U.S. patent number RE37,165 [Application Number 09/370,379] was granted by the patent office on 2001-05-08 for fuel filter assembly.
This patent grant is currently assigned to Davco Manufacturing L.L.C.. Invention is credited to Leland L. Davis.
United States Patent |
RE37,165 |
Davis |
May 8, 2001 |
Fuel filter assembly
Abstract
A fuel filter assembly that provides a constant level of least
restricted fuel flow through the fuel filter assembly during the
useful life of the filter media by utilizing the least possible
amount of filter media to provide the least possible pressure
differential over the filter media while also providing a constant
level of fuel additive by exposing an amount proportional to the
filter media required for the least possible restricted fuel flow.
The fuel filter assembly utilizes a vertically upward housing that
houses a filter media and a fuel additive. The fuel level slowly
rises in the housing as the filter media becomes obstructed with
contaminants and as the fuel additive dissolves over the life of
the filter media. The top portion of the housing is made of a
transparent material so that the level of fuel may be easily
determined, thereby allowing for an accurate and simple assessment
of the useful life of the filter media and the fuel additive. The
housing also provides a multi-purpose aperture provided in the top
of the housing to provide for removal and/or replacement of the
fuel additive and venting and priming of the housing. The filter
media and fuel additive are entirely fabricated from combustible
materials so that both may be easily discarded without cost and
environmental concerns.
Inventors: |
Davis; Leland L. (San Antonio,
TX) |
Assignee: |
Davco Manufacturing L.L.C.
(Saline, MI)
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Family
ID: |
22738040 |
Appl.
No.: |
09/370,379 |
Filed: |
August 9, 1999 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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199555 |
Feb 22, 1994 |
5507942 |
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Reissue of: |
565808 |
Nov 30, 1995 |
05766449 |
Jun 16, 1998 |
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Current U.S.
Class: |
210/86; 210/111;
210/416.4; 210/440; 210/442; 210/443; 210/94 |
Current CPC
Class: |
C10L
10/00 (20130101); B01D 29/15 (20130101); F02M
25/00 (20130101); B01D 27/10 (20130101); F02M
37/32 (20190101); C10L 1/10 (20130101); B01D
37/025 (20130101); B01D 17/10 (20130101); C10L
1/10 (20130101); C10L 1/1691 (20130101); C10L
1/1691 (20130101); B01D 2201/309 (20130101); F02M
37/24 (20190101) |
Current International
Class: |
B01D
29/13 (20060101); C10L 1/10 (20060101); B01D
37/00 (20060101); B01D 37/02 (20060101); B01D
29/15 (20060101); C10L 10/00 (20060101); F02M
25/00 (20060101); F02M 37/22 (20060101); C10L
1/16 (20060101); B01D 027/10 (); B01D
035/143 () |
Field of
Search: |
;210/86,94,109,111,116,440,442,443,416.4 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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WO 86/00242 |
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Jan 1986 |
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WO |
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WO 93/01874 |
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Feb 1993 |
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WO |
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Primary Examiner: Solis; Erick R.
Attorney, Agent or Firm: Young & Basile, P.C.
Parent Case Text
This application is a continuation of application Ser. No.
08/199,555, filed on Feb. 22, 1994 now U.S. Pat. No. 5,507,942.
Claims
What is claimed is: .[.
1. A fuel filter assembly comprising:
a vertical housing having a fuel inlet for communicating a fuel
into said housing and a fuel outlet for communicating fuel
downstream of said housing;
means, disposed within said housing and between said fuel inlet and
said fuel outlet for filtering said fuel; and
means for self-adjusting a level of said fuel within said housing
wherein said fuel has inherent properties necessary to respond to a
pressure differential across said filtering means that is in
communication with said fuel such that said level of said fuel
progressively changes to communicate with additional surface area
of said filtering means and to maintain a substantially constant
pressure across said filtering means..]. .[.
2. The fuel filter assembly as stated in claim 1, wherein said
filtering means comprises:
a hydrophobic filter media that prohibits the passage of water
through said filter media..].
3. .[.The.]. .Iadd.A .Iaddend.fuel filter assembly .[.as stated in
claim 1, further.]. comprising:
.Iadd.a vertical housing having a fuel inlet for communicating a
fuel into said housing and a fuel outlet for communicating fuel
downstream of said housing;
means, disposed within said housing and between said fuel inlet and
said fuel outlet, for filtering said fuel;
means for self-adjusting a level of said fuel within said housing
wherein said fuel has inherent properties necessary to respond to a
pressure differential across said filtering means that is in
communication with said fuel such that said level of said fuel
progressively changes to communicate with additional surface area
of said filtering means and to maintain a substantially constant
pressure across said filter means; and .Iaddend.
said housing having a transparent portion for viewing said level of
said fuel and determining the useful life of said filtering
means.
4. A fuel filter assembly comprising:
a vertical housing having a fuel inlet for communicating a fuel
into said housing and a fuel outlet for communicating fuel
downstream of said housing;
means, disposed within said housing and between said fuel inlet and
said outlet, for filtering said fuel;
means for self-adjusting the level of said fuel within said housing
wherein said fuel has inherent properties necessary to respond to a
pressure differential across said filtering means that is in
communication with said fuel such that said level of said fuel
progressively changes to communicate with additional surface area
of said filtering means;
said housing having an interior portion; and
means for accessing an unfiltered side of said filtering means in
said interior portion to vent said housing and drain said fuel from
said housing and to prime said fuel filter assembly by introducing
said fuel directly into said unfiltered side of said housing
through said accessing means.
5. The fuel filter assembly as stated in claim 4, wherein said
housing comprises:
a top portion; and
a bottom portion releasably connected to said top portion, and said
bottom portion having a recessed well for holding and containing
excess fuel when said housing means is vented and said top portion
is removed so that excess fuel does not escape said bottom portion
of said housing.
6. The fuel filter assembly stated in claim 5, farther
comprising:
said fuel inlet opening into said bottom portion of said housing at
a horizontal level below said filtering means for communicating
fuel into said bottom portion and forming said level of said fuel
within said housing.
7. The fuel filter assembly stated in claim 5, wherein said
accessing means further comprises:
a threaded aperture extending through said top portion of said
housing and in communication with said unfiltered side of said
filtering means; and
cap means for detachably closing said threaded aperture to form an
enclosure.
8. A fuel filter assembly comprising:
an enclosed cylindrical housing extending vertically upward, and
said housing having a top portion and a bottom portion;
said bottom portion of said housing having a subfloor, a floor, and
an annular side wall integral with and extending vertically upward
from said floor, and said subfloor mounted substantially parallel
and vertically above said floor and having a plurality of apertures
extending therethrough for providing a non-turbulent, even flow of
fuel into said housing;
a fuel outlet disposed within said bottom portion and rising
vertically above said side wall, and said fuel outlet having a
shoulder extending radially outward above said floor;
a fuel inlet disposed within said bottom portion of said housing
and communicating fuel into said housing through said floor to form
a level of fuel within said housing;
a fuel filter canister having a filter media formed in a hollow
cylindrical configuration, and said fuel filter canister disposed
vertically upright within said housing and seated on said shoulder
of said fuel outlet wherein said fuel outlet is disposed within
said hollow cylindrical configuration of said filter media; and
said level of said fuel self-adjusting within said housing in
response to the pressure differential across said filter media that
is in communication with said fuel such that said level of said
fuel progressively rises to communicate with additional surface
area of said filter media.
9. The fuel filter assembly as stated in claim 8, further
comprising:
said top portion of said housing fabricated from a transparent
material for viewing said level of said fuel to determine the
useful life of said filter media.
10. The fuel filter assembly as stated in claim 8, wherein said
filter media comprises:
a hydrophobic filter media that prohibits the passage of water
through said filter media.
11. The fuel filter assembly stated in claim 8, further
comprising:
said top portion of said housing having a threaded aperture
extending therethrough and in communication with an unfiltered side
of said fuel filter canister; and
a cap threadingly received in said threaded aperture for detachably
closing said aperture in said top portion to form an enclosure when
said fuel filter assembly is in use and for opening said aperture
for venting said housing and draining said fuel from said housing
and priming said fuel filter assembly by introducing fuel directly
into said housing through said aperture.
12. The fuel filter assembly as stated in claim 11, further
comprising:
said top portion of said housing releasably connected to said
bottom portion of said housing, and said bottom portion having a
recessed well defined by said floor and said annular side wall for
holding and containing excess fuel when said housing is vented and
said top portion is removed from said bottom portion so that excess
fuel does not escape through said fuel outlet.
13. An improved fuel filter assembly having a housing with a bottom
portion, and a top portion, an inlet for receiving a fluid, and an
outlet for communicating a filtered fluid, a filter media housed
within said housing for filtering said fluid between said inlet and
said outlet, the improvement comprising:
means for self-adjusting a level of said fluid within said housing
wherein said fluid has inherent properties necessary to respond to
a pressure differential across said filter media that is in
communication with said fluid such that said level of said fluid
progressively changes to communicate with additional surface area
of said filter media;
said housing having an interior portion; and
means for accessing an unfiltered side of said filter media in said
housing to vent said housing, drain fluid from said housing, and
prime said fuel filter assembly by introducing said fluid directly
into said unfiltered side of said housing through said accessing
means.
14. The improved fuel filter assembly as stated in claim 13,
wherein the improvement comprises:
a hydrophobic filter media that prohibits the passage of water
through said filter media.
15. The improved fuel filter assembly as stated in claim 13, the
improvement comprising:
said housing having a transparent portion for viewing said level of
said fluid for determining the useful life of said filter
media.
16. An improved fuel filter assembly having a housing with a bottom
portion, and a top portion, an inlet for receiving a fluid, and an
outlet for communicating a filtered fluid, a filter media housed
within said housing for filtering said fluid between said inlet and
said outlet, the improvement comprising:
means for self-adjusting a level of said fluid within said housing
wherein said fluid has inherent properties necessary to respond to
a pressure differential across the filter media that is in
communication with said fluid such that said level of said fluid
progressively changes to communicate with additional surface area
of said filter media; and
said bottom portion of said housing having a subfloor, a floor, and
an annular side wall integral with and extending vertically upward
from said floor, and said subfloor mounted substantially parallel
and vertically above said floor and having a plurality of apertures
extending therethrough for providing a non-turbulent, even flow of
fluid into said housing.
17. The improved fuel filter assembly as stated in claim 16, the
improvement comprising:
said housing having a transparent portion for viewing said level of
said fluid for determining the useful life of said filtering
means.
18. A fuel filter assembly comprising:
a housing for containing a filter media and communicating a fuel
through said filter media;
means for self-adjusting the level of said fuel within said housing
such that said level of said fuel progressively changes to
communicate with additional surface area of said filter media;
means for accessing an unfiltered side of said filter media in said
housing to vent said housing and drain said fuel from said housing
and to prime said fuel filter assembly by introducing fuel directly
into said unfiltered side of said housing through said accessing
means; and
said housing having a transparent portion for viewing said level of
said fuel for determining the useful life of said filter media.
Description
FIELD OF THE INVENTION
The present invention relates to fuel filter assemblies and more
particularly, to a fuel filter assembly that provides a constant
level of restricted fuel flow through the fuel filter assembly
during the useful life of the filter media by utilizing a minimum
amount of filter media to obtain the least possible restricted fuel
flow while providing a fuel additive whose addition is
proportionally related to the amount of filter media required for
least possible restricted fuel flow.
BACKGROUND OF THE INVENTION
It is well known to utilize fuel filter assemblies to filter fuel
for a combustible engine of a motor vehicle. Such fuel filter
assemblies typically comprise a sideways or downwardly mounted
canister having a paper filter media enclosed in the canister. The
fuel enters and fills the canister so that all of the filter media
is doused with fuel as the fuel passes through the paper filter
media and exits the canister to travel to the engine. Various
contaminants are filtered from the fuel that would degrade the
performance of the engine if left within the fuel. After a certain
amount of filtration, the contaminants begin to obstruct the filter
media and restrict fuel flow through the filter media. Since the
entire filter media is doused in fuel, fuel flow restriction
steadily increases during the useful life of the filter media.
Restricted fuel flow degrades the performance of the engine, and if
unattended, could lead to continued degradation of performance as
well as mechanical and structural failure of the engine's
components.
As fuel flows through the filter media, a pressure differential
occurs across the filter media as the unfiltered side of the filter
media realizes a higher pressure from the fuel than does the
filtered side. When the filter media is unobstructed, the pressure
differential is at a minimum since fuel is relatively free to flow
through the unobstructed filter media. When the filter media
becomes obstructed, the pressure differential increases as pressure
increases on the unfiltered side of the filter media to force the
fuel through the obstructed filter media. This can lead to
contaminants being forced through the filter media, essentially,
tearing the filter media. Typically, when the useful life of the
filter media has expired, the filter media is replaced, although no
method or apparatus is provided that accurately determines when the
filter media should be replaced. It is well known to provide
transparent canisters to view the condition of the filter media,
but there is still no indication as to how obstructed the filter
media is or to what extent fuel flow is being restricted.
With the advent of electronically controlled fuel injection engine
systems, fuel filter systems are playing an ever increasingly
important role in reducing and eliminating contaminants in fuel.
Such fuel injection systems utilize extremely high injection
pressures and, therefore, are extremely sensitive to restrictive
fuel flows and various contaminants.
There are many known contaminants which will effect the performance
of a fuel injection system. Due to the high injection pressures of
fuel injection systems, minute quantities of water damage injectors
by destroying internal lubrication and by causing galling and
erosion of spray holes and tips. Also, such fuel injector systems
now expose fuel to repeated heating and cooling cycles as fuel
flows through cylinder heads and around fuel injectors of engines.
This creates water condensation in fuel tanks as well as microbial
growths and polymerization of fuel components. All of these
contaminants contribute to a shortened fuel filter life as the
contaminants begin to obstruct the filter media and restrict fuel
flow.
As mentioned earlier, the problem of an obstructed fuel filter is
typically remedied by replacing the filter media, but since the
contamination formation rate in the fuel varies with temperatures,
crude stocks and time, it is not easy to determine the status of
serviceability or the remaining useful life of a conventional fuel
filter. As the demand on fuel filter systems to filter such a wide
range of contaminants increases, the price of such fuel filters
increase, and therefore, it is not desirable to prematurely replace
a fuel filter. A high rate of fuel filter replacement creates
problems with fuel filter disposal, disposition cost of used
filters, and environmental considerations. Also, when servicing
fuel filter assemblies, concern must be given to fuel that is still
within the fuel filter assembly after venting the assembly so that
such fuel does not escape into the environment or be allowed to
exit into the fuel outlet without having been filtered and
treated.
As previously described, the heating and cooling cycles of fuel
involved in fuel injector systems may promote the growth of
microorganisms such as bacteria and fungi. Such microorganisms
create problems of sludge, clogged fuel filters and corrosive
by-products that damage storage tanks, fuel lines, filters,
injection pumps, injectors, burners, governors and other control
mechanisms. Microorganisms deplete special additives for gasoline,
gasohols and alternative fuels needed for octane and cetane
improvement as well as depleting other chemicals that improve
performance or comply with environmental and clean air
requirements.
It is well known to douse fuel tanks or bulk storage tank
reservoirs with fuel additives when microorganic infections are
found. Generally, once the microorganisms are found, a great amount
of damage and contamination has occurred resulting in expensive
maintenance, replacement of components and filters as well as the
stoppage of furnaces and engines. Several attempts have been made
to provide a fuel filter that not only filters fuel but also
provides a fuel additive for destroying microorganisms in the fuel.
Such fuel additives are typically released manually and have no
means by which to slowly release the fuel additive or release the
fuel additive when microorganisms have reached an unacceptable
level. Also, none of these attempts provide a method or means by
which to replace the fuel additive or accurately gage the need to
replace the fuel additive.
It would be desirable to provide a fuel filter assembly that
provided a constant level of restricted fuel flow through the fuel
filter assembly during the useful life of the filter media by
utilizing a minimum amount of filter media to obtain the least
possible restricted fuel flow while also providing a fuel additive
whose addition is proportionally related to the amount of filter
media required to provide the lowest possible level of restricted
fuel flow. It would also be desirable to provide a fuel filter
system that provided an accurate and simple means by which to gage
the useful life of the filter media and the fuel additive. In
addition, it would be desirable to provide a multi-purpose access
means for easily removing and/or replacing the fuel additive, for
venting the fuel filter assembly, and for priming the fuel filter
assembly without disassembling the fuel filter assembly. It would
also be desirable to provide a means for collecting excess fuel
upon venting and draining the fuel from the fuel filter so that
fuel does not escape the fuel filter housing or exit unfiltered and
untreated into the fuel outlet. Lastly, it would also be desirable
to provide a fuel filter media and fuel additive that could be
discarded without having cost and environmental concerns.
SUMMARY OF THE INVENTION
The present invention provides a fuel filter assembly that provides
a constant level of restricted fuel flow through a filter media
during the useful life of the filter media by utilizing a minimum
amount of filter media to obtain the least possible restricted fuel
flow while providing a fuel additive whose addition is
proportionally related to the amount of filter media required for
the least possible restricted fuel flow. The present invention also
provides a means by which to accurately assess the useful life of
the filter media and fuel additive so that proper and efficient
replacement of the filter media and fuel additive will occur. In
addition, the present invention provides a multi-purpose access for
removing and/or replacing the fuel additive without the need for
disassembling the fuel filter assembly, for providing a means for
venting the fuel filter assembly to drain the fuel from the fuel
filter assembly, and for providing access to prime the fuel filter
assembly directly with fuel. A well is provided in the fuel filter
assembly for collecting excess fuel when the fuel filter assembly
is vented so that fuel does not escape into the environment or into
the engine unfiltered and untreated. Replacement parts for the fuel
filter assembly are entirely combustible so that the replacement
portions of the fuel filter assembly can be discarded at a minimal
expense and concern.
In the preferred form, the present invention provides a vertically
upright fuel filter assembly having an enclosed housing. A fuel
filter canister is formed by folding a hydrophobic filter media
back and forth in a circular direction to form a hollow cylinder
housed within the housing. Two end caps support the filter media at
each of its ends. A fuel additive is formed into a hollow
cylindrical geometry, and a wax substrate is mixed with the fuel
additive to support the fuel additive in a vertical orientation and
to slowly release the fuel additive upon the wax substrate
dissolving. A means for supporting the fuel additive is provided to
retain the fuel additive in a stationary vertical position when the
bottom portion of the fuel additive begins to dissolve. The fuel
additive is housed within the hollow cylinder of the fuel filter
canister. The housing has a bottom portion that provides a fuel
inlet and a fuel outlet for the entrance and exit, respectively, of
fuel.
As fuel enters the housing through the inlet, the fuel level rests
when the fuel flow demand is met by utilizing the lowest possible
pressure differential across the filter media while utilizing the
least amount of filter media to obtain the least possible
restricted fuel flow. This results in the fuel level resting at a
level where there is enough unobstructed filter media to provide
the least possible restriction to fuel flow.
The fuel additive is fuel soluble and slowly dissolves into the
fuel, destroying microorganisms that may exist. Upon the filter
media becoming obstructed with contaminants, the fuel level rises
searching for the least possible restricted fuel flow or the lowest
possible pressure differential across the filter media while
utilizing the least possible amount of filter media. When the fuel
level rises, it also contacts a higher level on the fuel additive.
Since the portion of the fuel additive submerged in fuel is
constantly dissolving into the fuel, the rising level of the fuel
dissolves additional fuel additive to replace the fuel additive
that has already dissolved. This provides a substantially constant
level of fuel additive in the fuel over the life of the filter
media as the remainder of fuel additive is proportional to the
remainder of the unobstructed filter media. If the level of
microorganisms grow, the filter media will become increasingly
obstructed, the fuel level will rise toward the unobstructed filter
media, and more fuel additive will dissolve into the fuel to
destroy the growing microorganisms. When the fuel level reaches the
top of the housing, the filter media is entirely obstructed, and
the fuel additive is completely dissolved. The housing of the fuel
filter assembly is fabricated from a transparent material to allow
the useful life of the filter media and fuel additive to be
accurately and easily determined by simply determining the fuel
level in the housing.
In another form of the invention, the fuel filter canister
comprises the filter media, end caps, wax substrate, fuel additive
and means for supporting the fuel additive. All of these elements
are fabricated from combustible materials to provide for
replacement and discardment of these parts without excessive cost
or environmental concerns.
In yet another form of the invention, the top of the housing has a
multi-purpose aperture with a mating cap for releasingly and
sealingly closing the aperture. When the cap is secured to the
housing, the aperture is closed, and the fuel filter assembly is
ready for use. When the cap is detached from the housing, and the
aperture is open, the fuel additive may be removed and/or replaced
with a new fuel additive without the need for disassembling the
fuel filter assembly. The aperture may also be opened to vent the
housing of the fuel filter assembly and allow the fuel to drain
from the housing to conduct maintenance on the vehicle or the fuel
filter assembly. The aperture may also be utilized to prime the
fuel filter assembly by directly introducing fuel into the housing
of the fuel filter assembly via the aperture.
In an additional form of the invention, the housing of the fuel
filter assembly comprises a top portion and a bottom portion that
are detachably and sealingly connected. The bottom portion provides
a well for collecting and holding excess fuel that has drained from
venting the housing. After the fuel has drained from the housing,
the top portion may be detached from the bottom portion without
spilling fuel into the surrounding environment and without having
unfiltered and untreated fuel escape into the outlet of the fuel
filter assembly and travel to the engine.
To this end, the objects of the present invention are to provide a
new and improved fuel filter assembly that provides a constant
level of least restricted fuel flow during the useful life of the
filter media by utilizing the least possible amount of filter media
to obtain the least possible restricted fuel flow while providing a
fuel additive whose addition is proportionally related to the
amount of filter media required for least possible restricted fuel
flow; to provide a new and improved fuel filter assembly that
fabricates all replaceable parts of the fuel filter assembly from
combustible material so that the replaceable parts may be discarded
without cost and environmental concerns; to provide a new and
improved fuel filter system that provides a multi-purpose access
for removing and/or replacing the fuel additive, for venting the
housing of the fuel filter assembly, and for priming the fuel
filter assembly by introducing fuel directly into the housing of
the fuel filter assembly without having to disassemble the fuel
filter assembly; to provide a new and improved fuel filter assembly
that provides a well for collecting and holding excess fuel from
the housing of said fuel filter assembly upon the housing being
vented so that said excess fuel does not escape into the
surrounding environment or escape into the fuel outlet before the
fuel is filtered and treated; and to provide a new and improved
fuel filter assembly that provides an accurate and simple means by
which to determine the remaining useful life of the filter media
and fuel additive without having to disassemble the fuel filter
assembly.
Other objects, advantages and applications of the present invention
will become apparent to those skilled in the art when the following
description of the best mode contemplated for practicing the
invention is read in conjunction with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The description herein makes reference to the accompanying drawings
wherein like reference numerals refer to like parts throughout the
several views, and wherein:
FIG. 1 is a perspective view with some parts cut-away showing the
filter media and the fuel additive housed within a transparent top
portion of the fuel filter assembly;
FIG. 2 is an enlarged section view of the fuel filter assembly with
some parts exploded showing the top portion and the bottom portion
of the fuel filter assembly and showing the filter media and the
fuel additive housed within the fuel filter assembly; and
FIGS. 3A-C are schematic diagrams showing the progression of the
fuel level and fuel additive level during different intervals of
the useful life of the filter media and the fuel additive.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, the present invention will now be
described in detail with reference to the preferred embodiment.
FIGS. 1 and 2 show the fuel filter assembly 10 in its preferred
form. The fuel filter assembly 10 is mounted vertically upright and
provides a closed housing 12 having a fuel inlet 14 that is in
communication with a fuel storage tank (not shown) and a fuel
outlet 16 that is in communication with an engine (not shown) of a
motor vehicle (not shown). A filter media 18 is housed within the
housing 12, and a fuel additive 20 is contained within the filter
media 18. The fuel inlet 14 delivers fuel (not shown) into the
housing 12 so that the fuel passes through the filter media 18 and
contacts the fuel additive 20. The fuel additive 20 is soluble in
fuel and dissolves in the fuel. The filtered and treated fuel exits
through the fuel outlet 16 and flows to the engine.
To allow for maintenance of the fuel filter assembly 10, a simple
means for disassembling and reassembling the fuel filter assembly
10 is provided. As seen in FIG. 2, the housing 12 of the fuel
filter assembly 10 comprises a top portion 22 and a bottom portion
24. The top portion 22 is substantially cylindrical with a
substantially u-shaped cross section. The top portion 22 has a
closed end 26 and an open end 28 with an aperture 30 extending
through the closed end 26. The open end 28 of the top portion 22
has an L-shaped flange 32 extending outward from the open end 28 of
the top portion 22, as seen in FIGS. 1 and 2. The horizontal
portion 34 of the L-shaped flange 32 is integral with and
substantially perpendicular to the top portion 22 of the housing
12. The vertical portion 36 of the L-shaped flange 32 is integral
with and extends downward from the horizontal portion 34. The
vertical portion 36 of the L-shaped flange 32 has an inner diameter
that provides an interior threaded region 38.
As seen in FIG. 2, the bottom portion 24 of the housing 12 is also
cylindrical and has a circumferential wall 40 that is integral with
and extends upward from the bottom portion 24. The outside diameter
of the wall 40 has a threaded region 42 that mates with the
interior threaded region 38 of the L-shaped flange 32 provided on
the top portion 22 of the housing 12. The horizontal portion 34 of
the L-shaped flange 32 has a bottom surface 44 that abuts a top
surface 46 of the wall 40 of the bottom portion 24 when the top
portion 22 is threaded onto the bottom portion 24. A parting line
48 is formed between the bottom surface 44 of the L-shaped flange
32 and the top surface 46 of the wall 40. The bottom surface 44 of
the horizontal portion 34 of the L-shaped flange 32 provides an
annular groove 50 for housing an annular deformable seal 52. The
deformable seal 52 is seated in the groove 50 and extends outward
from the groove 50. The deformable annular seal 52 deforms against
the top surface 46 of the upwardly extending wall 40 of the bottom
portion 24 so that the parting line 48 created between the abutting
surfaces 44, 46 of the top portion 22 and the bottom portion 24,
respectively, is sealed to prevent any fuel from leaking through
the parting line 48. The threading and sealing engagement of the
top portion 22 and the bottom portion 24 allows the housing 12 to
be releasingly and sealingly closed for the filtering and treating
of fuel.
To provide for a non-turbulent, even flow of fuel into the housing
12, the bottom portion 24 of the housing 12 has a substantially
flat floor 54 with the wall 40 rising vertically from and extending
circumferentially around the floor 54. The fuel inlet 14 rises
vertically through the bottom portion 24 and through the floor 54
to deliver fuel to the housing 12. A substantially flat subfloor 56
with a plurality of apertures (not shown) therethrough lies
slightly above and substantially parallel to the floor 54 of the
bottom portion 24. The subfloor 56 is supported by
circumferentially chamfered corners 58 of the floor 54. A reservoir
60 is created between the subfloor 56 and the floor 54 for incoming
fuel supplied by the fuel inlet 14. Fuel fills the reservoir 60 and
provides a fuel level that rises and flows evenly into the housing
12 through the apertures provided in the subfloor 56.
In order to provide a constant level of least possible fuel flow
restriction through the fuel filter assembly 10 over the life of
the filter media 18 while utilizing the least possible amount of
filter media 18, the filter media 18 is housed vertically in the
housing 12 so that the lower portions of the filter media 18 become
obstructed first before the fuel level rises and utilizes
unobstructed upper portions of the filter media 18. A filter
canister 62 provides the filter media 18 which is folded back and
forth in a circular fashion so that a hollow cylinder is formed. In
another embodiment, the filter media 18 may be continually rolled
or wound about a vertical axis or reference cylinder to form a
hollow cylinder (not shown) having substantially concentric layers
of filter media 18 layered adjacent one another. Two end caps 64,
66 support the filter media 18 at its ends, and each end cap 64, 66
has an aperture 68, 70, respectively, extending therethrough that
are in common alignment with the hollow cylinder of the filter
media 18. The filter media 18 is fabricated from a paper based
material, but any other suitable material, such as fiberglass,
plastics, etc., may be utilized to provide the proper filtering
characteristics while also being combustible for efficient
disposal. In another embodiment, the filter media 18 comprises a
hydrophobic filter media that prohibits the passage of water
through the filter media 18. This prevents any water from passing
through the fuel filter assembly 10 and effecting the performance
of the engine or damaging fuel injection mechanisms of the
engine.
In order to provide a substantially constant level of fuel additive
whose addition is proportionally related to the amount of filter
media 18 required for the least possible restricted fuel flow, the
fuel additive 20 extends vertically upward within the filter
canister 62, as seen in FIGS. 1 and 2. The fuel additive 20 is
formed into a hollow cylinder by encapsulating or mixing the fuel
additive 20 with a wax substrate to provide the proper release of
the fuel additive 20 into the fuel. The wax substrate is formulated
from a high purity, high melting point paraffin that provides clean
burning characteristics without adversely compromising the
performance or wear characteristics of the engine. A means for
supporting the fuel additive 20 retains the undissolved portion of
the fuel additive 20 in its vertical position when the bottom of
the fuel additive 20 dissolves.
As seen in FIG. 1 and 2, the means for supporting the fuel additive
20 may be an outer reinforcement 72 that is adhered to the outside
surface 74 of the fuel additive 20. The outer reinforcement 72 has
a plurality of apertures 76 extending therethrough to allow the
fuel additive 20 to be directly exposed to the fuel. The outer
reinforcement 72 may be made of a paper based material or a molded
plastisol/epoxy that does not dissolve in fuel yet is combustible
for efficient disposal. In another embodiment, the supporting means
may have an inner skeleton (not shown) fabricated from a thin wire.
In an additional embodiment, spring or tension clips (not shown)
may be utilized as the supporting means to retain the ends of the
fuel additive to the fuel filter canister 62. In yet another
embodiment, the supporting means may have a modified inner core
support (not shown) that would contain the fuel additive in a
liquid or solid phase. The inner core support utilizes separate
compartments or levels so that each compartment or level would
dissolve individually as the fuel level continued to rise.
The fuel additive 20 is housed within the filter canister 62 so
that the fuel is exposed to the fuel additive 20 after passing
through the filter media 18. As seen in FIG. 2, the fuel outlet 16
provides a hollow cylinder rising vertically upward through the
bottom portion 24 of the housing 12 to a vertical level above the
wall 40 of the bottom portion 24. An opening 80 is provided in the
top end of the hollow cylinder of the fuel outlet 16 to allow the
fuel to travel to the engine. In another embodiment, the top end of
the fuel outlet 16 is closed, and a plurality of apertures (not
shown) extend laterally through the hollow cylinder of the fuel
outlet 16 at a level above the wall 40 of the bottom portion 24. A
shoulder 78 is provided on the fuel outlet 16 that extends
horizontally outward from the hollow cylinder of the fuel outlet
16. The shoulder 78 rises to a vertical level higher than the
subfloor 56 of the bottom portion 24 and lower than the opening 80
of the fuel outlet 16. The bottom portion of the fuel additive 20
telescopically slides over the fuel outlet 16, and a bottom surface
82 of the fuel additive 20 abuts the shoulder 78 of the fuel outlet
16. The filter canister 62 also has its bottom end cap 66 abutting
a portion of the shoulder 78 of the fuel outlet 16 so that the
filter canister 62 does not cover the apertures in the subfloor 56
and restrict the flow of fuel coming through the fuel inlet 14. By
having the fuel outlet 16 within and directly under the fuel
additive 20, the fuel is ensured of being filtered and treated
before exiting the fuel filter assembly 10.
To prohibit movement of the filter canister 62 within the housing
12, an axial compression spring 84 is seated between the top end
cap 64 of the filter canister 62 and the inside surface 86 of the
closed end 26 of the top portion 22 of the housing 12. The spring
84 applies a compressive force downward on the top end cap 64 of
the filter canister 62 so that the filter canister 62 remains
securely seated on the shoulder 78 of the fuel outlet 16 thereby
prohibiting movement of the filter canister 62.
In a preferred form, the fuel additive 20 comprises a microbicide
that is compatible with combustion systems and fuels and which is
more soluble in fuel than water. Microbicides that are more soluble
in water than in fuel run the risk of having a significant quantity
of water exist in the fuel or storage tanks and having these
microbicides partition in the water and adversely effect the pH
levels which may cause damage to fuel tanks or fuel components. A
microbicide, like the one sold under the trademark "Procide" by
Davco Manufacturing Corporation, is only slightly soluble in water
and will not adversely effect pH levels. As previously described,
such a microbicide is encapsulated in the wax substrate, paraffin,
which has a high melting point and a clean burning characteristic
and will assure proper release of the microbicide or the fuel
additive 20 without compromising exhaust gas emissions and without
unduly releasing an excessive amount of fuel additive 20 that may
adversely effect engine and fuel components. It should be noted
that the present invention is not limited to the fuel additive 20
being a microbicide, but rather, the fuel additive 20 may also
comprise cetane improvers, antioxidants, stabilizers, combustion
improvers and emission reducers depending on the objectives and
application of the fuel filter system 10.
In order to gain access to the housing 12 without having to
disassemble the fuel filter assembly 10, a multi-purpose aperture
30 is provided in the closed end 26 of the top portion 22 of the
housing 12. A flange 88 integral with and extending downward from
the closed end 26 of the top portion 22 has a threaded region 90 on
an inside surface of the flange 88 that defines the aperture 30. A
cap 92 having a cylindrical head 94 and a neck portion 96 integral
therewith provides a threaded region 98 on an outside surface of
the neck portion 96. The threaded region 98 of the neck portion 96
threadingly mates with the threaded region 90 of the flange 88 of
the closed end 26 of the top portion 22 to secure the cap 92 to the
top portion 22 and to close the aperture 30. A deformable annular
seal 100 is provided between a bottom surface 102 of the head 94 of
the cap 92 and an outside surface 104 of the closed end 26 of the
top portion 22, so that when the cap 92 is secured to the top
portion 22, the adjoining surfaces 102, 104, of the cap 92 and top
portion 22, respectively, seal to prevent any fuel from leaking
through the aperture 30.
To remove and/or replace the fuel additive 20 with a different type
of fuel additive or a fully undissolved fuel additive should there
be a sudden increase in the growth of microorganisms, the aperture
30 must be large enough for the fuel additive 20 to be removed from
and replaced into the housing 12. The aperture 30 may also be
opened for the purpose of venting the housing 12 of the fuel filter
assembly 10 so that the fuel contained in the housing 12 will drain
back into the system. It is necessary to vent the housing 12 when
removing and/or replacing the fuel additive 20, when replacing the
filter media 18 and when conducting any other maintenance
associated with the fuel filter assembly 10. When such maintenance
is completed, the aperture 30 may also be utilized as an access for
priming the fuel filter assembly 10 by adding fuel directly into
the housing 12 through the aperture 30. To close the aperture 30,
the cap 92 is threaded into the aperture 30 and tightly secured to
the top portion 22 of the housing 12 so that the housing 12 is
closed, and the fuel filter assembly 10 is ready for use.
When the aperture 30 is opened to vent the housing 12, and the top
portion 22 is removed from the bottom portion 24 of the housing 12,
fuel may escape into the surrounding environment, and unfiltered,
untreated fuel may escape through the fuel outlet 16 and into the
engine. To prevent such occurrences, a well 106 is provided in the
bottom portion 24 of the housing 12 and is defined by the wall 40,
the floor 54, and the fuel outlet 16. The vertical level of the
fuel outlet 16 is higher than the vertical height of the wall 40 to
ensure that unfiltered, untreated fuel in the well 106 does not
spill over into the fuel outlet 16.
When the fuel filter assembly 10 is in use, the top portion 22 of
the housing 12 is secured and sealed to the bottom portion 24 of
the housing 12, and the cap 92 is secured and sealed to the top
portion 22 of the housing 12 to close the aperture 30 and provide a
closure for the housing 12. The fuel filter assembly 10 receives
fuel through the fuel inlet 14, and the fuel inlet 14 delivers the
fuel into the housing 12 between the housing 12 and the filter
media 18. The fuel level rises in the housing 12 only to a level
that will satisfy flow demand with the lowest possible pressure
differential across the filter media 18. This provides a filtering
arrangement that utilizes only as much of the filter media 18 as
necessary to achieve the least possible restriction of fuel flow
through the filter media 18. As the fuel passes through the filter
media 18, the fuel contacts the fuel additive 20 through the
apertures 76 provided in the outer reinforcement 72. Since the fuel
additive 20 is mounted in a vertical column with the filter media
18, the amount of fuel additive 20 exposed to the fuel is
proportional to the amount of filter media 18 exposed to obtain the
least possible restriction of fuel flow. Since the fuel additive 20
is soluble with the fuel, the fuel additive 20 slowly dissolves
into the fuel and then passes through the fuel outlet 16. By having
the release of fuel additive 20 correspond with the fuel level, the
fuel additive 20 is time released to provide a continuing supply of
fuel additive over the useful life of the filter media 18.
When the filter media 18 becomes obstructed and fuel flow demand is
not met, the fuel level in the housing 12 will rise so that the
fuel flow demand is satisfied by maintaining the lowest possible
pressure differential across the filter media 18 while utilizing
the least possible amount of filter media 18. In the case of the
fuel additive 20 being a microbicide, the contaminants may be
microbial growths, and therefore, when the fuel level rises, more
fuel additive 20 is exposed to the fuel, thereby destroying the
microbial growths and reducing the contaminants in the fuel.
As the filter media 18 becomes increasingly obstructed, the fuel
level continues to rise within the housing 12. By observing the
fuel level through the transparent top portion 22 of the housing
12, a determination as to the useful life of the filter media 18
and the fuel additive 20 can be easily ascertained. As seen in FIG.
3A, when the fuel level 108 is near the bottom of the housing 12,
the filter media 18 has its entire useful life available as the
filter media 18 is unobstructed, and only a small portion of the
fuel additive 20 has dissolved. As seen in FIG. 3B, when the fuel
level 108 is midway up the housing 12, substantially half of the
useful life of the filter media 18 remains. This corresponds to
substantially half of the filter media 18 being obstructed while
substantially half of the fuel additive 20 has dissolved. As seen
in FIG. 3C, when the fuel level 108 is at the top of the housing
12, only a small amount of useful life remains in the filter media
18. The filter media 18 has become almost completely obstructed,
and the fuel additive 20 may be completely dissolved. When the fuel
level 108 is observed at the top of the housing 12, as seen in FIG.
3C, the filter media 18 and fuel additive 20 are replaced.
In order to avoid environmental and cost concerns when replacing
and discarding the filter canister 62 and fuel additive 20, the
fuel canister 62 and fuel additive 20 are entirely fabricated from
combustible material. The filter canister 62 utilizes a paper
filter media 18 and molded plastisol/epoxy end caps 64, 66. The
fuel additive 20 is obviously combustible, and the wax substrate is
fabricated from a paraffin which is a hydrocarbon mixture with
clean burning characteristics. The outer reinforcement 72 of the
fuel additive is fabricated from a paper based material or a molded
plastisol/epoxy which are both combustible.
While the invention has been described in connection with what is
presently considered to be the most practical and preferred
embodiment, it is to be understood that the invention is not to be
limited to the disclosed embodiments but, on the contrary, is
intended to cover various modifications and equivalent arrangements
included within the spirit and scope of the appended claims, which
scope is to be accorded the broadest interpretation so as to
encompass all such modifications and equivalent structures as is
permitted under the law.
* * * * *