U.S. patent application number 14/178353 was filed with the patent office on 2014-08-14 for filter body.
This patent application is currently assigned to MANN+HUMMEL GMBH. The applicant listed for this patent is MANN+HUMMEL GMBH. Invention is credited to Michael Kaufmann, Joachim-Paul Krieger, Friedrich Kupfer, Klaus-Dieter Ruhland, Thomas Vilsmaier.
Application Number | 20140223869 14/178353 |
Document ID | / |
Family ID | 51226346 |
Filed Date | 2014-08-14 |
United States Patent
Application |
20140223869 |
Kind Code |
A1 |
Kaufmann; Michael ; et
al. |
August 14, 2014 |
Filter Body
Abstract
A filter body has a longitudinal axis and a first end face and a
second end face opposite the first end face in a direction of the
longitudinal axis. The filter body has a zigzag-folded filter
medium arranged about the longitudinal axis, wherein the filter
body has an inner circumference and an outer circumference and fold
edges of the filter medium are positioned on the inner
circumference and/or the outer circumference. The filter body
further has a securing coil of at least one circumferentially
extending thread applied onto the outer circumference. The fold
edges have, at least over sections thereof, several embossments
arranged such that the fold edges that are next to each other are
secured relative to each other by the embossments.
Inventors: |
Kaufmann; Michael;
(Meckenheim, DE) ; Ruhland; Klaus-Dieter;
(Meckenheim, DE) ; Kupfer; Friedrich; (Poxau,
DE) ; Vilsmaier; Thomas; (Marklkofen, DE) ;
Krieger; Joachim-Paul; (Reisbach, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MANN+HUMMEL GMBH |
LUDWIGSBURG |
|
DE |
|
|
Assignee: |
MANN+HUMMEL GMBH
LUDWIGSBURG
DE
|
Family ID: |
51226346 |
Appl. No.: |
14/178353 |
Filed: |
February 12, 2014 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
61815214 |
Apr 23, 2013 |
|
|
|
Current U.S.
Class: |
55/332 ; 55/486;
55/498 |
Current CPC
Class: |
F02M 35/0216 20130101;
F02M 35/02483 20130101; F02M 35/02416 20130101; B01D 46/0004
20130101; F02M 35/0245 20130101; F02M 35/08 20130101; B01D 2265/06
20130101; B01D 2265/021 20130101; F02M 35/02425 20130101; F02M
35/084 20130101; B01D 45/16 20130101; B01D 50/002 20130101; B01D
46/0041 20130101; B01D 46/008 20130101; F02M 35/0223 20130101; B01D
46/2411 20130101; F02M 35/0214 20130101; B01D 46/523 20130101; F02M
35/0205 20130101; B01D 46/0005 20130101; B01D 46/2414 20130101;
B01D 46/4227 20130101 |
Class at
Publication: |
55/332 ; 55/498;
55/486 |
International
Class: |
F02M 35/024 20060101
F02M035/024; F02M 35/02 20060101 F02M035/02; F02M 35/022 20060101
F02M035/022 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 12, 2013 |
DE |
10 2013 002 274.6 |
Feb 12, 2013 |
DE |
10 2013 002 275.4 |
Feb 12, 2013 |
DE |
10 2013 002 276.2 |
Feb 12, 2013 |
DE |
10 2013 002 277.0 |
Feb 12, 2013 |
DE |
10 2013 002 278.9 |
Claims
1. A filter body having a longitudinal axis and a first end face
and a second end face opposite the first end face in a direction of
the longitudinal axis, wherein the filter body is comprised of a
zigzag-folded filter medium arranged about the longitudinal axis,
wherein the filter body has an inner circumference and an outer
circumference and fold edges of the filter medium are positioned on
the inner circumference and/or the outer circumference, and is
further comprised of a securing coil of at least one
circumferentially extending thread applied onto the outer
circumference, wherein the fold edges have, at least over sections
thereof, several embossments arranged such that the fold edges that
are next to each other are secured relative to each other by the
embossments.
2. The filter body according to claim 1, wherein the filter medium
is paper, paper reinforced with plastic fibers, and/or
plastic-coated paper.
3. The filter body according to claim 1, wherein the securing coil
comprises at least one thread extending in the direction of the
longitudinal axis on the outer circumference.
4. The filter body according to claim 1, wherein the securing coil
is comprised of a plastic-impregnated thread.
5. The filter body according to claim 1, wherein the securing coil
is glued onto the filter medium.
6. The filter body according to claim 1, further comprising a
reinforcement ring disposed on at least one of the first and second
end faces.
7. A filter element comprising: a filter body according to claim 1;
a first end disk arranged at the first end face of the filter body
and a second end disk arranged at the second end face of the filter
body; a support tube that is concentrically arranged relative to
the longitudinal axis of the filter body and extends between the
first and the second end disks.
8. The filter element according to claim 7, wherein the second end
disk is comprised of a polyurethane foam or an elastomer.
9. The filter element according to claim 7, wherein the first end
disk has a radial seal for sealing relative to a housing.
10. The filter element according to claim 7 as an air filter.
11. The filter element according to claim 7 as a filter element of
an internal combustion engine.
12. The filter element according to claim 7 as a particulate
filter.
13. The filter element according to claim 7 as a diesel particulate
filter of an internal combustion engine.
14. A filter system comprising; a housing that is configured
substantially concentrically about a longitudinal axis; a cover
closing off the housing and concentrically configured relative the
longitudinal axis; a filter element according to claim 7 disposed
exchangeably in the housing; an inlet arranged at the housing
and/or the cover wherein a medium to be filtered is supplied via
the inlet; an outlet arranged concentrically on the housing
relative to the longitudinal axis, wherein filtered medium is
discharged via the outlet; wherein a sealing contour is provided on
the housing in the area of the outlet, wherein the sealing contour
corresponds with a radial seal of the first end disk of the filter
element.
15. The filter system according to claim 14, further comprising a
cyclone separator disposed in the area of the inlet and further
comprising a dirt outlet disposed at the housing or at the
cover.
16. The filter system according to claim 14, further comprising a
secondary element arranged in an interior of the filter
element.
17. The filter system according to claim 16, wherein the secondary
element is connected to the housing and remains within the housing
when the filter element is exchanged.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 61/815,214 filed: Apr. 23, 2013. This application
claims foreign priority under 35 USC 119(b) to prior filed German
patent applications 10 2013 002 274.6 filed Feb. 12, 2013; 10 2013
002 275.4 filed Feb. 12, 2013; 10 2013 002 277.0 filed Feb. 12,
2013; 10 2013 002 278.9 filed Feb. 12, 2013; and 10 2013 002 276.2
filed Feb. 12, 2013, the entire contents of the aforesaid U.S.
Provisional Application and the aforesaid German patent
applications being incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The invention concerns a filter body, in particular for use
as an air filter of an internal combustion engine, as well as a
filter element with a filter body and a filter system for
installation of such a filter element.
[0003] WO 2009/047196 A1 discloses a filter element for internal
combustion engines that is comprised of a zigzag-folded filter
medium in a concentric shape, a first open or closed end disk
arranged on an end face and a second end disk arranged on the
oppositely positioned end face wherein the end disk has a
concentric opening and extends substantially as a circular ring
across the folds of the filter medium. The filter element has
annular beads and sealing grooves for sealing the filter element in
a housing.
[0004] Moreover, WO 2009/047196 A1 discloses a filter system with a
filter element. This filter system serves in particular for
filtration of the intake air of an internal combustion engine and
is comprised of a housing and a removable cover for receiving the
filter element. The filter system has two annular grooves that
communicate with the sealing contours of the filter element in the
area of the sealing action.
[0005] In principle, the reliable sealing action of a filter
element in a housing is important for reliable operation. The
sealing action should be temperature-resistant and
vibration-resistant. The sealing action of the filter element must
be ensured also in connection with devices or facilities that are
exposed to strong vibrations or impacts. At the same time, the
filter element should, if possible, contain no metallic parts so
that it can be thermally disposed of without problems. In order to
ensure these properties, a high mechanical stability of the filter
element, whose filter medium usually consists of paper or nonwoven,
is required for the duration of the entire service life.
[0006] It is therefore an object of the invention to design a
filter body for a filter element such that a high mechanical
stability of the filter element for the duration of its service
life is ensured, even under unfavorable environmental conditions
such as moisture and/or great temperature fluctuations.
[0007] A further object of the invention is to provide a filter
system with such an exchangeable filter element that exhibits a
high mechanical stability for the duration of its service life,
even under unfavorable environmental conditions such as moisture
and/or great temperature fluctuations.
SUMMARY OF THE INVENTION
[0008] In accordance with the present invention, this is achieved
according to one aspect of the invention with a filter body that
has fold edges arranged on the inner and/or outer circumference of
the filter body, wherein the fold edges, at least over sections
thereof, have several embossments that secure neighboring fold
edges relative to each other and wherein a securing coil of at
least one circumferentially extending strip or thread is provided
on the outer circumference of the filter body.
[0009] According to another aspect of the invention, a filter
system with such a filter body is provided.
[0010] Accordingly, a filter body having a longitudinal axis and
two end faces is proposed that comprises a filter medium that is
arranged about a longitudinal axis a zigzag-folded shape and has an
inner circumference and an outer circumference. The fold edges of
the zigzag shape are arranged on the inner and/or outer
circumference of the filter body and the fold edges, at least over
sections thereof, have several embossments which secure neighboring
fold edges relative to each other and wherein a securing coil of at
least one circumferentially extending strip or thread is applied to
the outer circumference of the filter body
[0011] The embossments can be applied, for example, by rolling of
the folded filter medium wherein the fold edges of the folded
filter medium are depressed at sequentially arranged fold edges in
a defined way. The fold edge widens at the rolled location and can
thus be supported on the embossment of the neighboring fold edge.
In this way, the filter body can be advantageously stabilized
relative to deformation. The embossments can be arranged as a
circumferential structure on the circumferential surface of the
filter medium at the same axial height. Conceivable is also to
design the embossments so as to alternate on the circumferential
surface with areas that are not embossed, instead of providing
circumferentially arranged embossments. In this case, it is
advantageous when embossed and non-embossed areas at the
circumference are staggered relative to each other for axially
neighboring embossments.
[0012] By supporting the fold edges by means of a combination of
embossments on the outer circumference and/or on the inner
circumference of the filter body, i.e., at the incoming flow side
and/or at the outgoing flow side of the filter body, and of
securing coils, the folds are uniformly distributed in the
circumferential direction. By combination of the embossments at the
incoming flow area and/or outgoing flow area of the filter body and
the fixation by the securing coil, an advantageously arranged fold
position and fold distribution results. This combination of
measures provides straightness of the folds in their length-wise
extension in the direction of the longitudinal axis of the filter
body which is very beneficial relative to variants employing a
support action solely by embossments or solely by spiral securing
coils. Effects like compaction, slanted or tilted positioning, or
wave formation of the folds of the filter medium by environmental
influences, such as water, moisture in the air, temperature and the
like are significantly reduced with this arrangement. The
embossments ensure a uniform spacing of the folds and thus provide
an optimal passage for the incoming medium. Moreover, a defined
dust pocket remains that counteracts compaction of the folds. The
securing coil secures the fold spacing that is adjusted by the
embossments and ties the filter medium to a compact filter body.
The stiffness of the filter body remains intact in this way. In
addition, the filter body absorbs, without fold deformation, the
axial clamping forces occurring upon installation of a filter
element constructed from the filter body in a housing.
[0013] In a beneficial embodiment, the filter medium can be made of
paper, paper reinforced with plastic fibers, and/or plastic-coated
paper. The use of these materials as a filter medium represents a
very economic possibility for realizing such a filter element. At
the same time, the described shaping provides a stable arrangement
so that a self-supporting configuration of the filter body and thus
beneficial mounting properties are provided.
[0014] Advantageously, the securing coil may comprise at least one
strip or thread extending in the direction of the longitudinal axis
on the outer circumference of the filter body. With additional
strips or threads perpendicular to the circumferentially extending
threads or strips on the outer circumference of the filter body,
the securing coil can be additionally reinforced and is thus
suitable for very rough environments. Also, very large and heavy
filter bodies, for example, for use in construction machines or
agricultural machinery can be additionally stabilized in this
way.
[0015] In one embodiment, one or several strips or threads are
wound in a coil shape about the outer circumference to form the
securing coil. In this connection, it can be advantageous to
provide areas with different pitch. For example, in the area
adjacent to the closed end disk, the thread can be wound with
reduced pitch so that the threads or strips are closer to each
other, for example, spaced by less than 2 cm (0.8 inches),
preferably approximately 1 cm (0.4 inches). In this way, in this
area a grip or handling-resistant zone can be provided in which the
filter medium is reinforced for absorbing the manually applied
operating forces when exchanging the filter element.
[0016] Expediently, the securing coil can be comprised of
plastic-impregnated thread or strip. Such threads or strips have
the advantage that they are moisture-resistant, have an excellent
long term behavior, and also exhibit additional strength so that
the filter body as a whole is more stable.
[0017] In an advantageous embodiment, the securing coil can be
glued onto the filter medium. The strip or thread of the securing
coil can be wound from a bath of hot-melt adhesive onto the filter
body. When the filter body with securing coil is subsequently
subjected to a heat treatment, the hot-melt adhesive can fuse with
the filter medium and cure and, in this way, imparts to the
securing coil and the filter body a significant strength.
Alternatively, other curing methods, depending on the employed
glue, can be used. For example, curing methods employing UV light
can be used also.
[0018] Advantageously, the filter body can have at least at one end
face a reinforcement ring. In this way, the filter body is provided
with a further stabilizing element that, together with the
combination of embossments and securing coil, serves for improved
absorption of the axial clamping forces upon installing a filter
element made therefrom in a housing.
[0019] The invention concerns according to a further aspect a
filter element that comprises a filter body, a first open or closed
end disk that is arranged at an end face and a second end disk that
is arranged at the second oppositely positioned end face as well as
a support tube concentrically arranged relative to the longitudinal
axis and extending between the first and second end disks. Such a
filter element is ready to be mounted and can be used in a filter
system, for example, of an internal combustion engine. In this
context, the two end disks and the support tube serve for mounting
and sealing in the housing of the filter system.
[0020] Advantageously, the second end disk, like the first end
disk, can be comprised of polyurethane foam or an elastomer. Of
course, there is also the possibility to produce the end disk from
several plastic components in order to ensure an optimal
deformability across a wide temperature range, which may be
encountered when using the filter element in practice. Accordingly,
thermoplastic synthetic materials are not excluded. Both end disks
can be fused (welded) or glued to the filter body in order to
provide a stable connection.
[0021] Expediently, the first end disk can have a radial seal
relative to the housing. This has the advantage that in addition to
an excellent sealing action and thus a safe filtering action, due
to the radial seal a radial guiding of the filter element in the
housing can be effected and, in this way, a very stable securing
action of the filter element in the housing is provided.
[0022] Expediently, the filter element can be used as an air
filter, in particular as an air filter of an internal combustion
engine. The safe operation of internal combustion engines is based
also on a safe and favorable filtering of the intake air for
combustion. The disclosed filter element provides an economic
possibility for this purpose.
[0023] Advantageous is also the use of the filter element as a
particulate filter, in particular as a diesel particulate filter of
an internal combustion engine. Here also safe mounting and economic
exchangeability of the described filter element are of decisive
importance.
[0024] The invention concerns, according to a further aspect, a
filter system with a filter element, comprising a housing which is
substantially concentrically configured about a longitudinal axis;
a cover that closes off the housing and that is also concentrically
designed relative to longitudinal axis; an inlet arranged on the
housing and/or the cover for supply of the medium to be filtered,
in particular air; wherein on the housing, concentric to the
longitudinal axis, an outlet for discharging the filtered medium is
provided; wherein on the housing in the area of the outlet a
sealing contour is provided which corresponds with the radial seal
of the first end disk of the filter element; wherein the filter
element is exchangeably arranged in the housing of the filter
system. The important advantage of such a filter system resides in
the very safe and stable installation of the filter element as well
as in the economic exchangeability or replacement of the filter
element in a service situation. Especially for a short service
life, as in use in the field of agricultural or construction
machinery, the fast exchangeability is of great importance.
[0025] Advantageously, in the area of the inlet of the filter
system, a cyclone separator can be provided and a dirt outlet can
be provided on the housing or on the cover. This cyclone separator
is comprised of a guiding geometry that causes the medium to be
filtered to rotate. Due to this rotation, the dirt is concentrated
in the area of the housing wall and is discharged at a suitable
location by means of the dirt outlet. By preseparation of most of
the dirt from the air to be filtered, the service life of the
actual filter element can be decisively prolonged.
[0026] According to a further embodiment of the invention, a
secondary element can be arranged in the interior of the filter
element. The secondary element that may be comprised of a support
structure that is covered with a permeable filter medium, for
example, a nonwoven, has the task of keeping closed the outlet of
the filter system during exchange of the filter element so that no
dirt can penetrate into this area while the filter element is
cleaned or replaced. The secondary element in a preferred
embodiment is connected by a screw connection with the housing and
is provided with a seal relative to the housing.
BRIEF DESCRIPTION OF THE DRAWING
[0027] Further advantages result from the following description. In
the drawing, exemplary embodiments of the invention are illustrated
without being limiting. The drawings, the description, and the
claims contain several features in combination. A person of skill
in the art will consider the features expediently also individually
and will combine them to other meaningful combinations.
[0028] FIG. 1 shows in a perspective view a filter system according
to an embodiment of the invention with tangential inlet, central
outlet, and dirt outlet at the bottom side.
[0029] FIG. 2 shows in a perspective view a filter system according
to an embodiment of the invention with radial inlet and central
outlet.
[0030] FIG. 3 is a longitudinal section of the filter system
according to an embodiment of the invention with tangential inlet,
central outlet, and dirt outlet at the bottom side.
[0031] FIG. 4 is a schematic illustration of a filter body
according to the prior art with embossments on the inner and outer
circumference of the filter body.
[0032] FIG. 5 is a schematic illustration of a filter body
according to an embodiment of the invention with embossments on the
inner and outer circumference of the filter body as well as a
securing coil on the outer circumference.
[0033] FIG. 6 is a schematic illustration of a filter body
according to a further embodiment of the invention with embossments
on the inner and outer circumference of the filter body, a securing
coil on the outer circumference, and a reinforcement ring at an end
face.
[0034] FIG. 7 is a filter element made of a filter body according
to FIG. 5
[0035] FIG. 8 is a longitudinal section of the filter element
according to FIG. 7.
[0036] FIG. 9 is an enlarged view of a part of the longitudinal
section through the filter element according to FIG. 7.
[0037] In the Figures, same components or components acting in the
same way are identified with the same reference characters. The
Figures show only exemplary embodiments and are not to be
understood as limiting.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0038] FIG. 1 shows in a perspective view a filter system 100
according to an embodiment of the invention with tangential inlet
102, central outlet 104 at an end face of the housing, and a dirt
outlet 106 at the bottom side. Illustrated is a round filter
configuration that is comprised of a housing 108 that is closed off
by a cover 110, for example, by a screw connection or bayonet
coupling connection. When used as an air filter system, dust-laden
air flows into the inlet 102 that is arranged tangential to the air
filter element arranged in the interior of the housing so that the
air in the interior of the housing 108 is caused to rotate by an
incoming flow protector at the filter element. Filter element and
incoming flow protector are not illustrated in the drawing. Due to
the cyclone effect caused by the rotational movement of the air,
centrifugal forces are acting on the dust particles contained in
the incoming air so that the dust particles are partially separated
at the housing wall and can be discharged by means of dirt outlet
106 from the filter system 100. In this way, the filter element is
loaded less and the service life of the filter element is
increased. The purified air can be discharged via the central
outlet 104 from the housing 108.
[0039] FIG. 2 shows a perspective view of a filter system 100
according to an embodiment with inlet 102 at the cover and central
outlet 104. Illustrated is also a round filter configuration
comprised of a housing 108 that is closed off by a cover 110. The
inlet through which the dust-laden air can enter the housing is in
this case arranged centrally above the filter element installed in
the interior. The outlet 104 through which the purified air can
flow out is centrally arranged, as also shown in FIG. 1.
[0040] Such filter systems as illustrated in FIGS. 1 and 2 are
usually employed in construction machinery and agricultural
machinery. They are characterized by great robustness and have a
short service life due to their high dust load. A filter system 100
with loaded filter element must be able to tolerate a weight
increase of 10 kg or more.
[0041] In FIG. 3 a longitudinal section of the filter system 100
according to an embodiment of the invention with tangential inlet
102, central outlet 104, and dirt outlet 106 at the bottom side is
illustrated. The housing 108 of the filter system 100 is closed off
by a cover 110. The filter element 10 that is comprised of a
support tube 14 concentrically arranged about longitudinal axis L
and the filter body 12 is provided at two opposite end faces 15, 17
with first and second end discs 16, 18 that are, for example, made
of castable polyurethane, in particular polyurethane foam, or an
elastomer. The second end disk 18 and the support tube 14 of the
filter element 10 may be configured together as a monolithic
component. The filter body 12 can be folded, for example, in a
zigzag shape, can be of an annularly closed configuration, and can
be comprised of paper, paper reinforced with plastic fibers, and/or
of plastic-coated paper.
[0042] The second end disk 18 whose stability is increased by a
reinforcement plate 30 has support knobs 20 which, upon
installation into the housing 108 provided for receiving the filter
element, are supported axially as well as radially on the housing
108 by contacting an inner cover contour 114 of the cover 110. On
the oppositely positioned end face 15 of the filter element 10, a
radial seal 26 is provided on the first end face 16 whose stability
is increased by the reinforcement ring 31. With the radial seal 26,
the filter element 10 is radially supported via sealing contour 116
on the housing 108 and seals the unfiltered air chamber relative to
the filtered air chamber. The filter element 10 is thus axially as
well as twice radially clamped relative to the housing 108.
[0043] Dust-laden air can be flowing in through the inlet 102 in
the direction of arrow 40; the inlet 102 is in this case
illustrated as a tangential inlet and enables, due to the
rotational movement of the air which is effected by the cyclone
separator 36, a cyclone operation. Dust particles, partially
pre-separated by the rotational movement, can deposit on the inner
housing wall and by means of the dirt outlet 106, in case of
installation of the filter housing 108 in horizontal position, can
be discharged in downward direction by the force of gravity from
the filter system 100. In operation, the air flows, after partial
separation of the dust particles, through the filter body 12 in the
direction of arrows 42, 44 into the interior 50 of the filter
element. Dust particles are retained within the filter medium,
beginning at a certain size of the particles that depends on the
filter medium. Depending on the dust load, the filter element 10
must be exchanged after a certain operating time.
[0044] Via the outlet 104, the filtered air flows in the direction
of arrow 46 out of the system. In the interior 50 of the filter
element 10, i.e., in the clean air area, a secondary element 28 is
provided that is substantially comprised of a support structure
with a filter medium that has a relatively high permeability, for
example, a nonwoven, and upon exchange of the filter element 10
remains in the housing 108 for protecting the downstream air
guiding passage, for example, of an internal combustion engine,
against penetration of dust particles and other objects. The
secondary element 28 is fixedly screwed on by a screw-on part 32
onto the outlet-side component of the housing 108 and is sealed by
a radial seal.
[0045] FIG. 4 shows a purely schematic illustration of a filter
body 12 with end faces 52, 54 according to the prior art with
embossments 64 on the inner and outer circumference 58, 60 of the
filter body 12. The filter body 1, illustrated purely schematically
in the shape of a hollow cylinder of the filter medium 56 without
providing details of the zigzag-folded filter medium, has
embossments 64 which are arranged in an annular shape on the inner
as well as outer circumference 58, 60 of the filter body 12. In
principle, these embossments 64 in the filter medium 56 can be
produced prior to producing the filter body 12 in the semi-finished
product, i.e., in the folded paper. Conceivable is however also an
embossment process by means of suitable embossment stamps after the
filter body 12 has been converted into its final shape.
[0046] In a concrete embodiment, the filter body 12, with its
longitudinal axis L and two end faces 52, 54, comprises a filter
medium 56 that is arranged about longitudinal axis L and is folded
in a zigzag shape and provided with an inner circumference and an
outer circumference 58, 60. Fold edges 62 are positioned on the
inner and/or outer circumference 58, 60 of the filter body 12 and
the fold edges 62 at least partially have several embossments 64
which secured neighboring fold edges 62 relative to each other.
[0047] It is beneficial when the filter medium 56 is made of paper,
paper reinforced with plastic fibers, and/or plastic-coated
paper.
[0048] FIG. 5 shows also in a purely schematic illustration a
filter body 12 with the end faces 52, 54 according to an embodiment
of the invention with embossments 64 on the inner and outer
circumference 58, 60 of the filter body 12 as well as a securing
coil 66 on the outer circumference 60. In addition to the annular
embossments 64, annular threads of a securing coil 66 are provided.
The securing coil is provided on the outer circumference 60 of the
filter body 12 for reinforcement of the entire composite. The inner
circumference 58 of the filter body 12 is simply embossed with
embossments 64.
[0049] In the concrete embodiment of the invention, the filter body
12 is provided in addition to the embossments 64 with a securing
coil 66 of at least one circumferentially extending thread or strip
68 on the outer circumference 60 of the filter body 12. Further,
the securing coil 66 can have at least one thread 68 perpendicular
to the circumferentially extending threads in the direction of the
longitudinal axis L on the outer circumference 60 of the filter
body 12 in order to thereby additionally stiffen or reinforce the
filter body 12. The securing coil 66 can be expediently comprised
of a plastic-impregnated thread or strip in order to protect the
thread/strip from the effects of moisture. The securing coil 66 can
moreover be secured on the filter medium 56 by a hot-melt adhesive
connection after application on the outer circumference 60 of the
filter body 12.
[0050] In FIG. 6, a filter body 12 according to a further
embodiment of the invention is illustrated purely schematically.
The filter body 12 is provided with embossments 64 on the inner and
outer circumference 58, 60 of the filter body 12, a securing coil
66 on the outer circumference 60, as well as a reinforcement ring
70 on an end face 54. In one area of the filter body 12, an
improper handling protector 72 (protector to prevent damage by
improper handling) in the form of, for example, a film is
illustrated by means of which the filter body 12 as a finished
filter element can be installed in and removed from a housing by
hand.
[0051] FIG. 7 shows a filter element 10 comprised of a filter body
12 according to FIG. 5. The filter body 12 is in this context
provided with a first open or closed end disk 16 arranged at an end
face 15 and a second end disk 18 at the opposite end face 17 that
effect an additional reinforcement of the filter element 10 and
also, as elastic elements (they are comprised usually of
polyurethane form or an elastomer), enable installation and
clamping of the filter element 10 in a housing. Moreover, it has a
support tube 14 that is concentric to the longitudinal axis L and
extends between the first and second end disks 16, 18. The first
end disk 16 has a radial seal 26 for sealing relative to a
housing.
[0052] In FIG. 8 a longitudinal section of a filter element 10
according to FIG. 7 is illustrated. The section through the filter
body 12 that is positioned between the two end discs 16, 18 that
may be comprised e.g. of injection-molded polyurethane or elastomer
has embossments 64 at regular spacings relative to each other. The
embossments 64 are embodied as recesses in the filter medium 56.
Also provided are strips or threads of a securing coil 66 applied
on the filter medium 56. In this way, a significant reinforcement
of the filter body 12 even in case of introduction of some moisture
and in case of great temperature fluctuations of the filtered air
is provided.
[0053] FIG. 9 shows an enlarged view of a part of the longitudinal
section of the filter element 10 according to FIG. 7. In this
illustration, the recesses of the embossments 64 as well as the
applied threads of the securing coil 66 can be seen more
clearly.
[0054] While specific embodiments of the invention have been shown
and described in detail to illustrate the inventive principles, it
will be understood that the invention may be embodied otherwise
without departing from such principles.
* * * * *