Abstract:
A spin-on fluid filter with improved attachment and sealing with the filter head. The filter has a gasket positioned at the end of threads used to connect the filter to a filter head. The described design protects the gasket from excessive engine heat, cut or tear damage during installation, and the roll out effect of installation torque. In addition, the described attachment provides gasket protection and uniform compression of the gasket. The gasket can be any type that provides a seal which keeps external threads on the filter and the filter head dry.

Description:
FIELD 
       [0001]    This disclosure describes a spin-on filter with improved attachment and sealing with an attachment structure. 
       BACKGROUND 
       [0002]    Conventional spin-on filters are provided with an external gasket that is disposed at or near the end of the filter that is intended to seal with a filter head on which the filter is mounted. However, the location of the gasket renders it susceptible to tearing or extrusion during installation of the filter. In addition, in some circumstances, the gasket can be exposed to excessive engine heat. 
       SUMMARY 
       [0003]    A filter is described that is attachable to an attachment structure, such as a filter head. The filter is designed to provide a protected shield for an internally disposed gasket which insulates the gasket from engine heat, contamination from threads during service, and installation damage. 
         [0004]    In one particular embodiment, the filter is a spin-on filter that is attachable to a filter head of an engine and that filters oil or other engine fluid. However, the concepts described herein can be applied to other types of filters, attachable to other attachment structures and that filter other fluids. 
         [0005]    The spin-on filter includes a threaded nutplate that threads onto suitably arranged threads on the head. The gasket is securely positioned within the attachment region of the nutplate of the filter which helps to maintain gasket retention during installation. 
         [0006]    In one embodiment, a recessed surface on the filter head helps to provide protection from water, dirt and road debris during operation. A radial seal, for example an o-ring or foam style seal, can also be utilized to provide added dust and debris protection. 
         [0007]    The engine filter head has external threads and a sealing surface at the end of the threads. In one embodiment, small radial rings can be provided on the sealing surface to provide a more robust sealing surface with no machining required. In one embodiment, the contact surface can be slightly recessed to allow the filter, when properly installed, to be slightly below the mounting surface and provide protection from water, dirt and road debris. 
         [0008]    The disclosed design also protects the gasket from excessive engine heat, cut or tear damage during installation, and the roll out effect of installation torque. In addition, the described attachment provides gasket protection and uniform compression of the gasket. The gasket can be, for example, a rectangular gasket, have a tapered face, an o-ring, an irregular gasket, and other shapes and designs that provide a seal which keeps external threads on the filter and the filter head dry. 
         [0009]    An adaptor can also be attached to the head using the same threads and sealing surface as the filter but incorporating a threaded center spud to allow the use of a conventional spin-on filter. This would seal below the threads in the same manner as described above as well as provide a seal for the center spud. 
     
    
     
       DRAWINGS 
         [0010]      FIG. 1  is a partial cross-sectional view of a filter described herein attached to a filter head. 
           [0011]      FIG. 2  is a partial cross-sectional, isometric view of a portion of the filter and the filter head during attachment, as the filter is being threaded onto the filter head. 
           [0012]      FIG. 3  is a partial cross-sectional, isometric view of a portion of the filter and the filter head during attachment, with the end of the filter about to enter the recess in the filter head. 
           [0013]      FIG. 4  is a partial cross-sectional, isometric view of a portion of another embodiment of a filter attached to the filter head, where the filter uses a tapered gasket and the filter head uses a corresponding tapered end. 
           [0014]      FIG. 5  is a cross-sectional view of the entire filter of  FIG. 1  with the filter completely installed on the head. 
           [0015]      FIG. 6  is a cross-sectional, isometric view of another embodiment of a filter. 
           [0016]      FIG. 7  is an isometric view of the nutplate of the filter of  FIG. 6 . 
           [0017]      FIG. 8  illustrates an adaptor attached to a head and a filter attached to the adaptor. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    With reference to  FIGS. 1 and 5 , a filter  10  is shown attached a filter head  12 . The filter head  12  can be disposed within an engine or other location for receiving the filter  10 . In one embodiment, the filter  10  is a lube filter that filters oil used by the engine. However, the filter  10  can be other types of filters used to filter other types of engine fluids, such as fuel or hydraulic fluids. In addition, the filter  10  can be used in non-engine applications and can be used to filter other types of fluid, including water or air. 
         [0019]    The filter  10  includes an outer shell  14  of metal or plastic. The shell  14  includes a closed end  15   a  ( FIG. 5 ) and an open end  15   b  that is closed by a nutplate  16 . The interior of the shell  14  is provided with filtration media  18  for filtering a fluid, for example oil, fuel, hydraulic fluid, or other fluid, that enters the filter  10  so as to be filtered. As would be understood by a person of ordinary skill in the art, the nutplate  16  has one or more inlet openings  19  (see  FIG. 2 ) that allow fluid to be filtered to enter the filter from an inlet region  20 . After being filtered, the filtered fluid flows out through a central outlet  22 . Further details on the general construction and operation of a spin-on type of filter can be found in U.S. Pat. No. 5,906,736 which is incorporated herein by reference in its entirety. 
         [0020]    With continued reference to  FIGS. 1 and 5 , the nutplate  16  includes a central opening  24  that is provided with a circumferential gasket  26  for sealing with an outlet tube  28  of the filter head  12 . The gasket  26  prevents mixing of unfiltered fluid with the filtered fluid. The gasket  26  is circumferentially continuous and faces radially inward. 
         [0021]    The nutplate  16  also includes an axially extending continuous rim  30  on the radial outer edge thereof. Internal threads  32  are formed on the internal surface of the rim  30 . The outer surface of the rim  30  is provided with a groove  34  into which the end of the shell  14  is deformed for connecting the shell and the nutplate  16 . A seal  36  disposed in a sealing groove on the rim  30  seals between the shell and the nutplate. 
         [0022]    A gasket seal  40  is disposed within a groove  42  formed at the base of the threads  32 . The groove  42  is formed between an inner surface of the rim  30  and a circumferential flange  44  that is formed on and projects upwardly from the upper surface of the nutplate. Alternatively, the groove  42  could be formed by a recess formed in the top surface of the nutplate or by other means. The gasket seal  40  provides a seal between the filter  10  and the filter head  12  to prevent fluid leakage to the outside of the filter. In use, the seal is circumferentially continuous and faces axially upwardly in a direction away from the closed end of the shell and toward the filter head. 
         [0023]    The filter head  12  includes an externally threaded flange  50  that is configured to engage with the threads  32  on the rim  30  for securing the filter  10  to the filter head  12 . The base  52  of the flange  50  is configured to engage with and compress the gasket  40 . In particular, with reference to  FIGS. 2 and 3 , the base  52  of the flange  50  includes one or more, for example three, radially spaced circumferential rings or flanges  54  on the bottom surface thereof and projecting downwardly from the bottom surface. The rings  54  help provide a more robust sealing surface. 
         [0024]    When the filter  10  is threaded onto the filter head  12 , the base  52  of the flange  50  engages and seals with the gasket  40 . The flange  50  axially compresses the gasket  40  during installation to enhance the seal. To limit compression of the gasket  40 , the filter head  12  is provided with a circumferential recess  56  that in use receives the end of the rim  30  as shown in  FIGS. 1 and 3 . The end of the rim  30  bottoming out in the recess  56  acts as a stop to limit over tightening of the filter  10  and over-compression of the gasket  40 . In addition, the recess  56  allows the end of the rim  30  to be slightly recessed below the mounting surface of the filter head to provide protection from water, dirt and road debris. 
         [0025]    In the embodiment illustrated in  FIGS. 1-3 , the gasket  40  is rectangular in cross-section. However, the gasket can be an o-ring, an irregular gasket, or have other shapes and designs that one finds suitable for providing the intended sealing function and any other functions of the gasket  40 . 
         [0026]    The gasket  40  can fill substantially the entire area of the groove  42 , or a small space can be provided between a side of the gasket  40  and the flange  44  or the inner surface of the rim  30  to allow expansion of the gasket  40  during compression. 
         [0027]    In an alternative embodiment shown in  FIG. 4 , the base  52  of the flange  50  can have a tapered or angled surface  60  that extends from a flat portion  62  containing one or more of the downwardly projecting annular rings  54 . The gasket includes a corresponding tapered or angled surface  64  that engages with the surface  60 , and a flat portion  66  that engages with the flat portion  62 . 
         [0028]      FIGS. 6 and 7  illustrate another embodiment of a filter  100  that is to be attached to a filter head (not shown). This embodiment differs from the embodiment illustrated in  FIGS. 1-5 , in that the sealing gasket for sealing with the outlet tube of the filter head is supported by a separate plate structure that is disposed between the filter and the nutplate, rather than being supported directly by the nutplate. 
         [0029]    The filter  100  includes an outer shell  114  having a closed end  115   a  and an open end  115   b  that is closed by a nutplate  116 . The interior of the shell  114  is provided with filtration media  118  for filtering a fluid, for example oil, fuel, hydraulic fluid, or other fluid, that enters the filter  100  so as to be filtered. 
         [0030]    A plate  117  is disposed between the nutplate  116  and the end of the filtration media  118  that has one or more inlet openings  119  that allow fluid to be filtered to enter the filter. After being filtered, the filtered fluid flows out through a central outlet defined by the plate  117 . 
         [0031]    The plate  117  includes a central opening defining the central outlet that is provided with a circumferential gasket  126  for sealing with an outlet tube of the filter head. The gasket  126  faces radially inward and prevents mixing of unfiltered fluid with the filtered fluid. 
         [0032]    The nutplate  116  also includes an axially extending continuous rim  130  on the radial outer edge thereof. Internal threads  132  are formed on the internal surface of the rim  130 . The outer surface of the rim  130  is provided with a groove  134  into which the end of the shell  114  is deformed for connecting the shell and the nutplate  116 . A seal  136  disposed in a sealing groove on the rim  130  seals between the shell and the nutplate. 
         [0033]    A gasket seal  140  is disposed within a groove  142  formed in the nutplate  116  at the base of the threads  132 . The groove  142  is formed between an inner surface of the rim  130  and a circumferential flange  144  that is formed on and projects upwardly from the nutplate  116 . The gasket seal  140 , which faces axially upward in a direction away from the closed end of the shell, provides a seal between the filter  100  and the filter head to prevent fluid leakage to the outside of the filter. 
         [0034]    In the embodiment illustrated in  FIGS. 1-3 , the gasket  140  is rectangular in cross-section. However, the gasket can be an o-ring, an irregular gasket, or have other shapes and designs that one finds suitable for providing the intended sealing function and any other functions of the gasket  140 . As shown in  FIG. 6 , the gasket  140  does not fill the entire space of the groove  142 . Instead, in this embodiment, a space is left between the outer perimeter of the gasket  140  and the inner surface of the rim  130  to allow expansion of the gasket  140  during compression. 
         [0035]    The filter  100  also includes an additional seal  146  disposed at the top of the shell  114  to seal between the shell and the nutplate  116 . 
         [0036]      FIG. 8  illustrates an adaptor  150  that is attached to a head  152  that can be used to attach the filter  100  to the head  152 . The adaptor  150  includes threads  156  that engage with threads on the head  152 , with an upper end  158  of the adaptor  150  extending into a circumferential recess  160  in the head  152 . A seal  162  can be provided at the upper end  158  to seal with the head. 
         [0037]    The adaptor  150  also includes a threaded intermediate section  164  that engages with the threads  132  of the filter  100 , and the gasket seal  140  of the filter engages with a bottom surface  166  of the intermediate section. A center outlet spud or outlet tube  168  extends downwardly from the intermediate section  164  in a direction away from the head  152 . The gasket  126  of the filter seals with the spud  168 . A sealing gasket  170  is also provided between outlet passage in the head  152  and an interior surface of the intermediate section  164  to seal incoming fluid to be filtered from the filtered fluid. 
         [0038]    Any of the individual features described with respect to  FIGS. 1-5 ,  6 - 7  and  8  can be used individually or in any combination with other features in  FIGS. 1-5 ,  6 - 7  and  8 , and the features in  FIGS. 1-5  can be used in any combination with the features described in  FIGS. 6-7  and  8 . 
         [0039]    The invention may be embodied in other forms without departing from the spirit or novel characteristics thereof. The embodiments disclosed in this application are to be considered in all respects as illustrative and not limitative. The scope of the invention is indicated by the appended claims rather than by the foregoing description; and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.