| 摘要 |
TROLLEY STOP FOR POWER AND FREE CONVEYORS A trolley stop assembly is provided for use in combination with a power and free conveyor system having a trolley member driven along a track by a drive mechanism. In the preferred embodiment, the conveyor system involved is an inverted power and free assembly wherein a trolley dog depends downwardly from each trolley. The preferred trolley dog is engaged by drive dogs on the drive mechanism, for pushing the trolley along the track; and, the preferred trolley dog is movable between upper and lower positions, for respective disengagement or engagement with drive dogs. The preferred assembly includes a stop arm pivotally mounted within the conveyor system for pivoting about a generally horizontal axis. Means are provided for lifting the stop arm into a first, upper, position wherein it can engage a portion of a trolley dog on a trolley to be stopped, to lift the trolley dog out of possible engagement with drive dogs. The preferred stop arm is elongate and includes a first, upper, cam surface with an abutment portion therein, providing for positive braking by mating with a portion of the trolley dog. An actuator mechanism includes a cam member engageable with the stop arm, to pivot same between upper and lower positions. The cam member is, preferably, actuated by a double-action piston and cylinder arrangement oriented generally against a side of the assembly. Means are provided for retention of the stop arm in an upper position, without maintaining substantial pressure in the cylinder. |
