IL37490A - Aerosol valve and sprayhead - Google Patents

Description

AEROSOL VALVE AND SPiiAYHEAD 'ϊϋ.

The invention herein relates to aerosol vales and more particularly is concerned with a novel metering valve construction for a pressurized package.

Aerosol valves include those in which there is a stem protruding from the package and a button is removably mounted on the stem, and those in which the stem and button are integral to provide a sprayhead that may be totally removed from the package. Somewha different techniques are used in gassing the two types. The invention herein is applicable to both types of aerosol valves and a principal attribute of the invention, namely accurate metering, is available for both constructions.

One problem involved in the use and manufacture of aerosol valves concerned the control of metering. Two factors tend to alter the metering originally built into the valves. In the so called slotted stem valve, one factor was the constricting force of the elastomeric gasket tending to close the slot and the other was the swelling of the resinous material from which the sprayhead was molded. In both cases, the tendency of the slot was to close, substan- tiaily changing the metering and often even closing the slot so that very little if any of the product could be passed. This was especially true in the case of very fine metering where the slot initially was quite small.

Because of the above factors, sprayheads of this type were made out of some synthetic resin which was relatively rigid. The degree of "cold flow" of this type of rigid polymerized synthetic resins is less than the softer resins, among which are polyethylene and polypropylene. The cost of the softer resins is substantially less than that of the rigid resins, but the latter were needed in order to maintain the metering dimensions originally formed. The problem of swelling is serious. Additionally, molding sprayheads with metering slots is expensive because of the cpmplexities of the molds and the need for maintenance and repair. Additionally, for every different type of metering, the molds must be different. Since the part of the sprayhead which is involved is so small, the difficulties involved/should be obvious.

The embodiments described achieve advantage over the prior art, primarily by providing a metering valve construction in which the metering remains constant for the life of the pressurized package and may be established accurately at the time of manufacture of the valve. This is especially advantageous for cases where the metering is fine. Additionally, the molds for the these sprayheads all are simple to manufacture and all are the same irrespective of the metering Additionally, instead of being molded of rigid resins, these sprayheads can be made of the softer resins, of which polyethylene and polypropylene are examples. Considerable cost savings are achieved by using the more economical of the resins, i.e., the soft resins. Further, the stem can be molded independently without any perforations and hence is capable of use for all meterings without change. The invention also is applicable to stem valves, Accordingly, the invention provides a valve assembly adapted to have a sprayhead mounted therein, the spra head v including an actuator button and a stem coupled together, the stem extending into the valve assembly from the exterior thereof, said valve structure comprising a cover member having a central passageway for movement of the stem therethrough, a gasket, a valve housing permanently secured to the inside of the cover member, a valve plunger in the housing having a valve seat on the upper end thereof and being spring-biased normally against the gasket, said housing having guide means for said valve plunger having an upwardly opening socket confined by the valve seat', the gasket being sndwiched between the valve housing and the cover member and having a central passageway therethrough aligned with the central passageway in the cover member, the socket being axially aligned with the passageways, the stem slidingly and sealingly passing through the central passageways into the socket and having its exterior wall soalingly engaged in said socket, the lower end of the stem is engaged in the socket being imperforate but for an axial end opening, the socket of the valve plunger is defined by a right cylindrical wall, said valve plunger having axially extending metering channel means on the interior of the socket opening at the upper end thereof adjacent the valve seat and passage means in the bottom of the socket providing communication between the lower end of said channel means A pln.No. 37490/2 The preferred embodiments of this invention will now be described, by way of example, with reference to the drawings accompanying this specification in which: Figure 1 is a fragmentary elevational view of the upper end of a pressurized package of the type in connection with which the nvention is used.

Figure 2 is a fragmentary median sectional view taken through the package of Figure 1 along the line 2-2 and in the indicated direction, the valve construction including a removable sprayhead and a plastic valve housing; Figure 3 is a sectional view taken generally along the line 3-3 of Figure 2 and in the indicated direction; Figure 4 is a fragmentary vie on an enlarged scale of a portion of Figure 2, illustrating the relationship of the parts during the time that the sprayhead has been depressed and pressurized product is being dispensed; Figure 5 is a perspective view in elevation of the valve plunger of the structure illustrated in Figures 2, 3, and 4; Figure 6 is a top plan view of the valve plunger of Figure 5; Figure 7 is a median sectional view of the valve plunger of Figure 5 taken along the line 7-7 of Figure 6 and in the indicated direction; Figure 8 is a fragmentary sectional view taken generally along the line 8-8 of Figure 7 and in the indicated direction; Figure 9 is a fragmentary sectional view taken generally along the line 9-9 of Figure 6 and in the indicated direction; Figure 10 is a view similar to that of Figure 7 but in this case, the construction is somewhat modified in that there is no gallery provided. Instead, the socket of the plunger has the same configuration from the bottom to the top edge thereof; Figure 11 is a fragmentary sectional view taken generally along the line 11-11 of Figure 10 and in the indicated direction; Figure 12 is a view similar to that of Figure 2 but illustrating a modified form of the invention in which the valve housing is metal and the valve is of the stem type; Figure 13 is a fragmentary sectional view taken through the structure of Figure 12 along the line 13-13 and in the indicated direction; Figure 14 is a fragmentary sectional view taken through a modified form of the invention in which there is a footing provided in the floor of the valve plunger socket to space the stem above the floor; Figure 15 is a sectional view taken generally along the line 15-15 of Figure 14 and in the direction indicated; Figure 16 is a sectional view taken generally along the line 16-16 of Figure 15 and in the direction indicated, this view being rotated 90 degrees relative to the view of Figure 14; Figure 17 is a fragmentary sectional view taken through a modified form of the invention in which a well is provided in the floor of the socket of the valve plunger; and Figure 18 is a sectional view taken generally along the line 18-18 of Figure 17 and in the indicated direction.

Referring to the accompanying drawings, in Figures 1 through 9, there is illustrated a type of valve construction in which the sprayhead is fully removable, there is a gallery in the upper wall of the socket of the valve plunger, and in which there is a plastic valve housing.

A preferred embodiment of the invention is designated by the reference character 20. This valve assembly 20 is purchased by the filler who puts it together with a canister 22 to make up the pressurized package, filling it with the propellant either before or after he installs the sprayhead or spray button, depending upon his techniques. Figure 1 shows a canister 22 which has a cylindrical body 24 that is held to a metal pressure dome 26 by a locked and sealed seam 28. The upper end of the dome 26 provides an opening or mouth 30 that has a rolled or curled formation 32. The valve assembly 20 is adapted to be mounted in the opening 30 and crimped in place as by the crimp 34, the seal being effected by the joint to be described.

The valve assembly 20 includes a metal cover member 36. that has an annular well 38 that surrounds an upstanding central boss 40 that is integral with the floor of the well and is formed from the same integral sheet metal member that constitutes the cover member 36. The upper edge of the cover member 36 is rolled as shown at 42 and this rolled edge engages over the rolled formation 32 surrounding the mouth 30 of the dome 26. A layer of gasketing material 44 between the rolled edges seals the cover member 36 into the opening 30 of the canister 22.

The valve assembly 20 includes a valve housing 46 which. is often called an eyelet in the trade, this housing in the structure being described being made out of some suitable plastic and having its upper end flared or enlarged to provide the flange 48 that engages into the boss 40 and is locked in place by means of the crimps 50. A disc-like elastomeric gasket 52 is compressed by the flange 48 against the inside of the upper wall 54 of the boss 40 so that the gasket 52 is sandwiched between the flange 48 and the upper wall 54. The upper wall 54 of the boss 40 has a central opening 56 and the gasket 52 likewise has a central passageway 58 that is aligned with the opening 56.

On its interior, the valve housing 46 provides a chamber 60 into which pressurized product is adapted to be introduced by way of the dip tube 62 that is locked to the bottom end of the housing 46 by any suitable means, such as the split locking collar 64. Any other method of securing the dip tube 62 may be used. In the chamber 60 there is a valve plunger 66 which provides ashoulder 68 and pilot projections 70 to seat a helical spring 72 that urges the plunger 66 upwardly as viewed, against the bottom surface of the gasket 52. The interior of the plunger 66 provides a socket 74 which has a blind bottom end which forms a floor 76, as best seen in Figures 6 to 9.

The upper end of the socket 74 has a gallery 78 that extends around the interior thereof, giving rise to a narrow section 80 that has an end surface 82. This end surface 82 is that which engages tightly against the bottom surface of the elastomeric gasket 52 as best seen in Figure 2 and comprises the valve seat. When the valve plunger 66 moves off the- gasket 52 as by being pushed downwardly, pressurized product from the chamber 60 will pass over the seat 82 and into the gallery 78, as best shown in Figure 4. The interior of the socket 74 has channels 84 and 86 formed therein, these channels opening at their upper ends into the gallery 78 and extending slightly below the floor 76 at their bottom ends. The channels 84 and 86 extend generally axially of the valve plunger 66, considering that its axis is vertical in Figures 2, 4 being the geometric center of the valve plunger as viewed, for example, in Figures 3 and 6. There are continuations of the bottom ends of the channels 84 and 86 formed in the floor 76, these comprising radially extending grooves 88 and 90, respectively. The radially innermost ends of the grooves 88 and 90 end at the center post 92, this post being integral with the valve plunger 66 and extending upwardly from the floor 76.

A sprayhead 94 is mounted in association with the valve assembly 20, the sprayhead comprising a button 96 with an integral, hollow bore stem 98 depending from the bottom of the button. The stem 98 has a central expansion chamber 100 which leads to a transverse passageway 102 in the button 96 connecting the external spray orifice 104 with the said chamber 100. The bottom end of the stem 98 has a slight chamfer at 106 as shown in Figure 4 to assist in guiding the stem through the gasket 52 and into the socket 74 when the sprayhead 94 is. assembled to the valve assembly 20. At its bottom end, the interior hollow chamber 100 is of such diameter that it clears the post on the interior of the stem by a substantial amount, as best seen in Figures 3 and 4.

As for its exterior dimension, the diameter of the stem 98 is such as to provide a relatively tight sliding fit with the socket 74. In this manner, since the stem 98 is imperforate except at its axial bottom end, no pressurized product can escape from the valve chamber 60 except by way of the channels 84 and 86 and their grooves 88 and 90.

In prior structures, the post 92 has served as an. assist in guiding and seating the stem in the bottom of the socket, and in such cases, the outer diameter of the post was the same as the inner diameter of the bore of the stem. In this case, since it is required that there be a space to enable the pressurized product, to enter the lower end of the expansion chamber 100 and move past the post 92, the outer diameter of the post 92 is substantially less than the inner diameter of the bore 100. The primary purpose for the post in the construction which is illustrated is to enable gassing the pressurized package. Otherwise, the post 92 is not essential to the operation of the valve structure.

The operation of the aerosol valve of the invention is best described in connection with Figures 2 and 4. In Figure 2 the valve is closed, with the valve seat 82 tightly pressed against the underside of the gasket 52. Under these circumstances ho pressurized product can escape from the valve chamber 60. The entire sprayhead 94 may be removed from the valve assembly 20 if desired without affecting the inoperative condition.

With the sprayhead 94 in place, when it is desired to dispense pressurized product, the button 96 is pressed downward and the lower end of the stem 98 engaging against the floor 76 of the socket 7.4 of the valve plunger 66 forces the plunger downward against the bias of the spring 72 to the position which is illustrated in Figure 4. When this occurs, pressurized product generally follows the lines of the arrows illustrated in Figure 4. It rises in the chamber 60 to the top of the plunger 66, passes over the valve seat 82 and into the gallery 78. From the gallery 78, the pressurized product passes down the channels 84 and 86 to the grooves 88 and 90, these latter being formed in the floor 76. The pressurized product now passes the end of the stem 98 and moves to the interior bore of the stem, passing upward between the inner surface of the stem 98 and the outer surface of the post 92 into the expansion chamber 100 and thence out to the atmosphere by way of the passage 102 and the orifice 104.

To discontinue the spraying of the aerosol product, the button 96 is released by the user and the sprayhead 94 moves upwardly because of the spring 72, thereby closing the valve due to the valve seat 82 once more engaging against the underside of the gasket 52.

While there are advantages in having a gallery as 78 in connection with the apparatus, it is not essential to the operation of the invention, and the principal advantages are achieved without the use of a gallery. For example, in Figures 10 and 11 the gallery is omitted. In this case, the valve plunger 110 is constructed in the same manner as the valve plunger 66 of Figures 1 through 9, except that the channels 112 and 113 which are the equivalent of the channels 84 and 86 respectively of the valve assembly 20 end at the valve sea 114. The valve seat 114 is substantially wider than the valve seat 82, since it is formed by the upper end of the wall 116 which forms the socket 118 of the plunger 110.

From the above description, it will be noted that the stem 98 of the sprayhead 94 is imperforate except where its hollow bore 100 opens to the bottom of the stem. There are no holes or slots to be molded into the stem, making its manufacture economical on account of relatively simple molds. Further, since there are no slots or holes which control the metering of the valve structure, only one design of sprayhead is needed for all meterings of valve structures The metering is provided elsewhere. Since there are no holes or slots, and no tolerances to be maintained to preserve metering^ the sprayhead may be molded from the economical soft plastics instead of the expensive rigid plastics Examples of such economical soft plastics are polyethylene and polypropylene. These are more economical than nylon, Delrin, Celcon or any other of the rigid plastics.

The metering is established by the dimensions of · the channels 84 and 86 in the case of the valve assembly 20 and the equivalent channels 112 and 113 of the structure illustrated in Figures 10 and 11. The passageway defined by the channels and the exterior surface of the stem 98 will control metering, the total rate being the sum of the cross sections of both channels in each case. Two channels are shown in the structures described, but obviously for greater flow rates i more than two channels can be used. Obviously there will have to be additional grooves cut in the floor of the socket as well. Under some circumstances, even a single channel with floor groove could be sufficient. Since the interior of the valve plunger is not subjected to constricting pressures, the channels are not likely to close down. Further, since the channels and grooves are fully backed up and are in a member having greater diameter than the stems, swelling or other stress is less likely to affect the dimensions of the channels and grooves. Accordingly, the metering is more accurate and will remain accurate over the lifetime of use of the pressurized package. Also, this type of structure is more economical to mold than the stems with slots because the molds are not as complicated.

Figures 12 and 13 illustrate another form of the invention which differs from the structures thus far described in which the sprayhead is formed of two parts, namely, the stem and the button. The valve assembly also is made somexvnat differently to illustrate the fact that the invention is capable, of considerable variation in its embodied form.

The valve assembly 120 is shown in Figure 12 comprising a cover member 122 of metal and a central boss 124 also of metal,, as in the case of the structure of Figures 2 and 4. The eyelet or valve housing 126 in this case is also of metal instead of plastic. It has the flanged upper portion 128 which is crimped in place by the crimps 130 sandwiching the elastomeric gasket 132 between the flange 128 and the lower face of the upper part 134 of the boss 124.. The valve plunger 136 is again biased upward by a spring 138 and the construction of the plunger is not substantially different from the plungers 66 and 110 previously described. The pressurized product is led from the interior of the canister to the chamber 140 formed in the valve housing 126 by way of a dip tube 142 whose upper end is crimped to the bottom of the valve housing 126 at 144.

The sprayhead 146 in this instance is made up of a button 148 and a separate stern 150. The stem 150 is forced into a permanent engagement with the socket 152 of the valve plunger 136, there being a slight ridge 154 on the interior of the socket designed to engage the outer surface of the stem to hold the same in place. Such ridges are readily molded in synthetic resins are are soft enough during the molding process to enable removability from the mold.

These ridges will: regain their shape immediately after the pieces are removed from the mold. The pressure of the ridge causes cold flow of the stem wall where engaged and the resulting joint is quite tight. The valve plunger 136 has a galler 156 and valve seat 158. Axially extending channels 160 and 162 are provided in the interior of the socket 152 connecting with a groove 164 formed diametrically in the floor 166.

It will be noted that there is no post in the center of this valve plunger 136 like the post 92 of the previously described structure. The gassing of pressurized packages having stem valves is done by techniques which differ from those used to gas pressurized packages that have removable sprayheads. In this case, since the stem 150 is permanently secured within the valve plunger 136 and will protrude from the boss 124 at all times, the button 148 being removable therefrom, there is no need for a central filling post. For this reason, the groove 164 in the floor 166 may extend fully across the floor.

The stem is best molded from the rigid plastic material discussed above, but the button 148 is easily molded from economical soft plastics of the polyethylene type. The remainder of the construction is obvious from Figures 12 and 13,. and the. operation is simply the depressing of the button 148 to move the valve seat 158 downwardly off the surface of the elastomeric gasket 132 against the bias of the spring 138. Release of the button closes the valve.

In Figures 14, 15 and 16 there is illustrated an embodiment of the invention in which there is no groove in the floor. Instead, there are ridges or footing to space the bottom end of the stem above the floor to permit the pressurized product to enter the bottom of the bore 196 of the stem. There is no need to extend the axial channels below the level of the floor. As shown, the valve plunger 170 has the socket 172 formed therein into which the lower end of a removable stem 174 is slidably fitted. There is a gallery 176 which is formed just below the valve seat 178 at the upper end of the wall 180. The channels 182 and 184 are formed in the wall inside of the socket 172 and these open at their upper ends into the gallery 176, but their lower ends terminate at the floor 186. In this construction, since the stem 174 is intended to be integral with the button of the sprayhead, the post 188 is provided to enable gassing by the technique mentioned above.

In the absence of grooves in the floor 186, means are required to space the bottom end of the stem 174 above the floor so that the pressurized product will move from the channels 182 and 184 past the stem wall to its center bore. For this purpose ridges 190 and 192 are molded integral with the floor 186 so that the stem bottom stands off the floor as best seen in Figure 14. In the event that the post 188 were not used, the ridges 190 and 192 could be combined to extend fully across the floor. Small protrusions from the floor or side wall in place of these ridges would perform the same function. Ridges 190 and 192 function as footing means.

In Figures 17 and 18 there is illustrated another embodiment of the invention in which the valve plunge 200 has a stem 202 engaged in the socket 204 thereof without a center post. This could be either a permanent connection as, for example, in the case of a stem valve or the stem 202 could be integrally connected with a spray button. The channels 206 and 208 are provided in the socket in the wall 210 with their upper ends opening into a gallery 212 and their lower ends extending below the floor 218 and opening to the grooves 214 and 216, respectively. These grooves are shown slanting slightly downward toward the center of the floor and terminating in a relatively large well 220.

The purpose of this well is to accumulate drainage of residue between uses of the aerosol package. In this way, heavy materials which might be suspended in the propellant and which adhere to the walls of the stem 202 and in the channels 206 and 208 will drain down into the well 220, thus decreasing the possibility of clogging, the channels or grooves. The same effect can be achieved in some of the other forms of the invention by deepening the grooves formed in the bottom of the floor.

The invention is applicable to the so-called tilt type of valves. In these valves the opening in the cover member such as for example opening 56 of the assembly 20 of Figures 1 to 9, is slightly larger in diameter than for a sprayhead that only slides vertically. Thus, tilting can be accomplished. Additionally, the upper end of the valve plunger is enlarged to provide a valve seat that is much larger in diameter than those shown. This enables a fulcrum effect during tilting of the sprayhead. The metering in such tilt valves will be built into the plunger structure exactly as described hereinabove.

The preferred embodiments of the invention will be described herein as mounted to canisters, but it should be kept in mind that the invention is equally advantageous when the container for the pressurized product is a bottle.

Claims (13)

Δρρΐη.No.37490, C L A I M S t

1 · A valve assembly adapted to have a sprayhead mounted therein, the sprayhead including an actuator button and a stem coupled together, the stem extending into the valve assembly from the exterior thereof, said valve structure comprising a cover member having a central passageway for movement of the stem thetethrough, a gasket, a valve housing permanently secired to the inside of the coyer member, a valve plunger in the housing having a valve seat on the upper end thereof and being springbiased normally against the gasket, said housing having guide means for said plunger, the valve plunger having an upwardly opening socket confined by the valve seat, the gasket being sandwiched between the valve housing and the cover member and having a central passageway therethrough aligned with the central passageway in the cover member, the socket being axially aligned with the passageways, the stem slidingly and sealingly passing and bottomed therein through the central passageways into the socket /and having its exterior wall s ealingly engaged in said socket, the " which lower end of the stem /is engaged in the socket being imperforate but for an axial end opening, the socket of the valve plunger is defined by a right cylindrical wall, said valve plunger having axially extending metering channel means on the interior of the socket opening at the upper end thereof adjacent the valve seat and passage means in the bottom of the socket providing communication between the lower end of said channel means and said axial end opening when the stem is disposed in the socket.

2. A valve structure according to claim 1 in which the means in the bottom of the socket comprise groove means in the floor communicating with the bottom end of said channel means, the lower end of the stem wall is in engagement with said floor, and said groove means extend from said channel means to the axial end opening past the lower end of the stem wall.

3. A valve structure according to claim 1 in which the means in the bottom of the socket comprise footing means spacing the lower end of the stem wall above the floor.

4. A valve structure according to any one of claims 1, 2 or 3 in which the stem and actuator button are separable and the' stem is substantially permanently engaged in said socket.

• 5. A valve structure according to any one of claims 1, 2 or 3 in which the stem and actuator button are integral and the stem is removably engaged in the socket.

6. A valve structure according to any one of claims 1 to 5 in which there is a gallery at the upper end of the plunger and the, upper end of the channel means open into the gallery, the gallery being disposed below the valve seat.

7. A valve structure according to any one of the preceeding claims in which movement of the actuator button and the stem is along the axis of the stem and socket and when moved against said bias, said valve seat is unseated.

8. A valve structure according to any one of the preceeding claims in which means are provided to accumulate residue in the floor of the socket without interfering with passage of pressurized product by way of said metering channel means and groove means.

9. A valve structure according to any one of the preceeding claims in which the metering channels are uniform in dimension along their length.

10. A valve structure according to any one of the preceeding claims in which the stem and socket are right-cylindrical in configuration.

11. A valve structure according to any one of the Appln.No. 37490/¾ 3 ^ preceding claims in which the stem is spaced from the bottom of the socket at least over a portion of the lower end of the said stem*

12. The valve assembly according to any of claims 1 to 11 in which the bottom floor of the socket includes an integral central upwardly extending center post.

13. The valve assembly according to any of claims 1 to 11 in which the socket of the valve plunger has an outer cylindrical wall and a blind bottom floor with an upwardly extending center post and the axial end opening of the stem telescopically engages and is spaced away from the center post providing the only entrance to the interior of the hollow stem from the bottom thereof. Tel-Aviv, July 19, 1971 \