Abstract:
A filter relief valve assembly for a simple, easy to assemble use with filter structures of the common oil filter throw away type which will function to permit oil bypass of the filter element whenever the fluid pressure exceeds a predetermined value. The assembly unit is complete unto itself, but when assembled with the other filter components support and center one end of the filter element and also center and align an associated check valve in cooperation with the filter end closure.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to filter relief valves and especially to a unit assembly type device which may be used with various types of filters of conventional throw-away type. 
     2. Description of the Prior Art 
     A common problem with known type relief valve assemblies for use with filter elements and especially of the throw-away type is that the relief valve assembly are unduly complicated, require close assembly tolerances, and are not easily installed on assembly lines and the like with rapidity and without precise installation equipment. 
     Another problem with known type devices is that they use a combination relief valve and check valve structure which increase the complexity of the assembly, and also further increase manufacturing accuracies and tolerances as well as complexity of the structure. 
     Another problem with known type combination relief valve and check valve assemblies is that the relief valve structure per se may not readily be used with other type structures because of the integral check valve structure. 
     Known prior art patents which are pertinent to the disclosed invention are the patents to Paul, U.S. Pat. Nos. 3,262,567; Humbert, Jr., 3,332,554; and Humbert, Jr., 3,529,722. The Paul patent employs pressure responsive relief and regulating valves which are in the form of annular spring discs. These spring discs are made of material of high yield strength and high hardness. And are not of flexible, resilient rubber-like material. Both of the patents to Humbert, Jr. relate to combination check valve and bypass valve structure and are not of the relatively simple, minimum element arrangement of the invention disclosed herein. 
     A Hathaway et al U.S. Pat. No. 3,083,832 has a combination by-pass and check valve structure employing an annular sealing member together with a metal spring element for maintaining the aforesaid sealing member in proper position against valve seat structure. Again, the structure is dual purpose with the additional complexities associated therewith. Another U.S. Pat. No. 3,166,498 to Otto, Jr., employs check valve structure and is not arranged to function as a relief valve. In fact, an entirely separate relief vavle structure is required with this device. The Thorton U.S. Pat. No. 3,321,089 again combines bypass and check valve structure into a combination device. This structure is also far more complicated with the requirement of precision assembly than that of the invention disclsoed herein. The Thorton et al U.S. Pat. No. 3,567,022 is a single operating relief valve structure, but has a number of different parts including a coil spring which greatly increases the expense and assembly problems with the use of such a device. 
     The patent to Bumb, U.S. Pat. No. 3,984,318, granted on Oct. 5, 1976, shows a sub-assembly for use with an oil filter wherein a Belleville spring by-pass valve is in combination with a rubber antidrainback valve. Again, this structure is far more complicated and involved than that of the applicants&#39; invention. 
     None of the known prior art patents have the new and unique features of the invention set forth herewithin. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a relief valve assembly which may be used in many different applications, especially for use with a fluid filter of the throw-away type. 
     Another object of the present invention is to provide a simple, easy to assemble relief valve unit which may be quickly and easily mounted within the center tubular portion of a filter element to function as a support for this end of the filter element as well as a relief valve to permit fluid upon reaching a predetermined pressure to bypass the filter element entirely. 
     A further object of the present invention is to provide a filter element relief valve sub-assembly which may be used for both supporting and aligning the filter element as well as aligning an associated check valve structure in conjunction with the end closure member for the overall filter shell. 
     A still further object is to provide a relief valve assembly having a specially configured gasket member in association with an angular support flange wherein the amount of fluid pressure required to open the valve may be changed by varying the shape of the gasket member, the angle of the support flange, and the material of the gasket member. 
     The device of this invention includes a relief valve assembly having an annular support member with an inwardly radial flange thereon and an outwardly extending radial flange thereon, together with another double tubular support member with the smaller inner tubular member having a valve seat formed at one end with the opposite end being connected by a radial flange to the outer tubular member, and the outer tubular member having a plurality of fluid passageways or apertures provided therein. The outer tubular member is also provided at the opposite end with a rolled extending flange for cooperation with the inwardly extending radial flange of the first annular support member to securely mount a resilient gasket member therebetween. The resilient gasket member is washer-like in shape and in the unassembled form is in the shape of a cone. When assembled between the two annular support structures the outer periphery of the gasket member is securely pressed between the support flanges and fastened in the assembly. Meanwhile, the inner peripheral portion of the gasket member and the adjacent area thereto, because of the unique configuration of the gasket member is resistently biased against the valve seat of the inner tubular support member. Depending upon the material from which the gasket member is formed, the amount of fluid pressure required to deflect the gasket member and enable fluid to flow through or by same may be accurately predetermined. 
     In one application of this relief valve assembly, it is used in combination with an oil filter cartridge of the conventional throw-away type, wherein the sub-assembly is centered within the central tubular area of the filter element and firmly engaged therewith in a fluid-tight manner. The outward radial flange of the first annular support member is used to engage with and support the paper end disc as associated with the filter element. 
     An inwardly recessed or deformed area on the outer tubular support member of the relief valve assembly provides a space for reception of associated structure of check valve mechanism. Such as a pressure spring ring for use with a check valve gasket, with said pressure spring ring being centrally aligned, held, and spaced by this recessed shoulder of the assembly. During overall filter manufacture, when the end enclosure portion of the filter is attached to the outer consister shell, the check valve gasket and spring assembly are simultaneously centered and aligned because of the use of this relief valve assembly unit. 
     Another embodiment of this invention includes the extension of the radially extending outer flange of the first support member outwardly a sufficient distance to function and replace the paper end disc as normally associated with the filter element. An upwardly extending or axially extending edge flange provides a full metal end cap for the filter element, and greatly improves the overall supporting and aligning function of the relief valve assembly. 
     These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevational view, partly in cross section, of an oil filter having the relief valve assembly of this invention combined therewith. 
     FIG. 2 is a side elevational view, in cross section across the center line of the relief valve assembly per se of this invention. 
     FIG. 3 is an exploded perspective view of the component parts of the relief valve assembly of this invention. 
     FIG. 4, is a perspective view of a modification of the filter element contacting portion of the relief valve assembly of this invention. 
     FIG. 5 is a side elevational view, partly in cross section, of the modification of FIG. 4 of this invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Looking at FIG. 1 of the drawings, reference numeral 10 indicates in general the throw-away type oil filter cartridge with which the relief valve assembly of this invention may be used. A cylindrical canister 12 having a closed end 13 with filter element aligning end supporting structure 15 together with end cap 17 supports one end of the filter element 14. The filter element 14 has a central tubular portion 16 provided with fluid flow apertures 18. The open end of the cylindrical canister 12 is provided with an enclosure disc 20 having fluid inlet holes 21 provided circumferentially around a central fluid outlet aperture 22. This aperture 22 is normally internally threaded for screwing the overall filter cartridge upon a complementary projecting threaded stud on an engine. Another separate plate 24 having corresponding apertures therein to those of disc 20 is normally assembled to the canister 12 by rolling the outer edges of the combined materials together as indicated at 25. Also, an engine seating gasket 26 is normally provided with this plate. Also, an alignment and retention recess 27 is provided in disc 20 for reception of the raised portion 28 on the closure plate 24. 
     The fluid flow lines indicated by A show the normal flow of the fluid into the inlet holes 21 and through the inside of the canister housing through the filter element 14, into the center of tube 16, and out through opening 22, back to the engine or other device with which the filter is being used. Generally, the flow lines indicated by B indicate the bypass function of this relief valve sub-assembly whenever the filter element 14 becomes sufficiently clogged to prevent pass of fluid therethrough, and/or if the fluid itself should be of such thickness and consistency as not to readily flow through the filter element. That is the relief valve will allow fluid to bypass the filter and return through opening 22 back to the engine in the same manner as already described. 
     Looking at FIGS. 2 and 3 of the drawings, the relief valve assembly will now be described in detail. A first tubular support member 30 is provided having a radially extending flange member 34 at one end thereof, and a reduced axially extending portion 31 extending from the other end thereof. The reduced annular portion 31 is in turn provided with an inwardly radially extending flange 32. While the outwardly extending flange 34 is at right angles or perpendicular to the center axis of tubular support member 30, the inwardly extending flange 32 is at an angle relative to the center line. This angle indicated by θ in FIG. 2, is normally between 50° to 85° and preferably is between the range of 65° to 70°. 
     The second tubular support portion of the assembly is indicated by reference numeral 45 and is in the form of a tubular member 40 having a rolled end for forming a valve seat 42. The opening 44 permits maximum fluid flow through this tubular member 40. The other end of tubular member 40 is contiguous with an outwardly extending radial flange portion 46. A recessed shoulder portion is formed by connecting portions 47 and 48 and connect to the outer tubular member 50. This outer tubular portion 50 is provided with a plurality of apertures 51 for the passage of fluid therethrough. While one or two of such fluid passageways would function, the inventors have discovered that a plurality of same, preferably at least eight, function in an advantageous manner, and also without decreasing the necessary strength of the support member 40-50. The outer tubular member 50 also is provided with a rolled end 52 similar to the rolled end 42 of tubular member 40. However, the rolled end 42 which functions as a gasket valve seat, has the roll in the inward direction to form the opening 44, while the rolled end 52 on tubular member 50 is rolled outwardly to form a somewhat bendable outer edge 54. This is quite important with this device in that this outer edge 54 securely and basically permanently engages within tubular member 30 at the point where deformation and reduction of member 30 indicated by reference numeral 33 in FIG. 2 occurs. It is the complementary engagement of portions 33 and 54 which securely holds the support members 30 and 40-50 together. 
     Only one additional element is needed for completion of the relief valve assembly. This is the element 60 which is the gasket member for the structure. This gasket member 60 is of necessity formed of a resilient flexible material which is normally impervious to oil, gas, and other fluids of deleterious nature. The inner opening 64 is of slightly smaller diameter than the diameter of opening 44. Thus, when the outer periphery 62 of the gasket member 60 is securely retained between the radial flange member 32 and the rolled portion 52, as best seen in FIG. 2, the gasket will be securely held in proper operating position. 
     Another feature is in the shape of gasket 60 prior to assembly. Normally as contemplated in this invention, the gasket member 60 will have a cone shape with an angle X of approximately 30° from the face plane of the member. That is, normally the angle of the side portions on the inner and outer sides of the gasket member, shown as C and D in the figures, will be at an angle comparable to the angle θ of the inwardly directed radial flange 32. Thus, with this conical shape and angular relationship, when the outer periphery 62 is mounted, as best seen in FIG. 2, the inner portion of the side D near the opening 64 must of necessity be forced against the valve seat 42. The amount of this resilient biasing is predetermined by proper selection of the gasket material. Also, the degree of cone angle may be varied in order to vary this resilient biasing function. That is, with higher density, less flexible and resilient material, the bias force will be increased, and thereby the fluid pressure required to open the valve gasket also will be substantially increased. Furthermore, by increasing the cone angle in the direction towards making a sharper cone, likewise will increase the degree of pressure bias, and thus increase the predetermined pressure at which the valve member will open. Similarly, a change in angle θ of the flange 32 will effect a change in pressure value. 
     Another important feature of this invention is in the shoulder portions 47 and 48, as best seen in FIG. 2, which connect the radial flange 46 and the outer tubular member 50. This recessed shoulder, labeled E, provides support for associated check valve structure, if desired, when the unit is mounted as in FIG. 1 with a filter cartridge structure. As thus seen in FIG. 1, a metal spring member 70 is centered and aligned by means of the recessed shoulder E and in turn engages with a flexible gasket member 72 which in turn engages with the base portion 74 on the disc 20. Thus, the check valve gasket 72 will prevent unwanted return of fluid to the engine or the like through the inlet openings 21. While the outer peripheral portion of gasket 72 engages with the projection raised rib 76 of member 20, the inner annular opening of the gasket 72 is mounted on the projection 78 defining opening 22 of disc 20. 
     Another embodiment of this invention may be seen in FIGS. 4 and 5 wherein the outwardly radial flange 34 is substantially extended 34&#39; for elimination of the conventional paper end disc 19 as seen in FIG. 1. The radial flange 34&#39; is of sufficient size to completely cover the associated end portion of the filter element 14 and also provided with an axially aligned flange 84 to complete encase and support the associated end of filter element 14. Much in the manner of the full metal and cap 17 for the other end of the filter element as seen in FIG. 1. By using this modification, the paper end disc 19 may be completely eliminated, thus reducing the number of necessary elements in the disposable oil filter cartridge, and thus also decreasing the assembly and overall cost. 
     Normally the outer circumference of the gasket member 60 will be just slightly smaller than the internal circumference of the tubular member reduced portion 31, so that during assembly, the cone shaped gasket may be easily inserted and mounted within member 30. Then the support element 40-50 will be pressure fitted or forced into the inner circumference of tubular portion 30 to securely lock and retail the gasket member in place. With the proper amount of valve bias resulting due to; the angle of the gasket member 60, the radial flange 32, and the material from which the gasket member 60 is formed. If a desired predetermined fluid pressure is to be changed to either a lower or higher value, the production run may easily call for a substitute of gasket member 60 of different material, or different cone angle and shape, and/or the flange member 32 angle φ may be changed. Normally, the distance between the flange 46 and the rolled valve seat 42 is the same as that between flange 46 and the rolled shoulder engaging portion 52. However, by changing the relative distances and dimensions thereof, another way of changing the predetermined fluid pressure is provided. That is, by decreasing the distance F the predetermined pressure valve may be reduced. 
     The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be restored to, falling within the scope of the invention.