Water dispenser abstract
An anti run-on device is provided for use in a refrigeration appliance,
wherein the refrigeration appliance includes a water dispenser including
a water reservoir, a water conduit extending downstream from the
water reservoir to a water spout, and a user operable valve positioned
in the water conduit upstream of the reservoir and the water spout.
The anti run-on device comprises a constriction in the conduit between
the valve and the water spout, a small hole in the conduit located
either at or just downstream of the constriction, and a vacuum chamber
in communication with the small hole. A Venturi or knife edge effect
is created when water is flowing through the conduit to evacuate
the vacuum chamber, so that when the valve is closed, water between
the small hole and the water spout is drawn into the vacuum chamber,
thereby precluding dripping from the water spout.
Water dispenser claims
The embodiments of the invention in which an exclusive property
or privilege is claimed are defined as follows:
1. An anti run-on device for use in a refrigeration appliance,
wherein said refrigeration appliance includes a water dispenser
including a water reservoir, a water conduit extending downstream
from said water reservoir to a water spout, and a user operable
valve positioned along said water conduit upstream of said reservoir
and said water spout, said anti run-on device comprising: a constriction
in said conduit between said valve and said water spout; a small
hole in said conduit located one of at and just downstream of said
constriction; and a vacuum chamber in communication with said small
hole.
2. An anti run-on device according to claim 1 wherein said constriction
is formed by a restrictor member inserted into said conduit.
3. An anti run-on device according to claim 2 wherein said restrictor
member includes a passage therethrough with a diameter smaller than
an interior diameter of said conduit.
4. An anti run-on device according to claim 3 wherein said passage
is provided with a cone shaped lead in.
5. An anti run-on device according to claim 3 wherein said passage
comprises an opening in a disk-shaped insert.
6. An anti run-on device according to claim 1 wherein said vacuum
chamber is formed by vacuum chamber walls which are rigid.
7. An anti run-on device according to claim 1 wherein said vacuum
chamber is formed by vacuum chamber walls which are flexible and
resilient.
8. An anti run-on device according to claim 1 wherein said vacuum
chamber surrounds said conduit.
9. An anti run-on device according to claim 1 further including
a water chamber provided upstream of said small hole.
10. A refrigeration appliance comprising: a water reservoir; a
water conduit extending downstream from said reservoir to a water
spout and upstream of said reservoir; a control valve positioned
along said water conduit; an anti run-on device positioned in said
conduit downstream of said control valve, said anti run-on device
comprising: a constriction in said conduit; a small hole in said
conduit located one of at and just downstream from said constriction;
and a vacuum chamber in communication with said small hole.
11. A refrigeration appliance according to claim 10 wherein said
constriction is formed by a restrictor member inserted into said
conduit.
12. A refrigeration appliance according to claim 11 wherein said
restrictor member includes a passage therethrough with a diameter
smaller than an interior diameter of said conduit.
13. A refrigeration appliance according to claim 12 wherein said
passage comprises an opening in a disk-shaped insert.
14. A refrigeration appliance according to claim 12 wherein said
passage is provided with a cone shaped lead in.
15. A refrigeration appliance according to claim 10 wherein said
vacuum chamber is formed by vacuum chamber walls which are rigid.
16. A refrigeration appliance according to claim 10 wherein said
vacuum chamber is formed by vacuum chamber walls which are flexible
and resilient.
17. A refrigeration appliance according to claim 10 wherein said
vacuum chamber surrounds said conduit.
18. A refrigeration appliance according to claim 10 further including
a water chamber provided upstream of said small hole.
19. An anti run-on device for use in a liquid conduit and positioned
between a shut off valve and an open end of said conduit, comprising:
a constriction in said conduit between said valve and said water
spout; a small hole in said conduit located one of at and just downstream
of said constriction; and a vacuum chamber in communication with
said small hole.
20. An anti run-on device according to claim 19 wherein said vacuum
chamber is formed by vacuum chamber walls which are rigid.
21. An anti run-on device according to claim 19 wherein said vacuum
chamber is formed by vacuum chamber walls which are flexible and
resilient.
22. An anti run-on device according to claim 19 further including
a water chamber provided upstream of said small hole.
Water dispenser description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to water dispensers, and more
particularly, to a water dispenser for use with a refrigeration
apparatus and including an arrangement to prevent dripping or run-on
of the water dispenser.
[0002] Manufacturers of refrigerators have offered, as a feature
of their product, a water dispenser mounted to the exterior of the
refrigerator door. Such a water dispenser is usually combined with
a water reservoir, remotely located within the refrigerated compartment,
to provide ready access to chilled water without the need to open
the refrigerator door. A conduit extends between the water reservoir
and the water spout from which the water is directed into a vessel
such as a drinking glass. A valve, typically operated by a lever
arm pressed by a glass is used to control the dispensing of water.
[0003] A common problem, associated with refrigerator dispenser
mechanisms, is run-on. Run-on is dripping of water from the tube
while it is not in use. There are several causes of run-on. The
water reservoir expands when pressurized and contracts when de-pressurized.
This causes water to run for a short time immediately after removing
the glass. This effect is enhanced by compressible air bubbles trapped
in the water reservoir. Dissolved air in the water can come out
of solution at the low pressures in the reservoir. The added volume
causes run-on. Water reservoirs sometimes freeze. The expanding
ice displaces water causing dripping. All of these effects are caused
by a volumetric displacement of water somewhere in the dispensing
system after the water valve is turned off.
SUMMARY OF THE INVENTION
[0004] The present invention provides an arrangement for preventing
dripping from the water spout in a water dispenser for a refrigerator
after the shut off valve has been closed. Immediately upon the shut
off valve being closed, any water in the conduit from the point
of the shut off valve to the water dispenser is withdrawn back into
the conduit by a suction force, thereby preventing any dripping
from the water spout. In an embodiment, a reservoir is provided
which communicates with the conduit and which is maintained below
atmospheric pressure during a flow of water through the conduit
such that when the valve is closed, any water remaining in the conduit
from the valve to the water spout is drawn into the reservoir area
by a suction action and is held there until a further dispensing
of water occurs.
[0005] In an embodiment, the invention comprises the use of a rigid
plastic tube which is surrounded by a vacuum chamber. A Venturi
type vacuum device is built into the plastic tube so that when water
passes through it, a vacuum is created in the surrounding chamber.
When the water is turned off, water flows into the vacuum chamber
due to the reduced pressure. This creates a volumetric buffer for
any type of run-on that may occur. The vacuum chamber may be made
of a rigid material if a small buffer is desired or an elastic material
for a larger buffer volume. In the rigid design, a pressure lower
than the vapor pressure of water is required to create the buffer.
In the elastic design, the vacuum chamber material could have some
degree of shape memory. When the water is flowing, the elastic vacuum
chamber collapses due to the reduced pressure inside. When the water
is turned off, it would expand, creating a larger buffer volume.
There should be sufficient internal volume in the dispensing conduit,
in the direction of flow, downstream of the vacuum chamber, to prevent
external air from entering the vacuum chamber.
BRIEF DESCRIPTION OF THE DRAWING
[0006] FIG. 1 is a front view of a refrigerator having a water
dispenser incorporating the principles of the present invention.
[0007] FIG. 2 is a side view of a water dispenser with which the
present invention can be utilized, taken generally along the line
II-II of FIG. 1.
[0008] FIG. 3 is the same view as FIG. 2 but showing the water
dispenser actuated by a drinking glass.
[0009] FIG. 4 is a schematic illustration of an arrangement for
locating the anti-run-on device of the present invention in a water
flow line.
[0010] FIG. 5 is a side sectional view of an embodiment of the
present invention.
[0011] FIG. 6 is a side sectional view of an embodiment of the
invention.
[0012] FIG. 7 is a sectional view taken generally along the line
V-V of FIG. 4.
[0013] FIG. 8 is a side sectional view of a further embodiment
of the present invention.
[0014] FIG. 9 is a side elevation view of an embodiment of the
present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0015] The present invention relates to an anti run-on device for
preventing dripping from a conduit after a liquid valve has been
closed. While the invention finds particular utility in a refrigeration
appliance where a water dispenser may be provided in the door of
the appliance, the invention is not limited to such use and can
be used in any liquid conduit positioned between a shut off valve
and an open end of the conduit. However, to provide a specific example
of the invention, the invention is disclosed as used in connection
with a refrigeration appliance.
[0016] Referring to FIG. 1 a refrigerator 20 is provided with
a door 22 for gaining access to a below freezing compartment (not
shown). Located centrally on the outer face of the door 22 is an
outwardly opening housing 24 in which are mounted an ice dispenser
26 and a water dispenser 28.
[0017] As shown in FIG. 2 the water dispenser 28 has an actuator
30 which is pivotally attached to a back surface 32 of housing 24
by a pin 34. An upper extension 36 of dispenser actuator 30 terminates
in a pad 38. A dispensing switch 40 is mounted with a push button
type operator 42 in alignment with the pad 38 so that when the dispenser
actuator 30 is rotated counter clockwise around the pin 34 the
pad 38 will actuate the operator 42 as seen in FIG. 3. A torsion
spring (not shown) associated with the pin 34 biases the actuator
30 to the position shown in FIG. 2. Thus, after the actuator 30
is rotated to the position shown in FIG. 3 it will subsequently
return to the position shown in FIG. 2.
[0018] Operation of the switch 40 completes an electrical circuit
between a source of power and a solenoid operated valve 44 (FIG.
4) connected to a water supply. The solenoid valve 44 is also connected
to a water reservoir 46 which is connected to a water spout 48 by
an interconnecting tube or conduit 50. Thus, when the valve 44 is
opened, pressurizing reservoir 46 water is caused to be delivered
to the water spout 48.
[0019] A lower extension 52 of the actuator 30 terminates in a
cradle shaped glass receiving portion 54. As illustrated in FIG.
3 the glass receiving portion 54 is configured to allow a drinking
glass to be conveniently pressed against the dispenser actuator
30 and dispense water from the water spout 48 located above the
glass receiving portion 54 into the glass.
[0020] In FIG. 4 there is schematically illustrated an improved
water dispensing system incorporating the principles of the present
invention. The water spout 48 is shown as being connected by the
tube or conduit 50 to the water reservoir 46 and dispensing valve
44 and also including the improvement of the provision of anti
run-on device 60 being positioned in the conduit 50 between the
water reservoir 46 and the water spout 48.
[0021] In FIG. 5 there is illustrated an embodiment of the anti
run-on device 60 incorporating the principles of the present invention.
In this embodiment, the conduit 50 is severed and a rigid tube 62
is slipped over the severed ends of the conduit 50 and is secured
thereto by appropriate fastening means such as compression nuts
64. The rigid tube 62 may be formed of any acceptable material,
including appropriate plastic materials. A restrictor 66 is inserted
into the rigid plastic tubing adjacent to an end of the conduit
50 which leads downwardly (in FIG. 5) to the water reservoir 46.
The restrictor 66 has a reduced diameter passage 68 therethrough
and may include a funnel shaped lead in opening 70 to guide the
water into the passage 68. Immediately downstream of the end of
the reduced diameter passage 68 the rigid tube 62 has a relatively
small hole 72 formed therein. A vacuum chamber 74 formed by a vacuum
chamber wall 76 surrounds the rigid plastic tube 62 and including
the area including the hole 72.
[0022] As water flows from the water reservoir 46 to the water
spout 48 it flows in an upward direction, in the orientation of
FIG. 5 through the conduit 50 and passes through the reduced diameter
passage 68. Because of the reduced diameter of the passage 68 the
speed of the water flow increases and therefore the pressure decreases.
This produces a reduced pressure zone in the area at the hole 72
(a Venturi effect) and thereby reduces the pressure in the vacuum
chamber 74 causing any liquid in that chamber to be drawn out of
the chamber and intermingled with the water stream proceeding to
the water spout 48. If the vacuum chamber wall 76 is formed of a
rigid materials, then preferably the passage 68 of the restrictor
66 is sized, in combination with the flow rate through the conduit,
to reduce the pressure in the vacuum chamber 74 below the vapor
pressure of water, so as to cause all of the water collected in
the vacuum chamber 74 to be drawn through the hole 72 and into the
conduit 50 as water is dispensed through the water spout 48. If
the vacuum chamber wall 76 is formed of a flexible material, then
the pressure in the vacuum chamber 74 only needs to be reduced to
below atmospheric pressure, which will result in a collapsing of
the wall 76 and a subsequent squeezing of the water out of the vacuum
chamber.
[0023] When the dispensing of water is terminated by release of
the actuator 30 water downstream of the restrictor 66 that is,
between the restrictor and the water spout 48 is drawn by the reduced
pressure in the vacuum chamber 74 through the hole 72 and into the
vacuum chamber, thereby withdrawing an end of the remaining water
column in the conduit 50 away from the water spout 48 and toward
the anti run-on device 60. The size of the vacuum chamber 74 is
selected so that it will accommodate a sufficient volume of water
at the conclusion of each dispensing operation to withdraw the end
of the water column in the conduit 50 far enough away from the water
spout 48 such that any expansion or volumetric displacement of the
water in the dispensing system after the water valve has been turned
off will be insufficient to cause the end of the water column in
the conduit from moving all of the way to the water spout 48. The
size of the vacuum chamber 74 should also be selected so as to draw
thereinto less than all of the water between the vacuum chamber
and the water spout 48 so that air is not drawn into the vacuum
chamber from the water spout opening.
[0024] A second embodiment of the anti run-on device 60 is illustrated
in FIGS. 6 and 7 in which a metal insert tube 80 is placed into
the interior of the conduit 50. The insert tube 80 may be formed
of metal, such as brass, or an appropriate plastic. A restrictor
82 is provided in the insert tube 80 and includes a reduced diameter
opening 84 through which the water flows from the water reservoir
46 to the water spout 48 (from left to right in FIG. 6). The restrictor
82 may be an opening 84 in a disk-shaped insert, such as a flat
washer, and the opening 84 creates a "knife edge" effect,
reducing the pressure in the area just downstream of the restrictor.
A sloped or conical lead in zone is not necessary when using a knife
edge restrictor, and such a construction can be used in any of the
embodiments of the anti run-on device disclosed herein. The insert
tube 80 as well as the conduit 50 are provided with a hole 86
just downstream of the restrictor 82. Surrounding the insert tube
80 and conduit 50 in the area including the hole 86 is a vacuum
chamber 88 formed by a vacuum chamber wall 90 (rigid or flexible
as described above). The vacuum chamber wall includes a central
portion 92 spaced away from the conduit 50 and end portions 94 spaced
closely adjacent to the conduit 50 such that a water tight seal
can be effected between the end portions 94 and the conduit 50 by
appropriate means. If the conduit 50 and the vacuum chamber wall
90 are both formed of appropriate plastic materials, the end portions
94 can be sealed to the conduit 50 such as by hot staking. As in
the previous embodiment, when water flows from the water reservoir
46 to the water spout 48 it passes through the opening 84 of the
restrictor 82 thereby reducing pressure adjacent to the hole 86
and creating a low pressure area within the vacuum chamber 88 withdrawing
any collected water therefrom into the conduit 50 for dispensing
through the water spout 48. When the actuator 30 is released, thereby
terminating water flow through the conduit 50 the end of the water
column in the conduit 50 is drawn back toward the anti run-on device
60 in that a volume of water is drawn into the vacuum chamber 88
due to the low pressure residing therein. The same volume considerations
described in the previous embodiment pertain to this embodiment
as well. Hence, the volume of the vacuum chamber 88 will be determined,
in part, by the distance from the anti run-on device 60 to the water
spout 48 and the diameter of the conduit 50.
[0025] In FIGS. 8 and 9 there is shown another embodiment of the
anti run-on device 60. In this embodiment, the device is preferably
formed as a one piece, blow molded, construction and can be made
of a plastic material such as medium density polyethylene.
[0026] As seen in FIGS. 8 and 9 the anti run-on device 60 includes
an inlet tube 100 for connection to the conduit 50 leading to the
water reservoir 46. There is also an outlet tube 102 for connection
to the conduit 50 leading to the water spout 48 or, the outlet
tube 102 may comprise the water spout 48 itself. An internal diameter
104 of the inlet tube 100 is reduced to a much smaller internal
diameter at a passage 106 downstream of the inlet tube 100 and the
reduction in diameter can be provided by a cone shaped wall 108.
Alternatively, a knife edge restrictor could be used as described
above to provide the constriction in the inlet tube 100. In the
reduced diameter passage 106 there is a hole 110 leading to a vacuum
chamber 112 formed by vacuum chamber wall 114 (rigid or flexible
as described above).
[0027] Positioned between the outlet tube 102 and the reduced diameter
passage 106 is a water chamber 116 through which the water flows
from the water reservoir 46 to the water spout 48 which is particularly
useful when the outlet tube 102 is the water spout 48.
[0028] As in the embodiments above, when water is being dispensed,
the speed of the water flow is greatly increased in the reduced
diameter passage 106 thereby creating a low pressure in the area
of the hole 110 and reducing the pressure within the vacuum chamber
112 so that all of the water contained therein is withdrawn through
the hole 110 and dispensed along with the water flow which then
passes through the water chamber 116 and the outlet tube 102 to
the water spout 48. When the actuator 30 is disengaged and water
through the conduit stops flowing, the water between the hole 110
leading to the vacuum chamber 112 and the water spout 48 is sucked
into the vacuum chamber 112 through the hole 110 and the end of
the water column is drawn away from the water spout 48. The water
chamber 116 is provided in the event that the anti run-on device
60 is placed very close to the water spout 48 such as when the
outlet tube 102 is the water spout. As described above, it is not
desired to draw air into the vacuum chamber 112 and therefore a
sufficient volume of water must be present between the vacuum chamber
hole 110 and the end of the water column near the water spout 48
when flow is terminated so that the entire water column is not drawn
into the vacuum chamber 112 thereby allowing air to also come into
the vacuum chamber. Therefore, the water chamber 116 is dimensioned
to provide a sufficient volume of water to be drawn into the vacuum
chamber 112 after the flow of water is terminated so as to prevent
any air from being drawn into the vacuum chamber 112. Upon the next
dispensing of water, any water still remaining in the water chamber
116 as well as water drawn into the vacuum chamber 112 will be
dispensed out through the outlet tube 102 and to the water spout
48.
[0029] As is apparent from the foregoing specification, the invention
is susceptible of being embodied with various alterations and modifications
which may differ particularly from those that have been described
in the preceding specification and description. It should be understood
that the scope of the patent warranted hereon is intended to include
all such modifications as reasonably and properly come within the
scope of the disclosed contribution to the art. |