Plant for sorting items, with self driven carriages

A conveyor system for use in sorting items, comprising:

• a pair of uniformly-spaced side rails, each side rail having, in axial section, a substantially-vertical upright portion and a substantially-horizontal transverse portion projecting from one side of the upright portion toward the other side rail;
• a central rail substantially-centrally between the side rails and lower than the side rails, the central rail having a T-shaped axial section comprising oppositely-projecting transverse webs, each transverse web having a top and a bottom and an edge opposite that of the other transverse web therebetween;
• at least two carriages having coupling means for jointedly linking the carriages in tandem, each carriage comprising a freely-rotatable first wheel on one side for movement along the transverse portion of one of the side rails, two non-coaxial pairs of freely-rotatable second wheels on the other side, each pair of the second wheels engaging opposite side of the upright portion of the other of the side rails, two non-coaxial pairs of freely-rotatable third wheels engaging opposite sides of the transverse portion of the same side rail as engaged by the second wheels, belt means comprising a rotatable belt having an uppermost run defining a conveyor plane for items to be sorted and belt-rotating means for rotating the belt with the uppermost run moving toward one of the sides of the carriage for discharging the items from the conveyor plane;
• a motor unit for running along the cental rail, the motor unit comprising a frame, a pair of freelyl-rotatable wheels having horizontal axes for running on a top and a bottom of the transverse webs of the central rail, a pair of freely-rotatable reference wheels spaced from the latter for respectively acting on the tops of the transverse webs, two pair of freely-rotatable wheels having spaced vertical axes for running on the edged of the transverse webs, a motor-transmission group comprising a motor and a transmission therefor, an elastic mount oscillatorily securing the motor-transmission group to the frame with the motor on one side of the elastic mount in the direction in which the vertical axes of the two pair of wheels of the motor unit are spaced, the transmission comprising drive wheels rotated by the motor respectively acting on the bottoms of the transverse webs on the opposite side of the elastic mount from the motor, whereby the torque exerted by the weight of the motor keeps the drive wheels constantly pressed up against the transverse portions of the central rail;
• and
• a union bar having a hinge at each end respectively connected to one of the carriages and the motor unit, whereby the one carriage is a drive carriage and the other is a driven carriage.