Patent Publication Number: US-6217808-B1

Title: Method of manufacturing an improved valve for a device for packaging and dispensing a substance stored under pressure

Description:
This is a Division of application Ser. No. 08/644,061 filed May 9, 1996, now U.S. Pat. No. 5,895,029. The entire disclosure of the prior application(s) is hereby incorporated by reference herein in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to devices for packaging and dispensing a substance, in particular a cosmetic, and more precisely the invention relates to a valve for fitting to a device that comprises a receptacle suitable for containing the substance and for storing it under pressure. The valve is of the type comprising an actuator rod and a valve body. The actuator rod has a passage through which the substance to be dispensed passes. The valve includes closure means suitable for being held in the receptacle by the valve body and suitable for closing said passage, and the actuator rod can be displaced inside the valve body between a first position in which said closure means close said passage, and a second position in which said passage is released to enable the substance to be dispensed. The valve also comprises resilient return means for returning the rod to said first position. 
     BACKGROUND OF THE INVENTION 
     Patent FR 2 035 669 proposes a valve of the above-specified type that comprises inclined flexible fins integrally molded with the actuator rod and designed to exert a resilient return force urging the rod into a closure position. An advantage of that type of valve, which is made entirely out of plastics material, is the absence of any metal parts in contact with the substance to be dispensed. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     An object of the invention is to further improve a valve of the above-specified type, in particular making it easier to mount the valve on the receptacle of the packaging and dispensing device. 
     The invention achieves this object by the fact that said resilient return means comprise at least one bridge of material interconnecting the actuator rod and the valve body, suitable for deforming resiliently and suitable for urging the actuator rod into said first position, the valve body, the actuator rod, and said bridge of material being made by a dual-injection molding technique, the body and the rod being made of a first plastics material and the bridge of material being made of an elastomer, second plastics material, said plastics materials being selected in such a manner that said bridge of material can be assembled to the rod and the body by local melting of the material during molding. 
     The invention makes it possible to obtain a valve whose structure is relatively simple and compact, unlike known valves that are integrally molded using a single plastics material. The handling and installation of a valve of the invention in the receptacle of the packaging and dispensing device are made easier. 
     In an embodiment of the invention, said bridge of material is constituted by a portion of a disk fixed via a single face to the bottom end of the valve body and to the bottom end of the actuator rod. Advantageously, the disk includes openings between annular regions respectively in contact with the actuator rod and the valve body, and it is shaped so as to be pre-stressed when said actuator rod is in said first position. 
     In an embodiment of the invention, the valve body has an annular projection on its periphery suitable for being retained by crimping in the receptacle. 
     The invention also provides a method of manufacturing a valve as defined above, and a packaging and dispensing device fitted therewith. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     Other characteristics and advantages of the present invention appear on reading the following detailed description of a non-limiting embodiment of the invention, and on examining the accompanying drawing, in which: 
     FIG. 1 is a diagrammatic axial section view of a valve constituting an embodiment of the invention, installed in a receptacle of a packaging and dispensing device; 
     FIG. 2 shows in front view and in isolation the disk interconnecting the actuator rod and the valve body; 
     and 
     FIG. 3 is a diagrammatic axial section showing in isolation the valve body, the actuator rod, and the disk interconnecting them in the position in which they are molded. 
    
    
     MORE DETAILED DESCRIPTION 
     The valve  1  of the invention as shown in FIGS. 1 to  3  is fitted to a receptacle of a packaging and dispensing device suitable for storing a cosmetic under pressure. The receptacle comprises a conventional tubular body (not shown) that is elongate along a longitudinal axis X (lying in the section plane of FIG. 1) and that is closed at one end. The body is open at its opposite end and it receives a cap  2  that is also known per se. The cap  2  is for fixing on the body and has an annular groove  3  around its periphery for crimping on the open end edge of the body, which groove is provided internally with a sealing gasket  4 . The center of the cap  2  has a housing  5  for receiving the valve  1 . The housing  5  is radially defined by a wall  6  that is circularly cylindrical about the longitudinal axis X. This wall  6  is extended by a generally plane wall  7  that is perpendicular to the longitudinal axis X, and pierced in its center by a hole  8 . The cap  2  may be cut and stamped from a metal disk. 
     The valve  1  has a valve body  9  and an actuator rod  10  capable of being displaced therein along the longitudinal axis X. The rod  10  passes through the hole  8  of the cap  2 . A passage is formed along the rod  10  to convey the substance that is to be dispensed towards the outside. This passage is formed by uniting a blind bore  11   a  extending along the axis X and a through hole  11   b  extending radially. The bore  11   a  opens out in the end edge  12  of the rod  10  situated outside the receptacle. The hole  11   b  opens out at its radially inner end close to the bottom  13  of the bore  11   a , and at its radially outer end, either to an annular sealing gasket  14 , or else further down inside the receptacle, as ,specified below and depending on the position of the rod  10 . 
     The rod  10  has an outside shoulder  15  and reference  10   a  designates the rod portion situated to one side of the shoulder  15  that is engaged in the hole  8 , while reference  10   b  designates the rod portion situated on the opposite side thereof and that extends inside the receptacle. A blind bore extending along the axis X is formed in the portion  10   b  of the rod so as to avoid wasting material. 
     The above-mentioned gasket  14  presses against the wall  7  and its periphery is in contact with the wall  6 . The gasket  14  is a tight fit around the portion  10   a  of the rod  10  so as to slide thereover in sealed manner. 
     The body  9  is generally in the form of a circularly symmetrical tube about the axis X. It is provided at one axial end with an annular rim  16  that projects radially outwards. The rim  16  is defined radially outwardly by a circularly cylindrical surface  17  about the axis X and situated in contact with the wall  6 . The end edge  18  of the body  9  adjacent to the rim  16  bears against the gasket  14  which it holds pressed against the wall  7 . The body  9  is retained in the housing  5  by crimping. More precisely, its section is narrowed at  19  where the wall  6  joins the remainder of the cap  2  so as to oppose radial displacement of the rim  16  in the housing  5  after the body  9  has been mounted in the cap  2 . 
     A disk  20  of elastomer material connects the body  9  to the rod  10 . The same face of this disk  20  is fixed both to the bottom end edge  21  of the body  9  remote from the rim  16  and to the bottom end edge  22  of the rod  10  remote from its end edge  12 . 
     FIG. 2 shows the disk  20  is isolation. The disk is axially symmetrical about an axis that coincides with the axis X in the example described. A central hole  23  passes through it on the axis. Four openings  24  that are uniformly spaced apart angularly around the axis X are provided through the thickness of the disk to cause the annular space  25  situated between the body  9  and the portion  10   b  of the rod  10  to communicate with the inside space of the receptacle that contains the substance. Each opening  24  occupies an angular sector occupying an angle at its apex on the axis X which is equal to about 50°, and is radially defined by two circularly arcuate edges centered on the axis X and interconnected by two generally rectilinear edges that are perpendicular thereto. The end edge  22  of the portion  10   b  of the rod  10  is fixed to the annular region  20   a  of the disk  20 , extending radially between the edges of the hole  23  and the radially inner circular arcuate edges of the openings  24 . The end edge  21  of the body  9  is fixed in the annular region  20   b  of the disk  20 , extending radially between the periphery  26  thereof and the radially outer circularly arcuate edges of the openings  24 . The actuator rod  10  and the valve body  9  are thus inter-connected by four bridges of material  27  that extend radially over the disk  20  between the openings  24 . The valve body  9 , the actuator rod  10 , and the disk  20  thus form a single part which is made by a dual-injection plastics molding technique. 
     It will be observed that the shapes of the valve body, of the actuator rod  10 , and of the disk  20  are relatively simple, thereby facilitating manufacture of the tooling used for making the valve. 
     More precisely, the body  9  and the rod  10  are made initially in the cavity of a mold having a sliding core by injecting a first plastics material that is relatively rigid. Thereafter, the core of the mold is moved and a second plastics or elastomer material is injected into the gap left by moving the core, thereby forming the disk  20 . A plastics or elastomer material is selected that is compatible with the first plastics material so that the disk  20  is assembled to the body  9  and to the rod  10  by local melting during injection. In the example described, the body  9  and the rod  10  are made of polypropylene and the disk  20  is made of an elastomer material known under the name “santoprene”. 
     The body  9 , the rod  10 , and the disk  20  are molded in the disposition shown in FIG. 3, with the end edge  22  of the rod  10  being slightly set back from the end edge  21  of the body  9 . The disk  20  is generally curved in shape with its concave face directed away from the actuator rod  10 . The face  28  of the disk  20  that is in contact with the body  9  and the actuator rod  10  is thus conical and parallel to its opposite face  29 . The plane containing the peripheral edge  30  of the face  29  and the plane containing the edge  31  of the hole  23  situated in the face  29  are offset through a distance d along the axis X. When the valve body  9  is assembled in the housing  5 , the rod  10  moves down through said distance d towards the inside of the receptacle and the disk  20  deforms elastically. It is thus pre-stressed and holds the shoulder  15  pressed against the gasket  14  to seal the receptacle hermetically. 
     The valve  1  operates as follows. The packaging and dispensing device is used with the cap  2  at the bottom, i.e. in a position which is upside-down relative to the position shown in FIG.  1 . At rest, the actuator rod  10  is urged by the disk  20  into the closed position, with the shoulder  15  coming into axial abutment against the gasket  14  as explained above. The orifice  11   b  then opens out into the thickness of the gasket  14  and is therefore closed thereby. In this position of the rod  10 , the faces  28  and  29  of the disk  20  extend generally perpendicularly to the longitudinal axis X. 
     When the user presses on the actuator rod  10  (indirectly via a pushbutton that forms a nozzle and that is mounted in conventional manner on the portion  10   a  of the rod, and that is not shown), the orifice  11   b  opens out into the space  25  inside the receptacle and enables the substance to flow out as expelled from the receptacle by the pressure of a propellant gas. The disk  20  is deformed elastically during this action of the user. When the user releases the pushbutton, the disk  20  returns to its initial shape, thereby returning the actuator rod  10  to its rest position which corresponds to the orifice  11   b  being closed by the gasket  14 . The resilient return force exerted by the disk  20  is proportional to the displacement of the disk  10  towards the inside of the receptacle. 
     Naturally, various modifications can be applied to the valve described above without going beyond the ambit of the invention, in particular, the valve body  9  may be associated with a dip tube enabling the device to be used with the cap  2  on top. In a variant, an additional gas inlet can be provided in the valve body  9  so as to dispense the substance (hair spray, deodorant, . . . ) in the form of a fine spray.