Note: Descriptions are shown in the official language in which they were submitted.
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ANTI-BACKFLOW VALVE
BACKGROUND OF THE INVENTION
Field of Invention
The present invention relates to a technical field of anti-backflow valves for
water-supply facilities, and more particularly to an anti-backflow valve
structure having a
good operational sensitivity and a high degree of design freedom.
Related Art
Generally, in order to maintain pressure equilibrium between cold and hot
water supply
flow passages within a faucet and prevent a back flow, a check valve is
additionally
provided in the flow passages, for ensuring a smooth water outflow. In
addition, in flow
passages of a pull-out faucet, in order to prevent a back siphonage, a check
valve is
additionally provided in the flow passages as well.
FIG 1 is a schematic view of a conventional check valve being assembled on a
faucet
pipe. Referring to FICi 1, a cold water inlet 81 and a hot water inlet 82 of a
faucet 8 are
respectively provided with one check valve 9, so as to prevent a back flow.
FIG 2 is a schematic structural view of the check valve. Referring to FIG 2,
the check
valve 9 has a valve seat 91. The valve seat 91 has an accommodating chamber 92
therein.
The accommodating chamber 92 has an inlet 921 at one end thereof, and a cover
93 at the
other end. The cover 93 has a bushing 931 in a center thereof. A plurality of
ribs 932 is
extended around the bushing 931, so as to form a plurality of openings 933 on
the cover 93.
The accommodating chamber 92 has a plug 94 disposed therein. The plug 94 is
provided
with an 0-ring 941 at one end thereof, and a rod 942 at the other end. The rod
942 is
inserted into the bushing 931. A spring 95 is provided between the plug 94 and
the cover
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93, and the plug 94 is pushed to press against an end face 922 of the
accommodating
chamber 92 adjacent to the inlet 921 by the elastic force of the spring 95,
thereby achieving
a normally enclosed state.
FIG. 3 is a schematic view of operations of the above check valve 9. Referring
to FIG
3, when the faucet is open, a water flow flows in via the inlet 921. At this
point, the water
pressure pushes the plug 94 to compress the spring 95, so as to cause the 0-
ring 941 of the
plug 94 to depart from the end face 922 of the accommodating chamber 92. In
this manner,
the water flow can enter the accommodating chamber 92 via the inlet 921, then
flow
through a gap between the plug 94 and an inner wall of the accommodating
chamber 92,
and finally flow into the faucet via the opening 933 of the cover 93.
When the faucet is closed, the water pressures at two ends of the check valve
9 are
equal. The plug 94 is pressed against the end face 922 of the accommodating
chamber 92
under the action of the spring 95, thus achieving the enclosed state.
Alternatively, when
the pipe pressure within the faucet is larger than the water-inlet pressure
(for example, when
cold water and hot water mixed-flows), the check valve 9 also achieves the
enclosed state
under the action of the spring 95, thereby preventing a back flow.
However, the above check valve structure has the following problems.
1. Since the water flow has to flow through the accommodating chamber via the
gap
between the plug and the inner wall of the accommodating chamber, the plug has
to be
designed to be of a certain size smaller than the inner wall of the
accommodating chamber.
Moreover, since the 0-ring is engaged on the plug and used to press against
the end face of
the accommodating chamber so as to achieve the enclosed state, the end face
has to be of a
certain size smaller than the plug, which causes the inlet to have a fairly
small size. In this
manner, the active area of the water flow on the plug through the inlet
correspondingly
becomes small, which will cause the motion of the plug to become insensitive
and thus
cause a problem of water flux control.
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2. The check valve is pressed against the end face of the acconunodating
chamber
by the 0-ring of the plug so as to block the water flow. In order to achieve
the effect of
blocking the water flow, a spring having a large elastic coefficient is
commonly used to
increase the force of the 0-ring against the end face. After the acting force
of the spring is
increased, a pressure required for the water flow to push off the plug is
correspondingly
increased, which will cause the motion of opening the check valve to become
insensitive.
3. As described above, the sizes of the accommodating chamber and the plug and
the inlet are associated with one another. If it is desired to change a
maximum water flux
of the check valve, the sizes of the accommodating chamber and the plug and
the inlet may
need to be simultaneously changed, which results in a low degree of design
freedom of the
check valve. In other words, for check valves designed for different fluxes,
plugs and
valve seats thereof (having an accommodating chamber and an inlet therein)
cannot be
alternatively used, which increases the manufacturing and inventory costs as
well.
Therefore, there is surely a need for further improving the above check valve
structure.
SUMMARY OF THE INVENTION
The present invention is directed to an anti-backflow valve having a good
operational
sensitivity and a high degree of design freedom, which can solve the above
problems.
The present invention is also directed to an anti-backflow valve, which can
effectively
reduce the manufacturing and inventory costs.
In order to achieve the above objectives, the present invention provides an
anti-backflow valve, which includes a valve seat and a plug slidingly disposed
in the valve
seat. The valve seat has a ring portion protruding inwards at a middle section
of a flow
passage penetrating therethrough. The ring portion has a seat portion extended
outwards
on one side thereof. The plug is sleeved into the ring portion in a slidable
manner. The
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plug has an accommodating chamber recessed inwards. The accommodating chamber
has
an opening radially penetrating through the plug at one end thereof distant
from an inlet.
The plug has a protruding portion at one end thereof adjacent to the inlet. An
outer
diameter of the protruding portion is larger than an inner diameter of the
ring portion. The
plug has an 0-ring engaged thereon at one end thereof adjacent to the
protruding portion.
An elastic element is provided between the protruding portion and the ring
portion such that
the 0-ring is forced to press against the seat portion by an elastic force
thereof.
Therefore, in the present invention, the inner wall of the accommodating
chamber and
the protruding portion can jointly form an active area for the water flow to
push the plug, so
as to enlarge the active area of the water flow, thereby improving the
sensitivity of sliding
of the plug and achieving a more smooth control over the water flux.
On the other hand, the seat portion is a recessed cone-shaped structure. The
conical
surface configuation can improve the sealing effect between the 0-ring and the
seat portion.
Therefore, a good water-flow blocking effect can be achieved without using a
spring having
a large elastic coefficient, which reduces the force required for the water
flow to push off
the plug, thereby improving the sensitivity of sliding of the plug.
Moreover, in the structure of the present invention, a maximum water flux of
the
anti-backflow valve can be changed simply by changing the number and size of
the opening,
and the remaining portions and sizes of the structure need not to be changed.
In this
manner, the manufacturing and inventory costs are effectively reduced and the
degree of
design freedom of the product is improved.
In order to make the foregoing and other objectives, features, and advantages
of the
present invention comprehensible, an embodiment is described in detail below
with
reference to the accompanying drawings.
Definitely, the present invention allows some variations on certain parts or
arrangement
of the parts, but the embodiment selected in the present invention is
illustrated in detail in
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the specification, and the construction thereof is shown in the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fiully understood from the detailed
description
given herein below for illustration only, and thus are not limitative of the
present invention,
and wherein:
FICi. 1 is a schematic view of a conventional check valve being assembled on a
faucet
pipe;
FICi. 2 is a schematic structural view of the check valve;
FIG. 3 is a schematic view of operations of the check valve;
FIG. 4 is a three-dimensional exploded view of the present invention;
FICi. 5 is a combined cross-sectional view of the present invention; and
FICi. 6 is a schematic view of a using state of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
As for the technical means adopted in the present invention to achieve the
above
objective, a detailed illustration is given below through the embodiment and
accompanying
drawings.
FIG 4 is a three-dimensional exploded view of the present invention, and FIG 5
is a
combined cross-sectional view of the present invention. An anti-backflow valve
of the
present invention is suitable for being assembled into a pipe of a water-
supply facility, for
example, into a pipe within a faucet or a pipe within a shower assembly.
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An anti-backflow valve of the present invention includes a valve seat 1 and a
plug 2
slidingly disposed in the valve seat 1. An outer edge of the valve seat 1 has
an annular
groove 10 recessed therein, and the annular groove 10 has a sealing ring 101
disposed
therein. The valve seat 1 has a flow passage 11 penetrating therethrough. A
middle
section of the flow passage 11 has a ring portion 12 protruding inwards. The
ring portion
12 has a seat portion 13 extended outwards on one side thereof. The seat
portion 13 is a
recessed cone-shaped structure and has a large-diameter portion 131 on one
side thereof
distant from the ring portion 12. The ring portion is provided with an annular
flange 121
extended on one side thereof relative to the seat portion 13.
The plug 2 is sleeved into the ring portion 12 and the annular flange 121 in a
slidable
manner. The plug 2 has an accommodating chamber 21 recessed inwards. The
accommodating chamber 21 is formed with an inlet 211 at one end of the plug 2,
and has
four openings 22 disposed radially opposite to one another and radially
penetrating through
the plug 2 at one end thereof distant from the inlet 211. The plug 2 has a
protruding
portion 23 at one end thereof adjacent to the inlet 211. An outer diameter of
the protruding
portion 23 is larger than an inner diameter of the ring portion 12. An elastic
element is
provided between the protruding portion 23 and the ring portion 12, which is a
spring 24 in
this embodiment. The spring 24 is sleeved at the annular flange 121. A portion
of the
plug 2 penetrating through the ring portion 12 has an annular groove 25 for an
0-ring 26 to
be engaged. An outer diameter of the 0-ring 26 is larger than the inner
diameter of the
ring portion 12 and smaller than the large-diameter portion 131 of the seat
portion 13.
Therefore, the 0-ring 26 is forced to press against the seat portion 13 by an
elastic force of
the spring 24 so as to achieve an effect of blocking the flow passage 11. In
addition, the
plug 2 has a recessed portion 27 in a center of one end thereof adjacent to
the 0-ring 26.
FIG 6 is a schematic view of a using state of the present invention. Referring
to FIG
6, the anti-backflow valve of the present invention is disposed in a pipe 3 of
a water-supply
facility by the valve seat 1. When disposing, the end of the plug 2 having the
protruding
portion 23 is disposed adjacent to an upstream side of the water-supply pipe,
and a sealing
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effect is achieved between the valve seat 1 and the pipe 3 by the sealing ring
101 engaged at
the outer edge of the valve seat 1.
When the water-supply facility is open, the water flow flows in via the flow
passage 11
of the valve seat 1. At this point, the water pressure simultaneously pushes
an inner wall
of the accommodating chamber 21 and the protruding portion 23 of the plug 2 to
compress
the spring 24, so as to enable the plug 2 to slide along the ring portion 12
and the annular
flange 121 thereof, thereby causing the 0-ring 26 to depart from the seat
portion 13. In
this manner, the water flow can flow through the seat portion 13 via the
opening 22, enter
the other side of the flow passage 11, and then flow into the water-supply
facility. When
the water-supply facility is closed, water pressures of the flow passage 11 at
two sides of the
plug 2 are equal. The plug 2 moves back under the elastic force of the spring
24, which
forces the 0-ring 26 to press against the seat portion 13 so as to achieve the
enclosed state.
Alternatively, when the pipe pressure within the water-supply facility is
larger than the
water-inlet pressure (for example, when cold water and hot water mixed-flows),
the
anti-backflow valve achieves the enclosed state as well, thereby preventing a
back flow.
The structure of the present invention has the following features.
1. Since the water flow passes through the plug 2 via the opening 22 and then
enter
the other side of the flow passage 11 via the seat portion 13, and the plug 2
has the
protruding portion 23 at one end of the inlet 211 of the accommodating chamber
21, both
the inner wall of the accommodating chamber 21 and the protruding portion 23
can become
the active area for the water flow to push the plug 2. Therefore, the active
area of the water
flow can be greatly increased, thereby improving the sensitivity of sliding of
the plug 2 and
achieving a more smooth control over the water flux.
2. Since the 0-ring 26 of the plug 2 of the present invention is pressed
against the
seat portion 13 so as to block the water flow and the conical surface form
formed by the
seat portion 13 having the recessed cone-shaped structure has a pushing effect
on the 0-ring
26, a better sealing effect between the 0-ring 26 and the seat portion 13 is
achieved.
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Therefore, a good water-flow blocking effect can be achieved in the present
invention
without using a spring having a large elastic coefficient. That is to say, the
force required
for the water flow to push off the plug is reduced, and the sensitivity of
sliding of the plug 2
is thus improved.
3. Different countries or regions have different specifications on water
utilization,
for example, on the maximum flux of the water-supply facility. However, for
the structure
of the present invention, the maximum water flux of the anti-backflow valve
can be
changed simply by changing the number and size of the opening 22, and the
remaining
portions and sizes of the structure need not to be changed. In this manner,
the
manufacturing and inventory costs is effectively reduced and the degree of
design freedom
of the product is improved.
Therefore, the anti-backflow valve of the present invention can surely achieve
the
objectives of improving the operational sensitivity and degree of design
freedom.
The disclosure of the embodiment is intended to illustrate the present
invention, but not
to limit the present invention, so the variation of cited values or
replacement of equivalent
elements still falls within the scope of the present invention.
Through the above detailed descriptions, it is apparent to those skilled in
the art that the
present invention can surely achieve the above objectives, which conforms to
the provisions
of the patent law, so as to apply for a patent application.
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