Fuel filter housing

A fuel filter assembly (10) comprising an electrically non-conductive housing (12) with a layer (28) of electrically conductive material extending from the distal end (22) of an inlet connector (20) to the distal end (26) of an outlet connector (24) for conducting electrical charges completely through the housing (12) from distal end (22) to distal end (26). The housing (12) is fabricated by first forming an inlet half of the housing (12) with an opening and forming an outlet half of the housing (12) with an opening. The conductive layer (28) is disposed separately over the interior of the respective housing halves. Thereafter, the respective openings of the housing halves are fused together with the housing material fused together and the conductive layers (28) of the respective halves in electrical contact.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates a fuel filter used in the fuel line to an internal combustion engine and, more specifically, to such a fuel filter having anti-electrostatic electrical properties.

2. Description of the Prior Art

High electrostatic charges can occur in fuel line systems for supplying fuel to internal combustion engines. The discharge of such electrostatic charges can cause damage to the system. In order to alleviate this problem, both the fuel line per se and the filter housing have been made electrically conductive.

In the U.S. Pat. No. 5,798,048 to Ries the filter housing comprises an electrically nonconductive layer sandwiched between electrically conductive layers in order to provide an electrical path from the inside to the outside of the housing.

In the U.S. Pat. No. 6,171,492 to Hedgepath et al the filter housing is made of an electrically conductive material or composition for conducting electrical charges and includes a space between inner and outer walls to reduce weight and material.

The U.S. Pat. Nos. 5,076,920 and 5,164,084 to Danowski et al also teach a filter housing molded of a mixture of a plastic and an electrically conductive additive.

There remains a constant need to improve the fuel filter in terms of combinations of materials and structure with electrical conductivity.

SUMMARY OF THE INVENTION AND ADVANTAGES

The subject invention provides an improved fuel filter assembly wherein the housing is formed of an electrically non-conductive material and is characterized by a layer of electrically conductive material extending from the distal end of the inlet to the distal end of the outlet for conducting electrical charges completely through the housing from distal end to distal end.

The inlet and outlet of the fuel filter assembly of the subject invention may be connected to fuel lines which are electrically conductive to provide an electrical discharge path throughout the fuel line system.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the Figures, wherein like numerals indicate like or corresponding parts throughout the several views, a first embodiment of the fuel filter assembly of the subject invention is generally shown at10inFIGS. 1 and 2.

The assembly10includes a housing, generally indicated at12, having a peripheral wall14with an interior and an exterior and extending between an inlet end16and an outlet end18. The housing12includes an inlet connector20integral with and extending from the inlet end16of the housing12to an inlet distal end22and an outlet connector24integral with and extending from the outlet end18of the housing12to a distal end26. The housing12comprises or consists of an electrically non-conductive material. The material of the housing12is a plastic or organic polymeric material. Examples of such materials include nylon, a nylon alloy, a polyethylene, thermoplastic elastomers, etc.

The assembly10is characterized by a layer28of electrically conductive material extending from the distal end22of the inlet connector20to the distal end26of the outlet connector24for conducting electrical charges completely through the housing12from distal end22to distal end26. The conductive layer28covers the entire interior of the housing12between the distal ends22,26thereof whereby any fuel flowing through the housing12is prevented from contacting the non-conductive material of the housings12. The conductive material may comprise a variety of Fuel Low Permeation materials including a variety of fluoropolymers, including FEP-perfluorinated ethylene propropylene, PFA-perfluoralkoxy fluorocarbon, ETFE, and other suitable materials such as VFEP, THV sold by Dyneon. Corp., and liquid crystylline material, LCP.

The non-conductive material of the housing12extends along each of the inlet20and outlet24connectors to respective ends27and29that are spaced axially inwardly from the distal ends22and26whereby the conductive material is exposed axially along the ends of each of the connectors20and24. Annular ribs31are dispersed in each of the exposed lengths of conductive material28for connection to fuel lines, or the like. In addition, the exposed lengths of the conductive material28is radially thicker between the ends27and29of the nonconductive material in the connectors20and24and the distal ends22and26of the connectors20and24.

The housing12includes a filter support, generally indicated at30, extending inwardly from the outlet end18to a rim32and defining an enlarged passage34aligned with the outlet connector24. A shoulder36is formed for abutting a filter cartridge, which is generally indicated at38. The cartridge38includes a disk-like inlet end piece40which directs the flow of fluid radially outwardly and an outlet end piece42which supports the cartridge38on the support30as it abuts the shoulder36. A well-known filter material44extends between the end pieces40and42. The fuel is forced to flow outwardly to the circumference of the filter material44and then radially inwardly through the filter material44to the center of the annular filter material44. Thereafter, the fuel flows into the enlarged passage34and into the outlet connector24to a hose or tube.

The conductive coating28extends around the filter support30, the rim32, into the enlarged passage34of the filter support30and into the outlet connector24to the distal end26of the outlet connector24. In this manner, no fuel is allowed to contact the material of the housing12.

The embodiment ofFIG. 4includes a second layer50sandwiched between the housing12and the conductive layer28. The second layer50comprises a non-conductive material. The second layer50defines an extension52of the rim32.

In the embodiment ofFIG. 4, the rim32is disposed closer to the outlet connector24than the shoulder36whereby the second layer50covered by the conductive layer28forms the extension52, i.e., the support portion of the housing does not extend fully into the filter38.

The non-conductive material of the housing and the second layer50both terminate at ends or shoulders27and29spaced inwardly from the distal ends22,26of the connectors20,24to expose the conductive material28.

As will be appreciated, the filter assembly10may include an integrally molded or fused bracket, as generally indicated at60inFIG. 1for mounting to vehicle structure.

The invention also includes a method of fabricating the fuel filter assembly10by forming the housing12of an electrically non-conductive material having a peripheral wall14with an interior and an exterior and extending between inlet16and outlet18ends and an inlet connector20integral with and extending from the inlet end16of the housing12to a distal end22and an outlet connector24integral with and extending from the outlet end18of the housing12to a distal end26, and wherein the method is characterized by disposing a layer28of electrically conductive material extending from the distal end22of the inlet connector20to the distal end26of the outlet connector24for conducting electrical charges from completely through the housing12form distal end22to distal end26.

As alluded to above, the method is further defined as forming the conductive layer28over the entire interior of the housing12between the distal ends22,26thereof whereby any fuel flowing through the housing12is prevented from contacting the non-conductive material.

The method may continue by sandwiching a second layer50of non-conductive material between the housing12and the conductive layer28. In the method the housing12is formed thicker than either of the conductive layer28and the second layer50.

As illustrated in the Figures, the housing is fabricated from two halves, an inlet half and an outlet half joined together at an annular fused joint60. The method may be further defined as forming an inlet half of the housing12with an opening and forming an outlet half of the housing12with an opening, disposing the conductive layer28over the interior of the respective housing halves, and fusing the respective openings of the housing halves together with the housing material fused together and the conductive layers of the respective halves in electrical contact. The halves may be fused together by spin welding, pressing, or various well-known steps.

Obviously, many modifications and variations of the present invention are possible in light of the above teachings. The invention may be practiced otherwise than as specifically described within the scope of the appended claims, wherein that which is prior art is antecedent to the novelty set forth in the “characterized by” clause. The novelty is meant to be particularly and distinctly recited in the “characterized by” clause whereas the antecedent recitations merely set forth the old and well-known combination in which the invention resides. These antecedent recitations should be interpreted to cover any combination in which the incentive novelty exercises its utility. In addition, the reference numerals in the claims are merely for convenience and are not to be read in any way as limiting.