The BBI Combinatory Dictionary of English

A slide projector for slides mounted on a slide holder having a series of clips around an endless flexible belt which is inserted in the projector through an access opening in the top wall, fitted loosely around parallel rotary supporting elements permanently mounted in the recess to project toward the access opening, located at the proper level in the projector by positioning surfaces in the projector, and then tensioned by moving one of the supporting elements away from the other. The movable supporting element is positioned in one of a plurality of different zones, for slide holders of different capacities, and is spring-loaded in each zone to apply the proper tensioning force. Feeding of the slides is accomplished by a reciprocating motor and a driver having a reversible ratchet coupling with one of the rotary elements which has teeth for engaging the overhanging end portions of alternate clips around the belt, and the driver also serves as the actuator for a positioning fork which locks the slide to be projected against one of the rotary elements. In a modified form, the driver also operates a hold-out apparatus engageable with the slides on opposite side of the one being projected, and an oscillating shutter for blocking the light beam during slide changing.