Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D83/00—Containers or packages with special means for dispensing contents
  • B65D83/14—Containers for dispensing liquid or semi-liquid contents by internal gaseous pressure, i.e. aerosol containers comprising propellant
  • B65D83/44—Valves specially adapted for the discharge of contents; Regulating devices
  • B65D83/52—Metering valves; Metering devices
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
  • F16K25/00—Details relating to contact between valve members and seats
  • F16K25/005—Particular materials for seats or closure elements

Definitions

• the present invention relates to a valve. improved and more particularly a metering valve valve stem.
• Valves are well known in the art. They find their main application with aerosol containers for the distribution of liquid products loaded with a propellant (gas dissolved under pressure).
• the valves When metered, the valves generally comprise a valve body enclosing a metering chamber delimited axially by two annular seals, a valve seal and a chamber seal, and a valve stem movable between a rest position and a position actuation.
• This valve stem is biased by a spring towards its rest position, in which a shoulder of said stem rests on the lower surface of said valve seal.
• the valve stem which slides in the valve body inside the annular seals is pressed up to its actuation position, in which a dose of the product is expelled.
• valve stems of the valves in particular of the metering valves, relate in particular to the sealing at the level of the valve seal.
• the valve stem must be able to slide between its actuation position and its rest position under the effect of the spring, while preventing leaks from occurring.
• valves have a cylindrical valve stem having an extension of said shoulder, at least on the portion of the valve stem which slides in the valve seal, a constant outside diameter approximately equal (in general very slightly greater ) to the outside diameter of the central opening of the valve seal.
• a frustoconical part adjacent to said shoulder which extends axially over part of the thickness of said valve seal.
• a disadvantage of this implementation lies in the fact that the friction which appears during the sliding of the valve stem can be relatively high, which can lead to a blockage of said valve stem.
• This phenomenon is further amplified when, in particular for ecological reasons, it is desired to replace the propellant gases harmful to the environment, such as than CFCs, by propellant gases which are not, or less harmful to the environment, such as for example HFA gases.
• propellant gases which are not, or less harmful to the environment such as for example HFA gases.
• the use of such gases which are little or not harmful implies a significant increase in the pressure inside the valve body, this increase being able to go up to 50%. It is therefore necessary to produce an even greater seal at the level of the valve seal, which implies significant friction between the valve stem and said seal.
• An object of the invention is to provide a valve, in particular a metering valve having a valve stem made in such a way as to avoid inadvertent blocking of the latter by friction on the valve seal, when said valve stem from its actuating position to its rest position under the action of the spring, while ensuring sealing at the level of said valve seal during this movement.
• Another object of the invention is to provide a valve, in particular a metering valve comprising a valve stem made so as to be able to operate reliably and safely with a spring of low stiffness, thus facilitating its actuation.
• Yet another object of the invention is therefore to provide a valve, in particular a metering valve operating with a propellant gas which is not harmful to the environment, said valve comprising a valve stem which can slide without leakage and without risk of blockage between its actuation position and its rest position under the effect of the spring.
• the invention therefore relates to a valve device intended to be mounted in the opening of the neck of a container containing product to be dispensed, comprising a valve body enclosing a chamber delimited axially on one side by a valve seal. annular, said seal having a central opening, and a valve stem passing through the seal and comprising a distribution channel opening through a radial hole on its outer surface, said valve stem being movable inside the valve body between a position rest where the radial hole opens out of the chamber, and an actuating position where the radial hole opens out inside the chamber, the valve stem being urged by an elastic member towards its rest position, characterized in that said valve stem is molded from a material comprising a mixture of an acetal resin, polytetrafluoroethylene (PTFE) and silicone, so that said valve stem slides with low friction on said valve seal.
• PTFE polytetrafluoroethylene
• valve stem of the invention therefore slides with less friction, which avoids the appearance of blockage of the valve stem.
• said material of the valve stem is made of acetal resin, PTFE and silicone.
• said acetal resin is polyoxymethylene.
• the material of the valve stem contains up to about 25% PTFE and up to about 10% silicone.
• the silicone is incorporated into the material of the valve stem in the form of silicone oil.
• the valve stem is further coated with an outer layer of silicone.
• the valve is a metering valve and the chamber is a metering chamber delimited axially, on the side opposite to the valve seal, by an annular chamber seal comprising a central opening traversed by the valve stem .
• the valve stem of the invention also makes it possible to limit friction at the level of the chamber seal.
• FIG. 1 is a schematic sectional view of a metering valve according to an embodiment of the present invention, the valve stem being in its rest position
• - Figure 2 is a view similar to that of Figure 1, the valve stem being in its actuation position .
• a metering valve according to the invention comprises a valve body 1 containing a metering chamber 2.
• This metering chamber 2 is delimited axially by two annular seals, a valve seal 3 and a gasket chamber 4. These two seals each have a central opening through which passes a valve stem 10, movable inside the valve body 1 between a rest position, shown in FIG. 1, and an actuation position, represented on the Figure 2.
• This valve stem 10 is biased towards its rest position by an elastic member such as a spring 5, bearing on the one hand on the bottom of the valve body 1 and on the other hand on the lower end valve stem.
• valve body 1 is crimped in a capsule 100 which is then fixed, for example by crimping, on the neck of any container or bottle (not shown).
• a neck seal 101 is provided between said capsule 100 and said neck of the container.
• the valve stem 10 comprises an upper element 10a extending outside the valve body 1, and a lower element 10b on which said spring acts.
• the upper element 10a of the valve stem comprises an axial channel 12 emerging through a radial hole 13 at its outer surface. In the rest position of the valve stem, said radial hole 13 opens outside the valve seal 3, while in said actuating position it opens inside the metering chamber 2.
• the upper element 10a of the valve stem further comprises a radial shoulder 1 1 which rests on the lower surface of the valve seal 3 in the rest position of the valve stem 10, and which therefore defines said rest position in acting as a stop member against the thrust of the spring 5.
• the lower element 10b of the valve stem also comprises an axial duct 14 and two radial ducts 15a and 15b, respectively lower and upper.
• these conduits 14, 15a and 15b connect a product reservoir with the metering chamber 2 allowing filling of the latter, while in the actuation position of the valve stem, no of the two radial conduits 15a and 15b does not open into the metering chamber 2.
• the operation of this metering valve is conventional.
• the user exerts pressure on the upper element 10a of the valve stem 10 which has the effect of moving the latter against the force of the spring 5 out of its rest position.
• the upper radial duct 15b no longer opens into the metering chamber 2 and the latter is then hermetically closed by said upper element 10a of the valve stem at the level of the chamber seal 4 and of the valve seal 3.
• the valve stem 10 reaches its actuation position, the radial hole 13 of the upper element 10a of the valve stem opens into the metering chamber 2, thus allowing the distribution of the dose of product contained in said metering chamber via the axial channel 12.
• the user then releases his pressure on the valve stem 10 which is returned by the spring 5 to its rest position where the radial duct upper 15b opens into the metering chamber 2, to fill the latter with a new dose of product.
• the invention provides for making the valve stem 10 from a material whose friction qualities are improved, that is to say that is, it slides better on the seals.
• the invention provides for making the valve stem 10 from a material comprising an acetal resin, polytetrafluoroethylene (PTFE) and silicone. More specifically, the acetal resin can be polyoxymethylene and the silicone can be present in the mixture in the form of silicone oil.
• a material consisting of polyoxymethylene, in a proportion of approximately 80% by weight, PTFE in a proportion of approximately 15% by weight and silicone oil in a proportion of approximately 5% by weight, is suitable for making the valve stem of the invention.
• PTFE in a proportion of approximately 15% by weight
• silicone oil in a proportion of approximately 5% by weight
• valve stem 10 sliding better on the seals, its external dimensions can therefore be provided so that it cooperates with the seals to ensure a perfect seal, even when using non-harmful gases such as HFA, while ensuring perfect sliding in the central opening of said seals, thus avoiding the problems of blocking of the rod.
• the stiffness of the spring 5 must be directly proportional to the friction forces exerted by the valve seal 3, the invention therefore allows the use of a spring having a lower stiffness.
• the actuation of the metering valve according to the invention is therefore facilitated in that the force necessary to actuate it is reduced.
• valve stem of the invention is that due to the reduction in the friction forces exerted by the valve seal 3 on the valve stem 10 when the latter returns to its rest position, the speed displacement of said valve stem is higher, which increases the reliability of the valve.
• the invention therefore guarantees reliable operation of the metering valve and complete tightness at the valve seal, which in particular allows the use of propellant gases which are not harmful to the environment, such as HFA gases, despite the increase significant pressure inside the metering chamber.
• the use of a spring of lower stiffness is made possible, which facilitates the actuation of the metering valve.
• the invention has been described with reference to the figures which represent a metering valve operating in an upright position, but it obviously also applies to metering valves operating in an inverted position.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Dispersion Chemistry (AREA)
• Containers And Packaging Bodies Having A Special Means To Remove Contents (AREA)
• Gasket Seals (AREA)
• Filling Or Discharging Of Gas Storage Vessels (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=9484090

Family Applications (1)

Country Status (6)

Cited By (7)

Families Citing this family (25)

Citations (3)

Family Cites Families (10)

• 1995
  • 1995-10-31 FR FR9512840A patent/FR2740527B1/fr not_active Expired - Fee Related
• 1996
  • 1996-10-24 JP JP51710697A patent/JP3680177B2/ja not_active Expired - Lifetime
  • 1996-10-24 WO PCT/FR1996/001663 patent/WO1997016360A1/fr not_active Ceased
  • 1996-10-24 EP EP96934964A patent/EP0858420B1/fr not_active Expired - Lifetime
  • 1996-10-24 US US09/051,967 patent/US6112950A/en not_active Expired - Lifetime
  • 1996-10-24 DE DE69603872T patent/DE69603872T2/de not_active Expired - Lifetime

Patent Citations (3)

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