An apparatus for transferring carriers from a first power line to a second power line through a power line discontinuous section. Each carrier has a dog engageable with each of the pivotable pushers on each of the power lines and a pusher raising cam having a dog receiving recess at its rear portion. The pusher includes a downward portion and a laterally extending horizontal portion at the lower end of the downward portion, the horizontal portion being formed with an upper pushing face and a lower pushing face on its front side and having a cavity in its bottom at the middle of the length thereof. The cam has a front lower portion, a rear higher portion having its top positioned at the same level as the top of the dog and a projection on the top of the front lower portion. The free line has a carrier standby section coextensive with the first power line near the discontinuous section and longer than the carrier. The standby section is laterally displaced from immediately below the first power line within a range permitting the horizontal portion of a pusher advancing from behind a carried at rest in the standby section to engage the projection of the cam on the carrier upon disengagement from the dog on the following carrier to transfer the standby carrier to the discontinuous section, after allowing the follower to stop in lapping relation to the preceding carrier.

A power and free conveyor system wherein a plurality of conveyor units or trolleys in the form of part suspension frames and the like may be moved by a continuously moving chain but the relationship of the chain to each conveyor is such that no latching or unlatching of the units is necessary to stop a particular unit at a station or when a stack-up of conveyor units occurs. Resumption of motion occurs automatically when intentional stopping or stack-up is relieved. The drive chain engages a plurality of freely rotating sprockets arranged on the trolley in a manner in which the chain forms a loop diverging from the general alignment of the chain. The acceleration and drive of the trolleys is thus controlled by a variable tension arrangement on one of the drive sprockets of the chain.

An overhead conveyor system with rolling conveyor carriages guided on rails. The pushers provided for moving the conveyor carriages out of the main track and onto a secondary track are provided with a claw which can be swung in a direction opposite to the direction of transport (T) into an upward-swung third position. In this position, a conveyor carriage which is blocked in the region of a switch and cannot be moved out of the track can be passed by the pusher without damage to the conveyor carriages or the overhead conveyor system. When the claw is swung upward, a flap is at the same time moved out laterally, which can serve as a signal for immediately stopping the conveyor system. The outwardly swung flap may assist maintenance personnel in finding the switch at which a conveyor carriage cannot be properly moved out of the line. The pusher includes a recess which is covered by a spring-loaded plate. The claw is fastened asymmetrically in the pusher so that it swings upward into the recess. The claw is urged into its lowest position by a spring above the plate. A force acting on the claw and swinging it into its third position causes the claw to move against the plate as the force becomes larger than the effective force of the spring.

In a power-and-free conveyor including a first free rail, a second free rail branching off from the first free rail, a first and a second power rail provided above the free rails respectively, a transfer system for transferring the carriers movably supported by the first free rail to the second free rail. An auxiliary rail attached to the first of the free rails slightly projects above the first free rail and has a cutaway section of requred length to the rear of the branching point of the second free rail. The carrier has at its front portion a pair of tilting drive and back-up dogs engageable with the propelling member driven along the power rail and at its rear portion a propelling member raising cam member. When a carrier advances into the cutaway section, a raising plate disposed near the front end of the rail cut-away portion, disengages the propelling member from the tilting drive dog on the carrier. A following propelling member advancing behind the disengaged propelling member engages under the cam member on the carrier in the cutaway section to push the carrier from behind and to advance the carrier to the second free rail. When the rear portion of the carrier approaches the branching point, the pushing propelling member ascends an upwardly slanting disengaging edge of the auxiliary rail at the front end of the cutaway section and is thereby disengaged from the carrier.

A system for moving a tele-operated car containing electrical equipment is disclosed herein which comprises a drive mechanism, a trolley chain continuously driven by the drive mechanism, a railway disposed along the trolley chain, a tele-operated car with a sprocket wheel engaging the trolley chain and a rail wheel engaging the railway, and a generator in the car for supplying electric power to the electrical equipment. The generator is selectively driven by the sprocket wheel when the car is stopped or the rail wheel when the car is moving.