U.S. patent application number 09/862180 was filed with the patent office on 2001-12-27 for filter cartridge for water treatment device.
This patent application is currently assigned to Recovery Engineering, Inc.. Invention is credited to Hembree, Richard D..
Application Number | 20010054583 09/862180 |
Document ID | / |
Family ID | 23148774 |
Filed Date | 2001-12-27 |
United States Patent
Application |
20010054583 |
Kind Code |
A1 |
Hembree, Richard D. |
December 27, 2001 |
Filter cartridge for water treatment device
Abstract
A water filter cartridge including an outer shell, an inlet
opening proximate a first end, an outlet opening and a cam
extending axially from the first end. Cam is constructed and
arranged so as to reset a mechanical flow totalization mechanism in
a water treatment device. A channel and notch in the first end of
the cartridge provide fluid communication to a chamber of a water
treatment device.
Inventors: |
Hembree, Richard D.; (Edina,
MN) |
Correspondence
Address: |
MERCHANT & GOULD P.C.
Attn: Gregory A. Sebald
P.O. Box 2903
Minneapolis
MN
55402-0903
US
|
Assignee: |
Recovery Engineering, Inc.
Minneapolis
MN
|
Family ID: |
23148774 |
Appl. No.: |
09/862180 |
Filed: |
May 21, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09862180 |
May 21, 2001 |
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08629193 |
Apr 8, 1996 |
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6241103 |
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08629193 |
Apr 8, 1996 |
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08298044 |
Aug 30, 1994 |
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5525214 |
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08298044 |
Aug 30, 1994 |
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08207380 |
Mar 8, 1994 |
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5527451 |
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Current U.S.
Class: |
210/449 |
Current CPC
Class: |
B01D 35/043 20130101;
C02F 1/003 20130101; C02F 2209/445 20130101; B01D 24/008 20130101;
B01D 35/153 20130101; C02F 2201/006 20130101; C02F 1/008 20130101;
B01D 24/04 20130101; B01D 24/4861 20130101; B01D 35/147 20130101;
B01D 35/143 20130101 |
Class at
Publication: |
210/449 |
International
Class: |
B01D 035/00 |
Claims
What is claimed is:
1. A water filter cartridge for use in a water treatment device
having a mechanical totalization mechanism, a shut-off valve
mechanism which stops the flow of water after a predetermined
volume of water has been filtered, and a flow totalization reset
mechanism, the water filter cartridge comprising: (a) an outer
shell containing water treatment material and having a central
axis; (b) an inlet opening proximate a first end and an outlet
opening proximate a second end of said outer shell; (c) a cam
extending axially from said first end of said outer shell, such
that, when the filter cartridge is properly inserted into or
withdrawn from the water treatment device, said cam resets the flow
totalization mechanism.
2. A water filter cartridge as defined in claim 1, wherein said cam
includes a double sloping facade facing generally radially inward
toward said central axis, said facade actuating said flow
totalization reset mechanism upon axial insertion or withdrawal of
said filter cartridge.
3. A water filter cartridge as defined in claim 1, wherein said
shell includes a separate top which defines said first end and
includes said inlet opening and said axially extending cam.
4. A water filter cartridge as defined in claim 1, wherein said cam
and said inlet opening are radially displaced from said central
axis along respective radial lines and said radial lines are
approximately 90.degree. apart relative to one another.
5. A water filter cartridge for use in a water treatment device
having a chamber, comprising: (a) an outer shell containing water
treatment material and having a central axis; (b) an inlet opening
proximate a first end of said outer shell, said inlet opening being
radially displaced from said central axis; (c) an outlet opening
proximate a second end of said outer shell, said outlet opening
being generally co-axial with said central axis; (d) a channel in
said first end; (e) a notch in said first end, said notch being
radially displaced from said central axis in a direction opposite
said radial displacement of said inlet opening, and said notch
being in fluid communication with said channel; (f) whereby water
flows from said channel, through said notch, through the chamber of
the water treatment device, into said inlet opening, through said
water treatment material and out said outlet opening.
6. A water filter cartridge as defined in claim 5, wherein said
channel is annular and generally extends at least partially along a
periphery of said first end and said notch extends generally to
said periphery so as to fluidly communicate with said annular
channel.
7. A water filter cartridge as defined in claim 6, wherein said
annular channel extends along the entire periphery of said first
end.
8. A water filter cartridge as defined in claim 6, wherein said
notch includes a generally semi-circular portion and a flow passage
portion extending and providing fluid communication between said
annular channel and said generally semi-circular portion, said
generally semi-circular portion providing improved fluid flow with
the chamber of the water treatment device.
9. A water filter cartridge as defined in claim 5, the water
treatment device having a plate generally enclosing the chamber,
the plate including an opening defined by a first annular wall
having an inner diameter, wherein said first end of said outer
shell includes a second annular wall defining said inlet opening of
the cartridge, said second annular wall extending into the plate
opening and having an outside diameter approximately equal to the
inner diameter of the plate opening, thereby sealing the plate with
said inlet opening of the filter cartridge.
10. A water filter cartridge as defined in claim 9, wherein an
inner side of the first annular wall and an outer side of said
second annular wall are tapered for mating engagement so as to
provide improved sealing between the filter cartridge and the
chamber of the water treatment device.
11. A water filter cartridge as defined in claim 9, wherein said
first end includes an annular channel surrounding said second
annular wall, with the first annular wall of the plate extending
into said annular channel to provide better mating between the
plate and the filter cartridge.
12. A water filter cartridge for use in a water treatment device
having a mechanical totalization mechanism, a shut-off valve
mechanism which stops the flow of water after a predetermined
volume of water has been filtered, and a flow totalization reset
mechanism, the water filter cartridge comprising an outer shell
containing water treatment material and having a longitudinal axis,
an inlet opening, an outlet opening, and an actuating projection
extending from said outer shell generally parallel to said
longitudinal axis of said outer shell, such that, when the filter
cartridge is properly inserted into or withdrawn from the water
treatment device, said actuating projection resets the flow
totalization mechanism.
Description
[0001] This application is a continuation-in-part of application
Ser. No. 08/203,380, filed Mar. 8, 1994.
FIELD OF THE INVENTION
[0002] This invention relates generally to water treatment devices,
and more particularly to devices incorporating mechanisms for
end-of-life indication, automatic shutoff, resetting the automatic
shutoff and bypass, and to a filter cartridge for water treatment
devices.
BACKGROUND OF THE INVENTION
[0003] Water treatment devices for home and other use are well
known in the art. Such devices are incorporated into a water system
either in-line or at a terminal end. An example of the former would
be an under-the-counter device which filters water prior to
reaching the faucet. There are two common types of terminal end
devices--countertop and faucet-mounted. As compared to countertop
and under-the-sink devices, designing a faucet-mounted device
presents special challenges. These include making the device
sufficiently light so that it can be attached to a faucet and
sufficiently compact so that the device does not take up valuable
sink space.
[0004] Water treatment devices can treat water by the use of
mechanical filtration or chemical treatment. Mechanical filters
treat water by preventing passage of particulates. As a mechanical
filter approaches the end of its useful life, reduced or stopped
flow due to particulate accumulation provides a ready indication
that element replacement is necessary. By contrast, when the
capacity of a chemical element is exceeded, there is no such
indication. Chemical treatment is accomplished by processes such as
adsorption (e.g. charcoal media) and ion exchange (e.g. for lead
removal). Such chemical treatment eventually degrades and becomes
inactive. However, no indication is provided to the user that the
water is no longer being treated by the media. exchange (e.g. for
lead removal). Such chemical treatment eventually degrades and
becomes inactive. However, no indication is provided to the user
that the water is no longer being treated by the media.
[0005] As a result, various approaches have been taken to indicate
end of life to the user where it is not inherently provided by the
behavior of the filter media. One example is shown in U.S. Pat. No.
4,686,037. In this approach, a pre-filter is used to entrap
contaminants, and the color of the pre-filter is compared by the
user with a reference strip to determine when the media requires
replacement. The problem with this approach, however, is that it is
inherently subjective, and therefore subject to error. Also, the
user can easily forget to check the reference filter and mistakenly
believe the media is still purifying when it is not.
[0006] A much more accurate and foolproof means of indicating end
of life is through totalizing the volume which has passed through
the media and automatically shutting off flow after a predetermined
volume has passed through the device. Although the flow
totalization and shutoff valve mechanisms required are relatively
expensive and complex, this has become recognized as the most
accurate means of indicating end of life. For example, the
certifying agency in the United States for water treatment devices,
the National Sanitation Foundation, requires for certification of a
rated volume, twice the filter media capacity when an automatic
shutoff is not used, and only 20% additional capacity when an
automatic shutoff is employed.
[0007] Both electrical and mechanical approaches to flow
totalization are known in the prior art. Examples of the former are
shown in U.S. Pat. Nos. 4,918,426 and 5,089,144. In this approach,
flow rate is measured by, for example, a pressure transducer and
then integrated to calculate total volume. After a predetermined
volume has been reached, a valve is electrically actuated to stop
flow.
[0008] Examples of mechanical totalization in water treatment
devices are shown in U.S. Pat. Nos. 4,681,677 and 4,698,164. In the
mechanical approach, typically a turbine powered by water flowing
through the device is interconnected with a series of gears which
mechanically "add up" the volume of water which has passed through
the device. In turn, the gearing mechanism is interconnected with a
valve such that, after a predetermined volume of water has passed
through the device, the valve is mechanically actuated to stop flow
through the device.
[0009] However, prior art mechanical automatic shutoff mechanisms
suffer from certain shortcomings. One problem is that the
mechanisms employed, such as in the '677 patent, are too bulky to
be included in a compact device. Another problem with prior art
devices is that they make resetting the totalization and shutoff
mechanism unnecessarily difficult and/or expensive. For example, to
reset the device shown in the '677 patent, one would apparently
have to manually release the valve from the rotating cam and
manually disengage the gearing mechanism to reset the totalization
mechanism to a zero volume position. In the '164 patent, the valve
shutoff mechanism is incorporated into the replaceable cartridge,
and the shutoff valve is connected to the gearing mechanism upon
replacement of the cartridge. This approach is unnecessarily
wasteful and expensive because the shutoff valve is thrown away
with each cartridge, rather than being reused.
[0010] With respect to faucet-mounted water treatment devices, it
is not known in the prior art to incorporate automatic shutoff
end-of-life indication. This is due at least in part to the
obstacles associated with incorporating a mechanical flow
totalization and shutoff mechanism in the required compact size. As
a result, prior art devices have employed much cruder forms of
end-of-life indication, such as that discussed above in the '037
patent. Not only are prior art end-of-life indicating devices much
less accurate, but they are also unnecessarily wasteful due to the
more frequent cartridge replacement often required by certification
standards.
[0011] A feature that is common to faucet-mounted devices is the
ability to bypass or divert water from the filter media so that
untreated water can be obtained from the faucet. This is desirable
because it avoids unnecessary use of the filter media, allowing the
user to bypass the water treatment device if the water is not
intended for drinking, as for example for washing hands or
dishes.
[0012] Such a bypass mechanism is shown in the '037 patent. In this
approach, a separate handle is attached to the opposite end of the
mounting member to control a bypass valve. Other prior art devices
use this same approach, and therefore suffer from certain
disadvantages. The separate handle adds unnecessary complexity and
expense to manufacturing a bypass mechanism. Also, because of the
environment in which faucet-mounted devices are employed, there is
a significant problem with keeping such devices clean. A separate
handle only makes this more difficult, adding increased surface
area and creating difficult-to-clean crevices. Finally, the added
handle makes the appearance of the device less appealing, which is
a particularly important concern for faucet-mounted devices.
[0013] What has been needed is a compact, low-cost and
easy-to-manufacture water treatment device having an automatic
shutoff mechanism which is easy to reset. What has also been needed
is a faucet-mounted device incorporating automatic shutoff and a
simple bypass mechanism.
[0014] What has also been needed is a replacement filter cartridge
which can reset the flow totalization and shutoff mechanism upon
replacement of the cartridge and which provides a simple water flow
path and efficient sealing in communication with the water
treatment device.
SUMMARY OF THE INVENTION
[0015] According to the present invention, a water treatment device
having a replaceable filter cartridge is provided. The filter
cartridge can include mechanical or chemical filter media or a
combination thereof.
[0016] In one aspect of the invention, the water treatment device
includes an arrangement comprising a mechanism for mechanically
totalling the volume of water that has been filtered and a
mechanism for indicating when the replaceable filter cartridge has
reached the end of its useful life. End of life indication is
provided by a valve mechanism for stopping flow after a
predetermined volume has been filtered. The arrangement also
comprises a mechanism for resetting the flow totalization
mechanism, including a spring. The spring is connected with and
biased by the flow totalization mechanism, and a mechanism for
releasing the spring to reset the flow totalization mechanism is
included. The spring can be any of a variety of mechanical springs
which would be suitable for this purpose, including for example
torsional, coil, leaf, and helical springs in either compression or
tension.
[0017] In another aspect of the invention, the water treatment
device includes an arrangement comprising a shutoff valve which
closes to stop flow after a predetermined volume of water has
passed through the cartridge. The arrangement further includes a
spring which is loaded when the shutoff valve closes and a release
arm which causes the spring to unload and force the shutoff valve
open during replacement of the filter cartridge.
[0018] In another aspect of the invention, the water treatment
device includes an arrangement comprising a mechanism for
mechanically totalling the volume of water that has been filtered
and a mechanism for indicating end of life by stopping flow after a
predetermined volume has been filtered. A shutoff valve mechanism
is permanently contained within the device such that it is not
replaced upon replacement of the filter cartridge. The arrangement
also comprises a mechanism for resetting the flow totalization
mechanism, which includes a mechanism for resetting by replacement
of the filter cartridge.
[0019] The reset mechanisms of the present invention can be
employed not only in terminal-end water treatment devices, such as
faucet-mounted and counter-top, but also in in-line devices, such
as under-the-counter.
[0020] In another aspect of the invention, the water treatment
device comprises a faucet-mounted device. The faucet-mounted device
comprises a mechanism for indicating end of life by stopping flow
of water through the filter cartridge after a predetermined volume
of water has been filtered through the device.
[0021] In yet another aspect of the invention, the water treatment
device comprises a faucet-mounted device with a novel flow-bypass
design. The faucet-mounted device comprises a housing with a filter
element contained therein and having inlet and outlet openings. A
mounting member includes inlet and outlet ports, with the inlet
port being attachable to the faucet. A valve is in operable
connection with the mounting member and the housing and includes
first and second flow channels. The first flow channel extends
between the inlet port and the inlet opening, and the second flow
channel extends between the inlet and outlet ports. The valve body
is rotatable with respect to the mounting member between first and
second flow positions. In the first flow position, water flows from
the inlet port, through the first flow channel, into the inlet
opening of the housing, through the filter element and out the
outlet opening of the housing. In the second flow position, water
flows from the inlet port, through the second flow channel and out
the outlet port of the mounting member. Therefore, by rotation of
the housing, water is diverted from passing through the housing to
passing through the mounting member.
[0022] Also according to the present invention, a water filter
cartridge for use in a water treatment device is provided. In one
aspect of the invention, the water filter cartridge comprises an
outer shell containing water treatment material and having a
central axis. The filter cartridge further comprises an inlet
opening proximate a first end of the outer shell, an outlet opening
proximate a second end, and a cam extending axially from the first
end of the outer shell. When the filter cartridge is replaced, the
cam resets the flow totalization mechanism upon either insertion or
withdrawal of the cartridge (or both).
[0023] In another aspect of the invention, the water filter
cartridge comprises an outer shell, a radially displaced inlet
opening proximate a first end, and a generally coaxial outlet
opening proximate a second end. A channel and a notch in the first
end are in fluid communication with one another so as to provided a
flow path whereby water flows from the channel, through the notch,
through a chamber of the water treatment device, into the inlet
opening of the filter cartridge and out the outlet opening.
[0024] In yet another aspect of the invention, the water filter
cartridge comprises an outer shell containing water treatment
material and having a longitudinal axis, an inlet opening and an
outlet opening. An actuating projection extends from the outer
shell generally parallel to the longitudinal axis of the outer
shell. When the filter cartridge is replaced, the actuating
projection resets the flow totalization mechanism upon either
insertion or withdrawal of the cartridge (or both).
[0025] These and other advantages and features of novelty which
characterize the invention are pointed out with particularity in
the claims annexed hereto. However, for a better understanding of
the invention and its advantages, reference should be made to the
drawings which form a further part hereof, and to the accompanying
descriptive matter in which there is illustrated and described a
preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE FIGURES
[0026] FIG. 1 is an exploded perspective view of a water treatment
device according to the present invention;
[0027] FIG. 2 is a cross-sectional view of the water treatment
device shown in FIG. 1 as viewed generally from Section 2-2 of FIG.
4;
[0028] FIG. 3 is a partial cross-sectional view of the water
treatment device shown in FIG. 1 as viewed from Section 3-3 of FIG.
5;
[0029] FIG. 4 is a top partial cross-sectional view of the flow
shutoff mechanism of the present invention, with the mechanism in
the zero volume position;
[0030] FIG. 5 is a top partial cross-sectional view of the flow
shutoff mechanism of the present invention, with the flow shutoff
mechanism at the end-of-life position;
[0031] FIG. 6 is a top partial cross-sectional view of the flow
shutoff mechanism of the present invention, with the flow shutoff
mechanism in an intermediate position and the reset mechanism of
the present invention activated;
[0032] FIG. 7 is a cross-sectional view of a bypass mechanism
according to the present invention, with the flow diverted through
the mounting member;
[0033] FIG. 8 is an end cross-sectional view of the flow-bypass
mechanism shown in FIG. 7 as viewed from Section 8-8 of FIG. 7;
and
[0034] FIG. 9 is a partial cross-sectional view of a second
embodiment of a water treatment device and replacement filter
cartridge according to the present invention, having improved
sealing between the water treatment device and the inlet opening of
the replacement filter cartridge.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0035] Referring now to the drawings wherein like numerals
designate like parts, a faucet-mounted water treatment device 10 is
shown in FIGS. 1-8. Although water treatment device 10 is faucet
mounted, many of the novel features disclosed herein can be
incorporated into in-line or countertop devices as well.
[0036] Referring to FIGS. 1 and 2, water treatment device 10
includes housing 20 which comprises upper portion 22 and cap 24
which threads into upper portion 22. First O-ring 26 is provided in
channel 28 to create a watertight seal between upper portion 22 and
cap 24. Replaceable filter cartridge 40 is inserted into upper
portion 22 from below, and cap 24 is threaded to upper portion 22
to secure cartridge 40 in housing 20.
[0037] Water flows through housing 20 and cartridge 40 as follows.
Water enters housing 20 from valve body 30 at inlet opening 21 and
fills annular space 60 between cartridge 40 and housing 20,
including peripheral annular channel 62 formed in top 52 of
cartridge 40. As best shown in FIGS. 1 and 3, water then flows from
channel 62, into notch 64 of top 52 and up through cylindrical
portions 72, 82 of lower 70 and upper 80 plates, respectively.
Water is then directed out of jet 92 of top plate 90 (best shown in
FIG. 1) to turn blades 102 of turbine 100. Turbine 100 is tightly
nested in top plate 90, as best shown in FIG. 2, with minimum
clearance between blades 102 and top plate 90 to maximize turbine
efficiency. Water exits turbine 100 and passes through exit
cylinder 94 of top plate 90, which extends over second cylindrical
portion 84 of upper plate 80.
[0038] In normal operation (i.e. when flow has not been "shut
off"), water then flows into cartridge 40 through inlet opening 66
in top 52. While water primarily flows as described due to the
arrangement of the various parts, it should be understood that
water also fills chamber 68 generally defined between lower plate
70 up to upper portion 22 of housing 20. Water flows through
cartridge 40 by passing through filter disc 43, second screen 55,
first media 42, first screen 54, second media 44, and post filter
56, respectively, and then out through holes 49 in retainer 48.
Water then exits housing 20 from outlet opening 29. It will be
understood that outlet opening 29 could take on various
configurations and could be from various positions in housing 20,
although it is preferable that opening 29 be from bottom of housing
20.
[0039] Mounting member 110 is used to mount water treatment device
10 to a faucet (not shown). Adapter nut 112 defines inlet port 113
and is connected to body 114 by screen 116, which is shouldered by
adaptor nut 112 and sealingly held in annular channel 115 of body
114. Aerator 118 and aerator nub 120 are inserted into body 114
from below, with aerator 118 defining outlet port 119. Mounting
member body 114 extends over valve body 30, and they are sealed
together by third 122, fourth 123 and fifth 124 O-rings. Fifth
O-ring 124 surrounds extension 126 of body 114, which extends into
axial channel 34 of valve body 30. Axial channel 34 is preferably
tapered for ease of manufacturing by injection molding.
[0040] Valve body 30 is rotatable within mounting member 110
between two flow positions to allow the user to bypass cartridge 40
if desired. In the first flow position shown in FIG. 2, water flows
from inlet port 113, through first flow channel 32 defined by
radial 33 and axial 34 channels and into inlet opening 21 of
housing 20. In the second flow position shown in FIGS. 7 and 8,
water flows from inlet port 113, through C-shaped second channel 36
and out outlet port 119 of mounting member 110. It will be
understood by those skilled in the art that first 32 and second 36
channels can be configured in a variety of other ways to achieve
the result of diverting flow by rotation of housing 20. It will
also be understood that it is not required that valve body 30 be
molded as a single part with upper portion 22 of housing 20 as in
the preferred embodiment, although it is required that valve body
30 be fixedly connected to housing 20.
[0041] Water treatment device 10 includes an arrangement 15 for
indicating the useful life remaining in replaceable filter
cartridge 40. Arrangement 15 includes flow totalization mechanism
130 and shutoff valve mechanism 150. It will be understood by those
skilled in the art that a variety of totalization 130 and valve 150
mechanisms could be employed within the scope of the present
invention to achieve the same purpose. Arrangement 15 also includes
reset mechanism 160 for resetting totalization 130 and valve 150
mechanisms. In the preferred embodiment reset mechanism 160
includes biased spring 162 which is released by insertion of
cartridge 40. However, it will be understood by those skilled in
the art that spring 162 could be released by other means. It will
also be understood that totalization 130 and valve 150 mechanisms
could be reset by a variety of other mechanisms responsive to
insertion of cartridge 40 which do not incorporate a spring.
[0042] In the preferred totalization mechanism 130, turbine 100 is
connected with a plurality of gears 132 which in turn are connected
with a rotating sector 140. It will be understood that turbine 100
need not be directly connected to first gear 134 and that sector
140 need not be directly connected to last gear 136. Gears 132 are
successively interconnected, with each having a 10-to-1 ratio in
the preferred embodiment. Turbine 100 and two gears 132 are stacked
on first pin 138, and the remaining three gears 132, including
first 134 and last 136 gears are stacked on second pin 139. Pins
138, 139 are held in place from above by upper portion 22 of
housing 20. From below, first pin 138 is inserted into a hole in
upper plate 80, and second pin 139 is held in place by last gear
136, which extends through and is seated on raised portion 86 of
upper plate 80.
[0043] Last gear 136 is connected to sector 140 by pinion 137 of
last gear 136 engaging teeth 142 of sector 140, as best shown in
FIGS. 4 and 5. Thus, as turbine 100 rotates, gears 132 are
successively rotated, causing sector 140 to be rotated by pinion
137 and thereby "adding up" the volume of water that has passed
through cartridge 40.
[0044] The preferred shutoff valve mechanism 150 includes ball 152,
which is held by and rotated with sector 140, and flow inlet
opening 66 of filter cartridge 40. Shutoff mechanism 150 starts in
a zero volume position, as shown in FIGS. 2 and 4. After
totalization mechanism 130 has rotated sector 140 to the flow stop
position, as shown in FIGS. 3 and 5, ball 152 becomes seated in
inlet opening 66 of cartridge 40, which is formed by raised portion
51 of top 52 extending through lower plate 70. It will be
understood by those skilled in the art that a variety of other
suitable mechanical valve mechanisms could also be employed.
[0045] Reset mechanism 160 includes spring 162 which is connected
to and wound by sector 140 as sector 140 rotates. It will be
understood that, while the preferred embodiment employs a wound
coil spring 162, numerous other types of springs as discussed
hereinabove and a variety of other arrangements and connections
could be employed whereby a spring is biased by a flow totalization
mechanism. To release spring 162 in the preferred embodiment,
pinion 137 is radially disengaged from teeth 142 of sector 140,
thereby causing sector 140 to be rotated back to the zero volume
position by spring 162, as shown in FIG. 6. It will be understood
that teeth 142 and pinion 137 could also be separated axially to
achieve the same result.
[0046] In the preferred embodiment, spring 162 is released by a
transverse movement of slide 164 acting as a release arm. Slide 164
includes vertical extension 165 onto which sector 140 and spring
162 are rotatably mounted. Spring 162 includes levers 163 extending
from opposite ends, with one of levers 163 abutting stop 144 on
sector 140 and the other lever 163 abutting fixed stop 74 on lower
plate 70. This arrangement allows spring 162 to serve both the
functions of resetting sector 140 and returning slide 164 to its
unslid position because spring 162 resists torsional movement of
sector 140 as well as transverse movement of slide 164. Slide 164
is held in line by guides 76 on lower plate 70. The components
between upper 80 and lower 70 plates are held together by screws 88
inserted from below, as shown in FIG. 1.
[0047] In the preferred embodiment, slide 164 is slid by insertion
and removal of filter cartridge 40. It will be understood that
slide 164 could be moved in a variety of other ways, such as by
pushing a button to reset totalization mechanism 130. It will also
be understood that totalization mechanism 130 could also be reset
by a variety of other mechanisms which are responsive to
replacement of cartridge 40. For example, a mechanism could be
constructed such that insertion of cartridge 40 causes last gear
136 to axially separate from sector 140, or that causes separation
and turning of sector 140 without use of a spring 164.
[0048] In the preferred arrangement, slide 164 is slid by cam 53
projecting axially from top 52 of cartridge 40, thus actuating
reset mechanism 160. When cartridge 40 is axially inserted into
housing 20, cam extends through opening 78 in lower plate 70 and
abuts cam follower surface 166 on slide 164 to move slide 164
transversely. Those skilled in the art will recognize that cam 53
need not necessarily be a separate projection, but can form part of
for example an inlet or outlet opening projecting from the
cartridge to actuate reset mechanism 160. Cam 53 includes a double
sloping facade facing radially inwardly. Although cam 53 can take
on a variety of other shapes, in the preferred embodiment the
sloped facade is generally symmetric. As a result, slide 164 is
slid transversely both upon insertion and removal of cartridge 40.
Necessarily therefore, while totalization mechanism 130 in normal
operation will already be returned to a zero volume position upon
removal of cartridge 40, the mechanism 130 is "reset" through
transverse movement of slide 164 by both insertion and withdrawal
of cam 53 in the preferred design. Within the principles of the
invention, however, the cam could be designed so as to reset the
flow totalization mechanism upon either insertion or removal or
both.
[0049] In addition to providing a flow stop indication of end of
life, a continuous visual indication of the amount of useful life
remaining in replaceable filter cartridge 40 is provided in the
preferred embodiment. This is accomplished by colored screen 146 at
the end of sector 140, which is visible through lens 170 as sector
140 rotates. Referring to FIG. 1, lens 170 is inserted into slot 23
of upper portion 22 of housing 20, and is sealed by gasket 171.
[0050] In the preferred embodiment, cartridge 40 comprises two
chemical filter media, including first media 42, which comprises an
ion exchange resin suitable for removing lead, and second media 44,
which comprises Granular Activated Charcoal ("GAC"). Mechanical or
other chemical filter media can also be employed within the scope
of the invention in various numbers or combinations. In the
preferred cartridge 40, media 42, 44 are enclosed by base 46,
O-ring retainer 48 which is friction fit with an inwardly extending
cylindrical portion 50 of base 46, and top 52 which is friction fit
with an inner side of the upper portion of base 46. Base 46
includes shoulder 47 which is supported by cap 24 to push cartridge
40 upwardly into housing 20. Retainer 48 holds second O-ring 27 in
place to create a seal between retainer 48, cylindrical portion 50
and inward extension 25 of cap 24. Water exits cartridge 40 through
holes 49 in retainer 48.
[0051] Within cartridge 40, filter media 42, 44 (not shown in FIG.
1) are separated by first screen 54, and second screen 55 separates
first media 42 from filter disc 43 which is held between top 52 and
second screen 55. Filter disc 43 is made of white filter paper and
is for the purpose of providing the user with a visual reference to
assure the user that cartridge 40 is performing its function and to
indicate whether a particular cartridge has been used. In the
preferred embodiment, top 52 is clear so that the user can see if
disc 43 has gathered contaminants, indicating that the cartridge 40
has been used. U-shaped post filter 56 extends over cylindrical
portion 50 to prevent GAC from being flushed out, and post filter
cap 57 extends over filter 56 to direct the flow of water to bottom
of cartridge 46 to assure that the entire second media 44 is
utilized.
[0052] Water flows through cartridge 40 as follows. Unfiltered
water fills peripheral annular channel 62 in top 52 and then into
notch 64 from which it flows upwardly through cylindrical portion
72 of lower plate 70. Those skilled in the art will recognize that
channel 62 and notch 64 could take on a variety of other shapes to
provide fluid communication between the periphery of top 52 and the
semicircular portion of notch 64. For example, channel 62 could
extend across top 52 to reach notch 64, and channel 62 need not
necessarily be open but could pass through top 52 under the
surface. Further, annular channel 62 need not extend entirely
around the periphery of top 52 and could have an enclosing outer
wall. Notch 64 preferably has a semi-circular shape to provide
optimal fluid communication with cylindrical portion 72 of lower
plate 70. The remaining flow passage portion of notch 64 connects
the semi-circular portion with annular channel 62 in the preferred
embodiment and could be shaped in a variety of ways to suit this
purpose.
[0053] Referring now to FIG. 9, a second embodiment having improved
mating between top 52 of cartridge 40 and lower plate 70, which
encloses chamber 68, is shown. Ideally, all of the water entering
inlet opening 66 of cartridge 40 should come from chamber 68.
Otherwise water leaking from between lower plate 70 and cartridge
top 52 into chamber 68 will have bypassed the flow totalization
mechanism 130 causing totalization inaccuracies (i.e.,
under-totalization) relative to the volume of water actually
filtered. Therefore, the preferred design includes a structure
which provides better sealing between lower plate 70 and inlet
opening 66 of filter cartridge 40. In the preferred design, lower
plate 70 includes an annular wall 200 which extends toward top 52
of cartridge 40. A corresponding second annular wall 201 extends
into opening 78 of lower plate 70, with the outer diameter of
second annular wall 201 providing a friction fit with the inner
diameter of first annular wall 200. Annular walls 200, 201 are
preferably tapered for mating engagement to provide better sealing.
First annular wall 200 of top 52 extends into annular channel 203
formed in top 52 and surrounding second annular wall 201. This
permits contact between annular walls 200, 201 along an increased
distance as well as provides a positive indication of mating
between lower plate 70 and top 52 of cartridge 40.
[0054] It should be understood that the present invention is not
limited to the preferred embodiment discussed above, which is
illustrative only. Changes may be made in detail, especially
matters of shape, size, arrangement of parts, or material of
components within the principles of the invention to the full
extent indicated by the broad general meanings of the terms in
which the appended claims are expressed.
* * * * *