Abstract: A fluid pump includes a press head portion, first and second unidirectional-valves, and extensible sleeve-pipe. Disposed in the press head portion, the first unidirectional-valve allows fluid to flow from its second end to its first end. The extensible sleeve-pipe includes a rebound element and outer and inner pipes which form a capacity-variable storage chamber. The inner pipe has a first end communicating with the first unidirectional-valve and a second end fitted to a first end of the outer pipe. The second unidirectional-valve allows the fluid to flow from its second end to its first end. The first end of the second unidirectional-valve communicates with the second end of the outer pipe. Upon contraction displacement of the inner pipe, the fluid flows from the storage chamber into the discharge passage via first unidirectional-valve. Upon expansion displacement of the inner pipe, the fluid flows into the storage chamber via second unidirectional-valve.

Abstract: A liquid pump capable of achieving pressure equilibrium includes a body, piston member, unidirectional input valve, unidirectional output valve, input inner-pipe, unidirectional gas-feeding hermetic-seal valve and input outer-pipe. The body has an input opening, output opening and piston opening. The piston member has a piston space communicating with the piston opening. The unidirectional input valve includes an input plug and input resilient element. The input plug abuts against the input opening. The unidirectional output valve includes an output plug and output resilient element. The output plug abuts against the output opening from outside. An input channel of the input inner-pipe communicates with the input opening. Direction of gas-flow between the unidirectional gas-feeding hermetic-seal valve and the input inner-pipe is opposite input direction of the input channel. The input outer-pipe has an input portion communicating with the input channel.

Abstract: A liquid pump capable of achieving pressure equilibrium includes a body, piston member, unidirectional input valve, unidirectional output valve, input inner-pipe, unidirectional gas-feeding hermetic-seal valve and input outer-pipe. The body has an input opening, output opening and piston opening. The piston member has a piston space communicating with the piston opening. The unidirectional input valve includes an input plug and input resilient element. The input plug abuts against the input opening. The unidirectional output valve includes an output plug and output resilient element. The output plug abuts against the output opening from outside. An input channel of the input inner-pipe communicates with the input opening. Direction of gas-flow between the unidirectional gas-feeding hermetic-seal valve and the input inner-pipe is opposite input direction of the input channel. The input outer-pipe has an input portion communicating with the input channel.