Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02243433 2001-04-17
Title: FLOW VALVE
FIELD OF THE INVENTION
This invention relates to a fluid flow control valve. In
particular, this invention relates to a combined mixing valve and stop
valve which may be used in association with, for example, a hot water
heater.
BACKGROUND TO THE INVENTION
Hot water tanks are used in many applications in both
residential and industrial/commercial applications. Typically, water is
heated in a tank (the hot water tank) and stored there until it is required
for use. Accordingly, the hot water tank has a cold water inlet port so as
to allow water, typically cold water, to be fed into the tank to be heated.
When hot water is required, it is withdrawn through a hot water exit
port.
Typically, a tank for heating hot water has a temperature
control so that the user may adjust the temperature which the water will
reach at steady state. In some applications, it may be advantageous to be
able to moderate the temperature of the hot water without resetting the
temperature of the thermostat of the hot water tank. To do this, cold
water, such as that which is fed to the tank, may be mixed with the hot
water exiting from the tank to obtain a source of water at a moderated
temperature between the temperature of the heated water in the tank
and the temperature of the inlet water to the tank. For example, United
States Patent No. 3,011,523 (Bayer) discloses a mixing valve capable of
mixing hot and cold water to provide water at a moderated temperature.
Bayer discloses such a structure wherein all of the parts are housed within
a singular tubular housing. One disadvantage with the device of Bayer is
that it comprises a complicated construction which is difficult to
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manufacture and assemble thus increasing the cost of the unit as well as
decreasing the reliability of the unit.
SUMMARY OF THF~PRESENT INVENTION
In accordance with the instant invention, there is provided a
flow valve comprising:
(a) a valve seating housing having a cavity, the cavity having
a cold inlet, a first conduit and a variable temperature outlet;
(b) a valve body having a cold inlet port in flow
communication with the cold inlet of the valve seating housing for cold
water to enter the valve body, a first cold outlet port in flow
communication with the first conduit of the valve seating housing for
cold water to enter the first conduit, and a second cold outlet port in flow
communication with the variable temperature outlet for cold water to
enter the variable temperature outlet;
(c) a second conduit in flow communication with the
variable temperature outlet for hot water to enter the variable
temperature outlet, the valve body movably positioned within the valve
seating housing between a first position in which the cold inlet port and
the second cold outlet port are closed, a second position in which the
second cold outlet port is closed and the cold inlet port is at least
partially
open and a third position in which the cold inlet port and the second cold
outlet port are at least partially open; and,
(d) an actuator drivingly connected to the valve body for
moving the valve body between the first, second and third positions.
In one embodiment, a hot outlet port is positioned at one end
of the second conduit and the valve seating housing and the valve body
define the hot outlet port.
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The cold inlet port and the second cold outlet port may be
positioned opposed to each other. Further, the cold inlet port may be
larger than the second cold outlet port.
In another embodiment, the valve body is rotatably mounted
in the valve housing and the cold inlet port is longer in the direction of
rotation of the valve body than the second cold outlet port.
The first conduit may be positioned within the second
conduit. Preferably, the flow valve is adapted for attachment to a hot
water tank having a cold inlet and a hot outlet with the second conduit
connected to the hot outlet from the hot water tank and the first conduit
connected to the cold inlet to the hot water tank.
In another embodiment, the cavity has a wall in which the
inlets and the outlets are positioned and the cold inlet port and the
second cold outlet port are selectively closed or partially closed by
movement of the valve body relative to the valve seating housing so that
the respective port faces, or at least partially faces, the wall.
One advantage of the instant invention is that it provides a
combined mixing valve and stop valve which comprise a minimum of
moving parts. Further, the device is of a simple construction which
facilitates both the manufacture and the assembly of the device. In
addition, due to the simple construction, the device has a high reliability
even after extended use.
A further advantage of the instant invention is that the
connection of the hot and cold water feed pipes to a hot water tank may be
made at a single location. This facilitates the connection of the valve to
the hot water tank. Further, as all plumbing connections to the tank are
made at one particular location, the installation of the hot water tank is
simplified.
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DESCRIPTION OF THE DRAVNING FIGURES
These and other advantages of the instant invention will be
more fully and completely understood in accordance with the following
description of a preferred embodiment of the invention in which:
Figure 1 is a perspective view of a hot water tank with the
flow valve attached;
Figure 2 is an exploded view of the flow control valve shown
in Figure 1;
Figure 3 is a view of the valve housing with the valve body
positioned therein in the direction of arrow 3 in Figure 2;
Figure 4 is a view of the valve housing with the valve body
positioned therein in the direction of arrow 4 in Figure 2;
Figure 5 is a cross-section along the line 5-5 of Figure 2 of the
flow control valve of Figure 2;
Figure 6 is a cross-section along the line 6-6 of the flow
control valve when set into position shown in Figure 5;
Figure 7 is top plan view in the direction of arrow 7 of the
flow control valve when set into position shown in Figure 5;
Figure 8 is a cross-section along the line 5-5 of Figure 2 of the
flow control valve of Figure 2;
Figure 9 is a cross-section along the line 9-9 of the flow
control valve when set into position shown in Figure 8;
Figure 10 is top plan view in the direction of arrow 10 of the
flow control valve when set into position shown in Figure 8.
Figure 11 is a cross-section along the line 5-5 of Figure 2 of the
flow control valve of Figure 2;
Figure 12 is a cross-section along the line 12-12 of the flow
control valve when set into position shown in Figure 11; and,
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Figure 13 is top plan view in the direction of arrow 13 of the
flow control valve when set into position shown in Figure 11.
DESCRIPTION OF 'REFERRED EMBODIMENT
Referring to Figure 1, a flow control valve 10 according to the
instant invention is shown affixed to the top 12 of hot water tank 14.
Cold water feed pipe 16 is affixed to one port of flow control valve 10 and
hot water pipe 18 is affixed to another port of valve 10. It will be
appreciated by those skilled in the art that flow valve 10 may be connected
to tank 14 at any desire location and need not necessarily be connected to
tank 14 at top 12.
The hot water tank may be of any type which is used either
residentially or commercially/industrially. Hot water tank 14 may be any
tank known in the art which is used to heat water or heat water and store
the heated water for later use. Generally, hot water tank 14 includes a
vessel for receiving water and one or more heating devices for heating
the water in the vessel (not shown). The heating device may use
combustion (e.g. the combustion of oil or natural gas). Alternately, the
heating device may comprise electrical resistance heating.
Referring to Figure 2, it can be seen that flow valve 10
comprises valve housing 20, valve body 22 and control knob 24.
Valve housing 20 is provided a plurality of conduits for
receiving and delivering cold water to tank 14 and for receiving hot water
from tank 14 and delivering it to an external member such as hot water
pipe 18. As shown in Figures 2 and 5, valve housing 20 has a first conduit
30, a second conduit 32 and a third conduit 34. The distal ends 36, 38 and
40 of conduits 30, 32 and 34 may be adapted, such as by providing a
threaded screw, to assist the connection of flow valve 10 to hot water tank
14 and the plumbing where the tank is installed. The threaded screw may
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be provided on the external surfaces of conduits 30, 32 and 34, or
alternately, as shown in Figure 5, they may be provided on the internal
surface. Valve housing 20 also has an inner wall 42, the inner surface of
which defines a cavity within which valve body 22 is received (see Figure
5). Inner wall 42 is provided with a first opening 44, a second opening 46
and a third opening 48 (see Figure 5).
As shown in the drawings, valve housing 22 is preferably
general T-shaped with first and third conduits 30, 34 extending in a
straight line and conduit 32 extending downwardly therefrom at about a
ninety degree angle. It will be appreciated that first and third conduits 30,
34 need not be set in an opposed fashion but may define any angle
between the conduits provided that the valve body is modified so that it
may be adjusted between one position in which it is sealed with respect to
at least one of the conduits and another position in which it is in full
communication with both conduits.
Valve body 22 has an inner surface 50, an outer surface 52,
first port 54, second port 56 and third port 58. Valve body 22 may be of any
particular shape provided it is sized to fit within the cavity of valve
housing 20 and is movably mounted therein so as to selectively open first
port 54 and third port 58. Preferably inner wall 42 of the cavity in valve
housing 20 in which valve body 22 is received is cylindrical and outer
surface 52 of valve housing 50 is also cylindrical but slightly smaller.
Accordingly, valve body 22 may rotate within valve housing 20. The
distance between inner wall 42 of the cavity of valve housing 20 and
outer surface 52 of valve body 22 is sufficiently large such that valve body
22 may freely rotate by pressure applied through control knob 24 and
sufficiently small so that water, or any other fluid that may be passing
therethrough, will not seep therebetween.
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First port 54 and third port 58 are positioned so that when
valve body 22 is positioned in the cavity of valve housing 20, first port 54
may be aligned with first conduit 30 and third port 58 may be aligned with
third conduit 34. As shown in the preferred embodiment, first and third
ports 54 and 58 are positioned in an opposed fashion in a similar manner
to first and third conduits 30 and 34. It will be appreciated that if first
and
third conduits 30 and 34 are at an angle to each other, that first and third
ports 54 and 58 would have to be comparably moved. Second port 56 is
positioned so as to be aligned with second conduit 32.
Valve housing 20 may also be provided with a plate 60
having an upper surface 62. As shown in Figures 7, 10 and 13, upper
surface 62 may be provided with a label indicating the various positions
to which control knob 24 may be positioned. Plate 60 may be mounted on
valve 10 by, for example, providing a circular cut-out section in the centre
thereof and then placing plate 60 on top of valve housing 20 as shown in
Figure 5.
Control knob 24 may be drivingly connected to valve body 22
by any means known in the art. As shown in Figure 2, valve housing 20
may have an upwardly extending upper mounting member 64 having a
threaded surface 66 provided on the distal end thereof. A mounting cap
68 having a threaded surface 70 may be provided. Threaded surfaces 66
and 70 are sized so that mounting cap may be screwed onto upper
mounting member 64 as shown in Figure 5.
Valve body 22 has an upwardly extended member 72 which
extends upwardly through opening 74 of mounting cap 68 and is adapted
to be secured to control knob 24 so that rotation of control knob 24 will
cause valve body 22 to rotate. Control knob 24 may be affixed to upper
section 76 by any means known in the art such as, for example, a set screw
(not shown). Preferably, at least upper section 76 of upwardly extending
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member 72 has a square cross-sectional profile which is matingly engaged
in a similarly sized recess of control knob 24 (not shown). In order to
provide a bearing surface between valve body 22 and mounting cap 68, O-
ring 78 may be provided. O-ring 78 may be made, for example, from a
self-lubricating plastic member, such as nylon, so as to reduce frictional
forces which would otherwise arise from the rotation of valve body 22
within valve housing 20 relative to mounting cap 68.
Valve body 22 is connected to a fourth conduit 80 so as to
direct the incoming fluid through second port 56 without the fluid
mixing with the fluid exiting valve 10 via third conduit 34. Accordingly,
as shown in Figure 5, fourth conduit 80 is secured to valve body 22
adjacent second port 56. For example, fourth conduit 80 may have a distal
end which has a threaded surface 82 applied thereon. Threaded surface 82
is sized so as to be threadedly received in the threaded surface of second
port 56. Fourth conduit 80 may be the feed pipe which extends outwardly
from tank 14. Alternately, fourth conduit 80 may be adapted to be
connected to the feed pipe to tank 14 as its known in the art. Similarly,
second conduit 32 may be adapted to be connected to the exit pipe from
tank 14 by any means known in the art. As shown in Figure 2, the distal
end of second conduit 32 has a threaded surface 84 which may threadedly
engage the exit pipe from tank 14.
Valve 10 further comprises a passageway 86 so as to allow the
heated water exiting tank 14 to travel to third conduit 34. Preferably,
passageway 86 is defined by valve housing 20 and valve body 22.
Referring to Figures 2 and 5, the lower pardon of valve body 22 has an
undercut portion. In particular, valve body 22 is provided with a lower
section 92 which is of a reduced diameter compared to outer surface 52.
Lower surface 90 extends between outer surface 52 of valve body 22 and
the outer surface of lower section 92. Thus, in the preferred embodiment,
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passageway 86 is defined between lower section 92 and inner wall 42.
Accordingly, passageway 86 and third opening 48 permit the water
exiting tank 14 to be in flow communication with third conduit 34.
In the preferred embodiment, first port 54 is larger than
third port 58 so as to force some of the water entering first conduit 30 to
pass downwardly through second conduit 32 into tank 14 where it may
be heated. Further, first port 54 is also preferably larger than third port
58 so that third port 58 may be partially and, preferably, fully closed
while first port 54 is still open and, preferably, substantially open. Thus,
as shown in Figure 6, first port 54 may describe a larger arc in the radial
direction R than third port 58.
The operation of valve 10 will now be described with
reference to Figures 5 -7, 8 - 10 and 11 - 13 which show preferred
positions of valve 10. In the position shown in Figures 5 - 7, port 54 is
fully aligned with first opening 44. Further, third port 58 is fully aligned
with second opening 46. In this position, the supply of cold water to tank
14 is in the fully opened position. Further, third port 58 is also fully
aligned with second opening 46 thus maximizing the amount of water
entering first conduit 30 which may pass through third port 58 and
second opening 46 into third conduit 34. If first conduit 30 is connected to
a source of cold water, then cold water will enter first conduit 30 and pass
through first opening 44 and first port 54 into valve body 22. A portion
of the water will pass downwardly through second port 56 into fourth
conduit 80 where is may enter tank 14 and be heated and stored until
needed. A portion of the water will pass through third port 58 and
second opening 46 into third conduit 34. Water, which may have been
heated in tank 14, exits through passageway 86, through third opening 48
into third conduit 34. Presuming tank 14 has been actuated to heat the
water, and the water has been in tank 14 for awhile, hot water will exit
third opening 48 and
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rnix with cold water exiting second opening 46. On mixing, the
temperature of the hot water exiting third opening 48 will decrease. Since
third port 58 is fully on, this will result in the minimum temperature for
the water in third conduit 34.
By rotating control knob 24, valve body 22 may be rotated
within valve housing 24 so that third part 58 may be partially closed, and
preferably, fully closed (as shown in Figure 9). As will be appreciated
from Figure 9, as first port 54 describes a greater arc, it may remain
substantially in the fully on position while third port 58 is in the fully
closed position. In the position shown in Figure 9, cold water may enter
through first opening 44 and first port 54 into valve body 22. Third port
58 opens onto inner wall 42 of valve housing 20. Accordingly, all of the
incoming cold water will pass downwardly through fourth conduit 80
into tank 14 where it may be heated. Third opening 48 is still open.
Accordingly, hot water may exit through passageway 86 and third
opening 48 into third conduit 34. As no cold water exits third port 58 to
mix with the hot water, this position represents the maximum hot water
temperature which may be achieved using valve 10.
If it is necessary to service the unit, or for other reasons, the
supply of cold water to tank 14 may be discontinued by moving control
knob 24 to the position shown in Figure 13. In this position, both third
port 58 and first port 54 open onto inner wall 42 of housing 20.
Accordingly, the water in conduit 30 will pass through first opening 44
where it will contact valve body 22. Thus, no cold water will pass
through fourth conduit 80 into tank 14. It will be appreciated that by
rotating handle 24 slightly, first port 54 may be gradually opened so as to
allow a diminished flow of water, as may be desired, into tank 14.
It will be appreciated by those skilled in the art that various
modifications may be made to valve 10 and that all of these modifications
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are within the scope of this invention. In particular, it will be appreciated
that each port 54 and 58 may comprise a plurality of ports as opposed to
a single port describing a wide arc. Similarly, first opening 44 and second
opening 46 may each describe a series of openings. The relative size of
first port 54 compared to third port 58 may be varied depending upon
the amount of cold water which is desired to pass directly through valve
without entering tank 14.
