screen between exposed and closed positions, a first switch for actuating the drive motor to move the screen toward an exposed position, and a second switch for stopping the drive motor and the roller when the screen is in a fully exposed position. A lever urged against the screen wound on the roller moves the second switch to an inoperative position when a predetermined amount of screen is unwound from the roller to interrupt the electric circuit leading to the drive motor.