Patent ID: 6890162

Claim:
An emulsion pump having an air channel preventing liquid entrance, comprising: a piston rod having an upper one-way valve; a pressing head being fixed on the upper end of the piston rod; a screw-topped sleeve having a central through hole and a screw thread portion; a guide sleeve, wherein the guide sleeve is integrally formed on a lower wall of the central through hole, an inner wall of the guide sleeve preventing the liquid entrance slidably matches with an outer wall of the piston rod; a cylinder having an upper screw thread which is connected to the screw thread portion of the screw-topped sleeve, wherein a lower one-way valve and a spring are provided in the cylinder; a rubber pipe having an upper end which is fixedly connected with a lower end of the cylinder; a gasket, which is arranged on an upper end of an outer side of the cylinder and abuts tightly against a lower surface of an inner side of the screw-topped sleeve; wherein a width of teeth of the upper screw thread of the cylinder is A, a width of a gullet of the screw thread portion of the screw-topped sleeve which is connected with the upper screw thread of the cylinder is B, and B is greater than A, and gaps therebetween forming a portion of the air channel of the emulsion pump, and a gap is disposed between contact surfaces of the upper end of the cylinder and a top lower surface of the screw-topped sleeve.