U.S. patent application number 09/848125 was filed with the patent office on 2001-09-13 for reverse flow air filter arrangement.
This patent application is currently assigned to Donaldson Company, Inc.. Invention is credited to Bartels, Dolan, Crenshaw, Bruce, Engel, Donald Francis, Hacker, John, Harold, Don.
Application Number | 20010020419 09/848125 |
Document ID | / |
Family ID | 27407614 |
Filed Date | 2001-09-13 |
United States Patent
Application |
20010020419 |
Kind Code |
A1 |
Engel, Donald Francis ; et
al. |
September 13, 2001 |
Reverse flow air filter arrangement
Abstract
A reverse flow air filter arrangement is provided. The
arrangement includes a filter element having first and second end
caps, the second end cap having a central drainage aperture. A
funnel shape on an interior surface of second end cap is used to
direct moisture flow to the drainage aperture. The arrangement
includes a housing in which the filter element is positioned,
operatively, during use. Certain features in the housing facilitate
moisture withdrawal from the filter element while also inhibiting
interference with sealing between the filter element and the
housing.
Inventors: |
Engel, Donald Francis;
(Prior Lake, MN) ; Bartels, Dolan; (Cresco,
IA) ; Hacker, John; (Bloomington, MN) ;
Crenshaw, Bruce; (Indianapolis, IN) ; Harold,
Don; (Prior Lake, MN) |
Correspondence
Address: |
MERCHANT & GOULD
P O BOX 2903
MINNEAPOLIS
MN
55402-0903
US
|
Assignee: |
Donaldson Company, Inc.
Minneapolis
MN
|
Family ID: |
27407614 |
Appl. No.: |
09/848125 |
Filed: |
May 3, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09848125 |
May 3, 2001 |
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09467405 |
Dec 20, 1999 |
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6258145 |
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09467405 |
Dec 20, 1999 |
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09198846 |
Nov 24, 1998 |
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6004366 |
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09198846 |
Nov 24, 1998 |
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08884205 |
Jun 27, 1997 |
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5938804 |
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08884205 |
Jun 27, 1997 |
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08742244 |
Oct 31, 1996 |
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5690712 |
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08742244 |
Oct 31, 1996 |
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08344371 |
Nov 23, 1994 |
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5613992 |
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Current U.S.
Class: |
96/189 ; 55/428;
55/476; 55/498; 55/502 |
Current CPC
Class: |
B01D 46/2411 20130101;
B01D 46/0041 20130101; B01D 2265/06 20130101; B01D 46/0002
20130101; B01D 2271/022 20130101; B01D 2271/027 20130101; B01D
46/0043 20130101; B01D 46/2414 20130101; B01D 46/24 20130101; B01D
46/0031 20130101 |
Class at
Publication: |
96/189 ; 55/428;
55/476; 55/498; 55/502 |
International
Class: |
B01D 046/00 |
Claims
What is claimed is:
1. An air filter element comprising: (a) first and second,
opposite, end caps; (b) filter media; (c) an inner liner defining
an open filter interior; (d) said first end cap having an air inlet
opening therein; (e) said second end cap having: (i) a central
drainage aperture extending therethrough; and, (ii) an interior
surface constructed and arranged to direct moisture on said second
end cap interior surface to said central drainage aperture.
2. An air filter element according to claim 1 wherein: (a) said
second end cap comprises a composite including: (i) an inner insert
having a first, inner, surface defining said second cap interior
surface and an opposite, second, outer, surface; said inner insert
having a central aperture extending therethrough; and, (ii) a
compressible polymeric material covering at least a portion of said
outer surface of said insert; said inner liner being embedded in
said compressible polymeric material; said polymeric material
having a central aperture therein aligned with said aperture in
said inner insert, to form said central drainage aperture.
3. A filter element according to claim 2 wherein: (a) said
compressible polymeric material comprises a material having an as
molded density within the range of 14-22 pounds per cubic foot.
4. A filter element according to claim 3 wherein: (a) said
compressible polymeric material comprises polyurethane foam.
5. A filter element according to claim 2 wherein: (a) said inner
insert includes a circular trough in said outer surface positioned
to extend around said insert central aperture.
6. A filter element according to claim 5 wherein: (a) said insert
trough is semi-circular in cross-section.
7. A filter element according to claim 2 wherein: (a) said inner
insert includes a plurality of free rise apertures therein; and,
(b) a portion of said compressible polymeric material projects
through said free rise apertures.
8. A filter element according to claim 7 wherein: (a) each of said
free rise apertures is positioned between an associated pair of
ridges extending outwardly from said insert first surface.
9. A filter element according to claim 8 wherein: (a) each pair of
wall projections comprises first and second, spaced, walls
extending along a direction from an outer perimeter of said inner
insert toward said central drainage aperture.
10. A filter element according to claim 8 wherein: (a) said inner
insert includes a plurality of pairs of wall projections comprising
a first set of pairs and a second set of pairs; (i) each pair of
said second set of pairs being shorter, in longitudinal extension
toward said central drainage aperture, than each pair of said first
set of pairs.
11. A filter element according to claim 10 wherein: (a) each pair
of said first set of pairs is spaced from each adjacent pair of
said first set by a member of said second set of pairs; and, (b)
each pair of said second set of pairs is spaced from each adjacent
pair of said second set by a member of said first set of pairs.
12. A filter element according to claim 11 wherein: (a) said first
set of pairs consists of four pairs of walls; (b) said second set
of pairs consists of four pairs of walls; and, (c) each pair of
walls is evenly, radially, spaced on said inner insert first
surface and around said central drainage aperture.
13. A filter element according to claim 12 wherein: (a) said inner
insert has an outer periphery with a plurality of spaced legs
extending outwardly therefrom: (i) said spaced legs projecting
axially outwardly from said inner insert in a direction from said
inner insert second side.
14. A filter element according to claim 13 wherein: (a) each one of
said spaced legs has a radially directed foot thereon; each
radially directed foot extending away from an associated leg by a
distance of at least 0.375 inches.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation-in-part
application of U.S. Ser. No. 08/742,244, filed Oct. 31, 1996. U.S.
Ser. No. 08/742,244 was a divisional of U.S. Ser. No. 08/344,371,
filed Nov. 23, 1994. The complete disclosure of application U.S.
Ser. No. 08/742,244 is incorporated herein by reference.
Application Ser. No. 08/344,371 issued on Mar. 25, 1997 as U.S.
Pat. No. 5,613,992. The complete disclosures of U.S. Pat. No.
5,613,992 and the application which issued as the '992 patent are
also incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to reverse flow air cleaner
arrangements. That is, the invention concerns air cleaner
arrangements wherein filtering flow is in a direction with the
"clean" side of the air filter being around an exterior thereof,
and the "dirty" side of the air filter being along an interior
thereof. The invention particularly concerns such air cleaner
arrangements having drainage systems for water accumulating in an
interior of associated air filter elements. The invention also
concerns provision of preferred components, such as air filter
elements, for use with such arrangements; and, to methods involving
the use of such arrangements.
BACKGROUND OF THE INVENTION
[0003] In general, air cleaner arrangements include a housing and
an air filter element. The housing is configured such that air is
directed through the air filter element, for filtering. Various
geometric configurations of the air cleaner housing, the air filter
element, and related seal arrangements are used to effect this.
[0004] Many air cleaner arrangements include generally cylindrical
air filter elements. Such elements typically include filter media
arranged in a cylindrical pattern, with end caps. Seal arrangements
are used either on or in conjunction with the end caps, to provide
appropriate sealing with the housing or other portions of the air
cleaner, and to control the direction of air flow.
[0005] Reverse air flow air cleaner arrangements are generally
those in which air is directed to an interior of the air filter
element before it is filtered, and the air is filtered as it passes
through the air filter element from the interior to the exterior.
If the air filter element is cylindrical, this means that the
unfiltered air is directed into the interior of the cylinder, and
then through the filter media, to an exterior, during filtering.
Material entrained in the air directed into the air filter, then,
is left along an interior of the cylindrical filter media.
[0006] Consider, for example, a reverse flow air cleaner
arrangement, having a cylindrical air filter element, utilized on
an over the highway truck. Air directed into the interior of the
cylindrical element may include dust, leaves, large particulates,
and even moisture entrained therein. This material will tend to
build up in the interior of the air filter element, in time. If the
water depth inside the air filter becomes significant, the water,
alone or with fine particulates or salt in suspension, can permeate
the filter media. This has the potential to damage engine
components. It would be preferred that arrangements be provided to
drain the water from the interior of the filter element.
[0007] In those arrangements wherein the filter element is
operationally oriented such that the longitudinal axis of the
cylindrical air filter is substantially vertical, drainage
arrangements involving drainage apertures in one of the end caps
have been used. In general, these have involved offset (from a
central location) apertures in one end cap, and unless the air
filter element is oriented nearly perfectly vertically, drainage is
inefficient. Also, in such arrangements debris can sometimes
collect along interior surfaces of the housing when the arrangement
is opened and the element is removed; and, unless the housing is
thoroughly cleaned before the element is reinserted into the
housing, the debris can interfere with attainment of a good seal at
critical locations.
SUMMARY OF THE DISCLOSURE of U.S. Ser. No. 08/742,244
[0008] According to the disclosure of U.S. Ser. No. 08/742,244, an
air filter arrangement is provided. The air filter arrangement
includes a housing and an air filter element having first and
second opposite end caps, filter media and an open filter interior.
The first end cap has an air inlet opening therein, for air to be
passed into the arrangement to be filtered. The second end cap has
a central drainage aperture and an interior surface constructed and
arranged to funnel moisture that collects on the second end cap
interior surface to the central drainage aperture, and outwardly
from the filter element. The central drainage aperture is
preferably positioned at a center of the second end cap, with a
longitudinal axis of the air filter element passing therethrough.
The air filter arrangement also includes an air flow direction
arrangement constructed and arranged to direct air flow into the
housing, into the open filter interior, through the filter media
for filtering and then outwardly from the housing, as filtered air.
The air flow direction arrangement generally comprises various
features of the housing, seals and filter element.
[0009] Preferably, the interior surface of the second end cap is
circular. In certain embodiments it includes a plurality of
radially directed troughs which terminate in the central drainage
aperture. The troughs can be used to help funnel and direct
moisture collected on an interior surface of the air filter element
in use (i.e., "when operationally" or "operatively" assembled).
[0010] In certain preferred arrangements, according to the U.S.
Ser. No. 08/742,244 disclosure, the second end cap includes an
outer annular compressible portion and the housing includes an
annular sealing surface against which the second end cap outer
annular compressible portion is sealed, when the air filter
arrangement is operatively assembled for use. Such a seal is
referred to herein as a peripheral or annular radial seal, around
the second end cap. That is, in this context the term "annular"
refers to a sealing portion around the outside of the end cap,
which seals under radial compression.
[0011] In a preferred embodiment, according to the U.S. Ser. No.
08/742,244 disclosure, the housing includes a base having a
central, preferably recessed, pan and a sealing bead
circumferentially positioned around the central recessed pan. A
drainage aperture is provided in the central pan, so that water
collected in the pan can be removed from the housing. With such an
arrangement, preferably the second end cap is constructed and
arranged to form a secondary seal with the sealing bead in the
base, when the air filter element is operatively positioned within
the housing. Preferably the manner of engagement with the seal bead
is by provision of a mating "trough" in the second end cap outer
surface.
[0012] According to the U.S. Ser. No. 08/742,244 disclosure,
preferably the second end cap outer surface has an outer edge or
lip; and, the second end cap outer surface is recessed (or
depressed) in extension between the outer edge and the trough which
engages the sealing bead and the base. In this manner, a preferred
gap or space is provided between the filter element second end cap,
and the housing base, in the region between the sealing bead of the
base and an outer peripheral area of the base. A space in this
location accommodates debris that may collect in the housing,
without interference with the seal between the second end cap and
the housing. This is facilitated by those arrangements involving
provision of the seal along an annular portion of the end cap, as a
radial seal, rather than as an end or axial seal.
[0013] According to the U.S. Ser. No. 08/742,244 disclosure,
preferably the second end cap outer surface is configured to
provide a funnel surface having a declination angle of at least
about 10, and preferably 10 to 30, in the region of extension
between the outer edge of the second end cap and the portion of the
end cap which engages the seal bead in the base.
[0014] In preferred arrangements, according to the U.S. Ser. No.
08/742,244 disclosure, an evacuation valve is mounted in the
drainage aperture of the recessed pan in the base. This provides
for a preferred, controlled, drainage of moisture from the
system.
[0015] In preferred embodiments, according to the U.S. Ser. No.
08/742,244 disclosure, a soft polymeric material is utilized for
the first and second end caps. Preferably each of the polymeric end
caps comprise polyurethane. For the end caps, a polyurethane foam
material having an "as molded" density of about 14-22 lbs per
ft.sup.3 will be preferred (most preferably about 18.4). In some
embodiments, the same material can be utilized for both end
caps.
[0016] In preferred constructions, according to the U.S. Ser. No.
08/742,244 disclosure, an air inlet tube is provided in the
housing, which is configured to generate a radial seal with the
first end cap of the filter element.
[0017] In an alternate embodiment, described in the U.S. Ser. No.
08/742,244 disclosure, an arrangement having a sheet metal end cap
as the second end cap is provided. This arrangement is preferably
axially sealed, by provision of a primary seal gasket axially
compressed between the second end cap and the base, when the air
filter arrangement is operationally assembled. A secondary gasket
can also be provided in such arrangements between a selected
portion of the second end cap and the housing base.
[0018] According to the U.S. Ser. No. 08/742,244 disclosure, a
preferred filter element is provided. The preferred filter element
comprises a generally cylindrical extension of filter media. The
filter media may be, for example, a pleated paper filter media.
Preferably, an inner support liner and an outer support liner are
provided, for the cylindrical extension of filter media. Preferably
the arrangement has first and second end caps, the first end cap
including an air inlet opening therein. The second end cap
preferably has a central drainage aperture and an interior surface
constructed and arranged to funnel moisture, collected on the
interior surface of the second end cap, to the central drainage
aperture. The central drainage aperture is preferably located at an
approximate center of the end cap, on a longitudinal axis of the
cylindrical extension of filter media. A preferred configuration
for the interior surface of the second end cap, is as an interior
of a funnel. In some embodiments, the second end cap interior
surface includes a plurality of radially directed troughs therein,
which terminate at the central drainage aperture.
[0019] Other preferred features for the preferred air filter
element described in the U.S. Ser. No. 08/742,244 disclosure
include: a circular sealing trough on an outer surface of the
second end cap; and, a recess between an outer edge of the end cap
outer surface and the circular trough. Also, a compressible region
providing for a radial seal along an annular portion of the second
end cap is preferred.
[0020] According to the U.S. Ser. No. 08/742,244 disclosure, a
method of operating a reverse flow air filter arrangement is
provided. In general, the method comprises collecting moisture
within the filter element and draining the moisture from the filter
element through a central aperture in the end cap, by funneling the
moisture to the central aperture.
SUMMARY OF THE PRESENT DISCLOSURE
[0021] According to the portion of the present specification which
comprises added disclosure relating to FIGS. 9-14, the end cap
which includes the drainage aperture therein, is provided in a
preferred composite structure. The composite results from an outer
portion comprising a soft, compressible, polymeric material; and,
an inner "pre-form" or insert, which becomes positioned between the
polymeric material and the inner liner, during molding. The insert
has preferred inner surface characteristics, to accomplish
desirable flow of liquid to the drainage aperture, and outwardly
from an interior of the filter element. In addition, it has
preferred features to facilitate molding using a free rise
technique.
[0022] The preferred "pre-form" or insert also has depending legs
with outwardly projecting feet. The legs and feet operate,
cooperatively, as a mold stand-off for media. An underside of each
foot has a bead thereon, to facilitate this.
[0023] Further features and advantages from the preferred inserts
and "pre-forms" described herein, as well as techniques for use,
will be apparent from the more detailed description below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a side elevational view of an air cleaner
arrangement according to the present invention.
[0025] FIG. 2 is a top plan view of the arrangement shown in FIG.
1.
[0026] FIG. 3 is an exploded plan view of the arrangement shown in
FIG. 1.
[0027] FIG. 4 is an enlarged fragmentary side cross-sectional view
of a portion of the arrangement shown in FIG. 1; FIG. 4 being
generally taken along line 4-4, FIG. 1.
[0028] FIG. 5 is a fragmentary cross-sectional view of a portion of
the arrangement shown in FIG. 1; FIG. 5 generally being taken along
line 5-5, FIG. 1.
[0029] FIG. 6 is a fragmentary exploded view of a portion of the
arrangement shown in FIG. 5.
[0030] FIG. 7 is a fragmentary top plan view of a portion of the
arrangement shown in FIG. 6.
[0031] FIG. 8 is a fragmentary cross-sectional view of an alternate
embodiment to that shown in FIGS. 1-7.
[0032] FIG. 9 is a fragmentary cross-sectional view of a second
alternate embodiment of the present invention, taken from a point
of view analogous to that used for FIG. 5.
[0033] FIG. 10 is a top plan view of a component used in the
alternate embodiment of FIG. 9.
[0034] FIG. 11 is a cross-sectional view of the component depicted
in FIG. 10, taken along line 11-11 thereof.
[0035] FIG. 12 is a schematic representation of a method of
assembling the embodiment of FIG. 9.
[0036] FIG. 13 is a fragmentary schematic representation of a
cross-section of a mold configuration usable to generate the
assembly of FIG. 9.
[0037] FIG. 14 is a bottom plan view of a filter element including
the component of FIGS. 10 and 11 therein.
[0038] FIG. 15 is a schematic cross-sectional view depicting the
component of FIG. 10 positioned in the mold of FIG. 13.
[0039] FIG. 16 is an enlarged view of one of the legs of the
component depicted in FIG. 11.
DETAILED DESCRIPTION
[0040] Disclosure of U.S. Ser. No. 08/742,244 and Its Parent U.S.
Ser. No. 08/344,371
[0041] The reference numeral 1, FIG. 1, generally designates an air
cleaner assembly according to the disclosure of Ser. No.
08/742,244. FIG. 1 is a side elevational view of air cleaner
assembly 1. In the Figure, housing 2 is depicted generally. The
housing 2 includes an inlet construction 3 and a filter element
receiver or can 4. Can 4 includes outlet 7. In use, air to be
filtered passes through inlet construction 3, and is directed to an
interior of can 4. Within can 4, the air is directed through a
filter element, not viewable in FIG. 1. After being filtered by the
filter element, the air passes outwardly through outlet 7 and is
directed to the air intake of the engine, not shown. Herein, the
term "air flow direction arrangement" is used to generally refer to
those features of an air filter arrangement which direct air flow
in the preferred manner or along a preferred path. The term may
refer to a variety of features, and typically refers to internal
configurations of the housing and filter element, as well as the
various seals.
[0042] Still referring to FIG. 1, inlet construction 3 is mounted
on can 4, and is secured thereto by bolts 8 and nuts 9. Access to
the interior of can 4, and a filter element positioned therein, is
obtained by loosening bolts 8 and separating inlet construction 3
from can 4.
[0043] For the particular construction shown, inlet construction 3
includes an upper dome 12, perforated air inlet screen 13 and an
inlet tube 14 (the inlet tube not being viewable in FIG. 1, but
being shown in FIG. 4 in cross-section).
[0044] Still referring to FIG. 1, can 4 includes a drainage
aperture therein, the drainage aperture not being viewable in FIG.
1, but being shown at reference numeral 18 in FIG. 5. The drainage
aperture is covered by an evacuation valve 19. The evacuation valve
19 may be, for example, as described in U.S. Pat. No. 3,429,108,
the disclosure of which is incorporated herein by reference. In
general, the drainage aperture 18 is positioned in a portion of can
4 which will be, when assembly 1 is operatively installed,
positioned at the bottom of the assembly 1. Thus, water will tend
to collect near aperture 18, and be drained therefrom, in use. This
will be more readily apparent from further descriptions wherein
internal details of air cleaner assembly 1 are presented.
[0045] Referring to FIG. 2, air cleaner assembly 1 includes four
bolts and nuts 9 for securing the inlet construction 3 to the
filter can 4. While the number of bolts used may be varied,
depending on the particular application, it is an advantage of
constructions according to the Ser. No. 08/742,244 disclosure that
filter assemblies as large as about 15 inches in outside diameter
can be reliably secured closed, with as few as about three to five
bolts. Features which facilitate this, will be apparent from
further descriptions.
[0046] An exploded view of air cleaner assembly 1 is depicted in
FIG. 3. In FIG. 3, air cleaner assembly 1 is shown with inlet
construction 3 separated from filter can 4, and with air cleaner
element 21 removed from can 4. For the particular arrangement
shown, air cleaner element 21 is generally cylindrical. Element 21
includes first and second end caps 23 and 24; filter media 25;
inner support 26 (FIG. 4); and, outer support 27. For the
particular embodiment shown, filter media 25 comprises a pleated
paper construction 30. In general, pleated paper construction 30
comprises a cylinder 31 of fluted paper with the flutes running in
a direction longitudinally along, and generally parallel to, a
central axis 33 of the element 21. It will be understood that
alternate filter media constructions could be utilized. In general,
the filter media 25 extends between the end caps 23 and 24. For
assembly 1 depicted, end caps 23 and 24 comprise polymeric material
as described below, in which opposite ends of the filter media 25
are set or potted.
[0047] In FIG. 4 a fragmentary cross-sectional view of air cleaner
assembly 1 is depicted. In FIG. 4, the inlet construction 3 and
portions of air cleaner assembly 1, in association therewith, are
depicted.
[0048] In general, the filter media 25 is positioned between inner
support 26 and outer support 27. Each support generally comprises a
tubular or cylindrical extension of perforated metal or expanded
metal, opposite ends of which are also set in, or potted in, end
caps 23 and 24.
[0049] In general, end cap 23 is open and end cap 24 is closed.
That is, end cap 23 includes a large inlet aperture 28 (FIG. 4)
therein, for introduction of air to be filtered into filter element
interior 35. End cap 24, on the other hand, is generally closed,
but for a drainage aperture extending therethrough as described
below.
[0050] Still referring to FIG. 4, it can be seen that inlet
construction 3 includes inlet tube 14. When assembled, inlet tube
14 extends into aperture 28 in end cap 23. At least in this
location, end cap 23 is preferably formed of a soft compressible
material. When inlet tube 14 is not inserted into aperture 28, at
least a portion of aperture 28 in its uncompressed state will
generally have an inside diameter slightly larger than an outside
diameter of section 39 of inlet tube 14; i.e., the portion of tube
14 which engages end cap 23 when arrangement 1 is operatively
assembled. Thus, when inlet tube 14 is inserted through aperture
28, end cap material in region 40 will be compressed. In this
manner a seal is formed at region 41. Such seals are described, for
example, in conjunction with air cleaner assemblies in U.S. Patent
B2 4,720,292, the disclosure of which are incorporated herein by
reference. It is noted that the arrangement of U.S. Pat. 4,720,282
is not necessarily a reverse flow arrangement; however, the
principles relating to the formation of the seal are basically the
same. Such seals-are sometimes referred to as "radial" or
"radial-type" seals, since the forces maintaining sealing are
directed radially around a central longitudinal axis 33 (FIG. 3) of
the tube and element, rather than co-extensively or coaxially
therewith. For the particular arrangement shown in FIGS. 1-7,
material at region 40 is compressed between and against both inlet
tube 14 and inner support 26; that is, inner support 26 is set
sufficiently deeply into end cap 23 that a portion of it is
positioned behind compressible region 40, to provide support. Thus,
a good seal is effected. The shape of aperture 28 in region 41 will
preferably be as a ribbed or stepped funnel (or tapered), to
facilitate engagement. Such a ribbed arrangement is shown in U.S.
Pat. No. 5,238,474, incorporated herein by reference. In U.S. Pat
No. 4,720,292 a similarly tapered surface without ribs is shown.
Preferably, three equally sized steps from a region of diameter
about the same as the inlet tube O.D. are used, with the amount of
total compression of the smallest diameter rib (i.e., region of
most compression) being about 21.4% (20%.+-.3%). The size of each
step will depend in part on the diameter of the inlet tube. In
general, for an element used with an inlet tube having an O.D. of
175-200 mm, a total compression thereacross of 2.7 mm (or 1.35 mm
for any location since any location compresses about one-half of
the total compression) for the smallest rib would be used.
[0051] It will be understood, then, that for the arrangement shown
in FIGS. 1-7, seal 41 prevents air directed into filter interior 35
through inlet tube 14 from bypassing filter media 25 and getting
into clean air plenum 44. In general, the various portions of the
arrangement 4 cooperate as an air flow direction arrangement to
direct air flow: into the housing, into the filter interior,
through the filter media and outwardly from the housing.
[0052] Another point of potential leakage of unfiltered air into
clean air plenum 44 is presented by the location whereat inlet
construction 3 engages filter can 4. This region is located
generally at 50; i.e., where bolts 8 secure inlet construction 3 to
filter can 4. At region 50, inlet construction 3 is provided with
an outwardly extending flange 52; and, can 4 is provided with an
outwardly extending flange 53. Seal ring 54 is provided in
extension around can 4, between flanges 52 and 53. Seal ring 54 is
positioned at a location between bolts 8 and filter element 21.
When bolts 8 are tightened, seal ring 54 will be compressed between
flanges 52 and 53, i.e., at a location between inlet construction 3
and filter can 4, providing a seal. Thus, air leakage into plenum
44, by passage between portions of can 4 and inlet construction 3
is inhibited. Filter ring 54 may be a conventional O-ring type
gasket.
[0053] Attention is now directed to FIG. 5, which is a
cross-sectional view showing the "bottom half" or "opposite end" of
assembly 1 from the end whereat inlet construction 3 is located.
Referring to FIG. 5, reference numeral 60 generally designates an
end of can wall 61. Within end 60 is positioned a cover or base 63
of can 4. Base 63 is configured in a preferred manner, to
advantage.
[0054] For the particular embodiment shown, base 63 is circular, to
conform to the cross-sectional configuration of can wall 61 at end
60. For the particular embodiment shown, base 63 is also radially
symmetric. That is, the features of base 63 are configured radially
symmetrically about central axis 33. Base 63 includes end flange 65
for engagement with end 60, for example by means of welds.
[0055] Progressing inwardly from flange 65 toward its center 66,
the features of the preferred base 63 depicted are as follows: an
annular circumferential sealing surface 67 is provided; a bend or
corner 68; an end surface 69; a secondary seal bead or ridge 70;
and, a central pan 71. In the center 66 of pan 71, drainage
aperture 18 is provided.
[0056] The arrangement shown in FIGS. 1-7 is configured
preferentially so that when oriented for use, pan 71 is at a
lowermost or recessed location, so that water will drain to pan 71
under gravity influence. As the water drains into pan 71, it will
be drained outwardly from air cleaner assembly 1 through drainage
aperture 18. Particular features described herein are provided, for
a preferred manner of debris collection within assembly 1 and
drainage of collected moisture to aperture 18.
[0057] Still referring to FIG. 5, filter element 21 includes end
cap 24 thereon. End cap 24 is of an appropriate material, and of
appropriate size, so that when it is pushed into and against base
63, an outer circumferential surface 75 of the end cap 24 engages
surface 67 of base 63 in a sealing manner. That is, an annular seal
76 is formed in region 77, circumferentially around end cap 24.
This is facilitated by preferably providing surface 67 in a
cylindrical configuration extending generally parallel to axis 33.
The seal prevents unfiltered air from reaching clean air plenum 44.
As a result of the circumferential seal, sealing against flow of
air is not required between any other portions of filter element 21
and base 63. A secondary seal 80, described herein below, is
provided, however, between end cap 24 and base 63. The secondary
seal 80 is generally provided to inhibit movement of debris or
water into region 81, between element 21 and base 63, rather than
to necessarily prevent flow of air therebetween. Thus, while seal
76 should be in a form sufficient to withstand a pressure
differential thereacross of up to about 40 inches of H.sub.2O,
secondary seal 80 will generally be sufficient if it can maintain
at pressure differential thereacross of up to about 2 inches (and
typically only up to about 2-4 inches) of H.sub.2O.
[0058] Still referring to FIG. 5, end cap 24 includes a circular
recess or trough 85 therein. Trough 85 is sized and configured to
receive and sealingly engage bead 70. Trough 85 should be sized,
relative to bead 70, such that when element 21 is pressed against
base 63, bead 70 is pushed into trough 85 to form a seal therewith,
capable of holding a pressure differential of up to about 2-4
inches of H.sub.2O. This could be readily accomplished by forming
the related region 86 of end cap 24 of an appropriately soft
compressible polymeric material into which rigid bead 70 can be
pressed, for engagement.
[0059] Referring to FIGS. 5 and 6, it is noted that for the
preferred embodiment depicted surface 90 of end cap 24 is recessed
from outer edge 91 to region 92, so that a space between surface 90
and end surface 69 is provided, when filter element 21 is
operatively positioned within can 4. The amount of recess can be
varied, depending upon the size of the arrangement. In general, an
angle of inclination from edge 91 to region 92 on the order of
about 1.degree. to 3.degree. will be sufficient.
[0060] Advantages which result from this inclination, will be
apparent from further descriptions herein below. In general, the
space between surface 90 and end surface 69 ensures that there will
not be interference with easy formation of the annular, radial,
seal.
[0061] Still referring to FIGS. 5 and 6, internal surface 94 of end
cap 24 is configured to slope downwardly, when the assembly 1 is
oriented as shown in FIGS. 5 and 6, in extension from outer region
95 toward central aperture 96. Preferably, internal surface 95 is
conical or funnel shaped in this region. Thus, any water which
collects on internal surface 94 will tend to flow toward central
aperture 96 and therethrough, into recessed pan 71. In some
embodiments, recessed radial troughs extending outwardly and
upwardly from central aperture 96 can be used to facilitate this
flow. Such an arrangement is shown, for example, in FIG. 7 (a top
plan view of element 21) wherein four evenly (radially) spaced,
recessed, troughs 99 are depicted. It will be understood that each
of troughs 99 generally inclines downwardly as it extends from
region 95 toward central aperture 96, to facilitate collection of
water within interior 35 and direction of the collected water to
central aperture 96. An advantage to troughs 99 is that should a
leaf or other large particulate material become positioned over
central aperture 96, water can still flow into and through the
aperture 96 by means of the troughs 99, since the troughs 99 can
generally direct water flow underneath debris collected on top of
internal surface 94.
[0062] Numerous advantages result from the preferred features
described. As assembly 1 is used for a filtering operation, air
will generally flow through inlet tube 14 into interior 35,
carrying within it moisture and/or debris. The moisture and debris
will tend to collect within interior 35, on internal surface 94 of
end cap 24, since arrangement 1 will generally be configured with
end cap 24 positioned beneath inlet tube 14. Water collecting on
internal surface 95 will generally be directed toward central
aperture 96, for drainage into recessed pan 71 and eventually
drainage outwardly from assembly 1 through drainage aperture 18.
Evacuation valve 19, if used, will facilitate this.
[0063] Because sealing between end cap 24 and housing 2 is
positioned along annular circular sealing surface 67, i.e., at
region 77, the critical sealing is not located at a surface where
debris is likely to be spread or collect, as element 21 is removed
from and replaced into housing 2, during typical maintenance
operations.
[0064] Because surface 90 is recessed from end surface 69, in
extension between edge 91 and region 92, any debris which may
spread along end surface 69 during operations involving removal and
insertion of filter elements into housing 2, will not likely
interfere with sufficient insertion of the element 21 into can 4
for the development of a good seal at region 77. That is, some
debris buildup along the bottom of base 63 is well tolerated.
[0065] Also, secondary seal 80 will inhibit the likelihood of
debris or moisture moving from pan 71 into surface 69, or region
77. This will also help facilitate removal of moisture from
assembly 1, since the moisture will tend to concentrate near
drainage aperture 18.
[0066] In FIG. 6, the arrangement of FIG. 5 is shown exploded. From
this, a preferred configuration for surface 75, relative to
circular (annular) sealing surface 67 will be understood. In
particular, surface 75 includes steps 101, 102 and 103, with
extensions 105 and 106 therebetween. Step 103 is approximately the
same diameter as circular sealing surface 67, and facilitates
guidance of air cleaner element 21 into engagement with base 63,
during assembly. Step 102 is preferably slightly larger in diameter
than circular sealing surface 67, and step 101 is preferably
slightly larger in diameter than step 102, to enhance compression
of end cap material in region 77, as element 21 is inserted into
base 63, during assembly. In this manner, a good seal is formed. In
general, for preferred embodiments the actual amount of compression
of the end cap in region or step 102 is 3 mm.+-.1 mm on diameter
(or 1.5 mm at any location). The diameter of step 102 is preferably
about 1.5 mm greater than step 101, and about 3 mm greater than
step 103. The amount of compression in step 102 would preferably be
about 21.4% (20%.+-.3%).
[0067] As indicated, the arrangement described with respect to
FIGS. 1-7 generally utilizes a radial seal engagement in region 77.
Alternate sealing arrangements may be utilized. An example of such
an arrangement is illustrated in the alternate embodiment of FIG.
8.
[0068] In FIG. 8 an alternate application of principles according
to the Ser. No. 08/742,244 disclosure is provided. FIG. 8
illustrates an engagement between an air cleaner assembly base and
a filter element, to provide advantages according to the present
invention, in an arrangement which utilizes an "axial seal" between
the filter element and the housing, at least at this location.
[0069] In general, an axial seal is a seal which is maintained by
forces directed along an axis of the filter element, as opposed to
radial seal arrangements described with respect to FIGS. 1-7 which
use forces directed radially around an axis. Axial seal
arrangements have been widely utilized in filter elements in a
variety of manners. Often a central yoke or axle is provided, along
which forces are directed between the housing in the element. In
other systems a bolt engagement between portions of the housing are
used to compress the element against one end or both ends of the
housing. The 0-ring 54 in the embodiment of FIGS. 1-7, for example,
provides sealing by axial compression.
[0070] FIG. 8 is a fragmentary cross-sectional view of an alternate
air cleaner assembly 115. The air cleaner assembly 115 is also a
reverse flow arrangement. Assembly 115 includes housing 116 and air
filter element 117. An inlet arrangement, not depicted, would be
utilized to direct air flow into interior 118. Air flow would then
be through filter element 117 into clean air plenum 120, and
outwardly through a conventional outlet, not shown, into an air
intake for an engine.
[0071] In FIG. 8 the outer wall of the housing 116 or can, is
generally shown at 121. The housing end or base 123 is configured
to perform functions generally analogous to those for base 63,
FIGS. 1-7.
[0072] Still referring to FIG. 8, filter element 117 has a sheet
metal end cap, such as end cap 125. The filter element 117 includes
filter media 126 potted within the end cap 125 (the opposite end
cap not being shown in FIG. 8). Element 117 includes inner and
outer liners 127 and 128 respectively.
[0073] Sealing between element 117 and base 123, against air flow
therebetween, is provided by gasket 130. That is, an appropriate
mechanism to apply axial forces in the direction of arrow 131
against element 117 should be provided, to compress gasket 130
between end cap 125 and base 123 and form a seal. This can be
accomplished with bolts used to drive an end cover or inlet
construction against an opposite end of element 117. Preferably
appropriate sizes and configurations of the element 117, base 123
and gasket 130 are selected, so that the seal of gasket 130 will be
sufficient to hold a pressure differential at least about 40 inches
of H.sub.2O thereacross. In this manner, unfiltered air in region
132 is prevented from reaching clean air plenum 120, in use.
[0074] In general, the features of the preferred base 123 depicted
are as follows. Base 123 is radially symmetric and includes outer
flange 135, for securement to can wall 121, such as by welding.
Base or recess area 136 is provided for a receipt of gasket 130
therein, during sealing. This is accommodated by recessed area 136
forming a trough 137. Region 138, of base 123, is raised above
trough 137, and provides a raised surface 139 for provision of a
secondary seal, as described below. Base 123 then defines pan 145,
by downwardly extending or declining wall 146, towards a recessed
central aperture 147.
[0075] With respect to the filter element, end cap 125 includes a
downwardly slanted surface 149 toward central pan 150 having
drainage aperture 151 therein.
[0076] A secondary seal between end cap 125 and surface 139 is
provided by secondary seal gasket 155. This gasket 155 is intended
to inhibit the migration of moisture and debris from recessed pan
145 into region 137, whereat it could interfere with seal gasket
130. Secondary gasket 155 need only provide a seal sufficient to
inhibit substantial migration of moisture and debris, and does not
need to be a primary air seal. Thus, gasket 155 need only be
compressed sufficiently to withstand a pressure differential of up
to about 2-4 inches of H.sub.2O thereacross.
[0077] Operation of assembly 115 will now be apparent. When
assembled, sufficient axial pressure is applied along the direction
of arrow 131, to provide an air seal end at gasket 130 and a
secondary seal at gasket 155. Debris and moisture directed into
interior 118 will generally collect in pan 150. In general,
moisture collecting along recessed surfaces 149 will be directed
downwardly toward and through aperture 151, into pan 145 of base
123, and eventually through drainage aperture 147 and outwardly
from assembly 115. It will be understood that a trough system
(analogous to that described for FIGS. 1-7) may be utilized in pan
150, if desired, to inhibit the likelihood of drainage aperture 151
becoming closed or plugged by debris.
[0078] Materials Described in Ser. No. 08/742,244
[0079] According to Ser. No. 08/742,244, while a wide variety of
materials may be utilized in the constructions, the principles
described were particularly developed for use, to advantage, with
systems constructed from certain preferred materials. In general,
the constructions were designed for utilization with sheet metal
housing systems, or stainless steel housing systems; i.e.,
arrangements wherein the housing, in particular the inlet assembly,
the can and the base, are formed from sheet metal or stainless
steel parts which are secured to one another as by welding.
Materials useful for such fabrication include 0.075-0.025
(incorrectly stated as 0.75-0.25 in the earlier disclosures) inches
thick stainless steel or sheet metal, although other thickness are
useable. Plastics can also be used.
[0080] For the arrangement of FIGS. 1-7, the preferred end cap
material described in Ser. No. 08/742,244 for forming the regions
in the end cap that need to be compressed to form a seal is a soft
polymeric material such as foamed polyurethane. Such materials
include the following polyurethane, processed to an end product
having an as molded density of 14-22 pounds per cubic foot
(lbs/ft.sup.3).
[0081] The preferred polyurethane described in Ser. No. 08/742,244
comprises a material made with I35453R resin and I3050U isocyanate.
The materials should be mixed in a mix ratio of 100 parts I35453
resin to 36.2 parts I3050U isocyanate (by weight). The specific
gravity of the resin is 1.04 (8.7 lbs/gallon) and for the
isocyanate it is 1.20 (10 lbs/gallon). The materials are typically
mixed with a high dynamic shear mixer. The component temperatures
should be 70-95.degree. F. The mold temperatures should be
115-135.degree. F.
[0082] The resin material I35453R has the following
description:
1 (a) Average molecular weight 1) Base polyether polyol =
500-15,000 2) Diols = 60-10,000 3) Triols = 500-15,000 (b) Average
functionality 1) total system = 1.5-3.2 (c) Hydroxyl number 1)
total systems = 100-300 (d) Catalysts 1) amine = Air Products
0.1-3.0 PPH 2) tin = Witco 0.01-0.5 PPH (e) Surfactants 1) total
system = 0.1-2.0 PPH (f) Water 1) total system = 0.03-3.0 PPH (g)
Pigments/dyes 1) total system = 1-5% carbon black (h) Blowing agent
1) 0.1-6.0% HFC 134A.
[0083] The I3050U isocyanate description is as follows:
[0084] (a) NCO content -22.4-23.4 wt %
[0085] (b) Viscosity, cps at 25.degree. C.=600-800
[0086] (c) Density=1.21 g/cm.sup.3 at 25.degree. C.
[0087] (d) Initial boiling pt. -190.degree. C. at 5 mm Hg
[0088] (e) Vapor pressure=0.0002 Hg at 25.degree. C.
[0089] (f) Appearance--colorless liquid
[0090] (g) Flash point (Densky-Martins closed cup)=200.degree.
C.
[0091] The materials I35453R and I3050U are available from BASF
Corporation, Wyandotte, Mich. 48192.
[0092] For the arrangement shown in FIG. 8, the filter element
includes sheet metal end caps with a fluted filter paper media
element potted therein. Conventional arrangements such as potted in
plastisol may be used.
Dimensions of a Typical Embodiment Described in Ser. No.
08/742,244
[0093] Consider an air cleaner arrangement such as depicted in FIG.
1 used on a over the highway truck (heavy duty truck). The housing
would be about 13-15 inches in diameter and about 32 inches long.
The element would be about 11-13 inches in diameter and about 23-26
inches long. The I.D. of the smallest rib on the sealing portion of
the end cap with the inlet tube (prior to compression) would be
about 6.78-7.44 inches. The I.D. of the annular surface in the
housing base whereat the radial seal with second end cap occurs
would be about 11.28-12.94 (incorrectly stated as 19.94 in Ser. No.
08/742,244) inches. The O.D. of the largest step on the second end
cap, for sealing with the base, would be about 11.4-13.06 inches.
The bead on the base for engagement with the second end cap would
be large enough to extend into the trough on the end cap about 0.35
inches. The declination angle in the second end cap from its outer
rim to the recess engaging the bead would be about 1.750. The
declination angle on the inside of the second end cap would be
about 4.degree..+-.2.degree..
Description Added to Disclosure of Ser. No. 08/742,244
[0094] It is first noted that there has been developed a preference
for application of the techniques described in Ser. No. 08/742,244
since the time of filing of that application. In particular, it is
desirable, when molding end cap 24, to provide for a media
stand-off to ensure that the media 25 is supported above a
remaining portion of a bottom surface of the mold, when the molding
occurs. The mold can be provided with a circular, raised, media
stand-off positioned in a portion of the mold underneath the media
25, during molding, to provide for this. The end cap 24 would, in
general, show an indent ring corresponding to the mold stand-off,
at a location aligned with media 25, as a result of this.
[0095] Also, hereinbelow a preferred material for use with the
embodiment of FIGS. 9-15, as the urethane material, is provided.
Such a preferred material and processes for its use, may also be
used with the embodiment of FIGS. 1-7, for both end caps.
[0096] It is also noted that the specific overall depiction of
FIGS. 9, 10, 11, 12, 13, 14 and 15 included herein, were not part
of the disclosure of Ser. No. 08/742,244. Description related to
them, has been added.
[0097] FIGS. 9-15 concern a variation in which the "closed" end cap
having the drainage aperture therein, while it comprises polymeric
material into which the ends of the inner and outer supports or
liners and media are potted, further comprises a composite of
polymeric material and a pre-formed insert. (By "pre-formed" in
this context, reference is made to the fact that the insert was
formed before a remainder of the end cap was molded.) As a result
of a preferred embodiment for achieving this, shown in FIGS. 9-15,
the inner surface of this end cap (which comprises the drainage
surface to the aperture), is physically an inner surface of the end
cap insert. This too will be understood by reference to FIGS. 9-15
and the descriptions hereinbelow.
[0098] A principal difference for the embodiment of FIGS. 9-14,
from the embodiment of FIGS. 1-7, concerns the referenced insert
and the specifically recited composite nature of the closed end cap
having the drainage aperture therein. There are, however, some
further modifications in an exterior surface of the insert. These
too will be described in connection with FIGS. 9-15.
[0099] Attention is first directed to FIG. 9. FIG. 9 is a
fragmentary cross-sectional view of an assembly according to this
alternate embodiment of the present invention. Referring to FIG. 9,
assembly 201 comprises a combination of can 204 and element 221. In
FIG. 9, reference numeral 260 generally designates an end of can
wall 261. Within end 260 is positioned a cover or base 263 of can
204. Can 204, including base 263, is configured analogously to can
4 and base 63 of FIG. 5, and thus includes, analogously: a
configuration which is preferably radially symmetric around a
central axis 233; end flange 265; center 266; sealing surface 267;
bend or corner 268; end surface 269; secondary seal bead or ridge
270; end recess 271; and, in center 266, a drainage aperture 218.
Positioned within aperture 218, is evacuation valve 219.
[0100] Still referring to FIG. 9, filter element 221 includes end
cap 224 thereon. End cap 224 comprises an appropriate material, and
is of appropriate size, so that when it is pushed into and against
base 263, an outer circumferential surface 275 of the end cap 224
engages surface 267 of base 263 in a sealing manner. That is, an
annular seal 276 is formed in region 277, circumferentially around
end cap 224. As with the embodiment of FIG. 5, this is facilitated
by preferably providing surface 267 in a cylindrical configuration
extending generally parallel to axis 233. As a result of the
circumferential seal 276, sealing against flow of air is not
required between any other portions of filter element 221 and base
263. A secondary seal 280, analogous to seal 80, FIG. 5, is
provided, however, between end cap 224 and base 263. The secondary
seal 280 inhibits movement of debris or water into region 281,
between element 221 and base 263.
[0101] It is noted that the particular configuration of outer
circumferential seal surface 275 of end cap 224, for the
arrangement shown in FIG. 9, differs from the analogous surface 67
in the embodiment of FIG. 5. A preferred configuration for surface
267 (and surface 67 if applied in the embodiment of FIG. 1) is
described hereinbelow in connection with the mold FIG. 13.
[0102] Still referring to FIG. 9, end cap 224 includes a circular
recess or trough 285 therein. Trough 285, analogously to trough 85,
FIG. 5, is sized and configured to receive and sealingly engage
bead 270. Trough 285, which, in the preferred embodiment depicted
has somewhat of an inverted "V" configuration (with a rounded apex)
when viewed in cross-section, should be sized, relative to bead
270, such that when element 221 is pressed against base 263, bead
270 is pushed into trough 285 to form a seal therewith, capable of
holding a pressure differential at least up to about 2-4 inches of
H.sub.2O.
[0103] Analogously to end cap 24 of the arrangement shown in FIG.
5, end cap 224 comprises a soft, polymeric material. However,
unlike end cap 24 shown specifically in FIG. 5, end cap 224 is a
composite. In particular, end cap 224 comprises: section 399 of
compressible, polymeric material 400; and, insert 401. Advantages
which result from the provision of the insert 401, as part of the
end cap 224, will be apparent from further descriptions
hereinbelow.
[0104] A more detailed description of the manner of construction,
to provide insert 401, is also provided hereinbelow. In general,
the insert 401 is secured to the "filter pack" which would
typically comprise media 225 (which is pleated paper in the
preferred embodiment shown), inner support 226, and outer support
227. Supports 226 and 227 could comprise, for example, conventional
perforated metal or expanded metal media liners. Inner liner 226
defines inner chamber 235 (which is cylindrical in the preferred
embodiment shown). During assembly, after the filter pack
comprising the liners 226, 227 and media 225 is prepared, insert
401 would be positioned in one end of that filter pack, closing an
end 235a of chamber 235. The assembly comprising a filter pack and
insert would then be potted within the polymeric material which is
then cured to form material 400, FIG. 9. In a typical operation,
this potting would be achieved by positioning the filter pack and
insert 401 in an appropriate mold and distributing within the mold
the uncured polymeric material, which is then cured. As a result of
the process, again described in more detail below, the insert 401
becomes permanently embedded within the material 400, to become
secured within the filter element 221 (between material 400 and
liner 226) as a part of the composite end cap 224. In the final
product, region 400 covers an underside of insert 401, except in
some instances for selected portions as described below.
[0105] Attention is now directed to FIGS. 10 and 11 in which the
details of the preferred insert 401 are depicted in detail, and
from which advantages which result from utilization of the insert
401 can be understood. Referring first to FIG. 10, which is a top
plan view of the insert 401, the insert 401 has an outer perimeter
410 (circular in the preferred embodiment shown) with depending
legs 411. The specific insert 401 depicted in FIG. 10 includes
twelve evenly radially (i.e., separated radially by 30.degree.)
spaced legs 411, each of which terminates in a foot 412. Of course,
alternate numbers and specific configurations of legs 411 and feet
412 may be used.
[0106] In general, insert 401 includes an upper surface 415, FIG.
10, and an opposite, bottom surface or lower surface 416, FIG.
11.
[0107] In general, upper surface 415 of insert 401 will, when
element 221 is assembled, generally comprise the inner surface of
composite end cap 224. Thus, surface 415 will include thereon the
inner drainage surface for directing fluid to central aperture 296
in element 224.
[0108] Referring to FIG. 11, insert 401 includes, on surface 415,
an apex or upper ridge 420. Ridge 420 is preferably a perimeter
ridge, and is circular. Preferably surface 415 includes funnel
section 421 therein, tapering downwardly from apex or ridge 420 to
central drainage aperture 422. A downward taper of 2 to 6.degree.,
typically 4.degree., will be preferred. Aperture 422 forms drainage
aperture 296, FIG. 9, in element 221. As with aperture 96, FIG. 5,
aperture 422 is substantially smaller in internal dimension, i.e.,
diameter if round, than an internal dimension (diameter) of
internal volume 235. Preferably, as with aperture 296, aperture 422
is circular, having a diameter within a range of about 0.12-1 inch,
typically about 0.47 inches, whereas an internal diameter of inner
liner 226 is typically 6-8.5 inches, typically, 6.02, 7.78, or 8.43
inches.
[0109] Referring again to FIG. 10, insert 401 includes standing
ribs or ridges 425. The ridges 425 are directed generally from
outer perimeter 410 toward aperture 422. No ridge 425, however,
extends completely to aperture 422, in the preferred embodiment
shown.
[0110] Also in the preferred embodiment shown, ridges 425 form
pairs comprising two sets of channels or troughs: troughs 428, of
which there are four depicted in the preferred embodiment; and,
troughs 429, of which there are also four in the preferred
embodiment shown. For the preferred embodiment shown, troughs 428
are identical to one another, and are separated radially by
90.degree.. Troughs 429 are also identical to one another and are
separated radially by 90.degree.. Each one of troughs 429 is evenly
spaced between two adjacent ones of troughs 428. Each of troughs
429 and 428 comprises a pair of ridges 425.
[0111] Troughs 428 differ from troughs 429 in that troughs 428 are
longer; that is, troughs 428 extend a greater percentage of the
distance toward aperture 422 from perimeter ridge 420. Troughs 429
are shorter (in elongated extension), primarily in order to leave
open spaces 431 for liquid flow on surface 415 toward aperture
422.
[0112] Between the ridges 425 defining any given trough, 428, 429,
an aperture hole through insert 401 is provided. Thus, there are
two sets of apertures: apertures 433 in troughs 428; and, apertures
434 in troughs 429. Apertures 433 and 434 are generally
oval-shaped, and act as free rise apertures to allow for free rise
of polymeric material 400 therethrough, during the molding process.
This helps secure the insert 401 as part of the composite end cap
224. It also facilitates a controlled molding process, as described
below. The ridges 425 help contain the rising polymeric material
400, during the molding process, in part to maintain substantial
portions of surface 415 open, for free fluid flow thereacross.
[0113] Note that as a result of the ridges 425 being raised above
surface 415, improvement in liquid flow across surface 415 is
provided. This is in part because leaf material, paper material,
etc., which settles into element 221 may, at least in some
instances, be supported above surface 415 by the ridges 425.
[0114] Attention is now directed to FIG. 11. From FIG. 11, it can
be understood that depending legs 411 generally bow outwardly from
ridge 420, depending from surface 416. Preferably, each leg 411 is
about 0.625 inches long in extension between ridge 420 to the
bottom tip of beads 440, FIG. 11.
[0115] Preferably an outer radius defined by the perimeter of the
legs at regions 430, is slightly larger than the inner dimension
(diameter) of liner 235; and, legs 411 are sufficiently thin to
flex inwardly somewhat, when pressed into an end of inner liner
235, during assembly. This "spring" effect can be used to
temporarily secure insert 401 to liner 235 in the filter pack,
during the molding operation, as described below. Preferably, the
outer radius of the legs at regions 430 is about 0.25 inches.
[0116] Each leg 411 extends slightly outwardly from the vertical.
This is to help facilitate manufacturing of the insert 401, so that
it may be more easily pulled from its mold. Preferably, each leg
411 extends at an angle of about 5.degree. from vertical.
[0117] Each leg 411 includes a tapered rib 413 extending therefrom.
Each rib 413 extends from just above an upper surface 441 of each
foot 412 to just below the radiussed surface 430. Ribs 413 help to
temporarily secure insert 401 to liner 235 in the filter pack,
during the molding operation, as described below. Preferably, each
rib 413 is about 60 thousandths of inch thick, and extends a length
of about 0.3 inches. Each rib 413 extends about 1.degree. from
vertical.
[0118] Still referring to FIG. 11, each foot 412 includes a bottom
bead 440 thereon. The bottom bead 440 operates as a mold stand-off,
during molding. In particular, bottom beads 440 will support a
reminder of insert 401 above a lower surface of a mold, during a
molding operation, to help ensure that a remainder of insert 401
will be embedded within the resin, during the molding operation.
After molding, beads 440 will either be slightly exposed in the
molded end cap, or they will be covered by a thin layer of molded
material, depending upon the molding operation. Either condition is
acceptable. Preferably, each bead 440 extends at a radius of about
0.06 inches.
[0119] Each foot also includes an upper surface 441. The upper
surface is preferably at least 0.375 inches long, and, during
assembly, will extend beyond the filter pack inner liner 235 to
positions underneath the filter media 225. As a result of being
positioned underneath the filter media 225 during assembly with a
filter pack, upper surfaces 441 of the feet 412 will operate as
media stand-offs, during molding. This will prevent the media 225
from dropping all the way to the bottom of the mold cavity.
[0120] Still referring to FIG. 11, attention is directed to a
portion of surface 416 which circumscribes aperture 422. That
portion or region is indicated generally at reference numeral 450.
Within this region is located a circular trench 451. (Circular when
viewed in bottom plan view.) The circular trench 451 preferably has
a semi-circular cross-section as shown in FIG. 11, although
alternative configurations can be used. During the molding
operation, trench 451 will be aligned with, and receive, a bead in
the mold. This will inhibit, during molding, flow of resin along
the direction indicated generally by arrows 452, past surface 450
and into aperture 422. The result will be an inhibition of
polymeric flash at, or in, aperture 422.
[0121] As a result, it is anticipated that after a molding
operation, certain portions of surface 450, indicated generally at
455 between trough 451 and aperture 422, will generally be exposed,
except perhaps for some small amount of flash from the molding
operation. The exposed surface 455 is viewable in FIG. 14, a bottom
plan view of element 221.
[0122] Advantages to a composite end cap 224 including an insert
such as that shown in FIGS. 10 and 11, result from at least two
related concerns. First, it is anticipated that insert 401 will
typically be manufactured from a material that can be molded, for
example a molded, rigid, polystyrene or similar material. As a
result of such a molding, specific configurations can be readily
provided to surface 415 to achieve advantageous fluid flow effects
and similar effects without relying upon control of conditions used
to mold material 399, 400. Thus, the surface features of surface
415 are not achieved during the same operation in which the soft,
polymeric material for the remainder of end cap 224, i.e., material
400, is formed.
[0123] In addition, the molding process to provide for polymeric
material 400 is facilitated. This is because a "closed mold"
process is not required. Rather, free rise of the polymeric
material 399 is accommodated because insert 401, including
apertures 433 and ridges 425, will control and direct rise. The
free rise will not effect the downward slant in regions 421, to
achieve a desirable drainage effect in insert 401, since the inner
surface 415 of the end cap 224 is pre-formed.
[0124] In general, when the end cap 424 comprises a composite of an
insert 401 and polymeric material 400 as described herein, the
polymeric material may comprise the preferred polyurethane
described in application Ser. No. 08/742,244, and previously
herein, molded end or similar conditions.
[0125] However, preferably the urethane comprises a material made
with Elastofoam I36070R resin and Elastofoam I3050U isocyanate as
described below. The material should be mixed as described above,
except with I36070R, replacing the I35453R resin. For this
material, the mold temperature should preferably be about
105.degree.-150.degree. F.
[0126] The resin material I36070R has the following:
2 (a) Average molecular weight 1) Base polyether polyol =
500-15,000 2) Diols = 60-10,000 3) Triols = 500-15,000 (b) Average
functionality 1) total system = 1.5-3.2 (c) Hydroxyl number 1)
total systems = 100-300 (d) Catalysts 1) amine = Air Products
0.1-3.0 PPH (e) Surfactants 1) total system = 0.1-2.0 PPH (f) Water
1) total system = 0.03-3.0 PPH (g) Pigments/dyes 1) total system =
1-5% carbon black
[0127] The Elastofoam I3050U isocyanate description is as
follows:
[0128] (a) NCO content--22.4-23.4 wt. %
[0129] (b) Viscosity, cps at 25.degree. C.=600-800
[0130] (c) Density=1.21 g/cm.sup.3 at 25.degree. C.
[0131] (d) Initial boiling pt.--190.degree. C. at 5 mm Hg
[0132] (e) Vapor pressure=0.0002 Hg at 25.degree. C.
[0133] (f) Appearance--colorless liquid
[0134] (g) Flash point (Densky-Martins closed cup)=200.degree.
C.
[0135] The materials Elastofoam I36070R and Elastofoam I3050U are
available from BASF Corporation, Wyandotte, Mich. 48192.
[0136] Preferably the insert comprises a rigid material, such as
molded polystyrene. Of course, a variety of specific configurations
and alternatives to the arrangement shown in FIGS. 10 and 11 can be
used. However, preferred configurations and dimensions are provided
herein.
[0137] With respect to the liner material, no particular preference
is made. In general, it is foreseen that the liner will comprise
either perforated metal or expanded metal, for example G60
galvanized steel, having a thickness of about 0.03 inches. Such
liners are commonly used in other types of large filter elements
for trucks, for example.
[0138] As to the filter material, with respect to the principles of
the present invention, no particular preference exists. The
principles of the present invention can be applied with any of a
wide variety of materials. For example, pleated paper or cellulose
materials, such as conventionally used in truck filters, may be
used. Synthetic materials, or cellulose materials, having synthetic
(polymeric or glass) fibers applied thereto, may also be used.
Expanded polytetrafluoroethylene layers, applied on a surface, or
in composites, may be used. In addition, nonwoven fibrous
constructions, or composites of nonwoven fibrous media and pleated
media, may also be used. Indeed, arrangements not existing and yet
to be developed can be accommodated, by composite end caps made
according to the processes described herein. This will be apparent,
from a more detailed description of the method of assembly.
[0139] In FIG. 12, a schematic representation of a preferred
process for manufacturing a filter element according to the
composite of FIGS. 9, 10 and 11 is provided.
[0140] Referring to FIG. 12, a filter pack is indicated generally
at 500. The filter pack comprises outer liner 227, media 225, and
inner liner 226. The filter pack 500 is shown aligned to receive
insert 401 therein, with feet 411 positioned under media 225, and
with a remainder of insert 401 positioned within inner chamber 235.
The combination of filter pack 500 and insert 401 would then be
positioned within mold 501. The appropriate resin mix would be
positioned in the mold as well, and cured. Again, free rise
conditions for curing are allowable, due in part to the design of
insert 401.
[0141] Attention is directed to FIG. 13, which indicates a
schematic cross-section of a usable mold 501. Note the mold
includes bead 502 for engagement with trough 451 in insert 401,
FIG. 11, discussed above. Center post 503 fits through aperture 422
in insert 401, and ensures a proper positioning as well as
inhibition of flash within the aperture 422. Note the positioning
of bead 504, which will generate trough 285, FIG. 9. Also note the
positioning of stand-off 505, which is formed as a ring in mold
501. Stand-off 505 will receive beads 440 positioned thereon,
during molding. This is illustrated in FIG. 15, schematically, in
which insert 401 is shown positioned within mold 501.
[0142] Some Preferred Dimensions for Arrangements According to
FIGS. 9-15
[0143] Consider an air cleaner arrangement such as depicted in FIG.
1 used on a over the highway truck (heavy duty truck). The housing
would be about 11-15 inches in diameter and about 32 inches long.
The element would be about 9-13 inches in diameter and about 22-26
inches long. The I.D. of the smallest rib on the sealing portion of
the end cap with the inlet tube (prior to compression) would be
about 5.15 inches. The I.D. of the annular surface in the housing
base whereat the radial seal with second end cap occurs would be
about 9.52 inches. The O.D. of the largest step on the second end
cap, for sealing with the base, would be about 9.64 inches. The
bead on the base for engagement with the second end cap would be
large enough to extend into the trough on the end cap about 0.35
inches. The declination angle in the second end cap from its outer
rim to the recess engaging the bead would be about 1.75.degree..
The declination angle on the inside of the second end cap would be
about 4.degree..+-.2.degree..
[0144] The standing ribs or ridges 425 on the insert would have a
height of about 0.077 inches, and a thickness at a distal end (free
end) of about 0.042 inches. Each of the ridges 425 between the base
proximate to the regions 421 and the free end would be curved on a
radius of about 0.062 inches. The distance between a pair of free
ends of two of the ridges would be about 0.4 inches. Apertures 433
and 434 would have radii at each respective end of about 0.125
inches.
[0145] Circular trench 451 would have a semi-circular
cross-section. The radius of the cross-section would be about 0.031
inches. The diameter of circular trench 451 would be about 0.736
inches.
[0146] The diameter for the insert extending from the outermost end
tip of one of the feet to the outermost end tip of a diametrically
opposite foot would be about 9.265 inches. The diameter of the
insert extending from the outermost part of one of the legs (not
including the foot) to the outermost part of a diametrically
opposite leg (not including the foot) would be about 8.515 inches.
The inner radius of each leg 411 as it bends from a top surface of
the insert down toward its foot would be about 0.187 inches. The
outer radius of each leg 411 as it bends from a top surface of the
insert down toward its foot would be about 0.25 inches. The radius
of each leg 411 as it bends from its substantially vertically
extension to its foot would be about 0.03 inches. The radius of
each bead 440 would be about 0.06 inches. The angle of declination
at ramp section 453 would be about 30.degree. from horizontal, and
on a radius of about 0.125 inches.
[0147] Each rib 413 on legs 411 would be about 60 thousandths of
inch thick, and extend a length of about 0.3 inches. Each rib 413
would extend about 10 from vertical. Each leg 411 would extend at
an angle of about 5.degree. from vertical, and be about 0.625
inches long in extension between ridge 420 to the bottom tip of
beads 440. The upper surface of each foot would be about 0.375
inches long.
* * * * *