U.S. patent application number 11/699125 was filed with the patent office on 2007-08-23 for housing for environmentally friendly filter cartridge.
This patent application is currently assigned to Baldwin Filters, Inc.. Invention is credited to Gene W. Brown, Steven J. Merritt.
Application Number | 20070193929 11/699125 |
Document ID | / |
Family ID | 27613570 |
Filed Date | 2007-08-23 |
United States Patent
Application |
20070193929 |
Kind Code |
A1 |
Brown; Gene W. ; et
al. |
August 23, 2007 |
Housing for environmentally friendly filter cartridge
Abstract
A filter system in which a housing and an environmentally
friendly filter cartridge are coordinated to provide ease of change
of the filter cartridge and reliable operation. The cartridge
contains no metal parts and is readily incinerateable. The housing
is provided with a number of "universality" features including a
changeable bottom which allows the housing to operate as a fuel
filter, a lubrication filter, or a hydraulic filter in different
applications. The housing and cartridge are configured to provide
support for the plastic elements of the cartridge to prevent
crushing of the filter under normal and abnormal filter operating
conditions. A key system associated with the cartridge and the
housing provides assurance that the correct filter is installed for
a particular application.
Inventors: |
Brown; Gene W.; (kearney,
NE) ; Merritt; Steven J.; (Kearney, NE) |
Correspondence
Address: |
LEYDIG VOIT & MAYER, LTD
TWO PRUDENTIAL PLAZA, SUITE 4900
180 NORTH STETSON AVENUE
CHICAGO
IL
60601-6731
US
|
Assignee: |
Baldwin Filters, Inc.
Kearney
NE
|
Family ID: |
27613570 |
Appl. No.: |
11/699125 |
Filed: |
January 29, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10457733 |
Jun 9, 2003 |
7182864 |
|
|
11699125 |
Jan 29, 2007 |
|
|
|
60387235 |
Jun 7, 2002 |
|
|
|
Current U.S.
Class: |
210/90 ; 210/450;
210/455 |
Current CPC
Class: |
B01D 46/4272 20130101;
B01D 2201/304 20130101; C10M 175/0091 20130101; B01D 29/96
20130101; B01D 29/15 20130101; B01D 46/446 20130101; B01D 35/31
20130101; B01D 35/143 20130101; B01D 2201/0415 20130101; B01D
2201/20 20130101; B01D 29/21 20130101; B01D 29/58 20130101; B01D
46/2414 20130101; B01D 35/303 20130101; B01D 2201/34 20130101; B01D
2201/208 20130101; B01D 2201/295 20130101; B01D 29/608 20130101;
B01D 2201/4046 20130101; B01D 2271/02 20130101; C10N 2040/252
20200501; B01D 35/18 20130101; B01D 2201/24 20130101 |
Class at
Publication: |
210/090 ;
210/450; 210/455 |
International
Class: |
B01D 35/00 20060101
B01D035/00 |
Claims
1-16. (canceled)
17. A filter housing bank comprising a plurality of filter housing,
wherein each filter housing comprises in combination: a housing for
receiving a filter cartridge which separates an unfiltered region
from a filtered region in the housing, a removable cover on the
housing, the housing having a back which includes mounting features
for mounting a plurality of said housings side-by-side in a bank,
the housing having a front in which is formed an inlet port and an
outlet port connected to the unfiltered region and filtered region
respectively, the inlet port and the outlet port being vertically
displaced from each other on the front of said housing, tee
fittings on the inlet and the outlet ports, each tee fitting being
a unitary device having a short trunk and a T-arm in fluid
communication with the trunk and having oppositely directed
connection ports the trunk being connected to the associated port,
at least some of the tee fittings having a valve movable inside the
associated trunk and forming a seal with a cooperating seat in the
trunk for shutting off the trunk from the associated T-arm, the
valve bank including tubing connecting the connection ports of the
T-arms of adjacent filter housings to connect said filter housings
in parallel.
18. The filter housing bank of claim 17 including at least two
filter housings each requiring a filter of different
characteristics, two filter cartridges of said different
characteristics, one for each of said housings, and each of the
housings and filters including a keying mechanism for associating
one of said filter cartridges with the associated housing and
preventing installation of said one filter cartridge in the other
housing.
19. The filter housing bank of claim 18 in which each housing has a
threaded upper section for receiving the cover, the cover having a
two section rim of approximately the same internal diameter and
capable of fitting over the threads on the housing, a first lower
portion of the rim being sized to slip over the threads to lead the
cover to the upper portion of the rim which is threaded, whereby
the lower portion tends to align the cover before the threads
engage to prevent cross threading.
20. The filter housing bank of claim 18 wherein at least one of the
housings includes a plugged filter indicator, the indicator being
connected to the housing and having connections for sensing
upstream and downstream pressure in the unfiltered and filtered
regions respectively.
21. The filter housing bank of claim 20 in which the plugged filter
indicator further includes: a piston supported by a spring
calibrated to a desired pressure differential, the spring driving
the piston to a rest position in the normal operating condition,
the upstream and downstream pressures being ported to opposite
sides of the piston to move the piston from the normal to the
plugged filter position upon indication of a pressure condition
indicative of a plugged filter, an indicator button which is spring
loaded to an extended position but which has an armature attracted
to the magnet of the piston when the piston is in the rest position
to prevent exposure of the indicator, whereby displacement of the
piston in response to a plugged filter condition releases the
indicator for display.
22. The filter housing of claim 21 further including a manual reset
for the plugged filter indicator to cause the armature to be
reattracted to the magnet in the piston after the plugged filter
condition has passed.
23. The filter housing of claim 17 wherein the valve in the tee
includes a threaded port having a rotateable plug therein, the
rotateable plug having a plug member having a first position for
closing off the trunk and a second position for connecting the
trunk to the T-arm.
24. The filter housing of claim 18 wherein the valve in the tee
includes a threaded port having a rotateable plug therein, the
rotateable plug having a plug member having a first position for
closing off the trunk and a second position for connecting the
trunk to the T-arm.
25. The filter housing of claim 21 wherein the valve in the tee
includes a threaded port having a rotateable plug therein, the
rotateable plug having a plug member having a first position for
closing off the trunk and a second position for connecting the
trunk to the T-arm.
Description
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] This patent application is a divisional of copending U.S.
patent application Ser. No. 10/457,733, filed Jun. 9, 2003, which
claims the benefit of U.S. Provisional Patent Application No.
60/387,235, filed Jun. 7, 2002, both of which are incorporated by
reference in their entirety herein.
FIELD OF THE INVENTION
[0002] This invention pertains to filters, and more particularly to
a filter system using an environmentally friendly filter
cartridge.
BACKGROUND OF THE INVENTION
[0003] Most conventional filters and filter cartridges present a
disposal problem. Driven by ease of installation, many applications
have gone to self-contained spin-on cartridges. These have a metal
outer case, a metal base plate, and other metal components within
the filter. Replaceable cartridges also have significant metal
components, often in the form of centertubes or support grids for
supporting the filter element, and metal endcaps. Thus, significant
elements of a filter will not burn thus preventing the use of
incineration for relatively complete disposal of the spent filters
or filter cartridges.
BRIEF SUMMARY OF THE INVENTION
[0004] In view of the foregoing, it is a general aim of the present
invention to provide a filter system capable of supporting and
reliably using an environmentally friendly filter cartridge, such
that when the cartridge is spent it can be incinerated. The
cartridge is environmentally friendly in that it contains no
metallic parts.
[0005] It is a feature of the invention that plastic endcaps are
utilized in the filter cartridge, and the housing has structure
which cooperates with the filter cartridge to compensate for the
reduction in strength of plastic endcaps over conventional metal
endcaps.
[0006] In a particular embodiment the invention provides a filter
system based on a housing having a closed bottom and a removable
cover. A filter cartridge is provided for insertion into the
housing and for securing therein by locking the removable cover on
the housing. The cartridge is in the form of an open center
cylinder which has no metallic parts. The housing has, at its base,
an upstanding annular flange which has a diameter about the same as
the outer diameter of the cartridge. The cartridge carries a radial
seal in the form of a depending skirt fixed to a lower endcap. The
skirt has a diameter which causes the skirt to overlie the annular
flange such that when the filter is in operation, internal pressure
creates a radial seal between the skirt and the flange. The
cartridge also has an upper endcap which carries an axial seal
positioned to fit between the housing and the cover when the cover
is in its locked position. The system provides cooperating supports
and stops on the inside of the housing and the lower portion of the
upper endcap to provide a positive seat and stop which prevents
operating pressure from forcing the upper endcap into the filter
beyond its seated position.
[0007] In another aspect, the invention provides a filter housing
of universal characteristics for cooperating with a filter
cartridge to filter fluid. A housing is provided for receiving a
filter cartridge which separates an unfiltered region from a
filtered region in the housing. The housing has a front in which is
formed an inlet port and an outlet port connected to the unfiltered
region and filtered region respectively, and also connected to at
least one accessory port. A removable cover is threaded onto the
top of the housing and removable for allowing access to and
interchange of the cartridge. The housing has bolted on removable
base selected from the group consisting of a sump for fuel filter
applications, and a rigidified bottom for high pressure
applications.
[0008] In another aspect, the invention provides a filter housing
in an interconnected filter housing bank, wherein each filter
housing is adapted to receive a filter cartridge which separates an
unfiltered region from a filtered region in the housing. The
housing has a back which includes mounting features for mounting a
plurality of said housings side-by-side in a bank. The housing has
a front in which is formed an inlet port and an outlet port
connected to the unfiltered region and filtered region
respectively. The inlet port and outlet port are vertically
displaced from each on the front of said housing. Tee fittings are
connected on the inlet and outlet ports. Each tee fitting has a
trunk connected to the associated port and a T-arm in fluid
communication with the trunk. At least some of the tee fittings
having a valve for shutting off the trunk from the T-arm. The valve
bank including tubing connecting the T-arms of adjacent filter
housings to connect the filter housings and parallel.
[0009] In connection with the foregoing aspect of the invention,
the filter bank also includes at least two filter housings, each
requiring a filter of different characteristics. Two filter
cartridges of the different characteristics, one for each of said
housings, and each of the housings and filters including a keying
mechanism for associating one of the filter cartridges with the
associated housing and preventing installation of said one filter
cartridge in the other housing.
[0010] Other aspects, objectives and advantages of the invention
will become more apparent from the following detailed description
when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a front elevation of one form of housing
constructed in accordance with the present invention;
[0012] FIG. 2 is a rear elevation of the housing of FIG. 1;
[0013] FIG. 3 is a cross-sectional view taken generally along the
line 3-3 of FIG. 5 illustrating the relationship between the filter
cartridge and the filter housing in a filter system similar to that
of FIG. 1;
[0014] FIG. 4 is a front elevation showing two filter housings
assembled in a filter bank;
[0015] FIG. 5 shows a variation of the housing of FIG. 1 having a
different bottom constructed for higher pressure applications;
[0016] FIG. 6 shows a filter housing with cover removed exposing
the top of the filter cartridge;
[0017] FIG. 7 is a sectional view through a filter housing showing
the relationship between the cartridge and the housing and
illustrating some of the system accessories;
[0018] FIG. 8 is a partial view of the area of FIG. 7 indicated by
the circle 8 better illustrating the locking of the cover to the
housing and compressing of the axial seal gasket;
[0019] FIG. 9 is a cross-sectional view illustrating the plugged
filter indicator;
[0020] FIG. 10 is a view showing the valve associated with the
inlets and outlets;
[0021] FIGS. 11 and 12 diagrammatically illustrate the keying of
filters to the filter housing; and
[0022] FIG. 13 is an elevational view of a typical filter
cartridge.
[0023] While the invention will be described in connection with
certain preferred embodiments, there is no intent to limit it to
those embodiments. On the contrary, the intent is to cover all
alternatives, modifications and equivalents as included within the
spirit and scope of the invention as defined by the appended
claims.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] The disclosed housing in the present application will be
described primarily in connection with fuel filters. The housing is
designed for multiple parallel plumbing of fuel filters, as will be
described in connection with FIG. 4. The housing, however, can also
be used to form a full flow oil filter, a hydraulic filter or a
bypass filter. Some of these applications will also be illustrated
to show the universality of the filter system.
[0025] Turning then to the drawings, and particularly to FIGS. 1
and 2, there are shown many of the basic elements of the housing
portion of a filter system 20 constructed in accordance with the
present invention. The system 20 is based on a housing 21 which has
a plurality of ports 22 on the face thereof which allow
configuration for a variety of applications. Of significance, the
housing 21 is provided with a removable base 24; as will be
described below, a number of different bases 24 can be provided to
alter the application for which the filter system is used. The
bottom 24 is secured to the housing 21 by a secure mounting
structure, such as the threaded fasteners 25 illustrated in the
drawings. Preferably cap screws 25 are used at four locations to
secure the bottom in place; since the bottom will not typically be
removed after the housing is dedicated to a particular
installation, the attachment can be relatively permanent. The
advantages of the ability to bolt a different bottom in place are
achieved primarily in the manufacturing stage when a run of filters
for a particular application is being made. The application shown
in FIGS. 1 and 2 is primarily for use as a fuel filter.
[0026] The housing 21 has a removable cover 26. Complementary
threads (not shown in FIGS. 1 and 2) on the inside of the cover 26
and on the outside of the housing 21 allow the cover to be screwed
onto the top of the housing. As will also be described, an internal
filter cartridge carries an axial seal gasket which is trapped
between sealing faces of the cover and housing for preventing
leakage between those elements.
[0027] FIG. 2 illustrates four mounting bosses 30 on the back of
the housing 21. The mounting bosses are preferably threaded to
allow one or more filters to be mounted on a plate, with the plate
then mounted in the position where the filters will be utilized.
FIG. 4, for example, shows a gang of two filters in which a plate
32 supports both filters. A bolt passed through the plate and into
the tapped bosses 30 securely attaches the individual filters to
the plate, whereupon the plurality of filters can be treated as a
multiple filter bank for unitary mounting.
[0028] As noted above, the unit illustrated in FIGS. 1, 2 and 4 is
intended primarily in fuel filter applications. As such, the bottom
assembly 24 includes a sump 34 which is typically used to collect
water and other debris in a fuel filter application. Preferably the
sump 34 is of see through plastic and includes a self-venting drain
valve 35 for periodically removing the collected impurities.
[0029] FIG. 3 is intended to illustrate the relationship between
the housing 21 and the filter cartridge which it contains. For
purposes of illustration, FIG. 3 shows a cross-sectional view for a
filter which is slightly different from the fuel filter, namely a
lubrication filter. In effect, FIG. 3 is a section of the
lubrication filter shown in FIG. 5. The components are
substantially the same as those in FIGS. 1 and 2, except many of
the peripheral and accessory components associated with a fuel
filter are removed. The description of the housing, unless
otherwise noted, would be the same for both the fuel filter and
hydraulic filter applications.
[0030] FIGS. 3 and 8 illustrate certain of the internal elements of
the filter system 20. A cylindrical filter cartridge 50 fits within
the housing 21. The cartridge is inserted by removing the cover 26,
dropping a cartridge 50 in place, then reattaching the cover 26. In
the illustrated embodiment flow through the filter is from the
outside in. Thus an exterior region 51 outside the periphery of the
filter is dedicated to unfiltered fluid, while a region 52 within
the bore of the filter is dedicated to filtered fluid. As will be
understood by those skilled in this art, flow through the filter
from the unfiltered region 51 to the filtered region 52 serves to
remove impurities as the fluid passes through the filter
medium.
[0031] The cartridge 50 includes a filter element 53 having an
upper endcap 54 and a lower endcap 55. The lower endcap 55 has a
radial seal gasket 56 associated therewith which interacts with an
annular flange 57 on the housing base to provide a highly effective
but simple radial seal 56 at the lower end of the filter separating
the unfiltered region 51 from the filtered region 52. An axial seal
102 is carried by the upper endcap 54 and is pinched between an
inside shoulder 58 of the cover 26 and a mating shoulder 59 of the
filter housing.
[0032] An inlet port 40 penetrates the wall of the housing 21 and
is in fluid communication with the unfiltered region 51, as best
shown in FIG. 3. An outlet port 42 is also provided on the exterior
of the housing, in this case being formed in the baseplate 24
itself. The outlet port 42 communicates through an internal channel
43 (see FIG. 3) to the filtered fluid region 52. Thus fluid which
passes through the inlet 40 passes through the filter element 53 to
the clean region 52 in the bore of the cartridge, thereupon passes
through the channel 43 in the outlet port 42 to the utilization
device, usually an engine.
[0033] Other peripheral elements are also illustrated in connection
with FIG. 1, including a thermostat valve 45 which is provided
primarily in fuel filter applications where it is desired to
utilize a liquid heater for raising the temperature of the fuel. A
warm fluid is passed through the thermostat valve 45 to coils 46
internal to the filter (see FIG. 7 where they serve to heat the
fluid). A pair of ports 49 are provided, and are associated with
the thermostat 45 in FIG. 1. The ports 49 are connected to an
internal coil 46 which is illustrated in FIG. 7. The unit can also
be provided with an electric heater 60 (see FIG. 7). Wires 62
penetrate a sealed aperture 63 in the baseplate 24 for making
connections to the internal heater 60.
[0034] A further port in the housing 21 allows connection of a
plugged filter indicator 48 which will be described in greater
detail below. It suffices to say for the moment, the plugged filter
element 48 has a port which is connected to both the filtered and
unfiltered regions 51, 52 (in FIG. 3) to measure differential
pressure across the filter and, by that mechanism, determine when
the filter is sufficiently plugged to raise an alarm.
[0035] While all of the elements associated with the system 20 will
not be described in detail, they do emphasize an inventive aspect
of the invention, namely the extreme flexibility which is provided
by the multiple ported housing with adaptable baseplate and
changeable (and keyed) filter cartridge arrangement.
[0036] FIG. 4 illustrates the features of the invention which
simplify arranging individual filter housings 21 in a bank. Using
the mounting bosses 30 on the back of the filter, a plurality of
filter housings 21 are mounted in a single bank 70. The bank is
based on the plate 32 to which the filter housings 21 are bolted,
and itself has mounting holes 72 for securing the filter bank 70 to
structure. It is seen that the inlet ports 40 and outlet ports 42
are in different horizontal planes when the filters are mounted in
a gang, and this simplifies interconnection between filters and
also connections to external elements. The inlet and outlet ports
40, 42 are provided with special tee type fittings in accordance
with the invention. Referring concurrently to FIG. 4 which shows
the filter bank and FIG. 10 which shows one of the tee fittings, it
will be seen that each of the tee fittings includes a trunk 74
which is connected to the associated port 40 or 42. Fluidically
connected to each trunk 74 is a T-arm 76 having oppositely directed
ports 77, 78 referring to FIG. 4. With the tee fittings arranged in
this manner, it is relatively simple to plumb the filter units in
parallel. Connector tubes 80 are connected between associated ports
77, 78 as illustrated. The ports 77, 78 are preferably 0-ring and
threaded ports for tube connections, so that tube sections 80 are
relatively easily and reliably connected between the two. Ports not
used can readily be plugged. With the arrangement illustrated in
FIG. 4, a plug 82 is located in the left hand most port 77 on the
outlet side, and in the right most port 78 on the inlet side. The
left hand most port 77 on the inlet side is connected to a supply
as suggested at 83, and a right hand most port 78 on the outlet
side is connected to a conduit which runs to the engine as
suggested at 84. With the illustrated configuration, both housings
21 are connected in parallel to accept unfiltered fuel from the
supply 83 and supply filtered fuel via conduit 84 to the
engine.
[0037] It is feature of the invention that individual filters in
the housings 21 can be changed without shutting the engine down. To
that end, each of the tee connectors 73 can be provided with a
valving arrangement indicated generally at 86. The valve is
arranged to allow shut-off of the connection between the trunk 74
and the T-arm 76, but without interfering with flow through the
T-arm. Thus, if one of the filters is to be shut-down for changing
a filter, the associated valves 86 can be moved to the closed
position, at which point there is no flow into or out of the
associated filter, whereas the flow continues from the supply to
the engine through the other filter or filters in the bank. With
the valve 86 shut-down, the cover can be removed, the filter
changed, the cover replaced, then the valve reopened so that normal
operation can continue. A filter can be changed without shutting
down the engine.
[0038] In contrast to relatively expensive ball valves used in the
past, the present invention utilizes a simple plug valve as best
illustrated in FIG. 10. A threaded portion 88 of the valve body 89
is fit with a threaded plug 90. A threaded plug has a closure
section 92. In the position illustrated in FIG. 10, the valve is
closed, since it will be seen that the flow from the trunk 74 to
the T-arm 76 is not possible, having been blocked by the plug
portion 92. When it is desired to open the filter to flow, the plug
is rotated counterclockwise, to draw the plug 90 further out of the
valve, moving the plug member 92 to a position where it does not
block the passage connecting the trunk to the T-arm.
[0039] The ability to change filters without shutting down the
engine is a desirable situation in many applications, such as on an
electric generating system or a marine application, or other types
of applications where the engine runs continuously. By their
nature, fuel filters are changed more frequently than other
filters, and being able to change them without interrupting the
flow of fuel is desirable. It is also noted that plugs are inserted
in most of the feature ports in the system of FIG. 4. This is not
only to simplify the drawings and to illustrate the parallel
plumbing between inlets and outlets, but also to emphasize the
point that in its simplest application, the filter can be supplied
without most of the special features, for relatively simple, for
example, warm weather, applications.
[0040] FIG. 5 shows additional versatility in the system, primarily
in the ability to interchange bottom plates to change the
application to which the filter is directed. Whereas the filter
units of FIGS. 1, 2 and 4 all had a sump bowl and were arranged for
fuel filter application, the filter unit 21a of FIG. 5 is arranged
for hydraulic and oil filter applications. The primary difference
between the filters, in addition to dispensing with most of the
peripheral attachments, is the provision of a different baseplate
24a. In contrast to the baseplate 24 which included a provision for
a fuel bowl, the baseplate 24a has a rigidified bottom 91 adapted
to resist substantially higher pressures. Thus, the housing, being
configured for higher pressures, is adaptable to ordinary
lubricating applications as well as higher pressure hydraulic
applications. In contrast to the relatively low pressures
encountered in fuel filter applications, pressures as high as 150
psi can be encountered in lubrication applications, and as high as
800 psi in hydraulic applications. The base 24a also has, similar
to the channel 43 of FIG. 3, an internal connection between the
outlet port 42 and the filtered region. Similarly the baseplate 24a
will have a raised flange 57 for cooperating with a radial seal
gasket on the hydraulic filter to be inserted in the housing of
FIG. 5.
[0041] FIG. 6 illustrates the system with the cover 26 removed. It
will be seen that with the cover removed, the upper portion of the
cartridge 50 is exposed, particularly the upper endcap 54 thereof.
Also shown is the upper axial seal gasket 102 which is compressed
between the flange 59 formed on the housing and a corresponding
flange 58 (see FIG. 8) on the cover. The cartridge 50 conveniently
has its own handle 106 to allow ready removal of the cartridge from
the housing once the cover is removed.
[0042] FIG. 7 is primarily illustrates the variety of accessories
which can be provided with a cartridge according to the present
invention. The fluid heater 46 connected to ports 49 has already
been mentioned. An auxiliary electrical heater 60 connected to
external wires is also provided. The self-venting drain valve 35 at
the lower end of the fuel bowl 34 is illustrated in cross-section.
An electrical water-indicator 104 is also included which can sense
water in the material in the fuel bowl and light a signal
light.
[0043] The cartridge 50 is an integral part of the system. It is
environmentally friendly in that it contains no metallic parts. As
such, a centertube, when one is needed, is provided by the housing.
For example, FIG. 3 illustrates a centertube 120, carried by the
base 24 and supporting the otherwise unsupported inner bore of the
cartridge 50.
[0044] The cartridge includes endcaps 54, 55, which are normally
made of metal. In the present case, however, they are made of
plastic. In practicing this aspect of the invention, provision is
made for accommodating for the reduced strength of these materials.
For example, the upper endcap 54 would tend to bow with pressures
inside the filter. To alleviate that a pressure equalization
aperture 122 is provided in the rim of the upper endcap 54 to allow
the high pressure from the unfiltered zone 51 to appear at the top
of the upper endcap 54. Having thus relieved that problem, however,
in a plugged filter condition, the high pressure on the top of the
filter would tend to force the upper endcap 54 downwardly,
attempting to crush the filter element of the otherwise unsupported
filter. To prevent that, the upper endcap 54 is securely supported
in the housing structure itself. Thus it will be seen that the
upper endcap is provided with angled projections such as ribs 124
which serve to center the filter by riding over projection 125 in
the housing. Projections 124 have lower shoulders 126 which seat on
a ridge 127 on the interior of the housing 21. Thus, when the
filter is properly positioned, the shoulders 126 will seat upon and
travel no farther than the ridge 127. Even in a plugged filter
condition, the pressures will not be capable of driving the endcap
54 down further than this position, preventing crushing of the
filter in this situation.
[0045] With respect to gasketing, it will be seen that the upper
axial seal gasket 102 is a simple disc-like structure which is
carried in a groove 102a in the upper endcap. Preferably the rubber
gasket is sized so that it is snapped in place in the groove 102a
for reliable retention.
[0046] The lower gasket 56 is similarly fit within a groove 56a in
the lower endcap, and snapped in place for reliable retention as
shown in FIG. 3. The lower gasket has a skirt 130 which overlies an
upstanding annular flange 132 in the base of the filter housing.
With pressure in the unfiltered region 51 being higher than
pressure in the clean region 52, the operating pressure in the
filter tends to force the skirt 130 against the flange 132,
maintaining the effectiveness of the seal. This same pressure which
forces the skirt 130 against the flange 132 also forces the skirt
130 against the endcap 55, rendering the seal even more reliable.
Finally, positioning the lower radial seal gasket 56 at the outer
periphery of the housing lends additional benefit in keeping the
lower endcap 55 with a slight pressure differential in the downward
direction. The bottom of the endcap 55 is in the clean region 52 of
the filter and thus at a lower pressure. The upper endcap 54 is at
a somewhat higher pressure due to its connection through the dirty
region and the pleats. Thus the differential force will tend to
force the lower endcap 55 downward slightly, keeping the filter
element in tension, which is an acceptable condition to a pleated
paper filter.
[0047] FIG. 8 shows additional detail of the main seal between the
cover 26 and the housing 21 which prevents fluid in the housing
from exiting the housing. As seen, it is an axially compressed seal
102 and is compressed between the shoulder 58 on the cover and the
similar shoulder 59 on the housing. The lid has female threads 140
which mate with male threads 142 on the housing. As best shown in
FIG. 8 the lid 26 has a long mating section 143 below the female
threads 140 which have a close fit between the outside diameter of
the housing male threads 142 and the inside diameter of the mating
section on the lid. By arranging the structure in this way, the lid
automatically becomes aligned with the housing 21 and it forces the
lid 26 to be threaded correctly and avoids cross threading. Large
diameter threads are prone to cross threading, and the elongated
section where the lid first has a smooth section which fits over
the threads in the housing, before the respective housing threads
are mated, helps to prevent this from occurring.
[0048] A significant feature of the invention is the fact that the
upper and lower seals 102, 56 on the cartridge are attached to the
cartridge itself. Thus they are placed in their proper location by
the manufacturer. Because of the positive snap fit of the gaskets,
they are very difficult to remove, and thus the gaskets are in
their proper place when the cartridge is dropped into the housing.
This feature makes the changing of cartridges for the filtering
system almost full proof. The mechanic does not require any
knowledge as to where to place loose gaskets in the system, because
there are no loose gaskets. This makes changing of the cartridges
fast, easy, avoids errors, and is almost as simple as changing a
spin-on canister.
[0049] Since the main seal between the housing and the lid is an
axial seal 102, the lid 26 is easy to spin on and off. In addition,
it is only necessary to tighten the lid hand tight. If the main
seal were a radial seal, the lid tightening would require a wrench
and additional effort. With respect to user convenience, this is a
significant positive feature.
[0050] When considering the universality of the housing and filter
arrangement, a keying system which associates the particular type
of filter with a particular housing can also be an important
feature. For example, in the ganged situation of FIG. 4, the two
filters in the two parallel housings might have slightly different
characteristics. In other ganged situations, where the filters are
running individually but not in parallel, it will be typical to
have different filters in adjacent identical housings. A keying
system which prevents the installation of the wrong filter would be
of material benefit.
[0051] FIGS. 11 and 12 illustrates a keying feature which can be
used in the practice of the present invention. The inside of the
upper endcap 54 (see FIG. 12) is provided with a plurality of key
positions, best illustrated in FIG. 11. It will be seen that at a
given radius from the center of the endcap 54, a plurality of key
positions 160 are provided. The illustrated embodiment includes
eight key positions in a single ring. More or fewer key positions
per ring, as well as additional rings can also be provided, but it
is believed that the eight key positions, which can provide the
sixteen possibilities illustrated in FIG. 11, is adequate for most
applications.
[0052] Referring primarily to FIG. 12, it will be seen that a
single key 162 is provided on the underside of the illustrated
endcap in a given position. While only a single key is shown in
FIG. 12, as contrasted with the three keys of FIG. 11 it is
believed that the single key 162 will adequately illustrate the
invention without overcomplicating the drawings. The key 162 is in
a fixed angular position with respect to the key circle 163 (the
circle in which the keys are located). The key 162 projects into
the internal bore of the filter element 53. FIG. 12 shows a portion
of the housing centertube 164 having a top surface 165 which is
substantially solid except for a key opening 166. The upper surface
165 of the centertube 164 has a plurality of key positions in a key
circle 167 in the same pattern as illustrated in FIG. 11. However,
instead of projections 162, the keys in the upper surface 165 are
apertures to receive the projections. FIG. 12 shows a single
aperture 166 positioned in the key circle 167 to engage the single
projection 162 positioned in the key circle 163. Thus, when the
filter is installed in the housing, the keys 162 will align and
allow the filter to reach the seated position, allowing the cover
26 to be placed on the housing and operation to continue. If the
wrong filter inserted, the filter will not seat, and the user will
be incapable of completing assembly.
[0053] This feature is particularly significant when using a
universal housing as illustrated in this application. For example,
two housings might be used side-by-side to provide a primary and a
secondary fuel filter system. Both housings would be of the same
diameter and height, but would require different filter cartridges.
The keys will prevent the cartridges for one of the housings from
being installed incorrectly in the other housing. It would be a
simple matter to have several different key configurations to suit
various applications and indeed various customers.
[0054] A further significant feature of the invention is the
plugged filter indicator 48 (see FIG. 1). A detailed
cross-sectional view of the plugged filter indicator is shown in
FIG. 9. The indicator has a button 180 at the top which is spring
loaded by way of a spring 182. A magnet 184 is fit within the top
end of a piston 185 which rides in a cylinder 186. The cylinder 186
is ported to the high pressure region 51 of the filter via a
conduit 187, and to the low pressure region 52 of the filter
housing via a conduit 188. As such, the differential pressure
across the filter is also applied across the piston 185, with the
high pressure side on top. A calibrated spring 190 is arranged
between the body 191 of the housing and a cavity 192 within the
piston 185. Thus the piston 185 is normally biased to the upward
position, with the magnet 184 very near a thin wall 195 which
separate the magnet 184 from an armature 196 in the button 180.
When they are closely positioned, the magnet attracts the armature
196 and keeps the button 180 withdrawn into its associated housing.
However, when the differential pressure across the filters build up
to a level determined by the calibration of the spring 190, the
piston 185 is driven downwardly, separating the magnet 184 from the
armature 196. The button 180 is then released and remains in the
upward position, even if the piston 185 again returns to its top
position. To reset the plugged filter indicator, it is necessary to
manually depress the button 180 to re-latch it to the magnet
184.
[0055] The plugged filter indicator is thus easily ported into the
universal housing, is highly reliable and does not introduce
complications to the overall structure. In addition, it is
relatively economical and has very little possibility of creating
leaks in the system or otherwise deleteriously affecting the system
operation. The calibration spring 190 can also be changed for
different applications. For example, a relatively light spring
would be used in fuel applications where the differential does not
get much higher than say five to seven inches of mercury. When the
housing is set up for a lubrication application or hydraulic
application, heavier springs are used which would change the set
point to somewhere in the range between 15 to 50 psi. This ready
ability to alter the uncomplicated plugged filter indicator is
believed to be a significant advance over the prior art.
[0056] It is emphasized that the filter cartridge to be used with
this system is an environmentally friendly filter made up of
elements which can all be incinerated. FIG. 13, for review, shows,
in elevation, one form of that filter. FIGS. 3 and 13 illustrate
the filter cartridge to include upper endcap 54, lower endcap 55
having a filter element 53 supported therebetween. The filter
element is potted into channels in the respective endcaps using
conventional potting techniques. The lower radial seal gasket 56 is
set in a groove 56a in the lower endcap. Similarly, the axial seal
gasket 102 is set in a groove 102a in the upper endcap 54. The
pressure equalization port 122 is also illustrated. It will thus be
apparent that once it is spent, filters such as that shown in FIG.
13 can be removed from the housing, collected and incinerated, and
will leave very little residue.
[0057] All references, including publications, patent applications,
and patents, cited herein are hereby incorporated by reference to
the same extent as if each reference were individually and
specifically indicated to be incorporated by reference and were set
forth in its entirety herein.
[0058] The use of the terms "a" and "an" and "the" and similar
referents in the context of describing the invention (especially in
the context of the following claims) are to be construed to cover
both the singular and the plural, unless otherwise indicated herein
or clearly contradicted by context. The terms "comprising,"
"having," "including," and "containing" are to be construed as
open-ended terms (i.e., meaning "including, but not limited to,")
unless otherwise noted. Recitation of ranges of values herein are
merely intended to serve as a shorthand method of referring
individually to each separate value falling within the range,
unless otherwise indicated herein, and each separate value is
incorporated into the specification as if it were individually
recited herein. All methods described herein can be performed in
any suitable order unless otherwise indicated herein or otherwise
clearly contradicted by context. The use of any and all examples,
or exemplary language (e.g., "such as") provided herein, is
intended merely to better illuminate the invention and does not
pose a limitation on the scope of the invention unless otherwise
claimed. No language in the specification should be construed as
indicating any non-claimed element as essential to the practice of
the invention.
[0059] Preferred embodiments of this invention are described
herein, including the best mode known to the inventors for carrying
out the invention. Variations of those preferred embodiments may
become apparent to those of ordinary skill in the art upon reading
the foregoing description. The inventors expect skilled artisans to
employ such variations as appropriate, and the inventors intend for
the invention to be practiced otherwise than as specifically
described herein. Accordingly, this invention includes all
modifications and equivalents of the subject matter recited in the
claims appended hereto as permitted by applicable law. Moreover,
any combination of the above-described elements in all possible
variations thereof is encompassed by the invention unless otherwise
indicated herein or otherwise clearly contradicted by context.
* * * * *