CA2170445A1 - High velocity foam dispensing device and dispensing package including the same - Google Patents
High velocity foam dispensing device and dispensing package including the sameInfo
- Publication number
- CA2170445A1 CA2170445A1 CA 2170445 CA2170445A CA2170445A1 CA 2170445 A1 CA2170445 A1 CA 2170445A1 CA 2170445 CA2170445 CA 2170445 CA 2170445 A CA2170445 A CA 2170445A CA 2170445 A1 CA2170445 A1 CA 2170445A1
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- valve
- cross
- flow area
- flow
- sectional
- Prior art date
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Abstract
A dispensing device (16) for dispensing a fluid compo-sition, e.g., a foaming soap composition (18) has a reduc-ed risk of flashback because it has a flow path including a valve having a valve outlet of reduced cross-sectional flow area as compared to conventional dispensers, and a discharge orifice (36) whose cross-sectional flow area does not exceed the cross-sectional flow area of the mass flow rate limiting aperture of the device by more than about 1000 percent. This enables attainment of a high but controllable discharge velocity. The device includes a capillary dip tube (28) connected in flow communication with a valve which controls the flow of the foaming soap composition through the device by movement of the valve between a closed and a fully-open position. The valve is biased towards its closed position by a threshold bias spring (27a) which accelerates movement of the valve to-wards its fully-open position upon actuation, i.e., causes the valve to snap to its fully-open position upon the ap-plication of opening pressure to the valve.
Description
HIGH VELOCITY FOAM DISPENSING DEVICE
AND DISPENSING PACKAGE INCLUDING THE SAME
~ACKGROUND OF THE INVENTION
Field of the Invention The present invention relates to an improved dispens-ing device for pressurized dispenser containers such as aerosol spray cans, and to packages which include the dis-pensing device. The improved device reduces the flamehazard of such containers, especially with respect to con-tainers pressurized with flammable propellants for dis-pensing fluid compositions.
The Consumer Product Safety Commission has banned the sale to children of pressurized, spray-type products which, when sprayed into an open flame, produce conditions deemed by the CPSC to be hazardous. One hazardous condi-tion may occur if the discharge velocity of the product is too slow, in that once the product is ignited, the flame front will advance upstream or to the discharge nozzle.
This condition is referred to as flashback. Second, if a flammable product is dispersed too forcefully, it may car-ry the flame front to a dangerous distance from the user and impinge on flammable objects or other persons. A test ~ 25 to which an aerosoI~~spray-can~may be subjected to detect these hazards is set forth at 16 CFR (Code of Federal Reg-ulations) 1500.45. Generally, the test involves placing the aerosol can package six inches from a flame source and spraying the contents through the top of the flame for periods of 15 to 20 seconds and observing the resulting flame. If flashback occurs or if flame projection exceeds 18 inches (about 45.7 centimeters,"cm") the package is considered unsafe and must be marked with appropriate warning information.
SUMMARY OF THE lN~ lON
In accordance with the present invention there is pro-vided an improvement in a dispensing device defining a flow path terminating in a discharge orifice and through which flow path a fluid composition may be dispensed from the interior of a pressurized container on which the de-vice is mounted. The device comprises mounting means to seal the device onto the container and a valve movable be-tween a closed position and a fully-open position to con-trol the flow rate of the composition through the flowpath. There is an actuator means to move the valve be-tween its closed and fully-open positions. The device de-fines an internal flow gate having a cross-sectional flow area that limits the mass flow rate of fluid composition through the device at least when the valve is in its fully open position. The improvement comprises that the dis-charge orifice has a cross-sectional flow area that does not exceed about 1000% of cross-sectional flow area of the internal flow gate. In a particular embodiment of the invention, the discharge orifice may have a cross-section-al flow area about 220% as large as that of the internal flow gate.
According to one aspect of the invention, the internal flow gate may have a cross-sectional flow area of at least - 25 about 0.13 X 10-3 square inches (about 0.845 X 10-3 cm2);
in typical embodiments the internal flow gate may have a cross-sectional flow area of from about 0.3 X 10- 3 to 2.8 X 10-3 square inches (about 1.9 X 10- 3 to 18 X 10- 3 cm2 ) .
Optionally, the discharge orifice may have a cross-sec-tional flow area of from about 0.3 X 10- 3 to 2.8 X 10- 3 square inches (about 2.0 X 10-3 to 18 X 10-3 Cm2 ) In a specific embodiment, the internal flow gate may comprise two orifices each having a cross-sectional flow area of about 0.45 X 10- 3 square inches (about 2.9 X 10- 3 cm2), and the discharge aperture may have a cross-section-al flow area of about 2 X 10- 3 square inches (about 13 X
10- 3 cm2 ) .
According to another aspect of the invention, the de-- 2 1 7 ~44~
vice may comprise a dip tube that extends into the interi-or of the container and that is connected in flow communi-cation with the valve to thereby define part of the flow path. The dip tube may have a cross-sectional flow area of from about 0.7 X 10- 3 square inches to 2.8 X 10- 3 square inches (about 4.5 X 10-3 to 18.3 X 10- 3 cm2 ) .
According to yet another aspect of the invention, the device may comprise a threshold bias spring mounted there-in to bias the valve into its closed position and to ac-celerate full opening of the valve upon commencement ofopening actuation of the valve.
According to still another aspect of the invention, the device comprises part of a dispenser package for dis-pensing a fluid composition, the package comprising a pressurized container containing the fluid composition, including a flammable propellant, with the dispensing de-vice as described above mounted on the container. The - propellant is a normally gaseous propellent which is at least partly soluble in the fluid composition. The fluid composition may comprise a foaming soap composition or a polymeric composition. A typical fluid composition may have, at 20C, a viscosity within the package of at least about 1000 centipoise, for example, in the case of a foam-ing soap composition, a viscosity of from about 2000 to 4000 centipoise, and may have, at 2-0C, a specific gravity within the package of from about 0.9 to 1.0 grams per cu-bic centimeter.
BRIEF D~S~RTPTION OF THE DRAWINGS
Figure 1 is a partly cross-sectional, schematic view of an aerosol dispenser package comprising a dispensing device in accordance with the present invention mounted on a container;
Figure 2 is a partly cross-sectional view of the dis-pensing device of Figure l;
Figure 3 is a partly cross-sectional, broken-away view of the valve of the dispensing device of Figures 1 and 2, shown on an enlarged scale relative to Figures 1 and 2;
-Figure 4 is a view similar to that of Figure 2 of a dispensing device comprising a threshold bias spring in accordance with a particular embodiment of the invention;
and Figures 5A is a schematic cross-sectional view, on an enlarged scale, of the threshold bias spring of the device of Figure 4;
Figure 5B is a graph showing typical deflection curves for threshold bias springs of the type shown in Figure 5A;
and Figure 5C is a schematic cross-sectional view of a plurality of springs as shown in Figures 5A stacked upon each other to increase total potential deflection.
DETAILED DR~rRTPTION OF T~E lNv~ loN
AND PREFERRED EMBODIMENTS ~K~OF
The present invention relates to a dispensing device which, when used to dispense a fluid composition from a pressurized container, is safer with respect to flame hazards than those of the prior art. The dispensing de-vice of the present invention inhibits flashback by as-suring an adequate exit velocity for the dispensed pro-duct, i.e., an exit velocity that exceeds the velocity at which a flame propagates upstream through dispensed pro-duct towards the user. This is accomplished by providingthe dispensing device with a discharge orifice which has a proportionately smaller cross-sectional flow area than those of conventional dispensing devices for pressurized fluid compositions, relative to the mass flow rate-limit-ing internal orifices (collectively referred to herein asthe "internal flow gate") of the device. The dispensed fluid composition may provide, e.g~, a foaming soap pro-duct or a polymeric "string" product, the latter compris-ing a fluid polymeric composition which, when exposed to air upon expulsion in a continuous stream from a pressur-ized container, congeals into a malleable string-like solid. One such string product is sold under the trade designation "Silly String".
The most common foaming soap product is shaving cream, which is dispensed through conventional dispensing devices at a slow exit velocity to yield an oozing mass that the user can easily deposit in the palm of a hand placed di-rectly beneath the discharge orifice. For this purpose,the cross-sectional flow area of the discharge orifice of the conventional dispensing device is substantially larger than that of the internal flow gate of the dispensing de-vice, which precedes the discharge orifice (with respect to the flow of the soap composition therethrough) and which limits the mass flow rate of the soap composition through the device. Accordingly, when the composition - reaches the discharge orifice it slows considerably rela-tive to its velocity through the internal flow gate. In a conventional aerosol-dispensing assembly for shaving cream, the discharge orifice is defined by an actuator that engages a conventional stem valve. The stem valve has a hollow stem having an outlet from which the soap composition leaves the valve and, typically, a pair of valve inlet apertures through which the composition flows to the interior of the stem. The combined cross-sectional flow areas of the valve inlet apertures limit the mass flow rate of the soap composition through the dispensing apparatus at least when the valve is in its fully open - - 25 position, and are collectively referred to herein as the internal flow gate of the device. In a typical configura-tion, the two round valve inlet apertures may have diame-ters of about 0.024 inches ("in.") (0.61 millimeters, "mm"), providing a combined cross-sectional flow area of about 0.9 X 10 3 in2 (5.8 X 10- 3 cm 2 ) . A conventional actuator for a shaving cream can has a discharge orifice with a rectangular cross-sectional configuration measuring about 0.125 inches (.317 cm) in width and 0.188 inches (.477 cm) in length, resulting in a typical cross-section-al flow area of 23.5 X 10-3 square inches (151 X 10-3 cm2 ) which is about 26 times (2600%) larger than the total cross-sectional flow area of the internal flow gate. As a result of having an over-sized discharge orifice, the exit - 21 704~5 velocity of the product is slowed to such a degree that flashback may occur. Further, the rectangular configura-tion produces a poor streaming characteristic since it disperses the product in a wide spray pattern, which in-creases the opportunity for flashback to occur.
The present invention provides an aerosol-dispensing device which has a discharge orifice that is dimensioned and configured so that the exit velocity of flammable pro-pellant vapor, for example, vapor from liquified propel-lant gasses such as isobutane, n-butane propane, difluoro-ethane, dimethyloxide, etc. and mixtures thereof, is suf-ficently high to prevent flashback. This is achieved, at least in part, by providing the dispenser with a discharge orifice that has a cross-sectional flow area that does not exceed the cross-sectional flow area of the internal flow gate of the device by more than about 1000 percent. Pre-ferably, the discharge orifice is round in cross-sectional configuration since this provides the spray pattern that best resists flashback. Some variation in the maximum allowable ratio of cross-sectional flow areas of the dis-charge orifice and the internal flow gate may be permis-sible to account for differences in soap composition vis-cosity or other product characteristics, but such minor variations can easily be determined by one skilled in the art in view of the speeific examples and teachings of the present disclosure.
Stem valves useful in dispensing soap compositions ac-cording to the present invention typically have one to four circular internal valve inlet apertures having diame-ters of at least about 0.013 inches (0.43 mm), more typi-cally from 0.016 to 0.03 inches (0.41 to 0.76 mm). The valve inlet apertures are usually the smallest apertures in the dispensing device and therefore limit the mass flow rate of the soap composition through the dispensing de-vice. In such case, they constitute the internal flowgate of the device. Accordingly, the cross-sectional flow area of the internal flow gate of the device is typically at least about 0.13 X 10-3 in2 (about 0.84 X 10- 3 cm2) and may range from about 0.2 X 10- 3 square inches (as may be provided by a single valve inlet aperture of diameter 0.016 inches (0.41mm)) to 2.8 X 10-3 square inches (about 1.29 x 10-3 to 18.1 X 10-3 cm2) (as may be provided by four valve inlet apertures each having a diameter of 0.03 inches (0.76 mm)). In other embodiments of dispensing de-vices according to the present invention, the internal flow gate may be defined by other apertures in the device, e.g., the valve housing, the stem outlet, etc. In any event, a dispenser device according to the present inven-tion has a discharge orifice having a cross-sectional flow area of not more than about ten times that of the internal flow qate. For example, a device defining an internal flow gate having a cross-sectional flow area of 0.9 x 10- 3 square inches (5.8 X 10 3 cm2 ) ~ as may be provided by a pair of circular valve inlet apertures each having a di-ameter of 0.024 inches (0.61 cm), may comprise a discharge orifice having a cross-sectional flow area of not more than about 9 X 10-3 in2 (about 58 X 10-3 cm2 ) . For a cir-cular discharge orifice, this corresponds to a diameter ofnot more than about 0.107 inches (about 2.7 mm). More typically, the discharge orifice will have a diameter in the range of from about 0.02 to 0.06 inches (about 0.51 to 1.5 mm) providing a cross-sectional flow area of from about 0.3 to 2.8 X 10- 3 square inches (about 2 X 10- 3 to-18 1 X 10-3 Cm2) Another aspect of the invention relates to the reali-zation that for products dispensed from an aerosol-dis-pensing device that comprises a dip tube, there is an in-creased risk of flashback if the aerosol package has beenstanding for a significant period of time between uses.
The reason for this is that when the composition is allow-ed to stand, propellant emulsified therein tends to rise, creating a top layer comprising a high concentration of propellant. In the main portion of the container, propel-lant in the top layer of the composition may be re-dis-persed throughout the composition by shaking the can, but shaking is not effective to re-disperse the composition in the dip tube. Therefore, when the user next opens the valve, the initial discharge from the container comprises a flammable, propellant-rich layer of fluid which is high-ly flammable and may exhibit flashback should contact be made with an open flame. To reduce this hazard, the pre-sent invention provides that the foaming soap composition is delivered through a capillary style dip tube, i.e., a dip tube having an internal cross-sectional flow area which is smaller than that of conventional dip tubes used for dispensing foaming soap compositions. Conventional dip tubes have circular internal cross-sectional flow areas having internal diameters of from about 0.1 inches to 0.2 inches (about 2.4 to 5 mm), which provide from about 7.8 X 10-3 to 31.4 X 10-3 square inches (about 50.3 X 10-3 cm2 to 203 X 10-3 cm2 ) of cross-sectional flow area. A capillary dip tube in accordance with the present invention has a cross-sectional flow area of 0.7 X 10- 3 to 2.83 X 10- 3 square inches (about 4.6 X 10- 3 to 18.3 X 10- 3 cm2), corresponding to a circular cross-sectional flow area having a diameter of from about 0.03 to 0.06 inches (about 1.0 to 1.5 mm), and may therefore define the inter-nal flow gate of the device. By providing a capillary dip tube, the head space volume where educted propellant vapor or propellant-rich fluid may accumulate is reduced, thus reducing the quantity of-flammable material that can be emitted and the associated flamability hazard as compared to stAn~Ard dip tubes. The re-dispersed composition that follows the flammable top layer is not flammable, due to the presence of non-flammable soap constituents in the product stream.
The valve of an aerosol-dispensing device according to the present invention is movable between a closed position in which flow is prevented and, through a range of par-tially-open positions, to a fully-open position in which flow through the dispensing device is permitted, the flow rate increasing to its maximum as the valve approaches the fully open position. A spring biases the valve towards its closed position and, in accordance with an embodiment 2 1 70~45 of the present invention, the spring has a threshold bias characteristic, i.e., it offers maximum resistance against the initial opening motion of the valve and reduced re-sistance thereafter. The threshold bias spring facili-tates full opening of the valve since the force requiredto move the valve from the closed position to an initial, partially open position is greater than the force required to move the valve further to a fully-open position. Thus, the force required to initially open the valve is a thres-hold force which, when applied consistently, will tend toaccelerate movement of the valve to its fully-open posi-tion, that is, to snap the valve fully open. This helps to prevent flashbacks because the valve is moved extremely rapidly through its partially-open position to its fully-open position and the product is dispensed at a higher ve-locity when the valve is fully open than when it is par-tially open.
There is shown in Figure 1 an aerosol product package 10 which comprises a generally cylindrical aerosol con-tainer 12 having a closed bottom 14 and an open top sealedby dispensing device 16 to secure therein a fluid soap composition 18 which is pressurized under a charge of gas-eous flammable propellant 20. In a foaming soap composi-tion, the propellant is typically liquifiable and, in li-quid form, constitutes part of the soap composition. Whendischarged from the package, the propellant in the soap composition quickly vaporizes in the dispensed product, causing it to foam.
Dispensing device 16 comprises a mounting cup 22 that sealingly engages the open end of can 12, a valve housing 24 which is crimped in sealing engagement with mounting cup 22 and within which is disposed a valve, of which only the hollow stem 26 is visible in Figure 1. Mounting cup 22 comprises a crimp ring 23 by which dispensing device 16 is sealed onto the can. The valve is movable between a closed position and, through a range of partially-open positions, a fully-open position, and is biased towards the closed position by a spring 27. A dip tube 28 is se---1 o--cured to the inlet of the housing 24 and extends towardsthe bottom of can 12 to provide a conduit to deliver li-quid foaminq soap composition 18 to the valve under pres-sure provided by the pressurized propellant 20. Dispens-ing device 16 further comprises an actuator device 30which engages stem 26 of the valve and which defines a flow path from the valve outlet to the actuator outlet, from which product 18 is expelled.
Dispensing device 16 comprises a displaceable member 32 which has a generally T-shaped configuration, an up-right portion 31, and a crossbar portion 33 which defines a conduit 34 therethrough. The base of the upright por-tion 31 of displaceable member 32 engages the outlet of stem 26, and conduit 34 extends through upright portion 31 to crossbar portion 33, and then along crossbar portion 33 to one end thereof, where conduit 34 ends with discharge orifice 36. Thus, displaceable member 32 defines the por-tion of the flow path through dispensing device 16 down-stream of stem 26.
Displaceable member 32 is flexibly connected to cap 38 by a linking arm 40 which has two ends, one of which is attached to the end of crossbar portion 33 opposite dis-charge orifice 36, and the other which is flexibly attach-ed to cap 38 at hinge area 42. Cap 38 is dimensioned and - 25 configured to engage an upwardly extending ridge formed in - mounting cap 22 in order to secure displaceable member 32 in engagement with stem 26.
Actuator device 30 further comprises a lever member 44 which is hingeably secured to cap 38 and which engages displaceable member 32. Lever member 44 comprises a trig-ger 46 on which is mounted a bight portion 48 which engag-es crossbar portion 33 of displaceable member 32. Trigger 46 is attached to the end of each of a pair of support members, one of which, support member 50, is shown in Fig-ure 1. At the opposite ends, each support member compris-es a pair of resilient detents such as detents 52a, 52b which are dimensioned and confiqured to be insertable into a slot in cap 38 and, following insertion, to pivotably retain lever member 44 therein. The user may then grasp container 10 and conveniently dispose an index finger on trigger 46. By squeezing trigger 46, lever member 44 will pivot slightly downward, causing bight portion 48 to bear on the crossbar 33 of displaceable member 32, which pivots likewise about hinge area 42, and thus actuates stem 26, opening the valve as indicated in Figure 2.
Figures 2 and 3 provide additional details regarding configuration of the valve, indicated at 35. As shown in Figure 2, stem 26 passes through a gasket 54 to the in-terior of housing 24 where stem 26 is attached to a base 56. Spring 27 bears against an internal shoulder in hous-ing 24 and against base 56 to bias base 56 into a closed position in which it forms a seal with housing 24 and thus prevents the flow of product through the flow path. How-ever, as shown in Figure 2, the user can actuate stem 26 against the force of the spring, and thus displace base 56 into one of a number of open positions in which the seal between base 56 and housing 24 is broken. The soap compo-sition is then free to flow up dip tube 28 into the inte-rior of housing 24, through and around spring 27, around base 56 and into stem 26 via two valve apertures 58 (Fig-ure 3) which, as stated above, have a combined cross-sec-tional flow area of at least about 0.4 X 10- 3 square inches (about 2.6 X 10 3 cm2 ) ~ which constitutes the internal flow gate of the device. When the valve is fully open, base 56 is at its maximum clearance from housing 24 and maximum flow is permitted; at partially open positions, base 56 clears housing 24 to a lesser degree, and lesser rates of flow occur. When the user releases pressure from trigger 46, spring 27 forces base 56 back into the closed position in which it forms a seal with housing 24, thus preventing propellant and soap com-position from entering valve apertures 58.
Dispensing device 16 defines a flow path which, in the embodiment illustrated in Figures 1, 2 and 3, includes the interior of dip tube 28, the interior of housing 24, valve apertures 58, the interior of stem 26 and conduit 34 of displaceable member 32. Discharge orifice 36 is dimen-sioned and configured to have a circular cross-sectional flow area that does not exceed the cross-sectional flow area of the internal flow gate by more than a factor of 10. In order to adapt a conventional dispensing device for use with the present invention, one may position a flow path-narrowing insert 60 in the oversized outlet, as shown in Figure 1. Insert 60 is secured within the ori-fice and has an internal passage that provides a reduced discharge orifice in accordance with the present inven-tion.
To ameliorate the flammability problem of the propel-lant-rich top layer of fluid that can accumulate in the dip tube between uses, the aerosol product container 10 in accordance with the present invention comprises a dip tube 28 having a reduced internal volume. Specifically, dip tube 28 is a capillary style dip tube having an internal diameter in the range of about 0.03 to 0.06 inches (about 0.75 to 1.5 mm).
The combination of a capillary dip tube with a foaming soap product also reduces flammability risks when the valve is actuated with the can in an upside-down position.
Ordinarily, flame hazards are exaggerated in the upside-down position since the liquid composition falls away from the opening of the dip tube, allowing the propellant vapor to flow un-impeded through the valve assembly. However, the capillary dip tube of the present invention collects a smaller quantity of propellant therein, and discharge of propellant causes the foaming soap composition to bubble up inside the can and quickly reach the opening of dip tube 28. Accordingly, even in the upside-down position, aerosol product package 10 can emit educted propellant vapor only for a very short period of time, during which the exit velocity and spray pattern will be adequate to prevent flashback.
To further reduce flashback, the dispensing device may comprise a threshold bias spring rather than a conven-tional bias spring. The resistance offered by a conven-tional spring increases as the spring is compressed, thus resisting full actuation of the valve. In contrast, threshold bias spring 27a (Figure 4) which is a spring washer, is characterized in that the force needed to ini-tially open the valve is close to that required for fur-ther movement to its fully-open position. Therefore, if the user applies constant force sufficient to actuate the valve, the valve will tend to snap open, fully exposing valve apertures 58 to the interior of housing 24, and the user will be less likely to inadvertently depress the valve only part way. Full actuation of the valve ensures that the product will be dispensed at maximum exit veloci-ty, thus reducing the risk of flashback. Such springs are commercially available under the trade designation Belle-ville Spring Washers. Threshold bias spring 27a is shownin an enlarged scale in Figure 5A, in which the thickness t, the spring height H and the associated nominal dish or core dimension h of the spring are indicated.
The height H is the perpendicular distance from the base plane of the spring, i.e., from the plane on which the spring can rest on its outer peripheral edge, to the top plane of the spring, i.e., the plane of the inner peripheral edge of the spring, parallel to the base plane, in which a load can contact the spring without causing deflection. By subtracting the thickness t from height H, the cone dimension h is derived. The proportion of h to t can be used to characterize the deflection characteristics of the spring. For example, the graph of Figure 5B shows three deflection curves for springs in which h = t, h =
0.5 t and h = 0.25 t. In the graph, the applied load is given as a percentage of the minimum load that will cause full deflection ("full deflection load"), and is shown on the ordinate, whereas the resulting deflection is shown on the abscissa as a percentage of full deflection (in which the spring is flattened). The graph shows, for example, that for a spring in which h = t, the initial 50% of full deflection requires 70% of full deflection load; the re-maining 50% deflection is attained by adding only 30% of the full deflection load. If the full deflection of a single spring washer does not provide adequate valve actu-ation, the springs can be stacked as shown in Figure SC
without defeating the threshold bias characteristic of the valve.
A typical foaming soap composition for use with the present invention comprises 26.3% water, 13.74% disodium cocoamphodiacetate, 13.74% low viscosity disodium cocoam-phodiacetate, 27.48% TEA lauryl sulfate, 0.56% lauramide DEA, 0.1% methyl paraben, 1% polysorbate 20, 0.5% fra-grance, 0.2% hydroxyethylcellulose, and 17% isobutane as the propellant. The composition has a specific gravity of 0.92 grams per milliliter (including the isobutane propel-lant) and a viscosity of 3000 cps. In addition, the re-sulting product is advantageously amphoteric, and so willnot cause any burning sensation should the user inadvert-ently get soap in his or her eyes. A charge of the fore-going soap composition was disposed in an aerosol contain-er sealed with a dispensing device in which the valve had two circular valve inlet apertures, each having a diameter of 0.024 inches (0.61 mm) defining a combined cross-sec-tional flow area of 0.9 X 10- 3 square inches (5.8 X 10- 3 cm2) and a housing to which a capillary dip tube having an internal diameter of 0.04 inches (1 mm) giving a cross-sectional flow area of 1.26 X 10-3 in2 (8.1 x 10-3 cm2 ) was attached. A button-style actuator having an iris spout defining a discharge orifice having a circular con-figuration with a diameter of 0.05 inches (1.27 mm) was secured on the valve. The cross-sectional flow area of the discharge orifice was accordingly 1.96 X 10- 3 square inches (12.7 X 10-3 cm2 ). Therefore, the ratio of the cross-sectional flow area of the discharge orifice to that of the valve inlet apertures was only 2.18:1, i.e., the discharge orifice was only about 220% larger than the in-ternal flow gate. The aerosol dispenser described abovewas tested for flame hazard safety by spraying the product through a flame with the container in both an upright and an upside-down position. The flame front did not exceed -18 inches and did not flash back to the dispenser.
While the invention has been described in detail with respect to specific embodiments thereof, it is to be un-derstood that upon a reading of the foregoing description,variations to the specific embodiments disclosed may occur to those skilled in the art and it is intended to include such variations within the scope of the appended claims.
AND DISPENSING PACKAGE INCLUDING THE SAME
~ACKGROUND OF THE INVENTION
Field of the Invention The present invention relates to an improved dispens-ing device for pressurized dispenser containers such as aerosol spray cans, and to packages which include the dis-pensing device. The improved device reduces the flamehazard of such containers, especially with respect to con-tainers pressurized with flammable propellants for dis-pensing fluid compositions.
The Consumer Product Safety Commission has banned the sale to children of pressurized, spray-type products which, when sprayed into an open flame, produce conditions deemed by the CPSC to be hazardous. One hazardous condi-tion may occur if the discharge velocity of the product is too slow, in that once the product is ignited, the flame front will advance upstream or to the discharge nozzle.
This condition is referred to as flashback. Second, if a flammable product is dispersed too forcefully, it may car-ry the flame front to a dangerous distance from the user and impinge on flammable objects or other persons. A test ~ 25 to which an aerosoI~~spray-can~may be subjected to detect these hazards is set forth at 16 CFR (Code of Federal Reg-ulations) 1500.45. Generally, the test involves placing the aerosol can package six inches from a flame source and spraying the contents through the top of the flame for periods of 15 to 20 seconds and observing the resulting flame. If flashback occurs or if flame projection exceeds 18 inches (about 45.7 centimeters,"cm") the package is considered unsafe and must be marked with appropriate warning information.
SUMMARY OF THE lN~ lON
In accordance with the present invention there is pro-vided an improvement in a dispensing device defining a flow path terminating in a discharge orifice and through which flow path a fluid composition may be dispensed from the interior of a pressurized container on which the de-vice is mounted. The device comprises mounting means to seal the device onto the container and a valve movable be-tween a closed position and a fully-open position to con-trol the flow rate of the composition through the flowpath. There is an actuator means to move the valve be-tween its closed and fully-open positions. The device de-fines an internal flow gate having a cross-sectional flow area that limits the mass flow rate of fluid composition through the device at least when the valve is in its fully open position. The improvement comprises that the dis-charge orifice has a cross-sectional flow area that does not exceed about 1000% of cross-sectional flow area of the internal flow gate. In a particular embodiment of the invention, the discharge orifice may have a cross-section-al flow area about 220% as large as that of the internal flow gate.
According to one aspect of the invention, the internal flow gate may have a cross-sectional flow area of at least - 25 about 0.13 X 10-3 square inches (about 0.845 X 10-3 cm2);
in typical embodiments the internal flow gate may have a cross-sectional flow area of from about 0.3 X 10- 3 to 2.8 X 10-3 square inches (about 1.9 X 10- 3 to 18 X 10- 3 cm2 ) .
Optionally, the discharge orifice may have a cross-sec-tional flow area of from about 0.3 X 10- 3 to 2.8 X 10- 3 square inches (about 2.0 X 10-3 to 18 X 10-3 Cm2 ) In a specific embodiment, the internal flow gate may comprise two orifices each having a cross-sectional flow area of about 0.45 X 10- 3 square inches (about 2.9 X 10- 3 cm2), and the discharge aperture may have a cross-section-al flow area of about 2 X 10- 3 square inches (about 13 X
10- 3 cm2 ) .
According to another aspect of the invention, the de-- 2 1 7 ~44~
vice may comprise a dip tube that extends into the interi-or of the container and that is connected in flow communi-cation with the valve to thereby define part of the flow path. The dip tube may have a cross-sectional flow area of from about 0.7 X 10- 3 square inches to 2.8 X 10- 3 square inches (about 4.5 X 10-3 to 18.3 X 10- 3 cm2 ) .
According to yet another aspect of the invention, the device may comprise a threshold bias spring mounted there-in to bias the valve into its closed position and to ac-celerate full opening of the valve upon commencement ofopening actuation of the valve.
According to still another aspect of the invention, the device comprises part of a dispenser package for dis-pensing a fluid composition, the package comprising a pressurized container containing the fluid composition, including a flammable propellant, with the dispensing de-vice as described above mounted on the container. The - propellant is a normally gaseous propellent which is at least partly soluble in the fluid composition. The fluid composition may comprise a foaming soap composition or a polymeric composition. A typical fluid composition may have, at 20C, a viscosity within the package of at least about 1000 centipoise, for example, in the case of a foam-ing soap composition, a viscosity of from about 2000 to 4000 centipoise, and may have, at 2-0C, a specific gravity within the package of from about 0.9 to 1.0 grams per cu-bic centimeter.
BRIEF D~S~RTPTION OF THE DRAWINGS
Figure 1 is a partly cross-sectional, schematic view of an aerosol dispenser package comprising a dispensing device in accordance with the present invention mounted on a container;
Figure 2 is a partly cross-sectional view of the dis-pensing device of Figure l;
Figure 3 is a partly cross-sectional, broken-away view of the valve of the dispensing device of Figures 1 and 2, shown on an enlarged scale relative to Figures 1 and 2;
-Figure 4 is a view similar to that of Figure 2 of a dispensing device comprising a threshold bias spring in accordance with a particular embodiment of the invention;
and Figures 5A is a schematic cross-sectional view, on an enlarged scale, of the threshold bias spring of the device of Figure 4;
Figure 5B is a graph showing typical deflection curves for threshold bias springs of the type shown in Figure 5A;
and Figure 5C is a schematic cross-sectional view of a plurality of springs as shown in Figures 5A stacked upon each other to increase total potential deflection.
DETAILED DR~rRTPTION OF T~E lNv~ loN
AND PREFERRED EMBODIMENTS ~K~OF
The present invention relates to a dispensing device which, when used to dispense a fluid composition from a pressurized container, is safer with respect to flame hazards than those of the prior art. The dispensing de-vice of the present invention inhibits flashback by as-suring an adequate exit velocity for the dispensed pro-duct, i.e., an exit velocity that exceeds the velocity at which a flame propagates upstream through dispensed pro-duct towards the user. This is accomplished by providingthe dispensing device with a discharge orifice which has a proportionately smaller cross-sectional flow area than those of conventional dispensing devices for pressurized fluid compositions, relative to the mass flow rate-limit-ing internal orifices (collectively referred to herein asthe "internal flow gate") of the device. The dispensed fluid composition may provide, e.g~, a foaming soap pro-duct or a polymeric "string" product, the latter compris-ing a fluid polymeric composition which, when exposed to air upon expulsion in a continuous stream from a pressur-ized container, congeals into a malleable string-like solid. One such string product is sold under the trade designation "Silly String".
The most common foaming soap product is shaving cream, which is dispensed through conventional dispensing devices at a slow exit velocity to yield an oozing mass that the user can easily deposit in the palm of a hand placed di-rectly beneath the discharge orifice. For this purpose,the cross-sectional flow area of the discharge orifice of the conventional dispensing device is substantially larger than that of the internal flow gate of the dispensing de-vice, which precedes the discharge orifice (with respect to the flow of the soap composition therethrough) and which limits the mass flow rate of the soap composition through the device. Accordingly, when the composition - reaches the discharge orifice it slows considerably rela-tive to its velocity through the internal flow gate. In a conventional aerosol-dispensing assembly for shaving cream, the discharge orifice is defined by an actuator that engages a conventional stem valve. The stem valve has a hollow stem having an outlet from which the soap composition leaves the valve and, typically, a pair of valve inlet apertures through which the composition flows to the interior of the stem. The combined cross-sectional flow areas of the valve inlet apertures limit the mass flow rate of the soap composition through the dispensing apparatus at least when the valve is in its fully open - - 25 position, and are collectively referred to herein as the internal flow gate of the device. In a typical configura-tion, the two round valve inlet apertures may have diame-ters of about 0.024 inches ("in.") (0.61 millimeters, "mm"), providing a combined cross-sectional flow area of about 0.9 X 10 3 in2 (5.8 X 10- 3 cm 2 ) . A conventional actuator for a shaving cream can has a discharge orifice with a rectangular cross-sectional configuration measuring about 0.125 inches (.317 cm) in width and 0.188 inches (.477 cm) in length, resulting in a typical cross-section-al flow area of 23.5 X 10-3 square inches (151 X 10-3 cm2 ) which is about 26 times (2600%) larger than the total cross-sectional flow area of the internal flow gate. As a result of having an over-sized discharge orifice, the exit - 21 704~5 velocity of the product is slowed to such a degree that flashback may occur. Further, the rectangular configura-tion produces a poor streaming characteristic since it disperses the product in a wide spray pattern, which in-creases the opportunity for flashback to occur.
The present invention provides an aerosol-dispensing device which has a discharge orifice that is dimensioned and configured so that the exit velocity of flammable pro-pellant vapor, for example, vapor from liquified propel-lant gasses such as isobutane, n-butane propane, difluoro-ethane, dimethyloxide, etc. and mixtures thereof, is suf-ficently high to prevent flashback. This is achieved, at least in part, by providing the dispenser with a discharge orifice that has a cross-sectional flow area that does not exceed the cross-sectional flow area of the internal flow gate of the device by more than about 1000 percent. Pre-ferably, the discharge orifice is round in cross-sectional configuration since this provides the spray pattern that best resists flashback. Some variation in the maximum allowable ratio of cross-sectional flow areas of the dis-charge orifice and the internal flow gate may be permis-sible to account for differences in soap composition vis-cosity or other product characteristics, but such minor variations can easily be determined by one skilled in the art in view of the speeific examples and teachings of the present disclosure.
Stem valves useful in dispensing soap compositions ac-cording to the present invention typically have one to four circular internal valve inlet apertures having diame-ters of at least about 0.013 inches (0.43 mm), more typi-cally from 0.016 to 0.03 inches (0.41 to 0.76 mm). The valve inlet apertures are usually the smallest apertures in the dispensing device and therefore limit the mass flow rate of the soap composition through the dispensing de-vice. In such case, they constitute the internal flowgate of the device. Accordingly, the cross-sectional flow area of the internal flow gate of the device is typically at least about 0.13 X 10-3 in2 (about 0.84 X 10- 3 cm2) and may range from about 0.2 X 10- 3 square inches (as may be provided by a single valve inlet aperture of diameter 0.016 inches (0.41mm)) to 2.8 X 10-3 square inches (about 1.29 x 10-3 to 18.1 X 10-3 cm2) (as may be provided by four valve inlet apertures each having a diameter of 0.03 inches (0.76 mm)). In other embodiments of dispensing de-vices according to the present invention, the internal flow gate may be defined by other apertures in the device, e.g., the valve housing, the stem outlet, etc. In any event, a dispenser device according to the present inven-tion has a discharge orifice having a cross-sectional flow area of not more than about ten times that of the internal flow qate. For example, a device defining an internal flow gate having a cross-sectional flow area of 0.9 x 10- 3 square inches (5.8 X 10 3 cm2 ) ~ as may be provided by a pair of circular valve inlet apertures each having a di-ameter of 0.024 inches (0.61 cm), may comprise a discharge orifice having a cross-sectional flow area of not more than about 9 X 10-3 in2 (about 58 X 10-3 cm2 ) . For a cir-cular discharge orifice, this corresponds to a diameter ofnot more than about 0.107 inches (about 2.7 mm). More typically, the discharge orifice will have a diameter in the range of from about 0.02 to 0.06 inches (about 0.51 to 1.5 mm) providing a cross-sectional flow area of from about 0.3 to 2.8 X 10- 3 square inches (about 2 X 10- 3 to-18 1 X 10-3 Cm2) Another aspect of the invention relates to the reali-zation that for products dispensed from an aerosol-dis-pensing device that comprises a dip tube, there is an in-creased risk of flashback if the aerosol package has beenstanding for a significant period of time between uses.
The reason for this is that when the composition is allow-ed to stand, propellant emulsified therein tends to rise, creating a top layer comprising a high concentration of propellant. In the main portion of the container, propel-lant in the top layer of the composition may be re-dis-persed throughout the composition by shaking the can, but shaking is not effective to re-disperse the composition in the dip tube. Therefore, when the user next opens the valve, the initial discharge from the container comprises a flammable, propellant-rich layer of fluid which is high-ly flammable and may exhibit flashback should contact be made with an open flame. To reduce this hazard, the pre-sent invention provides that the foaming soap composition is delivered through a capillary style dip tube, i.e., a dip tube having an internal cross-sectional flow area which is smaller than that of conventional dip tubes used for dispensing foaming soap compositions. Conventional dip tubes have circular internal cross-sectional flow areas having internal diameters of from about 0.1 inches to 0.2 inches (about 2.4 to 5 mm), which provide from about 7.8 X 10-3 to 31.4 X 10-3 square inches (about 50.3 X 10-3 cm2 to 203 X 10-3 cm2 ) of cross-sectional flow area. A capillary dip tube in accordance with the present invention has a cross-sectional flow area of 0.7 X 10- 3 to 2.83 X 10- 3 square inches (about 4.6 X 10- 3 to 18.3 X 10- 3 cm2), corresponding to a circular cross-sectional flow area having a diameter of from about 0.03 to 0.06 inches (about 1.0 to 1.5 mm), and may therefore define the inter-nal flow gate of the device. By providing a capillary dip tube, the head space volume where educted propellant vapor or propellant-rich fluid may accumulate is reduced, thus reducing the quantity of-flammable material that can be emitted and the associated flamability hazard as compared to stAn~Ard dip tubes. The re-dispersed composition that follows the flammable top layer is not flammable, due to the presence of non-flammable soap constituents in the product stream.
The valve of an aerosol-dispensing device according to the present invention is movable between a closed position in which flow is prevented and, through a range of par-tially-open positions, to a fully-open position in which flow through the dispensing device is permitted, the flow rate increasing to its maximum as the valve approaches the fully open position. A spring biases the valve towards its closed position and, in accordance with an embodiment 2 1 70~45 of the present invention, the spring has a threshold bias characteristic, i.e., it offers maximum resistance against the initial opening motion of the valve and reduced re-sistance thereafter. The threshold bias spring facili-tates full opening of the valve since the force requiredto move the valve from the closed position to an initial, partially open position is greater than the force required to move the valve further to a fully-open position. Thus, the force required to initially open the valve is a thres-hold force which, when applied consistently, will tend toaccelerate movement of the valve to its fully-open posi-tion, that is, to snap the valve fully open. This helps to prevent flashbacks because the valve is moved extremely rapidly through its partially-open position to its fully-open position and the product is dispensed at a higher ve-locity when the valve is fully open than when it is par-tially open.
There is shown in Figure 1 an aerosol product package 10 which comprises a generally cylindrical aerosol con-tainer 12 having a closed bottom 14 and an open top sealedby dispensing device 16 to secure therein a fluid soap composition 18 which is pressurized under a charge of gas-eous flammable propellant 20. In a foaming soap composi-tion, the propellant is typically liquifiable and, in li-quid form, constitutes part of the soap composition. Whendischarged from the package, the propellant in the soap composition quickly vaporizes in the dispensed product, causing it to foam.
Dispensing device 16 comprises a mounting cup 22 that sealingly engages the open end of can 12, a valve housing 24 which is crimped in sealing engagement with mounting cup 22 and within which is disposed a valve, of which only the hollow stem 26 is visible in Figure 1. Mounting cup 22 comprises a crimp ring 23 by which dispensing device 16 is sealed onto the can. The valve is movable between a closed position and, through a range of partially-open positions, a fully-open position, and is biased towards the closed position by a spring 27. A dip tube 28 is se---1 o--cured to the inlet of the housing 24 and extends towardsthe bottom of can 12 to provide a conduit to deliver li-quid foaminq soap composition 18 to the valve under pres-sure provided by the pressurized propellant 20. Dispens-ing device 16 further comprises an actuator device 30which engages stem 26 of the valve and which defines a flow path from the valve outlet to the actuator outlet, from which product 18 is expelled.
Dispensing device 16 comprises a displaceable member 32 which has a generally T-shaped configuration, an up-right portion 31, and a crossbar portion 33 which defines a conduit 34 therethrough. The base of the upright por-tion 31 of displaceable member 32 engages the outlet of stem 26, and conduit 34 extends through upright portion 31 to crossbar portion 33, and then along crossbar portion 33 to one end thereof, where conduit 34 ends with discharge orifice 36. Thus, displaceable member 32 defines the por-tion of the flow path through dispensing device 16 down-stream of stem 26.
Displaceable member 32 is flexibly connected to cap 38 by a linking arm 40 which has two ends, one of which is attached to the end of crossbar portion 33 opposite dis-charge orifice 36, and the other which is flexibly attach-ed to cap 38 at hinge area 42. Cap 38 is dimensioned and - 25 configured to engage an upwardly extending ridge formed in - mounting cap 22 in order to secure displaceable member 32 in engagement with stem 26.
Actuator device 30 further comprises a lever member 44 which is hingeably secured to cap 38 and which engages displaceable member 32. Lever member 44 comprises a trig-ger 46 on which is mounted a bight portion 48 which engag-es crossbar portion 33 of displaceable member 32. Trigger 46 is attached to the end of each of a pair of support members, one of which, support member 50, is shown in Fig-ure 1. At the opposite ends, each support member compris-es a pair of resilient detents such as detents 52a, 52b which are dimensioned and confiqured to be insertable into a slot in cap 38 and, following insertion, to pivotably retain lever member 44 therein. The user may then grasp container 10 and conveniently dispose an index finger on trigger 46. By squeezing trigger 46, lever member 44 will pivot slightly downward, causing bight portion 48 to bear on the crossbar 33 of displaceable member 32, which pivots likewise about hinge area 42, and thus actuates stem 26, opening the valve as indicated in Figure 2.
Figures 2 and 3 provide additional details regarding configuration of the valve, indicated at 35. As shown in Figure 2, stem 26 passes through a gasket 54 to the in-terior of housing 24 where stem 26 is attached to a base 56. Spring 27 bears against an internal shoulder in hous-ing 24 and against base 56 to bias base 56 into a closed position in which it forms a seal with housing 24 and thus prevents the flow of product through the flow path. How-ever, as shown in Figure 2, the user can actuate stem 26 against the force of the spring, and thus displace base 56 into one of a number of open positions in which the seal between base 56 and housing 24 is broken. The soap compo-sition is then free to flow up dip tube 28 into the inte-rior of housing 24, through and around spring 27, around base 56 and into stem 26 via two valve apertures 58 (Fig-ure 3) which, as stated above, have a combined cross-sec-tional flow area of at least about 0.4 X 10- 3 square inches (about 2.6 X 10 3 cm2 ) ~ which constitutes the internal flow gate of the device. When the valve is fully open, base 56 is at its maximum clearance from housing 24 and maximum flow is permitted; at partially open positions, base 56 clears housing 24 to a lesser degree, and lesser rates of flow occur. When the user releases pressure from trigger 46, spring 27 forces base 56 back into the closed position in which it forms a seal with housing 24, thus preventing propellant and soap com-position from entering valve apertures 58.
Dispensing device 16 defines a flow path which, in the embodiment illustrated in Figures 1, 2 and 3, includes the interior of dip tube 28, the interior of housing 24, valve apertures 58, the interior of stem 26 and conduit 34 of displaceable member 32. Discharge orifice 36 is dimen-sioned and configured to have a circular cross-sectional flow area that does not exceed the cross-sectional flow area of the internal flow gate by more than a factor of 10. In order to adapt a conventional dispensing device for use with the present invention, one may position a flow path-narrowing insert 60 in the oversized outlet, as shown in Figure 1. Insert 60 is secured within the ori-fice and has an internal passage that provides a reduced discharge orifice in accordance with the present inven-tion.
To ameliorate the flammability problem of the propel-lant-rich top layer of fluid that can accumulate in the dip tube between uses, the aerosol product container 10 in accordance with the present invention comprises a dip tube 28 having a reduced internal volume. Specifically, dip tube 28 is a capillary style dip tube having an internal diameter in the range of about 0.03 to 0.06 inches (about 0.75 to 1.5 mm).
The combination of a capillary dip tube with a foaming soap product also reduces flammability risks when the valve is actuated with the can in an upside-down position.
Ordinarily, flame hazards are exaggerated in the upside-down position since the liquid composition falls away from the opening of the dip tube, allowing the propellant vapor to flow un-impeded through the valve assembly. However, the capillary dip tube of the present invention collects a smaller quantity of propellant therein, and discharge of propellant causes the foaming soap composition to bubble up inside the can and quickly reach the opening of dip tube 28. Accordingly, even in the upside-down position, aerosol product package 10 can emit educted propellant vapor only for a very short period of time, during which the exit velocity and spray pattern will be adequate to prevent flashback.
To further reduce flashback, the dispensing device may comprise a threshold bias spring rather than a conven-tional bias spring. The resistance offered by a conven-tional spring increases as the spring is compressed, thus resisting full actuation of the valve. In contrast, threshold bias spring 27a (Figure 4) which is a spring washer, is characterized in that the force needed to ini-tially open the valve is close to that required for fur-ther movement to its fully-open position. Therefore, if the user applies constant force sufficient to actuate the valve, the valve will tend to snap open, fully exposing valve apertures 58 to the interior of housing 24, and the user will be less likely to inadvertently depress the valve only part way. Full actuation of the valve ensures that the product will be dispensed at maximum exit veloci-ty, thus reducing the risk of flashback. Such springs are commercially available under the trade designation Belle-ville Spring Washers. Threshold bias spring 27a is shownin an enlarged scale in Figure 5A, in which the thickness t, the spring height H and the associated nominal dish or core dimension h of the spring are indicated.
The height H is the perpendicular distance from the base plane of the spring, i.e., from the plane on which the spring can rest on its outer peripheral edge, to the top plane of the spring, i.e., the plane of the inner peripheral edge of the spring, parallel to the base plane, in which a load can contact the spring without causing deflection. By subtracting the thickness t from height H, the cone dimension h is derived. The proportion of h to t can be used to characterize the deflection characteristics of the spring. For example, the graph of Figure 5B shows three deflection curves for springs in which h = t, h =
0.5 t and h = 0.25 t. In the graph, the applied load is given as a percentage of the minimum load that will cause full deflection ("full deflection load"), and is shown on the ordinate, whereas the resulting deflection is shown on the abscissa as a percentage of full deflection (in which the spring is flattened). The graph shows, for example, that for a spring in which h = t, the initial 50% of full deflection requires 70% of full deflection load; the re-maining 50% deflection is attained by adding only 30% of the full deflection load. If the full deflection of a single spring washer does not provide adequate valve actu-ation, the springs can be stacked as shown in Figure SC
without defeating the threshold bias characteristic of the valve.
A typical foaming soap composition for use with the present invention comprises 26.3% water, 13.74% disodium cocoamphodiacetate, 13.74% low viscosity disodium cocoam-phodiacetate, 27.48% TEA lauryl sulfate, 0.56% lauramide DEA, 0.1% methyl paraben, 1% polysorbate 20, 0.5% fra-grance, 0.2% hydroxyethylcellulose, and 17% isobutane as the propellant. The composition has a specific gravity of 0.92 grams per milliliter (including the isobutane propel-lant) and a viscosity of 3000 cps. In addition, the re-sulting product is advantageously amphoteric, and so willnot cause any burning sensation should the user inadvert-ently get soap in his or her eyes. A charge of the fore-going soap composition was disposed in an aerosol contain-er sealed with a dispensing device in which the valve had two circular valve inlet apertures, each having a diameter of 0.024 inches (0.61 mm) defining a combined cross-sec-tional flow area of 0.9 X 10- 3 square inches (5.8 X 10- 3 cm2) and a housing to which a capillary dip tube having an internal diameter of 0.04 inches (1 mm) giving a cross-sectional flow area of 1.26 X 10-3 in2 (8.1 x 10-3 cm2 ) was attached. A button-style actuator having an iris spout defining a discharge orifice having a circular con-figuration with a diameter of 0.05 inches (1.27 mm) was secured on the valve. The cross-sectional flow area of the discharge orifice was accordingly 1.96 X 10- 3 square inches (12.7 X 10-3 cm2 ). Therefore, the ratio of the cross-sectional flow area of the discharge orifice to that of the valve inlet apertures was only 2.18:1, i.e., the discharge orifice was only about 220% larger than the in-ternal flow gate. The aerosol dispenser described abovewas tested for flame hazard safety by spraying the product through a flame with the container in both an upright and an upside-down position. The flame front did not exceed -18 inches and did not flash back to the dispenser.
While the invention has been described in detail with respect to specific embodiments thereof, it is to be un-derstood that upon a reading of the foregoing description,variations to the specific embodiments disclosed may occur to those skilled in the art and it is intended to include such variations within the scope of the appended claims.
Claims (14)
1. In a dispensing device defining a flow path termi-nating in a discharge orifice and through which flow path a fluid composition may be dispensed from the interior of a pressurized container on which the device is mounted, the device comprising mounting means to seal the device onto the container, a valve movable between a closed posi-tion and a fully-open position to control the flow rate of the composition through the flow path, and actuator means to move the valve between its closed and fully-open posi-tions, the device defining an internal flow gate having a cross-sectional flow area that limits the mass flow rate of fluid composition through the device at least when the valve is in its fully open position, the improvement com-prising that the discharge orifice has a cross-sectional flow area that does not exceed about 1000% of the cross-sectional flow area of the internal flow gate.
2. The device of claim 1 wherein the internal flow gate has a cross-sectional flow area of at least about 0.13 X 10-3 square inches (about 0.845 X 10-3 cm2).
3. The device of claim 2 wherein the internal flow gate has a cross-sectional flow area of from about 0.3 X
10- 3 to 2.8 X 10- 3 square inches (about 1.9 X 10- 3 to 18 x 10- 3 cm2) .
10- 3 to 2.8 X 10- 3 square inches (about 1.9 X 10- 3 to 18 x 10- 3 cm2) .
4. The device of claim 3 wherein the discharge orif-ice has a cross-sectional flow area of from about 0.3 X
10- 3 to 2.8 X 10- 3 square inches (about 2.0 x 10- 3 to 18 X
10- 3 cm2) .
10- 3 to 2.8 X 10- 3 square inches (about 2.0 x 10- 3 to 18 X
10- 3 cm2) .
5. The device of claim 2 wherein the internal flow gate comprises two valve inlet orifices each having a cross-sectional flow area of about 0.45 X 10-3 square inches (about 2.9 X 10-3 cm2 ), and wherein the discharge aperture has a circular configuration having a cross-sec-tional flow area of about 2 X 10-3 square inches (about 13 X 10-3 cm2).
6. The device of claim 3 or claim 4 comprising a dip tube that extends into the interior of the container and is connected in flow communication with the valve to thereby define part of the flow path, the dip tube having a cross-sectional flow area of from about 0.7 X 10-3 square inches to 2.8 X 10-3 square inches (about 4.5 X
10-3 to 18.3 X 10-3 cm2).
10-3 to 18.3 X 10-3 cm2).
7. The device of claim 1 further comprising a thresh-old bias spring mounted therein to bias the valve into its closed position and to accelerate full opening of the valve upon commencement of opening actuation of the valve.
8. The device of claim 1 or claim 2 wherein the corss-sectional flow area of the discharge orifice is about 220% as large as that of the internal flow gate.
9. A dispenser package for dispensing a fluid compo-sition comprising:
a pressurized container containing a fluid compo-sition and a flammable propellant, the fluid composition having at 20°C a viscosity within the package of at least about 1000 cps;
a dispensing device mounted on the container and defining a flow path terminating in a discharge orifice and through which flow path the fluid composition may be dispensed from the interior of the container and defining an internal flow gate having a cross-sectional flow area of at least about 0.13 X 10-3 square inches (about 0.845 X
a pressurized container containing a fluid compo-sition and a flammable propellant, the fluid composition having at 20°C a viscosity within the package of at least about 1000 cps;
a dispensing device mounted on the container and defining a flow path terminating in a discharge orifice and through which flow path the fluid composition may be dispensed from the interior of the container and defining an internal flow gate having a cross-sectional flow area of at least about 0.13 X 10-3 square inches (about 0.845 X
10-3 cm2), the internal flow gate limiting the mass flow rate of the fluid composition through the device at least when the valve is in its fully open position, the dispens-ing device comprising mounting means to seat the device on the container, a valve movable between a closed position and a fully-open position to control the flow of the fluid composition through the flow path, and actuator means to move the valve between its closed and fully-open posi-tions, the improvement comprising that the discharge ori-fice has a cross-sectional flow area that does not exceed about 1000% of the cross-sectional flow area of the inter-nal flow gate.
10. The dispenser package of claim 9 wherein the fluid composition comprises a foaming soap composition and wherein the propellant is a normally gaseous propellent which is at least partly soluble in the foaming soap com-position.
10. The dispenser package of claim 9 wherein the fluid composition comprises a foaming soap composition and wherein the propellant is a normally gaseous propellent which is at least partly soluble in the foaming soap com-position.
11. The dispenser package of claim 10 wherein the foaming soap composition has, at 20°C, a specific gravity within the package of from about 0.9 to 1.0 g/cc.
12. The dispenser package of claim 10 wherein the foaming soap composition, inclusive of the propellant dis-solved therein, has at 20°C a specific gravity of from about 0.90 to 0.94 g/cc and a viscosity of from about 2000 to 4000 cps, the valve comprises an internal flow gate having a cross-sectional flow area of from about 0.45 X
10- 3 to 2.8 10- 3 square inches (about 2.9 X 10- 3 to 18.1 X 10- 3 cm2 ), the discharge orifice has a cross-sectional flow area of from about 1.2 X 10- 3 to 8 X 10- 3 square inches (about 7.7 X 10-3 to 18.1 X 10- 3 cm2) and the pro-pellant comprises a flammable liquified gas.
10- 3 to 2.8 10- 3 square inches (about 2.9 X 10- 3 to 18.1 X 10- 3 cm2 ), the discharge orifice has a cross-sectional flow area of from about 1.2 X 10- 3 to 8 X 10- 3 square inches (about 7.7 X 10-3 to 18.1 X 10- 3 cm2) and the pro-pellant comprises a flammable liquified gas.
13. The dispenser package of claim 12 wherein the cross-sectional flow area of the discharge orifice is about 220% as large as that of the internal flow gate.
14. The dispenser package of claim 12 wherein the in-ternal flow gate has a total cross-sectional flow area of about 0-9 X 10-3 square inches (about 5.8 X 10- 3 cm2 ) and the discharge orifice has a cross-sectional flow area of about 1.96 X 10-3 square inches (about 12.6 X 10-3 cm2 ) .
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US39468795A | 1995-02-27 | 1995-02-27 | |
| US08/394,687 | 1995-02-27 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2170445A1 true CA2170445A1 (en) | 1996-08-28 |
Family
ID=23560010
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2170445 Abandoned CA2170445A1 (en) | 1995-02-27 | 1996-02-27 | High velocity foam dispensing device and dispensing package including the same |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2170445A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11253111B2 (en) | 2019-08-22 | 2022-02-22 | Gpcp Ip Holdings Llc | Skin care product dispensers and associated self-foaming compositions |
-
1996
- 1996-02-27 CA CA 2170445 patent/CA2170445A1/en not_active Abandoned
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11253111B2 (en) | 2019-08-22 | 2022-02-22 | Gpcp Ip Holdings Llc | Skin care product dispensers and associated self-foaming compositions |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Dead |