US3615042A

US3615042A - Plug valve assembly for fluid product dispenser having a stem configuration for easy manipulation and good sealing

Info

Publication number: US3615042A
Application number: US778905*A
Authority: US
Inventors: Jean Marand
Original assignee: Geigy Chemical Corp
Current assignee: Novartis Corp
Priority date: 1968-10-15
Filing date: 1968-10-15
Publication date: 1971-10-26
Anticipated expiration: 1988-10-26

Abstract

A VALVE STEM CONFIGURATION ADAPTED TO PROVIDE EASY MANIPULATION AND GOOD SEALING FOR INCORPORATION IN A PLUG VALVE ASSEMBLY FOR DISPENSERS OF FLUID PRODUCTS ADAPTED TO BE ATTACHED TO A PRODUCT CONTAINER FOR CONTAINING THE FLUID PRODUCT TO BE DISPENSED. THE PRODUCT CONTAINER ACCOMMODATES A PROPELLANT CARTRIDGE WITHIN THE PRODUCT CONTAINER. THE VALVE STEM IS HOLLOW AND HAS A PUSHBUTTON ACTUATOR ON THE UPPER END THEREOF WHICH HAS A NOZZLE THEREIN COMMUNICATING WITH SAID HOLLOW STEM. A CAP MEMBER FITS OVER A PRODUCT CONTAINER AND HAS AN APERTURE THEREIN THROUGH WHICH THE HOLLOW STEM IS MOVABLE, AND A SUPPORT IS SECURED TO THE UNDER SIDE OF SAID CAP AND HAS A HOLLOW CENTRAL PORTION THROUGH WHICH SAID HOLLOW STEM IS MOVABLE. A DIP TUBE IS SECURED IN SAID SUPPORT AND OPENS TO SAID HOLLOW INTERIOR, AND A FLUID PRODUCT FLOW PATH EXTENDS ALONG SAID HOLLW STEM EXTERIORLY OF THE HOLLOW THEREOF FROM A POINT ADJACENT SAID HOLLOW INTERIOR. A FIRST FLEXIBLE GASKET MEANS IS POSITIONED IN SAID PLUG VALVE ASSEMBLY THROUGH WHICH SAID HOLLOW STEM PASSES FOR OBTURATING SAID FLUID PRODUCT FLOW PATH BETWEEN SAID FLUID PRODUCT FLOW PATH AND SAID HOLLOW INTERIOR. THE SUPPORT HAS A DOWNWARDLY OPEN RECESS THEREIN, AND A SECOND FLEXIBLE GASKET MEANS IS POSITIONED IN THE BOTTOM OF SAID RECESS THROUGH WHICH SAID HOLLOW STEM PASSES. THE LOWER END OF THE HOLLOW STEM HAS A REDUCED DIAMETER NECK AND AT LEAST ONE APERTURE THEREIN OPENING INTO THE SPACE AROUND THE NECK, SAID APERTURE BEING OBTURATED BY SAID SECOND FLEXIBLE GASKET MEANS. A RETAINING RING HOLDS SAID SECOND GASKET MEANS IN SAID RECESS AND SECURED TO SAID SUPPORT AND HAS THE OUTER LOWER EDGE SECURED IN GAS TIGHT RELATIONSHIP TO A PROPELLANT CARTRIDGE.

Description

26, 1971 MARAND PLUG VALVE ASSEMBLY FOR FLUID PRODUCT DISPENSER HAVTNG 'A STEM CONFIGURATION FOR EASY MANIPULATION AND GOOD SEALING Filed Oct. 15, 1968 3 Sheets-Sheet 1 INVENTOR JEAN MARAND ATTORNEYS DEL 2 5, I971 A 3,615,042

PLUG VALVE ASSEMBLY FOR FLUID PRODUCT DISPENSER HAVING A STEM CONFIGURATION FOR EASY MANIPULATION AND GOOD SEALING Filed Oct. 15, 1968 3 Sheets-Sheet 2 5 7 22 32 28 4 23 la I INVENTOR JEA N MARAN D ATTORNEYS OOOOOOOOOOOOOOOOOOOOO A I Fi l e d O G t l 5 l 9 68 J. MAR RRRRR D P AND 3,615,042 RODUCT DISPENSER HAVING A STEM I IO3b .7?) BY g/mm i awg, ATTORNEYS United States Patent Otfice 3,615,642 Patented Oct. 26, 1971 3,615,042 PLUG VALVE ASSEMBLY FOR FLUID PRODUCT DISPENSER HAVING A STEM CONFIGURA- TION FOR EASY MANIPULATION AND GOOD SEALING Jean Mal-and, St. Benoit, France, assignor to Geigy Chemical Corporation, Ardsley, NY. Continuation-impart of application Ser. No. 718,165, Apr. 2, 1968. This application Oct. 15, B68, Ser.

Int. Cl. D6511 6/14 US. Cl. 222-193 28 Claims ABSTRACT OF THE DISCLOSURE A valve stem configuration adapted to provide easy manipulation and good sealing for incorporation in a plug valve assembly for dispensers of fluid products adapted to be attached to a product container for containing the fluid product to be dispensed. The product container accommodates a propellant cartridge within the product container. The valve stem is hollow and has a pushbutton actuator on the upper end thereof which has a nozzle therein communicating with said hollow stem. A cap member fits over a product container and has an aperture therein through which the hollow stem is movable, and a support is secured to the under side of said cap and has a hollow central portion through which said hollow stem is movable. A dip tube is secured in said support and opens into said hollow interior, and a fluid product flow path extends along said hollow stem exteriorly of the hollow thereof from a point adjacent said hollow interior. A first flexible gasket means is positioned in said plug valve assembly through which said hollow stem passes for obturating said fluid product flow path between said fluid product flow path and said hollow interior. The support has a downwardly open recess therein, and a second flexible gasket means is positioned in the bottom of said recess through which said hollow stem passes. The lower end of the hollow stem has a reduced diameter neck and at least one aperture therein opening into the space around the neck, said aperture being obturated by said second flexible gasket means. A retaining ring holds said second gasket means in said recess and secured to said support and has the outer lower edge secured in gas tight relationship to a propellant cartridge.

This application is a continuation-in-part of application Ser. No. 718,165, filed Apr. 2, 1968, now abandoned. This application relates to a plug valve assembly for dispensers of fluid products in which a high pressure gasket means in the bottom of the plug valve assembly is held in position by a retaining ring, the gasket engaging in a neck portion on the lower end of the stem to obturate at least one aperture opening into the neck from the interior of the stem, which gasket is deformed downwardly when the stem is depressed by pressure on the pushbutton on the upper end thereof and opens said aperture, and which, when the pressure on the pushbutton is released, urges the stern upwardly toward the obturating position.

There is already known in the art a pushbutton dispenser for dispensing a fluent product constituting an active agent in fractional amounts and in a spray, by means of a propellant gas under pressure held in a propellant cartridge placed inside the product container which contains said fluent product and which is carried on said support, which support is integral with a cover which seals off the aforementioned product container. This integral support and cover contains a high pressure obturating means for the propellant cartridge and a low pressure obturating means controlling, respectively, the passage of the product from the container to the pushbutton spray nozzle and the passage of air from the outside to the inside of the product container. A stern which conducts the propellant and the product in the direction of the spray nozzle is slidably mounted in said support and controls the aforementioned obturating means. This dispenser has the high pressure obturator mounted in the bottom of the support which is held therein by a substantially rigid retaming ring.

The high pressure obturator is positioned in a recess in the support which opens toward the propellant cartridge, said obturator being held in said recess by means of the retaining ring member which also forms part of the closure for said propellant cartridge. The retaining ring member consists of a separate annular part which is forced into a recess in the support and has a downwardly and outwardly extending portion positioned between the support and the collar of the propellant cartridge. The high pressure obturator is a thick gasket fitted sufficiently tightly around the stem so that when the lateral passage in the stem is within the gasket, the engagement is sufliciently tight to prevent passage of propellant between the stem and the gasket, and thus through the hollow stern through the lateral passages.

In practice, it has been found that this gasket must engage the stem so tightly that it is unnecessarily ditficult to depress the stem. Moreover, since the gasket is the only place where there is any contact between the stem and the support, it must act as a bearing as well as a gasket, and because it must be sufliciently resilient to seal around the stem, it permits the stem to tilt laterally in an objectionable fashion. This is undesirable in an apparatus of this type.

It is an object of the present invention to provide a stern and support which overcomes these drawbacks and permits easy operation of the stem, yet at the same time provides a good sealing effect and enables a portion of the stem to be in bearing contact with the support body.

To this end, there is provided a gasket for the high pressure obturator, which is relatively thin as compared to the gasket of the above described prior embodiment, and the stem has a neck portion therein into which the inner edge of the gasket is engaged for sealing the apertures opening into the space within the neck. The gasket is held in engagement with the neck portion in such a way that it urges the stem upwardly, yet it flexes easily when the stem is depressed so that the inner edge moves away from the neck portion and the apertures will open to permit passage of propellant into the stem. On release of the stem, the gasket will urge the stem upwardly. The body portion is provided with a bore opening out of the bottom of the cup therein, which fits closely around the stem above the neck portion and is in sliding bearing engagement with the stem. This acts as a bearing to hold the stem in line during its movement.

Other objects of the present invention will be brought out in the following description and accompanying drawings in which:

FIG. 1 is an axial sectional view of the upper part of one embodiment of the dispenser according to the present invention;

FIG. 2 is a sectional view taken along line 22 of FIG. 1;

FIG. 3 is a sectional view taken along line 3-3 of FIG. 1;

FIG. 4 is an enlarged fragmentary sectional view of the lower end of the stem and the surrounding parts of the embodiment of FIG. 1;

FIG. 5 is a view similar to FIG. 1 showing the parts in the dispensing positions;

FIG. 6 is an enlarged fragmentary sectional view similar to FIG. 4 showing a modification of the stem according to the invention;

FIG. 7 is a sectional view taken on line 77 of FIG. 6;

FIG. 8 is an enlarged fragmentary sectional view similar to FIG. 4 showing another modification of the stem according to the invention; and

FIG. 9 is an enlarged fragmentary sectional view similar to FIG. 4 showing still another modification of the stem according to the invention.

Referring to FIGS. 1 and 2 of the attached drawings, the dispenser comprises a product container C which is adapted to hold a flowable product such as a liquid or a finely divided powder. The product container is closed by a cover 1 from which depends the plug valve assembly. A propellant cartridge 43 depends from the plug valve assembly into the interior of the container C. The cover 1 is made, for example, of plastic material, to which support 2 is attached, these parts mutually abutting each other at a joint 33 where they fit together and hold therebetween a flexible annular low pressure sealing gasket 4 which is the low pressure obturator for the active agent and the low pressure obturator for the admission of air to the product container C from the outside. Parts 1 and 2 are attached to each other along the interfitting joint 33, and in the embodiment shown, the cover 1 has a depending flange 1a closely surrounded by an upwardly projecting flange 2a on the top of body 2, the depending flange 1a abutting a seat 26 on the top of the body 2. The joint is connected by ultrasonic welding.

Cover 1 has a central opening 5 and support 2 has an axial valve cup 6 therein, which opening and valve cup are traversed during the axial stroke of valve stem 7 connected to a valve actuator in the form of a pushbuttom 8 containing a nozzle insert 9 having a venturi type spray nozzle therein. Nozzle insert 9 is set into cavity 11 in the head of pushbutton 8. A bore 12 is provided in the bottom of body 2 between valve cup 6 and a diverging recess 13 in the base of support 2.

A flange 24 on valve stem 7 is urged upwardly by a spring 25 around valve stem 7, and is positioned between flange 24 and the bottom of cup 6. This spring acts to press the flange 24 upwardly so that the flexible lip of gasket 4 is held between a truncated cone-shaped seat 26 on flange 24, cambered as shown in FIG. 1, and an annular projection 28 around the edge of opening 5 in cover 1. This provides a tight closure of valve cup 6 with-- respect to opening 5 and a tight closure of passage 32 from the depending portion into the space beneath cover 1. In the raised position shown in FIG. 1, there is a space between the inner edge of gasket 28 and the tapered lower end of depending wall 22 on the pushbutton. This opens into the channels 21 described hereinafter.

Pushbutton 8, which caps valve stem 7, has two coaxial sockets at the base thereof: an outer socket 73, defined by depending wall 22 and which fits tightly around valve stem 7, and an inner socket 74 which receives the end 75 of stem 7. The extent to which sockets 73 and 74 can be forced along valve stem 7 is limited by an annular shoulder 76 at the base of fins 72 defining between them channels 21, along the outside of the stem 17. The channels open out of the stem through apertures 23.

The surface 78 of said flange 24 opposite gasket 4 is straight and serves as a support for spring 25, but this flange 24 also serves as a movable stop for the pushbutton assembly.

Into valve cup 6 opens the upper end of dip tube 29, force-fitted in a bore 31 in support 2, and which is for the passage of the active agent.

As shown more clearly in FIG. 4, the high pressure obturator is in the form of an annular flexible gasket 15 mounted in a downwardly opening recess 65 in support 2. The bore 12 from the valve cup 6 opens into recess 65, which in turn opens into recess 13.

Valve stem 7 is made in one piece, for example, by

4 molding, and has an axial bore 17 with the conical head 18 closing one end thereof. The valve stem 7 of the embodiment of FIGS. 1-5 has a lower cylindrical portion 7a which is slidable in bore 12 and is guided in its vertical movement in bore 12.

At the inner end of the stem 7 is a neck portion having a reduced diameter cylindrical portion 101 and a tapered portion 102 between the upper end of the cylindrical portion 101 and the cylindrical surface of the lower cylindrical portion 7a of the stem and tapered at an angle of about 30 to the vertical. The gasket portion further has a stepped portion having at least two steps 103 between the cylindrical portion 101 and the head 18. The outside diameter of the head 18 is no greater than the diameter of the bore 12 in order to permit passage of the head through the bore 12 during assembly of the stem 7 of the body portion 2.

The bore 17 within the stem 7 is tapered near the lower end thereof at 104, and terminates above the cylindrical portion 101. A plurality of downwardly extending passages 105 extend from the bottom of the bore 17 to the surface of the cylindrical portion 101 and open laterally from said surface. Because they extend straight down, they leave indentations 106 in the tapered inner surface of the bore 17.

The thickness of gasket 15 and the inside diameter thereof are such that in the raised position of stem 7 the inner edge of the gasket 15 is pressed against the cylindrical portion 101, the upper edge is deformed against the tapered portion 102, and the lower surface is deformed into tight engagement with step 103, thereby providing a tight seal of the ends of the passages 105.

Gasket 15 is held in recess 65 by a retaining ring 66. The latter is an independent member of a flexible, deformable and at least slightly resilient material, preferably metal, such as aluminum, somewhat in the shape of a truncated cone as shown in FIG. 5. The wall of the ring is deformed by being bent concavely. The retaining ring has a central aperture 67 through which the cone-shaped head 18 of valve stem 7 extends. The inner end of recess 65 is flared downwardly and outwardly, and the upper edge of the retaining ring 66 has the outer edge beveled where it bears on gasket 15 and acts to give the gasket a generally upward and inward position in the raised position of the valve stem. This gives an upward bias to the valve stem.

A cylindrical cavity 70 is defined at the lower end of support 2 by an annular flange 68. The lower end of retaining ring 66 is curved upwardly and outwardly to a flange 71 seated against the lower edge of annular flange 68. A sealing gasket (not shown) is held between the flange 71 and collar 69 of propellant cartridge 43. The terminal portion of the propellant cartridge is bent so as to fit closely to the contour of annular flange 68 and flange 71, forming a tight joint at the top of the propellant cartridge 43. The retaining ring 66 is made of a material which, in addition to being flexible, de-

formable and slightly resilient, is also impermeable with respect to the propellant contained in propellant cartridge 43. This prevents leaks as a result of permeability through the material of support 2.

With the parts assembled and the product container C and cartridge 43 filled, when valve stem 7 is in the undepressed position, as shown in FIG. 1, a tight closure is insured between valve stem bore 17 and the cartridge 43 by gasket 15, as described above, and between opening 5 which communicates with the outside atmosphere as a result of a clearance provided for the sliding movement of the valve stem and the space under the cover 1, which is in communication with the upper surface of gasket 4 through at least one radial channel 32 in the lower face of the downwardly depending portion from cover 1.

A second embodiment of the neck portion of the stem 7 is shown in FIGS. 6 and 7. The neck portion has the reduced diameter cylindrical portion 101a, the tapered portion 102a, and the stepped portion 103a substantially the same as in the embodiment of FIGS. 15. The passages 105a, however, open out of the bottom end of the stern bore 17, and extend straight down and open out of the tapered portion =102a adjacent the cylindrical portion 101a. In this instance, the gasket 15a should be thick enough to extend upwardly along the tapered portion 102a far enough to close the apertures at the ends of the passages 105a.

When the valve stem 7 is depressed to the position shown in FIG. 5, the low pressure obturator, which is gasket 28, is deformed downwardly, being bent away from the downwardly depending portion of the cover. This first opens the passage 32 to the atmosphere through the cover opening 5, and then the inner edge is bent away from the apertures 23 at the lower ends of the channels 21 while bearing tightly against the tapered lower end of depending Wall 22. Thus, the product flow path from the dip tube 29 through the cup 6 to the channels 21 and the nozzle in the nozzle insert 9 is opened. The high pressure obturator in the form of gasket 15 is likewise deformed and bent downwardly, the inner edge moving away from the apertures at the ends of passages 105, thus opening the propellant flow path from the cartridge 43 into the stem portion 17 to the nozzle in the nozzle insert 9. It is preferred that the dimensions of the apparatus be made such that the opening of the apertures at the ends of passages 105 take place after opening of the apertures 23 to the product flow path.

During this movement, the stem is guided by the sliding bearing engagement of the cylindrical portion 7a in the bore 12 in the body portion 2 so that lateral tilting of the stem is substantially prevented.

On release of the pushbutton, the spring 25 and the

gaskets

15 and 28 together urge the stem 27 upwardly to the initial position shown in FIG. 1, the closing of the various apertures taking place in the reverse order, i.e. the apertures at the ends of passages 105 closing first, then apertures 23 being closed by gasket 28, and the passage 32. At the uppermost position of the stem, apertures 23 are open to the atmosphere through the space between the inner edge of gasket 28 and the tapered layer end of wall 22. This enables the propellant still expanding in the propellant flow path to purge any product left in channels 21.

The gasket 15 should have a thickness more than the vertical dimension of the cylindrical portion 101 of the stem 7 so that it will be deformed upwardly against the tapered portion 102 and firmly deformed into the steps 103 in order to provide a tight seal. The upward inclination of the gasket 15 in the closed position of the apertures insures that a toggle type action is produced during the movement of the stem. As the stem moves downwardly, the material of the gasket 15 is comp'ressed'and deformed even further than in the position shown in FIG. 4, until the neck portion moves past the level of the gasket 15. At this point there will be a small downward force as the gasket material expands. In addition, the compression of the gasket material as the neck portion moves past the level position insures tight closing of the propellant flow path until after the apertures 23 in the product flow path have been opened. This is desirable in order to have the fluent product available as soon as the flow of propellant starts. I

The steps 103, when the taper angle of tapered

surface

102 or 102a is 30 or less to the vertical, penetrates the gasket material in order to provide a tight seal in the raised position of the stem. They also insure that the compression on the gasket material of the gasket 15 is released in stages, and the passages 105 are not opened until the last step moves away from the gasket material. This insures that the gasket will not crack away from the stem during the initial movement and allow leakage of the propellant.

It should be pointed out that the gasket 15 can be formed so that it will produce sufficient resilient force so that the spring 25 can be omitted if desired.

A third embodiment of the neck portion of the stem 7 is shown in FIG. 8. -It is the same as that of FIGS. 6 and 7 in that the neck portion has the reduced diameter cylindrical portion 101a, the tapered portion 102a, and the stepped portion 103a the same as in the embodiment of FIG. 8. The passages 105a, however, open out of the bottom end of the stem bore 17, and extend straight down and open out of the tapered portion 102a at a point spaced along the tapered surface 102a a distance v106 from the cylindrical portion 101a.

It has been found that it can be advantageous to use a somewhat thinner flexible gasket than that shown in FIGS. l-8, such a gasket flexing easier during Valve actuation. However, when this is done, it is necessary to change the configuration of the valve stem slightly to that shown in FIG. 9. In FIG. 9, the parts are generally the same as in FIGS. 6-8, except that the angle of the tapered portion 1021) is between 30 and 70, preferably about 40, to the vertical. With this change, the steps can be eliminated, and an unstepped sloping surface 1031) can be used. Otherwise the construction is the same, the stern having the cylindrical portion 101b with the passages 1051) open ing out of the sloping surface 1102b at a point spaced a distance -106b from the cylindrical portion 101b.

Further, by using a thin gasket with a stem having a sloped area and 40 angle on the taper, the opening of the propellant will be delayed until after the liquid flow path is open. This sloped area actually functions in much the same manner as the previous steps. As actuation of the valve is comenced, the gasket 15b moves away from the point 107, but does not allow propellant out of the system. On continuing actuation, the gasket will finally move away from point 108 and release propellant. This release of propellant actually occurs after the gasket has bent in a reverse angle to that which it holds while the system is at rest. Further, with a 40 angle on the taper 1021) and the sloped area 103b, the gasket imbeds itself in the critical portion of the surface 103b more securely, thereby resulting in a tighter seal. This imbedding is assisted by the gasket sliding downward on a 40 angle of the taper 1102b and upward on the surface 10312 moving into the critical sealing portion of the stem.

In injection molding, the angle at point 109' is very difficult to fill with plastic material if the angle at point 110 is sharper than 40. If point 109 does not fill out properly, the configuration of the propellant holes 10511 will be irregular. With a 40 angle on the taper 10% of the stem, angle 109 is sufiiciently large to easily fill out with plastic material during molding, thereby resulting in more uniformly shaped propellant holes.

If the angle of the tapered portion 1021) of the stem is too great (for example over 70), the gasket will have ditficulty finding the slotted portion during assembly. At 40 assembly is achieved easily and the gasket moves into the slotted portion positively. The inner diaphragm will move into the slotted portion easier with a stem having the sloped surface 1031: rather than the steps.

A further advantage of using sloped surface .1031) is that the propellant filling is made easier because of the aerodynamic curve the propellant follows. With the steps, the propellant has a tendency to bank or deflect off of the second step and move upwards before continuing on its eventual downward path. This reduces propellant filling efiiciency.

It is thought that the invention and its advantages will be understood from the foregoing description and it is apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing its material advantages, the forms hereinbefore described and illustrated in the drawings being merely preferred embodiments thereof.

What is claimed is:

1. A plug valve assembly for dispensers of fluid products adapted to be attached to a product container for containing the fluid product to be dispensed and adapted to accommodate a propellant cartridge within the product container, said plug valve assembly comprising a hollow valve stem, a pushbutton actuator on the upper end of said stem and having a nozzle therein communicating with said hollow stem, a cap member adapted to fit over a product container and having an aperture therein through which the hollow stem is movable, a support secured to the under side of said cap and having a hollow interior through which said hollow stem is movable, a dip tube secured in said support and opening into said hollow interior, means forming a fluid product flow path along said hollow stern exteriorly of the hollow thereof from a point adjacent said hollow interior, a first flexible gasket means in said assembly through which said hollowstern passes obturating said fluid product flow path between said fluid product flow path and said hollow interior, said support having a downwardly open recess therein, a second flexible gasket means in the bottom of said recess through which said hollow stem passes, retaining ring means retaining said second flexible gasket in the bottom of said recess and adapted to be connected to the propellant cartridge, said stem having a lower cylindrical portion and said support having a bore therethrough between said hollow interior and said downwardly open recess in which said cylindrical portion is in sliding bearing engagement, said stem further having a neck portion in the lower end of said cylindrical portion, which neck portion has a reduced diameter cylindrical portion, a tapered portion joining the upper end of said reduced diameter cylindrical portion to said stem cylindrical portion and a downwardly and outwardly inclined portion joining the lower end of said reduced diameter cylindrical portion to the bottom of said stern, said stem having downwardly extending passages therein from the hollow of said stem to said neck portion and opening out of said neck portion, and said second flexible gasket having a thickness greater than the vertical dimension of said reduced diameter portion and being deformed into engagement with said tapered portion and said downwardly and outwardly inclined portion in the raised position of said stem to seal off said passages in the stem.

2. A plug valve assembly as claimed in claim 1 in which said downwardly extending passages extend along the surface of said reduced diameter cylindrical portion and open laterally of said reduced diameter cylindrical portion.

3. A plug valve assembly as claimed in claim '1 in which said downwardly extending passages extend to said tapered portion and open out of said tapered portion.

4. A plug valve assembly as claimed in claim 3 in which said passages open out of said tapered portion adjacent said reduced diameter cylindrical portion.

5. A plug valve assembly as claimed in claim 3 in which said passages open out of said tapered portion at a point spaced from said reduced diameter cylindrical portion.

6. A plug valve assembly as claimed in claim 1 in which said downwardly and outwardly inclined portion is stepped.

7. A plug valve assembly as claimed in claim 1 in which said downwardly and outwardly inclined portion is smooth.

8. A plug valve assembly as claimed in claim 1 in which said downwardly and outwardly inclined portion is smooth and said tapered portion is tapered at an angle of from 30 to 70 to the vertical.

9. A plug valve assembly as claimed in claim 8 in which said tapered portion is tapered at an angle of about 40.

10. A plug valve assembly as claimed in claim 1 in which said recess is flared downwardly and outwardly and the end of said retaining ring engaged with said second flexible gasket is beveled inwardly and upwardly, said second flexible gasket extending inwardly and upwardly into engagement with said neck portion when the stem is in the raised position, whereby the material of said gasket is compressed further as the neck portion moves past the gasket as the stem is being depressed to improve the sealing action and delay opening of the passages.

11. A plug valve assembly for dispensers of fluid products adapted to be attached to a product container for containing the fluid product to be dispensed and adapted to accommodate a propellant cartridge within the product container, said plug valve assembly comprising a hollow valve stem, a pushbutton actuator on the upper end of said stem and having a nozzle therein communicating with said hollow stem, a cap member adapted to fit over a product container and having an aperture therein through which the hollow stem is movable, a support secured to the under side of said cap and having a hollow interior through which said hollow stem is movable, a dip tube secured in said support and opening into said hollow interior, means forming a fluid product flow path along said hollow stem exteriorly of the hollow thereof from a point adjacent said hollow interior, a first flexible gasket means in said assembly through which said hollow stem passes obturating said fluid product flow path between said fluid product flow path and said hollow interior, said support having a downwardly open recess therein, a second flexible gasket means in the bottom of said recess through which said hollow stem passes, retaining ring means retaining said second flexible gasket in the bottom of said recess and adapted to be connected to the propellant cartridge, said stem having a stern cylindrical portion at the lower end thereof with a neck portion in the lower end of said stem cylindrical portion, which neck portion has a reduced diameter cylindrical portion, a tapered portion joining the upper end of said reduced diameter cylindrical portion to said stem cylindrical portion and a downwardly and outwardly inclined portion joining the lower end of said reduced diameter cylindrical portion to the bottom of said stem, said stem having downwardly extending passages therein from the hollow of said stem to said neck portion and opening out of said neck portion, and said second flexible gasket having a thickness greater than the vertical dimension of said reduced diameter portion and being deformed into engagement with said tapered portion and said downwardly and outwardly inclined portion in the raised position of said stem to seal olf said passages in the stem.

12. A plug valve assembly as claimed in claim 11 in which said downwardly extending passages extend along the surface of said reduced diameter cylindrical portion and open laterally of said reduced diameter cylindrical portion.

13. A plug valve assembly as claimed in claim 11 in which said downwardly extending passages extend to said tapered portion and open out of said tapered portion.

14. A plug valve assembly as claimed in claim 13 in which said passages open out of said tapered portion adjacent said reduced diameter cylindrical portion.

15. A plug valve assembly as claimed in claim 13 in which said passages open out of said tapered portion at a point spaced from said reduced diameter cylindrical portion.

16. A plug valve assembly as claimed in claim '11 in which said downwardly and outwardly inclined portion is stepped.

17. A plug valve assembly as claimed in claim 11 in which said downwardly and outwardly inclined portion is smooth.

18. A plug valve assembly as claimed in claim 11 in which said downwardly and outwardly inclined portion is 9 smooth, and said tapered portion is tapered at an angle of from 30 to 70 to the vertical.

19. A plug valve assembly as claimed in claim 18 in which said tapered portion is tapered at an angle of about 40.

20. A plug valve assembly as calirned in claim 11 in which said recess is flared downwardly and outwardly and the end of said retaining ring engaged with said second flexible gasket is beveled inwardly and upwardly, said second flexible gasket extending inwardly and upwardly into engagement with said neck portion when the stem is in the raised position, whereby the material of said gasket is compressed further as the neck portion moves past the gasket as the stem is being depressed to improve the sealing action and delay opening of the passages.

21. A hollow stem for forming part of a valve means for an aerosol dispenser, said stern having a lower cylindrical portion, said stem further having a neck portion in the lower end of said cylindrical portion, which neck portion has a reduced diameter cylindrical portion, a tapered portion joining the upper end of said reduced diameter cylindrical portion to said stern cylindrical portion and a downwardly and outwardly inclined portion joining the lower end of said reduced diameter cylindrical portion to the bottom of said stem, said stem having means forming downwardly extending passages therein generally parallel to the stem axis from the hollow of said stem to said tapered portion and opening out of said tapered portion, said neck portion being adapted to cooperate with a flexible gasket in the valve means which gasket has a thickness sufficiently great to extend from said inclined portion to said tapered portion above the openings of said downwardly extending passages and which is deformed into engagement with said tapered portion and said downwardly and outwardly inclined portion in the raised position of said stem to seal off said passages in the stem.

22. A hollow stem as claimed in claim 21. in which said passages open out of said tapered portion adjacent said reduced diameter cylindrical portion.

23. A hollow stem as claimed in claim 21 in which said passages open out of said tapered portion at a point spaced from said reduced diameter cylindrical portion.

24. A hollow stern as claimed in claim 21 in which said downwardly and outwardly inclined portion is stepped.

25. A hollow stem as claimed in claim 21 in which said downwardly and outwardly inclined portion is smooth.

26. A hollow stem as claimed in claim 21 in which said downwardly and outwardly inclined portion is smooth and said tapered portion is tapered at an angle of from 30 to to the vertical.

27. A hollow stem as claimed in claim 26 in which said tapered portion is tapered at an angle of about 40.

28. In combination, a hollow stem for forming part of a valve means for an aerosol dispenser, said stem having a lower cylindrical portion, said stern further having a neck portion in the lower end of said cylindrical portion, which neck portion has a reduced diameter cylindrical portion, a tapered portion joining the upper end of said reduced diameter cylindrical portion to said stem cylindrical portion and a downwardly and outwardly inclined portion joining the lower end of said reduced diameter cylindrical portion to the bottom of said stem, said stem having downwardly extending passages therein from the hollow of said stem to said tapered portion and opening our of said tapered portion, and a flexible gasket having a thickness sufiiciently great to extend from said inclined portion to said tapered portion above the openings of said downwardly extending passages and being deformed into engagement with said tapered portion and said downwardly and outwardly inclined portion in the raised position of said stem to seal off said passages in the stern.

References Cited UNITED STATES PATENTS 2,818,202 12/ 1957 Abplanalp 222-40224 2,968,428 1/1961 Samuel 222-402.24 X 3,261,557 7/1966 Greenbaum 222402.24 3,289,949 12/1966 Roth 239-406 X 3,332,626 7/1967 Meshberg 222402.24 X

ROBERT B. REEVES, Primary Examiner F. R. HANDR-EN, Assistant Examiner US. Cl. X.R. 222399, 402,24