A set of components for producing load-bearing scaffolds comprising profile bars and connecting bars each having an approximately .SIGMA.-shaped cross-section with a flat center web section. The connecting bars fit slidably in the profile bars to which they are attached by connecting means through perforations in each of the center web sections. The profile bars also have an inwardly angled free arm extending parallel to the center web section and having perforations to provide for connection of further components to the profile bars. Further components adapted for use with the above profile bars comprise fixing angles, packing pieces, cross-member brackets, reducing elements, bearing hole plates, angle elements and belt guide plates.

A roller assembly having longitudinal ribs which snap fit into shelf members of a support frame. In one embodiment the shelf members have upright T-shaped end members with lateral extending feet that engage the ribs. In another embodiment the shelf members have longitudinal feet that engage the ribs. Preferably, the edge forming the underside of the roller assembly are supported by base portions of the shelf member.

A conveyor apparatus comprises a plurality of conveyor rail segments joined longitudinally, each of said plurality of conveyor rail segments comprising: a support rail having an upper wheel-seating portion and a lower base portion, the lower base portion having a frustopyramidal cross-sectional shape, a substantially horizontal base panel, and a pair of inwardly angled side panels extending upwardly from opposing edges of the base panel and terminating at the upper wheel-seating portion; and a plurality of wheels translationally secured to the upper wheel-seating portion of the support rail and capable of rotating with respect to the support rail; whereby goods can be transported over the conveyor rail segment.

A mounting system for conveyor idlers incorporates an assembly nut having a plurality of different pairs of parallel faces spaced around the periphery of the nut, such faces being spaced apart by different distances to allow use of the mounting system with a plurality of different styles of mounting brackets.

A wheeled conveyor rail segment has a frustopyramidal cross-sectional shaped support rail, which can be made from roll-formed galvanized steel. A plurality of wheels are joined to the galvanized steel support rail and can rotate with respect thereto, enabling goods to be transported by rolling over the conveyor rail segment. The wheel axles can be held in place by axle bearing units that slide into longitudinal grooves in the support rail. All materials can be made electrically conductive, allowing the conveyor rail segment to be used in applications where control of electrostatic discharge is desired, such as handling semiconductor materials and electronic equipment.