Vertically rotatable display prisms - have spindles with triple pulleys driven by adjustable belts, and vertically mounted drive motor parallel with prisms

摘要

Display prisms (5) of triangular section are rotatable about their vertical axes. The spindles (7) have triple pulleys (13) driven on both sides by toothed belts (14,15). Belts are arranged symmetrically, with two outers (15) and one inner (14) alternately. The drive motor is mounted vertically, parallel to and in line with the prisms. Bearings above and below the pulleys are mounted on plates (10) over apertures in the box-section top beam (1). Spacing and belt tension are adjusted by means of slots (11) and locking bolts (12). Short lower axles (3) rest in nylon bushes in the bottom frame (2).