TECHNICAL FIELD
The present disclosure relates to a valve mechanism for regulating flow in a pipe line.
Particularly, the present disclosure relates to a valve mechanism for creating a bypass
for the flow when a pipe line, conveying fluid/semi-solid material, is under
maintenance or is non-functional.
BACKGROUND OF THE PRESENT DISCLOSURE
The information in this section merely provides background information related to the
present disclosure and may not constitute prior art(s).
Generally pipelines for waste flow are provided with a valve mechanism to regulate
and control the waste flow through the pipeline. More specifically, valve mechanisms
are used to bypass the waste flow when a main flow line (also referred to as P-trap
hereinafter), through which the waste flows under normal conditions, is nonfunctional
due to jamming/clogging or is under maintenance.
Conventionally, the P-trap, such as in case of toilet systems in locomotives, is
connected to the main flow pipeline and is normally used for the outflow of waste
from the main pipeline. Under certain conditions when the P-trap is jammed due to
litter or other solid matter getting stuck, the P-trap is bypassed by means of a valve
connected directly to the main flow pipeline to expel the litter or solid matter from the
system. For such purpose, a Quarter Turn Ball valve is employed.
A ball valve comprises a valve-housing, a valve-ball in the housing that can be turned
between an open and a closed condition, pipe connectors connected to opposite ends
of the housing, and valve seats located within the housing and resiliently urged into
sealing engagement with the ball. O-ring seals are provided between the valve seats
and the inside periphery walls of said recesses in the adaptors, and the valve seats
carry non-metallic, for example polymers (such as nylon, Teflon etc.), sealing rings in
engagement with the ball. The ball valve provides are leak proofing and can be
opened/closed quickly. Therefore, when the operator actuates the valve to open it, the
3
ball moves/turns about a closed condition to allow the accumulated waste to pass
through the valve.
One major problem associated with the existing Quarter Turn Ball Valve is that it has
a faulty actuation mechanism. Opening/closing the ball valve due to a number of
mechanical components is cumbersome and sometimes results in the actuation system
getting jammed or stuck frequently. Further, area of contact between the valve-ball
and interior of valve-housing with which the valve ball remains in contact is more.
With permeation of semi-solid waste between clearances of the valve-ball and the
valve-housing, the force required to operate the ball valve increases significantly. This
in turn results in a decreased credibility of the ball valve mechanism for the purpose
of cleaning/maintenance of the waste flow pipeline.
In other words, researchers have developed a user friendly and technically advance
valve mechanism for regulating flow in a pipe line. More specifically, in light of
foregoing discussion, it is necessary to develop an improved valve mechanism for
regulating flow in a pipe line to overcome one or more limitations stated above.
SUMMARY
One or more drawbacks of conventional valve mechanism as described in the prior art
are overcome and additional advantages are provided through the improved valve
mechanism as claimed in the present disclosure. Additional features and advantages
are realized through the technicalities of the present disclosure. Other embodiments
and aspects of the disclosure are described in detail herein and are considered to be a
part of the claimed disclosure.
In one non-limiting embodiment of the present disclosure, there is provided an
improved valve mechanism for regulating flow in a pipeline. The improved valve
mechanism comprises a valve unit and a drive unit; the valve unit comprising an
adapter plate, a top plate and housing; and a passage extending through the adapter
plate, top plate and the housing. The valve mechanism also comprises a slide plate
adapted to be received in the housing and being movable between a closed condition
and an open condition of the valve unit wherein the closed condition is defined as the
4
position in which the passage is completely covered by the slide plate; and the open
condition is defined as the position in which slide plate is completely removed from
the passage. The valve mechanism further comprises a drive mechanism for sliding
the slide plate between open condition and closed condition of the valve unit.
In an embodiment of the present disclosure, the adapter plate comprises a first upper
face, a first lower face and a first hole; the first upper face is being connected to a Ptrap
of a pipe line; and the first lower face is being connected to a second upper face
of the top plate.
In another embodiment of the present disclosure, the top plate comprises second
upper face, second lower face and second hole; the second upper face being connected
with the first lower face of the adapter plate; and the second lower face is connected
to the third upper face of the housing.
In a further embodiment of the present disclosure, the adapter plate, the top plate and
the housing each comprise a hole that defines the passage for flow when the holes of
the top plate, bottom plate and housing are aligned.
In one more embodiment of the disclosure, the slide plate is received movably in
guide seals mounted along sides of the housing.
In a still further embodiment of the present disclosure, the slide plate comprises a
proximal end and a distal end; the proximal end being adapted to open/close the
passage for waste flow from the main flow pipe to the retention tank; and the distal
end being configured with a drive unit for slidably moving the slide plate during
actuation of the valve mechanism.
It is to be understood that the aspects and embodiments of the disclosure described
above may be used in any combination with each other. Several of the aspects and
embodiments may be combined together to form a further embodiment of the
disclosure.
The foregoing summary is illustrative only and is not intended to be in any way
limiting. In addition to the illustrative aspects, embodiments, and features described
5
above, further aspects, embodiments, and features will become apparent with
reference to the drawings and the following detailed description.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The novel features and characteristics of the disclosure are set forth in the appended
description. The disclosure itself, however, as well as a preferred mode of use, further
objectives and advantages thereof, will best be understood by reference to the
following detailed description of an illustrative embodiment when read in conjunction
with the accompanying figures. One or more embodiments are now described, by way
of example only, with reference to the accompanying figures wherein like reference
numerals represent like elements and in which:
Figure 1 shows a perspective view of the existing Quarter Turn Ball valve
mechanism used in waste flow pipelines.
Figure 2 illustrates the present valve mechanism for use waste flow pipelines in an
embodiment of present disclosure.
Figure 3 shows an exploded view of the various sub-parts and sub-assemblies that are
contained in the present valve mechanism according to one more embodiment of
present disclosure.
Figure 4 depicts an isometric view of the valve mechanism according another
embodiment of present disclosure.
Figure 5 depicts a sectional view of the slide plate and locking wedge of the housing
in an open condition of the valve unit according to the above described embodiment
of the present disclosure.
Figure 6 depicts a sectional view of the slide plate and locking wedge in closed
condition of the valve unit according to the above described embodiment of the
present disclosure.
6
Figure 7 depicts a sectional view of the guide seal and the slide plate according to
another embodiment of the present disclosure.
Figure 8 depicts an isometric view of the valve unit in closed condition according to
another embodiment of the present disclosure.
Figure 9 shows an isometric view of the valve unit in partially open condition
according to yet another embodiment of the present disclosure.
Figure 10 illustrates the valve unit in completely open condition according to one
more embodiment of the present disclosure.
Figure 11 depicts an alternate embodiment of the present disclosure whereby the
valve unit is in closed condition.
Figure 12 shows the alternate embodiment of the present disclosure whereby the
valve unit is in an intermediate condition.
Figure 13 illustrates the alternate embodiment of the present disclosure whereby the
valve unit is in open condition.
The figures depict embodiments of the disclosure for purposes of illustration only.
One skilled in the art will readily recognize from the following description that
alternative embodiments of the assemblies and methods illustrated herein may be
employed without departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION
While the invention is subject to various modifications and alternative forms, specific
embodiment thereof has been shown by way of example in the figures and will be
described below. It should be understood, however that it is not intended to limit the
invention to the particular forms disclosed, but on the contrary, the invention is to
cover all modifications, equivalents, and alternative falling within the spirit and scope
of the invention as defined by the appended claims.
7
Before describing in detail the various embodiments of the present disclosure it may
be observed that the novelty and inventive step that are in accordance with the present
disclosure resides in a valve mechanism for regulating flow in a pipeline. It is to be
noted that a person skilled in the art can be motivated from the present disclosure and
can perform various modifications. However, such modifications should be construed
within the scope of the invention.
Accordingly, the drawings are showing only those specific details that are pertinent to
understanding the embodiments of the present disclosure so as not to obscure the
disclosure with details that will be readily apparent to those of ordinary skill in the art
having benefit of the description herein.
The terms “comprises”, “comprising”, or any other variations thereof, are intended to
cover a non-exclusive inclusion, such that an assembly, setup, system, device
that comprises a list of components does not include only those components but
may include other components not expressly listed or inherent to such system or
device or setup. In other words, one or more elements in the system or apparatus or
device proceeded by “comprises a” does not, without more constraints, preclude the
existence of other elements or additional elements in the assembly or system or
apparatus. The following paragraphs explain present disclosure. The invention in
respect of the same may be deduced accordingly.
Accordingly, it is an aim of the present disclosure to provide a toilet system for
locomotives such as trains. Another aim of the present disclosure is to provide a valve
mechanism for regulating flow in waste flow pipelines. One more aim of the present
disclosure is to provide a valve mechanism that overcomes or at least reduces the
problem of jamming of the valve.
Accordingly, the present disclosure provides a valve mechanism for regulating flow
through a pipe line; the valve mechanism comprising a valve unit and a drive unit; the
valve unit comprising an adapter plate, a top plate and housing; and a passage
extending through the adapter plate, top plate and the housing. The valve mechanism
also comprises a slide plate adapted to be received in the housing and being movable
8
between a closed condition and an open condition of the valve unit wherein the closed
condition is defined as the position in which the passage is completely covered by the
slide plate; and the open condition is defined as the position in which slide plate is
completely removed from the passage. The valve mechanism further comprises a
drive mechanism for sliding the slide plate between open condition and closed
condition of the valve unit.
In an embodiment of the present disclosure, the adapter plate comprises a first upper
face, a first lower face and a first hole; the first upper face is being connected to a Ptrap
of a main pipe line; and the first lower face is being connected to a second upper
face of the top plate.
In another embodiment of the present disclosure, the top plate comprises second
upper face, second lower face and second hole; the second upper face being connected
with the first lower face of the adapter plate; and the second lower face is connected
to the third upper face of the housing.
In a further embodiment of the present disclosure, the adapter plate, the top plate and
the housing each comprise a hole that defines the passage for flow when the holes of
the top plate, bottom plate and housing are aligned.
In yet another embodiment of the present disclosure, the slide plate is received
movably in the guide seals of the housing.
In one more embodiment of the present disclosure, the peripheral edge of the housing
comprises a locking wedge having a slant side.
In another embodiment of the present disclosure, the slide plate comprises a proximal
end and a distal end; the proximal end being adapted to open/close the passage for
waste flow from the main flow pipe to the retention tank; the distal end being
configured with a drive unit for slidably moving the slide plate during actuation of the
valve mechanism; and the peripheral side comprising a tapered portion.
9
In one further embodiment of the present disclosure, in the closed condition of the
valve unit, the tapered portion of the peripheral side of the slide plate forms mating
contact with the slant side of the locking wedge.
Accordingly the present disclosure provides a toilet system comprising a main flow
pipe being connected with a retention tank through a secondary flow pipe by means of
a P-trap; and a waste disposal tank being connected with the main flow pipe by means
of a valve mechanism; wherein the valve mechanism is configured to allow flow from
the main flow pipe to the secondary flow pipe through the P-trap to the retention tank
in the closed condition of the valve unit; and the valve mechanism being configured to
allow flow from the main flow pipe to the waste disposal tank by bypassing the P-trap
in the open condition of the valve unit.
Reference will now be made to a valve mechanism and is explained with the help of
figures. The figures are for the purpose of illustration only and should not be
construed as limitations on the assembly and mechanism of the present disclosure.
Wherever possible, referral numerals will be used to refer to the same or like parts.
Figure 2 is an exemplary embodiment of the present disclosure which illustrates a
perspective view of a toilet system comprising a main flow pipe (M) being connected
with the retention tank through a secondary flow pipe (N) by means of a P-trap; and to
a waste disposal tank by means of a valve mechanism. The valve mechanism
comprises a valve unit (VU) and a drive unit (DU) wherein the valve unit (VU) is
mounted with the main pipe line (M) to regulate the flow there through. In the
mounted condition, valve mechanism is configured to allow flow from the main flow
pipe (M) to the retention tank through secondary flow pipe (N) through the P-trap in
the closed condition of the valve unit; and the valve mechanism being configured to
allow flow from the main flow pipe (M) to the waste disposal tank by bypassing the
P-trap in the open condition of the valve unit.
As shown in figures 3 and 4, the valve unit (VU) comprises an adapter plate (1)
having a first upper face (1a); a first lower face (1b) and a first hole (1c). The valve
unit (VU) further comprises a top plate (2) corresponding to the top plate (2). The top
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plate (2) has a second top face (2a), a second bottom face (2b) and a second hole (2c).
In the assembled condition of the valve unit (VU), the top plate (2) is disposed
between the adapter plate (1) and housing (3). The housing (3) comprises a third
upper face (3a), a third lower face (3b) and a hole (3c). In the assembled condition,
the first upper face (1a) of the adapter plate (1) is connected to the P-trap of a main
pipe line (M) and the first lower face (1b) is connected with the second upper face
(2a) of the top plate (2). The third upper face (3a) of the housing (3) is connected with
the second lower face (2b) of the top plate (2) and the third lower face (3b) of the
housing (3) is being connected to a retention tank. The valve unit (VU) further
comprises a three seals; a round seal (S1) being disposed between the first lower face
(1b) of the adapter plate (1) and second upper face (2a) of the top plate (2); two wiper
seals (S2), one being disposed between the second lower face (2b) of the top plate (2)
and an upper face of the slide plate and the other disposed between a lower face of the
slider plate and third upper face (3a) of the housing (3); and two guide seals (S3)
being fixed on the housing (3) thereby providing sealing against leakage. The valve
unit (VU) is mounted with the main pipe line to regulate the flow there through. The
top plate (2), the housing (3) and the bottom plate (2) are mounted such that the first
hole (1c), the second hole (2c) and the third hole (3c) are aligned so as to define a
passage (P) for the flow of a semi-solid/liquid substance such that the passage of the
valve unit (VU) is aligned with the main pipe and an opening to the waste disposal
tank.
As shown in figures 5-7, the housing (3) comprises a plurality of sides (S), defined
internally along the peripheral edges (3d). A slide plate (4) is received movably in the
housing (3) such that the slide plate (4) is slidable in the guide seal (S3) mounted
along the sides (S) in the housing. In other words, peripheral sides (4d) & (4e) of the
slide plate (4) is supported in the guide seals mounted in the housing (3); the first
peripheral side (4c) having first tapered portion (T1) and second peripheral sides (4d)
& (4e) having second tapered portion (T2). In an embodiment of the present
disclosure, the sides (S) are provided with guide seals (S3) made of a polymeric
material such Teflon etc., for avoiding metal to metal contact during sliding motion of
the slide plate (4); thereby leading to decreased friction during sliding of the slide
plate (4) eventually resulting in less mechanical force required to slide the same. A
locking wedge (W) is formed on the peripheral edge of the housing (3d); the locking
11
wedge (W) having a slant side (WS). The gradient of the slant side (WS) is
corresponding to the gradient of first tapered portion (T1) of the slide plate (4) such
that in the closed condition of the valve unit (VU), the first tapered portion (T1) of the
first peripheral side (4c) of the slide plate (4) forms mating contact with the slant side
(WS) of the locking wedge (W). The slide plate is capable of sliding linearly along the
length (L) of sides (S) of the housing (3). The slide plate comprises a proximal end
(4a) and distal end (4b). In the mounted position, the slide plate (4) is received in the
housing (3) such that the proximal end (4a) of the slide plate (4) slides between the
second lower face (2b) and third upper face (3a) so as to open/close the third hole
(3c); thereby resulting in opening/closing of the passage (P) for waste flow thus
regulating the flow of waste directly from the main flow pipe (M) to the waste
disposal tank i.e. by by-passing the P-trap.
During the sliding motion of the slide plate (4), entry of unwanted waste into the
valve unit (VU) is prevented by the round seal (S1) provided between the second
upper face (2a) and the first lower face (1b). In the closed condition, the slide plate (4)
is locked in place with the locking wedge (W) in the housing (3). During movement
of the slide plate (4) from the open condition of the valve unit (VU) to the closed
condition, the first tapered portion (T1) of the first peripheral side (4c) of the slide
plate (4) lifts the round seal (S1) in the upward direction towards the adapter plate (1).
The upward movement of the round seal (S1) in turn leads to compression of the ORing
(10); thereby creating a positive seal pressure between the slide plate (4) and the
round seal (S1), which stops any waste from leaking into the valve unit (VU) in the
closed condition.
The distal end (4b) of the slide plate (4) is adapted to be coupled with the drive unit
(DU) for sliding/moving the slide plate (4) when an actuation force is applied. The
drive unit (DU) comprises a rack (6) which is rigidly secured with the distal end (4b)
of the slide plate (4) and comprises a plurality of teeth for operatively engaging with a
pinion (5). The pinion (5) is mounted on a drive shaft (7) and is rotatable with the
rotation of the drive shaft (7); the drive shaft (7) being coupled with an operating
means such as a pulley, electric motor, etc. In an embodiment of the present
disclosure, two bearings (9) are mounted on both sides of the pinion (5) to ensure that
the pinion (5) has rotary motion only in a direction parallel to the rack. Collar (8)
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restricts the longitudinal movement of the pinion (5) during operation of the drive unit
thereby enhancing accuracy during actuation.
According to a still further embodiment of the present disclosure, as shown in figures
8-10, the drive unit (DU) is rotated by means of a pulley (15) which is mounted on the
drive shaft. The pulley (15) can be rotatable by means of a rope, wire etc. As shown in
figure 8, in closed condition of the valve unit the proximal end of the slide plate (4)
covers the hole (3c) of the housing (3) thereby obstructing the passage (P) for the flow
of waste. Thus, in the closed condition of the valve unit, waste passes from main pipe
line to retention tank through the secondary pipe line (N) and through the P-Trap.
Under unwanted circumstances such as blockage/maintenance of P-trap, when the
user actuates the pulley (15) by means of a rope, wire or any other actuation medium,
the shaft (7) starts rotating. The rotation of the shaft (7) leads to the rotation of the
pinion (5) in the direction of rotation of the pulley. This results in actuation of the
rack in a linear direction. This movement leads to a movement of the slide plate (4) in
the guide seals (S3) present in the housing (3) such that the proximal end (4a) slides
towards the pinion (5). This leads to opening of the passage for the flow of litter/waste
through the valve unit. Figure 9 depicts an intermediate position when the valve unit
is opening from a closed condition. On further rotation of the pulley, the proximal end
(4a) of the slide plate (4) moves towards the pinion (5) until the passage (P) of the is
completely open for passage of waste i.e. open condition of the valve unit as shown in
figure 10.
In an alternate embodiment of the present disclosure, as shown in figures 11-13, the
drive unit (DU) is actuated by a scotch yoke mechanism. The scotch yoke mechanism
comprises a crank (11), crankshaft (12) and a sliding actuator (13) being configured
with the crankshaft (12). An actuation slot (14), extending in the lateral direction, is
provided at the distal end of the slide plate. The term ‘lateral direction’ herein refers
to a direction perpendicular to the direction of sliding motion of the slide plate, in the
plane of the slide plate. Accordingly, a slot is provided on the top plate to
accommodate the positions of the sliding actuator (13), in the open and closed
conditions of the valve unit (VU). During actuation of the drive unit (DU), the
crankshaft (12) rotates thereby causing actuation of pulley. The pulley has the same
actuation mechanism for rotation as the rack and pinion mechanism. The crankshaft
13
(12) is also configured to a bearing which enables full transfer of torque from the
pulley to the crankshaft during actuation of the valve unit (VU). In the open condition
of the valve unit (VU), the slide plate stops at the end of the housing, thereby
eliminating the need of an open side in the housing to accommodate the distal end of
the slide plate (as shown in figure 13).
In one further embodiment of the present disclosure, the present valve mechanism can
be used for waste systems in toilets installed in locomotives such as buses and railway
coaches. In such an application, the valve mechanism can be automated using the
electrical/pneumatic system of the railway coaches thereby allowing a remote user to
actuate the drive unit (DU) of the valve mechanism. In other applications, the present
valve mechanism can be used in waste digesters in housing societies, portable toilets
etc.
List of reference numerals:
1 Adapter Plate
1a First Upper Face
1b First Lower Face
1c First Hole
2 Top Plate
2a Second Upper Face
2b Second Lower Face
2c Second Hole
3 Housing
3a Third Upper Face
3b Third Lower Face
3c Third Hole
3d Peripheral edges of the Housing
4 Slide Plate
4a Proximal End of Slide Plate
4b Distal End of Slide Plate
4c First Peripheral side of the Slide
Plate
4d,4e Second Peripheral sides of the Slide
Plate
5 Pinion
6 Rack
14
7 Drive Shaft
8 Collar
9 Bearing
10 O-Ring
11 Crank
12 Crankshaft
13 Sliding Actuator
14 Actuation Slot
15 Pulley
M Main Pipe line
N Secondary Pipe line
P Passage
S Side of the Housing
T1 First tapered portion
T2 Second tapered portion
W Locking Wedge
S1 Round Seal
S2 Wiper Seal
S3 Guide Seal
DU Drive Unit
VU Valve Unit
WS Slant Side
Equivalents:
With respect to the use of substantially any plural and/or singular terms herein, those
having skill in the art can translate from the plural to the singular and/or from the
singular to the plural as is appropriate to the context and/or application. The various
singular/plural permutations may be expressly set forth herein for sake of clarity.
It will be understood by those within the art that, in general, terms used herein, and
especially in the appended claims (e.g., bodies of the appended claims) are generally
intended as “open” terms (e.g., the term “having” should be interpreted as “having at
least,” etc.). It will be further understood by those within the art that if a specific
number of an introduced claim recitation is intended, such an intent will be explicitly
recited in the claim, and in the absence of such recitation no such intent is present. For
example, as an aid to understanding, the following appended claims may contain
usage of the introductory phrases “at least one” and “one or more” to introduce claim
15
recitations. However, the use of such phrases should not be construed to imply that
the introduction of a claim recitation by the indefinite articles “a” or “an” limits any
particular claim containing such introduced claim recitation to inventions containing
only one such recitation, even when the same claim includes the introductory phrases
“one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a”
and/or “an” should typically be interpreted to mean “at least one” or “one or more”);
the same holds true for the use of definite articles used to introduce claim recitations.
In addition, even if a specific number of an introduced claim recitation is explicitly
recited, those skilled in the art will recognize that such recitation should typically be
interpreted to mean at least the recited number (e.g., the bare recitation of “two
recitations,” without other modifiers, typically means at least two recitations, or two
or more recitations). It will be further understood by those within the art that virtually
any disjunctive word and/or phrase presenting two or more alternative terms, whether
in the description, claims, or drawings, should be understood to contemplate the
possibilities of including one of the terms, either of the terms, or both terms. For
example, the phrase “A or B” will be understood to include the possibilities of “A” or
“B” or “A and B.”
While various aspects and embodiments have been disclosed herein, other aspects and
embodiments will be apparent to those skilled in the art. The various aspects and
embodiments disclosed herein are for purposes of illustration and are not intended to
be limiting, with the true scope and spirit being indicated by the following claims.

We claim:
1. A valve mechanism for regulating flow through a pipe line; the valve
mechanism comprising a valve unit (VU) and a drive unit (DU); the valve unit
(VU) comprising:
an adapter plate (1);
a top plate (2);
a housing (3);
a passage (P) extending through the adapter plate (1), top plate (2), and
the housing (3);
a slide plate (4) adapted to be received in the housing (3) and being
movable between a closed condition and an open condition of the valve unit
(VU) wherein
the closed condition is defined as the condition in which the
passage (P) is covered by the slide plate (4); and
the open condition is defined as the condition in which slide
plate (4) is removed from the passage (P);
a drive mechanism (DU) for actuating the slide plate (4) between open
condition and closed condition of the valve unit.
2. The valve mechanism as claimed in claim 1, wherein the adapter plate (1)
comprises a first upper face (1a), a first lower face (1b) and a first hole (1c);
the first upper face (1a) is being connected to a P-trap of a main pipe
line (M); and
the first lower face (1b) is being connected to a second upper face (2a)
of the top plate (2).
3. The valve mechanism as claimed in claim 1, wherein the top plate (2)
comprises second upper face (2a), second lower face (2b) and second hole
(2c);
the second upper face (2a) being connected with the first lower face
(1a) of the adapter plate (1); and
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the second lower face (2b) is connected to third upper face (3a) of the
housing (3).
4. The valve mechanism as claimed in claim 1, wherein the adapter plate (1), top
plate (2), and the housing (3) each comprise holes (1c), (2c) and (3c) that
defines a passage (P) for flow when the holes of the adapter plate, top plate
and housing are aligned.
5. The valve mechanism as claimed in claim 1, wherein the slide plate (4) is
received movably in guide seals (S3) mounted along sides (S) of the housing
(3).
6. The valve mechanism as claimed in claim 1, wherein the peripheral edge (3d)
of the housing (3) comprises a locking wedge (W) having a slant side (WS).
7. The valve mechanism as claimed in claim 1, wherein the slide plate (4)
comprises a proximal end (4a), a distal end (4b), first peripheral side (4c) and
second peripheral sides (4d) & (4e);
the proximal end (4a) being adapted to open/close the passage (P) for
waste flow from the main flow pipe to the retention tank;
the distal end (4b) being configured with a drive unit (DU) for slidably
moving the slide plate (4) during actuation of the valve mechanism;
and
the first peripheral side (4c) having first tapered portion (T1) and
second peripheral sides (4d) & (4e) having second tapered portion
(T2).
8. The valve mechanism as claimed in claim 1, wherein in the closed condition
of the valve unit (VU), the first tapered portion (T1) of the slide plate (4)
forms mating contact with the slant side (WS) of the locking wedge (W).
9. A toilet system comprising a main flow pipe (M) being connected with a
retention tank through secondary flow pipe (N) by means of a P-trap; and a
waste disposal tank being connected with the main flow pipe by means of a
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valve mechanism; wherein the valve mechanism is configured to allow flow
from the main flow pipe (M) to the retention tank to the secondary flow pipe
(N) through the P-trap in the closed condition of the valve unit; and the valve
mechanism being configured to allow flow from the main flow pipe (M) to the
waste disposal tank by bypassing the P-trap in the open condition of the valve
unit.