Slide projector with stationary slide magazines and automatic slide changer

Claim 1

In a slide projector having an optical pathway comprising first and second slide magazines for housing individual slides mounted in slide frames, said first and second magazines being located on opposite sides of the optical pathway of the slide projector, each of said first and second magazines including a feed and discharge opening for receiving and discharging said slide frames, said opening being located in the focal plane of the slide projector, and a reversible slide transport device for transporting the slide frames between said first and second magazines through said respective feed and discharge openings, via the projection position of said projector for projecting said individual slides, the improvement wherein said slide transport device comprises first and second toothed belts located in said focal plane, first and second gear wheels attached on first and second axles, respectively, said axles being located, respectively, outside said first and second magazines, in a direction perpendicular to said optical pathway, said toothed belts being stretched over said gear wheels, at least one of said first and second axles being driven, and, a plurality of external dog members carried on the periphery of each of said first and second belts, said dog members being spaced one from the other a distance corresponding to the width of one of said slide frames, said toothed belts each having a length which corresponds to an integer number of slide frame divisions, whereby, when said toothed belts are driven in one direction by said axles and gear wheels, said slide frames will be individually transported in said plane by and in engagement between consecutive of said dog members from said first slide magazine to said second slide magazines, via said projection position, and when said toothed belts are driven in the opposite direction by said axles and gear wheels said slide frames will be individually transported in said focal plane by and in engagement between consecutive of said dog members from said second slide magazine to said first slide magazine, via said projection position.