Fluid dispenser pump

#The present invention relates to a fluid dispenser pump, and to a fluid dispenser device including such a pump. More particularly, the present invention is applicable to dispenser devices in which the fluid is kept without any preservative, so that it is important to remove any risk of said fluid being contaminated while the device is being stored and/or while it is being used.

#Such preservative-free dispenser devices are well known, and they fall into two distinct categories. Firstly, there are “airless” devices with no air intake, in which the fluid is generally kept in a flexible reservoir whose volume decreases as the fluid is dispensed. Secondly, there are devices with air intakes, in which case the air taken into the device or the pump must be filtered to prevent any bacteria, germs, or other elements that are harmful to the fluid from entering it. Document FR-2 798 368 discloses such a pump and such a device.

#Unfortunately, it has been observed that bacteria or germs can enter the device via a path other than the intake air path, in which a filter is generally provided. Thus, in most pumps, and in particular the pump disclosed in FR-2 798 368, the actuating rod is mounted to slide against an element of the pump (generally a ferrule) used to define the rest position for the pump. That contact between the actuating rod and the ferrule is not necessarily leaktight, since the sealing of the pump is provided at the piston, which is secured to or integral with the actuating rod. In some cases, it is possible that germs or bacteria might penetrate into the pump through that route, i.e. via the interface between the ferrule and the actuating rod. When the pump is in the rest position, the piston of the pump forms a leaktight seal with the bottom end of the ferrule, but when the pump is in the actuating position, that seal no longer exists, so that, during actuation, any germs or bacteria can penetrate more deeply into the pump body, so that they can ultimately come into contact with the fluid contained in the pump chamber.

#The advantages and characteristics of the present invention will appear more clearly on reading the following detailed description of an embodiment of it, given with reference to the accompanying drawing which is given by way of non-limiting example, and in which:

#FIG. 1 is a diagrammatic section view of a fluid dispenser pump 1 of the present invention; and

#FIG. 2 is an enlarged diagrammatic view of a detail of FIG. 1.

#With reference to FIG. 1, the fluid dispenser pump 1 includes a pump body 10 in which a piston 20 is mounted to slide in leaktight manner. The piston 20 is connected to an actuating rod 30, the piston advantageously being integral with the rod. The pump body 10 is generally assembled onto the neck of a reservoir (not shown) by means of a fixing element 2, such as a ring or a cap, which may be of arbitrary type, and in particular snap-fastenable, screw-fastenable, or crimpable. Sealing between the pump 1 and the fixing element 2 is provided by means of an annular gasket 50, and sealing between the fixing element 2 and the reservoir (not shown) is provided by means of a neck gasket 55. The pump 1 may be pre-assembled in the fixing element 2 to form a dispenser assembly.

#In the invention, the sealing gasket 50 is in continuous leaktight contact with the actuating rod 30. Thus, the actuating rod 30 rests in leaktight manner against said sealing gasket 50 when the pump is in the rest position (shown in FIG. 1), and slides in leaktight manner against said sealing gasket 50 while the pump is being actuated. This implementation guarantees that the contact between the pump and the actuating rod 30 is leaktight so that it is impermeable to the fluid, to air, and to bacteria or germs. It is therefore impossible for germs or bacteria to penetrate into the pump 1.

#In the embodiment shown in the figures, the pump 1 includes a ferrule 40 which is assembled in the pump body 10, in particular at the top edge of said body, to define the rest position for the pump. In which case, the gasket 50 may be assembled onto said ferrule 40.