B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
B65G21/00—Supporting or protective framework or housings for endless load-carriers or traction elements of belt or chain conveyors
B65G21/20—Means incorporated in, or attached to, framework or housings for guiding load-carriers, traction elements or loads supported on moving surfaces
B65G21/2027—Suction retaining means
B65G21/2036—Suction retaining means for retaining the load on the load-carrying surface