| 摘要 |
A fluid pressure operated reciprocating conveyor in the form of a pan feeder comprises a base, an elongated conveyor trough reciprocably mounted on the base, a drive cylinder connected between the base and trough, a constant volume pump, a solenoid-operated reversing valve connected between the pump and the drive cylinder to direct pressure fluid to opposite ends of the cylinder to reciprocate the trough through a stroking range in a forward stroke and in a rearward stroke at a substantially higher speed than the forward stroke. Forward and rearward limit switches connected to the reversing valve are automatically operable by the moving trough to reverse the drive cylinder at opposite ends of the stroking range. A relief valve connected to the drive cylinder is effective during the initial portion of the forward stroke to direct pressure fluid from the drive cylinder at a diminishing rate and thereby accelerate the forward stroke of the trough during that initial portion of the stroke to convey material with the trough. The reversing valve is also effective at the terminal end of the forward stroke to apply a sudden, rearward shock load on the trough to break the frictional engagement with the material and enable the material to slide forwardly while the trough is in its rearward stroke. One embodiment uses a single-rodded piston and a pump with one constant volume output. Another embodiment uses a double-rodded piston and a pump with both low and high constant volume outputs alternately applied to the cylinder during the forward and rearward strokes respectively.
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