U.S. patent application number 11/680726 was filed with the patent office on 2007-10-11 for liquid dispenser including regulator device.
Invention is credited to M. Edmund Ellion.
Application Number | 20070235476 11/680726 |
Document ID | / |
Family ID | 38574098 |
Filed Date | 2007-10-11 |
United States Patent
Application |
20070235476 |
Kind Code |
A1 |
Ellion; M. Edmund |
October 11, 2007 |
LIQUID DISPENSER INCLUDING REGULATOR DEVICE
Abstract
A fluid dispenser has a fluid outlet and an ambient inlet. The
dispenser includes a container having a cavity, and a regulator
device within the container cavity for regulating liquid flow out
of the fluid outlet. The regulator device has a cavity in fluid
communication with the ambient inlet, and an air transfer orifice
for placing the device cavity in fluid communication with the
container cavity. The air transfer orifice is spaced apart from the
ambient inlet. The regulator device also has a fluid inlet.
Location of the air transfer orifice with respect to the fluid
inlet is such that flow of liquid from the container cavity into
the device cavity stops when the liquid in the device cavity
reaches the air transfer orifice.
Inventors: |
Ellion; M. Edmund; (Santa
Ynez, CA) |
Correspondence
Address: |
HUGH P. GORTLER
23 ARRIVO DRIVE
MISSION VIEJO
CA
92692
US
|
Family ID: |
38574098 |
Appl. No.: |
11/680726 |
Filed: |
March 1, 2007 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
60744404 |
Apr 6, 2006 |
|
|
|
Current U.S.
Class: |
222/456 ;
222/442 |
Current CPC
Class: |
B65D 23/04 20130101;
G01F 11/262 20130101 |
Class at
Publication: |
222/456 ;
222/442 |
International
Class: |
G01F 11/26 20060101
G01F011/26; G01F 11/28 20060101 G01F011/28 |
Claims
1. A fluid dispenser having a fluid outlet and an ambient inlet,
the dispenser comprising: a container having a cavity; and a
regulator device within the container cavity for regulating liquid
flow out of the fluid outlet, the regulator device having a cavity
in fluid communication with the ambient inlet, the regulator device
having an air transfer orifice for placing the device cavity in
fluid communication with the container cavity, the air transfer
orifice spaced apart from the ambient inlet, the regulator device
also having a fluid inlet, wherein location of the air transfer
orifice with respect to the fluid inlet is such that flow of liquid
from the container cavity into the device cavity stops when the
liquid in the device cavity reaches the air transfer orifice,
whereby the flow into the device cavity stops when pressure on both
sides of the fluid inlet are equal.
2. The fluid dispenser of claim 1, wherein the fluid inlet is
proximate to the fluid outlet, and wherein liquid flow out of the
fluid outlet is stopped when liquid in the device cavity reaches
the air transfer orifice, whereby dispensing time is regulated.
3. The fluid dispenser of claim 2, wherein container-side pressure
at the fluid outlet during dispensing is a function of pressure at
the air transfer passageway and fluid height between the fluid
inlet and the air transfer orifice.
4. The apparatus of claim 2, further comprising a closure for the
container, the regulator device carried by the closure.
5. The dispenser of claim 5, wherein the regulator device includes
a base and sidewall that define the device cavity, the base
opposing the closure, the air transfer orifice in the base, the
fluid inlet in the sidewall.
6. The dispenser of claim 1, wherein the regulator device includes
a tube having a first end outside of the container and a second end
extending into the container, the first end of the tube being open
and functioning as both the fluid outlet and the ambient inlet; and
wherein the tube includes a trap portion for trapping liquid
between the liquid inlet and the air transfer orifice; whereby
dispensing volume is regulated.
7. The dispenser of claim 6, wherein the second end of the tube is
partially closed and proximate to a base of the container, and
wherein the fluid inlet and air transfer orifice are in the tube,
with the air transfer orifice being between the fluid inlet and the
open end of the tube.
8. The dispenser of claim 6, wherein the second end of the tube is
also open and functions as the fluid inlet, wherein the tube has a
second trap portion, and wherein the air transfer orifice is
intermediate the fluid inlet and the second trap portion, wherein
liquid is captured between the fluid inlet and the air transfer
orifice when the dispenser is in a first orientation, and wherein
the trapped liquid is transferred to the second trap portion when
the dispenser is in a second orientation.
9. An article for a container of a liquid dispenser, comprising: a
closure for the container; and a regulator device, carried by the
closure, for regulating liquid flow out of a fluid outlet, the
regulator having a cavity in fluid communication with an ambient
inlet, the regulator device having an air transfer orifice for
placing the device cavity in fluid communication with a cavity of
the container, the air transfer orifice spaced apart from the
ambient inlet, the regulator device also having a fluid inlet
proximate to the fluid outlet, wherein location of the air transfer
orifice with respect to the fluid inlet is such that flow of liquid
from the container cavity into the device cavity stops when the
liquid reaches the air transfer orifice.
10. An article for a container of a liquid dispenser, comprising: a
closure for the container; and a regulator device, secured to the
closure, for regulating liquid flow out of a fluid outlet, the
regulator having a cavity in fluid communication with an ambient
inlet, the regulator device including a tube having a first end
outside of the container and a second end extending into the
container, the first end being open and functioning as both the
fluid outlet and the ambient inlet, the tube having an air transfer
orifice and a fluid inlet for placing the device cavity in fluid
communication with a cavity of the container, wherein the tube
includes a trap portion between the fluid inlet and air transfer
orifice for trapping liquid without a valve.
11. The article of claim 10, wherein the second end of the tube is
partially closed, and wherein the fluid inlet and air transfer
orifice are in the tube, with the air transfer orifice being
between the fluid inlet and the open end of the tube.
12. The article of claim 10, wherein the second end of the tube is
also open and functions as the fluid inlet, wherein the tube has a
second trap portion, and wherein the air transfer orifice is
intermediate the fluid inlet and the second trap portion, wherein
liquid is captured between the fluid inlet and the air transfer
orifice in a first orientation, and wherein the trapped liquid is
transferred to the second trap portion in a second orientation.
13. The article of claim 10, wherein the tube has a fluid passage
from the fluid inlet to the fluid outlet, and wherein the fluid
passage is unobstructed.
14. The article of claim 10, wherein the fluid inlet and the air
transfer orifice define the trap portion.
Description
BACKGROUND
[0001] FIG. 1a illustrates a closed container 10 with a small
discharge orifice 14 containing liquid 11. The pressure of the air
12 in the container 10 is equal to atmospheric pressure P.sub.o.
The pressure in the liquid 11 at any depth increases from the value
of the air pressure at the surface level 13 of the liquid 11 by an
amount equal to the density of the liquid times the vertical
distance below the surface 13 of the liquid 11. This pressure
distribution is illustrated in FIG. 2 for the container 10 when the
container 10 is inverted and the orifice 14 is blocked. If the
container 10 is inverted and if the liquid 11 is water, an orifice
diameter of less than 0.2 inches will prevent atmospheric air from
entering the container 10 through the orifice 14. Since the
pressure of the liquid 11 increases by an amount equal to the
density (d) of the liquid 11 times the depth below the surface 13,
it should be noted that the difference in the liquid pressure from
the depth h.sub.1 to the depth h.sub.2 is equal to the product of
the density times the vertical distance between h.sub.1 and h.sub.2
and is independent of the pressure of the air (Pair) or the amount
of liquid 11 in the container 10.
[0002] FIG. 1b illustrates the container 10 when it is inverted and
the small discharge orifice 14 is located a vertical distance
H.sub.1 below the surface 13 of the liquid 11. Since the air
pressure in the container 10 is at atmospheric P.sub.o, the
pressure of the liquid at the discharge orifice 14 is greater than
the atmospheric pressure by the product of the liquid density (d)
times the vertical distance (H.sub.1) below the surface 13 of the
liquid. That is, P=P.sub.o+dH.sub.1, where P is the pressure on the
container-side of the discharge orifice 14. This added pressure
causes liquid 11 to flow out of the container 10 to the atmosphere
through the discharge orifice 14. As liquid 11 flows out of the
container 10, the volume of the air 12 in the container 10
increases causing the pressure of the air 12 within the container
10 to decrease. The flow of liquid 11 through the discharge orifice
14 continues until the pressure (Pair) of the air 12 in the
container 10 decreases to a value equal to the atmospheric pressure
P.sub.o minus the product of the density of the liquid times the
vertical distance the discharge orifice 14 is below the surface 13
of the liquid 11. When the pressure of the liquid at the container
side of the discharge orifice 14 equals the atmospheric pressure
P.sub.o, the flow of liquid stops as illustrated in FIG. 1c. It
should be noted that the volume of the liquid 11 flowing out of the
container is not constant since it depends on the level of the
liquid 11 in the container 10 as well as the volume of the air 12
in the container 10.
[0003] FIGS. 3a, 3b and 3c illustrate three containers 10 having
vent tubes of three distinct lengths. Each container 10 also has a
small discharge orifice 14. FIG. 3a illustrates a container 10 with
a vent tube 31 that is in fluid communication with the atmosphere
and the interior of the container 10. FIG. 3a also illustrates the
container 10 in an inverted orientation. When liquid is discharged
through the discharge orifice 14, the pressure in the container 10
tends to decrease. When the pressure of the liquid at the exit 32
of the vent tube 31 decreases to slightly below atmospheric, air 33
from the atmosphere enters the container 10 through the vent tube
31. This air 33 replaces the liquid that is discharged and the
pressure of the liquid in the container remains constant
thereafter. The result is that the pressure at the discharge
orifice 14 is maintained above atmospheric since it is below the
level of exit 32 and the liquid continues to be discharged. This
discharge would occur until the container 10 is empty of
liquid.
[0004] FIG. 3b illustrates a container 10 with a shorter vent tube
34. In this container 10, the pressure must decrease to atmospheric
at the exit 35 of the vent tube 34 before air can enter the
container 10 and maintain the pressure of the liquid constant.
Since the vent tube 34 is shorter, there is less liquid between the
exit 35 of the vent tube 34 and the discharge orifice 14. As a
result the pressure at the discharge orifice 14 is lower than it
was with the longer vent tube 31 and the discharge rate of liquid
is lower. However, the discharge of liquid will still continue
until the container 10 is empty of liquid.
[0005] FIG. 3c illustrates a container 10 with a zero length vent
tube (just an orifice 14). In this case the liquid is discharged
until the liquid pressure at the orifice 14 decreases to
atmospheric. Only a small percent of the liquid contents of the
container 10 is discharged.
[0006] It would be desirable for a liquid dispenser to have a vent
tube that can change its length automatically to decrease the
discharge flow rate so that the tube length becomes zero when a
desired volume of liquid is discharged and the flow stops.
[0007] It would also be desirable to realize this effect without
any moving parts.
[0008] In certain situations, it would also be desirable to
dispense a measured volume of liquid.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIGS. 1a, 1b and 1c are illustrations of a conventional
closed container with a small discharge orifice
[0010] FIG. 2 is an illustration of pressure in liquid in the
container of FIGS. 1a, 1b and 1c.
[0011] FIGS. 3a, 3b, and 3c are illustrations of conventional
closed containers with vent tubes of different lengths.
[0012] FIG. 4a is an illustration of a liquid dispenser according
to an embodiment of the present invention.
[0013] FIGS. 4b and 4c are illustrations of a regulator device in
accordance with embodiments of the present invention.
[0014] FIGS. 5a-5d illustrate the operation of a regulator device
in accordance with an embodiment of the present invention.
[0015] FIGS. 6a-6d are illustrations of functional equivalents of
the device of FIGS. 5a-5d.
[0016] FIGS. 7a-7d illustrate the principles of operation of liquid
dispensers illustrated in FIGS. 8a-8d, 9 and 10.
[0017] FIGS. 8a-8d are illustrations of a liquid dispenser
according to an embodiment of the present invention.
[0018] FIG. 9 is an illustration of a liquid dispenser according to
an embodiment of the present invention.
[0019] FIG. 10 is an illustration of a liquid dispenser according
to an embodiment of the present invention.
DETAILED DESCRIPTION
[0020] Reference is made to FIG. 4a, which illustrates a liquid
dispenser 40 in an upright position. The liquid dispenser 40
includes a container 42 having a cavity 49, a closure 45 for the
container 42, and a regulator device 41 within the container cavity
49. In a first embodiment of the liquid dispenser 40a, as shown in
FIG. 4b, the closure 45 has an air inlet orifice 46 and a liquid
discharge orifice 47. In a second embodiment of the liquid
dispenser 40b, as shown in FIG. 4c, the regulator device 41 has the
air inlet orifice 46 instead of the closure 45. In both
embodiments, the regulator device 41 has a cavity 48, an air
transfer orifice 43 and a device liquid inlet orifice 44.
[0021] When the liquid dispenser 40 is oriented in an upright
position, as shown in FIG. 4a, any liquid in the device cavity 48
drains back into the container cavity 49 through the air transfer
orifice 43. The air inlet orifice 46 admits atmospheric air into
the device cavity 48. The air transfer orifice 43 admits air into
the container cavity 49 from the device cavity 48. The pressures in
the upright liquid dispenser 40 are as follows: [0022] Air in the
device cavity 48=Atmosphere (P.sub.o). [0023] Air at the air
transfer orifice 43=Atmosphere (P.sub.o). [0024] Liquid at the air
transfer orifice 43=Atmosphere (P.sub.o). [0025] Liquid at the
device liquid inlet orifice 44 and the liquid discharge orifice 47
equal atmosphere plus the liquid density times the liquid level
between the air transfer orifice 43 and the liquid discharge
orifice 47 (P.sub.o+dh.sub.1). [0026] Air at the air inlet orifice
46=Atmosphere (P.sub.o).
[0027] It will be instructive to describe a simplified
configuration before describing the actual design. The
simplification is based on the following assumptions: (1) zero
pressure drop across any of the four orifices, (2) the device 41 is
inverted from upright, (3) the vertical height of liquid between
the air inlet orifice 46 and the liquid discharge orifice 47 is
negligible and (4) the liquid pressure at the air transfer orifice
43 has decreased to atmospheric at the start of this
discussion.
[0028] When the container 42 is inverted, sufficient liquid has
been withdrawn from the container 42 to reduce the pressure of the
liquid at the air transfer orifice 43 to atmospheric P.sub.o as
illustrated in FIG. 5a.
[0029] FIG. 5a illustrates the regulator device 41 inverted from
the upright orientation. At this orientation, it the regulator
device 41 is immersed in liquid from the container 42.
[0030] As soon as the liquid dispenser 40 is inverted and the
regulator device 41 becomes immersed in liquid, the pressure at the
air transfer orifice 43 is greater than atmospheric. Consequently,
fluid flows into the device cavity 48 through the air transfer
orifice 43 until the pressure at the air transfer orifice 43
decreases below that in the device cavity 48.
[0031] The head of liquid in the container cavity 49 between the
air transfer orifice 43 and the device liquid inlet orifice 44
causes the pressure of the liquid at the device liquid inlet
orifice 44 and the liquid discharge orifice 47 to be greater than
atmospheric. As a result liquid is discharged through the liquid
discharge orifice 47 and liquid flows into the device cavity 48
through the liquid inlet orifice 44 as illustrated in FIG. 5b. The
pressure in the device cavity 48 reduces to the value of
atmospheric minus the liquid head in the device cavity 48
(P.sub.o-dh.sub.2). As liquid is discharged, the pressure of the
liquid in the container 42 at the air transfer orifice 43 is
reduced, causing a reduction in the discharge rate. This reduction
of pressure also causes air in the cavity 48 to flow into the
container 42 through the air transfer orifice 43 to maintain the
pressure therein and the discharge continues.
[0032] Liquid continues to flow into the device cavity 48 through
the device liquid inlet orifice 44, and liquid continues to be
discharged through the liquid discharge orifice 47 until the device
cavity 48 becomes full of liquid as illustrated in FIG. 5d. At that
time, the pressure at the air transfer orifice 43 equals
P.sub.o-dh.sub.4 and the pressure at the liquid discharge orifice
47 equals P.sub.o-dh.sub.4+dh.sub.1. Since dh.sub.1=dh.sub.4, the
pressure at the device liquid inlet orifice 44 and the liquid
discharge orifice 47 equal atmospheric P.sub.o, so all flow out of
orifice 47 stops. It should be noticed that the pressure at the
liquid discharge orifice 47 depends only on the pressure at the air
transfer orifice 43 and the vertical distance between the air
transfer orifice 43 and the liquid discharge orifice 47. The volume
of the discharged liquid is controlled by the size of the liquid
inlet orifice 44, the pressure at the liquid discharge orifice 47
and the time it takes to fill the device cavity 48 with liquid. The
discharge is seen to be independent of the amount of air and liquid
in the container 42.
[0033] A fixed volume is discharged through the liquid discharge
orifice 47 because of the following conditions: [0034] (1) The rate
of flow of the discharged liquid is controlled by the size of the
liquid discharge orifice 47 and the pressure difference between the
liquid at the liquid discharge orifice 47 and the atmosphere.
[0035] (2) The pressure at the liquid discharge orifice 47 is
controlled by the pressure at the air transfer orifice 43 and the
height of the liquid between the two orifices 43 and 47. [0036] (3)
The pressure at the air transfer orifice 43 is controlled by the
pressure in the device cavity 48. [0037] (4) The pressure within
the device cavity 48 is controlled by the liquid level in the
device cavity 48. [0038] (5) The liquid level in the device cavity
48 is controlled by the size of the device liquid inlet orifice 44
and the volume of the device cavity 48.
[0039] Thus, the regulator device 41 is functionally equivalent to
a variable length vent tube. This becomes apparent from a
comparison of the device in FIGS. 5a-5d to its functional
equivalents in FIGS. 6a-6d. The small pressure drop through the
orifice will be neglected in this comparison.
[0040] Reference is once again made to FIG. 5a. Sufficient liquid
has been discharged from the container 42 so that the liquid at the
air transfer orifice 43 is at the pressure of the atmosphere. Since
the air in the cavity 48 is at atmospheric, there is no pressure
difference, so air in the cavity 48 does not flow through the air
transfer orifice 43 or the air inlet orifice 46. The pressures at
the device liquid inlet orifice 44 and the liquid discharge orifice
47 are greater than at the air transfer orifice 43 and therefore
greater than atmospheric due to the head of liquid (h.sub.1). As a
result, liquid flows into the device cavity 48 through the liquid
inlet orifice 44, and it flows out of the container 42 through the
liquid discharge orifice 47.
[0041] The pressure of the liquid at the air transfer orifice 43
equals P=P.sub.o and the pressure at the liquid discharge orifice
47 equals
P=P.sub.o+dh.sub.1 (1)
where P.sub.o is the atmospheric pressure, d is the density of the
liquid, and h.sub.1 is the height of the liquid between the air
transfer orifice 43 and the liquid discharge orifice 47.
[0042] The functional equivalent of FIG. 5a is illustrated in FIG.
6a. FIG. 6a illustrates a container 10 with a long vent tube 31.
The pressure of the liquid at the exit 32 to the vent tube 31
equals P.sub.o and the pressure at the discharge orifice 14
equals
P=P.sub.o+dH.sub.1. (2)
where P.sub.o is the atmospheric pressure, d is the density of the
liquid, and H.sub.1 is the vertical height of the liquid between
the vent tube exit 32 and the discharge orifice 14.
[0043] It is seen by comparing equation 1 with equation 2 that the
pressure at the liquid discharge orifice 47 and discharge orifice
14 are the same if h.sub.1=H.sub.1 As a result the discharge rate
will be the same if the size of the liquid discharge orifice 47
also equals the size of the discharge orifice 14.
[0044] FIG. 5b illustrates the regulator device 41 after additional
liquid has flowed into the device cavity 48. FIG. 6b illustrates
the functional equivalent, which has a shorter vent tube 34 than
the vent tube of FIG. 6a. The pressure of the air in the device
cavity 48 equals P.sub.o-dh.sub.2 the pressure of the liquid at the
air transfer orifice 43 equals P.sub.o-dh.sub.2 and the pressure at
the liquid discharge orifice 47 equals
P.sub.o-dh.sub.2+dh.sub.1.
[0045] Reference is made to FIG. 5c, which illustrates the
regulator device 41 after more liquid has flowed into the device
cavity 48. The pressure of the air in the device cavity 48 equals
P.sub.o-dh.sub.3, the pressure of the liquid at the air transfer
orifice 43 equals P=P.sub.o-dh.sub.3 and the pressure at the liquid
discharge orifice 47 equals
P=P.sub.o-dh.sub.3+dh.sub.1 (3)
where P.sub.o is the atmospheric pressure, d is the density of the
liquid, h.sub.1 is the vertical height between the air transfer
orifice 43 and the liquid discharge orifice 47, and h.sub.3 is the
vertical height of the liquid in the device cavity 48.
[0046] The functional equivalent of FIG. 5c is illustrated in FIG.
6c. FIG. 6c illustrates a container 10 with a shorter vent tube 36
than the vent tube 31 in FIG. 6a. Sufficient liquid has been
removed from the container 10 so that the pressure of the liquid at
the exit 37 to the vent tube 36 equals P.sub.o and the pressure at
the discharge orifice 14 equals
P=P.sub.o+dH.sub.3 (4)
where P.sub.o is the atmospheric pressure, d is the density of the
liquid, H.sub.3 is the height of the liquid between the vent tube
exit 37 and the discharge orifice 14.
[0047] Equation (4) becomes
P=P.sub.o-d.DELTA.h+dH.sub.1 (5)
where .DELTA.h is the difference in the vertical length of the long
and short vent tubes. That is, .DELTA.h=H.sub.1-H.sub.3.
[0048] Examination of equation (3) and (5) shows that the pressures
at the discharge orifices have similar relations. As a result the
flow rate discharges are equal if .DELTA.h=h.sub.3, if
H.sub.1=h.sub.1, and if the discharge orifices 47 and 14 are of
equal size.
[0049] Reference is made to FIG. 5d, which illustrates the
regulator device 41 when the device cavity 48 is full of liquid.
The pressure of the liquid at the air transfer orifice 43 equals
P=P.sub.o-dh.sub.4 and the pressure at the liquid discharge orifice
47 equals
P=Po-dh.sub.4+dh.sub.1 (6)
where P.sub.o is the atmospheric pressure, d is the density of the
liquid, h.sub.1 is the height of the liquid between the air
transfer orifice 43 and the liquid discharge orifice 47, and h4 is
the height of the liquid in the device cavity 48.
[0050] Since the device cavity 48 is full of liquid,
(h.sub.4=h.sub.1) and equation (6) becomes
P=P.sub.o. (7)
[0051] The functional equivalent of FIG. 5d is illustrated in FIG.
6d. FIG. 6d illustrates a container with a vent tube of zero length
34 (just an orifice). Sufficient liquid has been removed from the
container so that the pressure of the liquid at the orifice 14
equals
P=P.sub.o (8)
where P.sub.o is the atmospheric pressure.
[0052] It is seen by equations (7) and (8) that the pressures at
the discharge orifices 47 and 14 are equivalent. If the size of the
discharge orifices 47 and 14 are also equal, the liquid discharge
flow rates are also equal.
[0053] Thus, the regulator device 41 effectively operates as a
variable length vent tube. The level of the liquid in the device
cavity 48 below the orifice 43 produces the same effect on the
liquid discharge rate as vent tubes of different lengths. Yet the
vent device 41 effectively operates in such a manner without any
moving parts.
[0054] The device 41 also functions to dispense liquid over a
constant interval of time. The rate of liquid discharged from the
container through the liquid discharge orifice 47 is controlled by
the liquid pressure at the liquid discharge orifice 47 and the size
of the liquid discharge orifice 47. The pressure at the liquid
discharge orifice 47 is controlled by the size of the device cavity
48, the rate at which atmospheric air is admitted to the device
cavity 48 through the air inlet orifice 46 and then to the
container 42 through the air transfer orifice 43. The rate at which
atmospheric air is admitted to the device cavity 48 is controlled
by the size of the air inlet orifice 46 and the pressure in the
device cavity 48. The pressure in the device cavity 48 is
controlled by the rate at which liquid is admitted to the device
cavity 48 through the device liquid inlet orifice 44.
[0055] When the container 42 is inverted, liquid is discharged from
the container 42 through the liquid discharge orifice 47 and other
liquid enters the device cavity 48 through the device liquid inlet
orifice. As a result, the pressures in the container 42 and the
device cavity 48 are reduced. This reduction allows air from the
atmosphere to flow into the device cavity 48 through the air inlet
orifice 46 and then into the container 42 through the air transfer
orifice 43. This airflow keeps the pressure at the fluid discharge
orifice above atmospheric and liquid continues to be discharged.
Simultaneously, liquid from the container 42 continues to flow into
the device cavity 48 through the device liquid inlet orifice 44.
The resulting head of liquid in the device cavity 48 restricts the
rate at which air enters the device cavity 48. Thus, the pressure
in the device cavity 48 and the container 42 is reduced. Because of
the lower pressure, the discharge rate of liquid is reduced. When
the head of liquid in the device cavity 48 is great enough to stop
the flow of air into the device cavity 48 and then into the
container 42, the pressure at the liquid discharge orifice reduces
to atmospheric and the discharge stops. This occurs when liquid
reaches the air transfer orifice 43. The volume of the discharge is
controlled by the liquid pressures at the liquid discharge orifice
47, the size of the liquid discharge orifice 47 and the time that
it takes for the device cavity 48 to fill with liquid.
[0056] In order to increase the discharge volume, the device liquid
inlet orifice 44 could be decreased to increase the time to fill
the regulator device 41 or the volume of the regulator device 41
could be increased. Another way to increase the volume of the
discharge is to increase the rate of discharge by increasing the
liquid discharge orifice 47.
[0057] The volume of the dispensed liquid varies by about .+-.3% as
determined by experiment. This variation should be sufficient for
certain applications, such as coffee cream dispensers, liquor
dispensers, adding concentrated liquids to dilatants, etc.
[0058] The regulator device of FIG. 4a regulates the time during
which liquid flows out of the liquid dispenser 40. However, a
regulator device according to the present invention is not so
limited. FIGS. 8-10 illustrate regulator devices that regulate the
volume of captured liquid, which is then dispensed through a fluid
outlet. Before describing the embodiments in FIGS. 8-10, their
principle of operation will be described. The principle of
operation will be described in connection with FIGS. 7a-7d.
[0059] Reference is now made to FIG. 7a, which shows a vessel 70
with a vent 71 and an entrance 72. The vessel 70 contains a liquid
73 at a level H.sub.1 above the vent 71, which is in fluid
communication with a holding volume 74. The holding volume 74 is in
fluid communication with the atmosphere through the opening 75 so
that the air pressure therein remains at atmospheric. Additionally,
the entrance 72 in the holding volume 74 is in liquid communication
with the liquid 73 in the vessel 70.
[0060] Initially, the pressure of the air 76 in the vessel 70 is
atmospheric. Since the liquid 73 in the vessel 70 is at a level
above the vent 71 and the entrance 72, the liquid pressures at
those two locations are greater than atmospheric and liquid flows
from the container 70 through the vent 71 and the entrance 72 into
the holding volume 74 as illustrated in FIG. 7b.
[0061] The liquid 73 continues to flow through the vent 71 until
the pressure of the air 76 in the vessel 70 decreases from
atmospheric by an amount equal to the product of the height of the
liquid surface H.sub.2 above the vent 71 and the liquid density. At
this time, the pressure of the liquid at the vent 71 is equal to
atmospheric pressure and the liquid stops flowing through vent 71
as illustrated in FIG. 7c. The pressure of the liquid 73 at the
entrance 72 is greater than the pressure at the vent 71 by an
amount equal to the density of the liquid times the vertical
distance between the vent 71 and the entrance 72. As illustrated in
FIG. 7c, liquid 73 continues to flow through entrance 72 since it
is below the level of the vent 71.
[0062] Simultaneously with the liquid flow through entrance 72, air
from the holding volume 74 enters the vessel 70 through the vent
71. This flow of air results because the pressure in the vessel 70
tends to decrease as liquid flows out of the vessel 70 through the
entrance 72. As long as the vessel 70 is sealed, except for the
flow through the vent 71 and the entrance 72, the pressure in the
vessel 70 remains constant during this period. Liquid continues to
flow through the entrance 72 (since it is farther from the liquid
level in the vessel than the vent 71) until the level of the liquid
in the holding volume 74 reaches the vent 71. At this time, the
liquid pressure in the holding volume 74 at the vent 71 location is
equal to atmospheric and both the air and liquid flow stop. As
illustrated in FIG. 7d, the holding volume 74 is full of liquid at
the level of the vent 71. This is the measured volume to be
dispensed.
[0063] The operation is summarized as follows. A holding volume 74
is immersed in the liquid in a closed container at atmospheric
pressure. The liquid from the vessel 70 flows into the holding
volume 74 through the vent 71 and entrance 72 due to pressure
differences. As the liquid leaves the vessel 70 and enters the
holding volume 74, the pressure in the vessel 70 decreases until
the liquid pressure in the vessel 70 located at the vent 71 is
equal to atmospheric pressure. The liquid flow through the vent 71
stops because of equal pressures and the flow continues through the
entrance 72 due to pressure differences. The pressure in the vessel
70 tends to decrease due to the flow through the entrance 72 and
causes air from the atmosphere to flow through the opening 75 to
the holding volume 74 and through the vent 72 into the vessel 70 to
maintain the pressure therein constant during this period. The flow
of liquid through the entrance 72 into the holding volume 74
continues until the liquid level in the holding volume 74 reaches
the vent 71. At this time both the airflow and the liquid flow stop
because of equal pressure and a measured volume of liquid is
available for discharge in the holding volume 74.
[0064] When the vessel 70 is inverted, liquid in the holding volume
74 is discharged through the opening 75, and the holding volume 74
is replaced with atmospheric air. When the vessel 70 is reoriented,
the cycle then repeats.
[0065] FIGS. 8a-8d illustrates a liquid dispenser 180 including a
regulator device 181 within a container 182. The regulator device
181 includes a tube 183 having an open end outside of the container
182 and a partially closed end proximate to the bottom of the
container 182. The open end of the tube 183 communicates with the
atmosphere and functions as both liquid discharge orifice and the
air inlet orifice. When the container 182 is orientated upright,
the regulator device 181 is covered with liquid. The tube 183 has a
cavity 186, an entrance 185 located near the bottom of the
container 182, and a vent orifice 184 displaced from the bottom of
the regulator device 181. A measured volume is determined by the
amount that the vent orifice 184 is displaced from the entrance
185.
[0066] When the container 182 is oriented upright, as illustrated
in FIG. 8a, liquid flows from the container 182 through the vent
orifice 184 and entrance 185 into the cavity 186 as a result of the
pressure differences. As liquid flows into the tube cavity 186, the
pressure in the closed container 182 is reduced until the pressure
of the liquid in the container 182 at the vent 184 is equal to the
atmospheric pressure (as illustrated in FIG. 8b). At that time, the
flow of liquid through the vent orifice 184 stops because of the
equal pressures of the liquid in the container 182 at the vent
orifice 184 and the atmosphere (FIG. 8b). However, the pressure of
the liquid at the entrance 185 is greater than atmospheric because
of the added head of liquid. As liquid continues to flow through
the entrance 185 into the tube cavity 186, the pressure in the
container 182 continues to be reduced, causing atmospheric air in
the tube 183 to flow into the tube cavity 186 and then through the
vent orifice 184 into the container 182 to maintain the liquid
pressure at the vent orifice 184 constant at a value of the
atmospheric pressure. When the liquid in the tube cavity 186
reaches the vent orifice 184 there is no longer any driving
pressure force so both the liquid and the airflow stop (FIG. 8c).
This provides the measured volume of liquid for discharge.
[0067] When the container is inverted, as illustrated in FIG. 8d,
the measured volume of liquid from the tube cavity 186 is
discharged through the tube 183. The diameter of the tube 183 is
large enough to allow atmospheric air to bubble into it during
discharge of the liquid. The cycle repeats when the container 182
is oriented upright and atmospheric air enters the cavity 186 and
container through the tube 183.
[0068] FIG. 9 illustrates a variation of the liquid dispenser 180
of FIG. 8. The liquid dispenser 280 of FIG. 9 has a tube 297 with a
constant cross-section. An open end of the tube 297 functions as
both fluid outlet and ambient inlet. A partially closed end of the
tube 297 contains a fluid inlet 285. A measured volume of fluid is
trapped between the fluid inlet 285 and an air transfer orifice
284. The tubes 183 and 297 of the liquid dispensers 180 and 280
could have a circular cross-section or some other
cross-section.
[0069] Reference is now made to FIGS. 10a-10b, which illustrate a
liquid dispenser 380 including a container 342 having a cavity 339,
a closure 345 for the container 342, and a regulator device 341
secured to the closure 345. The regulator device 341 includes a
tube 343 having a first open end 387 outside the container 342 and
a second open end 385 inside the container 342. The first open end
387 of the tube 343 functions as both ambient inlet and fluid
outlet, and the second open end 385 functions as a fluid inlet. The
tube 343 contains an air transfer orifice 384. The fluid inlet 387
and the air transfer orifice 384 define a first trap portion 386. A
curved portion of the tube 343 between the air transfer orifice 384
and the first open end 387 defines a second trap portion 388.
[0070] The device 341 captures a volume in the first trap portion
386 between the air transfer orifice 384 and the fluid inlet 385
orifice. The first time that the liquid dispenser 380 is inverted,
liquid flows from the container cavity 339 through the air transfer
orifice 384 and entrance 385 into the first trap portion 386. When
the liquid dispenser 380 is reoriented in an upright position, the
trapped liquid is transferred to the second trap portion 388. The
regulator device 341 is now primed. When the liquid dispenser 380
is inverted after the first time, the liquid from the first
inversion that was in the second trap portion 386 is discharged at
the open end 387 of the tube 343, as the new volume of fluid enters
the cavity up to the air transfer orifice 384. Once the regulator
device 341 has been primed, a measured volume of fluid can be
discharged each time the liquid dispenser 380 is inverted.
* * * * *