Abstract:
Mounting plates used to mount filter elements within cylindrical canisters are made from sintered powdered materials, such as sintered powdered metal in order to reduce engineering and tooling lead time as well as to reduce costs. By making a mounting plate of sintered metal, the mounting plate can have a varying thickness which is an advantage not obtainable with a mounting plate stamped from steel sheet

Description:
FIELD OF THE INVENTION 
     The present invention is directed to a filter container having a mounting plate made of sintered material. More particularly, the present invention is directed to a filter container for pressurized fluids, the filter container having a mounting plate made of sintered material. 
     BACKGROUND OF THE INVENTION 
     Filter containers for annular filter elements used to filter liquids such as hydraulic fluid, lubricating oil, and the like have mounting plates made of metal stampings for supporting annular filter elements. The metal stampings are usually made steel and require costly tooling which can not be provided quickly. Since the stamping are circular there is considerable waste which must be disposed of. Moreover, stampings limit mounting plates to plates of a constant thickness, which for high pressure applications frequently requires complex geometries in order to increase strength. Consequently, engineering and tooling efforts and as well costs for the mounting plates are relatively high and lead time for new designs is relatively long. In order to accommodate these limitations of stamped mounting plates, there is a tendency to avoid complex geometries, which geometries might be advantageous in configurations for filter mounting plates. 
     In view of these considerations, there is a need for a better way to configure mounting plates which does not have the disadvantages inherent in mounting plates configured by stamping. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a filter container having a filter element therein for supporting an annular filter media for filtering fluid used by a machine. The filter container comprises a cylindrical housing having a closed end and an open end. An annular mounting plate is positioned proximate the open end of the cylindrical housing and in accordance with the invention is molded of sintered metal and has a cross section of non-uniform thickness. The annular mounting plate supports the annular filter media thereon and has a central threaded opening therethrough for theadably coupling with a stand pipe of a machine using the fluid to be filtered. An annular cover is disposed over the annular mounting plate for holding the mounting plate in the housing, the cover being fixed to the housing at a peripheral portion of the housing. 
     In a further aspect of the invention, the mounting plate has unitary, spaced filter supports thereon defining channels therebetween, which channels allow fluid flow. 
     In still a further aspect of the invention, the spaced filter supports are lugs disposed adjacent the periphery of the plate and radially spaced from the threaded opening. And in still another aspect of the invention, the filter support are radially extending ribs. 
     In an additional aspect of the invention, the mounting plate includes a plurality of spaced holes therethrough, which are evenly spaced from the central opening to allow for circulation of fluid to or from the central opening after the fluid has passed through the filter media. 
     In still other aspects of the invention, the sintered metal is aluminum and weld projections are on the mounting plate to facilitate welding to the cover to the mounting plate. 
    
    
     BRIEF DESCRIPTIONS OF THE DRAWINGS 
     Various features and attendant advantages of the present invention will be more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein: 
     FIG. 1 is a side view, partially an elevation of the filter cartridge employing a mounting plate configured in accordance with the present invention; 
     FIG. 2 is an end view of the filter cartridge of FIG. 1; 
     FIG. 3 is a side elevation of a mounting plate and cover used with the filter cartridge of FIGS. 1 and 2; 
     FIG. 4 is an end view of the mounting plate and cover shown in FIG. 3 with the cover positioned thereover; 
     FIG. 5 is a perspective view of only the mounting plate shown in FIGS. 3 and 4; 
     FIG. 6 is a planar view of one side the mounting plate of FIG. 5; 
     FIG. 7 is a planar view of the other side of the mounting plate of FIGS. 5 and 6; 
     FIG. 8 is a side elevation of the mounting plate of FIGS. 5-7 shown without the cover; 
     FIG. 9 is a side view in perspective with portions cut away of a second embodiment of a filter cartridge utilizing a filter container having a mounting plate configured in accordance with the principals of the present invention; 
     FIG. 10 is a perspective view of another embodiment of a mounting plate made of sintered metal in accordance with the principals of the present invention, and 
     FIG. 11 is a perspective view of still another embodiment of a mounting plate made of sintered metal in accordance with the principles of the present invention. 
    
    
     DETAILED DESCRIPTION 
     Referring now to FIGS. 1 and 2, and canister  10  encloses filter element  12  within a container  14 , wherein the container  14  inncludes a cylindrical housing  16  having first end  18  closed by a dome  20  and a second end  22  in which is disposed an annular mounting plate  24  made of sintered material in accordance with the principals of the present invention. The filter element  12  is biased by a coil spring  26  into abutment with a filter support  28 , which filter support is unitary with a substantially flat plate portion  29  of annular mounting plate  24 . 
     The annular mounting plate  24  has a central opening  30  therethrough which has a helical thread  32  for receiving a conventional externally threaded stand pipe (not shown) of a hydraulic machine (not shown). The conventional threaded stand pipe includes a nipple (not shown) which is inserted within an eleastic glomet  34  in the filter element  12  to provide a liquid return. In operation, the liquid flows through openings within the stand pipe (not shown), past the filter supports  28  and into an annular space  36  before passing through the filter element  12  and into the core  38  of the filter element where it flows out through the nipple (not shown) of the stand pipe (not shown) sealed by the resilent gloment  34 . In order to provide for this flow pattern of hydraulic fluid, the annular mounting plate  24  has the features set forth in FIGS. 3-8. 
     Referring now to FIGS. 3-8, it is seen especially in FIGS. 3,  5 ,  6  and  8  that the filter support  28  comprises lugs  40  which are unitary with the mounting plate  24  and are separated by spaces  42 , the spaces  42  providing gaps through which oil can flow as it enters the filter cartridge  10  (FIG. 1) through the central opening  30  of the mounting plate  24 . 
     A cover  46  fits over the outwardly facing surface  48  of the mounting plate  24 , the cover having a peripheral portion  50  which crimps with the second end  22  of the cylindrical housing  16 . As is seen in FIGS. 7 and 8, the outwardly facing surface  48  of the mounting plate  24  has welding points  52  which provide a welding area so that the mounting plate  24  forms an assembly with the cover  46 , which an assembly facilitates assemblage of the container  14  with the filter element  12  therein to form the filter cartridge  10 . While welding points  52  are preferred, the cover  46  may be attached to the mounting plate  24  in other ways such as being crimped, press fit, bonded with adhesive or even screwed or bolted. 
     As is readily seen in FIG. 8, the mounting plate  24  does not have a constant cross section because the lugs  40  have a thickness in the axial direction which is greater than the thickness of the plate portion  29  of the mounting plate. In addition, the helical thread  32  is formed in the wall of the opening  30 , while the projections  52  are formed on the surface  48 . These are not structures which could not be formed by stamping a sheet metal plate since these structures do not have the same cross-sectional thickness in the axial direction as the plate portion  29 . Moreover, it would be impossible to form the helical thread  32  by stamping. To accomplish the illustrated profile, the present invention forms the mounting plate  24  by sintering powdered metal. A preferable powdered metal is a powdered mixture of iron and copper. Other suitable powdered metal mixtures may be used, for example, powdered mixtures of iron including brass, bronze and stainless steel. Aluminum, which includes appropriate powdered oxides could be used, but may require a threaded steel insert for the helical thread  32 . Parts made of sintered powdered aluminum have greater strength than parts made of cast aluminum or stamped from aluminum sheet. The mounting plate  24  may also be made of other sintered materials, such as but not limited to ceramic sintered materials or sintered powdered metals such as sintered steels which include for example iron carbon steel, iron copper steel, iron nickel steel or low alloy steel. 
     Referring now to FIGS. 9,  10  and  11 , there are shown mounting plates  62 ,  64  and  66 , respectively, each made of sintered materials such as the preferred iron and copper powder mixtures or the other mixtures of this application as well as mixtures not mentioned. Note in FIGS. 9 and 11 that the mounting plates  62  and  66  do not have a uniform thickness and that the mounting plate of FIG. 11 has a complex geometry provided by ribs  68  of varying thickness and a hub  70  which is displaced from a ring portion  72  by a plurality of openings  74 . It would be impossible to stamp the structure of FIG. 11 from a sheet of steel because of the varying thicknesses. Also note that in FIG. 9, the mounting plate  62  may have an internally threaded steel insert  76  and that the mounting plate  66  of FIG. 11 may have an internally threaded steel insert  78  if these mounting plates are made of aluminum. If the mounting plates are made of harder materials, the threaded inserts are formed during molding. 
     In FIG. 10, the mounting plate  64  has plurality of spaced small openings  80  and has a relatively uniform thickness except adjacent a central port  81  which has a raised rim  82 . Again, there is shown in FIG. 10 a structure which cannot be stamped from a single sheet but can be molded of sintered metal. 
     The mounting plates  24 ,  62 ,  64  and  66  of FIGS.  5  and  9 - 11  are each formed by making molds of readily machinable or formed materials and then using the molds to quickly form sintered metal mounting plates of different mounting plate designs and configurations quickly and at reduced costs. This is because the molding process involves merely pressing the powdered metal in a mold and then heating the resulting molding to bond the pressed particles to one another. From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions.