LIQUID FORCE-FEEDING PUMP

PROBLEM TO BE SOLVED: To effectively adjust pressure in a pump chamber, by providing pressure vibrating means by which the capacity of a pressurizing chamber is periodically changed at a constant amplitude for the purpose of vibrating under pressure operating fluid filled into a closed capacity chamber and capacity variable adjusting means for adjusting the capacity of the closed capacity chamber. SOLUTION: A clearance between a rubber tube 5 and a silicon tube 4 is adjusted so that pressure of physiological saline in a pump chamber 3 is adjusted, according to the magnitude of pressure of operating fluid by the capacity change of a pressurizing cylinder 13 accompanied by the forward and rearward movement of a variable capacity piston 14a. The capacity of the pressurizing cylinder 13 is repeated to be increased and decreased by the reciprocating movement of a pressurizing piston 15a under such a condition that the rubber tube 5 and the silicon tube 4 are tightly stuck to each other. Hereby, pressure vibration applied to a pressure transmission chamber 6, is transmitted to the pump chamber 3 through a tightly sticking part between the rubber tube 5 and the silicon tube 4, and the physiological saline is successively sucked in and delivered from the pump chamber 3.