Patent ID: 8333274

Claim:
A sorting system including a conveyor comprising a plurality of carts for carrying articles, a track along which the carts may be driven, a propulsion system for providing a driving force to the carts for moving the carts along the track, said propulsion system comprising at least one stationary stator having a plurality of coils arranged to generate magnetic fields when electrical power is applied, and reaction elements mounted on each of the carts, said reaction elements each comprising a plurality of permanent magnets connected to at least one plate-like carrier, and said reactions elements being arranged on the carts in order to interact with the magnetic fields generated by the coils of the stator, as well as a controller for controlling a supply of electrical power to the stator in order to provide a driving force via the reaction elements to the carts when power is applied, where the reaction elements each comprises a number of permanent magnets arranged with alternating polarity and with an equal pitch from magnet to magnet, and where the coils of the stator are arranged with a pitch from coil to coil equal to the pitch from magnet to magnet on the reaction element, and where each cart is linked to an adjacent cart, and where the magnets on reaction elements of two adjacent carts are arranged to form a row of magnets with constant pitch and alternating polarity, said row having an only interruption where one magnet is absent, said interruption being located by a transition between said two adjacent carts.