An emulsion pump mainly comprises a piston rod, a pressing head, a screw-topped
sleeve, a cylinder, a spring, a rubber pipe and a gasket. Among them, the upper
screw thread of the cylinder engages with a screw thread portion of the screw-topped
sleeve. The width of the teeth of the upper end screw thread of the cylinder is
A, the width of the gullet the screw thread portion of the screw-topped sleeve
which is connected with the screw thread of the cylinder is B, and B is greater
than A, thereby a gap exists between them; in addition, a gap is also formed between
the contact surface of the upper end of the cylinder and the lower surface of the
top portion of the screw-topped sleeve, thereby an air channel for preventing liquid
entrance is formed in the emulsion pump.
