Projector slide suitable for audio visual educational application - consists of two hinged plastic frames meshing like book, locked by U-shaped pins

摘要

The individual slides can be hooked together to form a chain and used in an automatic audio visual projection system for educational purposes etc. Each slide is made up from two identical plastic frames with tubular hinge extensions along two opposite edges and a square window in the centre for the positive. The inner faces are made up on three sides of the window. This forms a U with the cross member along opposite edges of each window. The thickness of the cross members is twice that of the parallel members. When the two frames are fitted together like a closed book, the two cross members will mesh in the open sections above each window. The tubular extensions on the two edges will have common axes and the slide will be locked with U-shaped pins.