The present invention relates generally to engine or transmission oil filters. More particularly, the present invention relates to tray inserts for supporting filter media in engine or transmission oil filters, preferably metal or composite engine or transmission oil filters.
Engine and transmission oil filters can include a housing encompassing a filter medium. The housing typically has a top half (or upper cover) and a lower half (or lower cover) and can be all metal, all plastic, or can be composite in construction (metal and plastic). In filters having clean fluid both above and below the filter medium (for example, in bag configuration), the filter medium is preferably kept off the bottom of the lower half of the filter so that fluid can flow to the filter outlet unobstructed by the filter medium.
In the case of composite filters with a metal lower tray, flow ribs stamped into the metal lower tray are used to keep the filter bag medium from touching the bottom of the lower tray and thereby blocking fluid flow. This design can have drawbacks. First, the ribs themselves block fluid flow space and can create bottleneck regions in the fluid flow path. Second, in order to provide structural support to alleviate the effects of suction on the oil filter housing, pinch points are built into the oil filters, where a depression in the upper tray presses against a rib in the lower tray. These pinch points compress the filter bag medium, obstructing fluid flow.
All-plastic oil filters, on the other hand, have the drawback that the top half of the housing and bottom half of the housing cannot be crimped together without the use of an additional binding ring. Therefore, expensive welding processes are used to seal the tray halves together. In addition, certain welding processes such as vibration welding cause contamination of the filters. Filter media fibers can dislodge due to the friction of the vibration welding process and contaminate the filter. As well, all-plastic oil filters require a larger wall thickness to achieve comparable strength and stiffness to a composite filter and consequently many users demand composite oil filters.
Engine or transmission filters also typically include inlet tubes. These tubes can be made from metal or they can be made from plastic. Metal inlet tubes are typically formed as a separate component because metal cannot be drawn from the lower tray to the depth or shape that is often needed for the inlet tubes. Utilizing a separate component adds cost to the filter. Further, because separate metal tubes are attached by crimping, the cross-sectional geometry of the metal tubes is limited, and angled or shaped tubes are difficult to implement. Specifically, metal inlet tubes are limited to having a round or oval cross-sectional geometry because it is difficult to crimp other metal shapes. Use of angled or shaped inlets can introduce error in the manufacturing process because an operator must insure that the inlet tube is properly oriented rotationally prior to crimping. While all-plastic tubes can be integrally formed when used with all-plastic filters thereby alleviating the problem of limited manufacturable cross-sectional geometry and angle, as mentioned above, all-plastic filters can have the problem of contamination and/or expense.
Accordingly, it is desirable to provide an oil filter method and apparatus that alleviates the fluid flow problems caused by use of lower metal trays having stamped flow ribs. It is also desirable to provide an oil filter method that can utilize the thin walls provided by metal covers. It is also desirable to provide an oil filter method and apparatus that alleviates the fluid flow problems caused by pinch points closing the media (as in a bag filter). It is also desirable to provide an oil filter method and apparatus that includes an inlet tube which can be both cost-efficient and has desirable design flexibility.
The foregoing needs are met, to a great extent, by the present invention, wherein in one aspect an apparatus is provided that in some embodiments provides a tray insert for an engine or transmission filter for supporting the filter media off the bottom of the lower cover.
In accordance with one embodiment a filter for engines or transmissions is provided having a filter housing encompassing a plastic tray insert for supporting filter media off the bottom of the filter housing. The tray insert is configured to rest on the filter housing, which includes an upper half and a lower half. In some embodiments, the tray insert rests on the bottom of the lower half of the filter housing. In some embodiments, the tray insert rests on a lip portion of the lower half of the filter housing and is suspended above the bottom half of the filter housing. In some embodiments, the suspended tray insert also includes legs extending downward toward the bottom of the lower half of the filter housing. In some embodiments, the plastic tray insert can include integral pass-through pinch points. In some embodiments, the plastic tray insert can include an integral plastic inlet opening which may be configured with an anti-drainback device.
In accordance with another embodiment, a filter for engines or transmissions is provided having a filter housing, including an upper half and a lower half and encompassing a metal tray insert for supporting a filter bag off the bottom of the filter housing. In some embodiments, the tray insert is configured to rest on a lip portion of the lower half of the filter housing and is suspended above the bottom half of the filter housing. In some embodiments, the suspended tray insert also includes legs extending downward toward the bottom of the lower half of the filter housing.
In accordance with another embodiment of the present invention, a metal or composite engine or transmission filter includes filtering means, means for housing said filtering means wherein the means for housing includes a lower tray, means for suspending the filtering means within said means for housing wherein the means for suspending is not integral with the lower tray.
In accordance with yet another embodiment of the present invention, a method for alleviating fluid flow problems associated with filters having ribs stamped into the lower housing tray is provided. The method includes providing a tray insert for use with a metal or composite oil filter. In some embodiments, the method also includes positioning the tray insert in the lower housing tray of an oil filter, positioning the filter media on the tray insert, and positioning an upper housing tray above the filter media and lower housing tray.
There has thus been outlined, ratherbroadly, certain embodiments of the invention in order that the detailed description thereof herein may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional embodiments of the invention that will be described below and which will form the subject matter of the claims appended hereto.
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of embodiments in addition to those described and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting.
As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
The invention will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout. A metal or composite engine or transmission filter can comprise a two-part housing having a lower cover and an upper cover encompassing a filter media (these embodiments show the media in a bag configuration). The housing covers are either both metal, or in the case of a composite filter, on cover can be plastic, while the other cover is made from metal. According to the prior art, to support the filter media above the bottom of the lower cover, yet still permitting fluid flow along the bottom portion of the lower cover, the lower metal cover is stamped with a series of spaced-apart ribs protruding into the interior of the filter housing. The ribs support the filter media above the bottom of the lower tray, and the space between the ribs provides regions for fluid flow.
The present invention provides a tray insert which can take the place of stamped metal ribs, and thus can be used with metal covers which do not have stamped metal ribs. The tray insert is adapted to rest within the filter housing such that the filter media is supported above the bottom of the lower filter cover by the tray insert.
According to some embodiments of the invention, the tray insert is made of plastic, and is typically injection molded as a single integral piece. According to some embodiments of the present invention, the tray insert is a plastic rib-tray insert, which rests on the bottom of the lower housing (which preferably is not itself stamped with ribs).
In the embodiment of
In the embodiment of
An advantage of a plastic rib-tray insert, as compared to a metal lower tray having stamped metal ribs, is that plastic ribs can be made with a much higher aspect ratio (i.e. the height of the rib versus the width of the rib) than metal ribs. Therefore, as compared to metal ribs, plastic ribs can block less fluid flow.
Another advantage of using a plastic tray insert over stamping ribs into the lower cover can be that the plastic insert can include an integral plastic inlet tube. Use of a plastic inlet tube provides design flexibility as compared to a separate metal inlet tube. For example, a plastic inlet tube can have cross-sectional geometries other than oval or round shapes. In addition, because the plastic inlet tube can be injection molded along with the tray insert, and can thus be an integral component of the tray insert, implementation problems associated with shaped or angled metal inlet tubes, which are crimped to the filter as a separate component, are alleviated. In addition, because the plastic tray insert can be used with metal and composite filters, a convenient alternative is provided for implementing shaped or angled inlet tubes without requiring the use of an all-plastic filter. An example of a filter incorporating a tray insert having an integral exemplary angled plastic inlet tube in accordance with the present invention is illustrated in
Another advantage of a plastic tray insert as compared to stamped metal ribs, is that the plastic tray insert can include a plastic inlet opening (including alternatively a plastic inlet tube), which can accommodate an anti-drainback device. Such devices can prevent or restrict fluid from flowing out of the filter when fluid is not being drawn into the filter. An example of a plastic inlet opening incorporating an anti-drainback device suitable for use with plastic tray inserts according to the present invention is illustrated in
A plastic tray insert can also accommodate “pass-through” pinch points. A “pinch point” is a location in the filter, where the upper cover and lower cover are designed to engaged one another in the interior (as opposed to edges) of the housing. For example, the top surface of a rib or projection which is stamped in the lower cover engages the bottom surface of a rib or projection which is stamped or molded in the upper cover. The purpose of the pinch point is to provide structural support to the housing to prevent or minimize deformations in the housing which may be caused when the filter is subjected to a vacuum. However, in prior art designs using stamped metal covers, the filter media (usually in bag configuration) is compressed at each such pinch point because the top and bottom of the filter bag are sandwiched between the top and bottom rib (i.e. the top of the bag is pushed against the bottom of the bag such that the bag is not held open at the pinch point), resulting in a loss of fluid flow area. A prior-art pinch point is illustrated in
According to some embodiments of the present invention, the plastic rib tray insert includes plastic “pass-through” pinch points, which are capable of holding the filter media (usually in bag configuration) open at the pinch point while simultaneously providing structural support. For example, the filter bag can be designed to have a hole through which a plastic pinch point can protrude. Accordingly, the filter bag is held open rather than compressed because only the top of the filter bag is compressed at the pinch point. Specifically, the top of the filter bag is sandwiched between the top of the plastic pinch point on the rib tray and the bottom of the pinch-point on the upper cover, while the bottom of the filter bag rests on the top of the rib tray. To prevent unfiltered fluid from mixing with filtered (clean) fluid, the filter bag can be sealed to the top of the ribtray (near the pinchpoint), by for example ultrasonic welding. An example of a pass-through pinch point suitable for use with plastic tray inserts according to the present invention is illustrated in
According to some embodiments of the invention, rather than resting on the bottom of the lower cover, the tray insert is suspended above the bottom of the lower cover and may be formed, for example, from plastic or metal. To suspend the tray insert, for example, the tray insert may have a bottom portion which includes vents to permit fluid flow and a lip portion spaced apart from the bottom portion by sides extending upward from the bottom portion. The lip portion of the tray insert is configured to rest on the lip portion of the lower cover, suspending the bottom portion of the tray insert above the bottom portion of the lower cover. In such embodiments, there is little or no lost flow area because there are no ribs integral with or adjacent the bottom of the lower cover to interfere with fluid flow.
In some embodiments, the suspended tray insert may also include legs which extend downward from the tray insert toward the bottom of the lower cover. Such legs can be made relatively thin as compared to the stamped metal ribs and accordingly, even where the legs may touch the lower cover, they may affect fluid flow to a lesser degree than the stamped metal ribs. For example, the legs may be the same thickness as the bottom of the tray insert, which is considerably thinner than the base of ribs which are stamped in the bottom of metal covers.
An embodiment of the present inventive apparatus is illustrated in
The tray insert 10 includes a filter media supporting surface 20, ribs 22 extending below the supporting surface 20 to the bottom portion 14 of the lower cover 12, pass-through pinch points 28, and an inlet opening 30.
The supporting surface 20 is formed from first linear segments 24 substantially oriented in the direction of fluid flow interconnected by second linear segments 26 substantially oriented perpendicular to the direction of fluid flow. Attached to the underside of the first linear segments 24 are the ribs 22 which offset the supporting surface 20 above the bottom portion 14 of the lower cover 12. Embodiments including ribs are sometimes referred to herein as “rib-tray inserts.”
The tray insert dimensions preferably correspond to the length and width of the filter media (usually in bag configuration). (The filter bag can be formed from filter media material having a length and width. The filter media material is folded in half along its length to form the filter bag. Thus the length of the filter bag is approximately half the length of the filter media material from which it is formed, and the width of the filter bag is approximately the same as the width of the filter media material from which it is formed.) Although
Generally, the length, number, distribution, and width of first linear segments 24 is chosen to be sufficient to provide a filter media supporting surface 20 that keeps the filter media spaced apart from the bottom portion 14 of the lower cover 12, while minimizing impact on fluid flow. For example, for stiff filter media, fewer first linear segments 24 are needed for support. The orientation of the first linear segments 24 is preferably in the direction of fluid flow, and the width of first linear segments 24 is preferably as narrow as possible, to alleviate any negative impact on fluid flow.
Generally, it is preferred to minimize the number of second linear segments 26 because second linear segments 26 can have a greater impact on fluid flow than the first linear segments 24 as they are not oriented in the direction of fluid flow. Preferably, the number, length, and orientation of second linear segments 26 are chosen to be sufficient to connect the first linear segments 24, providing structural support and integrity to the tray insert 10, but also minimize impact on fluid flow. As with the first linear segments 24, the second linear segments 26 are preferably made as narrow as possible.
The tray insert additionally includes plastic pinch points 28 and an inlet opening 30. As shown in
As best shown in
The inlet opening 30, as illustrated in
In some embodiments, the inlet opening 30 is as shown in
As is shown, the bottom portion 116 of the lower metal cover 112 is preferably stamped with channels 114 which receive the cross-bar segments 108. The depth of the channels 114 preferably correspond to the height of the cross-bar segments 108 so that when the cross-bar segments 108 are fitted into the channels 114, the top face of the cross-bar segments 108 lie in a plane substantially the same as the bottom portion 116 of the lower metal tray 112.
The ribs 104 divide the fluid traveling along the lower cover (toward the outlet) into channels. If one channel has a relatively high flow rate, gaps are provided in the ribs to allow fluid to “spill over” into the adjacent channel. The gaps cut out of the top 124 of the rib 104 also reduce the amount of media contact area at the top surface 124 of the rib 104 allowing a higher percentage of the media to be utilized (for filtration)
As with the embodiment illustrated in
Generally, the length, number, distribution, and width of interlinked ribs 104 is chosen to be sufficient to provide a filter media supporting surface 102 that keeps the filter media spaced apart from the bottom portion 116 of the lower cover 114, while minimizing impact on fluid flow. For example, for stiff filter media, fewer ribs 104 are needed for support. The orientation of the ribs 104 are preferably in the direction of fluid flow, and the width of interlinked ribs 104 are preferably as narrow as possible, to alleviate any negative impact on fluid flow.
Generally, it is preferred to minimize the number of cross-bar segments 108 because the cross-bar segments 108, as in the embodiment of
The inlet opening 110, as in the embodiment of
To assemble the oil filter 200, a filter bag, which includes an opening to coincide with inlet opening 110, is positioned on the tray insert 100. The filter bag, tray insert 100 and lower metal tray 112 are arranged so that the inlet openings 110, 204 align with each other. The filter bag can be bonded to the tray insert at the location of the inlet opening 110. For example, filter media material surrounding the opening may be ultrasonically welded to the inlet opening 110. Alternatively, a portion of the lower metal cover inlet opening 204 is crimped over the tray insert inlet opening 110 and the portion of the filter media surrounding the opening to the filter bag, attaching the three components to one another. The crimped metal from the inlet opening 204 is thus found in the interior of the filter bag. The upper cover 202 is then placed over the lower cover so that the lip portion 206 of the upper cover 202 rests on the lip portion 208 of the lower cover 112 and the two covers 202, 112 are then crimped together.
The pan can be, for example, plastic or metal material having holes 302 (also referred to as “cut-out portions” or “vents”) to permit fluid flow. The number, distribution, size, and shape of the cut-out portions are sized to adequately support the media thereby minimizing deflection toward the lower cover (which would block fluid on its way to the filter outlet) without reducing the fluid flow through the media. The localized flow rate through the media in areas that are supported by a rib 20, 301 is greatly reduced. Consequently, supporting the media too much will result in a higher pressure differential across the media and, therefore, through the filter. Preferably the pan is designed so that the surface area occupied by the pan material, such as the metal or plastic from which the pan is formed, is minimized, to reduce areas of lost fluid flow. Accordingly, the amount of material is preferably only so much as is needed to provide structural support and maintain the filter bag off the bottom portion 314 of the lower cover 312
As with the illustrated plastic rib-tray insert embodiments, when the embodiments of
Plastic tray inserts in accordance with the present invention can include plastic inlet tubes 31, as shown in
The many features and advantages of the invention are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope of the invention. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.
Number | Date | Country | |
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Parent | 10741448 | Dec 2003 | US |
Child | 11521402 | Sep 2006 | US |
Parent | 10741445 | Dec 2003 | US |
Child | 11521402 | Sep 2006 | US |