A transportation system comprises a continuous stationary track having a pair of opposed rigid bearing surfaces, and a plurality of discrete cantilevered load-carrying vehicle units movable beside said track. Each vehicle is coupled to the track by a bogie having a linear arrangement of bogie wheels running between the bearing surfaces. The bogie wheels are mounted on mutually articulated frames and have a diameter slightly less than the separation of the opposed bearing surfaces to allow limited pivoting movement of the frames within the track. The adjacent articulated frames are forcibly urged to pivot in opposite directions within the track between the bearing surfaces such that bogie wheels carried thereby forcibly and alternately engage the respective opposed bearing surfaces at at least three points to ensure a pro-loaded positive coupling between the bogie and the track.

A traveling mechanism for a lifting device, especially for a lifting device having a laterally cantilevering boom, is movable on rails with at least two running wheels. A connection element for attaching a load to said traveling mechanism is supported in the rail by the running wheels which are arranged on both sides of the connection element. The connection element has, at the region projecting down out of the rail, at least one running roller which is freely rotatable about a horizontal axis and rolls on a horizontal outer running surface of the rail. To effectively divert horizontal forces and uniformly distribute the vertical forces to the running wheels, running wheel axles are rigidly connected with a running wheel carrier, and the running wheel carrier and connection element are swivelably connected by a universal type joint. In addition, at least one support roller is rotatably mounted at the connection element in the interior of the rail. The support roller freely rotates about a vertical axis and rolls along at least one of the side surfaces to transmit horizontal forces to the rail.

A trap assembly is provided to collect materials dispelled from a ski lift cable suspension assembly. A ski lift post rotatably supports a plurality of wheels through which a longitudinally moveable cable is guided. A collection trough is disposed beneath the wheels and the cable to trap materials dispelled about the wheels.

A power-and-free trolley conveyor comprising a power line rail, a free line rail disposed immediately below the power line rail, another free line rail provided at one side of the free line rail in parallel thereto, and carriers suspended from the free line rails and each thereby supported at its opposite sides.

A door track adapted for carrying a trolley supporting a door for rolling movement. The door track includes one or more single-piece track members having a first substantially planar surface and a pair of substantially identical spaced apart portions extending from the first substantially planar surface and forming a channel with the first planar surface. The spaced apart portions each have a substantially planar portion adjacent the first substantially planar surface to provide a plurality of flat mounting surfaces. The spaced apart portions further include inwardly curved portions extending from the substantially planar portions which are adapted to support a trolley for rolling movement therealong. The inwardly curved portions are spaced apart to freely receive a door supporting member which is secured to the trolley. The track member may also include lip portions extending outwardly from the curved portions, and the substantially planar portions may define fastener receiving openings for bracket-less mounting of the track member to a supporting surface. With this construction, a self-cleaning, self-centering door track having integral mounting structure is provided.