Dispensing – With discharge assistant – With movable nozzle interconnected therewith
Reexamination Certificate
1999-11-18
2001-03-20
Jacyna, J. Casimer (Department: 3751)
Dispensing
With discharge assistant
With movable nozzle interconnected therewith
C222S207000, C222S321200, C222S321300, C222S321800, C222S321700
Reexamination Certificate
active
06202896
ABSTRACT:
The present invention relates to a pump and to a receptacle fitted with such a pump and containing a liquid, for example a cosmetic cream.
BACKGROUND OF THE INVENTION
French patent 2 728 809 discloses a pump having a pushbutton mounted to move on a support which is secured to the receptacle containing the substance to be dispensed, the pushbutton comprising a circularly-cylindrical central duct having radial openings at its bottom end, the support defining around said duct an annular pump chamber of variable volume. A membrane made out of an elastomer is mounted on the support. The membrane has a circulary-symmetrical central portion in the form of a sleeve that is open at its top end and closed at its bottom end. The central duct of the pushbutton is inserted in the membrane until it bears against the end wall of the sleeve.
The membrane thus constitutes a resilient return member enabling the pushbutton to be brought back to its initial position after a quantity of substance has been dispensed.
In addition, during the return movement of the pushbutton the membrane isolates the pump chamber by pressing against the central duct, thus serving to prevent air from penetrating therein.
Such a pump has the advantage of comprising a small number of parts only and therefore of being relatively inexpensive to make.
Nevertheless, that prior art pump does not give entire satisfaction; the Applicant company has observed that the pushbutton tends to jam and/or that the quantity of substance tends to be irregular and poorly dispensed.
OBJECTS AND SUMMARY OF THE INVENTION
The present invention seeks to improve the reliability in operation of a pump of the type defined above, i.e. a pump of the type including a moving member mounted to move relative to a support, the moving member having a central duct in which substance to be dispensed penetrates via at least one opening, the support cooperating with the moving member to define, around said central duct, a pump chamber of variable volume, said pump also having a membrane with a central portion in the form of a sleeve that is open at its top end and closed at its bottom end, said central duct being inserted in said central portion, the membrane being organized to isolate the pump chamber from the opening(s) of said central duct while the volume of the pump chamber is increasing and substance is being sucked into it.
The invention achieves this by at least one of the membrane and the central duct being shaped to prevent a leakproof annular zone forming between the membrane and the central duct which would prevent the substance contained in the pump chamber from flowing via said central duct while the volume of the pump chamber is decreasing.
Preferably, at least one of the membrane and the central duct is shaped to bear against the other of the membrane and the central duct in predetermined locations of its periphery, at least during relative displacement between the moving member and the support.
Preferably, at least one of the membrane and the central duct has portions in relief against which the other one of the membrane and the central duct bears, at least during relative displacement between the moving member and the support.
By means of the invention, reliable operation of the pump is guaranteed, without the moving member jamming while the volume of the pump chamber is varying.
The above-specified portions in relief tend to prevent the membrane blocking the flow of substance coming from the pump chamber towards the opening(s) of the central duct and through which the substance to be dispensed penetrates while the volume of the pump chamber is decreasing.
These portions in relief also tend to hold the central duct of the moving member on the axis of the central portion of the membrane, which is favorable to satisfactory operation of the pump.
In a preferred embodiment, said portions in relief are made on the membrane, preferably being constituted by bulges that are uniformly distributed around the axis of the central portion of the membrane at its opening.
In a particular embodiment, the membrane has a flexible lip suitable firstly for isolating the pump chamber from a source of substance while the volume of said pump chamber is decreasing, and secondly to enable substance to penetrate into said pump chamber while the volume thereof is increasing.
In a particular embodiment, said flexible lip connects with said central portion of the membrane by forming a narrow annular groove that is downwardly open, and the support includes an inner skirt whose top end bears against the end wall of said groove to retain the membrane while the moving member is moving downwards to decrease the volume of the pump chamber.
In a particular embodiment the support has a double sealing lip bearing in leakproof manner against the tubular skirt of the moving member, the lip being downwardly open and extending concentrically around said central duct, said tubular duct defining the pump chamber in a radially-outward direction.
In a particular embodiment, said inner skirt forms a portion of a part fitted to the remainder of the support.
In a preferred embodiment, the above-mentioned flexible lip has an annular rib whereby it can press in leakproof manner against the inner skirt of the support while the volume of the pump chamber is decreasing or when the pump is at rest, said inner skirt communicating internally with the source of substance and including above said annular rib openings that enable the substance to penetrate into the pump chamber while the volume thereof is increasing and while said flexible lip is spaced apart from said inner skirt under the effect of the thrust from the substance flowing towards the pump chamber.
In a preferred embodiment, the flexible lip has a thin zone above said annular rib.
In a preferred embodiment, the central duct of the moving member is provided at its bottom end with at least one radial opening.
In a preferred embodiment, the moving member constitutes a pushbutton, said central duct being made integrally with a dispensing endpiece.
In a particular embodiment, the tubular skirt of the moving member slides inside a guide skirt of the support, said guide skirt co-operating with the inner skirt to form an upwardly-open annular groove communicating via at least one air intake orifice with the source of substance, the tubular skirt of the moving member bearing in leakproof manner against the guide skirt when the moving member is at rest and the volume of the pump chamber is at a maximum.
In a particular embodiment, the pump has a return spring for returning the moving member towards an initial position after a quantity of substance has been dispensed.
Advantageously, the return spring is constituted by a helical spring working in compression.
Preferably, the spring is disposed on the axis of the membrane so that the top end of the spring bears against the bottom end of the central portion of the membrane.
The presence of a return spring is advantageous since it makes it possible to have a wider choice of materials for constituting the membrane since the membrane need not be prestressed or it can be prestressed, but only to a relatively small extent.
The presence of a spring also enlarges the range of substance that can be dispensed, since it becomes easier to find a membrane material that is compatible with the substance for dispensing.
The invention also provides a receptacle fitted with a pump as defined above.
REFERENCES:
patent: 4029261 (1977-06-01), Olegnowicz
patent: 4452379 (1984-06-01), Bundschuh
patent: 4726747 (1988-02-01), Skorka
patent: 5638996 (1997-06-01), Montaner et al.
patent: 5655689 (1997-08-01), Fuchs et al.
patent: 5697530 (1997-12-01), Montaner et al.
patent: 5704519 (1998-01-01), Crosnier et al.
patent: 2 728 809 A1 (1996-07-01), None
Jacyna J. Casimer
L'Oreal
Oliff & Berridg,e PLC
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