Fluid Filter Drain Assembly

This invention relates to fluid filters, and more particularly, to the drain assembly for draining contaminants from the collection bowl of such fluid filter.

One of the problems concerned with fluid filter assemblies, particularly for diesel engines and the like, is the removal of contaminants from the filter assembly which typically are collected in the bottom of a collection bowl and which may include not only water removed from the fuel, but solid particulate matter as well. These contaminants can foul the drain valves which are provided in the collection bowl for periodic maintenance purposes, which fouling often affects proper closure of the drain valve or results in the contaminants being retained in the filter assembly for possible reentrance in the fluid being filtered. Another problem associated with devices of this type is the difficulty in removing the contamination from the collection bowl in that if a simple drain valve is employed, a partial vacuum is created in the fluid filter resulting in a difficult, if not impossible, drainage process.

Prior art drain assemblies are known which are self-venting, but these often have been complex and costly to construct. Certain of these devices are constructed in such a manner that portions of the drain assembly might be completely unscrewed and the parts separated with possible loss of a component part. Further, on others there is a risk that the drain assembly might accidentally be left in its open position, with consequent loss of fuel. In many of these devices contamination near the drain or vent valve openings within the collection chamber, may tend to collect and prevent proper closing of the particular drain or vent valve and it would be advantageous to have a valve structure which would tend to clear the upper drain and vent passages during the draining cycle.

One form of prior art drain assembly is shown in U.S. Pat. No. 4,314,689. In this device the drain valve includes a plug disposed in the internal passage which cooperates with a transverse bore in the drain valve in such a manner as to prevent contamination of the actuation device. This form of valve provides an efficient type of drain valve which is not so subject to clogging conditions.

Another form of drain valve assembly is shown in U.S. Pat. No. 4,502,956. In this assembly the drain valve is designed to cooperate with first and second collection zones within the collection portion of the filter, which zones are walled off from one another and commonly relieved by the drain valve mechanism. In this arrangement one contaminant outlet is upstream of all of the filter media in the filter assembly and the second contaminant outlet is downstream of at least a portion of the filter media.

Still another form of drain valve assembly is shown in U.S. patent application Ser. No. 784,300 now U.S. Pat. No. 4,724,074 assigned to the assignee of the instant invention. This drain assembly has a self-venting feature wherein a first opening in the valve assembly is uncovered to allow an initial discharge of the fluid in the collection bowl or the like, with a second opening thereafter uncovered to allow air to be introduced into the collection bowl to assist in the drainage process. This form of drain valve assembly comprises a threaded plug having plural passages therein and which are in fluid communication with a pair of outlets in the bottom wall of the collection bowl, one of the outlets being at a higher elevation therein than the other.

The apparatus of the instant invention is an improvement over such prior art devices in providing a simplified drain valve assembly comprising the combination of individual drain and vent valves which are disposed in the bottom wall of the collection bowl of a fluid filter for diesel engine fuel and the like, and which valves coact in their motion to provide a sequential initial opening of the drain valve and a later opening of the vent valve.

The drain valve and vent valve are disposed closely adjacent one another in the bottom wall of the contaminant collection bowl with the drain valve mounted in such a way that it can be rotated relative to the collection bowl and/or the cartridge in the fuel filter assembly and to provide a vertical motion for opening and closing the drain valve. The drain valve includes an annular flange thereon which during its upward motion engages the actuating member of the vent valve to open the latter only after the drain valve has been initially opened. In one embodiment of the invention the drain valve is a push type valve which is spring biased to a closed position and has the valve seat formed in the bottom wall of the collection bowl. In both embodiments of the invention the vent valve is also a spring loaded valve, biased to the closed position and mounted in such a disposition that the seat thereof is at a higher elevation than the seat of the drain valve. Preferably, in both embodiments of the invention the vent valve is a tire core type valve commonly known in the trade as a Schrader type valve which is commonly employed for introducing air into vehicle tires and the like.

In a preferred embodiment of the invention the drain valve comprises a valve stem threaded into the bottom wall of the collection bowl for achieving vertical movement and opening and closing of the drain valve seat therein by rotation of the valve stem. This valve also includes an annular flange which engages the vent valve to open the latter after the drain valve has been opened. In both embodiments of the invention a hose connector is included as a portion of the drain valve assembly to provide means for directing fluid by way of flexible hose or tubing to a discharge location, which valve assemblies allow relative rotation between the hose connector and the collection bowl and/or the cartridge of the valve for replacement of the latter, while maintaining the hose untwisted. In the preferred embodiment of the invention a swivel connection is employed between the hose connector and the stem of the drain valve to allow such relative rotation.

Referring now to the drawings, FIG. 1 is a sectional view of a fluid filter assembly including one embodiment of drain valve assembly located in the bottom wall of the collection bowl thereof;

FIG. 2 is an elevational view of the collection bowl portion and drain valve assembly of FIG. 1;

FIG. 3 is a bottom view of the collection bowl and drain valve assembly of FIG. 2;

FIG. 4 is an enlarged elevational view partly in section of the drain valve assembly of FIG. 1 shown in the closed condition;

FIG. 5 is an enlarged elevational view partly in section of the drain valve assembly of FIG. 1 shown in the open condition;

FIG. 6 is an enlarged elevational view partly in section of the preferred embodiment of drain valve assembly shown in the closed condition;

FIG. 7 is an enlarge elevational view partly in section of the preferred embodiment of drain valve assembly shown in the open condition;

FIG. 8 is an enlarged sectional view of the vent valve forming a part of the drain valve assemblies; and

FIG. 9 is a plan view of the hose connector portion of the drain valve assembly of the preferred embodiment of the invention, removed from the remainder of the assembly.

Referring now to the drawings, FIG. 1 describes a typical fluid filter assembly 10 comprising filter head 11, filter cartridge 12, collection bowl 14 and drain assembly 15. Filter head 11 is conventionally mounted to the engine or other appropriate location in an engine compartment and comprises an inlet port 16 and outlet port 17 and includes a central threaded connector tube 18 in fluid communication with outlet port 17. A heater element 19 may be included in filter head 11 for heating diesel fuel and the like prior to filtration of same, but the details of the heater are not essential to an understanding of the instant invention.

Filter cartridge 12 is a cylindrical casing containing annular filter medium 20 separating the cartridge into peripheral fuel zone 21 and central fuel chamber 22 and may also include perforated support tube 24 in the central fuel chamber 22. Adapter ring 25 is included in the lower portion of the filter cartridge 12 being externally threaded on a lower tubular portion thereof for receipt of collection bowl 14. Cartridge 12 includes a rigid upper wall 26 which is threadedly received on connector tube 18 and which allows ready replacement of cartridge 12 for service and maintenance purposes. An annular seal 27 is included at the top of cartridge 12 for sealing engagement with filter head 11 and to establish closed fluid communication paths between the fuel chambers 21, 22 in cartridge 12 and the inlet and outlet ports 16, 17.

Collection bowl 14 is a cup-shaped member having bottom wall 28 and peripheral side wall 29, the latter internally threaded and adapted to be received on the threaded portion of adapter ring 25 for securement and separation from cartridge 12. A typical o-ring seal 30 provides a fluid tight connection between collection bowl 14 and cartridge 12.

It will be understood that fuel to be filtered enters filter head 11 at inlet port 16 and is directed by way of heater element 19 to outer peripheral chamber 21, to flow through filter medium 20, central peripheral chamber 22 and by way of connector tube 18 to outlet port 17. Water and other contaminants which tend to collect on the outer periphery of filter medium 20 will drop to the lower portion of peripheral fuel chamber 21 and pass through radial channels in adapter ring 25 to be deposited in the bottom of collection bowl 14. Collection bowl 14 further includes in the bottom wall 28 thereof water sensor element 31 which can detect the presence of water at a certain level in collection bowl 14 to provide a signal that such contaminants should be removed therefrom. Such water sensor essentially comprises conductive rod 32 which passes through an insulated sleeve of the water sensor and thus through the bottom wall of collection bowl 14 to be contacted by the water therein.

The circular configuration of collection bowl 14 may be seen more clearly in the elevation and bottom views of FIGS. 2 and 3 respectively which also include views of the water sensor 31 and drain valve assembly 15. Collection bowl 14 preferably includes a plurality of ridges 35 distributed about its periphery to assist in gripping and twisting of the latter relative to cartridge 12 for removal and replacement purposes.

One embodiment of drain valve is shown more clearly in the enlarged views of FIG. 4 and 5 as comprising drain valve 40 and vent valve 41 mounted closely adjacent one another in the bottom wall 28 of collection bowl 14. Drain valve 40 comprises cylindrical valve stem 42 slidably and rotatably mounted in bore 43 formed in the bottom wall 28 and a downwardly protruding hub portion 44 for further support. The inner end of valve stem 42 is reduced and receives o-ring seal 45 which is further held in place by means of washer 46 and snap ring 47 so that o-ring seal 45 is supported for movement with valve stem 42. The inner end of bore 43 at the junction of the inner surface of bottom wall 28 forms annular valve seat 49 through which valve stem 42 extends and against which o-ring seal 45 engages for opening and closing of drain valve 40.

At the lower portion of valve stem 42 and integral therewith is annular flange 50 which is a generally circular member which extends transversely sufficiently far to underlie vent valve 41 and which includes shoulder 51 as the upper surface portion thereof and a transversely extending hose connector 52. Annular flange 50 serves to couple drain valve 40 and vent valve 41 for common actuation.

A cross bore 54 is included in the upper portion of valve step 42 just below the location of valve seal 45 and which communicates by way of right angle bore 55 in stem 42 and flange 50 with hose connector 52, the latter having a plurality of barbs 56 thereon and comprising a push on connector or coupling for hose or tubing which serves to direct contaminants away from drain assembly 15 to a remote location. A coil spring is disposed over hub 44 and acts between bottom wall 28 and shoulder 51 of annular flange 50 to urge drain valve 40 to the normally closed condition depicted in FIG. 4.

Vent valve 41 is seen in more detail in the cross sectional view of FIG. 8 as comprising a tubular, typically brass body plug 60 having a central bore 61 therein terminating at one end in annular valve seat 62 and closed at the other end by an externally threaded plug member 64, the latter being securely clenched to body member 60 and adapted for sliding receipt of valve pin 65. Body plug 60 includes sleeve seal 66 at a midportion of its periphery to provide sealing engagement with the bore in which the vent valve 41 is located. At its upper end, vent valve 41 includes plunger cup 68 which is also clenched as at 69 to valve pin 65 for movement therewith, plunger cup 68 receiving annular plunger washer 70, the latter further retained in place by ferrule 71 secured to valve pin 65, all of which move with valve pin 65 as an assembly. A conical compression spring 72 is positioned between an internal shoulder in body plug 60 and a further ferrule 74 clenched to valve pin 65 to urge valve pin 65 in a downward direction and thus to urge plunger washer 70 into engagement with valve seat 62 to provide a normally closed condition for vent valve 41.

Referring more particularly to FIG. 5, it may be seen that vent valve 41 is positioned in boss 75 in bottom wall 28 of collection bowl 14, which boss 75 has a partly threaded interior bore 76 to place valve seat 62 of vent valve 41 at a higher elevation in collection bowl 14 than valve seat 49 of drain valve 40. As drain valve 40 is actuated by manual elevation of annular flange 50, o-ring seal 45 will be elevated from valve seat 49 to allow initial flow of liquid and contaminants in collection bowl 14 through cross bore 54, right angle bore 55 and outwardly of hose connector 52. During this initial priming phase a partial vacuum will be drawn in collection bowl 14, cartridge 12 and a part of filter head 11 preventing or interfering with drainage of fluid through outlet bore 55. As drain valve 40 is further elevated, shoulder 51 of annular flange 50 will engage valve pin 65 of vent valve 41 to cause opening of the latter. As depicted in FIG. 5 in the fully open position annular flange 50 has been fully elevated into contact with boss 44 fully compressing spring 58 and elevating valve pin 65 against the bias of compression spring 72 to raise plunger cup 68 and plunger washer 70 contained therein to a position spaced from valve seat 62. In this condition a path for entry of air into collection bowl 14 is provided by way of the bore in lower plug member 64, the bore 61 of body plug 60 and valve seat 62. Replacement of air within collection bowl 14 will allow complete drainage of the fluid and contaminants contained therein through the outlet bore 55 of drain valve 40.

It will be noted that the transverse extent of annular flange 50 of drain valve 40 is sufficient so that a portion of shoulder 51 underlies valve pin 65 no matter what the angular orientation of drain valve 40 with respect to collection bowl 14. It is also apparent that drain valve 40 may be held in a stationary position as when connected to drainage hose or the like so that collection bowl 14 and/or cartridge 12 may be unthreaded from one another or from filter head 11 for replacement or maintenance purposes without removing the hose. In all angular orientations the cooperation between drain valve 40 and vent valve 41 is maintained. It will be further apparent that when upward pressure is released from drain valve 40, the latter will be urged to its normally closed position by return spring 58 and that vent valve 41 will similarly be returned to its normally closed condition by internal conical spring 72 until the respective positions depicted in FIG. 4 are attained. It will still further be apparent that annular flange 50 of drain valve 40 provides a protective shield over valve pin 65 to prevent inadvertent actuation of the latter other than when drain valve 40 is intentionally being actuated. Still further, it will be clear that both drain valve 40 and vent valve 41 have a self cleaning characteristic for contaminants which may be located about the respective valve seats 49, 62. Thus, as valve stem 42 is raised and lowered relative to bottom wall 28, a scraping action will occur at valve seat 49 tending to clear contaminants thereat with the cross bore 54 normally being protected from contamination by being disposed in bore 43 below the normally closed valve seat 49. Similarly, in vent valve 41 when plunger washer 70 is elevated above vent valve seat 62 and air flows through central bore 61, the inrush of air will tend to clear contaminants from valve seat 62 so that closing of vent valve 41 will not be impeded.

While the embodiment of the invention depicted in FIGS. 4 and 5 provides a simplified structure and easily actuatable drain valve assembly, it is desired in certain instances to have a more secure configuration of drain valve structure which can be forceably retained in its full open and full closed conditions and which is not subject to inadvertent opening thereof. For this reason the preferred assembly of drain valve assembly 80 depicted in FIGS. 6 and 7 is provided. Drain valve assembly 80 comprises an identical vent valve 81 and a similar drain valve 82, the latter comprising an externally threaded cylindrical body member 84 received in threaded bore 85 in the bottom wall 28 of collection bowl 14. Drain valve body member 84 includes threaded cap 88 at its upper end which houses and retains annular seal 89 for movement with body member 84 into engagement with annular valve seat 90 formed in the inner surface of bottom wall 28, again at an elevation substantially below that of valve seat 62 of vent valve 81. Body member 84 includes cross bore 91 at the upper portion thereof below valve seal 89 which is in communication with central bore 92 terminating at boss 93 at the lower end thereof. Body member 84 further includes integral annular flange 95 at the lower end thereof similar to flange 50 of drain valve 40, being of generally circular configuration and having an upper circular surface forming shoulder 96 for engagement with valve pin 65 of vent valve 81.

It will be apparent then as annular flange 95 of drain valve 80 is rotated from the position depicted in FIG. 6, valve seal 89 will be initially lifted from valve seat 90 to allow fluid communication to cross bore 91 and outlet bore 92 and an initial priming of the chamber formed by collection bowl 14. Upon continued upward movement, shoulder 96 of annular flange 95 will engage valve pin 65 to move vent valve seal 70 to a position separated from vent valve seat 62 allowing the entrance of air through valve 81 in a manner similar to that described with respect to the first embodiment of the invention. The fully open position of drain valve assembly 80 is shown in FIG. 7. Similarly, when annular flange 95 is threaded in the opposite direction to return drain valve 80 to its lowermost position as depicted in FIG. 6, valve seal 89 may be urged into tight and secure engagement with valve seat 90 to provide a secure closure of drain valve 80. During this downward movement, vent valve 81 will be returned to its normally closed condition by internal compression spring 72 in a manner similar to that previously described.

Drain valve 80 further includes hose connector 96, again including a laterally extending barb-type coupling, and a swivel connection between hose connector 96 and annular flange 95. As seen more clearly in FIG. 9, hose connector 96 comprises circular body member 100 having a central upstanding boss 101 with a central bore 102 therein in communication with coupling bore 104 passing through the barbed coupling portion of hose connector 96. Hose connector 96 further includes a plurality of circumferentially spaced upstanding flanges 105 surrounding boss 101, each flange 105 having a laterally extending barb 106 at the upper tip thereof adapted to be received in an annular groove 108 formed in the bottom of annular flange 95 in a slidable, snap fit, swivel connection therein. Hose connector 96 is preferably an injection molded plastic member allowing a certain degree of resilience to flanges 105 to allow them to be pressed into groove 108 and to be retained therein. As hose connector 96 is placed on the lower portion of body member 84, boss 93 will be received in bore 102 of boss 101 in a press-fit engagement to provide a fluid tight interconnection therebetween, even though hose connector 96 may be rotated relative to adapter flange 95. Thus, it may be seen that hose connector 96 may be retained in a stable axial position, connected to hose or tubing, while adapter flange 95 is threaded relative to bottom wall 28 or while collection bowl 14 is rotated relative to cartridge 12 as well as when cartridge 12 is rotated relative to fluid head 11 when being removed for replacement and maintenance purposes.

It may also be seen that a self cleansing action of the drain valve 80 of the preferred embodiment of the invention is achieved when valve stem 84 is elevated and that cross bore 91 is protected within bore 85 beneath valve seal 89 and valve seat 90 in a manner similar to that previously described with respect to the first embodiment of drain valve 40.