An aerosol dispenser of the hand-held type adapted to discharge fluid under pressure when held in either an upright or an inverted position. The dispenser comprises a can or container, an actuator valve carried thereby and a special dip tube assembly including concentric inner and outer tubes defining an annular channel therebetween. The inner dip tube at one end is carried on a hollow depending boss which communicates with the interior of the valve housing. The outer dip tube is similarly carried at one end, but on a larger diameter, notched portion of the housing, the notches providing communication between the annular channel and the upper interior of the can adjacent the valve. The other end of the outer dip tube carries a gravity-operated check valve. The arrangement is such that when the container is in the upright position, the check valve is open whereby the inner dip tube can receive fluid directly from the lower part of the container to be discharged through the actuator valve. In the inverted position, the check valve closes to prevent the propellant gas in the container from escaping. Fluid is then drawn past the notches in the housing and into the annular channel. It thereafter enters the inner dip tube and is discharged through the actuator valve.
This invention relates generally to small aerosol dispensers of the hand-held type, and more particularly to dispensers adapted to operate in either an upright or an inverted position. In the past, a number of different arrangements have been proposed and constructed to accomplish this. U.S. Pat. No. 3,545,488 discloses a dispenser of the type having a first dip tube connected to the actuator valve, a check valve connected with the free end of the first tube, and an additional dip tube carried at one end by the check valve and having its free end disposed adjacent the closure dome of the container.
An alternate embodiment (FIG. 7) discloses a single dip tube which has coextensive passages which are isolated from one another, one of which has a circular cross sectional configuration and the other of which has crescent-shaped cross sectional configuration.
While these constructions operated in a generally satisfactory manner, several disadvantages were apparent with each. Specifically, in the constructions of the above identified patent, the free end of the second dip tube did not always occupy a position below the level of the fluid when the container was disposed in a horizontal position. The use of a weighted check valve to orient the free end of the second dip tube to a position below the level of fluid in a tilted container constituted a somewhat less than satisfactory solution to such a problem. Where a single dip tube having separate coextensive channels was employed, the manufacturing costs went up, since extruded tubing of this nature was inherently more expensive to produce than conventional tubing. In addition, where such specially molded tubing was connected to valve housing, the latter had to be provided with identically molded ports.
The above disadvantages and drawbacks of prior aerosol dispensers of the upright-inverted type are obviated by the present invention which has for its object the provision of a novel and improved dispenser of the kind indicated which is extremely simple in construction, effective in operation and economical to manufacture, assemble and produce. A related object is the provision of a dispenser as above characterized which is constituted of few separate pieces and which can employ simple molded parts and readily available inexpensive extruded plastic tubing requiring no special tooling or special fabrication equipment.
The above objects are accomplished by the provision of an aerosol dispenser comprising a pressurized container and actuator valve carried thereby, and a special dip tube assembly connected with the valve to enable discharge of the contents of the dispenser from either an upright or an inverted position. The dip tube assembly comprises inner and outer dip tubes, the latter carrying a check valve at one end. The tubes are generally concentric, and the end of the inner dip tube adjacent the check valve is free and unattached. The other end of the inner dip tube is carried on a depending nipple on the valve housing so as to communicate with the interior thereof. The tubes thus define an annular channel, and this communicates with the interior of the container at a location adjacent the actuator valve. The arrangement is such that when the container is upright, the check valve is open and fluid from the bottom of the dispenser can enter the inner dip tube through the check valve to thereby be discharged through the actuator valve. When the dispenser is inverted, the check valve closes, thus preventing escape of the propellant gas. Fluid from the top of the inverted container enters the annular channel, and from there is discharged through the inner dip tube. The provision of concentric dip tubes and a simple check-valve pressed into the bottom end of one constitutes an extremely simple and effective construction which has the important advantage of low tooling and assembly cost.
Other features and advantages will hereinafter appear.
In the drawings, illustrating a preferred embodiment of the invention:
FIG. 1 is a vertical sectional view of the improved aerosol dispenser of the present invention, shown in an upright position.
FIG. 2 is a view like that of FIG. 1, except showing the depress button and valve being actuated to effect discharge of the dispenser contents.
FIG. 3 is a vertical sectional view of the improved aerosol dispenser of the present invention, shown in an inverted position.
FIG. 4 is a bottom plan view of the ball check valve part of FIGS. 1-3.
FIG. 5 is a top plan view of the ball check valve part of FIGS. 1-3.
FIG. 6 is a section taken on line 6--6 of FIG. 1.
FIG. 7 is a section taken on line 7--7 of FIG. 1.
Referring to FIGS. 1-3 there is illustrated an aerosol dispenser of the hand-held type generally designated by the numeral 10, comprising a container 12 having a top closure member 14 with an inverted cup portion 16 carrying a valve housing 18. A valve stem 20 extends through an opening 22 in the cup portion 16 and has an annular valve shoulder 24 which engages a valve seat 26 all in the usual manner. A spring 28 disposed in the valve housing 18 biases the stem 20 against the seat 26. The housing, stem, spring and seat constitute an actuator valve, hereinafter also referred to as a dispensing valve. The stem is further provided with a hollow bore 30 and a transverse passage 32 which provides communication between the valve housing 18 and the discharge nozzle 34 of a depress button 36. The valve housing is retained in the cup portion 16 by a crimped bead 38, and the closure member 14 is held in place on the container by a crimp 40.
Referring to FIG. 1 and in accordance with the present invention there is provided a novel and improved dip tube and check valve assembly for enabling discharge of the contents of the dispenser from either an upright or an inverted position. The assembly comprises an outer dip tube 42 and an inner dip tube 44 which is substantially concentric with and coextensive with the first (FIG. 7). The two tubes thus define an annular channel 46 therebetween. The outer dip tube 42 is pressed onto a large diameter portion 48 of the valve housing, the latter constituting mounting means therefor. This portion 48 has a plurality of notches or recesses 50 (FIG. 6) which define passages providing communication between the annular channel 46 and an area of the interior of the container adjacent the cup portion 16. The inner dip tube 44 engages a smooth annular external surface of a depending nipple 19 on the valve housing to form a substantially tight seal therewith.
As shown in FIGS. 1-3, the free end of the outer dip tube 42 carries a check valve 52 which is press-fitted therein. The valve 52 includes an annular valve casing 54 having a hollow bore 56 and inlet and outlet ports 58, 60, respectively. The valve casing 54 is particularly illustrated in FIGS. 4 and 5. A ball 62 constituting a movable valve part is held captive in the casting. Adjacent one end of the casing is an annular valve seat 64 which is engaged by the ball when the container is in the inverted position of FIG. 3. Under these circumstances, the port 60 is closed off. When the container is upright, the ball assumes the position shown in FIGS. 1 and 2 wherein it engages a plurality of detent nibs 65, the latter serving to maintain the ball captive. A plurality of longitudinal slots 66 in the casing 54 provide communication between the bore 56 and an area of the container adjacent its bottom. An annular shoulder 68 on the valve casing seats against the end of the dip tube 42 and during assembly limits the insertion of the casing to a predetermined amount.
Although FIGS. 1-3 show the dip tubes 42, 44 as being perfectly concentric, it is to be noted that the end of the inner dip tube 44 adjacent the check valve casing 54 is free and unattached. In practice, part of the inner dip tube may be disposed off center with respect to the axis of the outer dip tube, and may occupy a position of engagement at one or two points with the inner surface of this outer tube. Such a construction is intended to fall within the scope of the present invention as defined by the appended claims.
The operation of the improved aerosol dispenser of the invention can now be readily understood by referring to FIGS. 1-3. With the container in an upright position as in FIGS. 1 and 2, the ball 62 engages the nibs 65, and the bore 56 of the casing provides communication between the port 60 and annular channel 46, and the area of the container adjacent the bottom wall thereof. The level of liquid in the annular channel 46 will be the same as the level outside the dip tube. The pressure in the upper part of the channel 46 is similarly equal to that in the upper part of the container due to the notches 50 in the valve housing which provide for pressure equalization in these two regions. Depression of the button 36 will cause liquid to flow into the check valve casing 54 via the port 58 and the slots 66, past the ball 62 and out through port 60, and into dip tube 44 to be discharged in the usual manner through the valve housing 18 and stem 20. Such discharging is illustrated particularly in FIG. 2.
When the container is inverted as in FIG. 3, the ball 62 assumes a position in engagement with the valve seat 64, thus closing off the port 60 and sealing this end of the annular channel 46 from the adjacent area of the container bottom. A level of fluid in the inner dip tube will be established in FIG. 3 depending among other things upon the amount of fluid in the container when it was inverted. However, this level will not necessarily equal the level of fluid in the inverted container. When the valve stem 20 is depressed, the fluid occupying the inner dip tube will gradually be discharged. Since the port 60 is closed, the pressure of the propellant in the can will cause fluid from the area adjacent the cup portion 16 to flow into the annular channel 46 via the notches 50. Prolonged actuation will gradually deplete the fluid in the inner dip tube, but before full depletion occurs, additional fluid will be forced upward through the annular channel and will spill over the lip of the inner dip tube to replenish the supply therein. Thus, little or no propellant gas is lost, either from the bottom portion of the inverted container or from the residual gas occupying the portion of the inner dip tube adjacent its free end.
From the above it can be seen that we have provided a novel and improved dispenser adapted to be actuated from either an upright or an inverted position. The above construction has the advantage of extreme simplicity and low cost, since the dip tubes can be economically fabricated from extruded plastic, and the check valve molded as a single piece. The various parts are then merely pressed together and assembled to the valve housing. The device thus represents a distinct advance and improvement in dispenser technology.
Variations and modifications are possible without departing from the spirit of the invention.