| 摘要 |
In a walking beam type accumulating conveyor wherein workpieces upstream of an empty workpiece supporting station are transferred in a step-by-step fashion from station to station to fill the empty station and any empty stations upstream of it, the workpieces are lifted from each station for transfer to the next downstream station by workpiece carriers supported on transfer bars which themselves move vertically as well as longitudinally of the conveyor, and to render the conveyor most efficient the decision whether to pick up a workpiece at a station and transfer it to the next downstream station is made during elevation of the transfer bars and just prior to the carrier's engaging the workpiece. The transfer bars operate through a cycle of movement in which they are first raised to cause carriers on them to engage workpieces should the carriers be signalled to do so, then the bars are shifted longitudinally the distance between adjacent workpiece stations, then are lowered to deposit workpieces in workpiece supporting stations, and are then moved in the reverse longitudinal direction to the starting point of the cycle. The decision whether to lift a workpiece and transfer it is made during the elevation step of this cycle of movement.
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