A power and free conveyor transfer system includes a number of drive trolleys operating within a free track and being selectively propelled by endless drive chains within a vertically aligned power track. Each drive trolley includes a trolley housing body to which are rigidly attached a pair of downwardly extending lateral arms, each with a rearward facing drive surface. A pivotable drive member is attached to the front end of the trolley housing and extends backward and downward between the lateral arms with a drive dog forming a portion thereof. The drive trolley design facilitates transfer of each drive trolley between non-synchronous delivering and receiving power tracks in a conveyor transfer zone. Within the transfer zone, the delivering and receiving power tracks are at different elevations and approach each other from a relatively large angle to minimize the potential for mechanical interference or jamming.

A conveying system (10) for workpieces or objects, comprising a guide profile (14), conveying carriages (12) which can be moved along the guide profile (14) and in each case have a holding unit, in particular a pallet (58) or gondola, for at least one workpiece or at least one object, a first form-fitting unit (20) which can be moved substantially parallel to the guide profile (14) by means of a drive assembly (52), and a first mating form-fitting unit (22) which is respectively mounted on each conveying carriage (12) and can be coupled to the first form-fitting unit (20), is characterized by a first coupling unit (26), by means of which the coupling of the first form-fitting unit (20) to the respective first mating form-fitting unit (22) can optionally be engaged and disengaged, a stationary second form-fitting unit (30) running substantially parallel to the guide profile (14), a second mating form-fitting unit (32) in each case mounted on each conveying carriage (12) such that it can be coupled to the second form-fitting unit (30), and a second coupling unit (36), by means of which the coupling of the second form-fitting unit (30) to the respective second mating form-fitting unit (32) can optionally be engaged and disengaged.

The invention relates to an overhead conveyor of the type that comprises at least one drive carriage (13) which is drivably arranged in a girder system and from which load-holding means (18) are suspended, and where the girder system comprises an elongate straight box girder (9) having a first inner space with rails (12) for the drive carriage (13) and a second elongate inner space comprising a driven endless belt (5, 6) with means (23) to be drivingly connected to the drive carriage.(13).

A conveyance system, wherein dividable horizontal conveyance units are connected to each other through joint plates and a support post and rails of the horizontal conveyance units are connected to each other without any step and clearance. A joint conveyance carnage assembly is conveyed by a force applied thereto from annular chains of the horizontal conveyance units through chain presser plates. When the rearmost one of the chain presser plates leaves the annular chain of the horizontal conveyance unit, the chain presser plate of the headmost first conveyance carriage reaches the annular chain of the horizontal conveyance unit and the joint conveyance carriage assembly is continuously conveyed.

A two-track conveyor system includes an I-beam-shaped power track and a channel-shaped free track, where the power track supports a heavy-duty chain drive having a pusher dog with a pivotal connector. By providing the pusher dog with the pivotal connector the pusher dog can be used with a load-bearing trolley, that rides within the free track, that has a fixed power dog at the front end of the leading trolley and that does not require a hold back dog.