Note: Descriptions are shown in the official language in which they were submitted.
TITLE: WALL WATER HYDRANT HAVING BACKFLOW AND
BACK SIPHONAGE PREVENTOR
BACKGROUND OF THE INVENTION
This invention relates to the protection of water
hydrants from undesirable backpressure backflow, and back
siphonage backflow. Hoses and equipment are frequently
connected to freezeless outdoor water hydrants to accomplish
various tasks. Significant backpressure or siphonage can be
encountered during some tasks, particularly if a break occurs
in the primary water line.
Freezeless wall faucets or hydrants are known in the
art. Generally, these devices include a hollow housing
having an interior inlet and connected to a source of
pressurized water and an exterior outlet. A valve is
included within the housing and is connected by means of a
rod to a manually operable handle outside the housing.
Rotation of the handle causes the valve to open and close.
Freezeless faucets are normally wall-mounted on the exterior
of a building with the valve extending inwardly with respect
to the building to a point where the valve is protected from
freezing by warmth from the interior of the building. The
handle and outlet are located on the exterior of the
building.
A freezeless water faucet with a removable valve
cartridge is shown in U.S. Patent 4,821,762~.te~~ Breneman. The
removable valve cartridge is supported on an operating rod
which extends centrally within a bore in the elongated
housing of the faucet. Various methods have been tried in
conjunction with such faucets to control the flow and
backpressure within to prevent damage and contamination.
Unfortunately, face sealing backflow preventors like the one
shown by Breneman adversely affect the output flow
characteristics of the faucet and require a separate spring
and seat for proper sealing. In freezeless faucets, it is
difficult to accommodate backpressure preventors within the
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housing without interfering with the operation of the
centrally located valve cartridge.
Therefore, a principal object of this invention is to
provide an improved backpressure and back siphonage preventor
for a freezeless hydrant.
A further object of the present invention is to provide
a backflow and back siphonage preventor which is mounted to
the operating rod and seals against the wall of the hollow
housing when the fluid forces are greater downstream than
upstream of the preventor.
A further object of the present invention is to provide
a backflow and back siphonage preventor which allows water to
be delivered from the source so long as the valve is open and
the fluid forces are greater upstream than downstream of the
preventor.
A further object of the present invention is to provide
a backflow and back siphonage preventor which is durable,
readily serviceable, inexpensive to manufacture, and capable
of self-flushing for removal of debris during operation.
A further object of this invention is to prevent failure
of the backflow preventor, and particularly the sealing
element forming a part thereof, under conditions of high
fluid pressure.
SUMMARY OF THE INVENTION
The wall mounted water hydrant of this invention has an
elongated hollow housing with water inlet and outlet ends,
and a center axis; a water inlet valve means in the housing
adjacent to the inlet end, including a valve seat and a valve
body; a water outlet port in the housing adjacent to its
outlet end; a valve operating rod in the housing with its
inner end secured to the valve body and an outer end
extending along the center axis to the outlet end of said
housing where a handle is attached thereto for rotating the
operating rod. Rotation of the rod in one direction will
advance the valve body on to the valve seat, and rotation of
the rod in an opposite direction will retract the valve body
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away from the seat, Thus providing a gap therebetween
through which pressurized water connected to the inlet can
flow in a downstream direction through the housing and exit
through the outlet port. A backflow preventor element is
secured to the valve means downstream from the valve seat.
The term backflow preventor as used herein will refer to both
the concepts of back siphonage backflow as well as
backpressure backflow.
The backflow preventor has a cylindrical body element
with a smaller diameter than the interior of the housing and
an outward cylindrical periphery with a flexible flange
normally extending outwardly therefrom to engage the interior
surface of the housing. The flexible flange is constructed
to permit it to deflect toward the axis of the housing when
water is flowing in a downstream direction and to deflect
outwardly from the housing axis to engage the interior
surface of the housing if backpressure or back siphonage
urges water to flow in an upstream direction. Thus the
housing and valve means are selectively sealed against
backflow occurring from all causes. Part or all of the
backflow preventor may be made from elastomeric material for
improved deflection and sealing characteristics. The
backflow preventor has a hollow or bell shape with triangular
shaped flange that can bear against the interior surface of
the housing to create a seal under backflow conditions.
DESCRIPTION OF THE DRAWINGS
Figure 1 is a perspective view of the water hydrant of
the present invention mounted to the outer wall of a house.
Figure 2 is a sectional view taken along line 2-2 of
Figure 1 showing the water hydrant in its closed position.
Figure 3 is an enlarged sectional view of the hydrant in
its open position.
Figure 4 is a view similar to Figure 3, but showing the
valve assembly in its open, but backflow preventing position.
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Figure 5 is a perspective view of the valve assembly
with the backflow preventor of this invention installed
thereon.
Figure 6 is a sectional view taken along line 6-6 of
Figure 4 showing the backflow preventor on the valve
assembly.
Figure 7A is an enlarged section view of the backflow
preventors, in its expanded state, sealing against the
interior of the housing.
Figure 7B is an enlarged section view of the backflow
preventor, in its crimped state, deflecting toward the axis
of the housing to allow inlet water to flow over the
preventor.
Figure 8 is a large scale sectional view through a
modified form of a valve casing.
Figure 8A is a view similar to that of Figure 8 but
shows a backflow preventor mounted thereon.
Figure 9 is a smaller scale cross sectional view through
a modified form of a valve casing.
Figure 9A is a view similar to that of Figure 9 but
shows a backflow preventor mounted thereon.
Figure 10 is a smaller scale cross sectional view
through a modified form of a valve casing.
Figures l0A is a view similar to that of Figure 10 but
shows a backflow preventor mounted thereon.
Figure 11 is a smaller scale cross sectional view
through a modified form of a valve casing.
Figures 11A is a view similar to that of Figure 11 but
shows a backflow preventor mounted thereon.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to Figure 1, the numeral 10 generally
designates the wall-mounted water hydrant of the present
invention. As shown in Figure 2, hydrant 10 includes a
hollow elongated housing 12 having a central elongated bore
14. One end of bore 14 is in sealed engagement with the
middle portion of a hollow brass connector 16. The upper and
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2160940
lower ends 18, 20 of connector 16 have male pipe threads as
showing in Figure 2. The lower end 20 of connector 16 is
threaded into inlet pipe 22, which is connected to a
conventional source of pressurized water. The other end of
bore 14 is connected to a water outlet port 24 and a vacuum
breaker 25, which the particulars of are not crucial to the
present invention.
A movable valve assembly 26, located centrally and
removably within bore 14, is in conventional sealed
engagement with the end of the bore 14 that is associated
with the outlet port 24. Movable valve assembly 26 can be
retracted from a close position shown in Figure 2 to the open
position shown in Figure 3 by a manual means for rotating,
such as a handle 28, which is connected to one end of an
elongated operating rod 30. Referring again to Figure 2, the
other end of operating rod 30 is connected to the upper end
of a valve casing 32.
Valve casing 32 has upper and lower portions 34, 36.
The lower portion 36 is larger in diameter than the upper
portion 34 and there is an intermediate necked portion 35
between the two. As best seen in Figure 5, the lower portion
36 of valve casing 32 is hollow with a plurality of apertures
38 extending through the lower portion 36 and into the necked
portion 35. Apertures 38 allow water to flow from the inlet
through the valve assembly 26 to the outlet port 24 under
conditions shown in Figure 3. Figure 2 shows that lower
portion 36 of valve casing 32 and the upper end 18 of
connector 16 are joined in conventional sealed engagement by
pipe threads. When its threads are fully engaged, the upper
end 18 of connector 16 extends adjacent to, but does not
completely cover the apertures 38 in valve casing 32. As
shown in Figure 4 and Figure 6, the inside of the necked
portion 35 of the valve casing 32 and the upper end of
connector 16 form annular seats 39 around a valve opening 40.
Valve closure element or body 42 is fastened by
conventional means to the end of operating rod 30 opposite
handle 26. Valve body 42 is smaller in diameter than the
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interior of the lower portion 36 of valve casing 32, but
greater in diameter than the interior of the upper end 18 of
connector 16. To assemble movable valve assembly 26,
operating rod 30 is first attached to the upper portion 34 of
valve casing 32. Then valve body 42 is put inside the lower
portion 36 of the valve casing 32 and then fastened to the
end of operating rod 30. The resulting movable valve
assembly 26, shown in Figure 2 and Figure 5, can be retracted
or advanced axially within bore 14 by rotating handle 28.
When handle 28 is rotated in one direction, valve body 42
eventually comes into contact with the end of connector 16 as
shown in Figure 2. In this position, valve body 42 is seated
on seats 39 and the flow of fluid from inlet pipe 22 to the
outlet port 24 is blocked.
Figure 6 shows valve assembly 26 after it has been
rotated in the opposite direction. Valve body 42 has been
withdrawn from seats 39 to create a valve opening 40. Valve
body 42 acts in conjunction with connector 16 to form an
inlet valve means for operating the hydrant. Fluid is
thereby permitted to flow through inlet pipe 22, connector
16, valve opening 40, apertures 38 around operating rod 30
and to outlet port 24.
Figure 4 shows the effects of backpressure on the
hydrants of this invention. To prevent backflow, which can
be caused by excessive water pressure at outlet port 24, a
backflow preventor 44 is installed into groove 45 in the
upper portion 34 of valve casing 32 downstream of the valve
seats 39.
eackflow preventor 44 is preferably made of a resilient,
elastomeric material, such as rubber. Figure 7A shows that
preventor 44 is shaped like a hollow bell. A cylindrical
base portion 46 has an outer diameter less than housing bore
14. The inner diameter of base portion 46 is large enough to
be stretched over the upper portion 34 of valve casing 32 on
operating rod 30 during installation, but small enough to
seal effectively against water pressure when seated in groove
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45. Thus, preventor 44 can be easily replaced if it becomes
worn or damaged.
Thin, flexible inner and outer side walls 48, 51 extend
downstream and diagonally outward from base portion 46 toward
outlet port 24 to terminate in a triangular radial cross
sectional shaped flange 50 which in turn terminates in a
pointed cylindrical lip portion 52. In the free state of
preventor 44, lip 52 normally engages housing bore 14 to seal
against flow. Walls 48 and 51 constitute the opening of the
bell shape and they encompass a hollow interior 54, which
accommodates the valve casing 32 on rod 30 and the deflection
or crimping of walls 48 and 51 when necessary.
Walls 48 and 51 and interior 54 present areas against
which water pressure can act, forcing preventor 44 to crimp
or expand in response to flow or backflow, respectively.
Outer wall 51 presents an angled surface against which, under
normal conditions, the pressure of inlet flow will act to
force, deflect, or crimp preventor 44 toward the central axis
of bore 14. Lip 52 is forced out of sealed engagement with
the walls of bore 14 and water from the inlet is permitted to
flow over preventor 44 to outlet port 24. This normally
flowing condition of hydrant 10 is shown in Figures 3 and 7B.
On the other hand, when downstream pressure urges backflow,
inner wall 48 and hollow interior 54 react to the
backpressure by expanding outwardly from the central axis of
bore 14. Lip 52 is forced back into sealed engagement with
the walls of bore 14. Whenever the effects of downstream
pressure are greater on preventor 44 than the forces from
inlet flow, it will automatically seal off bore 14 to prevent
backflow as shown in Figures 4 and 7A.
Figures 2-4 show that, in the preferred embodiment, the
flange size is selected to achieve a slip fit with bore 14.
Therefore, valve assembly 26 can be easily installed,
rotated, and removed. No backflow may leak past preventor 44
because it seals against the walls of housing bore 14 in its
naturally expanded state.
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Figure 3 shows inlet pressure deflecting the upstream-
directed surfaces of flange 50 away from the wall of bore 14
and toward the central axis of the same. This deflection or
crimping allows water to flow from inlet 22, around backflow
preventor 44, to outlet port 24. Therefore, hydrant 10
supplies water in the usual manner with minimal obstruction.
Preventor 44 is crimped by inlet pressure to lay just above
the upper portion 34 valve casing 32.
Figure 4 shows how the backflow preventor 44 works when
the downstream pressure (at outlet port 24) is greater than
inlet pressure. The stronger pressure from flow in an
upstream direction forces the flange 50 outward into sealed
engagement with the wall of bore 14. This prevents backflow
from the outlet 24 to the inlet 22. Contamination is
avoided, whether backpressure backflow or back siphonage
occurs. Further, this invention enhances the conventional
function of vacuum breaker 25, and creates an effective anti-
siphonage phenomenon. An unexpected result is that this
invention also creates an effective backpressure backflow
phenomenon. In addition, the ability of the backflow
preventor to collapse during normal flow as shown in Fig. 7B
permits the hydrant to be automatically flushed to free
itself of any debris in the water, and therefore is
essentially free of fouling.
Figures 8 through 11A show several modifications of
valve casing 32. Where these modified valve casings have
structure similar to that of valve casing 32, like numerals
will be used.
Figures 8 and 8A show valve casing 32A which has an
annular shoulder 47 thereon. A peripheral lip 47A extends
outwardly over a portion of the annular groove 45. The
backflow preventor 44A has a circular recess 47B to receive
the peripheral lip 47A.
Valve casing 32B is shown in Figures 9 and 9A. Annular
shoulder 47 terminates in a horizontally disposed V-shaped
recess 49A. Backflow preventor 44B has a V-shaped edge 49B
to fit into the recess 49A of valve casing 32B (Figure 9A).
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Valve casing 32C is shown in Figures 10 and 10A.
Shoulder 47 has a rectangular shaped peripheral notch 45A
therein. Figure 10A shows backflow preventor 44 mounted in
annular groove 45 but with a clamping band 45B extending
therearound. Band 45B has a horizontal flange 45C and a
vertical flange 45D. Flange 45C embraces the outside of one
end of backflow preventor 44 with the flange 45D extending
into the peripheral notch 45A. Band 45B is of continuous
construction and serves to clamp backflow preventor 44 to the
valve casing 32C.
Figure 11A shows backflow preventor 44 mounted on valve
casing 32D with a clamping band 45E which is one dimensional
and corresponds essentially to the flange 45C of clamping
band 45B.
Figure 11 shows valve casing 32D without the backflow
preventor 44 mounted thereon. Shoulder 47 has a circular
bead 45F thereon to enhance the tight connection between the
valve casing 32D and the backflow preventor 44. When
backflow preventor 44 is mounted on the valve casing 32D of
Figure 11, the use of clamping band 45E is optional. If
backflow preventor 44 is used when the bead 45F is not used,
the band 45E adds additional assurance that the backflow
preventor will not be removed from the valve casing.
The various alternative valve casing and backflow
preventor configurations shown in Figures 8 through 11A serve
to guarantee that the backflow preventor will not be removed
from the valve casing even during periods of high fluid
pressure.
The devices of Figures 8-11A are mounted within the
hydrant in the same manner as the valve casing 32 described
generally in Figures 1-7B.
From the foregoing, it is seen that this invention will
achieve at least all of its stated objectives.
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