US3913803A

US3913803A - Aerosol valve actuator with front end discharge governor

Info

Publication number: US3913803A
Application number: US535081A
Authority: US
Inventors: Robert H Laauwe
Original assignee: Robert H Laauwe
Current assignee: Inopak Ltd
Priority date: 1974-12-20
Filing date: 1974-12-20
Publication date: 1975-10-21
Anticipated expiration: 1992-10-21

Abstract

An aerosol valve actuator has a body in which a forwardly open cavity is formed and which contains in its forward end a reciprocating piston in which a discharge orifice is formed, a rod or probe extending from the closed back end of the cavity forwardly and having a front end which normally closes the discharge orifice when the piston is at a backward position, but opens this orifice when the piston reciprocates forwardly to leave the front end of the rod or probe. A hole opens transversely through the body and into the back end portion of the cavity and this hole is proportioned for a press fit on the usual tubular valve stem through which a packaged pressurized product is dispensed when the stem is depressed. The actuator is used for depressing the stem by finger pressure. The front end of the body has a cap or retainer screwed on it to hold the piston normally backwardly against the front end of the rod, unscrewing of this cap freeing the piston for forward movement and orificeopening action. When the cap is unscrewed to place the actuator in its ready condition, a coil spring positioned between the cap and the piston biases the piston backwardly so that the orifice remains normally closed, the orifice opening when the actuator receives the pressurized product which then applies its pressure against the piston to push it forwardly to the limit determined by the extent with which the front cap is unscrewed. Thus, the cap acts as a governor controlling the extent the discharged valve opens and, therefore, the nature of the discharge of the pressurized product. This governor is positioned on the front end of the actuator.

Description

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Laauwe States ate t [191 Oct. 21, 1975 AEROSOL VALVE ACTUATOR WITH FRONT END DISCHARGE GOVERNOR Primary Examiner-Stanley H. Tollberg Attorney, Agent, or Firm-Kenyon & Kenyon Reilly Carr & Chapin [57] ABSTRACT An aerosol valve actuator has a body in which a forwardly open cavity is formed and which contains in its forward end a reciprocating piston in which a discharge orifice is formed, a rod or probe extending from the closed back end of the cavity forwardly and having a front end which normally closes the discharge orifice when the piston is at a backward position, but opens this orifice when the piston reciprocates forwardly to leave the front end of the rod or probe. A hole opens transversely through the body and into the back end portion of the cavity and this hole is proportioned for a press fit on the usual tubular valve stem through which a packaged pressurized product is dispensed when the stem is depressed. The actuator is used for depressing the stem by finger pressure. The front end of the body has a cap or retainer screwed on it to hold the piston normally backwardly against the front end of the rod, unscrewing of this cap freeing the piston for forward movement and orificeopening action. When the cap is unscrewed to place the actuator in its ready condition, a coil spring positioned between the cap and the piston biases the piston backwardly so that the orifice remains normally closed, the orifice opening when the actuator receives the pressurized product which then applies its pressure against the piston to push it forwardly to the limit determined by the extent with which the front cap is unscrewed. Thus, the cap acts as a governor controlling the extent the discharged valve opens and, therefore, the nature of the discharge of the pressurized product. This governor is positioned on the front end of the actuator.

5 Claims, 7 Drawing Figures Sheet 1 of2 US. Patent 001;. 21, 1975 US. Patent Oct. 21, :975 Sheet 2 of2 3,913,803

AEROSOL VALVE ACTUATOR WITH FRONT END DISCHARGE GOVERNOR BACKGROUND OF THE INVENTION The US Laauwe Patent application Ser. No. 490,077 filed July 19, 1974, discloses an aerosol valve actuator of the non-clogging type but having many advantages over prior art non-clogging actuators. Briefly stated, that actuator has a body through which a pas sage is formed, the front end having a closing wall in which a discharge orifice is formed. A reciprocative piston is positioned in the back end with a rod or probe extending forwardly to close the orifice when the position is at an advanced position and opening the orifice when the piston is at a retracted position. The body has a hole opening to the passage at a position spaced backwardly from the orifice end and which is fitted on the end of an aerosol valve stem so that when the body is depressed the stem is depressed to open the aerosol valve. A spring biases the reciprocative piston forwardly so that the actuators discharge orifice is normally closed.

The back end of the body behind the piston has external screw threads and a cap having internal threads is screwed thereon, the inside of the cap providing an abutment for limiting the backward or retracting motion of the piston.

That construction has many advantages among which is the fact that the cap on the back end of the body provides the actuator with a governor for governing the spray discharge. In addition, by screwing this cap or governor completely in, the piston can be locked in its forward position holding the discharge orifice positively closed, permitting the various available so-called child-proof cap arrangements to be used.

Although this earlier actuator has excellent nonclogging characteristics, because the orifice is normally closed to prevent internal concentration of solids such as crystalline material, pigments, and the like, by evaporation of the products carrier or due to other reasons, it is possible to completely unscrew the governor cap so that the spring and piston and the rod projecting from the piston for controlling the orifice, can all be removed, permitting inspection and possible cleaning. With the actuator thus disassembled, it is possible for extremely careless members of the public to press the actuator to open the aerosol valve with the result that the pressurized product discharges backwardly. Normally aerosol valve actuators have an arrow or other indicia applied to them to show the direction of discharge, which, with the actuator disassembled as described, is exactly opposite to the direction in which the major portion of the discharge can occur when the actuator has its inner parts removed.

Therefore, it has become desirable to provide an actuator having the advantages of the described earlier Laauwe actuator but which eliminates the chance, however remote, that the actuator might be used to operate the aerosol aalve and provide the backward discharge, when the actuator is disassembled.

SUMMARY OF THE INVENTION According to the present invention, the governor cap is positioned on the front or discharge end of the actuator. Therefore, if the governor cap and the reciprocating piston are removed for any reason, and the actuator on the stem of an aerosol package is carelessly pressed,

the discharge is forwardly as the person involved would expect it to be.

To do this, the actuator has a body forming a substantially cylindrical cavity with a permanently closed end back wall and with an open front end, the body having a hole opening transversely through it and into this cavity, adjacent to the back wall and adapted to receive the aerosol valve stem with the usual press fit. A stationary rod or probe extends from the back wall and projects towards the open front end, preferably substantially coaxially with the cylindrical cavity, and a piston reciprocates in this cavity and has a discharge orifice, but otherwise closing the cavitys open end, the stationary rod having a front end positioned to close the discharge orifice in the piston when the piston moves backwardly against this rod, and to open this orifice when the piston moves forwardly.

The governor cap is now screwed on the front end of the body with an opening providing the pistons discharge orifice with complete clearance, a spring being positioned in an annular recess formed in the front end of the piston around its discharge orifice, which is centrally positioned, the spring having an end bearing against the inside of the cap to spring-bias the piston to move backwardly to a retracted position where the inside of the piston around the discharge orifice presses against the front end of the stationary rod or probe for orifice-closing action.

In use, as before, a spray discharge can be governed by screwing this front governor cap in and out, thus controlling the possible displacement of the piston relative to the stationary rod or probe. When the cap is screwed completely inwardly, the piston is pressed positively against the rod or probe so that the discharge orifice is positively closed. Unscrewing of the cap governor more or less permits the piston to move more or less forwardly when its back receives the force of the pressurized product entering the back portion of the cavity, when the actuator is used to open the aerosol valve. In this way, the discharge of the product may be governed as before.

However, if an extremely careless person uses the actuator when disassembled, with the governor cap, piston and spring removed, the discharge is forwardly in the direction it would be normally expected to occur. In other words, with the actuator provided with the usual directional arrow or the like, the discharge would be in the direction of the arrow.

It is to be understood that such an accidentally produced discharge would not produce the desired type of spray, this requiring that the actuator be assembled with all of its parts in place.

BRIEF DESCRIPTION OF THE DRAWINGS The presently preferred mode for carrying out this invention is schematically illustrated by the accompanying drawings in which:

FIG. 1 is a vertical section of a hand-held aerosol package to which the actuator is applied;

FIG. 2 is a vertical section through the actuator showing it in its positively closed or locked position;

FIG. 3 is an exploded view showing how the parts disassemble to leave the front of the cavity in the actuator body, completely open;

FIG. 4 is the same as FIG. 2 but shows the actuator with its governor cap unscrewed to put the actuator in a ready-for-use condition;

FIG. shows the actuator in its operating phase, although with the understanding that the displacement of the piston is greatly exaggerated as to extent, for illustrative purposes;

FIG. 6 is a cross section taken on the line 66 in FIG. 5; and

FIG. 7 is the same as FIG. 4 but shows a modification.

DETAILED DESCRIPTION OF THE INVENTION Having reference to the above drawings, FIG. 1 shows what is, excepting for the new actuator, a prior art hand-held aerosol package comprising the usual can body 1 having what may be a conventional aerosol valve 2 and with the product 3 contained by a flexible bag 4 and pressurized by a small amount of propellant 5 in the bottom of the can. The vapor from this propellant is applied uniformly to the entire extent of the bag 4, so the product 3 is pressurized whether or not it contains any propellant in its formulation. An example of the can illustrated is the Power-Flo type of container disclosed by the Bruce et al. US. Pat. No. 3,392,842, dated July 23, 1968. However, the actuator of this invention may be used with any of the aerosol package types provided with an aerosol valve and containing a pressurized product. The new actuator is shown at 6 in FIG. 1.

The details of the new actuator are shown by FIGS. 2 through 5, as comprising a body 7 having a substantially cylindrical cavity 8 with a closed end back wall 9 and an open front end 10. The body 7 has a hole 11 opening into the cavity adjacent to its back wall 9 and adapted to receive the valve stem 12 of the aerosol valve 2, for example. In addition, the body has a rod or probe 13 projecting from the back wall 9 towards the open front end 10.

All of the actuator, as described so far, may constitute a single injection-molded plastic piece, the rod or probe 13 being integral with the back wall 9 and, therefore, being a stationary or fixed part of the body. On the outside the body may have a discharge direction indicator as shown at 14 in FIG. 3.

The reciprocating piston is shown at 15, slidably fitting the cylindrical cavity wall 8 and having an axially positioned product discharge ,orifice 16. The rod or probe 13 is positioned coaxially with this discharge orifice 16 and axially coinciding with the axis of the cylindrical wall 8 of the cavity. The front end 17 of the rod forms a valve head seating against the inside of the piston around its cavity 16, and controlling the discharge through this orifice 16.

The front end portion of the body 7 has external screw threads 18 and the governor cap 19 has a skirt of backwardly extending cylindrical wall 20 which is internally threaded at 21 and is screwed onto the threads 18 on the front end of the body 7. Centrally the governor cap 19 has a relatively large opening 22 providing complete clearance for the discharge through the orifice 16.

The front end of the piston 15 has an axially extending annular groove 23 in which a coil compression metal spring 24 is retained with its front end engaging the inside of the cap governor 19, so that the piston 15 is always biased backwardly to a retracted position. The previously described earlier Laauwe valve has the front end of the rod and the wall surrounding the discharge orifice, formed with cooperating male and female parts which slidingly interfit in a substantially fluid-tight manner, and in the form of curved segments, thus providing a swirl chamber for the product when it is discharged through the actuators orifice.

The above advantage can also be provided for the present actuator. Thus, the male vanes or baffles are shown at 25 with the mating female grooves 26 in the end of what is in this instance the stationary rod or probe. An example is illustrated in cross section by FIG. 6. When the valve is operating, as shown by FIG. 5, circumferentially directed orifices open to direct the pressurized product into the space 27 defined within the male vanes or baffles 26, the product swirling in the space 27 before ejecting through the discharge orifice 16. This space 27 also provides a pre-expansion chamber to which the pressurized product has access through the two orifices formed by the spaces between the male vanes, these orifices being adjustable in cross sectional area by screwing the governor cap to different positions restricting forward motion of the piston varying amounts.

In FIG. 7 the metal coil spring 24 and its retaining groove are eliminated, the piston having a forwardly angled elastically flexible annulus 24a which biases the piston backwardly.

When the male and female parts 25 and 26 are contoured to provide a swirl chamber, it is necessary to prevent rotation of the piston 15, caused by rotation of the screw governor cap 19. This may be done by providing the piston with an axially extending integral key 28 which reciprocates in a keyway or groove 29 formed on the inside of the cylindrical wall 8 of the bodys cavlty.

However, if the outermost portions or skirts 26a defining the grooves 26 in the front end of the stationary rod or probe 13, are removed, and the contour of the remaining portion of the rod's front end and of the male parts 25, are made substantially symmetrical, it becomes unimportant whether or not the piston 15 can rotate, thus making the key 28 and keyway 29 unnecessary.

It can now be appreciated that this invention provides an actuator having the unusual feature of a governor for controlling the pattern and nature of the discharged product and which permits disassembly of the actuator, but with the present invention, disassembly resulting in the opening of the actuator body facing forwardly in the same direction as the user would expect the normal discharge to occur. With this advantage, this new actuator can, of course, be disassembled as shown by FIG. 3, locked positively against any discharge as shown by FIG. 2, where the cap governor 19 is screwed fully backwardly, readily put into an operative position, as shown by FIG. 4, where the governor cap has been unscrewed and which then, when the pressure is applied as shown by the arrow A, used to effect the desired discharge governed by the rotative position of the governor cap. Although not shown, this governor cap and the body of the actuator may be marked with indicia indicating the different types of sprays to be obtained at the different rotative degrees of the governor cap.

The entire actuator, excepting for the metal coil compression spring, can be made by injection molding techniques, from any of the plastic used for actuators in general and which can form the finished actuator parts as substantially rigid elements. All plastic has some slight elasticity, this permitting the piston 15 to have the backwardly extending skirt a which is illustrated. This skirt can flex radially outwardly to a slight degree assuring a good sealing of the piston within the cylindrical wall 8. This skirt 15a has the additional ad vantage of providing the piston with a substantial axial length so that it is held against any possible tilting action which might cause it to jam, while at the same time the forward wall or front end of the piston is spaced well forwardly from the opening 11, positioned adjacent to the closed back wall 9. Therefore, the piston, during the discharge of the product, remains at its forward position fixed by the governor cap, and does not have any tendency to shut and open rapidly in succession. This new actuator operates in a suitable fashion producing a steady discharge.

What is claimed is:

1. An actuator for a tubular stem through which a pressurized product is dispensed, comprising a body having a substantially cylindrical cavity with a closed end back wall and an open front end, said body having a hole opening into said cavity adjacent to said back wall and adapted to receive said stem said body having a rod projecting from said back wall towards said open front end, a piston reciprocating in said cavity and having a discharge orifice and otherwise closing said open end, said rod having a front end positioned to close said orifice when said piston moves backwardly against said rod and to open said orifice when said piston moves forwardly, spring means for biasing said piston backwardly so that the rods said front end normally closes said orifice, and adjustable governor means on the front end of said body for adjustably limiting forward movement of said piston.

2. The actuator of claim 1 in which said body has external screw threads on the outside of its front and around its said open front end and said governor means is a cap having a skirt with internal screw threads threaded on said external screw threads, said cap having an opening registered with said discharge orifice and an inside surface engagable by said piston 3. The actuator of claim 2 in which said piston has a forwardly facing annular recess and said spring means is a coil spring positioned in said recess and engaging the caps said inside surface.

4. The actuator of claim 1 in which said piston has backwardly extending vane means forming at least one transversely extending passage, and said rods said front end fitting slidably within said vane means and normally closing said passage and opening the latter when said piston moves forwardly.

5. The actuator of claim 4 in which the rods said front end has female recesses receiving said vane means with the latter then being male means.

Claims

2. The actuator of claim 1 in which said body has external screw threads on the outside of its front and around its said open front end and said governor means is a cap having a skirt with internal screw threads threaded on said external screw threads, said cap having an opening registered with said discharge orifice and an inside surface engagable by said piston.

3. The actuator of claim 2 in which said piston has a forwardly facing annular recess and said spring means is a coil spring positioned in said recess and engaging the cap''s said inside surface.

4. The actuator of claim 1 in which said piston has backwardly extending vane means forming at least one transversely extending passage, and said rod''s said front end fitting slidably within said vane means and normally closing said passage and opening the latter when said piston moves forwardly.

5. The actuator of claim 4 in which the rod''s said front end has female recesses receiving said vane means with the latter then being male means.