US 3437270 A
Description (OCR text may contain errors)
April 8, 1969 SELF-SEALING SPRAY-ACTUATOR BUTTON Filed March 12, 1968 Sheet of2 i 1 'IIIIIJIIIII/ INVENTOR;
FRANK VENUS, JR.
BY FIG 3 MW ATTORNEYS F. VENUS, JR 3,437,? i
April 8, 1969 7' VENUS, JR 3,43 7,2 70
SELF-SEALING SPRAY-ACTUATOR BUTTON Filed March 12, 1968 Sheet 2 of 2 BY FRANK fNUS, JR I ATToRNEYs I N VEN TOR.
United States Patent 3,437,270 SELF-SEALING SPRAY-ACTUATOR BUTTON Frank Venus, Jr., Watertown, Conn., assignor to The Risdon Manufacturing Company, Naugatuck, Conu., a corporation of Connecticut Continuation-impart of application Ser. No. 562,142, July 1, 1966. This application Mar. 12, 1968, Ser. No. 712,429
Int. Cl. B05b 1/28, 15/02; B65d 83/14 US. Cl. 239-118 7 Claims ABSTRACT OF THE DISCLOSURE Actuator buttons for aerosol valves, in which the spray orifice of the button is normally blocked or closed in the non-dispensing condition of the valve, there being a diaphragm in the button which is flexed by admission of aerosol fluid under pressure when the valve is opened to unblock the spray orifice and allow discharge of the aerosol fluid, the blocking of the spray orifice reoccurring automatically upon subsidence of fluid pressure when the valve is closed.
This application is a continuation-in-part of my earlier application, Ser. No. 562,142, filed July 1, 1966, now abandoned.
This invention relates to nozzles for fluid dispensing,
and more particularly to spray-actuators which provide for finger operation of the typical valve of the so-called aerosol or self-pressurized dispensing packages, also pump type dispensing packages employing a manually operated plunger pump, to effect discharge of fluid product stored in the packages.
Spray-actuators of the type here concerned commonly take the form of molded plastic buttons of various shapes and sizes to permit one-finger operation of the valve or plunger of the dispensing package. The button is provided with a socket for receiving the tubular stem of the typical aerosol valve or plunger pump type, and with a discharge orifice communicating internally of the button with the stem-receiving socket to direct and control the delivery of the fluid product from the container in a desired manner. This delivery of the product may be in the form of a fine spray or mist, drops, foam or solid stream, depending on the nature of the product and the purpose to which it is to be applied.
One of the diificulties commonly encountered with spray-actuator buttons of the type mentioned is plugging of the terminal orifice or dispensing passages by reason of evaporation of the liquid product which remains trapped in such passages after each dispensing cycle. The difliculty is prevalent Where the product dispensed is high in solid material content the solvent or carrier is highly volatile, and especially if the discharge orifice is necessarily fine in order to achieve a desired spray or mist of the product. Various means of preventing or reducing the evaporation of the volatile portion of the product remaining in the terminal passages of the valve and actuator assembly have been the subject of considerable research. Typical solutions heretofore proposed are shown in US. Patents 3,146,922, 3,154,224, 3,155,291 and 3,161,331. However, the problem of plugging of the terminal orifice is still encountered under certain conditions and it is a purpose of the present invention to overcome the prior difficulties by a button of new and different design.
In summary, the invention herein disclosed contemplates a spray button having a main body and an orifice plate preferably formed of molded plastic. Suitable provision is made in the body to secure it to a valve stem or pump plunger tube to effect delivery of fluid to the 3,437,270 Patented Apr. 8, 1969 button from a supply reservoir. An interior passage in the button body leads from the stem or tube to an outlet in a face of the button from which the fluid is to be discharged. An annular abutment is disposed in the well to provide a sharp-edged recessed shoulder therein completely surrounding the center or axis of the outlet and disposed between the center and the point of inlet of the interior fluid passage to the outlet. The orifice plate is of a size and shape to completely cover the outlet, being held therein only by peripheral engagement with its wall to form a fluid tight seal at that point. The plate has a centrally located discharge orifice which coincides with the axis of the outlet, and the surrounding area of the plate is concave-convex and flexible, with the convex surface facing inwardly of the outlet and contacting the sharp-edged recessed annular shoulder. This formation of the plate causes it to act as a Belleville or disc spring with its central portion normally biased inwardly of the outlet but having the special meta-stable characteristic of this type of spring, namely that the force necessary to move the central portion outwardly against its bias increases to a maximum as the over-center position is approached; but once that position has been passed, then a lower force is all that is needed to maintain the spring in its maximum flexed position. Such a spring thus exhibits something of a toggle or snap action, although it will not remain in flexed, over-center position without continued application of some force.
The invention herein disclosed takes advantage of this disc spring principle in a unique construction of spray button wherein the orifice plate takes the form of a disc normally biased as above mentioned to abut on the sharpedge-d shoulder of the annular abutment in the well of the button. It thereby normally seals off communication between the atmosphere and the supply of fluid product to be discarged at a point close to but spaced from the discharge orifice itself. As a result, at most only a drop or two of trapped fluid is left exposed to evaporization, crystallization or polymerization in the nozzle body between periods of dispensing. When dispensing is desired, admission of fluid under pressure to the spray button causes that pressure to be transmitted initially to the outer flexible portion only of the diaphragm or disc, i.e. outside of the sharp-edged abutment which is an area appreciably less than the total diaphragm area. By proper design of this area, the total force produced on it by the initial fluid pressure in the diaphragm may be made to cause the whole diaphragm to snap outwardly over-cen ter, thereby removing the sealing contact between the diaphragm and annular abutment and allowing fluid to pass out through the discharge orifice. Since there is then a significantly larger area of the diaphragm exposed to the fluid pressure, the unit pressure necessary to hold the diaphragm in its flexed position can be lower than that initially required to snap it over-center. This is desirable to compensate for normal pressure drop as the fluid discharges through the orifice.
As is further explained hereinafter, it is sometimes desirable to incorporate a peg or pin located centrally of the well in the button body so that it projects axially of, or even freely into, the discharge orifice itself. Such a peg or pin can serve as a useful mechanical clean-out device, helping further to remove any traces of clogging residue that may be present immediately adjacent the orifice itself, as well as to reduce still further the volume of trapped liquid exposed to atmosphere at that point. Such peg however cannot be used effectively as the fluid sealing member itself in place of the previously mentioned annular abutment in the outlet. The reason is that there must be an appreciable diflerence in areas of the portion of the flexible concave-convex diaphragm exposed to fluid pressure when the diaphragm is initially in contact with the annular abutment and the area susequently exposed when the diaphragm has flexed to its over-center position. This area diflerence is needed to help produce a definite snapaction whereby the diaphragm moves rapidly from a fully closed to a fully open position. The difference in area is also desirable to compensate for the pressure drop in the system which occurs when the diaphragm is flexed and fluid is free to pass out through the discharge orifice, as mentioned above. If the sealing contact between the diaphragm and its abutment is made at or in the discharge orifice itself (as where a central peg projecting into the orifice constitutes the sealing abutment), the areas of the diaphragm exposed to supply fluid pressure is virtually unchanged in the flexed and unflexed conditions. Because of this it becomes difficult to design, and much more difficult to mass produce, an inexpensive spray button which will not be subject to diaphragm oscillation, giving rise to pulsation and uneven spray discharge of the fluid dispensed. Where, however, the ratio of diaphragm areas exposed to supply fluid pressure is appreciably different from unity in the flexed and unflexed conditions, as by placing the sealing abutment farther away from the discharge orifice in accordance with this invention, the tolerances to be maintained in production of the parts are not nearly so tight and diaphragm oscillation is much more readily avoided.
The invention also contemplates the incorporation of mechanical break-up means of the swirl chamber type acting on the fluid product adjacent the discharge point, whereby to effect the delivery of the product as a fine cone of spray.
The invention is illustrated by several embodiments shown in the accompanying drawings and described hereinafter. As is apparent from these embodiments, the invention may take a number of specifically different structural forms, and the appended claims are to be interperted accordingly without specific limitation to the illustrated details except as these are essential to accomplishment of the final result as hereinafter described and defined.
In the drawings,
FIG. 1 is a fragmentary view in side elevation, partly in section, of a portion of a typical aerosol dispenser and valve incorporating a spray-actuator button of the present invention;
FIG. 2 is an enlarged vertical cross-section of the discharge orifice portion of the button seen in FIG. 1, parts being broken away for simplification of illustration;
FIG. 3 is a cross-sectional view taken on line 33 of FIG. 1;
FIG. 4 is a fragmentary cross-sectional view similar to FIG. 2, wherein the nozzle plate is shown in fluid dispensing condition;
FIG. 5 is a plan view looking at the inner face of the nozzle plate or insert of the previous figures;
FIG. 6 is a fragmentary view in cross-section of a dispensing button of modified design incorporating the invention herein; and
FIG. 7 is a plan view looking at the inner face of the nozzle plate or insert of the button seen in FIG. 6.
In FIG. 1 there is illustrated a portion of a typical aerosol container to which is secured a valve assembly 22 of known construction having a spray-actuator button 24 incorporating the present invention, the button being mounted upon the visual hollow stem 26 of the valve assembly. The fluid product to be dispensed is normally held under the pressure of a propellant gas within container 20 by means of valve 22, but is released upon actuation of the valve for dispensing from an outlet chamber or well 28 formed in a lateral face of button 24. The button may convenient-1y be molded of plastic and provided with a socket 30 opening on tis under face within which stem 26 is telescopically received to form a fluid-tight connection. A chamber 32 within the button 4 communicates with socket 30 to receive fluid produce delivered through the stern of the valve.
Button 24 incorporates an inserted flexible orifice plate or diaphragm member 36, shown in greater detail in FIGS. 2, 3 and 5, having a fine-bore discharge orifice 38 located generally centrally thereof. Orifice plate 36 is of generally circular, cupped configuration and may be formed of suitable molded plastic, or of sheet metal, to provide a central, flexible, concavo-convex portion 40 immediately surrounding orifice 38. At its periphery, member 36 has an inwardly directed flange or wall 42 which is received in and makes a fluid tight fit in outlet 28 of the button. As illustrated in the embodiment of FIGS. 15, insert 36 is also provided with an inwardly directed hollow boss 44 having a central counterbore 46 concentric with and leading to discharge orifice 38. As seen best in FIG. 5, four slots 48 intersect boss 44 tangentially of counterbore 46 to feed fluid to a central swirl chamber 58 immediately up stream of the orifice in order to provide a cone of fine mist when the fluid discharges.
In the normal, non-dispensing condition of the actuator assembly illustrated in FIGS. 1-3, communication of air through orifice 38 to retain fluid in button 24 is blocked through abutment of the flexible diaphragm 40 against a sharp-edged annular shoulder 50 which loosely surrounds boss 44. This shoulder is recessed in outlet 28 of the button and is formed by a blind bore 52 let into the back wall of outlet 28. There is also in this instance a peg or pin 54 which projects axially outwardly of outlet 28 a short distance, and is loosely received in counterbore 46 of insert 36 to assist in forming swirl chamber 58.
When button 24 is operated to open valve 22 and deliver fluid product under pressure through stem 26 to chamber 32, the product passes into feed passage 56 and thence into an initial outer annular area 60 of outlet 28 surrounding boss 44. However, the fluid is initially blocked from passing through feed passages 48 of boss 44 to swirl chamber 58 by line-contact seal between the diaphragm portion 40 of the insert and shoulder 50. The pressure of the fluid introduced thus acts first on the under (convex) surface of the diaphragm in area 60 only to cause diaphragm 40 to flex outwardly, as seen in FIG. 4. As this occurs, the sealing abutment of shoulder 50 and diaphragm 40 is removed, and fluid is then free to pass inwardly through feed channels 48 to the swirl chamber 58 and out through orifice 38. At this point the whole convex surface of the diaphragm and not just area 60 is subject to fluid pressure, so that less pressure is required to hold it in the open position, due to the significant increase in effective diaphragm area thus brought into use. Upon release of the actuator button to return valve 22 to closed position, thereby cutting off further delivery of product under pressure to chamber 32, diaphragm 40 returns under its bias to its original (FIG. 2) position to re-establish the seal between the diaphragm and shoulder 50.
For some purposes it may be desirable to vary the depth of insertion of insert 36 in outlet 28 to increase or decrease the preload or biasing of flexible diaphragm 40 against shoulder 50. By so doing, the diaphragm may be preloaded to a position where it is just short of toggling or snapping over-center, so that a minimum initial fluid pressure is required to actuate it the rest of the way.
The modified design of spray button shown in FIGS. 6 and 7 is much the same as that already illustrated and will not be further described here in detail except to point out the differences. Such differences relate to the provision of mechanical means for cleaning out the discharge orifice and to a modified swirl feed arrangement.
Button 124 of FIG. 6 has its central peg or pin 154 extended forwardly (outwardly) terminating in a point or conical end face 160. In the normal, nondispensing condition of the button, this point partially enters the dis charge orifice 138. While a fluid seal may be effected at this point in this manner, the main purpose of the pin pro ecting into the orifice is to assist in mechanically dislodging any incrustation, or other blocking of the orifice that might be present, through relative motion of the diaphragm and pin or successive dispensing cycles.
In FIG. 7, a slightly ditferent swirl-forming configuration is shown. In this case, the central post 144 of the orifice insert 136 is intersected by a single pair of diametrically opposed tangential slots or cuts 148 which provide lateral communication between swirl chamber 158 and the source of fluid supply once the diaphragm seal has been removed.
The foregoing illustrate several modifications of the invention incorporating the concept of providing means for effecting a fluid seal adjacent to but spaced peripherally from the discharge orifice to take advantage of differential areas of the diaphragm accessible to fluid pressure in the closed and open positions of the diaphragm, whereby to provide an improved seal which is automatically established in the non-dispensing condition of the dispensing package but is removed by flexing of a spring disc or diaphragm relative to an annular shoulder surrounding the discharge orifice upon admission of fluid under pressure to the discharge button.
Although the presently preferred arrangement of the nozzle incorporates means for mechanically cleaning the discharge orifice automatically after each dispensing cycle, such is not essential to the invention in its broader aspects as exemplified by FIGS. 1-5'. Similarly, the provision of mechanical break-up means or swirl chamber behind the orifice to effect a fine mist type of dispersion is not essential to the basic inventive concept, and may be omitted where other forms of liquid discharge are desired. It will be apparent also that modifications of other details of construction can be incorporated without departing from the invention. For example, the securing of the orifice plate in the actuator body may be accomplished by a snap ring, or by molding a bead into the body and snapping the orifice plate beneath this bead. Direct sealing by heat may also be used of course where the materials employed permit this. In place of a separate orifice plate, one which is integrally formed in the body of the button may be substituted. In the latter case the abutment against which the diaphragm comes to rest would then be formed as a. separate member and inserted into the button from behind the diaphragm, using any of the means for securing it similar to those discussed for the orifice plate.
What is claimed is:
1. A spray-actuator button for fluid dispensers employing pressure to discharge a fluid product, said button comprising in combination a body having a socket for fluid-tight reception therein of a conduit member which serves to deliver fluid product under pressure to said body, an outlet in said body and feed passage means in said body providing communication between said outlet and socket;
an orifice plate positioned in and closing said outlet in said body said plate having a discharge orifice passing therethrough and located generally centrally of said outlet, and an annular flexible diaphragm portion surrounding said orifice,
and abutment means in said actuator button providing an annular shoulder in said body outlet and positioned to engage said annular flexible diaphragm portion of said orifice plate in the absence of fluid under pressure in said outlet to provide an annular seal about said orifice, said diaphragm portion and shoulder making said sealing abutment adjacent to but radially spaced from said orifice to provide outer and inner areas of said diaphragm portion subject to fluid pressure in said chamber, said inner area constituting a significant portion of the total diaphragm area so as to reduce the minimum fluid pressure necessary to maintain said diaphragm in non-blocking position after it has been moved to that position initially by pressure acting only on said outer area. 2. A spray-actuator button as defined in claim 1, wherein said flexible diaphragm portion is convexo-concave with the convex face thereof making said sealing abutment with said shoulder in said body outlet in the nondispensing condition of said button.
3. A spray-actuator as defined in claim 2, wherein said diaphragm portion is provided on its convex surface with a hollow boss surrounding said discharge orifice and forming a swirl chamber upstream thereof, said boss having at least one slot in its :wall intersecting said swirl chamber tangentially.
4. A spray-actuator button as defined in claim 2, wherein said orifice plate is secured in said body outlet so as to impart additional preload to the engagement of said shoulder by said diaphragm.
5. A spray-actuator button as defined in claim 4, wherein the orifice plate is positioned in said body outlet to provide a preload on said diaphragm just short of that required to snap it over-center.
6. A spray-actuator button as defined in claim 1, wherein said button body is provided with a peg projecting outwardly in said body outlet axially of said discharge orifice, said peg having a height just suflicient to cause its tip to project into said discharge orifice of said diaphragm in the non-dispensing position of the latter.
7 A spray-actuator button as defined in claim 6, wherein said diaphragm portion is provided on its convex surface with a hollow boss surounding said discharge orifice and forming a swirl chamber upstream thereof said boss having at least one slot in its wall itnersecting said swirl chamber tangentially, said peg being loosely telescoped in said hollow boss.
References Cited UNITED STATES PATENTS 2,913,749 11/1959 Ayres 40l196 2,954,904 10/1960 Potoczky 222402.11 3,161,331 12/1964 Murtha 222402.12 3,365,138 1/1968 Green ZZZ-402.1
FOREIGN PATENTS 565,999 12/ 1944 Great Britain.
M. HENSON WOOD, 1a., Primary Examiner. H. NATTER, Assistant Examiner.
US. Cl. X.R. 239534, 577, 579, 337; 222402.1; 401-