Fluid dispenser pump

#The present invention relates to a manually-actuated fluid dispenser pump, and to a fluid dispenser device including such a pump.

#In known manner, a fluid dispenser pump generally includes a pump body in which a piston is mounted to slide between a rest position and a dispensing position. When the pump is a metered dose pump, i.e. a pump that dispenses accurate and identical metered quantities or “doses” each time it is actuated, the pump body can contain a pump chamber that is generally defined between an inlet valve and an outlet valve. In which case, it is essential for the outlet valve to be leaktight during actuation so as to avoid any leakage before the end of actuation, and, similarly, the leaktightness of the inlet valve must also be excellent in order to avoid any of the fluid contained in the pump chamber flowing back into the reservoir during actuation. Another problem that can arise relates to priming, i.e. to removing the air contained in the pump chamber before the pump is actuated for the first time. In certain pumps, the air is removed via the outlet valve towards the dispensing orifice. That solution is not always su-table when the device is provided with closure means for closing off the dispensing orifice, and in particular when such closure means prevent the air from being removed during priming. Another solution consists in providing a hole in the pump body and in removing the air through said hole. Unfortunately, that solution makes it necessary to provide means for closing off the hole after priming, which can make the structure of the pump relatively complex.

#An object of the present invention is to provide a fluid dispenser pump that does not suffer from the above-mentioned drawbacks.

#Other characteristics and advantages of the present invention will appear more clearly on reading the following detailed description of two embodiments of it, given with reference to the accompanying drawings which are given by way of non-limiting example, and in which:

#FIG. 1 is a diagrammatic section view of a pump in a first embodiment of the present invention, in the rest position;

#FIG. 2 is a view similar to the view in FIG. 1, in the priming position;

#As shown in the figures, the pump of the present invention includes a pump body 10, in which a piston 50 is mounted to slide between a rest position (shown in FIGS. 1 and 4), and a dispensing position (shown in FIGS. 3 and 6). The piston 50 is connected to and preferably integral with an actuating rod 60 on which the user exerts an axial force, e.g. by means of a pusher (not shown) or of a dispensing head (not shown). The actuating rod 60 may be hollow, and it is generally provided with an expulsion channel 65 making it possible to expel the fluid. The pump body 10 contains a pump chamber 20 defined between an inlet valve 30 and an outlet valve 40. The inlet valve 30 includes an inlet valve element 31 that co-operates with the pump body 10 or with an element secured to or integral therewith to define the open and the closed positions for said inlet valve 30. Similarly, the outlet valve 40 includes an outlet valve element 41 which co-operates with the actuating rod 60 (or with an element secured to or integral therewith) to define the open and the closed positions for said outlet valve 40. The inlet valve element 31 and the outlet valve element 41 are both mounted to move inside the pump body 10. The pump of the invention may be fitted to a reservoir (not shown) by means of a fixing ring 1 which may be of any type, in particular screw-fastenable, crimpable, or snap-fastenable. Generally, a sealing gasket 5 is interposed between the top edge of the reservoir (not shown) and the fixing ring 1. A dispensing head or pusher is then assembled to the pump for the purpose of actuating it, thereby forming a manually-actuated fluid dispenser device.

#In the invention, the outlet valve 40 is urged into its closed position by the pressure from the fluid contained in the pump chamber 20. This guarantees that there is no risk of any leakage while the pump is being actuated since, as soon as the user actuates the pump, pressure is generated inside the pump chamber 20, and this pressure urges the outlet valve 40 into its closed position, thereby enhancing leaktightness at said outlet valve. Similarly, the inlet valve element 31 co-operates with a portion of the pump body 10 that is formed such that the pressure from the fluid contained in the pump chamber 20 also improves the leaktightness of said inlet valve 30. When the piston 50 reaches its dispensing position, the inlet valve element 31 co-operates with the outlet valve element 41 to move it mechanically into the open position of the outlet valve 40. The outlet valve being opened mechanically in this way at the end of the pump actuating stroke guarantees that a dose is dispensed in full each time the pump is actuated.

#Advantageously, the inlet valve element 31 comprises a bottom hollow axial sleeve 32 and a top hollow axial sleeve 34. The bottom axial sleeve 32 is mounted to slide in leaktight manner around a hollow axial tube 12 that is secured to or integral with the pump body 10. As shown in the figures, the axial tube 12 may be made integrally with the pump body 10, and may be disposed concentrically inside said pump body, at the bottom edge thereof. Sealing is provided at the bottom end 33 of said bottom sleeve 32, and this sealing is thus improved while the pump is being actuated by the pressure from the fluid contained in the pump chamber 20, the fluid spreading around said bottom sleeve 32 of the inlet valve element 31. When the pump is in the rest position, as shown in FIGS. 1 and 4, the bottom end 33 of said bottom sleeve 32 is spaced apart from the top end 13 of said axial tube 12, thereby defining the open position for the inlet valve 30, by opening up a passageway through which the fluid can flow into the pump chamber 20.