Abstract: A continuous conveyor for elevating articles such as trayed mail has a support frame on which are mounted sprockets which drive two parallel drive chains in vertical planes. A bar is connected between the chains and a carriage is rotatably connected to the bar. The carriage has a plurality of tines which form an elevatable platform. The carriage has a center guide roller which is guided along a closed looped path by vertical guide tracks and two side rollers guided by a separate set of tracks. Spring-loaded members maintain engagement of the side rollers with the track at the lower portion of carriage travel. The apparatus is substantially open at the front and the sides to permit infeed and outfeed from either the front or the sides. The front-loading conveyors have a plurality of sprocket-driven belts and the side loading conveyors have a plurality of driven rollers which interdigitate with the tines of the carriage to permit elevation of articles in a continuous stream.

Abstract: A recirculating ball slide for supporting heavy loads. The slide includes an oval ball race having a special concave ball track. The balls are retained in the race by means of a housing having a cut-away lower portion to expose the balls for mating engagement with a slide rail which also has a concave ball track.