IL24302A - Spray valve with protruding stem - Google Patents

Description

SPRAT VALVE WITH PROTRUDING STEM Ό^Μ rfrj? ay πτππ mnot? This invention relates generally to pressurized packages and more particularly is concerned with a valve mechanism for use with a pressurized package.

The modern pressurized package with which the valve struc ture of the invention is associated is more popularly known as an aerosol spray package. The phrasa "pressurized packages is more apt since many of the pressurized products which are dispensed through the use of containers of this type do not really produce aerosol but produce atomLzation in the form of minute droplets or particles. The pressurized package normally consists of a steel canister which is constructed in such a manner as to contain the pressure to which the same normally will be subjected, this canister having a top opening with an outwardly curled lip. The filler who will normally complete the package, purchases the canister from one source and the valve mechanism that goes into the canister from another. The manufacturer of the valve mechanism sells the tiller a cover member which can be sealcad upon the opening of the canister and which carries the entire valve mechanism thereon. The filler, therefore, fills the package with the pressurized product, such as paint in a carrier of some kind and a suitable .propellant such as a low boiling point gas. This material may be introduced into the: canister before attaching the cover of the valve mechanism or afterwards.

There are several different ways to fill such canister.

A valve structure is desired which is suitable for all methods of fillin .

Two general types of valves are used in pressurized packages. One type of valve mechanism is that shown and described in U. S. Patent 2,777,735 characterized by a valve plunger wholly within the boss formed in the cover member and presenting a socket to an opening in the cover member. The sprayhead in this type of construction has a depending stem with a slot in the stem, and the stem must be inserted through the hole in the cover member past the rubber gasket into the socket formed in the valve plunger. Depressing the sprayhead therefore pushes the stem down and exposes the slot to the inside of the housing secured on the interior of the boss and connected with the bottom end of the canister by means of a dip tube .

The second type of valve mechanism is one in which the valve plunger has an integral stem protruding from the hole of the boss permanently so that the sprayhead is merely a button having a socket fitted over the protruding stem. In this type of structure, the bottom end of the stem being secured to the valve plunger, there had to be a hole drilled in the stem to be exposed when the stern was pressed downwardly.

Each of the valve mechanisms discu.sed above has its disadvantages. The first is expensive to manufacture and assemble and difficulties have been experienced in attempting ■ to lead the stem into the hole of the boss during assembly.

The second type of valve structure is cheaper but not versatile due to the limitations upon manufacturer required by the drillin of a hole and further it clo ed too easil and hence was unsuitable for the dispensing of heavy materials, such as, paint, starch, wax and similar suspended solids.

By "metering", it is meant predetermination of the spray rate, that is, the amount of spray material discharged per time unit.

The structure with the depending stem having als¾ot has become known world-wide as the best valve, for the dispensing of such solids, especially paint, because of the slot* .furthermore, adjustable spray rates can be obtained by changing the internal metering. It is desirable, therefore, to combine the best attributes of both types of valves in a valve assembly which inalades both the protruding 3tem e d a slot which controls the internal metering* Accordingly, the invention provides a spray can valve structure having a combined valve plunger and vertical, integral stem, said valve plunger being comprised of a body portion having a valve sea$ oa the upper portion thereof, said combined valve plunger and stem being biased upwards under the influence? of a spring with the valve seat in engagement with a gasket having a central opening, thereby preventing discharge of the pressurized product from the spray can, eaid stem being formed unitary with the upper end of said body portion and having a free end protruding above the 3pray can and adapted to be provided with a spray head, said 3tem having a vertical bore extending axially from the outer free end thereof to a point within the body portion that is axially spaced below the valve seat, and a metering orifice of predetermined cross section formed in the plunger or in the stem of the valve assembly in the area of the point of juncture of said stem and said body portion and communicating, with said axial bore; and said 3tem ¾aving a slot which extends radially outward from said bore and communioating with said metering orifice, said slot extending axially downwardly therefrom, toward the inner The invention also is characterized by a novel method of manufacturing a unitary plunger and stem valve structure wherein an axial metering slot is provided in said stem.

Further details and advantages of the invention will become apparent from the description of preferred embodiments illustrated in the accompanying drawings in which: Figure 1 is a fragmentary side elevational view of a pressurized package equipped with a valve assembly according to the invention and showing an environment in which the valve structure of the invention is capable of use.

Figure 2 is a median sectional view taken generally along the line 2-2 of Figure 1 and in the direction indicated.

Figure 2a is a transverse sectional view taken through the sprayhead of Figure 2 and in the direction indicated.

Figure 3 is an exploded median sectional view of the valve plunger and stem of Figure 2 prior to the assembly thereof.

Figures 4, 5 and 6 are sectional views taken generally along the lines 4-4, 5-5 and 6-6 of Figure 3 in the direction indicated .

Figure 7 is a bottom plan view of the stem of Figure 3 taken generally from the plane 7-7 and looking upward.

Figure 8 is a fragmentary enlarged sectional view of the valve mechanism of Fi ure 2 whereb the s ra head with the stem and the plunger is in depressed condition so that pressurized product is capable of escaping from the canister.

Figure 9 is a view similar to that of Figure 2 but showing a modified form of the invention.

Figure 10 is a view similar to that of Figure 3 but of a modified form of the invention and with the valve plunger and stem having its plug in position.

Figure 11 is a sectional view similar to that of Figure 4 but taken generally along the line 11-11 of Figure 10 and in the direction indicated.

Figure 12 is a sectional view taken along the line 12-12 of Figure 10 and in the direction indicated.

Figure 13 is a bottom plan view of the valve plunger and stem of Figure 10, but with the plug omitted.

Figure 14 is a side elevational view of the plug of Figure 10.

Figure 15 is a bottom plan view similar to that of Figure 13 but with the plug in place .

Referring now to the drawings, Figure 1 illustrates the which upper end of the pressurized package/is designated generally by the reference character 20 and comprises a cylindrical canister 22 having an upper dome 24 terminating in a curled lip 26 to provide an open top 28 which is closed by the cover member 30 that mounts the valve mechanism.

The cover member 30 comprises a sheet metal cuplike structure having an upper curled lip 32 adapted to be crimped over the li 26 and sealed b means of suitable asketin material 34 provided in the lip 32 by the valve manufacturer. The cover member has a well 36 in the center of which there is an integral upstanding generally cylindrical boss 38 having a central opening 40 in its top wall 42. The boss 38 is crimped to the outwardly flared upper end 44 of the valve housing 46 that depends from the interior of the boss 38, the crimps being shown at 48.

The housing 46 is sealed on its top end by means of a rubber -like gasket 50 sandwiched between the top wall 42 of the boss 38 and the flared upper end 44 of the housing 46.

The bottom end of the housing is pinched as at 52 to the upper end of the flexible dip tube 54 which extends downwardly to a corner of the canister 22 so that the pressurized material is permitted to flow up the dip tube and into the chamber 56 formed on the interior of the housing. 58 A valve plunger, designated generally 4&¾= is disposed within the chamber 56. The plunger 58 is best shown in Figures 3 through 7. Although the plunger is a unitary structure, it is actually made up of two parts in a manner to be discussed below.

The plunger consists of an enlarged generally cylindrical body portion 60 which is always contained within the housing 46 and an integral protruding hollow stem 61 that extends through a suitable opening 65 provided in the gasket 50 and through the opening 40 in the wall 42. Normally, the gasket 50 is in the shape of a flat annular disc when installed but assumes the general configuration shown somewhat as in Fi ure 2 during the assembly of the valve mechanism.

It will be seen that the stem 61 is slidably and sealing- ly engaged within the opening 65 of the gasket 50.

Continuing with the description of the valve plunger 58, at its upper end, the body portion 60 has an annular valve seat 62. This valve seat is spaced from the stem 61 by an annular gallery 64 whose purpose will be described. The bottom end of the body portion 60 is of reduced diameter as shown at 66 to provide a shoulder 68 for seating a helical spring 70 disposed in the chamber 56 and having its bottom end engaged at 72. The spring urges the plunger 58 upward so that seat 62 normally is biased tightly to engage against the bottom surface of the gasket 50. The pressurized material cannot escape from the chamber 56 while the plunger is in this position.

An internal slot is formed in the body portion 60 at 74, the slot communicating between the gallery 64 and the bore 76 of the hollow stem. If the stem 61 is pushed downwardly to unseat valve seat 62 from the gasket 50, the con-dition will be as illustrated in Figure 8. Pressurized material will follow the path taken by the arrows into the gallery 64 through the slot 74 and out through the bore 76. A suitable push button 80, molded as a unitary member of plastic, has a socket 82 to fit the upper end of the stem 61, the socket communicating with a small passageway 84 that leads to the external orifice 86. The pressurized material will be sprayed out of the orifice 86 when the push button 80 is depressed. If desired, external metering or mechanical break-up of the emerging material can be controlled by a suitable insert in the spray head, in a manner well-known in this art.

The only portion of the slot 74 which meters material passing through the slot will be the upper end 88 and by controlling the cross-sectional area of this portion of the slot the manufacturer can control the rate of flow.

The use of a valve structure in which there is a gallery is advantageous since the moment that the slightest unseating occurs there will be a large area over which the material may enter the gallery and pass through the upper end 88 of the slot 74. Slot 74 is advantageous since at the spraying of heavy material these materials will tend to continuously drain down to the bottom end of the slot thereby leaving the upper end clean.

As seen in Figure 3, before the valve plunger 58 is fully fabricated, it has a cylindrical socket 90 molded in its bottom end, the entrance to which, preferably, is tapered as at 92. This gives plenty of space to enable the introduction of molding tools to form the slot 74 and the bore 76 from the bottom end of the piece. The gallery configuration is readily formed by introducing molding tools at the top end of the piece. After the piece has been molded, a cylindrical plug 94 is forced into the socket 90 and is seated at 96.

This fully blocks off the bottom end of the bore 76 and becomes a part of the valve plunger 58. The recess 98 assists in enabling passage of the materials comin u the di tube through the chamber 56 past the spring 70. As indicated the spring engages upon the reduced diameter portion 66 and seats against shoulder 68.

Figure 9 illustrates structure which is quite similar to that described in connection with Figures 2 to 8 except in several respects.

In the first place, the valve structure of Figure 9 uses a plastic housing 46 and the dip tube 54 is locked into the bottom end of the valve housing by means of a split sleeve 100 frictionally engaging the housing and constrictively engaging the dip tube 54.

In the second place, the plunger body 60 does not have a structure like the gallery 64 of Figure 3, but instead the valve seat 62 is immediately adjacent the stem 61.

Because of the construction described involving the elimination of the gallery, it is necessary that the upper end of the slot 74, which is shown at 88, extend above the valve seat 62 and partially enter the gasket 50 when the spray button 80 is depressed. In the structure of Figure 9, the upper end 88 of the slot 74 will be exposed above the valve seat 62 and the materials passing from the chamber 56 enters the slot at this point.

In the structure of Figure 9, uniform spray can be obtained only by suddenly depressing the button to the fullest extent. Otherwise, more or less of the upper end 88 of the slot 74 will be exposed varying the spray rate.

Figures 10 to 15 inclusive illustrate another form of the invention which uses the same principles explained above, and which has the same advantages and perhaps additional features' hich will be mentioned. Since the construction of the plunger is the only part that is varied, these Figures show only this part. It is designated generally 158 in order to distinguish it from the other structures of Figures 2 through 9. The body portion 160 is substantially shorter in axial length, and the cylindrical bore 190 is substantially larger in diameter. (Note that the reference characters are similar to those previously used for the same parts, but with a prefix "1") . The plunger 158 has a hollow stem 161 having a hollow bore 176 which serves as the usual expansion chamber. The valve seat is shown at 162, spaced from the bottom end of the stem 161 by an annular gallery 164.

The principal difference between the plunger 158 and those previously shown is in the fact that the metering is controlled by an opening in the floor of the gallery 164 instead of in the side wall of the stem, as in the case of both versions previously described. As noted, the body 160 is provided with a radially extending slot 174, the upper axial end of which commences at the floor 165 of the gallery 164, and the lower axial end of which opens to the hollow bore 190 of the body 160. The opening which controls metering is shown at 188.

Another major difference between the structure of the plunger 158 and those previously described is that the body 160 has bee, simplified by eliminating the need for the spring seating means therefrom and instead, forming the same on the plug. The external surface of the body is simple and cylindrical, and likewise the bore 190 is concentrically cylindrical. The entrance is provided with a pilot taper 192 and, preferably, an annular ridge 193 is provided on the interior surface of bore 190 while another ridge 195 is provided in the surface 196. These ridges are quite small, being a few thousandths of an inch thick. When the plug 194 is forced into the bore 190, these ridges serve to provide a fluid tight and permanent connection. The ridge 193 bites into the side wall of the plug 194 and gradually sinks into a permanently locked position by cold flow. The ridge 195 does the same on the upper end of the plug 194. Thus, the chance of pressurized material getting past the plug 194 is substantially lessened, if not completely eliminated.

The plug 194 has a reduced diameter portion 166, split by the central recess 198 to permit the pressurized product to pass the spring which fits upon the portion 166 and seats upon the shoulder 168 formed by the reduced diameter portion 166.

The molding of the plug 194 has not materially increased in complexity over the simple plug 94 previously described, but the molding of the remainder of the plunger 158 has been simplified over plunger 58.

The structure of Figures 10 to 15 is advantageous in other regards . In molding techniques , it is easier to mold small openings where parts of the die come face to face than where these openings are on a plane which is defined by parts moving relative one another. Thus, the structure with the metering opening 188 in the floor of the gallery 164 is more reliably and easily manufactured than the others described. Also, in molding techniques, it is most desirable to have parts as large as feasible to prevent breakage, variations from dimensions caused by bending, and even more important to make the parts easier to manufacture. The structure of Figures 10 to 15 uses larger molding parts than the others described .

In Figure 10, the pin which molds the slot 174 is quite large and robust, because it will extend radially from the bore 176 to the left past the wall of the stem 161. In other cases the pin has always been not greater than the wall thickness of the stem. Note that it is a relatively simple matter to change the metering by increasing the radial size of the pin which is to form the slot 174, exposing more of the opening 188 ir. the floor 165, or by decreasing the radial dimension of this pin to provide a much smaller opening. In all cases, the pin will be quite sturdy.

The concept of an axially opening metering opening is believed novel in and of itself. Metering is more easily achieved and maintained . Drainage from the gallery is better.

The materials contemplated by the invention are moldable plastics of the thermoplastic variety, principally those of good stability - such as nylon. The plug is advantageously made of polyethylene, since any swelling will lock the plug tighter.

Claims (1)

1. A valve structure having a ned valve plunger and integral said valve plunger being comprised of a portion having a valve seat on the upper portion said combined valve plunger and being biased under the influence of a spring with the valve seat in engagement with a gasket having a central thereby preventing discharge of the pressurized product from the spray said being formed unitary with the upper end of said bein slidingly but sealingly engaged through said central opening portion having a free end protruding above the spray can and adapted to be provided with a said having a vertical bore axially the outer free end thereof to a point within the body portion that is axially spaced below the valve and metering of predetermined cross section formed in the plunger or in the stem of the valvo assembly in the area of the point of juncture of said stem and said body portion and with axial and said stem having a slot which extends radially outward from said bore and coraaunicating with said metering said slot extending axially downwardly therefrom toward the inner end of said bore and the inner end of the bore being valve structure according to Claim Ϊ said axial slot extends to the inner end of said bore and said bore is closed at this inner end in directio by means of a plug head inserted into a socket formed in the bottom of said The valve structure according to Claim wherein periphery the valve seat is contiguous immediately to the outer of said stem and said axial slot extends from said inner end of said in an axilil direction beyond said valve seat by an amount corresponding to the of said calibrated The valve structure according to claims 1 or wherein the valve plunger is provided with an annular recess surrounding said said opening towards the plunger front adjacent said gasket and said axial slot by means of said valve structure according to wherein the axial slot from the inner end of said bore in axial direction the bottom of the annular recess and into said recess by of said calibrated The valve structure according to wherein said axial slot extends from the inner ends of said bore in axial direction at to the inner surface of said The valve structure according to 4 wherein characterized in that axial slot extends in radial direction beyond the outer diameter of said into plunger and terminates by means of opening of calibrated cross section into the bottom of said annular The method for manuf cturing a combined valve plunger and of a valve structure according to any of the Claims said method comprises the steps molding as a unitary one pieoe member of a valve lunger body a valve a and a socket in the of said body with the bore and the bottom opening slot opening into the molding a plug head a separate molding sizing said plug such that its diameter is slightly larger than the diameter of the inserting the plug head into the socket in 3uch a manner that the resulting fit is en interference 9th 1965 FOR APPLICANT insufficientOCRQuality