Patent ID: 6554127
Filing Date: 2003-04-29
Classification: B61B

Abstract:
Power and free conveyor comprising:a) at least one free rail; b) at least one transport carriage, which comprises, in a direction of motion, a leading front runner and, in the direction of motion, a trailing rear runner, each of which is guided by the free rail, wherein the leading front runner and the trailing rear runner each have a pusher dog, which may adopt a stable higher driving position and a stable lower position of rest; c) at least one power rail, in which a power chain is guided, which carries a plurality of chain pusher dogs, which cooperate with the pusher dogs of the transport carriage in their driving position, in whichd) in at least one region of the path of motion of the transport carriages the power chain deviates from the course of the free rail in such a way that the chain pusher dogs are no longer in engagement with the front runner pusher dog and in said region the transport carriage is moved through interaction between the chain pusher dogs and the rear runner pusher dog; e) switchover devices are provided along the path of motion of the transport carriages at the locations, at which a change of the positions of the rear runner pusher dog is to occur, whereinf) the two positions of the rear runner pusher dog are stable positions in the sense that for a change between the two positions a resistance has to be overcome, for which purpose on the rear runner pusher dog a lug is formed, which cooperates with a spring, which comprises an offset end region and is fastened to the rear runner.