Title:
PLURAL CHAMBERED, GRAVITY ORIENTED DISPENSER
United States Patent 3851800
Abstract:
A plural chambered, liquid dispenser which is oriented with respect to gravity in the pouring position to provide an accurately metered, repeatable discharge of the liquids stored within the dispenser. In the preferred embodiment two containers, each defining a chamber adapted to contain a liquid and each having a liquid discharge orifice and an air venting tube system, are secured with respect to each other so that gravity equally affects any liquids in the two chambers when the dispenser is in a pouring position. Simultaneous initiation of the discharge of the liquids is achieved by controlling the venting of air into the chambers through the positioning of the air venting tubes. Variations in the pouring threshold are obtained by adjusting the relative positions of the liquid discharge orifice and the air venting tube outlet in each container. A pour handle is provided for the consumer to orient the dispenser with respect to gravity during use.
US Patent References:
Variable-strength beverage dispenser
Heier - April 1952 - 2592279
Liquid dispenser
Brink - March 1957 - 2784875
COMPARTMENTIZED SUPPLY CONTAINER
Bagwell et al. - September 1973 - 3756470
Variable-strength beverage dispenser
Heier - April 1952 - 2592279
Liquid dispenser
Brink - March 1957 - 2784875
COMPARTMENTIZED SUPPLY CONTAINER
Bagwell et al. - September 1973 - 3756470
Application Number:
05/389994
Publication Date:
12/03/1974
Filing Date:
08/20/1973
View Patent Images:
Export Citation:
Assignee:
Cambridge Research and Development Group (Westport, CT)
Primary Class:
Other Classes:
222/129, 222/481.500
International Classes:
B65D81/32; G01F11/26; G01F11/10; B67D5/60
Field of Search:
222/42,129,145,478,481,481.5,482,484,485,486,488
Primary Examiner:
Reeves, Robert B.
Assistant Examiner:
Rolla, Joseph J.
Attorney, Agent or Firm:
Birch, Richard J.
Claims:
What I claim and desire to secure by Letters Patent of the United States is
1. A plural chambered, gravity oriented liquid dispenser comprising:
2. The dispenser of claim 1 further characterized by means for producing a constant proportionality between the discharge rates of any liquids in said first and second chambers when the dispenser is in the pouring position.
3. The dispenser of claim 1 further characterized by said first and second container means having a generally cylindrical configuration and being secured with respect to each other so that the longitudinal axes of the container means are substantially parallel.
4. The dispenser of claim 1 further characterized by said container means being sufficiently rigid to resist vacuum deformation.
5. The dispenser of claim 1 wherein said second container means is positioned within said first container means chamber.
6. The dispenser of claim 4 wherein said first and second container means have a generally cylindrical shape and are secured with respect to each other so that the longitudinal axes of said container means are substantially parallel.
7. The dispenser of claim 1 wherein said first and second chambers each have a longitudinal axis and wherein each of said air venting means outlets is located at a lower level than the corresponding liquid discharge orifice means when the corresponding chamber longitudinal axis is perpendicular to a vertical plane.
8. The dispenser of claim 1 wherein said first and second chambers each have a longitudinal axis and wherein each of said air venting means outlets is located at the same level as the corresponding liquid discharge orifice means when the corresponding chamber longitudinal axis is perpendicular to a vertical plane.
9. The dispenser of claim 1 wherein said first and second chambers each have a longitudinal axis and wherein each of said air venting means comprises a bottom vent tube secured with respect to the corresponding container and having an air inlet end in free fluid communication with the atmosphere and an air outlet end positioned within and in fluid communication with the corresponding chamber, said vent tubes each having a length greater than the length of the corresponding chamber measured along the longitudinal axis thereof.
10. The dispenser of claim 9 wherein a portion of each of said vent tubes has an arcuate configuration.
11. The dispenser of claim 10 wherein the arcuate portion of each of said vent tubes terminates at the air outlet of the vent tube.
12. The dispenser of claim 1 wherein said first and second chambers each have a longitudinal axis and wherein said first and second chambers are filled with corresponding first and second liquids to the same level when the dispenser is positioned with said chamber axes in a vertical plane.
13. A plural chambered, gravity oriented liquid dispenser comprising:
14. The dispenser of claim 13 further characterized by means for producing a constant proportionality between the discharge rates of any liquids in said first and second chambers when the dispenser is in the pouring position.
15. The dispenser of claim 13 further characterized by said first and second container means having a generally cylindrical configuration and being secured with respect to each other so that the longitudinal axes of the container means are substantially parallel.
16. The dispenser of claim 13 further characterized by said container means being sufficiently rigid to resist vacuum deformation.
17. The dispenser of claim 13 wherein said second container means is positioned within said first container means chamber.
18. The dispenser of claim 16 wherein said first and second container means have a generally cylindrical shape and are secured with respect to each other so that the longitudinal axes of said container means are substantially parallel.
19. The dispenser of claim 13 wherein said first and second chambers each have a longitudinal axis and wherein each of said air venting means outlets is located at a lower level than the corresponding liquid discharge orifice means when the corresponding chamber longitudinal axis is perpendicular to a vertical plane.
20. The dispenser of claim 13 wherein said first and second chambers each have a longitudinal axis and wherein each of said air venting means outlets is located at the same level as the corresponding liquid discharge orifice means when the corresponding chamber longitudinal axis is perpendicular to a vertical plane.
21. The dispenser of claim 13 wherein said first and second chambers each have a longitudinal axis and wherein each of said air venting means comprises a bottom vent tube secured with respect to the corresponding container and having an air inlet end in free fluid communication with the atmosphere and an air outlet end positioned within and in fluid communication with the corresponding chamber, said vent tubes each having a length greater than the length of the corresponding chamber measured along the longitudinal axis thereof.
22. The dispenser of claim 21 wherein a portion of each of said vent tubes has an arcuate configuration.
23. The dispenser of claim 22 wherein the arcuate portion of each of said vent tubes terminates at the air outlet of the vent tube.
24. The dispenser of claim 13 wherein said first and second chambers each have a longitudinal axis and wherein said first and second chambers are filled with corresponding first and second liquids to the same level when the dispenser is positioned with said chamber axes in a vertical plane.
25. A plural chambered, gravity oriented, liquid dispenser comprising:
26. A plural chambered, gravity oriented, liquid dispenser comprising:
27. A plural chambered, gravity oriented, liquid dispenser comprising:
1. A plural chambered, gravity oriented liquid dispenser comprising:
2. The dispenser of claim 1 further characterized by means for producing a constant proportionality between the discharge rates of any liquids in said first and second chambers when the dispenser is in the pouring position.
3. The dispenser of claim 1 further characterized by said first and second container means having a generally cylindrical configuration and being secured with respect to each other so that the longitudinal axes of the container means are substantially parallel.
4. The dispenser of claim 1 further characterized by said container means being sufficiently rigid to resist vacuum deformation.
5. The dispenser of claim 1 wherein said second container means is positioned within said first container means chamber.
6. The dispenser of claim 4 wherein said first and second container means have a generally cylindrical shape and are secured with respect to each other so that the longitudinal axes of said container means are substantially parallel.
7. The dispenser of claim 1 wherein said first and second chambers each have a longitudinal axis and wherein each of said air venting means outlets is located at a lower level than the corresponding liquid discharge orifice means when the corresponding chamber longitudinal axis is perpendicular to a vertical plane.
8. The dispenser of claim 1 wherein said first and second chambers each have a longitudinal axis and wherein each of said air venting means outlets is located at the same level as the corresponding liquid discharge orifice means when the corresponding chamber longitudinal axis is perpendicular to a vertical plane.
9. The dispenser of claim 1 wherein said first and second chambers each have a longitudinal axis and wherein each of said air venting means comprises a bottom vent tube secured with respect to the corresponding container and having an air inlet end in free fluid communication with the atmosphere and an air outlet end positioned within and in fluid communication with the corresponding chamber, said vent tubes each having a length greater than the length of the corresponding chamber measured along the longitudinal axis thereof.
10. The dispenser of claim 9 wherein a portion of each of said vent tubes has an arcuate configuration.
11. The dispenser of claim 10 wherein the arcuate portion of each of said vent tubes terminates at the air outlet of the vent tube.
12. The dispenser of claim 1 wherein said first and second chambers each have a longitudinal axis and wherein said first and second chambers are filled with corresponding first and second liquids to the same level when the dispenser is positioned with said chamber axes in a vertical plane.
13. A plural chambered, gravity oriented liquid dispenser comprising:
14. The dispenser of claim 13 further characterized by means for producing a constant proportionality between the discharge rates of any liquids in said first and second chambers when the dispenser is in the pouring position.
15. The dispenser of claim 13 further characterized by said first and second container means having a generally cylindrical configuration and being secured with respect to each other so that the longitudinal axes of the container means are substantially parallel.
16. The dispenser of claim 13 further characterized by said container means being sufficiently rigid to resist vacuum deformation.
17. The dispenser of claim 13 wherein said second container means is positioned within said first container means chamber.
18. The dispenser of claim 16 wherein said first and second container means have a generally cylindrical shape and are secured with respect to each other so that the longitudinal axes of said container means are substantially parallel.
19. The dispenser of claim 13 wherein said first and second chambers each have a longitudinal axis and wherein each of said air venting means outlets is located at a lower level than the corresponding liquid discharge orifice means when the corresponding chamber longitudinal axis is perpendicular to a vertical plane.
20. The dispenser of claim 13 wherein said first and second chambers each have a longitudinal axis and wherein each of said air venting means outlets is located at the same level as the corresponding liquid discharge orifice means when the corresponding chamber longitudinal axis is perpendicular to a vertical plane.
21. The dispenser of claim 13 wherein said first and second chambers each have a longitudinal axis and wherein each of said air venting means comprises a bottom vent tube secured with respect to the corresponding container and having an air inlet end in free fluid communication with the atmosphere and an air outlet end positioned within and in fluid communication with the corresponding chamber, said vent tubes each having a length greater than the length of the corresponding chamber measured along the longitudinal axis thereof.
22. The dispenser of claim 21 wherein a portion of each of said vent tubes has an arcuate configuration.
23. The dispenser of claim 22 wherein the arcuate portion of each of said vent tubes terminates at the air outlet of the vent tube.
24. The dispenser of claim 13 wherein said first and second chambers each have a longitudinal axis and wherein said first and second chambers are filled with corresponding first and second liquids to the same level when the dispenser is positioned with said chamber axes in a vertical plane.
25. A plural chambered, gravity oriented, liquid dispenser comprising:
26. A plural chambered, gravity oriented, liquid dispenser comprising:
27. A plural chambered, gravity oriented, liquid dispenser comprising:
Description:
BACKGROUND OF THE INVENTION
The present invention relates to liquid dispensers and more particularly, to a plural chambered, gravity oriented dispenser which provides an accurately metered, repeatable discharge of two or more liquids.
The art of plural chambered, liquid dispensers is relatively old and well developed. Representative examples of such pour type liquid dispensers are shown in British Pat. No. 505,875 and in the following U.S. Letters Pat. Nos. 2,438,906; 2,592,279; 2,661,870; 2,661,871; 2,665,816; 2,784,875; and 3,729,553. Among the dispensers described in the above listed patents, the Claudel dispenser, British Pat. No. 505,875, the Brink liquid dispenser No. 2,784,875 and the Heier variable-strength beverage dispenser No. 2,592,279 each depict a dispenser which provides for the variable ratio dispensing of two liquids. In the Heier variable-strength beverage dispenser air is vented into the liquid storage chambers through the liquid discharge orifice itself. In contrast, the dispensers shown in Brink and Claudel employ separate air returns to the liquid storage chambers. Although these patents disclose plural chambered, liquid dispensers which provide variable ratio dispensing of the liquids stored therein, the particular structures of these dispensers do not provide the requisite degree of metering accuracy and consistency which is desired for certain liquid dispensing applications.
It is accordingly a general object of the present invention to provide a plural chambered, liquid dispenser which dispenses two liquids at a predetermined ratio with extreme accuracy and consistency.
It is a specific object of the present invention to provide a plural chambered, liquid dispenser which utilizes a gravity response system to provide metering accuracy and consistency.
It is another object of the present invention to provide a plural chambered, liquid dispenser which has no moving parts and does not require special molding techniques.
It is still another object of the present invention to provide a plural chambered, liquid dispenser which consistently and accurately dispenses two or more liquids by utilizing a consistent orientation to gravity.
It is a feature of the present invention that the dispenser liquid containers can be fabricated inexpensively from a variety of materials including glass.
It is another feature of the invention that the dispenser is capable of dispensing over a wide range of predetermined dispensing ratios.
It is still another feature of the invention that the configuration of the dispenser automatically dictates to the user the correct pouring position for achieving simultaneous discharge of the liquids.
In the accomplishment of these objects, the preferred embodiment of the invention employs two rigid liquid containers, one positioned within the other and commonly attached to a large overcap. Each of the containers has a liquid metering orifice and an air return through the overcap. A common closure cap seals the air returns and the liquid orifices to close the containers and prevent cross contamination between the stored liquids. A pour handle is provided on the outer container to orient the dispenser to gravity during use. This guarantees that the force of gravity will always have the same effect on the dispensing performance of the dispenser.
To use the dispenser of the present invention the consumer removes the closure cap, grasps the handle and pours. As the dispenser is tipped, the two liquids approach their respective metering orifices. No liquid flows out of the dispenser until air is vented into each liquid containing chamber. Both of the liquid container air returns are designed in such a way as to be equally sensitive to the position of the dispenser. Once the consumer has tipped the dispenser beyond a predetermined threshold angle, air is simultaneously vented into each chamber and both liquids begin to pour in steady streams. As long as the consumer continues to pour, the two streams flow as a function of gravity and the size of the metering orifices. As soon as the dispenser is returned past the pouring threshold angle, the air returns stop venting air into the liquid containing chambers and dispensing terminates.
The objects and features of the present invention will best be understood from a detailed description of a preferred embodiment thereof selected for purposes of illustration and shown in the accompanying drawings, in which:
FIG. 1 is a perspective view of a plural chambered, gravity oriented dispenser constructed in accordance with the present invention;
FIG. 2 is a view in partial cross-section showing the dispenser of FIG. 1 with a modified pouring handle and a slightly different container configuration;
FIG. 3 is a diagrammatic view of a simplified dispenser constructed in accordance with the present invention which illustrates the relationships of the containers, liquid discharge orifices and air venting systems; and,
FIG. 4 is another view similar to that of FIG. 3 showing the dispenser thereof in the pouring position.
Turning now to the drawings, there is shown a dispenser constructed in accordance with the present invention and indicated generally by the reference numeral 10. The dispenser 10 comprises an outer container 12 which defines an outer chamber 14 which is adapted to contain a first liquid and an inner container 16 which defines a corresponding inner chamber 18 which is adapted to contain a second liquid. The two containers 14 and 16 are secured with respect to each other by means of a threaded overcap 20. The dispenser is provided with a handle 22 which may be separate from the overcap 20 as shown in FIG. 1 or formed as an integral part of the overcap as shown in FIG. 2.
The outer container 12 has a liquid discharge orifice 24 and an air venting system indicated generally by the reference numeral 26. The air venting system comprises an air vent tube 28 which is secured with respect to the outer container 12 and has an air inlet 30 which is in free communication with the atmosphere. The other end of the air vent tube 28 terminates in an air outlet 32 which is positioned within and in fluid communication with the outer container chamber 14. A similar structural arrangement is provided for the inner container 16 with a liquid discharge orifice 34 and an air venting system 36 comprising an air vent tube 38 with an inlet 40 and an air outlet 42 positioned within and in fluid communication with the inner container chamber 18. Preferably, the inner and outer chamber liquid discharge orifices 24 and 34 discharge into a common outlet 44 formed in an exteriorly threaded pour spout 46. The common outlet 44 is closed by means of a threaded closure cap 48 as shown in FIG. 1.
The operation of the plural chambered, gravity oriented liquid dispenser of the present invention can best be understood by reviewing first the liquid flow characteristics of a single dispenser and then analyzing the operation of the dual dispenser shown in the drawings with particular emphasis on the diagrammatic views of FIGS. 3 and 4.
Assuming that a liquid flow container has an unlimited free surface (upper surface is continuously exposed to atmospheric pressure) there are three dimensions that affect liquid flow from an orifice: the head (height of liquid directly above the orifice), the size of the orifice, and the cross sectional area of the free surface.
The first of these, the head, affects the velocity of flow. This can be easily observed when a bottle is poured at an angle of 45°. When full, the stream of liquid from the bottle will flow outward and downward and pour into a glass perhaps a foot from the bottle. As the bottle empties, the curve will become smaller until finally trickling straight down. This curve is an indication of the velocity of the flow and is dependent on the head. The formula for the velocity is V=√2gh, where g is the mathematical constant for acceleration due to gravity (equal to 980.62 cm/second 2 ) and h is the head (height of the liquid in centimeters).
The second dimension, orifice size, works in conjunction with velocity to describe the amount of liquid that is flowing. This is called discharge. Returning to the example of the bottle poured at a 45° angle, this second dimension, the area of the orifice, can be understood by placing a container at the end of the stream and collecting the discharge per second. It might be, arbitrarily, 0.3 in 3/sec. If the size of the orifice is now increased and the discharge collected again, one would find an increase in discharge in proportion to the amount one increased the size of the orifice. The formula for discharge is Q=A o √2gh where Q is the discharge and A o is the area of the orifice.
In theory, the area of the stream of a liquid is equal to the area of the orifice. In practice, it is less. Friction, viscosity, surface tension, etc., reduce the size of the stream and rate of velocity by a coefficient of discharge, C d which enters into the formula for discharge. Q a =C d A o √2gh is an equation more closely approximating practical experience. There are no rules for determining C d , it must be derived experimentally. Typically, for water dispensed from bottles and orifices of consumer dimensions, it is 0.88.
The third dimension, the cross-sectional area of the free surface defines (in conjunction with head) the volume of the liquid and affects the duration of discharge. For instance, if a wide round bottle and a narrow round bottle were both filled to the same height (equal head) the wide bottle would contain the greater volume of liquid as a function of its greater cross-sectional area (width). If both had the same orifice size, the wider bottle (with the greater amount of liquid) would discharge for a longer amount of time. Another example envisions two bottles, a wide round bottle and a narrow round bottle both filled with the same amount of liquid. The fill level of the narrow round bottle would obviously be higher. If both bottles had the same size orifice, the narrow bottle would discharge its liquid faster as a result of its greater head pressure. Hence, the same amount of liquid always flows out of tall, narrow bottles faster than shorter, wider bottles with the same size orifice. Tapered neck bottles take advantage of this fact by effectively speeding up flow in the lower head range by decreasing cross-sectional area (or actually increasing head per unit volume).
The formula for the time required to pour from height Y 1 , to height Y 2 is
t = - 1/C d A o √2g ∫ Y 2 /Y 1 A r Y - 1 /2 dy
When the bottle has a constant cross-section, the equation simplifies to
t = 2 A r /C d A o √2g (√Y 1 - √Y 2 )
Of the many variables that affect liquid flow, two variables, angle of pour and orifice configuration, are especially contributory to bottle performance. Pouring angle affects flow because head is a measure of the vertical component of a liquid column and it is shortened as the bottle axis approaches the horizon. Hence, velocity and, consequently, discharge rate increases as the bottle is tilted more towards vertical.
Another important variable is the shape of the orifice. There are critically engineered orifices that produce virtually no C d . For the present invention, an efficient design would include rounded metering entrances and short capillary tubes as opposed to normal orifices.
Up to this point, the discussion has focused on containers with unlimited free surfaces. Consumer pour bottles do not afford unlimited free surfaces and require some method of air replacement to allow pouring. Simple pour bottles return air through the liquid orifice causing the usual glub, glub sound and irregular pouring. To affect more consistent flow and/or to regulate the amount of flow, separate air returns are incorporated such as are often found on gasoline cans. Flow is still somewhat irregular with the separate air returns since the returning air must bubble through the liquid. A long tube attached to the air return can further improve flow by providing a direct, liquid-free air route to the air space in the container. These tubes, however, become partially filled with liquid when the bottle is sitting upright and care must be taken to prevent these tubes from becoming clogged with liquid when inverted. This situation is referred to as a stall because the clogged air return will not allow dispensing until it is cleared of liquid.
Control of orientation can prevent stalls by dictating that the air will always return through the air return and liquid will always flow unrestricted out the liquid orifice. One of the optimum relationships orientates the air return orifice above the liquid orifice when the dispenser tilts toward horizontal as shown in FIGS. 3 and 4. This orientation brings greater head pressure to bear on the liquid at the lower liquid orifice than on the liquid at the higher air orifice thus creating greater potential for flow for the lower orifice.
Dimensional relationships of the liquid and air orifices additionally dictate flow direction. For instance, the liquid orifice should be larger than the air orifice to provide greater potential for liquid flow out of the liquid orifice. This relationship is improved by the head pressure differential provided by proper orientation as explained above.
Since air return dispensing threshold is a requirement for liquid dispensing, flow of liquid can be initiated and ceased by controlling the air return system. The air return sequence to a bottle with an air return tube can be explained with reference to the siphon. All exposed free surfaces of a body of liquid attempt to remain at equal heights and any situation which causes an imbalance will cause flow to equalize the fluid levels. Sitting upright, such a container has two exposed liquid free surfaces, the liquid in the container exposed to atmosphere by the open liquid orifice, and the liquid in the air return tube exposed to atmosphere by the air orifice. The liquid in the air return tube is at the same height as the liquid in the bottle (actually the liquid in the air return tube often is a little higher due to an unrelated phenomenon -- capillary action). When the bottle is tilted to pour, the liquid level changes to approach the liquid orifice. The liquid in the air return tube also changes to adjust for the new liquid level.
As the bottle is tilted more, the liquid covers the liquid orifice isolating the formerly free surface from the atmosphere and entrapping it within the interior of the container. The liquid covering the orifice becomes the exposed free surface. As the bottle is tilted further, the liquid in the air return tube continues to adjust until it reaches the same level as the liquid at the orifice. At some point, the liquid in the air return tube, in seeking to continue reaching equilibrium, completely evacuates the air return tube. Air now has uninhibited communication with the interior of the bottle venting atmospheric pressure and allowing the free flow of liquid out of the container.
The previous dual dispensing discussion has described force of gravity, its effect on discharge, the need of air replacement and various ways to control the air return to regulate and initiate flow. The simplest form of dual dispensing would be to take two bottles of the same height and cross-sectional configuration and fit them each with a cap with the same orifice size and same length and size air return tubes. If both were filled to the same level, orientated with the air returns over the liquid orifices and simultaneously inverted, one would have a simple 1:1 co-dispenser.
If a 3:1 simple co-dispenser is desired, one bottle is replaced with another bottle that has three times the cross-sectional area and an orifice adjusted for three times the volume flow. With height remaining the same, the duration of discharge would be the same for both, but the wider bottle, with the larger orifice, would discharge three times the amount of liquid. In order to control the simultaneous flow of the liquids, the two bottles are similarly orientated and attached each to each other and to a handle. If both air returns are of the same length and angle in relationship to their liquid orifice, tipping the filled bottles to threshold will cause simultaneous dispensing.
Looking now at FIGS. 3 and 4, the dispenser 10 is shown diagrammatically in FIG. 3 in a non-pouring position with the axes of the inner and outer chambers parallel to a horizon line 50 and in FIG. 4 with the chamber axes positioned below the horizon line 50. The horizon 50 is perpendicular to a vertical plane which contains the gravity vector. For purposes of this application, the term "vertical plane" shall mean a plane which is vertical to the earth's surface and which contains the gravity vector. The horizon line 50 represents the earth's surface and is, of course, perpendicular to the "vertical plane."
In addition to the container axes and the horizon line 50, the diagrammatic views of FIGS. 3 and 4 also include two air venting reference lines 52 and 54. Air venting reference line 52 is defined by the two points of the center of the outer container liquid discharge orifice 24 and the center of outer container air vent tube outlet 32. The other air venting reference line 54 is similarly defined by the center of the inner container liquid discharge orifice 34 and the center of the corresponding air vent tube outlet 42.
It can be seen from an inspection of FIGS. 3 and 4, that two different configurations for the air vent tubes 28 and 38 have been depicted for purposes of illustration. The longer pair of vent tubes are identified by the reference numerals 28a and 28b while the shorter pair are numbered 38a and 38b. It should be noted that the air vent tube outlets 32 and 42 are positioned along the corresponding air venting reference lines 52 and 54 in both instances.
Assuming that the outer and inner container chambers 14 and 18, respectively, are filled with corresponding liquids 56 and 58, the liquids will be dispensed through the associated liquid discharge orifices 24 and 34 when the dispenser is tilted to a pouring position. If the dispenser is rotated or tilted downwardly toward the horizon line 50 in a vertical plane, as shown in FIGS. 3 and 4, the liquid in each of the air venting tubes will gradually move toward the air vent tube outlets 32 and 42. As the dispenser is tilted more, the liquid in each air vent tube continues to adjust its level until it reaches the same level as the other exposed free surface at the corresponding liquid discharge orifice. In trying to remain horizontally equal to the exposed free surface at the liquid discharge orifice, the exposed free surface in the air vent tube eventually drops low enough in the air vent tube to purge all of the liquid from the tube. Once this happens, the liquid seal is broken and air can now bubble up through the fluid and vent the interior of the container thereby allowing the free flow of liquid out of the container.
The breaking of the so-called "liquid seal" at the air vent tube outlets 32 and 42 occurs at the point at which the air venting reference lines 52 and 54 are horizontal, i.e., parallel to the horizon line 50. A slight further downward tilting of the dispenser so that the air venting reference lines are below the horizon 50, as shown in FIG. 4, will permit the free flow of liquid out of the dispenser. As long as the dispenser is tilted enough to locate the liquid discharge orifice below the corresponding air vent tube outlet, dispensing will continue. As the dispenser is returned back toward an upright position, the liquid, in an attempt to remain at an equal height, will re-enter the air venting tube thereby causing the formation of a liquid seal which prevents air venting of the interior of the container. With the air return thus cut off, dispensing of the two liquids will terminate.
The pouring threshold angle of the dispenser 10 can be controlled by varying the height relationship of the liquid discharge orifices and the corresponding air vent tube outlets. Looking at FIG. 3, the air vent tube outlets are located at a lower level than the respective liquid discharge orifices. This relationship dictates that the discharge orifices must be tilted below the horizon line 50 before dispensing will occur. If the discharge orifices and air tube outlets are at the same level, dispensing will occur when the dispenser is horizontal. In a similar fashion, dispensing can be made to occur before the dispenser reaches the horizontal by placing the air tube outlets above the corresponding liquid discharge orifices. This later arrangement is normally not desirable because the liquids have a tendency to "dribble" down the outside surface of the dispenser.
It will be appreciated from the preceding discussion that the regularity, i.e., constant discharge rate of liquid dispensing is achieved by utilizing the constant effect of gravity and by orienting the two containers with respect to a vertical plane so that when the dispenser is moved to a pouring position, gravity will equally affect the movement of the liquids contained within the two chambers. Given equal fill levels, the equal effect of gravity upon the liquids in the two chambers produces equal head pressures. The simultaneous venting of the two chambers is achieved by simultaneously breaking the liquid seals at the air tube outlets. This occurs when the two air venting reference lines 52 and 54 are (i) parallel to each other in a plane or (ii) are non-parallel to each other in a plane and the plane is perpendicular to the vertical plane when the dispenser is in a pouring position.
Since both of these configurations will satisfy the requirements for simultaneous venting which produces the concomitant simultaneous discharge of the liquids stored within the two chambers, it will be appreciated that a number of structural arrangements can be employed with regard to the relative positions of the containers 12 and 16. For example, the two containers can be positioned in a side-by-side arrangement with the handle 22 providing the proper orientation with respect to gravity for the user. Similarly, other shapes besides the generally cylindrical configuration for the chambers 14 and 18 can be used to achieve a desired packaging configuration.
The air vent tubes 28 and 38 can have a number of configurations, three of which are shown in the drawings. Preliminary experimental data indicates that the long, arcuate shaped tubes shown in FIGS. 1 and 2 of the drawings are less susceptible to liquid "stalling" than straight tubes either short or long. Apparently the air-liquid interface in the air vent tubes can move more easily when the air outlet end of the vent tube has an arcuate shape which approximately duplicates the arcuate, tilting movement of the dispenser in the vertical plane. However, it should be understood that the present invention is not limited to any specific air vent tube configuration and that certain design applications may make one configuration preferable over another. For example, if it is desirable to maintain the "liquid seal" at the air vent tube outlets until the liquids in the two chambers are almost completely exhausted, the vent tube outlets should be located close to the corresponding liquid discharge orifices. In this situation, an arrangement for the air vent tubes such as indicated in FIGS. 3 and 4 by the reference numerals 28b and 38b would be used.
It has already been mentioned that a variety of shapes can be employed for the liquid storage chambers 14 and 18. In order to achieve maximum metering accuracy with the generally cylindrical configuration illustrated in the drawings, the fill level of the two liquids within the chambers 14 and 18 should be the same as measured along the chamber axes when the axes are in a vertical plane.
A number of different materials can be used in the manufacture of the dispenser of the present invention. The preferred embodiment illustrated in FIG. 2 is shown constructed from plastic. However, it should be understood that the containers 12 and 16 can be made of glass or other materials. Preferably, the materials used for the construction of the containers 12 and 16 should have sufficient rigidity to resist vacuum deformation. Such rigidity insures that the containers will not flex or deform as the air is vented into the two chambers through the air venting systems 26 and 36.
Having described in detail a preferred embodiment of my invention it will now be apparent to those skilled in the art that numerous modifications can be made therein without departing from the scope of the invention as defined in the appended claims.
The present invention relates to liquid dispensers and more particularly, to a plural chambered, gravity oriented dispenser which provides an accurately metered, repeatable discharge of two or more liquids.
The art of plural chambered, liquid dispensers is relatively old and well developed. Representative examples of such pour type liquid dispensers are shown in British Pat. No. 505,875 and in the following U.S. Letters Pat. Nos. 2,438,906; 2,592,279; 2,661,870; 2,661,871; 2,665,816; 2,784,875; and 3,729,553. Among the dispensers described in the above listed patents, the Claudel dispenser, British Pat. No. 505,875, the Brink liquid dispenser No. 2,784,875 and the Heier variable-strength beverage dispenser No. 2,592,279 each depict a dispenser which provides for the variable ratio dispensing of two liquids. In the Heier variable-strength beverage dispenser air is vented into the liquid storage chambers through the liquid discharge orifice itself. In contrast, the dispensers shown in Brink and Claudel employ separate air returns to the liquid storage chambers. Although these patents disclose plural chambered, liquid dispensers which provide variable ratio dispensing of the liquids stored therein, the particular structures of these dispensers do not provide the requisite degree of metering accuracy and consistency which is desired for certain liquid dispensing applications.
It is accordingly a general object of the present invention to provide a plural chambered, liquid dispenser which dispenses two liquids at a predetermined ratio with extreme accuracy and consistency.
It is a specific object of the present invention to provide a plural chambered, liquid dispenser which utilizes a gravity response system to provide metering accuracy and consistency.
It is another object of the present invention to provide a plural chambered, liquid dispenser which has no moving parts and does not require special molding techniques.
It is still another object of the present invention to provide a plural chambered, liquid dispenser which consistently and accurately dispenses two or more liquids by utilizing a consistent orientation to gravity.
It is a feature of the present invention that the dispenser liquid containers can be fabricated inexpensively from a variety of materials including glass.
It is another feature of the invention that the dispenser is capable of dispensing over a wide range of predetermined dispensing ratios.
It is still another feature of the invention that the configuration of the dispenser automatically dictates to the user the correct pouring position for achieving simultaneous discharge of the liquids.
In the accomplishment of these objects, the preferred embodiment of the invention employs two rigid liquid containers, one positioned within the other and commonly attached to a large overcap. Each of the containers has a liquid metering orifice and an air return through the overcap. A common closure cap seals the air returns and the liquid orifices to close the containers and prevent cross contamination between the stored liquids. A pour handle is provided on the outer container to orient the dispenser to gravity during use. This guarantees that the force of gravity will always have the same effect on the dispensing performance of the dispenser.
To use the dispenser of the present invention the consumer removes the closure cap, grasps the handle and pours. As the dispenser is tipped, the two liquids approach their respective metering orifices. No liquid flows out of the dispenser until air is vented into each liquid containing chamber. Both of the liquid container air returns are designed in such a way as to be equally sensitive to the position of the dispenser. Once the consumer has tipped the dispenser beyond a predetermined threshold angle, air is simultaneously vented into each chamber and both liquids begin to pour in steady streams. As long as the consumer continues to pour, the two streams flow as a function of gravity and the size of the metering orifices. As soon as the dispenser is returned past the pouring threshold angle, the air returns stop venting air into the liquid containing chambers and dispensing terminates.
The objects and features of the present invention will best be understood from a detailed description of a preferred embodiment thereof selected for purposes of illustration and shown in the accompanying drawings, in which:
FIG. 1 is a perspective view of a plural chambered, gravity oriented dispenser constructed in accordance with the present invention;
FIG. 2 is a view in partial cross-section showing the dispenser of FIG. 1 with a modified pouring handle and a slightly different container configuration;
FIG. 3 is a diagrammatic view of a simplified dispenser constructed in accordance with the present invention which illustrates the relationships of the containers, liquid discharge orifices and air venting systems; and,
FIG. 4 is another view similar to that of FIG. 3 showing the dispenser thereof in the pouring position.
Turning now to the drawings, there is shown a dispenser constructed in accordance with the present invention and indicated generally by the reference numeral 10. The dispenser 10 comprises an outer container 12 which defines an outer chamber 14 which is adapted to contain a first liquid and an inner container 16 which defines a corresponding inner chamber 18 which is adapted to contain a second liquid. The two containers 14 and 16 are secured with respect to each other by means of a threaded overcap 20. The dispenser is provided with a handle 22 which may be separate from the overcap 20 as shown in FIG. 1 or formed as an integral part of the overcap as shown in FIG. 2.
The outer container 12 has a liquid discharge orifice 24 and an air venting system indicated generally by the reference numeral 26. The air venting system comprises an air vent tube 28 which is secured with respect to the outer container 12 and has an air inlet 30 which is in free communication with the atmosphere. The other end of the air vent tube 28 terminates in an air outlet 32 which is positioned within and in fluid communication with the outer container chamber 14. A similar structural arrangement is provided for the inner container 16 with a liquid discharge orifice 34 and an air venting system 36 comprising an air vent tube 38 with an inlet 40 and an air outlet 42 positioned within and in fluid communication with the inner container chamber 18. Preferably, the inner and outer chamber liquid discharge orifices 24 and 34 discharge into a common outlet 44 formed in an exteriorly threaded pour spout 46. The common outlet 44 is closed by means of a threaded closure cap 48 as shown in FIG. 1.
The operation of the plural chambered, gravity oriented liquid dispenser of the present invention can best be understood by reviewing first the liquid flow characteristics of a single dispenser and then analyzing the operation of the dual dispenser shown in the drawings with particular emphasis on the diagrammatic views of FIGS. 3 and 4.
Assuming that a liquid flow container has an unlimited free surface (upper surface is continuously exposed to atmospheric pressure) there are three dimensions that affect liquid flow from an orifice: the head (height of liquid directly above the orifice), the size of the orifice, and the cross sectional area of the free surface.
The first of these, the head, affects the velocity of flow. This can be easily observed when a bottle is poured at an angle of 45°. When full, the stream of liquid from the bottle will flow outward and downward and pour into a glass perhaps a foot from the bottle. As the bottle empties, the curve will become smaller until finally trickling straight down. This curve is an indication of the velocity of the flow and is dependent on the head. The formula for the velocity is V=√2gh, where g is the mathematical constant for acceleration due to gravity (equal to 980.62 cm/second 2 ) and h is the head (height of the liquid in centimeters).
The second dimension, orifice size, works in conjunction with velocity to describe the amount of liquid that is flowing. This is called discharge. Returning to the example of the bottle poured at a 45° angle, this second dimension, the area of the orifice, can be understood by placing a container at the end of the stream and collecting the discharge per second. It might be, arbitrarily, 0.3 in 3/sec. If the size of the orifice is now increased and the discharge collected again, one would find an increase in discharge in proportion to the amount one increased the size of the orifice. The formula for discharge is Q=A o √2gh where Q is the discharge and A o is the area of the orifice.
In theory, the area of the stream of a liquid is equal to the area of the orifice. In practice, it is less. Friction, viscosity, surface tension, etc., reduce the size of the stream and rate of velocity by a coefficient of discharge, C d which enters into the formula for discharge. Q a =C d A o √2gh is an equation more closely approximating practical experience. There are no rules for determining C d , it must be derived experimentally. Typically, for water dispensed from bottles and orifices of consumer dimensions, it is 0.88.
The third dimension, the cross-sectional area of the free surface defines (in conjunction with head) the volume of the liquid and affects the duration of discharge. For instance, if a wide round bottle and a narrow round bottle were both filled to the same height (equal head) the wide bottle would contain the greater volume of liquid as a function of its greater cross-sectional area (width). If both had the same orifice size, the wider bottle (with the greater amount of liquid) would discharge for a longer amount of time. Another example envisions two bottles, a wide round bottle and a narrow round bottle both filled with the same amount of liquid. The fill level of the narrow round bottle would obviously be higher. If both bottles had the same size orifice, the narrow bottle would discharge its liquid faster as a result of its greater head pressure. Hence, the same amount of liquid always flows out of tall, narrow bottles faster than shorter, wider bottles with the same size orifice. Tapered neck bottles take advantage of this fact by effectively speeding up flow in the lower head range by decreasing cross-sectional area (or actually increasing head per unit volume).
The formula for the time required to pour from height Y 1 , to height Y 2 is
t = - 1/C d A o √2g ∫ Y 2 /Y 1 A r Y - 1 /2 dy
When the bottle has a constant cross-section, the equation simplifies to
t = 2 A r /C d A o √2g (√Y 1 - √Y 2 )
Of the many variables that affect liquid flow, two variables, angle of pour and orifice configuration, are especially contributory to bottle performance. Pouring angle affects flow because head is a measure of the vertical component of a liquid column and it is shortened as the bottle axis approaches the horizon. Hence, velocity and, consequently, discharge rate increases as the bottle is tilted more towards vertical.
Another important variable is the shape of the orifice. There are critically engineered orifices that produce virtually no C d . For the present invention, an efficient design would include rounded metering entrances and short capillary tubes as opposed to normal orifices.
Up to this point, the discussion has focused on containers with unlimited free surfaces. Consumer pour bottles do not afford unlimited free surfaces and require some method of air replacement to allow pouring. Simple pour bottles return air through the liquid orifice causing the usual glub, glub sound and irregular pouring. To affect more consistent flow and/or to regulate the amount of flow, separate air returns are incorporated such as are often found on gasoline cans. Flow is still somewhat irregular with the separate air returns since the returning air must bubble through the liquid. A long tube attached to the air return can further improve flow by providing a direct, liquid-free air route to the air space in the container. These tubes, however, become partially filled with liquid when the bottle is sitting upright and care must be taken to prevent these tubes from becoming clogged with liquid when inverted. This situation is referred to as a stall because the clogged air return will not allow dispensing until it is cleared of liquid.
Control of orientation can prevent stalls by dictating that the air will always return through the air return and liquid will always flow unrestricted out the liquid orifice. One of the optimum relationships orientates the air return orifice above the liquid orifice when the dispenser tilts toward horizontal as shown in FIGS. 3 and 4. This orientation brings greater head pressure to bear on the liquid at the lower liquid orifice than on the liquid at the higher air orifice thus creating greater potential for flow for the lower orifice.
Dimensional relationships of the liquid and air orifices additionally dictate flow direction. For instance, the liquid orifice should be larger than the air orifice to provide greater potential for liquid flow out of the liquid orifice. This relationship is improved by the head pressure differential provided by proper orientation as explained above.
Since air return dispensing threshold is a requirement for liquid dispensing, flow of liquid can be initiated and ceased by controlling the air return system. The air return sequence to a bottle with an air return tube can be explained with reference to the siphon. All exposed free surfaces of a body of liquid attempt to remain at equal heights and any situation which causes an imbalance will cause flow to equalize the fluid levels. Sitting upright, such a container has two exposed liquid free surfaces, the liquid in the container exposed to atmosphere by the open liquid orifice, and the liquid in the air return tube exposed to atmosphere by the air orifice. The liquid in the air return tube is at the same height as the liquid in the bottle (actually the liquid in the air return tube often is a little higher due to an unrelated phenomenon -- capillary action). When the bottle is tilted to pour, the liquid level changes to approach the liquid orifice. The liquid in the air return tube also changes to adjust for the new liquid level.
As the bottle is tilted more, the liquid covers the liquid orifice isolating the formerly free surface from the atmosphere and entrapping it within the interior of the container. The liquid covering the orifice becomes the exposed free surface. As the bottle is tilted further, the liquid in the air return tube continues to adjust until it reaches the same level as the liquid at the orifice. At some point, the liquid in the air return tube, in seeking to continue reaching equilibrium, completely evacuates the air return tube. Air now has uninhibited communication with the interior of the bottle venting atmospheric pressure and allowing the free flow of liquid out of the container.
The previous dual dispensing discussion has described force of gravity, its effect on discharge, the need of air replacement and various ways to control the air return to regulate and initiate flow. The simplest form of dual dispensing would be to take two bottles of the same height and cross-sectional configuration and fit them each with a cap with the same orifice size and same length and size air return tubes. If both were filled to the same level, orientated with the air returns over the liquid orifices and simultaneously inverted, one would have a simple 1:1 co-dispenser.
If a 3:1 simple co-dispenser is desired, one bottle is replaced with another bottle that has three times the cross-sectional area and an orifice adjusted for three times the volume flow. With height remaining the same, the duration of discharge would be the same for both, but the wider bottle, with the larger orifice, would discharge three times the amount of liquid. In order to control the simultaneous flow of the liquids, the two bottles are similarly orientated and attached each to each other and to a handle. If both air returns are of the same length and angle in relationship to their liquid orifice, tipping the filled bottles to threshold will cause simultaneous dispensing.
Looking now at FIGS. 3 and 4, the dispenser 10 is shown diagrammatically in FIG. 3 in a non-pouring position with the axes of the inner and outer chambers parallel to a horizon line 50 and in FIG. 4 with the chamber axes positioned below the horizon line 50. The horizon 50 is perpendicular to a vertical plane which contains the gravity vector. For purposes of this application, the term "vertical plane" shall mean a plane which is vertical to the earth's surface and which contains the gravity vector. The horizon line 50 represents the earth's surface and is, of course, perpendicular to the "vertical plane."
In addition to the container axes and the horizon line 50, the diagrammatic views of FIGS. 3 and 4 also include two air venting reference lines 52 and 54. Air venting reference line 52 is defined by the two points of the center of the outer container liquid discharge orifice 24 and the center of outer container air vent tube outlet 32. The other air venting reference line 54 is similarly defined by the center of the inner container liquid discharge orifice 34 and the center of the corresponding air vent tube outlet 42.
It can be seen from an inspection of FIGS. 3 and 4, that two different configurations for the air vent tubes 28 and 38 have been depicted for purposes of illustration. The longer pair of vent tubes are identified by the reference numerals 28a and 28b while the shorter pair are numbered 38a and 38b. It should be noted that the air vent tube outlets 32 and 42 are positioned along the corresponding air venting reference lines 52 and 54 in both instances.
Assuming that the outer and inner container chambers 14 and 18, respectively, are filled with corresponding liquids 56 and 58, the liquids will be dispensed through the associated liquid discharge orifices 24 and 34 when the dispenser is tilted to a pouring position. If the dispenser is rotated or tilted downwardly toward the horizon line 50 in a vertical plane, as shown in FIGS. 3 and 4, the liquid in each of the air venting tubes will gradually move toward the air vent tube outlets 32 and 42. As the dispenser is tilted more, the liquid in each air vent tube continues to adjust its level until it reaches the same level as the other exposed free surface at the corresponding liquid discharge orifice. In trying to remain horizontally equal to the exposed free surface at the liquid discharge orifice, the exposed free surface in the air vent tube eventually drops low enough in the air vent tube to purge all of the liquid from the tube. Once this happens, the liquid seal is broken and air can now bubble up through the fluid and vent the interior of the container thereby allowing the free flow of liquid out of the container.
The breaking of the so-called "liquid seal" at the air vent tube outlets 32 and 42 occurs at the point at which the air venting reference lines 52 and 54 are horizontal, i.e., parallel to the horizon line 50. A slight further downward tilting of the dispenser so that the air venting reference lines are below the horizon 50, as shown in FIG. 4, will permit the free flow of liquid out of the dispenser. As long as the dispenser is tilted enough to locate the liquid discharge orifice below the corresponding air vent tube outlet, dispensing will continue. As the dispenser is returned back toward an upright position, the liquid, in an attempt to remain at an equal height, will re-enter the air venting tube thereby causing the formation of a liquid seal which prevents air venting of the interior of the container. With the air return thus cut off, dispensing of the two liquids will terminate.
The pouring threshold angle of the dispenser 10 can be controlled by varying the height relationship of the liquid discharge orifices and the corresponding air vent tube outlets. Looking at FIG. 3, the air vent tube outlets are located at a lower level than the respective liquid discharge orifices. This relationship dictates that the discharge orifices must be tilted below the horizon line 50 before dispensing will occur. If the discharge orifices and air tube outlets are at the same level, dispensing will occur when the dispenser is horizontal. In a similar fashion, dispensing can be made to occur before the dispenser reaches the horizontal by placing the air tube outlets above the corresponding liquid discharge orifices. This later arrangement is normally not desirable because the liquids have a tendency to "dribble" down the outside surface of the dispenser.
It will be appreciated from the preceding discussion that the regularity, i.e., constant discharge rate of liquid dispensing is achieved by utilizing the constant effect of gravity and by orienting the two containers with respect to a vertical plane so that when the dispenser is moved to a pouring position, gravity will equally affect the movement of the liquids contained within the two chambers. Given equal fill levels, the equal effect of gravity upon the liquids in the two chambers produces equal head pressures. The simultaneous venting of the two chambers is achieved by simultaneously breaking the liquid seals at the air tube outlets. This occurs when the two air venting reference lines 52 and 54 are (i) parallel to each other in a plane or (ii) are non-parallel to each other in a plane and the plane is perpendicular to the vertical plane when the dispenser is in a pouring position.
Since both of these configurations will satisfy the requirements for simultaneous venting which produces the concomitant simultaneous discharge of the liquids stored within the two chambers, it will be appreciated that a number of structural arrangements can be employed with regard to the relative positions of the containers 12 and 16. For example, the two containers can be positioned in a side-by-side arrangement with the handle 22 providing the proper orientation with respect to gravity for the user. Similarly, other shapes besides the generally cylindrical configuration for the chambers 14 and 18 can be used to achieve a desired packaging configuration.
The air vent tubes 28 and 38 can have a number of configurations, three of which are shown in the drawings. Preliminary experimental data indicates that the long, arcuate shaped tubes shown in FIGS. 1 and 2 of the drawings are less susceptible to liquid "stalling" than straight tubes either short or long. Apparently the air-liquid interface in the air vent tubes can move more easily when the air outlet end of the vent tube has an arcuate shape which approximately duplicates the arcuate, tilting movement of the dispenser in the vertical plane. However, it should be understood that the present invention is not limited to any specific air vent tube configuration and that certain design applications may make one configuration preferable over another. For example, if it is desirable to maintain the "liquid seal" at the air vent tube outlets until the liquids in the two chambers are almost completely exhausted, the vent tube outlets should be located close to the corresponding liquid discharge orifices. In this situation, an arrangement for the air vent tubes such as indicated in FIGS. 3 and 4 by the reference numerals 28b and 38b would be used.
It has already been mentioned that a variety of shapes can be employed for the liquid storage chambers 14 and 18. In order to achieve maximum metering accuracy with the generally cylindrical configuration illustrated in the drawings, the fill level of the two liquids within the chambers 14 and 18 should be the same as measured along the chamber axes when the axes are in a vertical plane.
A number of different materials can be used in the manufacture of the dispenser of the present invention. The preferred embodiment illustrated in FIG. 2 is shown constructed from plastic. However, it should be understood that the containers 12 and 16 can be made of glass or other materials. Preferably, the materials used for the construction of the containers 12 and 16 should have sufficient rigidity to resist vacuum deformation. Such rigidity insures that the containers will not flex or deform as the air is vented into the two chambers through the air venting systems 26 and 36.
Having described in detail a preferred embodiment of my invention it will now be apparent to those skilled in the art that numerous modifications can be made therein without departing from the scope of the invention as defined in the appended claims.