Chain conveyor with vertical sections and selectively operating motors

A chain conveyor of the type carrying a plurality of loads and having a tractive motor with controlled speed and a plurality of virtually vertical and horizontal sections comprises in accordance with the present invention at the exit of each vertical section an intermittently operating motorized tractive sprocket (15) and a control device (18) connected to the motor of each motorized sprocket for actuation thereof and to selective consent means for actuation of said motorized sprockets, there being actuated by a load (13) a motorized sprocket at the beginning of the corresponding vertical section, whether ascending or descending, and said sprocket being deactuated at the end of said vertical section to allow traction of said sprocket as it idles. The tractive chain is thus subjected at the most to a traction virtually comparable to the force necessary to lift a single load. The tractive motor (12) can also be commanded to rotate at a higher speed when no load is at the vertical sections than when a load is traveling over one of said sections.