Abstract: A projector stacking stand for supporting at least one image projector comprises a frame and at least one mounting platform connected to the frame with ends supporting an image projector. Each mounting platform is connected to the frame for enabling adjustment of the pitch, roll and yaw thereof relative to the frame by means of a gimbal having three discrete pivot axes corresponding to pitch, roll and yaw axes. The gimbal is moved about the pitch and roll axes by two shafts, each mounted on the gimbal for independent rotation with the axis thereof disposed parallel to the pitch axis and a cable for each shaft having at least one turn therearound. Each cable is connected to the frame under tension with a portion above and below the turn around the shaft and each shaft is rotatable to effect vertical movement thereof along its cable, whereby pitch adjustment is obtained by rotating the two shafts simultaneously in the same direction and roll adjustment is obtained by rotating the shafts individually.

Abstract: A lamp changer for use with a slide projector having a projection lens and a removably modular projection lamp unit insertable through an access door opening. The lamp changer has a housing releasably connectable to the projector at the access opening and a lamp holder for holding at least two projection lamps. The lamp holder is mounted in the housing for pivotable movement about a first axis to successively position each lamp in the lamp holder in direct alignment with the projection lens. Movement of the lamp holder is effected when desired and the new lamp is moved into alignment with the lens and is energized.

Abstract: A cartridge having a film handling portion and an audio tape cassette storing portion for use with an audio-visual system. The film storing portion includes a supply and take-up reel which are coupled by an intermediate gear so that the rotation of one reel is coupled to the other and means for transporting the film spooled about the reels past an aperture plate in either a continuous or intermittent motion mode. Provision is made in the cartridge for allowing the projection of light through the image portion of the film positioned at the aperture in the aperture plate and through an auxiliary frame in the film positioned at an auxilliary aperture to identify the number of the image portion being projected. A standard audio tape cassette containing the audio portion of the audio-visual presentation associated with the film may be stored in the tape cassette storing portion facing towards the opposite side of the cartridge from the aperture plate.