Means for alternately indexing two slide trays which differ in respective distances between adjacent slide-receiving spaces

Claim 1

In combination: a. a slide projector having a horizontally disposed, planar slide tray receiving surface, which is annular in shape and adapted to receive at least two alternative circular slide trays having unequal slide capacity, but substantially equal exterior dimensions; b. said projector supporting an indexing mechanism adjacent said surface, which mechanism includes at least one indexing gear having a plurality of teeth and means for intermittently rotating the same through a predetermined arcuate extent to esTablish an indexing cycle, said gear being mounted for such movement and about an axis perpendicular to said surface; c. A first circular slide tray having an annular supporting rim and adapted to be slidably supported in a horizontal position on said projector with such rim in adjacent concentric relationship with said surface; d. said first tray having a plurality of equally spaced, radially extending partitions defining a corresponding number of spaces each adapted to receive a slide of predetermined thickness; e. said first tray having a continuous annular series of first spaced indexing projections radially disposed interiorly of said rim, said projections comprising a pair of faces converging toward the center of the tray and defining therebetween at the outermost ends of the inclined faces corner formations arranged and shaped to be successively engaged by said indexing gear at the distal end of the teeth of said gear such that rotation of the latter through said predetermined arcuate extent advances said first tray about its central axis in the same rotational direction as said gear and through an arc represented by the center-to-center spacing of adjacent slide-receiving spaces of said first tray; f. a second circular slide tray having substantially the same exterior dimensions as said first tray and having an annular rim of substantially the same diameter as the rim of said first tray, which second tray is adapted to be slidably supported in a horizontal position on said projector, alternately with said first tray, with the rim of the second tray in adjacent concentric relationship with said surface; g. said second tray having a plurality of equally spaced, radially extending partitions defining a corresponding number of spaces each adapted to receive a slide of a predetermined thickness which is less than the thickness of said firstmentioned slide, the number of spaces in said second tray being greater than the number of spaces in said first tray; and h. said second tray having a continuous annular series of second spaced indexing projections radially disposed interiorly of said rim, said projections comprising a pair of radial side faces extending inwardly from the outermost ends of the projections to a midpoint thereof and a second pair of faces extending from the midpoints and converging toward the center of the tray, the midpoint junctures of the sides and inclined faces defining corner formations arranged and shaped to be successively engaged by said indexing gear at a predetermined point on the teeth of said gear which is radially inward of their distal end such that rotation of said gear through said predetermined arcuate extent advances said second tray about its central axis in the same rotational direction as said gear and through an arc represented by the center-to-center spacing of adjacent slide receiving spaces of said second tray.