US2728460A - Fuel filter - Google Patents

Description

Dec. 27, 1955 D. E. COLLIS ET AL 2, 6

FUEL FILTER Filed Feb. 18, 1953 [III/III,

0 4 A. 6011/: R404 A flue/Name.

INVENTOR.

wamw FUEL FILTER Dan E. Collis and Paul A. Auringer, Benton Harbor, Mich.

Application February 18, 1953, Serial No. 337,522

9 Claims. (Cl. 219-170) This invention relates to improvements in fuel filters, and more particularly, to a gasoline filter adapted to be interposed in a line between a gasoline tank and an internal combustion engine. The filter is designed particularly for heavy duty use, as for farm tractors, spray rigs and industrial equipment of the character in which a gasoline tank is located at an elevation above the engine so that the fuel filter is located at a level below the tank.

The primary object of the invention is to provide a fuel filter adapted for connection to a fuel tank at the bottom thereof and constructed to include a valve element which is spring pressed toward closed position and which is held open only when the filter element is in its assembled sealed condition.

A further object of the invention is to provide a novel, simple, efficient, inexpensive, and readily cleanable fuel filter.

A further object is to provide a fuel filter having a spring pressed valve and a fusible positioning or stop member associated with the valve and normally serving as a stop to limit closing movement by the spring when the device is assembled, said fusible member being adapted to melt at a low temperature to respond quickly to any fire condition for the purpose of closing the valve and stopping flow of fuel through the filter member.

A further object is to provide a device of this character having a valve stem of configured cross-section extending through a passage and manipulatable when the filter chamber is opened for the purpose of discharging dirt within the passage.

A further object is to provide a device of this character having a valve formed of a material immune to reaction with the fuel and normally shape-retaining but capable of flexing or distortion under spring pressure to seat around a small particle of dirt bearing on the valve seat. e

A further object is to provide a device of this character with a cup body formed of aluminum or other material having rapid heat transfer properties and with a readily fusible valve-positioning member in direct con tact with said cup body.

Other objects and advantages of the device will be apparent from the following specification.

in the drawing:

Fig. 1 is a vertical sectional view of the device taken on line 1-1 of Fig. 2;

Fig. 2 is a vertical sectional view of the device taken on line 2-2 of Fig. 1;

Fig. 3 is a sectional view taken on line 33 of Fig. l; and

Fig. 4 is an enlarged axial sectional detail view.

Referring to the drawing which illustrates the preferred embodiment of the invention, the numeral designates a fuel tank having an opening in its bottom in which is fixedly secured a fitting 12 having a screw-threaded axial vertical bore 14 extending therethrough. The fitting 12 has flanges 16 which are welded or otherwise secured 2,728,460 Patented Dec. 27, 1955 to the tank around the opening therein in a manner to effect a seal at the joint between the tank and the fitting, and a central tubular portion 18 preferably depends from the fitting whereby the screw-threaded bore is of substantial length.

The fuel filter has a housing which is formed of two parts, one part 2i) thereof being fixed, and the other part 22 being cup-shaped and removably connected with the part 20. The part 20 is formed of metal and has a large diameter disklike portion 24 having a central or axial passage 26 extending therethrough. A reduced externally screw-threaded tubular extension portion 28 projects upwardly from the body 24, and the passage 26 extends therethrough. The tubular portion 28 is screw-threaded in the tapped bore 14 of the fitting 12, and its end portion 30 projects above the level of the upper face of the fitting 12, as best seen in Fig. l. The upper edge 32 of the tubular extension is of frusto conical shape to define a valve seat.

The bottom surface of the body 24 is interrupted by an annular concentric groove 34 which communicates with a transverse internally screw-threaded passage 36 constituting an outlet passage, said passage 36 being spaced from the bottom surface of the body 24. A depending neck portion 38 at the center of the body 24 outlines the inner edge of the groove 34 and in turn has a reduced diameter terminal portion 4i). A depending marginal flange 42 is located at the outer margin of the member 24. The surfaces of the body at opposite sides of the groove 34 are preferably substantially flush to provide an abutment against which the inner and outer marginal portions of a wire screen 44 of disk shape and having a center opening bears. The opening of the screen or other filter member 44 is of a size to fit snugly around the reduced neck portion 49, and the overall size and shape of the screen 44 is such as to fit within the cavity outlined by the marginal flange 42. A gasket ring 46 presses against the outer margin of the screen 44 and is interposed between the same and the lip of the cup-shaped body part 22.

The cup-shaped body part 22 is preferably formed of metal and its side walls 50 preferably taper upwardly toward its free edge, and its bottom wall 52 is preferably substantially flat. The diameter of the cup 22 at its free edge is such that it fits with a snug fit within the flange 42 to bear in continuous face engagement and in sealing relation to the gasket 46. The cup 22 is preferably formed of metal, and aluminum or other metal having a property of rapid heat conduction is preferred.

The body 24 has diametrically opposed sockets 54 intermediate its axial dimension to receive rotatably the inturned end portions 56 projecting from the sides 58 of a U-shaped bail having an end or cross part 60. The bail is so constructed that it is free to swing about the parts 56 as a center and has clearance with the body part 22. A boss 62 is carried fixedly by the bail portion at its center and a screw-threaded stud 64 projects from the boss 62 in the plane of the bail arms 58 and substantially centered therebetween.

A nut or presser member 66 has a screw-threaded bore and is mounted upon the stud 64. The nut preferably includes a flange 68 which is enlarged and peripherally knurled or roughened to afford a firm hand grip to facilitate turning of the nut. The nut 66 is adapted to bear against the bottom wall 52 of the cup 22 to press or urge the same toward the body part 20 and applies sufficient pressure to effect a seal between the body parts 20 and 22 at the gasket 46. It will be apparent that manipulation of the nut to release pressure upon the cup 22 conditions the parts for ready separation; that is, after the nut has been withdrawn from pressure applying contact with the cup 22, the bail is free to swing to a position clear of the cup, it being understood, of course, that the cup will be held manually as thebail is swung until such time as-it can be withdrawn from operative relation with the member 20 without interference from the bail. Conversely, to assemble the housing parts it is necessary only to apply the cup 22 into position as illustrated, and then'to swing the bail to a centered position whereupon the nut 66'is tightened to apply the sealing pressure to the member 22.

A valve is carried by the device and includes a valve head 70 of a size and shape to fit upon the valve seat 32 in sealing engagement therewith, as illustrated in Fig. 2. The valve head may be formed of any material chemically inert to the fuel and preferably will be formed of a material of sufficient rigidity to maintain its shape and to permit exertion of sealing pressure thereto but at'the same time will be sufiiciently soft so that it may cold flow around particles of sand or the like which may bear between it and the valve seat so as to insure an effective sealing sealing engagement with the valve seat. The valve head is mounted upon a valve stem 72 which is elongated and is longer than the inlet passage 26. The valve stem has elongated flutes 74 extending longitudinally thereof for the major portion of its length, the same preferably being of a length substantially equal to the length of the inlet passage 26 and having a snug but rotative and longitudinally slidable fit within that passage. The portion 76 of the valve stem below or outwardly of the fiuted portion 7 4 thereof is externally screw-threaded. A tubular member 78 having internal screw threads is mounted upon the free lower end of the stem portion 76, and its position upon'the stern may be adjusted as desired by reason of its screw-threaded connection with the stem.

The tubular member 78 projects below or beyond the end of the portion 76 of the stem and preferably has a plurality of slots 80 at its lower free end cooperating to define longitudinal finger portions 82 which releasably grip a removable stem portion or insert 84. This insert is generally circular and its diameter is such that it has a snug fit in the socket defined by the finger portions 82 of the collet or chuck tube 73. A circumferential flange 86 is formed at the longitudinal center of the member 84 and is adapted to bear against the ends of the fingers 82 to limit the extent to which the member 84 may be inserted lengthwise into the chuck 78. The assembled valve stem, as illustrated in Fig. 1, is preferably of a length greater than the spacing between the inner surface of the wall 52 of the cup 22 and the valve seat 32 so that the: normal operative position of the parts, as illustrated in Fig. l, entails the positioning of the valve 70 spaced from the valve seat 32 and in open position when the end portion 84 of the valve stem bears against the cup wall 52.

An annular member 96, such as a disk or plate, encircles the threaded valve stem portion 76 and is adapted to bear against the inner end of the chuck or collet-78. A coilspring 92 encircles the'valve stem with clearance and one end thereof bears against the annular member 90, and the opposite end thereof presses against the inner marginal portion of the filter element or screen 44.' The spring is of such character that it will cause the valve to move to seated position at all times that it is free to do so without interference from the elongated valve stem.

In the use of the device it will be apparent that when the device is assembled in the normal operative condition as illustrated in Fig. 1, liquid, such as gasoline or other fuel, is free to pass from the tank 16 through the inlet passage 26, as between the flutes 7'4, and thus enters the cup 22. In order for the fuel to pass to the outlet passage 36, it must enter the groove 34 which is spanned by the filter member or screen 44, and thus any dirt carried by the fuel is retained within the cup 22. The cup 22 thus collects any dirt which passes through the line, and such dirt tends to precipitate to the bottom of the cup, thus providing effective flow of fuel for long periods of time without clogging of the filter, even under adverse operating conditions in which substantial quantities of dirt enter the tank.

Such conditions, for example, are encountered frequently with agricultural tractors or other-units operating in dirt laden atmospheres.

The device is readily cleaned to remove the accumulated dirt by simply disassembling it and removing the cup 22, which can be accommodated by manipulation of the nut 66, as explained above. On such occasions, as the nut 66 is released to permit downward movement of the cup 22, the valve 70 will be moved toward seated position to seal the outlet passage by means of the operation of the spring 92. Thus, as soon as the cup 22 is free for removal, the valve will be seated and all danger of drainage of the tank 10 is avoided automatically. The cup 22 can then be removed and accumulated dirt withdrawn therefrom and, if necessary, the screen 44 can be removed for cleaning purposes and for access to the groove 34 and the passage 36. This enables a complete cleaning operation to be performed by the simple means of removing the cup 22 and the operation can be performed while the tank 10 contains liquid without danger of loss or much more liquid than the cubic capacity of the housing chamber. It will be apparent by the same token that to recondition the system all that is required is to reapply the cup 22 and to mount it in sealed position, this operation, accomplished by threading the nut 66 against the cup 22 to effect a sealed engagement thereof at the gasket 46, will automatically serve to open the valve 70 as the assembly operation is performed.

One of the important characteristics of this device is that the occurrence of clogging action is localized by reducing to a minimum the need for changes in direction during the flow of liquid in the'device from its inlet to its outlet. The single straight pass from inlet to the interior of the cup, which pass is defined by the straight passage 26, is important in this particular. Consequently, when dirt or foreign material from the tank enters the passage, there is minimum impedance to its travel into the cup 22. Furthermore, by reason of the fluted character of the valve stem, the removal of such dirt as may accumulate within the passage is rendered simple after removal of the cup 22 in the manner described above. In other words, it will be apparent that the stem of the valve may be manipulated, both rotatively and by axial shifting, when the cup 22 has been removed, and such manipulation will serve to clear the passage 26 of accumulations of dirt therein. These characteristics provide the dual advantage of minimizing the locations at which dirt may lodge in the device to clog it and of simplifying and expediting release of dirt from the device when it is clogged.

The provision of the device'eliminates the necessity of providing a separate drain plug in the fuel tank of a vehicle in instances where the device is mounted at'the' bottom of that fuel tank as illustrated in Figs. 1 and 2. Thus, although the valve 70 is seated automatically by the spring 92 upon removal of the cup 22, as explained above, the device may be manipulated to drain the fuel from the tank if desired. This can be accomplished either by manually pressing the valve stem toward releasingposition against the action of the coil spring or it can be accomplished by means of a prop or other means for mechanically holding the valve stem open. In particular, it is possible to manipulate the nut 66 upon the threaded stud 64 to advance the same into contact with the end of the valve stem after the cup 22 has been released and removed from the device. It will be apparent that the threaded adjustment of the nut upon the threaded stud 64 accommodates opening of the valve to any extent desired, thereby to regulate the rate at which fluid is discharged from the tank 10.

One of the most important advantages of the'device is its automatic closing operation in the event of life. Tractors and other devices in which fuel tanks are positioned above an engine are particularly subject to a fire hazard in the event any leakage should occur in the fuel line or in the filter unit or in the connections of the fuel line or filter unit with each other or with the fuel tank. The engine block becomes very hot and, if the fuel leaks and falls upon the engine block, it ignites because of the heat of the block and the resulting fire may cause an explosion with the danger of great damage to life and property as well as great damage to the tractor or vehicle itself. In the present construction such danger is minimized because the valve 70 is closed automatically to stop the discharge of fuel if an excessive heat condition in the area of the fuel filter ocurs. This is made possible by the formation of the terminal portion 84 of the valve stem from a fusible material having a low melting point. I prefer to use a material whose melting point is in the neighborhood of 170 F. in order to provide adequate sensitivity and yet to avoid danger of fuel being cut off when the heat of the engine rises in hot weather as the vehicle is working under a heavy load.

If a fire or other cause results in the exposure of the device to a high temperature, that temperature is rapidly transferred to the fusible stem portion 84 by reason of the formation of the cup 22 from a metal, such as aluminum, having a high heat transfer characteristic. The fusible valve stem portion 84 is in direct contact with the bottom 52 of the cup 22 so that the heat transfer from the cup to the part 84 occurs by direct conduction. The low melting point of the part 84 permits it to fuse or melt shortly after the fire or other excessive heat condition commences and before the fire gains headway and becomes unmanageable. The melting of the member 84 is illustrated at 84' in Fig. 2. This melting of the member 84 permits the spring 92 to urge the valve toward valveclosing position. This operation starts before the full melting action occurs, and, in this connection, it will be apparent that as soon as the fusible material commences to soften, its strength will reduce and movement of the valve toward closing position may commence. The automatic closing of the valve in this manner will limit the amount of fuel which can continue to leak to sustain the fire, and the danger of consumption of the entire fuel content of the tank by either fire or explosion is rendered negligible.

One characteristic of the device which is convenient for use and for reconditioning of the device after destruction of the fusible part 84 is the ease with which the part 84 is mounted on the valve stem. Assuming that a fire occurs which destroys the member 84, it will melt and substantially cover the bottom of the cup 22 and will flow from and be released from the collet or socket 82. In reconditioning the device for use, the melted material may be removed from the cup, for which purpose the cup is completely removed from the body of the filter as explained above. Thereupon the melted metal may be pried from the cup or additional heat may be supplied to re-melt it and permit it to flow and thus be discharged from the cup. A new member 84 is then inserted into the chuck 78, the cup is replaced and reconnected, and the device is again ready for use. In order that there may be accurate positioning of the part 84 and control of the overall length of the valve stem so that the stem length will be the same upon replacement of the fusible member as it was previously, the parts 84 will preferably be formed of uniform construction. The circumferential rib 86 provides a stop engageable with the ends of the fingers 82 for positioning purposes. The opposite ends of the member 84, that is, the ends at opposite sides of the rib 86, will preferably be of equal length so that the device will project a predetermined distance from the end of the collet 78 regardless of the manner in which the part 84 is inserted therein. This arrangement is well illustrated in Fig. 4.

While the preferred embodiment of the invention has been illustrated and described herein, it will be understood that changes in the construction may be made within the scope of the appended claims without departing from the spirit of the invention.

We claim:

1. A fuel filter comprising a two-part housing defining a chamber and having a substantially horizontal partupper end of said inlet passage and including a depend-' ing stem portion extending through said inlet passage with uniform clearance and normally engaging the lower housing part to hold said valve open, and a spring for urging said valve downwardly toward sealing position, said valve stem mounting a stop and said spring constituting a coil encircling said stem between and bearing at its ends against said stop and said filter element.

2. A fuel filter comprising a two-part housing defining a chamber and having a substantially horizontal parting plane, one of said parts being adapted to be fixed to a support, the upper of said parts having spaced inlet and outlet passages therein communicating with said chamber, said inlet passage being open ended and substantially vertical and unrestricted throughout the length, a filter element mounted in said housing in engagement with the bottom of said upper part spaced from said inlet passage to intercept fuel flowing from said inlet passage to said outlet passage, means releasably connecting said housing parts, a valve adapted to seal the upper end of said inlet passage and including a depending stem portion extending through said inlet passage with uniform clearance and normally engaging the lower housing part to hold said valve open, and a spring for urging said valve downwardly toward sealing position, said stern fitting in said inlet passage rotatably and having longitudinal flutes in its passage-received portion.

3. A fuel filter comprising a two-part housing defining a chamber and having a substantially horizontal parting plane, one of said parts being adapted to be fixed to a support, the upper of said parts having spaced inlet and outlet passages therein communicating with said chamber, said inlet passage being open ended and substantially vertical and unrestricted throughout its length. a filter element mounted in said housing in engagement with the bottom of said upper part spaced from said inlet passage to intercept fuel flowing from said inlet passage to said outlet passage, means releasably connecting said housing parts, a valve adapted to seal the upper end of said inlet passage and including a depending stern portion extending through said inlet passage with uniform clearance and normally engaging the lower housing part to hold said valve open, and a spring for urging said valve downwardly toward sealing position, said spring engaging said filter element to press the inner portion thereof against said upper housing part.

4. A fuel filter comprising a two part housing defining a chamber and having a substantially horizontal parting plane, one of said parts being adapted to be fixed to a support, the upper of said parts having spaced inlet and outlet passages therein communicating with said chamber, said inlet passages being open ended and substantially vertical and unrestricted throughout its length, a filter element mounted in said housing in engagement with the bottom of said upper part spaced from said inlet passage to intercept fuel flowing from said inlet passage to said outlet passage, means releasably connecting said housing parts, a valve adapted to seal the upper end of said inlet passage and including a depending stem portion extending through said inlet passage with uniform clearance and normally engaging the lower housing part to hold said valve open, and a springEfor urging saidvalve downwardly toward sealing position, the interior surface of said upper housing'part having an endless recess encircling and spaced from said inlet passage and interrupting a substantially flat bottom surface portion, said filter element having a central opening registering with said'inlet passage and bearing on said flat bottom surface portions, said spring pressing the inner marginal portion of said screen against the bottom surface of said upper housing part between said inlet and recess.

5. A fuel filter comprising an imperforate cup, a top portion spanning the open end of said cup to define a liquid confining chamber, means detachably connecting said top and cup, said top having a straight substantially vertical inlet passage and an outlet including a recess in the inner surface of said top spaced from said inlet passage, a filter screen clamped marginally between said top and cup and having an opening registering with said inlet passage, a valve including a stern slidably guided in said inlet passage with substantially uniform clearance and a head above said top and adapted to seat thereagainst around said inlet passage, said valve being of a length to hold said head open when its stern bears against said cup in the sealed connection relation of said top and cup, and spring means urging said stem in end engagement with said cup and pressing the portion of said screen around said opening into continuous engagement with the inner surface of said top between said'inlet passage and said recess.

6-; A=fuel filter'as defined in clairnS, wherein said cup" is formed 'of metal to render-it substantially non-frangible when exposed to internal' expansiveforces and has its side walls tapering-upwardly and outwardly.

7. A fuel filter-as defined inclaim 5, wherein apart of said valve stem normally contacting said cup is formed of a metal fusible at-a temperature lower than the temperature at which fuel-in the chamber will ignite.

8. A fuel filter as defined in claim 5, wherein said valve stem includes a socket-within said cavity and afusible member-detachably mounted in'said socketand bearing against said cup.

9. A fuel filter as defined in claim-5,- wherein saidconnecting means includes a bail anchored to said top and extending-vertically around s'aid-cup'and'a' vertically adjustable pressure" member substantially aligned with said valve stem.

References Cited in the file of this patent UNITED STATES'PATENT'S 688,86} Kemp Dec. 17, 1901 781,018 Palmer Ian'. 31, 1905 1,062,236 Hitchcock May 20; 1913 1,720,380 S'chulze July 9, 1929" 1,746,274 Otis Feb. 11; 1930 1,782,702 Wheeler Nov. 25; 1930 2,289,539 Guno Jn1y14, 1942 2,301,014 Burklin' Nov. 3, 1942

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