Note: Descriptions are shown in the official language in which they were submitted.
CA 02877341 2015-01-09
VALVE MECHANISM FOR CONTROLLING RELEASE OF PRESSURIZED FLUID
FIELD OF INVENTION
[0001] The present invention relates to valve mechanisms, and more
particularly to valve
mechanisms for metering discharge of a fluid.
BACKGROUND OF THE INVENTION
[0002] Clogged drains can present an annoying and potentially serious problem.
Many
different types of material can form or be incorporated into a drain clog, and
different types of
chemical drain cleaners are known. Some of these chemical drain cleaners are
potentially
hazardous.
[0003] The use of pressurized gas to clear clogged drains is also known.
Typically, a user will
place the outlet of a gas-based drain clearing device against the mouth of the
drain to be
cleared, and apply pressure to an actuator, which causes a valve to be opened
so that the
pressurized gas flows into the drain to remove the clog. Typically, the valve
will stay open as
long as pressure continues to be applied to the actuator, which can result in
too much gas
being released into the drain, potentially damaging it. One solution to this
problem is to
provide a single-use cartridge containing a measured amount of gas, but this
approach requires
the cartridge (or the device, where the cartridge is integral thereto) to be
replaced each time
the drain clearing device is used. This can be particularly inconvenient for
stubborn drain
clogs which require more than one burst of gas to be removed.
[0004] In addition to drain clearing devices, there are other applications in
which metered
release of a pressurized fluid is desirable.
SUMMARY OF THE INVENTION
[0005] A valve mechanism for controlling release of pressurized fluid
comprises a housing
and a fluid chamber defined within the housing. The fluid chamber has a fluid
chamber inlet
and has a plunger aperture and defines an interior volume. The valve mechanism
further
comprises a plunger having a closed end and a plunger outlet end. The plunger
has at least
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one plunger fluid passage extending partially along a length of the plunger
from the plunger
outlet end, and the plunger has at least one plunger inlet defined in a
longitudinal wall thereof
in fluid communication with the plunger fluid passage(s). The plunger is
slidably received in
the plunger aperture in sealing engagement therewith, with the closed end
within the interior
volume of the fluid chamber, so as to be movable between a fluid retention
position in which
the plunger inlet(s) are isolated from the interior volume of the fluid
chamber and a fluid
release position in which the plunger inlet(s) are in fluid communication with
the interior
volume of the fluid chamber. A plunger biasing member acts between the plunger
and the
housing to bias the plunger into the fluid retention position. The valve
mechanism further
comprises a plunger driver having a driving end and a driver outlet end and
having at least one
driver fluid passage extending therethrough. The plunger driver is slidably
received within
the housing. A guide channel guides the driving end of the plunger driver into
engagement
with the plunger to cause the plunger and the plunger driver to move in unison
and move the
plunger into the fluid release position during a first portion of a stroke of
the plunger driver;
and further guides the plunger driver to permit the plunger to return to the
fluid retention
position under urging from the plunger biasing member during a second portion
of the stroke
of the driver towards the fluid chamber. At least when the plunger is in the
fluid release
position, the plunger fluid passage(s) are in fluid communication with the at
least one driver
fluid passage.
[0006] In one embodiment, following completion of the stroke of the driver
towards the fluid
chamber and release of external force acting on the driver, the plunger driver
returns to its pre-
stroke position when the valve mechanism is oriented with the plunger above
the plunger
driver. Preferably, the plunger driver returns to its pre-stroke position
under gravity.
[0007] In a particular embodiment, the at least one plunger fluid passage
comprises a single
plunger fluid passage and the plunger has a peripheral rim surrounding the
single plunger fluid
passage at the plunger outlet end. In this embodiment, the driving end of the
plunger driver
engages the peripheral rim at the plunger outlet end during the first portion
of the stroke of the
plunger driver towards the fluid chamber, and the driving end of the plunger
driver moves into
registration with the single plunger fluid passage so that the driving end of
the plunger driver
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is received within the single plunger fluid passage to permit sliding movement
of the plunger
toward the plunger driver during the second portion of the stroke of the
driver towards the
fluid chamber when the valve mechanism is oriented with the plunger actuator
above the
driver.
[0008] In one embodiment, the plunger driver comprises an actuator head
comprising a
plurality of fingers joined to a common base and separated from one another by
a cruciform
gap which allows the fingers to bend inwardly toward one another. The tips of
the fingers
form the driving end of the plunger driver and the driver fluid passage opens
into the
cruciform gap. In a preferred embodiment, a guide channel is defined in the
housing, and the
guide channel forces the fingers to bend inwardly during the second portion of
the stroke of
the plunger driver towards the fluid chamber until the outer width of the
driving end is smaller
than the width of the plunger fluid passage so that the driving end fits
within the plunger fluid
passage. In a particularly preferred embodiment, the actuator head is narrower
at the driving
end than at a driven end thereof and the outer surfaces of the fingers taper
inwardly from the
driven end toward the driving end.
[0009] A drain clearing device may comprise a valve mechanism as described
above, and a
fluid reservoir having a sufficient quantity of sufficiently pressurized gas
disposed therein,
with the fluid reservoir being in fluid communication with the fluid chamber
inlet. The fluid
reservoir may consist of a separate cartridge secured within a cartridge
cavity in a main body
of the drain clearing device.
[0010] An external actuator may be movably secured to the housing and
mechanically
coupled to the driver to cause sliding movement of the driver toward the fluid
chamber when
the external actuator moves towards the fluid chamber. The external actuator
may be an outlet
fitting for sealingly engaging a drain, with the outlet fitting being secured
to an outlet end of
the drain clearing device and having an outlet aperture in fluid communication
with the driver
fluid passage.
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[0011] The drain clearing device may further comprise a cartridge insertion
aperture at one
end of the main body, a cartridge piercer disposed at an opposite end of the
cartridge cavity
from the cartridge insertion aperture, and a cartridge cavity closure cap
removably securable
to the main body to obstruct the cartridge insertion aperture and push an
outlet end of the fluid
cartridge into engagement with the cartridge piercer and close the cartridge
cavity. The
cartridge cavity closure cap is constrained, during removal thereof from the
main body, to
move through an intermediate position in which the fluid cartridge is released
from
engagement with the cartridge piercer while the cartridge cavity closure cap
remains secured
to the main body and the cartridge cavity is vented to ambient.
[0012] In one embodiment, the cartridge insertion aperture is defined by a
hollow threaded
shaft portion having at least one vent defined therein in fluid communication
with the
cartridge cavity, the cartridge cavity closure cap is correspondingly threaded
for threaded
engagement with the threaded shaft portion, and removal of the cartridge
cavity closure cap
consists of unscrewing the cartridge cavity closure cap from the threaded
shaft portion of the
main body. In this embodiment, in the intermediate position the cartridge
cavity closure cap
has been unscrewed past the at least one vent to expose the at least one vent
while the
cartridge cavity closure cap remains threadedly secured to the main body.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] These and other features of the invention will become more apparent
from the
following description in which reference is made to the appended drawings
wherein:
Figure 1 is a perspective view of an exemplary drain clearing device according
to an aspect of
the present invention;
Figure 2 is an exploded view of the drain clearing device of Figure 1;
Figure 2A is a top perspective view of a plunger driver of the drain clearing
device of Figure
1;
Figure 2B is a side elevation view of the plunger driver of Figure 2A;
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Figure 2C is a top plan view of the plunger driver of Figure 2A;
Figure 2D is a bottom plan view of the plunger driver of Figure 2A;
Figure 2E is side cross-sectional view of the plunger driver of Figure 2A;
Figure 3 is a cross-sectional view of the drain clearing device of Figure 1,
showing overall
assembly thereof;
Figure 3A is a cross-sectional view of a portion of the drain clearing device
of Figure 1, prior
to commencement of a stroke of a driver thereof toward a fluid chamber
thereof;
Figure 3B is a cross-sectional view of a portion of the drain clearing device
of Figure 1,
during an initial stage of a first portion of the stroke of the driver thereof
toward the fluid
chamber thereof;
Figure 3C is a cross-sectional view of a portion of the drain clearing device
of Figure 1,
during a subsequent stage of a first portion of the stroke of the driver
thereof toward the fluid
chamber thereof;
Figure 3D is a cross-sectional view of a portion of the drain clearing device
of Figure 1,
during completion of a second portion of the stroke of the driver thereof
toward the fluid
chamber thereof;
Figure 4A is a cross-sectional view of an upper portion of the drain clearing
device of Figure
1, with a cartridge cavity closure cap secured to a main body of the drain
clearing device;
Figure 4B is a cross-sectional view of an upper portion of the drain clearing
device of Figure
1, with the cartridge cavity closure cap partially removed and still
threadedly secured to the
main body of the drain clearing device;
Figure 5A shows a first exemplary embodiment of a fluid cartridge;
Figure 5B shows a second exemplary embodiment of a fluid cartridge; and
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Figure 5C shows a third exemplary embodiment of a fluid cartridge.
DETAILED DESCRIPTION
[0014] Referring now to Figure 1, a drain clearing device according to an
aspect of the present
invention is shown generally at 10. The drain clearing device 10 has a
reservoir end 18 and an
outlet end 20, and the exterior of the drain clearing device 10 is defined by
a main body 12, a
cartridge cavity closure cap 14, an outlet end cap (not shown in Figure 1) and
an outlet fitting
16.
[0015] Turning now to Figure 2, the external and internal components of the
drain clearing
device 10 are shown in exploded view. Received within the main body 12 are a
cartridge
receiving member 22, a cartridge seal 24, a cartridge piercer 26, a fluid
chamber member 28, a
plunger biasing member 30 (a coil spring in the exemplary embodiment shown), a
plunger 32,
a fluid chamber seal 34, a guide collar 36, a plunger driver 37, a driver
receiver member 42
and a grommet 44, and the outlet end cap 46 retains the foregoing components
within the
main body 12. The main body 12, the cartridge receiving member 22, the fluid
chamber
member 28, the guide collar 36, driver receiver member 42 and outlet end cap
46 each form
part of an overall housing. As can be seen, the cartridge cavity closure cap
14 and the outlet
end cap 46 are threadedly received by the main body 12, and the outlet fitting
16 includes an
end piece 48.
[0016] With reference now to Figure 3, assembly of the various components is
shown. When
in use, a fluid cartridge 50 is removably received within a cartridge cavity
52 defined in the
main body 12 of the drain clearing device 10. The fluid cartridge 50 is thus a
reservoir of
fluid, which (as will be described in greater detail below) can be selectively
expelled from the
overall outlet 150 at the outlet end 20 of the drain clearing device 10 to
assist in clearing a
blockage in a drain. The fluid cartridge 50 is preferably a carbon dioxide
(CO2) cartridge of
conventional design, comprising a generally cylindrical metal canister 54 of
sufficient strength
and having a quantity of pressurized CO2 contained therein, and having a thin
metal seal 56 at
an outlet end thereof To install the fluid cartridge, a user would unscrew the
cartridge cavity
closure cap 14, slide the fluid cartridge 50 through the cartridge insertion
aperture 160 into the
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cartridge cavity 52 in the main body 12 of the drain clearing device 10, and
then thread the
_
cartridge cavity closure cap 14 back onto the main body 12. The cartridge
cavity closure cap
14 has a cradle 58 complementary to the spherical shape of the non-outlet end
60 of the fluid
cartridge 50 for engaging the non-outlet end 60 of the fluid cartridge 50. The
cartridge piercer
26 is disposed at the opposite end of the cartridge cavity 52 from the
cartridge insertion
aperture 160, and thus as the cartridge cavity closure cap 14 is tightened
onto the main body
12, the fluid cartridge 50 is forced toward the outlet end 20 of the drain
clearing device 10
until the seal 56 is pierced by the cartridge piercer 26, allowing the fluid
contained in the fluid
cartridge 50 to flow into the valve mechanism, which is described in greater
detail below in
respect of Figures 3A to 3D. As can be seen, the piercing cannula 62 of the
cartridge piercer
26 has a generally frusto-conical shape terminating in an angular plane to
define a piercing
edge. Without being limited by theory, it is believed that the generally
frusto-conical shape
the piercing cannula 62 facilitates sealing of the cartridge 50 against the
piercing cannula 62.
It has been found that a relatively short piercing cannula 62 is desirable, so
that it is the last
three-quarters of a revolution of the cartridge cavity closure cap 14 which
causes the seal 56 to
be pierced.
[0017] Once the quantity of fluid (preferably CO2) contained in a given fluid
cartridge 50 has
been exhausted, or the pressure in the fluid cartridge 50 has been reduced so
that it is
insufficient for its purpose (e.g. clearing a drain), the cartridge cavity
closure cap 14 can be
unscrewed from the main body 12, and the fluid cartridge 50 can be removed and
replaced
with a new fluid cartridge 50. Thus, a drain clearing device such as the
exemplary drain
clearing device 10 is reusable. In addition, depending on the particular
construction of the
fluid cartridges 50, the fluid cartridges 50 may optionally be refilled and
resealed for reuse, or
may be recycled.
[0018] For use in a drain clearing device, different sizes of fluid cartridges
50, containing
different amounts of fluid, may be advantageous. Three exemplary sizes of
fluid cartridges
containing different quantities of CO2 gas are illustrated in Figures 5A to
5C.
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,
[0019] Figure 5A shows first exemplary fluid cartridge 50A, which would
initially contain 25
_
grams of CO2 at a pressure of approximately 850 pounds per square inch
(approximately 60
- bar). The dimensions of the first exemplary fluid cartridge 50A are
as follows:
Dimension Measurement (millimeters)
Cl 12.0
El 10.5
Fl 3.0
G1 2.4
H1 12.5
J1 16.5
Li 109.0
R1 (radius) 5.0
W1 25.4
[0020] Figure 5B shows second exemplary fluid cartridge, which would initially
contain 33
grams of CO2 at a pressure of approximately 850 pounds per square inch
(approximately 60
bar). The dimensions of the second exemplary fluid cartridge are as follows:
Dimension Measurement (millimeters)
C2 12.0
E2 10.5
F2 3.0
G2 2.4
H2 12.5
J2 16.5
L2 142.0
R2 (radius) 5.0
W2 25.4
[0021] Figure 5C shows third exemplary fluid cartridge, which would contain 45
grams of
CO2 at a pressure of approximately 850 pounds per square inch (approximately
60 bar). The
dimensions of the third exemplary fluid cartridge are as follows:
Dimension Measurement (millimeters)
C3 12.0
E3 10.5
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F3 3.0
G3 2.4
H3 12.5
J3 16.5
L3 142.0
R3 (radius) 5.0
W3 30.0
[0022] Depending on the exemplary fluid cartridge to be used, the dimensions
of the cartridge
cavity 52, cartridge cavity closure cap 14 other components of the drain
clearing device 10
would be adapted accordingly.
[0023] Referring now to Figures 3A to 3D, a valve mechanism forming part of a
drain
clearing device according to an aspect of the present invention is indicated
generally by the
reference numeral 80. The valve mechanism 80 comprises a housing which, as
described
above, includes the cartridge receiving member 22, the fluid chamber member
28, the guide
collar 36 and the driver receiver member 42, as well as the cartridge piercer
26 and the fluid
chamber seal 34. The valve mechanism 80 further comprises the plunger biasing
member 30,
the plunger 32 and the plunger driver 37.
[0024] A fluid chamber 82 is defined within the housing, and in the
illustrated embodiment is
defined by the hollow interior volume of the fluid chamber member 28. A fluid
chamber inlet
84 into the fluid chamber 82 is defined at the inlet end 28A of the fluid
chamber member 28
by a passageway 84 in the piercing cannula 62 of the cartridge piercer 26, so
that the interior
volume of the fluid chamber 82 is in fluid communication with the interior of
the fluid
cartridge 50 when the same is installed. In the illustrated embodiment, the
cartridge piercer
26 is friction fit into a receiving collar 86 at the inlet end 22A of the
cartridge receiving
member 22, and is supported by the annular edge of the input end 28A of the
fluid chamber
member 28. The cartridge seal 24 is friction fit into the receiving collar 86
on top of the
cartridge piercer 26 to surround the piercing carmula 62. Other suitable
arrangements for
installing the cartridge piercer 26 and cartridge seal 24 may also be used,
without departing
from the scope of the present invention.
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[0025] An opening 90 at the outlet end 28B of the fluid chamber member 28
cooperates with
the fluid chamber seal 34 to define a plunger aperture 88 in the fluid chamber
82. The plunger
32 is slidably received in the plunger aperture 88 in sealing engagement
therewith, as will be
described in greater detail below.
[0026] The plunger 32 has a closed end 32A and a plunger outlet end 32B. A
plunger fluid
passage 92 extends partially along a length of the plunger 32 from the plunger
outlet end 32B.
A peripheral rim 94 surrounds the plunger fluid passage 92 at the plunger
outlet end 32B. The
plunger has two diametrically opposed plunger inlets 96 defined in a
longitudinal wall 98
thereof in fluid communication with the plunger fluid passage 92. In alternate
embodiments,
the plunger 32 may have only one plunger inlet, or may have more than two
plunger inlets.
[0027] As noted above, the plunger 32 is slidably received in the plunger
aperture 88.
Frictional engagement of an inner annular surface of the fluid chamber seal 34
with the
exterior of the longitudinal wall 98 of the plunger 32 inhibits the undesired
escape of fluid
from the fluid chamber 82, so that the plunger 32 is in sealing engagement
with the plunger
aperture 88. The closed end 32A of the plunger 32 is disposed within the
interior volume of
the fluid chamber 82, and the plunger 32 is movable between a fluid retention
position (shown
in Figure 3A) in which the plunger inlets 96 are isolated from the interior
volume of the fluid
chamber 82, and a fluid release position (shown in Figure 3C) in which the
plunger inlets 96
are in fluid communication with the interior volume of the fluid chamber 82.
The plunger 32
has an annular stop 100 which cooperates with an annular shoulder 102 inside
the fluid
chamber member 28 and with the fluid chamber seal 34 and the guide collar 36
to limit the
axial range of motion of the plunger 32 and thereby define the fluid retention
position and
fluid release position. The annular stop 100 also serves as an engagement
surface for the
plunger biasing member 30.
[0028] As shown in Figure 3A, the plunger biasing member 30 acts between the
plunger 32,
specifically the annular stop 100, and the housing, in particular the annular
rim of the cartridge
piercer 26, to urge the plunger into the fluid retention position in which the
annular stop 100
abuts the fluid chamber seal 34. When the plunger 32 is in the fluid retention
position, the
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plunger inlets 96 are outside of the fluid chamber 82 and are therefore
isolated therefrom.
Conversely, when the plunger 32 is in the fluid release position, as shown in
Figure 3C, the
plunger inlets 96 are inside the fluid chamber 82 and therefore are in fluid
communication
with the interior volume of the fluid chamber 82.
[0029] As noted above, the valve mechanism 80 further includes the plunger
driver 37.
Referring now to Figures 2A to 2E, the plunger driver 37 is shown in more
detail. The
exemplary plunger driver 37 comprises an actuator head 38 and a driver shaft
40. The
exemplary plunger driver 37 is formed from a fairly rigid, resilient material
and is of
monolithic construction; in other embodiments the actuator head and driver
shaft may be
separate parts that are rigidly secured together to form the plunger driver;
in such
embodiments only the actuator head need be resilient. The actuator head 38 has
a driving end
38A which drives the plunger 32, and a driven end 38B coupled to the driver
shaft 40 so that
movement of the driver shaft 40 drives movement of the actuator head 38. In
the illustrated
embodiment, the actuator head 38 comprises four fingers 108 joined to a common
base 106
and separated from one another by a cruciform gap 104 centered on and
extending
longitudinally along the axis of the plunger driver 37 from the driving end
38A to the base
106. The cruciform gap 104 allows the fingers 108 to bend inwardly toward one
another.
While the exemplary actuator head 38 comprises four fingers, in other
embodiments more
than four or fewer than four fingers may be used. As used herein, the telin
"cruciform" is not
limited in meaning to a four-armed cross and may refer to a cross having any
number of arms.
For example, where the actuator head comprises three arms, the gap would be a
three-armed
(triskelion) cruciform gap and where the actuator head comprises five arms,
the gap would be
a five-armed cruciform gap. The tips 114 of the fingers 108 form the driving
end 38A of the
actuator head 38. The actuator head 38 is narrower at the driving end 38A than
at the driven
end 38B, and the outer surfaces 109 of the fingers 108 taper inwardly from the
driven end 38B
toward the driving end 38A of the actuator head 38. Preferably, the outer
width of the driving
end 38A, when the fingers 108 are not bent inwardly toward one another, is
approximately
equal to or slightly smaller than the outer width of the peripheral rim 94 of
the plunger 32.
The cruciform gap 104 is of sufficient size, and the actuator head 38 is
sufficiently resilient, so
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that the fingers 108 can bend inwardly toward one another by a sufficient
amount to make the
outer width of the driving end 38A smaller than the width of the plunger fluid
passage 92 at
the plunger outlet end 32B so that the driving end 38A can fit within the
plunger fluid passage
92 when the fingers 108 are bent inwardly, as explained further below.
[0030] In the illustrated embodiment the actuator head 38 is received in an
interior space 103
defined within the guide collar 36 and the driver receiver member 42, with the
driving end
38A facing toward the plunger 32. The driver shaft 40 is slidingly received
within a central
aperture 110 (Figure 2) in the driver receiver member 42. The driver shaft 40
has an actuator
driving end 40A coupled to the driven end 38B of the actuator head 38 and a
driver outlet end
40B, and a driver fluid passage 112 extends through the driver 40 from the
driver outlet end
40B through the actuator driving end 40A and the common base 106 and opens
into the
cruciform gap 104 between the fingers 108.
[0031] A guide channel 120 is defined within the housing. The guide channel
120 is defined
primarily within the guide collar 36, which also includes the plunger bore 122
which slidingly
receives the plunger outlet end 32B. The guide channel extends partially into
the driver
receiver member 42. In the illustrated embodiment, the guide channel 120 has a
narrow end
adjacent the plunger bore 122 and a wide end within the driver receiver
member, and the
guide channel 120 is coaxial with the plunger bore 122 and tapers between the
wide end and
the narrow end. In other embodiments, a single bore of uniform width may form
both the
plunger bore and the guide channel; in still other embodiments the plunger
bore and guide
channel may be of discontinuous width.
[0032] As the plunger driver 37 moves into the second portion of its stroke
towards the fluid
chamber 82, the outer surfaces 109 of the fingers 108 will engage the surface
of the guide
channel 120, forcing the fingers 108 to bend inwardly as the plunger driver 37
continues its
stroke. Eventually, the fingers 108 are bent far enough inwardly that the
outer width of the
driving end 38A is smaller than the width of the plunger fluid passage 92 at
the plunger outlet
end 32B, enabling the driving end 38A to fit within the plunger fluid passage
92. Thus, the
shape of the guide channel 120 and the shape of the actuator head 38 are
interrelated and the
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guide channel 120 and the actuator head 38, in particular the fingers 108
thereof, are shaped to
cooperate with one another to achieve the desired inward bending of the
fingers 108 as the
actuator head 38 moves along the guide channel 120 towards the fluid chamber
82.
[0033] The drain clearing device 10 includes an external actuator. In the
illustrated
embodiment, the external actuator is the outlet fitting 16, including the end
piece 48, which is
preferably made from a resilient material to assist in sealing against a
drain, such as exemplary
drain 152. As can be seen in Figures 3A to 3D, the end piece 48 has a
truncated dome shape,
which, because the end piece 48 is resilient, enables the outlet fitting 16
(including the end
piece 48) to sealingly engage a drain, such as the exemplary drain 152.
[0034] The outlet fitting 16 has a generally cylindrical outer surface, and
has a plurality of
circumferentially spaced, inwardly projecting radial ribs 124 which strengthen
the outlet
fitting 16 and assist in centering it about the main body 12 when installed.
The outlet end 16B
of the outlet fitting 16 has a cylindrical recess 126 which receives a
correspondingly sized
outer cylindrical wall 128 on the end piece 48 in a friction fit, so as to
secure the end piece 48
to the outlet fitting 16. A plurality of radially spaced, generally sector-
shaped spokes 130 are
defined in the floor of the cylindrical recess 126, and provide additional
support for the ribs
124.
[0035] Concentrically spaced inner and outer cylindrical mounting walls 132,
134 on the
outlet fitting 16 project toward the inlet end 16A thereof, and define an
annular mounting
recess 136 therebetween. The annular mounting recess 136 receives the hollow
cylindrical
mounting end 138 of the resilient grommet 44 in a friction fit, thereby
movably securing the
outlet fitting 16 to the housing of the drain clearing device 10.
[0036] An annular driver engagement shoulder 140 is defined in the inner
surface 142 of the
inner cylindrical mounting wall 132, which engages the driver outlet end 40B
of the driver
shaft 40. To this end, the driver outlet end 40B has a slightly smaller
diameter than the rest of
the driver shaft 40. This engagement between the annular driver engagement
shoulder 140
and the driver outlet end 40B mechanically couples the outlet fitting 16 to
the plunger driver
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37, so that when the outlet fitting 16 moves toward the fluid chamber 82, it
will cause axial,
sliding movement of the driver shaft 40 within the driver receiver member 42
and hence
movement of the actuator head 38. The inner surface 142 of the inner
cylindrical mounting
wall 132 is sloped so that it is wider toward the inlet end 16A of the outlet
fitting 16 and
narrower toward the outlet end 16B of the outlet fitting 16, which assists in
guiding the driver
outlet end 40B of the driver shaft 40 into engagement with the annular driver
engagement
shoulder 140 during installation of the outlet fitting 16.
[0037] An outlet fitting fluid passage 144 is defined in the floor of the
cylindrical recess 126
and, when the driver outlet end 40B engages the annular driver engagement
shoulder 140, the
outlet fitting fluid passage 144 is in fluid communication with the driver
fluid passage 112.
When the end piece 48 is installed on the outlet fitting 16, the outlet
fitting fluid passage 144
opens into a first cylindrical fluid passage 146 in the end piece 48, which in
turn opens into a
second, wider cylindrical fluid passage 148 in the end piece 48, which defines
an overall
outlet aperture 150 for the drain clearing device 10.
[0038] Operation of an exemplary drain clearing device 10 according to an
aspect of the
present invention will now be described with respect to Figures 3A to 3D.
Generally
speaking, to use the exemplary drain clearing device 10, a user would position
it so that the
outlet end 16B of the outlet fitting 16 seals the drain to be cleared, and
then apply downward
pressure, for example by grasping the main body 12 and pushing it towards the
drain 152,
thereby also pushing the main body 12 into the outlet fitting 16.
[0039] In Figure 3A, the drain clearing device has been placed against an
exemplary drain
152, so that the outlet fitting 16, and more particularly the resilient end
piece 48, is positioned
to seal the mouth of the drain 152. No pressure has yet been applied. When
clearing a drain
with a drain clearing device such as drain clearing device 10, the water level
in the sink whose
drain is to be cleared should generally be high enough to at least cover the
end piece 48
(typically about one inch of water). In addition, where the obstructed drain
is part of a double
sink, the second drain aperture (i.e. the drain aperture with which the drain
clearing device is
not being used) should be temporarily obstructed to avoid undesirable
backflow.
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[0040] Reference is now made to Figure 3B, which shows an initial stage of the
first portion
of the stroke of the plunger driver 37 towards the fluid chamber 82. As a user
applies
downward pressure (indicated by the arrow "D") to the main body 12, the main
body will
move downward relative to the outlet fitting 16, which is braced against the
exemplary drain
152. This downward movement of the main body 12 relative to the outlet fitting
16
compresses the resilient grommet 44. Viewed another way, the outlet fitting 16
moves
upward relative to the main body 12.
[0041] Because the annular driver engagement shoulder 140 inside the outlet
fitting 16
engages the driver outlet end 40B of the plunger driver 37, the outlet fitting
16 is mechanically
coupled thereto, and the relative movement of the outlet fitting 16 toward the
main body 12
(and hence toward the fluid chamber 82) causes a corresponding sliding
movement of the
driver shaft 40 within the driver receiver member 42, also toward the fluid
chamber 82. In
turn, because the actuator head 38 is coupled to the driver shaft 40, the
movement of the
driver shaft 40 toward the fluid chamber 82 causes the actuator head 38 to
move toward the
fluid chamber 82, and hence toward the plunger 32.
[0042] As the plunger driver 37 continues to move through the first portion of
its stroke and,
the driving end 38A (formed by the tips of the fingers 108) engages the
peripheral rim 94 at
the plunger outlet end 32A. The engagement of the driving end 38A of the
actuator head 38
with the peripheral rim 94 results in motion of the plunger driver 37, during
the remainder of
the first portion of its stroke toward the fluid chamber 82, causing the
plunger driver 37 and
the plunger 32 to move in unison toward the fluid chamber 82. During this
subsequent stage
of the first portion of the stroke of the plunger driver 37 towards the fluid
chamber 82, even
though the plunger 32 is moving into the fluid chamber 82, the pressurized
fluid remains
substantially trapped in the fluid chamber 82 by the fluid chamber seal 34.
[0043] Turning now to Figure 3C, which shows the final stage of the first
portion of the stroke
of the plunger driver 37 toward the fluid chamber 82, the plunger driver 37
has pushed the
plunger 32 into the fluid release position, with the plunger inlets 96 in
fluid communication
with the interior volume of the fluid chamber 82. As can be seen in Figure 3C,
with the
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CA 02877341 2015-01-09
plunger 32 in the fluid release position, the plunger fluid passage 92 is in
fluid communication
with interior space 103 defined within the guide collar 36 and the driver
receiver member 42
= and hence, via the cruciform gap 104, in fluid communication with the
driver fluid passage
112. As a result, pressurized fluid in the fluid chamber 82 is able to escape
therefrom by
passing through the plunger inlets 96 into the plunger fluid passage 92, from
the plunger fluid
passage 92 into the cruciform gap 104, from the cruciform gap 104 into the
driver fluid
passage 112, and then from the driver fluid passage 112 into the outlet
fitting fluid passage
144, and finally through the first and second fluid passages 146, 148 in the
end piece 48a and
hence through the outlet aperture 150 and into the drain 152, as indicated by
the arrows
showing the fluid flow path. Thus, the fluid, so long as it is sufficiently
pressurized, will
assist in clearing a blockage downstream of the drain. Pressure within the
fluid chamber 82 is
maintained by inflow of pressurized fluid from the fluid cartridge 50 by way
of the fluid
chamber inlet 84.
[0044] As can also be seen in Figure 3C, as the plunger driver 37 completes
the first portion
of its stroke toward the fluid chamber 82, the outer surfaces 109 of the
fingers 108 engage the
surface of the guide channel 120 and begin forcing the fingers 108 to bend
inwardly toward
one another. However, at this stage of the stroke the fingers 108 are not bent
inwardly by a
sufficient amount to cause the outer width of the driving end 38A to become
smaller than the
width of the plunger fluid passage 92 at the plunger outlet end 32B.
[0045] A valve mechanism 80 according to an aspect of the present invention
provides for
mechanical timing and metering of the amount of fluid released, because the
plunger 32 is
returned from the fluid release position to the fluid retention position as
the stroke of the
driver 40 toward the fluid chamber is completed.
[0046] With reference now to Figure 3D, as the plunger driver 37 continues
into the second
portion of its stroke toward the fluid chamber 82, the outer surfaces 109 of
the fingers 108
continue to engage the surface of the guide channel 120 and continue to force
the fingers 108
to bend inwardly as the driving end 38A continues to move along the guide
channel 120.
When the driving end 38A has moved far enough into the guide channel 120 that
that the
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CA 02877341 2015-01-09
outer width of the driving end 38A is smaller than the width of the plunger
fluid passage 92 at
the plunger outlet end 32B, the driving end 38A disengages from the peripheral
rim 94 and
slides into the plunger fluid passage 92. This permits sliding movement of the
plunger 32
back toward the driver outlet end 40B of the plunger driver 37, since such
movement is no
longer obstructed by engagement of the driving end 38A with the peripheral rim
94 at the
plunger outlet end 32B. Thus, as the plunger driver 37 completes the second
portion of its
stroke toward the fluid chamber 82, the plunger biasing member 30 urges the
plunger 32 away
from the fluid chamber 82, with the driver end 38A received within and sliding
along the
plunger fluid passage 92 as the plunger 32 moves. In other words, the plunger
32 can slide
along the outer surface 109 of the driving end 38A of the actuator head 38
under urging from
the plunger biasing member 30. The plunger 32 thus returns to the fluid
retention position,
with the plunger inlets 96 outside of, and hence isolated from, the fluid
chamber 82.
Pressurized fluid in the fluid chamber 82 is once again trapped therein by
cooperation of the
annular stop 100 on the plunger and the fluid chamber seal 34.
[0047] The exemplary valve mechanism 80 described herein provides for a timed
and
metered fluid release, because a single stroke of the plunger driver 37
towards the fluid
chamber 82 will release a limited, measured, quantity of fluid, no matter how
long the plunger
driver 37 is maintained in position at the completion of its stroke. More
particularly,
continuing to push the plunger driver 37 toward the fluid chamber 82 does not
release any
additional fluid, because fluid is released only during the first portion of
the stroke, and the
plunger 32 has returned to the fluid retention position by the time the stroke
is completed.
Thus, continuing to push the main body 12 toward the outlet fitting 16 will
not release more
fluid than the metered amount.
[0048] The amount of fluid released is limited by the size of the plunger
inlets 96, and by the
parameters of the plunger 32 and plunger driver 37, which determine how long
the plunger
will remain in the fluid release position during a given stroke of the driver
shaft 40 toward the
fluid chamber 82. Where a valve mechanism according to the present invention
is to be used
in a drain clearing device, as herein shown and described, the cartridge
pressure and other
parameters should be selected so that the amount of fluid discharged on a
single stroke is
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CA 02877341 2015-01-09
sufficient to clear at least a typical drain blockage from a typical drain,
but not so much as to
damage the drain. While the speed of the stroke will affect this duration
somewhat (i.e. a
slower stroke may release slightly more fluid than a longer stroke), as long
as sufficient force
=
is applied to the driver these variations are unlikely to be significant. For
example, where a
valve mechanism according to an aspect of the present invention is used in a
drain clearing
device as illustrated, any variations resulting from differences in the
speed/force with which a
user pushes the main body 12 toward the outlet fitting 16 while the outlet
fitting 16 engages a
drain 152 are unlikely to adversely affect operation of the device. Because
the fluid output is
metered, multiple fluid discharges from a single fluid cartridge 50 are
possible.
[0049] Following completion of the stroke of the driver 40 towards the fluid
chamber 82, as
shown in Figure 3D, upon release of downward pressure on the main body 12, the
resilient
grommet 44 will push the outlet fitting 16 away from the main body 12 and
return the main
body 12 and the outlet fitting 16 to their original relative positions. This
releases the external
force acting on the plunger driver 37 (by way of the annular driver engagement
shoulder 140
in the outlet fitting 16) and the plunger driver 37 will return to its pre-
stroke position under
gravity and the resilient fingers 108 will return to their unbent positions
(Figure 3A) when the
valve mechanism 80 is oriented with the plunger 32 above the plunger driver
37. The valve
mechanism 80 is now ready for a new stroke of the driver 40 toward the fluid
chamber 82.
[0050] Reference is now made to Figures 4A and 4B. As noted above, in the
exemplary
embodiment a fluid cartridge 50 is received within a cartridge cavity 52
defined in the main
body 12 of the drain clearing device 10. More particularly, the main body 12
defines a
cartridge insertion aperture 160 at one end of the main body 12, namely the
reservoir end 18
of the drain clearing device 10. As was explained above, the cartridge piercer
26 (not shown
in Figures 4A and 4B) is located at the opposite end of the cartridge cavity
52 from the
cartridge insertion aperture 160, so that as the cartridge cavity closure cap
14 is secured to the
main body 12, it will obstruct the cartridge insertion aperture 16 and push
the thin metal seal
56 at the outlet end of the fluid cartridge 50 into engagement with the
cartridge piercer 26. At
the same time, securing the cartridge cavity closure cap 14 to the main body
12 will close the
cartridge cavity 52. In this context, the term "close" denotes a seal which,
while not
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CA 02877341 2015-01-09
necessarily a perfect hermetic seal, generally maintains the pressure in the
cartridge cavity 52
and permits only very small amounts of fluid to escape over a prolonged
period. Figure 4A
shows the cartridge cavity closure cap fully secured to the main body 12.
=
[0051] An inspection aperture 162 is defined through the cradle 58 of the
cartridge cavity
closure cap 14, to assist a user in determining visually whether or not a
fluid cartridge is
contained within the cartridge cavity 52. Where no cartridge is contained in
the cartridge
cavity 52, the inspection aperture 162 will be dark, and where a fluid
cartridge 50 is contained
within the cartridge cavity 52, the bottom or non-outlet end 60 of the fluid
cartridge 50 will be
visible through the inspection aperture 162. To enhance visibility, the non-
outlet end 60 of
the fluid cartridge 50 can be painted with a color that contrasts with the
color of the outside of
the cradle 58 of the cartridge cavity closure cap 14. Because drain blockages
are infrequent,
the inspection aperture is advantageous, since it allows a user to check
whether a cartridge is
already loaded in the cartridge cavity 52 before removing the cartridge cavity
closure cap 14,
since removing the cap would allow a still-charged cartridge to vent to the
atmosphere,
wasting the remaining fluid therein. When the cartridge cavity closure cap 14
is fully secured
to the main body 12, the non-outlet end 60 of the fluid cartridge 50 seats
against the
correspondingly shaped cradle 50 on the cartridge cavity closure cap 14,
effectively sealing
the inspection aperture 162.
[0052] The cartridge cavity closure cap 14 is constrained, during removal
thereof from the
main body 12, to move through an intermediate position, as shown in Figure 4B.
In the
intermediate position, the fluid cartridge 50 is released from engagement with
the cartridge
piercer 26 while the cartridge cavity closure cap 14 remains secured to the
main body 12, and
the cartridge cavity 52 is vented to the ambient atmosphere. As can be seen in
Figure 4B, the
cartridge cavity closure cap 14 has been partially unscrewed from the main
body 12, and the
fluid cartridge 50 has, as a result of expulsion of some of the pressurized
fluid contained
therein, pushed upward away from the cartridge piercer 26, so that the non-
outlet end 60 of
the fluid cartridge 50 continues to seat against the correspondingly shaped
cradle 58 on the
cartridge cavity closure cap 14 and effectively seal the inspection aperture
162.
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CA 02877341 2015-01-09
[0053] In the illustrated embodiment, the cartridge insertion aperture 160 is
defined by a
hollow threaded shaft portion 164, which has a threaded outer surface 166, and
the cartridge
cavity closure cap has a correspondingly threaded inner surface 168 (best seen
in Figure 4B)
for threaded engagement with the threaded shaft portion 164. A vent 170 is
defined in the
threaded shaft portion 164 in fluid communication with the cartridge cavity
52.
[0054] Removal of the cartridge cavity closure cap 14 consists of unscrewing
the cartridge
cavity closure cap 14 from the threaded shaft portion 164 of the main body 12.
As a user
unscrews the cartridge cavity closure cap 14, it will reach a partially
unscrewed position (i.e.
between being fully tightened (Figure 4A) and being fully unscrewed and
removed from the
threaded shaft portion 164 (not shown)). In the partially unscrewed position,
the cartridge
cavity closure cap 14 has been unscrewed past the vent 170 while remaining
threadedly
secured to the threaded shaft portion 164 of the main body 12. Because the
vent 170 has been
exposed to the ambient atmosphere, pressurized fluid can escape from the fluid
cartridge 50
into the cartridge cavity 52 and then into the atmosphere via the vent 170,
while the fluid
cartridge 50 remains safely trapped in the cartridge cavity 52 by the
cartridge cavity end cap
14. In the absence of the vent 170, if a user were to unscrew the cartridge
cavity end cap 14
while the cartridge cavity 52 still contained a fluid cartridge 50 with a
significant volume of
pressurized fluid, the fluid cartridge 50 could be violently propelled out of
the cartridge cavity
52 at the moment the cartridge cavity end cap 14 was completely unscrewed,
posing a serious
risk to life and safety. In the process, the fluid cartridge 50 might also
impart a substantial
velocity to the cartridge cavity end cap 14, creating further danger.
Inclusion of the vent 170
substantially obviates this risk.
[0055] The above described system for venting a cartridge cavity prior to
complete removal of
the cartridge cavity closure cap is not limited to drain clearing devices, but
may be
incorporated into any cartridge-based device for controlled release of
pressurized fluid having
a similar construction. Generally speaking, devices where the above-described
venting system
is useful will include a main body defining a cartridge cavity and a cartridge
insertion aperture
at one end thereof, a cartridge piercer disposed at an opposite end of the
cartridge cavity from
the cartridge insertion aperture, an outlet, a valve mechanism including an
inlet connectable in
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CA 02877341 2015-01-09
fluid communication with a cartridge received in the cartridge cavity and
connected in fluid
communication with the outlet for selectively permitting gas from the
cartridge to be expelled
from the outlet, and a cartridge cavity closure cap removably securable to the
main body to
obstruct the cartridge insertion aperture and push an outlet end of the fluid
cartridge into
engagement with the cartridge piercer and close the cartridge cavity. When the
aforementioned venting system is incorporated into such a device, the
cartridge cavity closure
cap of the device will be constrained, during removal thereof from the main
body, to move
through an intermediate position in which the fluid cartridge is released from
engagement
with the cartridge piercer while the cartridge cavity closure cap remains
secured to the main
body and the cartridge cavity is vented to the ambient environment.
[0056] Components of a drain clearing device according to aspects of the
present invention
may be made from suitable types of metal or plastic. Fluid cartridges 50 are
preferably made
from metal. Components such as the cartridge receiving member 22, fluid
chamber member
28, guide collar 36 and driver receiver member 42 may be made from plastic and
designed to
snap-fit together, or may be maintained in their respective positions within
the main body 12
by shoulders within the main body 12 and on the outlet end cap 46
corresponding to
respective shoulders on the cartridge receiving member 22 and the driver
receiver member 42.
For example, with reference to Figure 3, in the illustrated embodiment the
cartridge receiving
member 22 has inner and outer annular shoulders 180, 182, respectively, which
engage
corresponding inner and outer annular shoulders 186, 184 on the main body 12,
and the outlet
end cap 46 similarly has an annular shoulder 188 which mates with an annular
shoulder 190
on the driver receiver member 42. The main body 12 may be formed from two
plastic halves,
which may be ultrasonically welded together. The plunger driver 37 is
preferably made from a
plastic material having sufficient rigidity to drive the plunger 32 while
retaining sufficient
resiliency to enable the required bending of the fingers 108. Suitably durable
metal is
preferred as the material for the cartridge piercer 26.
[0057] It will be appreciated that valve mechanisms according to aspects of
the present
invention, such as exemplary valve mechanism 80, are not limited to use in
drain clearing
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CA 02877341 2015-01-09
devices, and may be used in other devices where such mechanical fluid metering
would be
advantageous.
[0058] Moreover, while embodiments of a drain clearing device according to an
aspect of the
present invention have been described as receiving removable and replaceable
fluid cartridges,
it is within the contemplation of the inventor that alternate embodiments may
comprise a
disposable unit with an integral, pre-filled fluid reservoir.
[0059] Furthermore, while the exemplary plunger 32 and plunger driver 37 have
been shown
as having generally cylindrical features and as being generally symmetrical,
other suitable
shapes, both symmetrical and asymmetrical, may also be used so long as they do
not inhibit
the function of the mechanism. For example, and without limitation, the driver
shaft may
have a triangular, rectangular or hexagonal perimeter, and parts of the
plunger may be
similarly configured. In respect of the plunger, sharp corners should be
avoided on portions of
the exterior surface that will engage the fluid chamber seal, as such corners
typically adversely
affect sealing.
[0060] In addition, while the plunger 32 and plunger driver 37 have been shown
with
individual respective fluid passages 92 and 112, one or both of these
components may, with
suitable modifications, be provided with more than one fluid passage.
[0061] One or more currently preferred embodiments have been described by way
of example.
It will be apparent to persons skilled in the art that a number of variations
and modifications
can be made without departing from the scope of the invention as defined in
the claims.
[0062] The table below sets out a listing of the reference numerals used
herein, as well as the
part or feature identified by that reference numeral, for ease of reference.
No limitation is
implied by this table.
Reference Part/Feature Description
10 Drain clearing device (overall)
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CA 02877341 2015-01-09
12 Main body of drain clearing device
14 Cartridge cavity closure cap
16 Outlet fitting
16A Inlet end of outlet fitting
16B Outlet end of outlet fitting
18 Reservoir end of drain clearing device
20 Outlet end of drain clearing device
22 Cartridge receiving member
22A Inlet end of cartridge receiving member
24 Cartridge seal
26 Cartridge piercer
28 Fluid chamber member
28A Inlet end of fluid chamber member
28B Outlet end of fluid chamber member
30 Plunger biasing member
32 Plunger
32A Closed end of plunger
32B Plunger outlet end
34 Fluid chamber seal
36 Guide collar
37 Plunger driver
38 Actuator head of plunger driver
38A Driving end of actuator head
38B Driven end of actuator head
40 Driver shaft of plunger driver
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40A Actuator driving end of driver shaft
40B Driver outlet end
42 Driver receiver member
44 Grommet
46 Outlet end cap
48 End piece for outlet fitting
50 Fluid cartridge
50A First exemplary fluid cartridge
50B Second exemplary fluid cartridge
50C Third exemplary fluid cartridge
52 Cartridge cavity in main body
54 Generally cylindrical metal canister
56 Thin metal seal on generally cylindrical metal canister
58 Cradle in cartridge cavity closure cap
60 Non-outlet end of fluid cartridge
62 Piercing cannula
80 Valve mechanism generally
82 Fluid chamber
84 Fluid chamber inlet / passageway in cartridge piercer
86 Receiving collar at inlet end of cartridge receiving member
88 Plunger aperture in fluid chamber
90 Opening at outlet end of fluid chamber member
92 Plunger fluid passage
94 Peripheral rim surrounding plunger fluid passage
96 Plunger inlets
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CA 02877341 2015-01-09
98 Longitudinal wall of plunger
100 Annular stop on plunger
102 Annular shoulder inside fluid chamber member
103 Interior space defined within guide collar and driver receiver member
104 Cruciform gap between fingers of actuator head
106 Common base of actuator head
108 Fingers of actuator head
109 Outer surfaces of fingers
110 Central aperture in driver receiver member
112 Driver fluid passage
114 Tips of fingers
120 Guide channel
122 Plunger bore in guide collar
124 Inwardly projecting radial ribs on outlet fitting
126 Cylindrical recess in outlet end of outlet fitting
128 Outer cylindrical wall on end piece
130 Sector-shaped spokes defined in floor of cylindrical recess in outlet
fitting
132 Inner cylindrical mounting wall on outlet fitting
134 Outer cylindrical mounting wall on outlet fitting
136 Annular mounting recess between inner and outer cylindrical mounting
walls
138 Cylindrical mounting end of grommet
140 Annular driver engagement shoulder defined in inner surface of inner
cylindrical mounting wall on outlet fitting
142 Inner surface of inner cylindrical mounting wall on outlet fitting
144 Outlet fitting fluid passage
146 First cylindrical fluid passage in end piece
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CA 02877341 2015-01-09
148 Second cylindrical fluid passage in end piece
150 Overall outlet aperture
152 Exemplary drain
160 Cartridge insertion aperture in main body
162 Inspection aperture
164 Hollow threaded shaft portion defining cartridge insertion aperture
166 Threaded outer surface of threaded shaft portion
168 Threaded inner surface of cartridge cavity closure cap
170 Vent in threaded shaft portion
180 Inner annular shoulder on cartridge receiving member
182 Outer annular shoulder on cartridge receiving member
184 Outer annular shoulder on main body
186 Inner annular shoulder on main body
188 Annular shoulder on outlet end cap
190 Annular shoulder on driver receiver member
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