Patent Publication Number: US-2022226757-A1

Title: Top and bottom loaded filter and locking mechanism

Description:
TECHNICAL FIELD 
     This application is a divisional application of application Ser. No. 16/799,193, filed on Feb. 24, 2020, having the same title, claiming priority thereto and incorporating its contents herein by reference in its entirety. 
     TECHNICAL FIELD 
     The present disclosure relates generally to canister style filter systems that employ a replaceable filter element. More specifically, the present disclosure relates to a filter element that includes a locking feature for retaining the filter element in a desired position while providing a seal that helps to ensure that dirty fluid is filtered by the filtering medium of the filter element. 
     BACKGROUND 
     Liquid filter systems are known for filter various fluids such as gas, oil, diesel fuel, etc. to remove contaminants from these fluids. In diesel engines, for example, a fuel line filter is used to separate out water and debris from the fuel. These contaminates may accumulate in a lower portion of the filter housing (may also be referred to as a canister). Typically, the center tube of the filter element provides support for the filter media but may not always provide the desired location and retention. 
     U.S. Pat. Application Publication No. 20060207948 to Hacker et al. discloses a fluid filter assembly including a housing, a service cover, a center tube removably secured to the service cover, and a filter cartridge removably sealed and circumscribing the center tube, and a seal arrangement. The seal arrangement is between the center tube and portions of the housing to close a drainage change to the flow of a clean fluid flow therethrough, when the fluid filter assembly is operating to filter the fluid. 
     During normal operation in Hacker, the fluid filter assembly operates to allow fluid to flow into the housing through an inlet channel, through the filter cartridge, through openings in the center tube, and out of the housing through the outlet channel. Methods for servicing include removing a service cover from a housing to remove, together with the service cover, a center tube, and open a drainage flow passageway from the housing. Next a filter cartridge is removed from the center tube, and a new filter cartridge is operably mounted on the center tube. Next, the service cover with the center tube having the new filter cartridge is operably mounted in the housing to close the drainage flow passageway. 
     In Hacker, methods of filtering will direct fluid to be filtered into a housing having a removable and replaceable filter cartridge; then direct the fluid through a tubular region of filter media in the cartridge; then through fluid openings in a center tube; and into a clean fluid flow passageway. Example methods include preventing fluid to bypass the filter media by removably sealing the filter cartridge to the center tube. Example methods will also include preventing fluid from flowing into a drainage passageway by removably sealing the center tube to other portions of the filter housing. Systems utilizing filter assemblies described in Hacker include fuel systems, lube systems, and hydraulic systems. 
     Hacker fails to disclose a feature on the center tube that may be used to both position and retain the filter element in a desired position while also providing a seal that forces dirty fluid to pass through the filter medium of the filter element before exiting the filter element. 
     SUMMARY OF THE DISCLOSURE 
     A filter element that includes at least a partially annular configuration and that defines a longitudinal axis, a radial direction, and a circumferential direction according to an embodiment of the present disclosure is provided. The filter element may comprise an annular filter media defining a central passage, a center tube that is disposed in the central passage of the annular filter media that defines a central reservoir, and the annular filter media surrounds the center tube and the central reservoir. A top open end may be joined to the center tube disposed along the longitudinal axis, the top open end including an opening allowing fluid to flow from the central reservoir to the outside of the filter element. A bottom open end may be joined to the center tube opposite the top open end disposed along the longitudinal axis, the bottom open end defining a radially outer surface and a radially inner surface that is in communication with the central reservoir. A first locking feature may be disposed proximate to the bottom open end, the first locking feature including a first entrance slot that is disposed on the radially inner surface of the center tube extending axially upwardly from the bottom open end, and a first ramp slot extending axially upwardly and circumferentially counterclockwise from the first entrance slot along a first predetermined direction, the first ramp slot being in communication with the first entrance slot. A second locking feature may be disposed proximate to the top open end, the second locking feature includes a second entrance slot that is disposed on the radially inner surface of the center tube extending axially downwardly from the top open end, and a second ramp slot extending axially downwardly and circumferentially clockwise from the second entrance slot along a second predetermined direction, the second ramp slot being in communication with the second entrance slot. 
     A pair of pedestals for use with a canister filter system and a filter element according to an embodiment of the present disclosure is provided. Each of the pair of pedestals may comprise an at least partially annular body defining a longitudinal axis, a radial direction, and a circumferential direction, and may include a top annular portion terminating at a top free end, and a tab extending radially from the top annular portion, the tab including a first axial surface, a bottom circumferential surface, and a bottom ramp surface extending from the bottom circumferential surface. 
     A canister filter system according to an embodiment of the present disclosure may comprise a filter element that includes at least partially a cylindrical configuration and that defines a longitudinal axis, and a radial direction. The filter element may comprise an annular filter media defining a central passage, a center tube that is disposed in the central passage of the annular filter media that defines a central reservoir, and the annular filter media surrounds the center tube and the central reservoir. A top open end may be joined to the center tube disposed along the longitudinal axis, the top open end including an opening allowing fluid to flow from the central reservoir to the outside of the filter element, and a bottom open end may be joined to the center tube opposite the top open end disposed along the longitudinal axis. A canister may be provided that includes a top open end, and a bottom closed end or a bottom open end disposed along the longitudinal axis. A base that is configured to be attached to the canister may also be provided, as well as a bottom pedestal including an at least partially annular body defining a longitudinal axis, a radial direction, and a circumferential direction. The bottom pedestal may include a top annular portion terminating at a top free end and defining a top diameter, a bottom annular portion defining a bottom diameter that is greater than the top diameter, and a bottom tab extending radially from the top annular portion. The bottom pedestal may rest on the bottom closed end of the canister, and the filter seal may be disposed below the tab of the bottom pedestal and around the bottom annular portion while contacting the canister. A top pedestal may also be provided that comprises a top tab, the top pedestal being operatively associated with the base. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front sectional view of a filter assembly that includes a filter base, a canister, and a filter element including a center tube with a locking feature according to an embodiment of the present disclosure, and a pedestal that is configured to mate with the locking feature. 
         FIG. 2  is a front sectional view of the bottom portion of a filter assembly similar to that of  FIG. 1  with the annular filter media removed, showing the mating of the pedestal with the locking feature of the center tube according to an embodiment of the present disclosure. 
         FIG. 3  is a perspective view of the filter assembly of  FIG. 2  illustrating how the pedestal rests or extends from the bottom of the canister. 
         FIG. 4  is an enlarged perspective view of the mating of the tab of the pedestal with the locking feature of the center tube. 
         FIG. 5  shows the canister and pedestal shown in isolation from the filter assembly of  FIG. 3 . 
         FIG. 6  is a bottom oriented perspective view of the filter seal showing its aperture that is configured to mate with the cylindrical or conical surface of the pedestal. 
         FIG. 7  is a perspective view of the center tube shown in isolation from the filter assembly of  FIG. 1 . 
         FIG. 8  is a perspective view showing conceptually how a center tube such as the one similar in construction to the center tube of  FIG. 7  may be configured to mate with the base at the top end and the pedestal at the bottom end of a filter assembly. 
         FIG. 9  is an enlarged detail view showing the mating of the locking slot of the center tube and pedestal similar to the bottom portion of  FIG. 8  except the pedestal is shown near the top in  FIG. 9 . The tab of the pedestal is shown being rotated during an assembly or locking operation. 
         FIG. 10  illustrates that the tab of the pedestal of  FIG. 9  is small enough to fall into the detent notch. 
         FIG. 11  is an enlarged detailed view showing the mating of the locking slot of the center tube and pedestal similar to the top portion of  FIG. 8 . The tab of the pedestal is shown to be too large to fit into the detent notch. 
         FIG. 12  is a flow chart containing a method of operation or assembly associated with  FIGS. 9  thru  10 . 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to embodiments of the disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. In some cases, a reference number will be indicated in this specification and the drawings will show the reference number followed by a letter for example,  100   a,    100   b  or a prime indicator such as  100 ′,  100 ″ etc. It is to be understood that the use of letters or primes immediately after a reference number indicates that these features are similarly shaped and have similar function as is often the case when geometry is mirrored about a plane of symmetry. For ease of explanation in this specification, letters or primes will often not be included herein but may be shown in the drawings to indicate duplications of features discussed within this written specification. 
     First, a filter system will now be described to give the reader the proper context for understanding how various embodiments of the present disclosure are used. It is to be understood that this description is given as exemplary and not in any limiting sense. Any embodiment of an apparatus or method described herein may be used in conjunction with any filter system. 
     Then, a filter element that may include a center tube with a locking feature according to various embodiments will be discussed. This feature may be located in the bottom end of a liquid filter assembly with a reusable housing (may be referred to as a canister), and it may position the filter element radially and axially in the canister (may also be referred to as the housing) while also separating the clean fluid from the dirty fluid on different sides of the filter medium via a seal. In fuel-water separators, the positioning geometry may be configured to create a chamber for collecting water (i.e. a water bowl) or debris by preventing the element from extending to the bottom of the canister. 
       FIG. 1  illustrates a canister filter system  100  that may use a filter element  200 , and a pedestal  300  according to various embodiments of the present disclosure. 
     The canister filter system  100  may include having a base  102  (shown to be split up into a base adapter  102 a and a filter base  102 b, but could be one integral component), a canister  104 , a pedestal  300 , and a filter element  200 . The canister filter system  100  may be used to filter fluids such as diesel or gasoline or other liquid fuels, lubrication oil, hydraulic fluid for hydraulic power systems, transmission fluid, or even possibly intake air for an engine. The canister filter system  100  may also be used as a fuel/water separator filter. The canister filter system  100  with the features described herein could be adapted by those of ordinary skill in this art to serve many different purposes and suit many other applications. 
     The base  102  includes an inlet channel  106  for fluid to enter into the canister filter system  100 , and an outlet channel  108  for fluid to exit from the canister filter system  100 . A clip  110  is provided to attach the canister  104  to the base  102 . Other attachment structure such as threads may be used. 
     The canister  104  includes a top open end  112  and a bottom open end  114  as shown in  FIG. 1  or a bottom closed end  116  as shown in  FIGS. 2 and 3 . 
     The filter element  200  may take many different forms to suit a particular application. In the illustrated embodiment, the filter element  200  is well suited for filtering fuel or lubrication oil. The filter element  200  may include annular filter media  202  circumferentially surrounding a central reservoir  204  defined by a center tube  206 . Axial ends of annular filter media  202  are shown to be sealed by end caps. 
     A top end cap  208  may define an axial open end of filter element  200 . The top end cap  208  is termed “open” because it includes an opening  210  for allowing passage of fluid. 
     On the other hand, the bottom end cap  212  defines an axial closed end of filter element  200 . The bottom end cap  212  is termed “closed” because it prevents any fluid outside the filter element  200  adjacent the axial end of the annular filter media  202  from flowing unfiltered into center tube  206 . 
     The top end cap  208  and the bottom end cap  212  may each be joined to the center tube  206  via welding, adhesives, etc. Alternatively, several or all of center tube  206 , the top end cap  208 , and the bottom end cap  212  may be constructed as unitary components. Conversely, the bottom end cap  212  and/or the top end cap  208  may be separate components from the center tube  206 , etc. Further details of the closed configuration of the bottom of the canister filter system  100  and the filter element  200  will be discussed later herein. 
     In operation, fluid to be filtered enters from the inlet channel  106  and flows to the annular cavity  118  between canister  104  and the annular filter media  202 . The fluid then passes into and through filter media  202 , then into the center tube  206  through the perforations  214  shown therein in  FIG. 1 . 
     Then, the fluid exits center tube  206  through the top end cap  208  and opening  210  into the outlet channel  108 . The sealed construction at the bottom of the filter element  200  helps to define the fluid channels into and out of the annular filter media  202 , preventing any fluid from flowing directly to outlet channel  108  and bypassing the annular filter media  202 . To that end, sealing features may be provided that will be discussed in detail later herein. Moreover, it may be desirable to create a chamber (e.g. a water bowl in fuel-water separators, a drain reservoir, etc.) between the bottom of the filter element and the bottom of the canister. So, a positioning feature may be provided as will be discussed later herein. 
     Referring now to  FIGS. 1  thru  3 , a canister filter system  100  according to various embodiments of the present disclosure that provides locking and/or positioning feature(s) will now be discussed. 
     The canister filter system  100  may comprise a filter element  200  that includes at least partially a cylindrical configuration and that defines a longitudinal axis  216 , a circumferential direction  217 , and a radial direction  218 . The filter element  200  may comprise an annular filter media  202  defining a central passage  219  and a center tube  206  that is disposed in the central passage  219  of the annular filter media  220  that defines a central reservoir  204 . Thus, the annular filter media  202  surrounds the center tube  206 , and the central reservoir  204 . 
     As best seen in  FIG. 1 , the filter element  200  may further include a top open end  220  joined to the center tube  206  disposed along the longitudinal axis  216 . The top open end  220  includes an opening  210  that allows fluid to flow from the central reservoir  204  to the outside of the filter element  200 . 
     Similarly, the filter element  200  may include a bottom open end  222  joined to the center tube  206  opposite the top open end  220  that is also disposed along the longitudinal axis  216 . Thus the bottom open end  222  allows insertion of the pedestal  300 . 
     The canister filter system  100  may also include a canister  104  that includes a top open end  112  (see  FIG. 1 ), and a bottom closed end  116  (see  FIGS. 2 and 3 ) relative to the longitudinal axis  216 , and a pedestal  300  that rests on the bottom closed end  114  of the canister  104 . This may not be the case in other embodiments of the present disclosure such as in  FIG. 1  wherein the pedestal  300  is molded integral with the canister  104 . 
     Looking now at  FIGS. 2  thru  5 , the pedestal  300  may include an at least partially annular body  302  (may be completely annular with a thru-hole  304  extending from end to end as best seen in  FIG. 5  or not such as shown in  FIG. 1 ) defining a longitudinal axis  306 , a radial direction  308 , and a circumferential direction  310  (see  FIG. 5 , may be concentric with the filter element once assembled). 
     Focusing on  FIG. 5 , the body  302  may include a top annular portion  312  terminating at a top free end  314  (regardless of whether it is open or closed) and may also define a top diameter  316  (i.e. top outer diameter), and a bottom annular portion  318  defining a bottom diameter  320  (i.e. bottom outer diameter) that is greater than the top diameter  316 . 
     A tab  322  may extend radially from the top annular portion  312 , and a filter seal  120  may be provided that defines an aperture  122  that is configured to mate with the bottom annular portion  318  of the pedestal  300  (see also  FIG. 6 ). 
     With continued reference to  FIG. 5 , the pedestal  300  may rest on the bottom closed end  114  of the canister  104 . The filter seal  120  may be disposed below the tab  322  of the pedestal  300  and around the bottom annular portion  318  while contacting the canister  104 . 
     More specifically, the canister  104  comprises an outer annular wall  124  that defines an outer diameter  126  (see  FIG. 1 ) that is greater than the bottom diameter  320  of the pedestal  300 , a support wall  128  that is configured to support the bottom annular portion  318  of the pedestal  300 , and an arcuate wall  130  (other configurations are possible) that connects the support wall  128  to the outer annular wall  124  (see  FIG. 5 ). 
     As shown in  FIG. 3 , the filter seal  120  may contact the arcuate wall  130 , forming a drain reservoir  132 . More particularly, the bottom open end  222  of the center tube  206  may impinge upon the filter seal  120 , creating a fluid tight seal between center tube  206  and the filter seal  120 , and another fluid tight seal between the filter seal  120  and the arcuate wall  130  of the canister  104 . 
     Looking at  FIG. 6 , a ratio of the outer diameter  136  to the thickness  134  of the filter seal  120  of the filter seal may range from 10.0 to 30.0, while a ratio of the outer diameter  136  to the hole diameter  137  may range from 1.5 to 3.0. This geometry in addition to the elastomeric composition of the filter seal may provide the suitable balance between rigidity and flexibility to allow the center tube and pedestal to be connected while providing the water tight seals. For example, a material of urethane having a durometer of 55 to 65 Shore A (e.g. 60 Shore A) may be employed. 
     Looking at  FIGS. 2  thru  4 , the center tube  206  includes a locking slot  224  that extends axially from the bottom open end  222  of the center tube  206  an axial distance  226 , and then extends circumferentially a circumferential distance  228 . 
     Referring to  FIGS. 3 and 5 , the center tube  206  may define an inner diameter  230  that is slightly greater (i.e. 0.015 of an inch to 0.030 an inch of clearance) than the top diameter  316  of the pedestal  300  that is disposed within the inner diameter  230 , and the tab  322  of the pedestal  300  may be disposed in the locking slot  226 , and may be configured to guide the movement of the center tube  206 . This arrangement may provide a positioning/centering function. Though not shown, an  0 -ring or other seal may be provided at this interface  138  to prevent fluid from bypassing the annular filter media  202  in some embodiments such as when the annular filter media does not extend axially past the locking slot. 
     As best seen in  FIG. 5 , the pedestal  300  may include a flared annular portion  324  (e.g. a conical shape, an arcuate shape, etc.) that connects the top annular portion  312  to the bottom annular portion  318 . This feature may be omitted in other embodiments. As best seen in  FIG. 6 , the radially inner surface  234  of the center tube  206  may have a matching shaped (e.g. angled or tapered) to ease installation of the center tube/filter element onto the pedestal. This may provide guidance as the tabs enter the locking slots. 
     Referring once more to  FIG. 5 , the bottom annular portion  318  may be attached to the canister  104 . For example, when the canister and the pedestal are formed by thermoplastic injection molding (e.g. using a polyruethane material, nylon material, etc.), the pedestal may be ultrasonically welded to the canister, molded integrally with the canister, snapped onto the canister, threaded onto the canister etc. Also, a protuberance may extend from the canister about which the pedestal is centered, etc. Other manufacturing methods are possible including sheet metal fabrication, etc. When metal is employed, the pedestal may be attached to the canister via welding, brazing, threading, etc. 
     The bottom annular portion  318  may define at least one thru-slot  326  that extends radially and possibly axially downwardly through the bottom annular portion  318 . This may allow water or debris to exit from the central reservoir  204  of the center tube  206  to the drain reservoir  132  (e.g. see  FIG. 3 ). 
     Now, a filter element  200  that may be used with the that includes at least a partially annular configuration (e.g. conical, cylindrical, other bodies of revolution, etc.) and that may be used with the canister filter system  100  just described will be discussed with reference to  FIGS. 1  thru  4 , and  7 . 
     Starting with  FIGS. 1 and 7 , the filter element  200  may define a longitudinal axis  216 , a radial direction  218 , and a circumferential direction  217 . Moreover, the filter element  200  may comprise an annular filter media  202  defining a central passage  219 . 
     A center tube  206  may be disposed in the central passage  219  of the annular filter media  202  that defines a central reservoir  204 . Accordingly, the annular filter media  202  surrounds the center tube  206  and the central reservoir  204 . A top open end  220  may be joined to the center tube  206  that is disposed along the longitudinal axis  216 . The top open end  220  includes an opening  210  allowing fluid to flow from the central reservoir  204  to the outside of the filter element  200  or vice versa. 
     Similarly, a bottom open end  222  may be joined to the center tube  206  axially opposite the top open end  220  disposed along the longitudinal axis  216 . As best seen in  FIG. 3 , the bottom open end  222  may define a radially outer surface  232 , and a radially inner surface  234  that is in communication with the central reservoir  204 . 
     Looking at  FIGS. 2  thru  4 , a locking feature  236  may be disposed proximate to the bottom open end  222  of the center tube  206 . The locking feature  236  may include an entrance slot  238  that is disposed on the radially inner surface  234  of the center tube  206  that extends axially upwardly from the bottom open end  222 . This entrance slot is configured to allow the center tube  206  to slide over the tab  322  of the pedestal  300  alluded to earlier herein during assembly. 
     As best seen in  FIG. 4 , the locking feature  236  may further comprise a ramp slot  240  that extends axially upwardly and circumferentially counterclockwise from the entrance slot  238  along a predetermined direction  241 . The ramp slot  240  is in communication with the entrance slot  238  so that as the tab  322  of the pedestal  300  moves upwardly in the entrance slot  238  when the center tube  206  moves downwardly, the tab  322  will eventually arrive at the ramp slot  240 . Twisting the center tube  206  circumferentially will cause the center tube  206  to move downwardly, impinging upon the filter seal  120  (e.g. see  FIG. 3 ). In other embodiments, this arrangement may be reversed such that the ramp slot extends axially upwardly and circumferentially clockwise. In such a case, the center tube will need to be twisted in the opposite direction. 
     With continued reference to  FIG. 4 , the locking feature  236  may further comprise a circumferential locking slot  242  that extends circumferentially counterclockwise from the ramp slot  240 . The circumferential locking slot  242  is in communication with the ramp slot  240 , and terminates at a stop surface  244 . Consequently, as the center tube  206  is twisted circumferentially, the axial position of the center tube is substantially fixed by the tab  322  of the pedestal  300 . Again, this arrangement may be reversed such that the circumferential locking slot extends in the clockwise direction, necessitating that the center tube be rotated in the opposite direction. 
     Continued twisting of the center tube  206  in the counterclockwise direction will allow the tab  322  to contact or nearly contact the stop surface  244 , at which time the upward force exerted by the filter seal  120  causes the center tube  206  to move slightly upwardly until the tab  322  engages a detent notch  246  that extends axially downwardly from the circumferential locking slot  242  being in communication therewith. Now, the center tube  206  is locked into position both axially, radially and circumferentially against unintentional movement. 
     An angled surface  248  may extend from the detent notch  246  to the stop surface  244 , matching the shape of the tab  322 . Hence, the angled surface  248  may parallel to the predetermined direction  241  that the ramp slot  240  extends. Likewise, the stop surface  244  may extend axially to match shape of the tab  322 . 
     Other configurations are possible for these various features. 
     Looking at  FIGS. 4 and 7 , the center tube  206  has a necked down configuration at the bottom open end  222  including an enlarged bottom annular portion  248 , a reduced top annular portion  250 , and a transitional annular portion  252  therebetween. The entrance slot  238  is formed by the enlarged bottom annular portion  248 , and the transitional annular portion  252 . The ramp slot  240  is formed by the transitional annular portion  252 , and the reduced top annular portion  250 . The circumferential locking slot  242 , and the detent notch  246  are formed by the reduced top annular portion  250 . 
     Again, other configurations for these features are possible in other embodiments of the present disclosure. 
     Looking at  FIG. 7 , it can be seen that the center tube  206  (and therefore the filter element  200 ), are constructed so that both ends are similarly or identically constructed. So, the center tube  206  may be rotated about an axis that extends through axial midpoint of the center tube and perpendicular to the longitudinal axis  216  an amount of 180 degrees and still be able to be installed with the pedestal  300 . This may not be the case in other embodiments of the present disclosure. In such a case, the top locking feature may or may not be used to attach the base to the center tube. An example, of the use of both top and bottom locking features in a canister filer system will be discussed later herein. 
     The top portion of the entrance slot  238 , and the entirety of the ramp slot  240 , the circumferential locking slot  242 , and detent notch  246  extend completely radially through the center tube  206 . On the other hand, the lower portion of the entrance slot  238  does not extend completely radially through the center tube  206  (denoted by dotted lines). Thus, a side action may form the thru-portions of these features while a bottom core may form the blind portion of the entrance slot and contacts the side action. So, the center tube may be manufactured using a thermoplastic injection molding process. A nylon, a polyurethane, or any other suitable material may be used to form the center tube. 
     Other configurations for these features may be employed to facilitate the use of other manufacturing processes, etc. 
     Next, a pedestal  300  that may be used with a canister filter system  100 , and a filter element  200  for positioning and retaining the filter element  200  in the canister filter system  100  will now be discussed with reference to  FIGS. 4 and 5 . 
     The pedestal  300  may comprise an at least partially annular body  302  defining a longitudinal axis  306 , a radial direction  308 , and a circumferential direction  310 . 
     The body  302  may include a top annular portion  312  terminating at a top free end  314  as earlier described herein. A tab  322  extends radially from the top annular portion,  312 . The tab  322  includes a first axial surface  328 , a bottom circumferential surface  330 , and a bottom ramp surface  332  extending from the bottom circumferential surface  330 . The first axial surface  328  is configured to engage a surface of the entrance slot  238 , the bottom circumferential surface  330  is configured to engage a surface of the circumferential locking slot  242 , and the bottom ramp surface  332  is configured to engage a surface of the ramp slot  240  of the center tube  206  as previously described herein. 
     In addition, the tab  322  further comprises a top ramp surface  334  extending from the first axial surface  328  that is parallel to the bottom ramp surface  332  for engaging another surface of the ramp slot  240 . A top circumferential surface  336  extends from the top ramp surface  334  that engages another surface of the circumferential locking slot  242 . A second axial surface  338  connects the bottom ramp surface  332  to the top circumferential surface  336 , and is configured to engage the stop surface  244  of the center tube  206 . 
     The pedestal  300  may be complimentarily shaped to the bottom open end  222  of the center tube  206 . Consequently as seen in  FIG. 5 , the pedestal  300  may have a bottom annular portion  318  that defines a bottom diameter  320 , and a top annular portion  312  that defines a top diameter  316  that is less than the bottom diameter  320 . Also, a flared annular portion  324  (may also be referred to as a funnel annular portion) connects the top annular portion  312  to the bottom annular portion  318 . 
     The pedestal  300  may further comprise a canister portion  340  (e.g. may be attached thereto) and may include an annular outer wall  342  defining an outer diameter  344  that is greater than the bottom diameter  320  of the bottom annular portion  318  to form the annular cavity  118  (see  FIG. 1 ). As best seen in  FIG. 5 , a support wall  346  that is configured to support the bottom annular portion  318 , and a funnel wall  348  connecting the annular outer wall  342  to the support wall  346 . 
     Looking at  FIGS. 1, 7 and 8 , it may be understood that the canister filter system  100  and its center tube  206  may be modified so that the center tube  206  has both top and bottom locking features for attaching both the base  102  and the canister  104  to the filter element  200 . As shown in  FIG. 8 , a top pedestal  300  may be provided that is identically configured to that of  FIG. 5  except that it has been rotated 180 degrees about an axis passing through the axial midpoint of the center tube  206  and that is perpendicular to the longitudinal axis  216  of the center tube  206  so that the top pedestal  300  may be operatively associated with the base  102  instead of the canister  104  (e.g. attached to the base instead of the canister as previously described herein). 
     In  FIG. 8 , a bottom pedestal  300 ′ may be provided that includes an at least partially annular body  302 ′ defining a longitudinal axis  306 ′, a radial direction  308 ′, and a circumferential direction  310 ′ that are defined the same way as those of the top pedestal  300 . 
     The bottom pedestal  300 ′ may include a top annular portion  312 ′ that terminates at a top free end (not clearly shown but understood to be similar to what has been previously described for pedestal  300  or what is shown in  FIG. 1 ), and that defines a top diameter (not clearly shown but understood to be similar to what has been previously described for pedestal  300  or what is shown in  FIG. 1 ). Likewise, the bottom pedestal  300 ′ may also include a bottom annular portion  318 ′ defining a bottom diameter (not clearly shown but understood to be similar to what has been previously described for pedestal  300  or what is shown in  FIG. 1 ) that is greater than the top diameter  316 ′. A flared annular portion  324 ′ that connects the top annular portion  312 ′ to the bottom annular portion  318 ′. Also, a bottom tab  322 ′ extends radially from the top annular portion  312 ′. 
     The bottom annular portion  318 ′ may define at least one thru-slot (not clearly shown but understood to be similar to what has been previously described for pedestal  300 ) that extends radially and possibly axially downwardly through the bottom annular portion  318 ′ similar to pedestal  300  as previously described earlier herein. It is to be understood that the pedestal  300  may be substituted for the bottom pedestal  300 ′ shown in  FIG. 8  in some embodiments. 
     For example in  FIGS. 1, 2 and 3 , it is to be understood that the canister  104  may comprise an outer annular wall  124  that defines an outer diameter  126  that is greater than the bottom diameter of the bottom pedestal  300 ′ (shown in  FIG. 8 ). A support wall  346  would support the bottom annular portion  318 ′ of the bottom pedestal  300 ′, and an arcuate wall  130  would connect the support wall  346  to the outer annular wall  124 . 
     As best seen in  FIGS. 2 and 3 , the filter seal  120  would contact the arcuate wall  130 , forming a drain reservoir  132 . Moreover, the bottom open end  222  of the modified center tube  206  would impinge upon the filter seal  120 , creating a fluid tight seal between center tube  206  and the filter seal  120 , and another fluid tight seal between the filter seal  120  and the arcuate wall  130 . The arcuate wall may have another shape such as conical, etc. The filter seal may be omitted in some embodiments such as when the canister has a bottom closed end, etc. 
     Referring back to  FIG. 8 , the center tube  206 ′ includes a bottom locking slot  224 ′ that extends axially from the bottom open end  222 ′ of the center tube  206  an axial distance  226 ′, and then extends circumferentially a circumferential distance  228 ′. The center tube  206 ′ may also have a top locking slot  224 ″ that extends axially from the top open end  220 ′ of the center tube  206 ′ another axial distance  226 ″, and then extends circumferentially in the opposite direction as compared to the bottom locking slot  224 ′. 
     Furthermore, the center tube  206 ′ may define an inner diameter (not clearly shown but understood to be similar to what has been previously described for pedestal  300  or what is shown in  FIG. 1 ) that is slightly greater than the top diameter of the bottom pedestal  300 ′ that is disposed within the inner diameter of the center tube  206 ′. The bottom tab  322 ′ of the bottom pedestal  300 ′ is disposed in the bottom locking slot  224 ′ and is configured to guide the movement of the center tube  206 ′. Also, the top pedestal  300  may define a diameter (e.g.  316 ) that is slightly less than the inner diameter of the center tube  206 ′, and that is disposed within the inner diameter of the center tube  206 ′. The top tab  322  of the top pedestal  300  may be differently configured than the bottom tab  322 ′ of the bottom pedestal  300 ′, and the top tab  322  may be disposed in the top locking slot  224 ″ to guide the movement of the base. 
     With continued reference to  FIG. 8 , a filter element with a center tube  206 ′ having both top and bottom locking features that may be used with the filter canister system just described will now be discussed. It is to be understood that the center tube  206 ′ shown in  FIG. 8  is simplified to show the use of top and bottom locking features simultaneously. In actuality, the middle portion of the center tube  206 ′ would have perforations similar to what is shown in  FIG. 7 . 
     As alluded to earlier herein, the center tube  206 ′ may have a bottom open end  222 ′ that is joined to the center tube  206 ′ opposite the top open end  220 ′, both of which are disposed along the longitudinal axis  306 ′. The bottom open end  222 ′ may define a radially outer surface  232 ′, and a radially inner surface that is in communication with the central reservoir (not clearly shown in  FIG. 8 ). 
     A first locking feature  236 ′ may be disposed proximate to the bottom open end  222 ′. The first locking feature  236 ′ may include a first entrance slot  238 ′ that is disposed on the radially inner surface (not clearly shown in  FIG. 8 ) of the center tube  206 ′ extending axially upwardly from the bottom open end  222 ′. A first ramp slot  240 ′ may extend axially upwardly and circumferentially counterclockwise from the first entrance slot  238 ′ along a first predetermined direction  241 ′, the first ramp slot  240 ′ being in communication with the first entrance slot  238 ′. The entry slot may be axially tapered to provide a lead-in during assembly. 
     Similarly, a second locking feature  236 ″ may be disposed proximate to the top open end  220 ′. The second locking feature  236 ″ may include a second entrance slot  238 ″ that is disposed on the radially inner surface (not clearly shown in  FIG. 8 ) of the center tube  206 ′ extending axially downwardly from the top open end  220 ′. A second ramp slot  240 ″ may extend axially downwardly and circumferentially clockwise from the second entrance slot  238 ″ along a second predetermined direction  241 ″, the second ramp slot  240 ″ being in communication with the second entrance slot  238 ″. 
     As shown in  FIG. 8 , the first predetermined direction  241 ′ and the second predetermined direction  241 ″ are parallel to each other. For example, this may be true when the first locking feature  236 ′ is identically configured as the second locking feature  236 ″ when rotated about an axis that is perpendicular to the longitudinal axis  306 ′ an amount of 180 degrees, and then aligned axially and circumferentially with the second locking feature  236 ″. This may not be the case for other embodiments of the present disclosure. 
     The first locking feature may further comprise a first circumferential locking slot  242 ′ extending circumferentially counterclockwise from the first ramp slot  240 ′, the first circumferential locking slot  242 ′ being in communication with the first ramp slot  240 ′ and terminating at a first sloping surface  254  that extends axially upwardly and circumferentially counterclockwise. 
     Similarly, the second locking feature  236 ″ may further comprise a second circumferential locking slot  242 ″ extending circumferentially clockwise from the second ramp slot  240 ″, the second circumferential locking slot  242 ″ being in communication with the second ramp slot  240 ″, and terminating at a second sloping surface  254 ′ extending axially downwardly and circumferentially clockwise. 
     For the first locking feature  236 ′, a first detent notch  246 ′ may extend axially upwardly from the first circumferential locking slot  242 ′ being in communication therewith. Likewise for the second locking feature  236 ″, a second detent notch  246 ″ may extend axially downwardly from the second circumferential locking slot  242 ″ being in communication therewith. 
     The first detent notch  246 ′ may terminate circumferentially at a first stop surface  244 ′ that extends axially upwardly from the first sloping surface  254 , and the second detent notch  246 ″ may terminate circumferentially at a second stop surface  244 ″ that extends axially downwardly from the second sloping surface  254 ′. 
     Looking at  FIG. 8 , the center tube  206 ′ has a necked down configuration at the bottom open end  222 ′ including an enlarged bottom annular portion  248 ′, a reduced top annular portion  250 ′, and a transitional annular portion  252 ′ therebetween. The entrance slot  238 ′ is formed by the enlarged bottom annular portion  248 ′, the transitional annular portion  252 ′, and the reduced top annular portion  250 ′. The first ramp slot  240 ′ is formed by the reduced top annular portion  250 ′. The first circumferential locking slot  242 ′, and the first detent notch  246 ′ are formed by the reduced top annular portion  250 ′. The top open end  220 ′ have be similarly described, being mirrored about an axial midplane of the center tube  206 ′. 
     Referring to  FIGS. 5 and 8 , a pair of pedestals  300 ,  300 ′ that may be used with the filter element just described will be discussed in further detail. 
     Each of the pair of pedestals  300 ,  300 ′ may comprise an at least partially annular body  300 ,  302 ′ defining a longitudinal axis  306 ,  306 , a radial direction  308 ,  308 ′, and a circumferential direction  310 ,  310 ′. 
     Each may have a top annular portion  312 ,  312  terminating at a top free end  314 , and a tab  322 ,  322 ′ extending radially from the top annular portion  312 ,  312 ′. The tab  322 ,  322 ′ may include a first axial surface  328 ,  328 ′, a bottom circumferential surface  330 ,  330 ′, and a bottom ramp surface  332 ,  332 ′ extending from the bottom circumferential surface  330 ,  330 ′. As best seen in  FIG. 8 , the surface of one tab may be differently configured (e.g. have different dimensions) than the corresponding surface of the other tab but not necessarily so. 
     Still looking at  FIGS. 5 and 8 , each tab  322 ,  322 ′ may further comprise a top ramp surface  334 ,  334 ′ extending from the first axial surface  328 ,  328 ′ that is parallel to the bottom ramp surface  332 ,  332 ′, a top circumferential surface  336 ,  336 ′ extending from the top ramp surface  334 ,  334 ′, and a second axial surface  338 ,  338 ′ connecting the bottom ramp surface  332 ,  332 ′ to the top circumferential surface  336 ,  336 ′. 
     Each pedestal  300 ,  300 ′ may further comprise a bottom annular portion  318 ,  318 ′ that defines a bottom diameter  320 , and the top annular portion  312 ,  312 ′ defines a top diameter  316  that is less than the bottom diameter  320 . A flared annular portion  324 ,  324 ′ may connect the top annular portion  312 ,  312 ′ to the bottom annular portion  320 ,  320 ′. 
     All of these various surfaces of one tab may be differently configured than the corresponding surfaces of the other tab. Hence, the tab of each of the pair of pedestals may be differently configured. 
     As shown in  FIG. 8 , multiple locking features and tabs may be used at both ends of the center tube  206 ′, but not necessarily so. 
     During installation for the embodiment in  FIG. 8 , the base and/or top pedestal is first attached to the center tube of the filter element. The top tab is prevented from entering the upper detent notch due to its dimensions. Then, the base and filter element are attached to the bottom pedestal until the bottom tab is seated in the lower detent notch since the bottom tab is smaller than the top tab. 
     Next, an interface for use with a filter system similar to that described earlier herein will be discussed with reference to  FIGS. 9  thru  11 . 
     The interface  400  may comprise a filter element  200  that is configured the same as or similar to that as previously described herein. The filter element  200  may include a first open end  402  defining a first locking slot  404 , and a second open end  406  defining a second locking slot  408 . A first pedestal  410  may be provided that includes a first tab  412  that is disposed in the first locking slot  404 . Similarly, a second pedestal  414  may be provided including a second tab  416  that is disposed in the second locking slot  408 . The second tab  416  may be differently configured as the first tab  412 . Either tab may have any suitable configuration including rectangular, square, elliptical, circular, quadrilateral, etc. 
     In some embodiments, the first locking slot  404  may be identically configured as the second locking slot  408  when rotating the geometry of the first slot about an axis that is perpendicular to the longitudinal axis  216  of the filter element  200  an amount of 180 degrees and then aligning the first locking slot  404  with the second locking slot  408  axially, circumferentially, and radially. This may not be the case in other embodiments of the present disclosure. 
     As illustrated in  FIGS. 9 and 10 , the first locking slot  404  may include a first detent notch  418  that defines an extremity  420  that is the furthest axially from the first open end  402  of the filter element  200 , and the first tab  412  may be configured to move axially into and out of the first detent notch  418 . 
     As best seen in  FIG. 11 , the second locking slot  408  may include a second detent notch  422  that defines an extremity  420 ′ that is furthest axially from the second open end  406  of the filter element  200 , and the second tab  416  may be configured to be prevented from moving into and out of the second detent notch  422 . 
     To that end,  FIGS. 10 and 11  show that the first tab  412  includes a first bottom circumferential surface  424  defining a first bottom circumferential surface width  426 , and the second tab  416  includes a second bottom circumferential surface  428  defining a second bottom circumferential surface width  430  that is greater than the first bottom circumferential surface width  424 . The difference in these structures along with the necked throat of the entrance of the detent notches, formed by an axial throat surface  432  and a slanted throat surface  434 , allows the first tab to enter the detent notch and not the second tab. 
     Also, the first tab  412  includes a first ramp surface  436  and a second ramp surface  438  that are parallel to each other and that define a first ramp width  440  that measured perpendicularly to the first ramp surface  436 . Likewise, the second tab  416  defines a third ramp surface  442  and a fourth ramp surface  444  that are parallel to each other and that define a second ramp width  446  that is measured perpendicularly to the third ramp surface  442  and the fourth ramp surface  444 . The second ramp width  446  may be greater than the first ramp width  440 , blocking its entry into the detent notch. 
     Accordingly, the first tab  412  may be configured to move axially (into the entrance portion of the first locking slot  404 ), diagonally (along the ramp portion of the first locking slot  404 ), circumferentially (in the circumferential portion of the first locking slot  404 ) and axially into the first detent notch  418 , while the second tab  416  is configured to move axially, diagonally, and circumferentially in like manner as the first tab, except that the second tab  416  reaches a stop  448  (see  FIG. 11 ) in the second locking slot  408  before entering the second detent notch  422 . This may not be the case for other embodiments of the present disclosure. 
     Any of the aforementioned features may be varied in configuration to be different in other embodiments of the present disclosure. In particular, the locking slot may follow any desirable path and may have differently configured walls that form them while the tabs may have any suitable configuration including round, polygonal, etc. 
     INDUSTRIAL APPLICABILITY 
     In practice, a filter element, a pedestal, or a canister filter system according to any embodiment disclosed herein may be obtained or provided in an OEM (original equipment manufacturer) or aftermarket context. The various features previously discussed may be used to both properly orient, position, and lock the various components of the canister filter system into place. 
     The center tube and the pedestal may be made from any suitable material including plastic, metal, etc. It may be desirable to choose materials that are chemically compatible with the fluids being filtered. 
     In previous designs, there may be a problem related to the attachment of the filter element to the housing (canister). Conventionally, the attachment of filter element to the housing, maintaining the proper force on the seal, and providing alignment of the filter element to the housing may be difficult. 
     Various embodiments of the present disclosure allow a newly developed method to install the filter element to the housing. The filter installation helps to ensure the proper alignment of filter element within the housing as well as maintaining the downward force on the seal. Further, the new design of filter element includes slots in the center tube that will allow tabs on the filter housing pedestal to engage. When the filter is rotated, it will provide locking of the filter element with the housing and the required force to help ensure the proper engagement of the seal with the housing base for the separation of pure and impure water, etc. Moreover, the slots and pedestal tabs can be changed (in number, position, configuration, etc.) so that wrong filter is not used resulting in damage to machine components. 
     More specifically, the tab of the lower pedestal engages the corresponding locking slot of the center tube, providing downward force to push bottom seal into place when the filter is rotated into housing at installation. Also, the position of the top seal is also provided so that it will seal properly. 
     It is contemplated that other embodiments of the present disclosure may work or be structured differently so not all of the benefits just described may be obtained. 
     In some embodiments, the filter element/center tube may sit on top of the tab(s) at the bottom of the housing. In such a case, a proper seal may be provided at the top end, but the user may have to provide the force to overcome the seal at the bottom, etc. 
     It is further contemplated that the features of the pedestal including the tab may be swapped for the features of the center tube/filter element including the locking feature/slot, etc. in other embodiments of the present disclosure. 
     In light of the foregoing, a method of assembly of a canister filter system according to an embodiment of the present application may be employed as depicted in  FIG. 12 . 
     The method  500  may comprise inserting a first filter component into a second filter component (step  502 ), and continuing the insertion until a first tab of either the first filter component or the second filter component contacts the other of the first filter component and the second filter component (step  504 ). For example, the filter element may be inserted into a filter base or a canister (housing), etc. until the filter element contacts the tab of the filter base or canister (or vice versa). 
     In particular embodiments, the first tab of either the first filter component or the second filter component slides into a first slot of the other of the first filter component or the second filter component (step  506 ). 
     Sometimes, the first tab slides upwardly in the first slot until the first tab reaches a ramp portion of the first slot (step  508 , e.g. see  FIGS. 2  thru  4 ,  8 ). 
     Then, the first filter component or the second filter component may be rotated, causing the first tab to slide along the ramp portion of the first slot until the first tab reaches a circumferential portion of the first slot, causing the first filter component or the second filter component to contact a seal (step  510 , e.g. see  FIGS. 2  thru  4 ). 
     Next, the first filter component or the second filter component (or both) may be rotated until the first tab reaches a stop or a detent notch (step  512 , e.g. see  FIGS. 4, 10, and 12 ). 
     In some embodiments, the first tab slides upwardly or downwardly in the detent notch (step  514 , e.g. see  FIGS. 4, 8, and 10 ). 
     In yet further embodiments, the method  500  may further comprising attaching the first filter component or the second filter component to a third filter component, providing a seal (step  516 , e.g. see  FIG. 1  which indicates the canister and the filter element may be attached to the base to create one or more seals). 
     The method  500  may also include inserting a second tab of a third filter component into a second slot of the first filter component or the second filter component until the second tab reaches a ramp portion of the second slot (step  518 , e.g. see  FIGS. 1, 8  thru  11 ). 
     In such a case, the method  500  may further comprising rotating the first filter component or the second filter component until the second tab slides along the ramp portion of the second slot, reaches a circumferential portion of the second slot, and continues until the second tab reaches a second stop or a second detent notch (step  520 ). 
     If a second detent notch is reached, then the second tab may slide upwardly or downwardly in the second detent notch (step  522 ). 
     Once assembled as best seen in  FIG. 1  for some embodiments of the present disclosure, a bottom seal  140 , an inner top seal  142 , and an outer top seal  144  may be created to help prevent any fluid from leaking. 
     It will be appreciated that the foregoing description provides examples of the disclosed assembly and technique. However, it is contemplated that other implementations of the disclosure may differ in detail from the foregoing examples. All references to the disclosure or examples thereof are intended to reference the particular example being discussed at that point and are not intended to imply any limitation as to the scope of the disclosure more generally. All language of distinction and disparagement with respect to certain features is intended to indicate a lack of preference for those features, but not to exclude such from the scope of the disclosure entirely unless otherwise indicated. 
     Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments of the apparatus and methods of assembly as discussed herein without departing from the scope or spirit of the invention(s). Other embodiments of this disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the various embodiments disclosed herein. For example, some of the equipment may be constructed and function differently than what has been described herein and certain steps of any method may be omitted, performed in an order that is different than what has been specifically mentioned or in some cases performed simultaneously or in sub-steps. Furthermore, variations or modifications to certain aspects or features of various embodiments may be made to create further embodiments and features and aspects of various embodiments may be added to or substituted for other features or aspects of other embodiments in order to provide still further embodiments. 
     Accordingly, this disclosure includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the disclosure unless otherwise indicated herein or otherwise clearly contradicted by context.