Dispensing – Resilient wall – With flow controllers or closures
Reexamination Certificate
2001-02-09
2003-04-15
Mancene, Gene (Department: 3754)
Dispensing
Resilient wall
With flow controllers or closures
C222S207000, C222S490000, C222S494000, C137S512000
Reexamination Certificate
active
06547106
ABSTRACT:
The present invention relates to a pump intended for dispensing a liquid or semi-liquid product, particularly a cosmetic or dermo-pharmaceutical product. Such a product may be in the form of a milk, an emulsion, a gel, or a cream. The invention also relates to a device for containing and dispensing a product including such a pump.
U.S. Pat. No. 3,973,700 discloses a sprayer having a body obtained by molding a plastic or a rubber. The body contains a chamber and has a pump including a bellows piston assembly. The bellows allows the volume of the chamber to be varied. The body also contains a nondeformable portion located opposite the bellows, in which two orifices are formed. The orifices are closed off by two flaps obtained by molding with the body. In the closed position, the flaps rest on a seat formed by the edge of the orifice with which they are associated. One of the flaps is formed inside the chamber, and the other is formed outside the chamber. Because of the configuration and positioning of the flaps, the body is molded in the open position, and is closed when mounted on the pump. This configuration poses sealing problems in the chamber closure region, making the fitting of such a pump appreciably more complicated.
Furthermore, because of demands associated with the molding of such flaps, the flaps are positioned in such a way that their one-way operation is not optimal. In particular, the inlet flap is arranged on a wall directed at approximately 45° with respect to the direction of the actuating force that has to be exerted on the bellows-forming part via a trigger. This arrangement carries the risk of opening slightly under the effect of a raised pressure in the chamber, thus appreciably minimizing the performance of such a pump.
Other bellows-type mechanisms are known, for example, International Application No. WO 95/00253 and U.S. Pat. No. 5,829,640. In these documents, the inlet and outlet orifices are closed by flaps in the form of attached elements separate from an elastically deformable part that forms at least part of the chamber. This arrangement results in a pump that is complicated to fit and expensive to implement.
A pump having a portion of rubber that is formed by assembling two or more parts, is described in U.S. Pat. No. 2,772,817. The pump disclosed in this reference may suffer from one or more of the disadvantages described above.
According to one aspect of the invention, a pump may include a single-piece vessel of unitary construction defining a variable-volume chamber. The vessel may include a first wall and a second wall. The first wall may include an inlet slit formed therein, and the second wall may include an outlet slit formed therein. The inlet slit may be configured to open one way in response to a decreased pressure in the chamber, and the outlet slit may be configured to open one way in response to an increased pressure in the chamber.
In one embodiment, the vessel may be configured to deform from a first position occupying a first volume to a second position occupying a second volume in response to a pressure applied to the vessel. The first volume may be a maximum and the second volume may be a minimum. Optionally, the pump may include an actuating member configured such that a pressure on the actuating member transmits the pressure to the vessel.
The vessel may be formed, for example, in its entirety from a single molded piece of material in which the inlet and outlet slits are formed, for example, by cutting or molding.
According to another aspect of the invention, a pump for use with a device for containing and dispensing a product may include a body member and a vessel mounted on the body member in a partially-compressed or deformed, first position (i.e., different from a non-compressed, rest position). The vessel may define a variable-volume chamber and may include a first wall and a second wall. The pump may also include an inlet slit on the first wall and an outlet slit on the second wall. The inlet slit may be configured to open one way in response to a decreased pressure in the chamber, and the outlet slit may be configured to open one way in response to an increased pressure in the chamber.
Within the meaning of the present invention, the term “slit” may denote an opening obtained by cutting or molding, and of which the edges that delimit the opening are capable of closing it in a substantially sealed manner. In the case of a slit formed by cutting, the cut may be made at right angles to a plane including the wall of the vessel having the slit (i.e., the plane of the slit). Alternately, the cut may be made at another angle. Such a slitted structure may differ from a structure disclosed in U.S. Pat. No. 3,973,700, in which each of inlet and outlet openings consists of a hole having edges that are not capable of closing the opening, but instead form a seat for a flap molded over the plane of the hole, wherein the surface area of the flap is greater than the surface area of the hole.
When the slits of the invention are in the closed position, the edges of the slit may be configured more or less contiguously (i.e., substantially butted up) such that the slits should seal the product off. Thus, in the case of a product of high viscosity, sealing may be achieved in spite of edges that are not completely contiguous. Conversely, in the case of products of low viscosity, contiguous edges may be needed. Optionally, the slit may also be airtight so as to make the pump easier to prime. The substantially contiguous slit arrangement, with the edges abutting more or less tightly in the closed position, may be enhanced by subjecting the slit to a lateral load, that is, one parallel to the plane of the slit.
The edges of such a slit may be capable of parting at right angles to the plane of the slit so as to open the slit in response to a pressure exerted on one side of the slit by the product that is to be dispensed. The edges may return to their closed position when the pressure ceases. When pressure is exerted on the other side of the slit, the edges delimiting the slit may come into abutment against one another to oppose the opening of the slit. The one-way nature of the slit can be obtained by preforming and/or loading the edges of the slit in such a way as to give them an orientation, with respect to a plane substantially including the wall in which the slit is made, that determines the direction in which the slit opens. For example, the slit may be biased closed by preloading the wall of the vessel with a lateral preload.
The slit may be of any shape. For example, the slit may be of elongate shape, or in the shape of a cross or of a star.
Thus, by making the inlet and outlet orifices in the form of slits, a structure may be achieved that can be molded directly in the required shape to form the vessel, that is, in the form of a closed volume in which all that will be necessary will be for the slits to be made, for example, by cutting. The vessel may thus be mounted on the pump body member without the need to produce sealing, other than at the point where the vessel is itself mounted on the body member and where an actuating member is mounted on the vessel.
Optionally, the vessel may be molded in the form of a closed structure in which the inlet and outlet slits are cut. This characteristic, relating to molding in the form of a closed volume, makes it possible to reduce the amount of sealing that has to be achieved when fitting the pump.
By way of example, the vessel may be molded in the form of a cylinder of revolution having two closed ends. One slit may be cut essentially at the center of each of the ends. A structure such as this can be obtained by rotary molding. The cross section of the vessel may be circular, a square, triangular, hexagonal, or another appropriate shape.
The vessel may be elastically deformable, for example, because of its configuration, such as in the form of a bellows, or because of the material of which it is made, such as an elastomeric material, or for both reasons. Thus, the vessel can return to the first po
Bul Thach
Finnegan Henderson Farabow Garrett & Dunner
L'Oreal (S.A.)
Mancene Gene
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