| CPC B62J 1/08 (2013.01) [B62J 2001/085 (2013.01)] | 14 Claims |
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1. An adjustable pneumatic-hydraulic pressure unit for stroke control, comprising:
a cylinder containing an outer tube, an inner tube, and an oil seal; the oil seal being sealed and fixed to the top of the outer tube and the inner tube, with an axial hole threading through the center of the oil seal;
an actuating tube sealed and combined with the oil seal and movably threaded through the axial hole for axial movement relative to the inner tube;
a first valve group sealed and fixed to the bottom of the outer tube; the inner tube, the inner surface of the outer tube, the outer surface of the inner tube, the oil seal, and the first valve group together forming an oil-gas mixing chamber; the first valve group being provided with a first oil passage internally communicating the oil-gas mixing chamber to an inner chamber defined in the inner tube and means for optional blocking the first oil passage; and
a second valve group fixedly attached to the bottom of the actuating tube and sealed and fixed to the inner surface of the inner tube; the inner surface of the inner tube, the outer surface of the actuating tube, the oil seal, and the top of the second valve group together forming an upper oil chamber, and the inner surface of the inner tube, the bottom of the second valve group, and the first valve group together forming a lower oil chamber; and the second valve group is internally provided with a second oil passage communicating the upper oil chamber and the lower oil chamber and means for optionally blocking the second oil passage.
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