BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to liquid discharge devices of the type having no moving parts and which reverberate and pulsate the liquid within the device to produce a discharge of discrete droplets.
2. Description of the Prior Art
Liquid discharge devices which inherently cause a reverberating and pulsating effect to liquid discharged therefrom are known; see my prior U.S. Pat. Nos. 3,082,961, 3,341,133, and 3,547,351, each assigned to the assignee of the present invention, and see U.S. Pat. No. 3,301,493 to W. W. Frempter also assigned to the assignee of the present invention.
The structure which is common to all of these patents achieves liquid reverberation in a nozzle having a body defining an elongate inner chamber having ends spaced apart from each other by the length of the chamber. A liquid inlet opening is defined adjacent one end of the chamber and has an effective area less than the mean transverse cross-sectional area of the chamber. A liquid outlet opening is defined through the body laterally of the chamber and has an effective area greater than that of the liquid inlet opening.
It is the area of the inlet opening relative to the chamber and the area of the outlet opening relative to the inlet opening, in combination with the volume and configuration of the chamber, which provides the reverberating effect. The reverberation effect operates upon liquid in the chamber to produce a liquid discharge which is comprised of discrete droplets which are expelled through the outlet opening along paths which vary within wide limits with the reverberation effect.
SUMMARY OF THE INVENTION
The liquid discharge device of this invention has no moving parts and is of the type above described in that the liquid discharged therefrom reverberates and pulsates. In this invention, however, such devices are specially structured to produce a liquid discharge capable of assuming numerous patterns of varying shape and configuration in an entirely random manner. Switching between discharge patterns occurs entirely automatically at random intervals. Devices according to this invention are particularly useful as ornamental fountain nozzles.
In viewing the discharge produced by a device of the present invention, it appears as if some person is somehow regulating the liquid flow rate and/or outlet opening to achieve such random patterns. Such, however, is not the case. One moment the pattern can be in the form of a churning and bubbling water dome only 5 feet high and the next moment the discharge may spurt up 30 feet in a straight stream. After a while, the discharge descends again and may assume yet another configuration. Also, the time span between high and low discharges may differ during each cycle.
The variance of discharge patterns, the random changes, the unscheduled and apparently unpredictable cyclic periods occur completely automatically once an optimum liquid flow rate is established. No external control, either mechanical or human, is used to achieve the desirable pattern randomness.
Generally speaking, the uniquely random and unpredictable discharge pattern is produced by defining an aspiration opening laterally through an outlet tube between opposite ends of the tube. The outlet tube is mounted to the device's body with one end thereof in liquid flow communication with the liquid outlet opening from the body. The mean transverse cross-sectional area of the outlet tube is at least as great as the effective area of the liquid outlet opening from the body and is substantially greater than the effective area of the aspiration opening.
Although the precise theory behind discharge pattern randomness is not entirely known, it is known to be caused by the above structural properties in combination with an optimum liquid flow rate to be discerned empirically. Inclusion of the aspiration opening in the outlet tube is essential for pattern randomness. Air is sucked into this opening and is led into the liquid stream through the outlet tube. This air intake is apparently the main cause of pattern randomness.
BRIEF DESCRIPTION OF THE DRAWING
The above-mentioned and other aspects and advantages of the present invention are more fully described with reference to the accompanying drawing, wherein:
FIG. 1 is a cross-sectional view of a liquid discharge device of this invention:
FIG. 2 is a cross-section view taken along lines 2--2 of FIG. 1;
FIG. 3 is a view taken along lines 3--3 of FIG. 1;
FIG. 4 is a view taken along lines 4--4 of FIG. 1;
FIG. 5 is a cross-sectional view taken along lines 5--5 of FIG. 1;
FIG. 6 is a view similar to that of FIG. 3 concerning another liquid discharge device according to this invention; and
FIG. 7 shows a liquid discharge fountain having a plurality of identical devices of this invention, each device shown producing a differing discharge pattern.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A liquid discharge device 10 according to this invention is shown in FIG. 1. Device 10 has a tubular body 12 of cylindrical configuration, such as, but not confined to, a right-circular cylinder. Body 12 is hollow, thereby defining an inner chamber 14, and has opposite ends 16 and 18. An inlet plug 20 is disposed within the body adjacent body end 16 to close the body tube but for an inlet opening 22 which, as shown in FIG. 2, is formed through plug 20. A segment 23 of body 12 adjacent end 16 is threaded for screwing the device onto the threaded conduit of a source of pressurized liquid (not shown).
The precise position of inlet plug within chamber 14 is not critical for reverberation to occur, but it must be between an outlet opening 24 of the body and end 16. Furthermore, the precise shape of inlet opening 22 is not critical to the reverberation phenomena produced in the device; what is important is that inlet opening 22 have an effective cross-sectional area which is less than that of outlet opening 24 of the body and is substantially less than the mean transverse area of chamber 14. For good results, it is desired that inlet opening 22 have substantially the configuration shown in FIG. 2 and be aligned in the body with outlet opening 24 from chamber 14.
Outlet opening 24, shown more clearly in FIG. 3, is defined laterally through body 12 at a point therealong substantially closer to body end 18 than to end 16. As with the inlet opening, the precise shape of outlet opening 24 is not critical for reverberation to occur. It is important, however, that the effective cross-sectional area of opening 24 be greater than that of inlet opening 22. Furthermore, the precise location of outlet opening 24 along body 12 is not critical as long as it is laterally through body 12 and between the ends of the chamber. Variations in the position of outlet opening 22 along the body will produce variations in the degree of reverberation, however.
A solid plug 26 is disposed in body tube 12 at its end 18 and closes such end. Thus, liquid entering chamber 14 and passing through inlet opening 22 is directed out of the chamber through outlet opening 24. It is believed that the fact that outlet opening 24 has a greater cross-sectional area than that of inlet opening 22, coupled with the fact that the outlet opening is located laterally through the side of the chamber and not precisely at one end thereof, results in the desired reverberation and pulsation phenomena.
Device 10 includes an outlet tube 28 of cylindrical configuration. Tube 28 is hollow thereby defining therein a chamber 30 having opposite open ends 32 and 34 spaced apart by the length of chamber 30. Tube 28 is preferably right-circular cylindrical in shape and is mounted to body 12 with open end 32 of chamber 30 in liquid flow communication with outlet opening 24. Mounting may be accomplished by numerous known means, such as a saddle mount 36 as shown in FIG. 1. Tube 28 is preferably mounted with its axis perpendicular to the axis of body 12. Also, it is preferred that chamber 30 have a length which is greater than its diameter, in the case of a round chamber, or greater than its mean transverse dimension where the chamber is other than circular in cross-section.
Open end 32 of chamber 30 defines a liquid inlet opening into tube 28; whereas open end 34 defines a liquid outlet opening for the device. As is described in greater detail below, it is an important feature of this invention that the liquid discharged from device outlet opening 34 be capable of assuming numerous patterns of varying shape and configuration in an entirely random manner with switching between patterns occurring entirely automatically at random intervals. To this end, it has been found important to structure tube 28 such that its mean transverse cross-sectional area is at least as great as, and preferably greater than, the effective area of body outlet opening 24; FIG. 1 illustrates the preferred situation for smaller devices according to this invention, while FIG. 6 illustrates the preferred situation for larger devices according to this invention.
It is essential, in order for the random pattern phenomenon to occur, that an aspiration opening 38 be defined laterally through outlet tube 28 between opposite open ends 32 and 34 thereof. It is further essential that the effective area of aspiration opening 38 be substantially less than the mean transverse cross-sectional area of outlet tube 28. The precise location of aspiration opening along tube 28 between ends 32 and 34 is not critical. Variance of the position will affect the periodicity of pattern change, however. Such variance also has an effect on the nature and extent of each discharge pattern.
Although the reason for the behavior of the liquid discharged from device 10 is not entirely known, it is believed to involve the dimensional relationship as above described in combination with the suction effects of aspiration opening 38. More specifically, air is sucked into the liquid flowing through tube 28 and it mixes with and aerates it. This interaction of air and liquid causes the discharge to fluctuate between relatively low discharges of a bubbling and churning nature to relatively high straight stream discharges. The periodicity between "highs" and "lows" varies randomly. Furthermore, the patterns for high and low discharges usually are different during each "cycle."
This random and entirely automatic fluctuation is most desirable since it gives the effect of the device being preprogrammed. The randomness and periodicity can be controlled in part by regulating the liquid flow rate through the device. It was found that a range of flow rates exists within which the pattern randomness phenomenon may occur for each device of this invention. A liquid flow rate less than this range may produce only a "low" type of pattern, whereas a liquid flow rate higher than such range may produce only a "high" type pattern. There is an optimum liquid flow rate for each nozzle of any given configuration and size which can be determined by trial and error.
In a preferred embodiment, water at a rate of about 250 gpm was supplied to device 10 wherein the body 12 was defined by nominal 3 inch Schedule 80 polyvinyl chloride pipe having a length of about 20 inches, inlet plug 20 was about 8 inches from body end 16 and had a length of about 3 inches, inlet opening 22 had an area of about 1.75 square inches, and outlet opening 24 was centered about 5 inches from body end 18 and had a diameter of about 2 3/8 inches. The outlet tube 28 was about 6-1/2 inches. The outlet tube was defined by a piece of 2 1/2 inch Schedule 40 polyvinyl chloride pipe having an inner diameter of about 2 3/8 inches. The aspiration opening had a diameter of 1 inch and was about 6 inches from device outlet opening 34. It was found that random pattern formations were achievable by this advice with water flow rates within the range of 200 to 300 gpm, 250 gpm being the optimum, however.
FIG. 6 pertains to a device 60 generally in accord with the foregoing description but which is larger than the exemplary device described immediately above. In device 60, opening 24' is round and outlet tube 28' has an inner diameter which is essentially equal to but no smaller than the diameter of hole 24'.
In order that devices according to this invention may be operated with maximum submergence in a fountain pool, thus producing an aesthetically appealing display, it is preferred that discharge device 10 include an air supply tube 60 which extends along the exterior of outlet tube 28 from an open upper end 61 which is disposed coplanar with the upper end of the outlet tube. The air supply tube has a closed lower end 62 disposed below the aspiration opening. The interior of the air supply tube is communicated to the aspiration opening 38 by an outlet opening 63 which is registered with the aspiration opening. Opening 63 is sized to prevent restriction of the aspiration opening. Thus, device 10 may be disposed in a fountain pool with the aspiration opening to the outlet tube located physically below the water level in the pool.
FIG. 7 shows four identical devices 40, 42, 44 and 46 of this invention, each similar to device 10. Four differently configured discharge patterns 48, 50, 52 and 54 are shown. These four patterns illustrate different discharge patterns which may be produced by any one of devices 40, 42, 44 and 46 operating under constant applied pressure and flowrate conditions. For instance, patterns 48, 50 and 52 are exemplary of "low" patterns which are bubbly, spouting and churning, whereas pattern 54 is exemplary of a "high" pattern in the form of a straight stream discharge. Each of the devices switches between a low and high pattern randomly, without warning, and during different periods of time. This randomness in the discharge characteristic of the devices is a principal factor contributing to the utility and appeal of the devices.
Although device 10 has been described with regard primarily to its aesthetic values, it has been discovered that it functions well as a foam nozzle. More specifically, a foamant may be sucked into tube 28 through aspiration opening from a foamant supply (not shown) via a tube (not shown) connected to the aspiration opening, thereby producing a foaming liquid discharge.
Although the present invention has been described with regard to a specifically described embodiment, it will be understood that various modifications and alterations may be made to the described structure without departing from the spirit of the invention. For this reason, the foregoing description should not be regarded as exhausting or limiting the forms which this invention may take.