US3472426A

US3472426A - Mixing and codispensing aerosol valve for hot shaving lather and other preparations

Info

Publication number: US3472426A
Application number: US751654A
Authority: US
Inventors: William Z Nesin
Original assignee: WILLIAM Z NESIN
Current assignee: WILLIAM Z NESIN
Priority date: 1968-07-03
Filing date: 1968-07-03
Publication date: 1969-10-14
Anticipated expiration: 1986-10-14

Description

0t.14.." `1 969 ZNESIN; 3,472,426

MIXING VAND.CODISPENSING AEROSOL VALVE FOR HOT l SHAVING LA'I'HER` AND OTHER `IRI-PARTIONS Filed July 5,-1968 2 Sheets-Sheet` l 1 mm 11| i Oct. 14, 1969 MIXING AND CODISPENSING AEROSOL VALVE FOR HOT SHAVING'LATHER AND OTHER PREPARATONS Filed July 3, 1968 W Z. NESIN 2 Sheets-Sheet lV 5% 560-1 a0 l 592 HHIIIIIVJI/ V ,L

5 592 su l 564 f 4 594 554 mvENTQR. 556 550-1 W han Z. /Ves'uc BY JLM M United States Patent O 3,472,426 MIXING AND CODISPENSENG AEROSOL VALVE FOR HOT SHAVING LATI-IER AND OTHER PREPARATIONS William Z. Nesin, New York, N.Y. (445 West 240th St., Bronx, N. Y. 10463) Filed July 3, 1968, Ser. No. 751,654 Int. Cl. B67d 5/62 U.S. Cl. 222-146 22 Claims ABSTRACT OF THE DISCLOSURE This is a valve of the type which codispenses and mixes two materials packaged separately within the same aerosol can, for example a shaving cream concentrate and a hydrogen peroxide activant which react with each other when mixed to produce a warm shaving lather. The valve cornprises a housing in which there are a pair of coaxial washers. A stern is received within the central openings of the two washers and has an axial blind bore at one end. When the stem is displaced from a normal position relative to the two washers, a first valve allows the shaving cream concentrate to escape through a port in the side wall of the stem into the bore, and then to be dispensed. A second valve also responds to the actuation of the stem to allow the activant material to enter the bore at the same time, so that it is mixed with the shaving cream and dispensed therewith. In one embodiment of the invention the second valve includes a keyway of tapered width cut into the stem which is designed to maintain substantially the same proportion of shaving cream and hydrogen peroxide over a range of dispensing rates. rl`he keyway may also be tapered into the depth of the stem, or it may be replaced by a sequence of staggered keyways. In another embodiment the key-way is replaced entirely by an elongated port which protrudes a variable distance into the activant chamber when the stem is actuated. The foregoing embodiments all involve reciprocable stem valves, but there is also an embodiment which operates by lateral pressure on the valve stem.

FIELD OF THE INVENTION This invention relates to aerosol valves, and is particularly concerned with valves for use in codispensing a predetermined proportion of two different materials both under aerosol pressure, such as a shaving cream and an oxidizing material for raising the temperature of the shaving cream as it is dispensed.

THE PRIOR ART There is now on the market a new type of aerosol shaving cream package which delivers a warm shaving cream product even though the package and its contents are at room temperature. The heat necessary to raise the temperature of the shaving cream preparation is generated at the time the shaving cream is dispensed, by virtue of an exothermic chemical reaction between the shaving cream mixture and an activant, usually hydrogen peroxide or some other oxidizer. The activant is stored separately Within'the aerosol can, but is mixed and dispensed together with the shaving cream preparation to produce the exothermic reaction at the time that the shaving cream is used. This requires a special aerosol package with an inner reservoir for separate storage of the activant material, and

a special aerosol valve designed to mix and codispense the shaving cream concentrate and the activant material.

A number of prior art aerosol valves have been designed to perform this specialized function, but all have suffered from one or more disadvantages. For example, prior art aerosol valves of this type mix the concentrate and activant in one proportion when the shaving cream is dispensed slowly, and in a different proportion on those occasions when the materials are dispensed more rapidly. In other words, the proportion of activant and concentrate materials varies as a function of the dispensing rate. Consequently, the optimum proportion is not achieved under all conditions.

Another problem with prior art valves is that they have a tendency to allow small amounts of concentrate and activant to mix within the aerosol package instead of keeping them entirely separate until they are dispensed. In particular, some prior art mixing valve constructions have allowed the shaving cream concentrate to leak into the activant reservoir. The shaving cream concentrate contains a Freon propellant which is the source of pressure for dispensing the concentrate, and Freon usually contains a small amount of iron chloride impurity. Iron chloride, when it leaks into the activant: chamber, reacts with some of the hydrogen peroxide oxidizing agent and thus leaves a lesser amount of the peroxide material available for subsequently heating the shaving cream.

The leakage of the Freon material along with its iron chloride impurities into the hydrogen peroxide activant reservoir is particularly troublesome during the filling of the aerosol can, when the Freon propellant is injected into the can under high pressure. At that time, imperfect seals are particularly likely to allow the Freon material and its impurities to contaminate the activant.

Still another disadvantage of prior art valves arises from the fact, that at the time of dispensation, the hydrogen peroxide material and the shaving cream concentrate are mixed at the mouth of the opening through which the shaving cream concentrate escapes into the dispensing conduits. The pressurized flow of shaving cream concentrate through these orices is relied on to sweep along with it most of the activant material mixed therewith, but some of the activant remains behind and finds its way into the concentrate chamber after dispensation, where it reacts with the concentrate inside the can and is therefore wasted.

SUMMARY AND OBJECTS OF THE INVENTION A principal object of this invention is to provide an aerosol mixing valve which achieves proportional dispensation, i.e. which dispenses substantially the same proportion of activant and concentrate materials over a range of dispensing rates, from slow to rapid dispensation. Another important objective is to provide a superior sealing construction in an aerosol valve of this type, which will solve some of the problems of leakage and contamination resulting from allowing the activant and concentrate materials to come together inside the aerosal can prior to or after dispensation.

The valve of this invention is an improvement upon the type of prior art aerosol mixing valve which has a valve housing and a stem vertically reciprocable within that housing to operate a pair of valves, one of which releases the concentrate material and the other of which releases the activant material. The first valve employs an annular seal which cooperates with a washer to close olf a port formed in the side wall of the stem leading to a central bore formed in the stem. The second valve comprises a keyway formed in the wall of the stem, and positioned to slide through a sleeve formed in the valve housing. The valve stem is reciprocated to actuate both valves simultaneously, and a coil spring surrounds the stem within the valve housing to return it to its normal position for reclosing the valves.

Like most prior art valves, the one just described suffers from an inability to maintain a constant proportionality between activant and concentrate over a range of dispensing rates, and in addition the lower valve formed by the keyway reciprocated within the sleeve does not provide an adequate seal to prevent internal contamination.

To this prior art structure, the present invention adds a second washer which surrounds and cooperates with the stem at the lower end thereof to form part of the second valve. This washer provides an improved seal, particularly in combination with the coil spring which now serves the additional function of biasing the second washer tightly against a sealing seat formed in the internal wall of the valve housing.

In one embodiment of the invention the keyway is tapered so as to mtaintain a constant proportionality as the stern is depressed to open the valve further and thereby achieve a more rapid dispensation rate, The keyway may be tapered either across its width or into the depth of the valve stem. In another embodiment there may be a plurality of staggered keyways which move into valving position in sequence so as to maintain proportionality. In still another embodiment the keyway may be replaced by an elongated port communicating with an extension of the central bore within the valve stem, and this elongated port protrudes a varied distance into the activant chamber to maintain proportionality. In still another embodiment of the invention the second washer is distorted to perform the valving operation in response to lateral displacement of the valve stem, and the dimensions of the valve may be so chosen that constant proportionality is maintained as a function of stem displacement.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. l is a side elevational view, with parts broken away and sectioned for clarity of illustration, of an inverted aerosol can containing separately packaged activant and concentrate materials, and having assembled therewith a proportional mixing and codispensing valve according to this invention. In this view, the valve is shown completely closed.

FIG. 2 is a sectional view of the same valve shown in a partially actuated position so that the material inside the can is dispensed slowly.

FIG. 3 is a similar sectional View showing the same valve in a fully actuated position so `as to dispense the material rapidly.

FIG. 4 is a sectional View taken along the lines 4-4 of FIG. 3 showing the stem and second washer assembly of this valve.

FIG. 5 is an elevational view of an alternative embodiment of a stem for use with the valve of this invention.

FIG. 6 is a sectional view of still another alternative embodiment of a stem for use with the valve of this invention FIG. 7 is an elevational view, with parts broken away and sectioned, of another valve embodiment in accordance with this invention.

FIG. 8 is an elevational view, with parts broken away and sectioned, of still another valve in accordance with this invention, and designed for lateral displacement of the valve stem, as distinguished from the axial displacement of the valve stem in the other embodiments illustrated.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The aerosol can 9 is of conventional construction, and includes a cylindrical metal outer wall 10 and a metal bottom member the edge of which is curled about the lower edge of the lwall 10 to form a bead 12 around the lower periphery of the can. In all the drawings, the aerosol can is shown upside down, since the valve employed is of the type which requires the can to be inverted for proper operation. However, it will be readily appreciated that the can may also be operated in the upright position simply by using a conventional dip tube. At the top of the can is a metal dome 14 the edge of 4 which is curled over the upper edge of the wall 10 to form a bead 16 around the upper periphery of the can. The dome 14 has a large central opening which is sealed ott by a metal valve support 18. The valve support edge is curled about the upper edge of the dome 14 to form still another bead 20 at the top of the can. The valve support 18 seals ott the top of the can in cooperation with a novel aerosol valve 2.?. with which it is assembled.

A flexible plastic bag 24 inside the aerosol can 9 contains the activant material 26, such as hydrogen peroxide or some other oxidizer, which produces the exothermic reaction for heating the shaving cream concentrate Z8 when the two are mixed and codispensed through the' valve 22. The concentrate 28, which includes the usual Freon propellant, is stored within the aerosol can 9 but outside the activant bag 24. Since the bag 24 is flexible and therefore collapsible under pressure, the Frcon gas pressure within the aerosol can 9 but outside the bag 24 serves to eject the activant material 26 from the bag 24 at the same time that it ejects the shaving cream concentrate 28 from the aerosol can 9.

The can construction, including the inner container 24 with the activant material 2% for reacting with the shaving cream concentrate 28, is entirely conventional. The present invention is concerned exclusively with an improved structure of the mixing and codispensing valve 22, which will now be described in detail.

The valve support 18 has a central boss 18-1 which isy formed by sheet metal stamping. Within the interior of the boss 13-1 is inserted a plastic molded valve housing 3f.) of generally cylindrical conliguration. At the interior end of the housing 3) is a disc 32 molded integrally therewith, and having an integrally molded depending ange 3d. The open end of the tlexible plastic activant bag 24 is sealed entirely about the flange 34, as by heat-sealing, so as to contain the activant material 26 within the bag. Thus the activant material 26 can escape from the bag only through a central cylindrical opening 36 formed in the valve housing 3u.

The valve support 18 is crimped at location 18-2 so as to hold the valve housing 3G securely in place and also to form a seal entirely about the valve housing 30 which prevents the shaving cream concentrate 2S under pressure from escaping between the valve support 18 and the Valve housing 30. The outside surface of the exterior end of the valve housing 3@ is formed with ribs 30-1, between which are channels 3tl-2 through which the Freon and shaving cream concentrate 28 are injected under very high pressure and forced past the crimp 18-2 when the aerosol can 9 is originally lled.

A first washer 38 formed of a Buna material closes ott the outer end of the cylindrical housing 30 to enclose a valve chamber 46. A flange 18-3 of the valve support is folded over the iirst washer 3S to hold the latter firmly in place against a seat Sil-9 formed in the housing 30. A central opening 11S-. remains in the valve support 18, into which the Freon and shaving cream concentrate are injected under great pressure so as to force its way between the ilange 18-3 and lirst washer 38 and thus reach the iilling channels 30-2 when the can 9 is loaded. The activant material 26 is initially loaded into the bag 24 by merely placing it inside the bag before sealing the bag to the flange 34.

A molded plastic valve actuator 49 sits on top of the aerosol can 9. This consists of a cylindrical skirt 50 integrally molded with a liange 52 which snap-tits over the bead 20 to secure the valveI actuator in place upon the aerosol can 9. A discharge pipe 54 is integrally molded with one side of the skirt 50, and can be displaced by ilexing the skirt 5) as shown in FIGS. 2 and 3. The rear end of the discharge pipe 54 merges integrally into a pushbutton 56, which can be depressed so as to actuate' a valve stem titl received within an opening 58 formed in the pushbutton S6.

The rear end 564 of the pushbutton is not connected to the adjacent part of the plastic skirt 50, so as to permit free vertical movement of the pushbutton. Such vertical movement causes the valve stem 60 to be reciprocated within a central opening of the first washer 38. Note that the inside diameter of the opening 18-4 in the valve support is somewhat larger than the outside diameter of valve stem 60 so as to' leave room for the injection of the Freon and shaving cream concentrate Z8 through the opening 18-4 and under the flange 183 when the can in initially filled.

At the interior end of the valve chamber 40 is a second Washer 62, formed of a silicone rubber material, which rests against a shoulder 3(13 formed in the interior wall of the valve housing 3f). The second washer 62 serves to seal off the interior of the activant bag 24 from the valve chamber 40. The inner end of the valve stem 60 reciprocates within a central opening of the second lwasher 62, and fits sufficiently closely within that opening so as to maintain the sealing relationship.

A sealing flange 64 is integrally formed with, and encircles, the valve stern 60 within the interior of the valve chamber 40. A steel coil spring 66 is in compression between the sealing flange 64 and a metal washer 68 overlying the silicone washer 62. Thus the spring 66 urges metal washer 68 and second washer 62 into sealing relationship with the seat 30-3, and the sealing flange 64 into sealing relationship with the first washer 38. The normal position of the valve stem 6i) is defined by contact of the sealing flange 64 with the first washer 38.

This normal position is illustrated in FIG. l, `where it is seen that the sealing flange 64 is pressed firmly into Contact with the first washer 38 and that the pushbutton S6 is urged outwardly from the aerosol can 9 to an unoperated position. Consequently, the skirt 50 is not flexed.

The valve stem 60 is formed with a blind central bore 70 which terminates at a surface 72. This bore 70 communicates with the interior of the discharge pipe 54 and thus provides the exit conduit through which the Freonpropelled shaving cream concentrate 28 and activant material 26 are ejected to the outer atmosphere, as represented by arrows 74. Entrance into the blind bore 70 is provided by a plurality of ports 76 formed in the wall of the valve stem 6ft. In the normal position of the valve stem 6G, as seen in FIG. l, each of the ports 76 is disposed within the central opening of the first washer 38, and in addition the sealing flange 64 makes sealing contact against the first washer 38 all around the valve stem 60, so that no material from the valve chamber 40 can have access to any of the ports 76. Thus, although the Freon and shaving cream concentrate 28, represented by arrows 80, have continuous access to the valve chamber 49 through a plurality of openings 82 formed through the wall of the valve housing 30, none of this material can escape s-o long as the valve stem 60 is in the normal position of FIG. 1.

Furthermore, when the valve stem 60 is in this normal position, the inner end 60-1 of the valve stem 60 blocks the central opening of the second washer 62, so that the activant material 26 in the bag 24 is prevented from passing the second washer 62 to enter the valve chamber 40. This prevents the activant material 26 from mixing with the Freon and shaving cream concentrate 28 in the valve chamber 40, and thus p-revents occurrence of the exothermic reaction inside the aerosol can 9 prior to dispensation.

In prior art valves of this type, the inner stem end 60-1 was received closely Within the opening 36 of the valve housing 30, and that fit was solely relied upon to.

seal oli the activant bag 24 from the valve chamber 40. That approach was unsatisfactory because the plastic materials of which the valve housing 30 and the valve stem 6l) are molded are not sufiieiently yieldable to provide a good seal. Consequently, there was contamination of the activant material 26 in the bag 24 by Freon and its iron chloride impurities, as well as escape of the activant 26 into the valve chamber 40 where it could react with the shaving cream concentrate 28 prior to dispensation.

The sealing flange 64, first washer 38, :and ports 76 are all parts of a first valving mechanism 94 which controls the exit of material from the valve chamber 40 to thel atmosphere. When it is desired to dispense the self-warming shaving cream mixture, the cam 9 is held in the upside down position as seen in all the drawings, and the pushbutton 56 is depressed upwardly to flex the plastic skirt 50 and drive the valve stem 60 upwardly, i.e. toward the interior of the can. When this is done, the sealing iiange 64 is moved upwardly out of sealing contact with the first washer 38 and the ports 76 formed in the wall of the valve stem 60 move upwardly so as to emerge from the opening of the first washer 38. This permits the contents of the valve chamber 40 to pass between the sealing fiange 64 and the first washer 38 and to escape through ports 76 into the bore 70 of the valve stem 60 as illustrated by arrows 84. From the blind bore 70 the material then passes through the discharge pipe 54 as illustrated by the arrows '74. The force for ejecting the material through these orifices is of course supplied by the pressure of the Freon propellant in the can.

At the same time that the rst valve means 94 is opened by the depression of the valve stem 60, a second valve means 96 including washer 62 and a keyway 90 is opened by the same motion of the valve stern to permit a proportional amount of the activant material 26 to escape from the bag 24 in the valve chamber 40. Beyond the surface '72 at which the blind bore 70 terminates, the valve stem inner end 60-1 is a solid cylindrical shaft of plastic material without any central openings, but the keyway is formed in the side of the stem end 60-1. The axial length of keyway 90 exceeds the combined axial thickness of the

washers

62 and 68, but when the valve stern 68 is in its normal position as illustrated in FG. 1, the innermost end of the keyway 96 is stored within the opening of the second washer 62, and thus does not extend into the interior of the bag 24. When the pushbutton 56 is depressed to drive the valve stem 60 toward the interior of the can, the innermost end of the keyway 90 then protrudes into the bag 24, while the outer end still communicates with the interior of the valve chamber 4i). Thus the keyway provides a channel through which the activant material 26 escapes from the bag 24 through the central opening in

washers

62 and 68 into the valving chamber 4f), as shown by arrows 92. The manner in which the keyway 96 provides such a channel is best illustrated in the sectional view of FIG. 4.

When the valve stem 60 is thusl actuated, the activant material 26, ejected by the pressure of the Freon propellanft in the can 9 which squeezes the flexible bag 24, enters the valve chamber 4t) and mixes` there with the shaving cream concentrate 28 which has already entered the valve chamber by means of the openings 82. Since the rst valve 94 is also opened at the sameI time, the mixture of activant 26 and concentrate 28 formed in the valve chamber 4u is simultaneously swept out through the ports 76 and discharged through the bore 70 and pipe 54 to provide a self-warming shaving cream mixture available for use outside the aerosol can.

It is a key feature of this invention that the keyway 90 is tapered with respect to its lateral width so that the interior end 90-1 is narrower and the exterior end 90-2 is wider. This enables the proportion of activant 26 and concentrate 28 to be maintained substantially constant regardless of how far the pushbutton 56 is depressed. In FIG. 2 the pushbutton 56 is shown depressed only slightly. Accordingly, only a relatively small portion of the length of the keyway 9) protrudes beyond the second washer 62. This means that the width of the keyway 90 at the point where it emerges from the second washer 62 is relatively small. It is this width which determines the effective crosssectional area of the esca-pe channel for the activant 26. Therefore, the activant 26 is allowed to escape relatively slowly into the valve chamber 40. This keeps the amount of activant in proportion to the amount of concentrate 28 which is allowed to escape through the relatively narrow opening between the sealing ange 64 and the first washer 33 when the valveY stem 60 is only slightly displaced, as seen in FIG. 2.

In contrast, FIG. 3 shows the pushbutton S6 depressed a substantially greater distance so as to displace the valve stem 60 further from its normal position. This means that a much greater space is opened between the sealing flange `64 and the first washer 38 so that a greater volume of shaving concentrate 28 is dispensed per unit time. In other words, the iirst valve 94 is opened wider. At the same time, the keyway 9) protrudes a greater distance into the bag 24 so that the wider part 99-2 emerges from the second washer 62 to provide a larger cross-sectional -area of conduit through which a greater volume of activant 26 can escape per unit time so as to maintain proportionality between the two materials being dispensed. It will therefore be appreciated that the proportionality between

materials

26 and 28 can be maintained substantially constant Whether the mixture is being dispensed slowly as in FIG. 2 or rapidly as in FIG. 3.

Another embodiment of the invention is illustrated in FIG. 5, which shows the interior end 269-1 of a valve stem 260 with a plurality of individual keyways 299 through 294. Each of these keyways is formed in the side of the valve stem 269 in much the same manner as the keyway 90 of the previous figures, but each one is straightsided. However the keyways 290 through 294 are staggered, i.e. they are spaced progressively greater distances from the inner end 260-1 of the valve stem 260. As a result, when the valve stern 260 is displaced, first the keyway 290 protrudes into the activant bag, then the keyway 291, and so on as the valve stem is displaced further. When only one keyway 290` is thus exposed, a relatively small channel area is provided for the activant. When two keyways 299 and 291 are exposed, the elective channel area is doubled, and so on as succeeding keyways protrude into the activant chamber.

Still another embodiment of the invention is illustrated in FIG. 6 where the interior end S60-1 of the valve stem 360 is formed with a keyway 390 tapered into the depth of the material rather than across the width of the keyway. When the valve stern 360 is depressed further, a greater depth of keyway protrudes into the activant bag and provides a larger cross-sectional area of conduit to maintain proportionality.

Still another embodiment, illustrated in FIG. 7, employs a different type of second valve 496. In this embodiment the interior end 460-1 of the valve stem 460 is provided with a sealing flange 499 surrounding the valve stem which abuts against the second washer 462 to form la seal which prevents the escape of the activant material when the valve stem 460 is in its normal position. There is also an elongated port 497 formed in the side wall of the valve stem 460 which communicates with an extension 495 of bore 470. When the valve stem 460 of this embodiment is depressed from its normal position, the sealing flange 499 comes out of engagement with the second washer 462 and a portion of the elongated port 497 protrudes beyond the second washer 462 to allow the activant material to escape through the port 497 and the bore extension 495 to the ybore 470 and the discharge pipe 454. If the valve stem 46d is depressed a small distance, a small length of the port 497 protrudes beyond the second washer 462 and thus provides a relatively small window through which the activant material can escape. When the valve stem 460 is depressed a greater distance, for faster dispensation of the shaving cream concentrate, the port 497 protrudes further beyond the second washer 462 and thus provides a larger window through which the activant can escape at a greater rate, thus matching the dispensation rates of the two materials to maintain proportionality.

One special advantage of the FIG. 7 embodiment is that, because the activant material is introduced directly through the port 497 and bore extension 495 into the bore 470, it does not pass through the valve chamber 440` and therefore does not come into Contact with the steel coil spring 466. Thus the spring is not as likely to corrode, because it avoids contact with the oxidizing activant material. Another special advantage is that the Freon and shaving cream concentrate are not mixed with the activant until both materials have passed through their rst and

second valves

494 and 496 respectively, and have entered the bore 470. Thus, when the

valves

494 and 496 are reclosed, none of the activant is left behind in the chamber 440 to contaminate the concentrate by finding its way back through openings 482 into the concentrate chamber. The mixing takes place in bore 470, which is open only to the ambient atmosphere once the valves have been reclosed.

In still another embodiment of the invention, illustrated in FIG. 8, the valve may be operated by a lateral motion which tilts the valve stem radially instead of displacing it axially. In this embodiment the discharge pipe 554 extends through an opening S50-1 in the skirt 550, instead of being integral therewith. A pushbutton 556 is pushed sidewardly as illustrated by arrow 557 so as to displace the valve stem 560` in a lateral rather than an axial direction. This causes the sealing ange 564 to come out of engagement with the iirst washer 538 at one side, to provide a space through which material can be dispensed as illustrated by arrow 584. In this embodiment, the ports 576 are normally disposed so that they protrude somewhat beyond the rst washer 538, and are thus accessible to the dispensed material when the seal between

elements

564 and 538 is disrupted. The material is then of course dispensed through the bore 570 and the discharge pipe 554.

The second valve 596 in this embodiment comprises a soft elastomeric second washer 562 without any metal thrust plate. An annular ridge 563 is formed on the valve seat and presses into the soft washer 562 so as to form a more perfect seal therewith. The valve stem 460 has a rigid tail piece 560-1 which normally tits closely within the central opening of the washer 562, but is displaced sidewardly to distort the opening and allow room for the activant material to escape as shown by arrows 592 when the valve stem 560 is sidewardly displaced. A conical spring 566 in compression between the washer 562 and the sealing flange 564 resists such sideward pressure on the valve stem 560 and restores it to its normal position after such pressure is discontinued.

In this embodiment also, proportionality is substantially maintained over a range of dispensation rates, since the degree of opening of the space between the sealing ange 564 and the iirst washer 538 will be substantially proportional to the degree of opening of the space between the tailpiece 566-1 and the washer 562. Thus, if the shaving cream concentrate is dispensed slowly, the activant material will be mixed slowly therewith, but when the concentrate is dispensed rapidly the activant will be mixed rapidly therewith.

It will now be appreciated that each embodiment of the present invention provides proportional mixing of the two materials over a range of dispensation rates, and in addition provides improved sealing of the activant reservoir so as to prevent internal contamination when the can is tilled, when the materials are stored in the can, and also after some of the material is dispensed.

The invention claimed is:

1. A valve for simultaneously dispensing and mixing two materials under pressure, said valve comprising:

a housing;

first and second washer means formed with respective central openings and spaced apart within said housing to deline a chamber therebetween;

a stem received within said two washer openings;

said stem being formed with an axial bore at one end thereof;

` said one end of said stem being received within the opening of a first one of said washer means;

the other end of said stem being received within the opening of a second one of said washer means;

said stem having a normal position relative to said washer means and being displaceable therefrom to perform a valving motion;

at least one opening extending through the wall of said housing between said washer means to admit a first material under pressure from a first volume into said chamber;

first valve means cooperating with said first washer and including at least one port opening through the wall of said stem into said bore;

said first valve means being arranged to seal oft` said port from said chamber when said stem is in said normal position but to open said port to said chamber when said stem performs said valving motion, to permit said first material to escape from said chamber through said port and said bore; and

second valve means cooperating with said second washer means and arranged to seal off a second volume beyond said second washer means when said stem is in said normal position but to open said second volume when said stem performs said valving motion;

whereby a second material under pressure in said second volume can then pass through said second valve means and at least indirectly enter said bore to be mixed with said rst material and codispensed therewith through said bore- 2. A valve as in claim 1, wherein:

said first valve means admits a greater quantity of material from said chamber as said stem is displaced further through said valving motion; and

said second valve means is arranged so as to present a greater opening to said second material as said stem is displaced further through said valving motion.

3. A valve as in claim 2, wherein:

said second valve means opening and the flow of material through said first valve means increase at substantially the same rate as a function of stem displacement;

whereby to maintain substantially the same proportion of said first and second materials codispensed, over a range of dispensing rates.

4. A valve as in claim 3 wherein:

said stem is axially reciprocable within said two washer openings to perform said valving motion; and

said second valve means includes axially extending keyway means formed in the outer surface of said stem;

said keyway means being positioned so as not to eX- tend beyond said second washer means when said stem is in said normal position, but to extend beyond said second washer means when said stem performs said valving motion;

the axial length of said keyway means substantiallyl exceeding the axial thickness of said second washer means to provide a channel through said central aperture of said second washer means during said valving motion, whereby said second material can pass through said channel and enter said chamber to be mixed with said first material and codispensed theresaid taper is in the width dimension of said keyway means extending across the outer surface of said stem.

7. A valve as in claim 5, wherein:

said taper is in the depth dimension of said keyway means extending transversely to the outer surface 0f said stern.

8. A valve as in claim 4, wherein:

said keyway means includes a plurality of individual keyways staggered so as to emerge sequentially from said second washer means.

9. A valve as in claim 1, further comprising:

annular means secured to said stem and engaging with said first washer means to establish said normal position and to form a seal for preventing material in said chamber from reaching said. port when said stem is in said normal position, but coming at least partly out of said sealing relationship therewith when said stem is -displaced to perform said valving motion;

a coil spring surrounding said stem and in compression between said annular means and said second washer means whereby to bias said annular means toward said first washer means to bias said first valve means closed and return said stem to said normal position;

the inner wall of said housing being formed with a shoulder; and

said second washer means engaging said shoulder and being biased thereagainst by said coil spring whereby to perfect the sealing of said second volume by said second valve means.

10. A valve as in claim 9, wherein:

said second washer means comprises an elastomeric washer adjacent said shoulder to effect a seal therewith.

11. A valve as in claim 10, wherein:

said second washer means further comprises a metal washer adjacent said coil spring to act as a thrust plate therefor.

12. A valve asin claim 1, wherein:

annular means are secured to said stem and engage 'with said first washer means to establish said normal position and to form a seal for preventing material in said chamber from reaching said port when said stem is in said normal position;

said first washer means is elastically deformable to permit said stem to be displaced radially to perform said valving motion.

said annular means coming at least partly out of said sealing relationship with said first washer means to open said chamber to said port when said stem is sufficiently displaced radially; and

said second valve means further comprises means in sealing relationship with said second washer means to seal off said chamber from said second volume when said stem is in said normal position, but arranged so that said sealing relationship therewith is at least partly disrupted to open said chamber to said chamber to said second volume when said stem is suiciently displaced radially.

13. A valve as in claim 12, further comprising:

a substantially conical coil spring surrounding said stem and in compression between said annular means and said second washer means whereby to bias said annular means radially toward the center of said first washer means to bias said rst valve means closed and return said stem to said normal position;

said means in sealing relationship with said second washer means comprising a shoulder formed on the inner wall of said housing;

said second washer means engaging said shoulder and being biased thereagainst by said coil spring whereby to perfect said sealing relationship.

14. A valve as in claim 13, wherein:

said second washer means comprises an annular elastomeric washer adjacent said shoulder to effect a seal therewith.

15. A valve as in claim 14, wherein:

said means in sealing relationship with said second washer means further comprises a tail-piece on said stem inserted into the central opening of said annular elastomeric washer and in sealing relationship therewith when said stem is in said normal position;

said elastomeric washer being sufciently deformable and said stem being suiciently rigid whereby said tail-piece distorts said central opening to disrupt said sealing relationship therebetween when said stem is suciently displaced radially.

16. A valve as in claim 15, wherein:

said first valve means admits a greater quantity of material from said chamber as said stem is displaced further through said radial valving motion; and

said second valve means is so arranged that said tailpiece is further displaced from said sealing relationship to admit a greater quantity of said second material through said second valve means in substantially the same proportion to said greater quantity of said rst material, as a function of said further stem displacement;

whereby to maintain substantially the same proportion of said iirst and second materials codispensed, over a range of dispensing rates.

17. A valve as in claim 1, wherein:

said stem is axially reciprocable within said central apertures of said rst and second washer means to perform said valving motion;

said bore extends substantially to the bounds of Said second volume;

said second valve means includes a second port opening through the wall of said stem into said bore extension; and

said second valve means is arranged so that said second port does not communicate with said second volume when said stern is in said normal position, but communicates with said second volume whenl said stem is driven axially toward said second washer to perform said valving motion;

whereby to permit said second material to escape from said second volume through said port directly into said bore.

18. A valve as in claim 17, wherein:

said second valve means further comprises annular means secured to said stem and engaging with said second washer means to form a seal preventing said second material from reaching said second port when said stem is in said normal position, but coming out of said sealing relationship therewith when said stem is driven axiallyl 'toward said second volume to perform said valv- 1ng motion;

whereby to open said second valve means by permitting said second material to reach said second port.

19. A valve as in claim 17, further comprising:

annular means on said stem engaging with said first washer means to form a seal preventing exit of said rst material from said chamber and to establish said normal stem position; and

a coil spring surounding said stem and in compression between said annular means `and said second washer means whereby to bias rst valve means closed and to return said stem to said normal position;

the inner wall of said housing being formed with a shoulder;

20. A valve as in claim 19, wherein:

said second washer means com-prises an elastomeric washer adjacent said coil spring to act as a thrust with.

21. A valve as in claim 20, wherein:

22. A valve as in claim 17, wherein:

said rst valve means admits a greater quantity o material from said chamber as said stem is driven further through said axial valving motion; and

said second port is positioned to increase the length thereof which protrudes into said second volume at substantially the same rate as said quantity oli material admitted through said rst valve means increases as a function of said axial displacement of said stern;

whereby to maintain substantially the same proportion of said rst and second materials codispensed; over a range of dispensing rates,

References Cited UNITED STATES PATENTS STANLEY H, TOLLBERG, Primary Examiner