Patent Application
20080060991
There is shown in the attached drawing a presently preferred embodiment of the present invention wherein like numerals refer to like elements and wherein:
There is shown in
The combination valve 26, which is retained between the lower end of the filter element 14 and the top of the end plate 18, is unitary in construction, for example, by molding, and includes a first anti-drainback portion 28 for controlling flow through the first inlet opening or openings 19 and a second bypass portion 32 for controlling flow through the second inlet opening or openings 21. The first portion 28 is more resilient than the second portion 32 and will open under a lesser pressure, whereas the second portion 32 is stiffer and requires a higher pressure to open same. In a presently preferred embodiment of the invention, the first portion 28 of the combination valve 26 will open the first inlet openings 19 at a minimum opening pressure, for example, on the order of 1 psi and the second portion 32 will open the second inlet opening 21 at a predetermined higher pressure, for example on the order of 8-10 psi. Provided centrally in the end plate 18 is a central threaded outlet opening 23. The outlet opening 23 is disposed about the longitudinal axis of the filter assembly 10 and is within the circle of second openings 21. In a presently preferred embodiment of the invention, there are eight first inlet openings 19 and six second inlet openings 21 in the end plate 18. Other opening configurations than round are feasible and the number of openings can be varied as will be apparent to persons skilled in the art, depending upon the application for the filter assembly 10.
The combination valve 26 of the present invention includes a first portion 28 that is annular and has a bend intermediate the radial extent of the first portion 28. The part of the first portion 28 that engages the second portion 32 extends generally horizontally and the free end is inclined outwardly and downwardly from the horizontal portion. The second portion 32 includes an annular inwardly inclined part that is adapted to cooperate with the second inlet openings 21 and an upwardly extending part 38 that cooperates with the horizontal part of the first portion 28 to form a shoulder 40 that receives the lower inner end of the core 16 of the filter means 15. The part 38 is annular and engages the interior of the lower end of the core 16 of the filter means when assembled. The combination valve 26 is formed unitarily, e.g., by molding, from a suitable material, e.g., nitrile or silicone rubber compound.
The end plate 18 is suitably secured to the lid 20, for example, by welding. Projections 44 extend from the bottom of the end plate 18 to facilitate the connection of the end plate 18 to the lid 20. The recess 42 in the lid 20 is adapted to receive and retain the gasket 22 (
The resilient gasket 22 will be retained in the recess or groove 42 during handling of the filter assembly 10 and the projections (not shown) define cooperative engaging means for holding the gasket in place. Persons skilled in the art will understand that the gasket 22 can be similarly retained in place in the recess 42 if the projections on the lid 20 were eliminated and projections were provided on the outside or inside surfaces of the gasket 22 for engaging with the walls of the recess 42. Such arrangement would function in an equivalent manner.
The end plate 18, as seen in
The filter means 15 may comprise a conventional pleated filter media 14 composed, for example, of cellulose with some polyester. The core 16, which may be molded from an appropriate material, for example, a glass filled plastic, such as, Nylon, is perforated so as to permit fluid flow there through in use. Essentially, the core 16 comprises a cage formed by vertically disposed members 16a suitably secured to horizontally disposed members 16b. The filter media 14 is formed from a sheet of pleated material joined along the facing ends by a suitable adhesive to form an annular sleeve on the cage 16.
At the top and bottom are disposed end caps 50 and 52, respectively. The end caps 50 and 52 may be fabricated from a suitable composite material, for example a cellulose/polyester composite. Preferably, the end caps 50 and 52 are bonded to the filter media 14, for example, by ultrasonic welding, to form a seal between the ends of the filter media and the end caps to prevent fluid flow between these elements in use. Essentially the materials for the filter media 14, the core 16, and the end caps 50 and 52 are compatible for ultrasonic welding to fuse the parts to one another. This process eliminates the need for adhesive and the oven curing that was done in the past. The top end cap 50 is a generally annular plate that has an opening in the center thereof for receiving and engaging a spring member 54 to help bias or urge the filter means 15 in the housing 12 toward the end plate 18. The bottom end cap 52 is a generally annular plate that has an opening in the center thereof and projections (not shown) extending from the periphery thereof. As disclosed in the prior co-pending application, there are three projections on the end cap 52. The projections are adapted to abut the interior of the housing 12 to facilitate assembly of the filter means into the housing 12 and to properly position the lower portion of the filter means 15 in the housing 12.
A resilient seal 56 is disposed between the top end cap 50, the core 16 and the spring 54 to preclude fluid flow between these elements. The seal 56 may be composed of felt or felt-like material. The opening in the center of the annular filter media 14 will be closed to fluid flow by the center portion of the spring 54 when the filter means 15 is assembled in the housing 12. The resiliency of the seal 56 will apply a downward biasing force to the filter means 15. The lower part of the core 16 will engage the outer surface of the upwardly extending part 38 of the combination valve 26 to seal between the lower end of the filter and the combination valve 26.
In accord with the present invention the anti-drainback portion 28 of the combination valve 26 is provided with a plurality of cross cut slits 60-64 constructed and arranged to open to allow fluid flow through the fluid filter assembly in a reverse direction during initial engine fill and to close and provide a seal when the anti-drainback valve operates normally in operation. In the illustrated embodiment, there are five (5) slits arranged in a non-symmetrical pattern. The cross cut slit 60 includes a first generally radial slit 60a and a slit 60b transverse thereto. The slits 60a and 60b extend through the anti-drainback portion 28 of the combination valve 26. Slits 61, 62, 63 and 64 are similarly formed in the anti-drainback portion 28 of the combination valve 26. Though the slits 60-64 are intended to operate only during initial oil fill they perform an important function that is desired by users of the filter assembly 10. Thereafter the filter assembly functions normally, with the slits 60-64 being effectively closed to fluid flow.
The slits 60-64 are asymmetrically formed in the anti-drainback portion 28 of the combination valve 26. It is desired that at least one cross cut slit be aligned with an opening 19 in the end plate 18 when the filter assembly 10 is assembled, with the fewest number of cross cuts in the combination valve 26. In a presently preferred embodiment there are five cross cut slits 60-64. Radial slits 60a and 61a, 61a and 62a, 62a and 63a, and 63a and 64a are each offset from one another by 54 degrees. Radial slits 64a and 60a are offset by 144 degrees. With the five cross cuts in the anti-drainback valve portion 28 of the combination valve 26 and the eight equally spaced openings 19 in the end plate 18, the equivalent of one cross cut slit is over an opening 19 at all times. This is accomplished by one cross cut slit being over an opening 19, or by one-half of a cross cut slit being over one opening and one-half of a cross cut slit being over another opening 19, or three quarters of one cross cut slit being over one opening 19 and one quarter of another cross cut slit being over another opening 19, etc. The radial slits and the transverse slits of each cross-cut slit 60-64 are each about 0.200 inch long and extend through the anti-drainback portion 28 of the combination valve 26. The slits 60-64 are constructed and arranged so as to provide a functional leak free part in normal use of the combination valve 26. The slits 60-64 open only during initial engine fill.
The assembly of the filter assembly 10 will now be described. The filter means 15 is assembled with the annular filter media 14 on the core 16 and the end caps 50 and 52 secured in place. The end plate 18 and the lid 20 are secured together, for example, by welding, and the gasket 22 is positioned and retained in the recess 42 of the lid. The filter means 15 is positioned in the housing 12 abutting the spring 54, which is engaged in the upper end of the filter means 15 help to properly center the top of the filter means 15 in the housing 12. The seal 56 will preclude fluid flow between the filter means 15 and the housing 12. The combination valve 26 is positioned in the core 16 with the part 38 engaging the inner surface of the core 16 to help seal fluid flow between the combination valve 26 and the core 16 of the filter means. The end plate 18 is inserted to close the open end of the housing 12 and the outer rim of the lid 20 is rolled with the open end of the housing 12 to form a seal 80. Positioning of the end plate 18 in the housing 12 partially compresses the seal 56, whereby, when the parts are assembled an additional spring force is applied to the filter means 15 urging the filter means toward the end plate 18. The combined forces of spring 54 and seal 56 will help to retain the combination valve 26 between the filter means 15 and the end plate 18 and to seal flow from between the filter means and the end plate 18. The core 16 will firmly engage the part 38 of the combination valve 26 and will also engage and bear upon the generally horizontal region of the first portion 28 of the combination valve 26.
In operation, the filter assembly 10 is spun onto a stud on the engine block which engages the threads in the central opening 36 in the end plate 18 and is secured in place. The gasket 22 will engage the engine block and preclude fluid flow from between the engine block and the filter assembly 10. Original equipment engine plants desire to flow oil through the filter to prime the oil pump prior to starting the engine. This is not possible with conventional filters having an anti-drainback valve in place because the anti-drainback valve prevents reverse flow through the filter. Therefore, many first fit filters do not contain an anti-drainback valve. This can potentially cause dry starts in the field, engine knocks and customer complaints. With the inventive combination valve 26 in place, fluid flow through the outlet opening 23 and through the filter media 14 can exit via the cross cut slits 60-64 in the anti-drainback valve 26. The slits 60-64 are positioned so as to always have the equivalent of one slit mated with an opening or openings 19 in the threaded plate or end plate 18. The slits 60-64 open and allow flow in the reverse direction during initial engine fill, but close and provide an adequate seal when the combination valve is functioning normally. When the engine is started, fluid, usually oil, will enter the filter assembly through the openings 19. Slight pressure will move the anti-drainback portion or check valve portion 28 of the combination valve 26 away from the openings 19 and oil will flow through openings 19, the filter media 14 and be discharged through the central outlet opening 23 for return to the engine. When the engine is turned off, the first anti-drainback portion or check valve portion 28 of the combination valve 26 will close the openings 19 and prevent return of oil in the filter assembly 10 to the engine. As the filter media 14 clogs during normal operation, pressure will build within the housing 12 of the filter assembly 10 and upon attainment of a predetermined pressure, on the order of 8-10 psi for one present application, the second portion or bypass portion 32 of the combination valve 26 will open and permit oil to flow through the openings 21 and outlet opening 23 back to the engine, thereby bypassing the filter media 14. Stated somewhat differently, during periods of time when high differential pressure exists across the filter media, due to cold thick oil or high contaminant loading of the filter media, the oil will go through the inner circle of openings 21 and open the second portion 32 of the combination valve 26 to permit oil to bypass the filter media 14 and exit the filter assembly 10 through the outlet opening 23 for return to the engine.
The present invention materially reduces the number of parts needed for a line of filters. Presently standard automotive filter assemblies are grouped into multiple filter diameters. A main line of filter assemblies heretofore consisted of multiple core diameters and multiple core heights. With the present invention, filter sizes can be consolidated and the complexity of internal components can be reduced significantly, for example to one core diameter and two core heights. Fabrication and assembly of the filter assemblies are simplified and can easily be automated. The filter media, core and end caps are non-metallic and can be easily recycled. The unique end cap design and orientation of the openings therein is a facilitating factor in both construction and operation of the filter assembly. The construction of the combination anti-drainback valve and bypass valve and the cooperation of the combination anti-drainback valve and bypass valve with the end plate contribute to easier assembly and enhanced performance. The respective circles of openings in the end plate are fairly close to one another. The combination valve is constructed so that it can be retained in place against the end plate by the core 16 of the filter means by contact between the two circles of openings. This arrangement seals fluid flow through one circle of openings from the fluid flow through the other circle of openings. Tolerances need not be tight to obtain the sealing results desired. The slits in the anti-drainback portion of the combination valve 26 cooperate with the inlet openings 19 in the end plate 18 to permit flow in the reverse direction during initial engine fill and thereby permit use of a filter assembly that includes a combination valve that with an anti-drainback portion.
While it will be understood by persons skilled in the art that the spring 54 could be eliminated and that a concave portion could be provided in the closed end of the housing to help reduce the overall height of the filter assembly, such modification of the filter assembly would not affect the operation of the combination anti-drainback and bypass valve of the present invention.
While a presently preferred embodiment of the present invention has been shown and described, it will be apparent to persons skilled in the art that the invention may be otherwise embodied within the scope of the following claims.
