Slide projector for use with straight and circular slide trays

Claim 1

In an arrangement of the character indicated, a combination comprising a straight slide tray having transversely extending compartments for slides and an underside provided with a pair of straight parallel channels communicating with said compartments; a circular slide tray having radially extending compartments for slides and an underside provided with a pair of concentric annular channels communicating with said last mentioned compartments; and a slide projector including a housing having first and second passages respectively arranged to receive said straight and circular trays, said passages having a common portion so that said first passage is free to receive said straight tray only when said circular tray is removed from said second passage and vice versa, slide changer means installed in said housing for movement between first and second positions to thereby transport slides between those compartments of one of said trays which are located in said common portion of said passages and a viewing position, and lifting means comprising a pair of cams provided in said common portion of said passages below said slide changer means and having faces arranged to raise from a lower level to a higher level successive slides in that one of said trays which is inserted into the respective passage, the positions of said cams being such that each thereof enters a different one of said straight channels from below said channels upon insertion of said straigHt tray into said first passage and a different one of said annular channels on insertion of said circular tray into said second passage, portions of said annular channels and said straight channels being disposed in said common portion of said passages when said straight and circular trays are alternatively used, said circular tray being indexible about a substantially vertical axis and said straight tray being indexible lengthwise upon insertion into the respective passage of said housing.