Patent ID: 8403181

Claim:
A water-ingress-preventing mechanism for a lotion pump, comprising: a press head, in which a passage is formed, a locking tube portion being formed around a lower end opening of the passage and vertically extending downwards from a body of the press head, an external thread being formed on an outside wall of the locking tube portion; a connecting conduit, an upper end of which is fixed to the lower end opening of the passage of the press head so as to communicate with the passage; and a cylinder cover, which has a central through-hole for the connecting conduit to pass, a water-ingress-preventing guide sleeve being provided on an inside wall surface of a lower portion of the central through-hole to vertically extend beyond a top surface of the cylinder cover, the fit between an inside wall surface of the water-ingress-preventing guide sleeve and an outside wall surface of the connecting conduit being a slide fit with a clearance therebetween, the clearance providing a fluid communication between an interior of a container on which the lotion pump is mounted and the atmosphere, an annular recess for the locking tube portion to thread in being formed between an outside wall surface of the water-ingress-preventing guide sleeve and an inside wall surface of an upper portion of the central through-hole, an internal thread being formed on an inside wall of the central through-hole opposite to the outside wall surface of the water-ingress-preventing guide sleeve, the internal thread being able to engage the external thread on the locking tube portion so as to lock the press head relative to the cylinder cover, wherein the press head has an upper stop position and a lower stop position of a press stroke with respect to the cylinder cover, the lower stop position of the press stroke being defined by a position at which a lower end of the external thread of the locking tube portion abuts against an upper end of the internal thread of the central through-hole during a press stroke of the press head, and wherein at least one longitudinal slot is formed in the locking tube portion, extending at least a part of a length of the locking tube portion from a lower end edge of the locking tube portion, and is disposed such that an upper end of the slot is at a position above the top surface of the cylinder cover when the press head is in the lower stop position relative to cylinder cover.