A CONTAMINANT CONTAINER Technical Field

This invention relates to a fuel filter having a contaminant container of the type that is commonly employed as a part of the fuel system of an internal combustion engine. "Fuel" as used herein refers to liquid fuel such as gasoline, diesel or other liquid fuels. When fuel is stored in a vessel, particularly a metal fuel tank wherein the temperature of the tank can readily change, it is common for water to collect in the fuel as a consequence of condensation. Water is immiscible with most fuels, including gasoline and diesel, and is a serious contaminant. Water can freeze in a fuel line and block the flow of fuel. Furthermore, water causes corrosion of metal parts of the fuel system.

For these reasons, it is desirable to remove water and other non-immiscible contaminants from fuel. To this end, others in the past have provided fuel filters that have a contaminant collection container positioned on the bottom of the fuel filter housing into which water and other non-immiscible contaminants can be collected.

As a specific example of a fuel filter of this type, reference may be had to U.S. Patent 4,740,299 entitled "Fuel Assembly With Threaded Collection Bowl". This patent discloses a fuel filter having a fuel inlet and outlet and a housing in which a filter element is removably positioned. Below the housing is a collection bowl. A collector ring is positioned within the housing and the fuel element rests on the collector ring. The collector ring has a

downwardly extending tubular portion with external threads that treadably receives the collection bowl. To provide flowage passageways from the interior of the filter housing to the collection bowl, the collection ring is provided with radially extending ribs. Thus, water or other contaminants flowing into the interior of the filter housing and exterior of the filter element may pass by gravity downwardly and flow between the upstanding ribs of the collector ring into the collection bowl.

The filter assembly as revealed in this patent introduces a potential problem in that turbulence of fuel flow through the filter is easily communicated between the interior of the filter housing and the collection bowl by the short, open passageways between upstanding ribs on the collector ring. An object of the present invention is to provide a fuel filter having improved communication with a contaminant container in such a way that any turbulence of fuel flow within the filter housing is isolated from the interior of the contaminant container.

The references cited in U.S. Patent 4,740,299 provide further background information as to prior art relating to the present invention. Disclosure of the Invention

A fuel filter having improved communication with a contaminant container has a body with a fuel inlet port and a fuel outlet port . Attached to the body is a housing with a cylindrical peripheral wall. A filter element is positioned within the housing, the filter element serving to separate the housing into a central fuel chamber and a peripheral fuel chamber. The

peripheral fuel chamber is disposed between the exterior of the filter element and the casing. The filter element is disposed intermediate the fuel inlet and fuel outlet ports to thereby place the filter element in the fuel flow path.

A support plate is positioned within the bottom of the housing. Secured exteriorly to the filter housing and below it is a contaminant container. The contaminant container may be transparent so that collected contaminant can be visually observed.

A spiral ledge is formed on the upper surface of the support plate. The bottom surface of the filter element rests on the spiral ledge . A flow channel is provided by the spiral ledge. The flow channel communicates the peripheral fuel chamber within the housing with the contaminant container. Fuel having contaminant, such as water, therein first enters the peripheral fuel chamber where water, by gravity, can separate out. Water collected in the bottom portion of the filter housing flows by way of the spiral contaminant channel into the collection vessel.

The spiral contaminant channel serves to substantially isolate the interior of the contaminant container from any turbulence occurring within the filter housing. That is, there are no short, direct passageways between the interior of the housing and the contaminant container. Instead, the spiral ledge provided on the support plate in the present invention provides a long, spiraled passageway communicating the interior of the filter housing with the contaminant container that permits the flow of contaminant therethrough but resists communication

of turbulence between the interior of the filter housing and the contaminant container. Description of the Drawings

The features of the invention, and its technical advantages, can be seen from the following description of the preferred embodiments together with the claims and the accompanying schematic drawings, in which:

Figure 1 is an elevational cross- sectional view of a fuel filter having improved communication with a contaminant container;

Figure 2 is an isometric view of the support plate employed in the fuel filter of Figure 1; Figure 3 is a top plan view of the support plate; and

Figure 4 is an elevational cross- sectional view of the support plate as taken along the line 4-4 of Figure 3. Description of the Preferred Embodiments

Figure 1 is a cross-sectional illustration of a preferred embodiment of the invention wherein the fuel filter having improved communication with a contaminant container is generally indicated by the numeral 10. The fuel filter is adapted to mount to a body 12 having a fuel inlet 14 and a fuel outlet 16. A centrally threaded passageway 18 receives a tubular coupling 20. Threadably attached to the tubular coupling 20 is a filter housing indicated generally by 22. The filter housing 22 includes a top plate 24 having a threaded central opening 26 that threadably receives the tubular coupling 20. Thus, the tubular coupling 20 provides means

for attachment of the filter housing 22. The top plate 24 includes provisions for a circumferential gasket 28 that engages the lower surface 30 of the body 12. The housing 22 includes a tubular wall

32 having an inwardly folded lower end 34.

Received within the filter housing 22 is a filter element 36 that has a perforated center tube 38. The filter element 36 has an upper end plate 40 with a tubular opening that receives the gasket 42 that sealably engages the exterior surface of the tubular coupling 20. The filter element 36 further has a lower end plate 44 that closes the lower end of the center tube 38. Surrounding the center tube 38 is a filter media having an external surface 46. The annular space between the exterior surface 46 of the filter element 36 and the interior of the housing tubular wall 22 provides a peripheral fuel chamber 48. Openings 50 in the top plate 24 provide communication between the fuel inlet 14 and the peripheral fuel chamber 48 so that fuel entering the fuel filter flows into the interior of the housing 22 to surround the exterior surface 46 of the filter element 36. Fuel is filtered as it migrates through the filter element 36 into the interior of the perforated center tube 38. The interior of the perforated center tube provides a central fuel chamber 52. The fuel outlet 16 is in communication with the central fuel chamber 52 through the tubular coupling 20.

Positioned partially within the filter housing 22, in the lower end thereof, is a support plate generally indicated by numeral 54 that is seen in detail in Figures 2, 3 and 4. The support

plate 54 has an integral radially extending flange portion 56 providing an upper surface 58 and a lower surface 60. The support plate 54 further has an integral downwardly extending tubular portion 62 having an external circumferential surface with threads 64.

The support plate flange lower surface 60 engages the interior of the inwardly folded lower end 34 of the housing 22 so that thereby the support plate 54 is secured to the housing 22.

Threadably attached to the support plate tubular portion 62 is a contaminant container 66 (see Figure 1) having an integral radially extended flange portion 68 with an upper flange surface 70. The upper interior of the contaminant container 66 is provided with internal threads 72 that threadably engage the threads 64 of the support plate tubular portion 62. A circumferential groove 74 is formed in the contaminant container upper surface 70, the groove

74 being adaptable to receive an O-ring (not shown) so that the upper end of the contaminant container 66 is sealably secured to the inwardly folded lower end 34 of the filter housing 22. In this manner, the interior 76 of the contaminant container 66 is in closed communication with the interior of the housing 22 and specifically, in communication with the peripheral fuel chamber 48 within the housing 22. Integrally formed on the upper surface

58 of the support plate flange portion 56 (see Figures 2, 3 and 4) is an upstanding spiraled ledge 78. As shown in Figures 2 and 3, the spiral ledge 78 begins on the upper surface 58 adjacent the external periphery of the support plate flange

portion 56 and spirals to terminate adjacent a tubular opening 80 in the support plate 54. The upstanding spiral ledge 78 provides a spiral fuel passageway 82 that communicates the interior of the contaminant container 66 with the peripheral fuel chamber 48 of the housing 22.

When fuel enters inlet 14 and flows into the peripheral fuel chamber 48 to surround the fuel element 36, any water or other immiscible contaminant that is heavier than the fuel, including, dirt, sand, rust, etc., will settle by gravity to the interior lower end of the housing and flow by way of the spiral passageway 82 into the contaminant container 66. The fuel filter lower end plate 44 that rests on the upstanding ledge 78 forms the upper boundary of the passageway 82.

The provision of a spiral passageway 82 communicating the interior of the filter housing with the interior of the contaminant container 66 has the important advantage that it isolates the interior of the contaminant container 66 from turbulence of fuel flow within the filter housing 22. That is, the long spiral passageway 82 provides free flow of contaminant from the housing 22 into the contaminant container 66 but shields the contaminant container 66 from any turbulence of fuel within the housing 22 that would otherwise tend to recombine the fuel with contaminant that has been separated and that has passed into the contaminant container 66.

The claims and the specification describe the invention presented and the terms that are employed in the claims draw their meaning from the use of such terms in the specification.

The same terms employed in the prior art may be broader in meaning than specifically employed herein. Whenever there is a question between the broader definition of such terms used in the prior art and the more specific use of the terms herein, the more specific meaning is meant.

While the invention has been described with a certain degree of particularity, it is manifest that many changes may be made in the details of construction and the arrangement of components without departing from the spirit and scope of this disclosure. It is understood that the invention is not limited to the embodiments set forth herein for purposes of exemplification, but is to be limited only by the scope of the attached claim or claims, including the full range of equivalency to which each element thereof is entitled.