PUMP

PROBLEM TO BE SOLVED: To provide a pump of an external liquid type having excellent sealing performance. SOLUTION: An outer cover 11 is provided to wrap a pump cylinder 4, a bellows 5 and an air cylinder part, hold the same in a space up to a pump body 3 in the direction of the central axis, and threadedly engage with the pump body 3 to be mutually fastened to each other in the direction of the central axis. Further, projecting parts 3f, 4d and recessed parts 4d, 5d are formed on the connecting part between the pump cylinder 4 constituting a pump action chamber of the external liquid type, the pump body 3 and the bellows 5, and mutually pressed in according to the fastening of the outer cover 11 and the pump body 3. COPYRIGHT: (C)2004,JPO&NCIPI