Patent Description:
Installation and removal of filters often require them to be threaded onto a stud in a base or casting. Many filters such as canister type filters have a permanent housing and are entirely disposable at filter change intervals. If the filter is partly reusable, a lid is typically threaded to a housing enclosing a filter element, which can be removed and replaced. Threading a filter to a base or lid to a housing typically requires tools and time to service, which can keep a piece of equipment out of operation.

A variety of filter retention systems are known generally such as reflected in <CIT> entitled Fuel Filter Retention system; <CIT> entitled Filter Assembly; <CIT> entitled "Fuel Filter Assembly and Cartridge"; <CIT> entitled "Eccentric interference retention system for a filter cartridge"; <CIT> entitled "Filter element and filter assembly including locking mechanism"; <CIT> entitled "Filter with improved fatigue performance and torque transfer"; <CIT> entitled "Hydraulic spin-on filter cartridge having base plate supporting radially directed seal"; <CIT>, entitled "Sealing for liquid filter"; <CIT> entitled "Filter"; and <CIT> entitled "Housing for environmentally friendly filter cartridge".

To improve installation and removal, designs have been developed that utilize collars, such as shown in <CIT> to keep the filter attached to the base; or twist lock designs such as shown in <CIT> or U.

Patent <CIT>. These designs are limited in pressure capability and traditionally used for lower pressure fuel applications.

In addition, collars used to attach filters to a base can become lost if the collar is not permanently attached to the base. This can become problematic when servicing in the field if another collar is not available. Equipment downtime can result.

Higher pressure applications such as hydraulic filters can experience high normal operating pressures well in excess of <NUM> PSI and in some instances in excess of <NUM>,<NUM> PSI as described <CIT>, entitled "Sealing for liquid filter". As shown therein and in <CIT>; <CIT><CIT> also disclose such hydraulic filters use spin-on connections between a hydraulic filter and base that utilizes a threaded stud to attach the filter to the base.

Similar threaded stud mounting configuration exists for traditional spin-on lube filters, as shown in <CIT> entitled "Filter". Also, <CIT> is an example of a cartridge filter that fits inside a housing with a screw-on lid.

The following documents may also provide technical background to the present disclosure: <CIT>; <CIT>; <CIT>; and <CIT>.

In accordance with an inventive aspect, a filter is provided with several radial projections of a baseplate, which provide a non-threaded connection.

At least one radial projection projects radially from the mouth between the filter housing and a distal end of the mouth. In particular, the present invention provides a filter as defined in appended claim <NUM>. Optional features are defined in the appended dependent claims.

Several features and additional structures may be employed with a filter either alone and/or in combination as in the below different paragraphs.

The filter may further comprise a ring seal supported within a first annular channel defined by the mouth toward a distal end of the mouth.

Preferably the baseplate and the filter housing are separate component parts, the baseplate including the annular mouth and the at least one radial projection are at least one of a machined structure and a casting from at least one of steel or aluminum, and wherein the filter is a liquid filter.

The at least one projection serves as a mounting base retainer providing a strength property such that the mounting base retainer can provide an axial retaining force when the filter is subjected to a pressure greater than <NUM> PSI.

For example, at least <NUM> of the radial projections and at least <NUM> of the radial gaps can be provided, with the radial projections and the radial gaps being matched of substantially similar geometric size and configuration.

The annular mouth may be stepped to include a thicker diameter region from which the one or more radial projections extend and a thinner diameter region along distal tip region above the one or more radial projections.

The baseplate may also provide an annular receiving groove region is arranged below the at least one projection and axially between the at least one projection and the filter housing that is sized and configured for receiving mounting protrusions from a filter head.

The baseplate can further comprise a step in outer diameter from a terminating cylindrical portion extending axially away from the at least one radial projection to a terminating end, and an intermediate cylindrical portion supporting the at least one radial projection.

The filter element may comprise a tubular ring of the filter media, an open end cap and a closed end cap. The open end cap is bonded to the tubular ring of the filter media proximate the open end and the closed end cap is bonded to the tubular ring of the filter media proximate the closed end.

In such a filter element, a spring can engage between the closed end and the closed end cap urging the filter element against the baseplate.

For example to receive the filter element, the baseplate can further comprise an annular hub including a tubular extension, with the annular hub connected to the annular mouth by a plurality of ribs to define the inlet port. The outlet port can be defined within the tubular extension which provides an annular divider between the inlet portion and the outlet port. Preferably, the tubular extension having groove carrying a ring seal for sealing purposes.

For the filter element, open end cap may also comprise an annular disc portion and a tubular extension projecting therefrom to provide the outlet port therein and serve an annular divider to define the inlet port between the open end cap and the baseplate.

In an example, the filter housing comprises a cylindrical metal canister having a terminating lip edge bent over the baseplate directly connected the filter housing and the baseplate.

In such example, the baseplate can further include an outermost annular wall and an annular ledge, with the outermost annular wall depending and axially extending from the ledge, with the ledge extending radially inward from the outermost annular wall to the annular mouth, and with the terminating lip edge engaging over the annular ledge. Preferably, a ring gasket seals between the baseplate and the outermost annular wall.

When a baseplate is directly connected to the housing (but not in a unitary manner), an annular bead provides a neck (and/or another form of neck is provided for example by a stepped canister), which is formed into the cylindrical metal canister and engages a terminating end of the outermost annular wall to sandwich and permanently secure the baseplate between the terminating lip edge and annular bead or neck.

Preferably, the filter housing is permanently mounted to the baseplate, and the filter element is one of removable and permanently installed in the filter housing.

The filter element can further comprise an open end cap and a closed end cap, wither the open end cap bonded to the filter media proximate the open end and the closed end cap bonded to the filter media proximate the closed end, with the baseplate being non-unitary as a separate structure from the open end cap.

Another aspect is directed toward a filter and base assembly that includes such a filter. The assembly also comprises a filter base including a unfiltered fluid outlet, and a filtered fluid inlet with the filter removably connected to the filter base. A collar retains the filter to the filter base, with the collar including a plurality of protrusions interlocking with the filter and axially engaging against the at least one radial projection to retain the filter to the filter base.

Referring to <FIG> and <FIG>, an embodiment of the present invention has been illustrated as a filter and base assembly <NUM> for filtering fluid (e.g. oil, hydraulic working fluid, other liquids, etc.). The assembly <NUM> comprises a filter base <NUM> and a filter <NUM>, along with a collar <NUM> that can removably connect and secure the filter <NUM> to the base <NUM>.

The embodiments illustrated herein are particularly applicable to high pressure applications that may experience pressures exceeding <NUM> PSI. As such the mounting interface parts between the collar and the filter are preferably composed of metal such as steel or aluminum, which provides high strength and low deflection.

The filter base <NUM> includes an unfiltered fluid outlet <NUM>, and a filtered fluid inlet <NUM>. For example, the filter base <NUM> is mountable to an engine, working hydraulic fluid circuit or other fluid filtration application. The filter base <NUM> can receive unfiltered fluid, and transmit unfiltered fluid to the filter <NUM> through the unfiltered fluid outlet <NUM>. The filter base <NUM> can receive filtered fluid back from the filter <NUM> though the filtered fluid inlet <NUM>, which the filter base can transmit back filtered fluid then to the given application for use (e.g. lubrication and/or hydraulic working cylinders, actuators, etc.).

The filter <NUM> comprises a housing <NUM> containing a filter media <NUM>, and a mounting interface <NUM> adjacent an end of the housing. The mounting interface <NUM> includes an inlet port <NUM>, an outlet port <NUM> and a plurality of radial projections <NUM>. The mounting interface <NUM> provides both fluid communication as well as removable mechanical connection with the filter base <NUM>.

For example, as illustrated, the mounting interface <NUM> is in fluid communication with the filter base with the unfiltered fluid outlet <NUM> communicating with the inlet port <NUM> for conveying unfiltered fluid to the filter <NUM>, and the outlet port <NUM> communicating with filtered fluid inlet <NUM> for conveying filtered fluid back to the filter base <NUM>. Schematic flow path arrows indicate a fluid passageway <NUM> from the inlet port through the filter media to the outlet port for filtering fluid.

The collar <NUM> is rotatably mounted on the filter base and serves to releasably retain the filter <NUM> to the filter base <NUM>. The collar <NUM> includes a plurality of protrusions <NUM> interlocking with the filter <NUM> by axially engaging against the radial projections <NUM> to retain the filter to the filter base.

The radial projections <NUM> enable the filter and its mounting interface <NUM> to be free of conventional threading used in several other traditional filter applications as noted in the background.

For example, as shown in <FIG>, adjacent radial projections <NUM> define cut-out regions that provide gaps <NUM> therebetween that align and are configured in size to receive the protrusion <NUM> axially therethrough. Similarly, adjacent protrusions <NUM> define cut-out regions that define receiving slots <NUM> that allow the radial projections <NUM> to pass therethrough.

Once the protrusions <NUM> pass through the gaps <NUM> and the projections <NUM> pass through the slots <NUM> with the filter being pushed onto the base (i.e. the unlocked state), the collar <NUM> can be rotated which aligns the protrusions <NUM> over the projections <NUM> thereby axially retaining the filter <NUM> to the filter base <NUM> (i.e. the locked state). The unlocked state is shown in <FIG>, <FIG> as well as <FIG> allowing axial displacement between the filter <NUM> and the filter base <NUM>, whereas in <FIG> the collar has been rotated to thereby axially retain the filter to the base by interlocking engagement between the protrusions and the projections.

To provide for fluid connections, the mounting interface <NUM> comprises an annular mouth <NUM> that may be provide by an outer cylindrical wall portion and an annular divider <NUM> that may be provided by an inner cylindrical wall portion. As show, the annular divider <NUM> is concentric within the annular mouth <NUM>.

To interact and seal with the annular mouth <NUM> and the annular divider <NUM> of the mounting interface, the filter base <NUM> includes complimentary structures. For example, the filter base <NUM> further comprises an outer annular wall <NUM> that received the distal tip end of the annular mouth <NUM>. Further, the filter base includes an inner annular wall <NUM> which receives the distal tip end of the annular divider <NUM>.

For the filter base <NUM>, the inner annular wall <NUM> defines the filtered fluid inlet <NUM>. The outer annular wall <NUM> surrounds the inner annular wall <NUM> to define the unfiltered fluid outlet <NUM> radially therebetween.

To provide for a sealed connection when the filter <NUM> is mounted to the base, the filter <NUM> further comprises a first seal such as an O-ring gasket <NUM> supported within a first channel <NUM> circumscribing the annular mouth <NUM> toward a distal end of the annular mouth <NUM>. The O-ring gasket <NUM> seats and seals against the annular mouth <NUM> and also against the outer annular wall <NUM> to seal the inlet flow path between the unfiltered fluid outlet <NUM> and the inlet port <NUM>.

The filter <NUM> also comprises a second seal such as an O-ring gasket <NUM> supported within a second channel <NUM> circumscribing the annular divider <NUM> toward a distal end of the divider. The O-ring gasket <NUM> seats and seals against the annular divider <NUM> and also seals against the inner annular wall <NUM> to seal the outlet flow path between the outlet port <NUM> and the filtered fluid inlet <NUM>.

The outer annular wall <NUM> also provides a support structure for the collar <NUM>. For example, the collar <NUM> as shown is retained and rotatable on an outer periphery of the outer annular wall <NUM>. The outer annular wall <NUM> and the collar <NUM> include a retainer flange <NUM> and a retainer groove <NUM>, respectively or vice versa.

In this case, the retainer flange <NUM> is on the filter base <NUM> and the retainer groove <NUM> is formed into the inner periphery of the collar <NUM>. In the present embodiment, the retainer flange <NUM> projects radially outwardly from the outer annular wall <NUM> and the retainer groove <NUM> is formed radially into an inner periphery of the collar <NUM>.

The retainer flange <NUM> can comprise a plurality of flange segments 400A that project axially and radially from the outer annular wall <NUM> of the base as shown in <FIG> such that the flange segments 400A can interfit and key with the radial projections of filter <NUM>. The flange segments 400A are received within the groove <NUM> of the collar (see <FIG>), which groove <NUM> provides a step 500A (see detail in <FIG>) that defines a radially inward flange that axially supports loads exerted upon the collar <NUM> during pressurization of the filter <NUM>.

Another retainer flange and retainer groove are provided with rotation stop groove <NUM> and rotation flange <NUM>. Although these can axially retain, primarily these retain in a rotational direction.

The rotation stop groove <NUM> receives the rotation flange <NUM> to align the collar <NUM> to the filter base <NUM>. The flange and groove may extend all of the way around (<NUM> degrees) the base and the collar. Or alternatively such as shown in <FIG> and <FIG>, the rotation stop flange <NUM> may be provided by flange segments 48A and the rotation stop groove <NUM> may be provided by groove segments 50A that extend only a limited angular span. Although as noted above the locations may be reversed with the rotation stop groove on the base and the rotation stop flange on the collar.

Further, as will also be seen with reference to <FIG> and <FIG>, the rotation stop groove such as provided by groove segments 50A are long enough to allow sliding movement of the rotation stop flange as provided by flange segments 48A therein. This allows rotation of the collar <NUM> between the locked state in which the protrusions are aligned with the radial projections to retain the filter to the filter base and the unlocked state in which the protrusions align with the gaps between adjacent radial projections to allow the filter to be moved axially relative to the filter base.

Preferably the ends of the rotation stop groove segments 50A define stops that will engage with the rotation flange segments 48A to limit rotational travel movement of the collar corresponding to locked and unlocked states to either align the protrusions <NUM> with the radial projections <NUM> for locking the filter to the filter base, or align the radial projections with the slots <NUM> between protrusions (e.g. see <FIG>) in the unlocked state to allow for filter removal or installation by moving the filter <NUM> axially relative to the filter base <NUM>.

To facilitate assembly and keep the collar <NUM> attached to the filter base <NUM> in a permanent manner (e.g. without tool removal), the collar <NUM> may be split into collar segments <NUM>, which in this case are two collar segments although three or more collar segments may be provided in additional embodiments. As shown in <FIG>, the collar segments <NUM> are assembled in place upon the filter base to accommodate interfitting of the retainer groove <NUM> and the retainer flange <NUM> as well as the groove <NUM> and flange <NUM>.

The collar segments <NUM> are connected in place over the outer annular wall <NUM> of the filter base <NUM> with segment ends connected to each other by connectors.

For example, as shown in <FIG>, the collar segments <NUM> include stepped regions <NUM> at first and second ends that overlap and are connected to each other.

To facilitate assembly, the stepped regions <NUM> may include holes <NUM> that overlap and align in order to provide: first pinned connection or hinge <NUM> at a first segment end allowing pivoting movement between segments; and a second pinned connection <NUM> to connect the free ends shown in <FIG>. To attach ends of collar segments <NUM> together suitable fasteners such as pins <NUM> (e.g. such as a rivet or press fit pin or screws/bolts) may be fitted and fastened into the aligned holes <NUM> of the collar segments <NUM>.

While the filter has been described in some detail above, additional attention will now be afforded to the filter <NUM>. There are two illustrated embodiments for the filter, one in which the mounting interface is provided by a single component part shown in <FIG>; and more preferably where the mounting interface is provided by two or more component parts as shown in <FIG>. As these embodiments are otherwise the same other than configuration of baseplate and/or end cap at the open end, the same reference numbers will generally be used among these embodiments other than as applied for the differences between parts.

Referring to <FIG> (and with additional reference to other figures), the filter includes an internal filter element <NUM> housed within the housing <NUM>. The filter element <NUM> incorporates the filter media <NUM> previous described that may take the form of a tubular pleated ring <NUM> of filter media sheet, which may be supported upon a tubular perforated support core <NUM>.

To facilitate assembly, the filter housing <NUM> has an open end <NUM>, a closed end <NUM> and a sidewall <NUM> extending between the open end <NUM> and the closed end <NUM>. The sidewall <NUM> is disposed around the filter element <NUM> in spaced relation to facilitate the fluid flow passageway <NUM>. As shown, the flow passageway <NUM> extends from the inlet port <NUM>, internally through the baseplate to an annular chamber between the filter housing <NUM> and the pleated ring <NUM>. In operation, fluid pressure then pushes unfiltered fluid through the pleated ring <NUM> so that particulates are filtered out by the filter media and the flow passageway <NUM> passes internally into a central filtered cavity inside the pleated ring <NUM> that is connected directly to the outlet port <NUM> to complete the flow passageway for returning filtered fluid to the filter base.

To provide for at least part of the mounting interface and at least the annular mouth <NUM>, the filter <NUM> includes a baseplate <NUM> connected to the filter housing <NUM> at the open end <NUM>. The baseplate <NUM> provides the annular mouth <NUM>. In this and the other illustrated embodiment, the inlet port <NUM> and the outlet port <NUM> are radially inside of the annular mouth <NUM>.

Further the baseplate <NUM> provides for the various radial projections <NUM> projecting radially from the mouth <NUM> in a region between the filter housing and a distal end of the mouth.

Preferably and especially for higher pressure applications such as hydraulic filters, the baseplate <NUM> including the annular mouth <NUM> along with the radial projections <NUM> are either a machined structure or a casting, and in either case being made from at least one of steel or aluminum. For example, this can provide a hydraulic filter.

For such high pressure applications such as hydraulic fluid filtration (and referring again to the overall assembly <NUM>), preferably the collar <NUM> and filter base <NUM> both are either a machined structure or a casting, and in either case being made from at least one of steel or aluminum. The materials and forms can provide and withstand high pressure loads and keep the filter fastened and sealed to the filter base.

Accordingly, the high strength baseplate <NUM> along with the radial projections <NUM> can serve as a mounting base retainer providing a strength property such that the mounting base retainer can provide an axial retaining force when the filter is subjected to a pressure greater than <NUM> PSI.

While one projection may be possible, preferable the baseplate <NUM> provides plurality of the radial projections <NUM> in spaced relation with the radial gaps <NUM> defined between adjacent projections around the mouth <NUM>. As shown, the radial projections project radially outwardly away from the mouth <NUM>. While two larger radial projections are contemplated, more preferably for balancing higher pressure, at least <NUM> of the radial projections at least <NUM> of the radial gaps are provided.

As shown, the radial projections <NUM> and the radial gaps <NUM> are matched of substantially similar geometric size and configuration (and similarly the protrusions <NUM> are substantially similar geometric size and configuration). In this manner surface to surface contact can be maximized, and also balance and a special angular mounting orientation is not required. By matched of substantially similar geometric size and configuration, it is meant that the sizes in terms of area occupied are within <NUM>% of each other, with the gaps maybe slightly larger to allow for install and removal clearance.

To also provide strength, it can be seen that the annular mouth <NUM> may be stepped to include a thicker diameter region <NUM> (which may constitute an intermediate cylindrical portion) from which the radial projections <NUM> extend and a thinner diameter region along distal tip region <NUM> (which may constitute a terminating cylindrical portion) above the radial projections <NUM>, which may be utilized to support the O-ring <NUM> for sealing.

Additionally, along the intermediate cylindrical portion provided by the thicker diameter region, is an annular receiving groove-like region <NUM> arranged below the radial projections <NUM> and axially between the radial projections <NUM> and the filter housing <NUM>. This groove-like region <NUM> is sized and configured for receiving mounting protrusions <NUM> from the filter head.

Referring to <FIG>, the filter element <NUM> comprises a tubular ring of the filter media provided by the pleated ring <NUM> along with an open end cap <NUM> and a closed end cap <NUM>. The open end cap <NUM> is bonded to the pleated ring <NUM> proximate the open end <NUM> of the housing <NUM>. The closed end cap <NUM> is bonded to the pleated ring <NUM> proximate the closed end <NUM> of the housing. To keep the filter element in sealing alignment relation proximate the open end <NUM> (in this case with the filter base when in use), a coil spring <NUM> is compressed and engages between the closed end <NUM> of the housing and the closed end cap <NUM>. The spring <NUM> urges the filter element <NUM> against the baseplate <NUM>.

While open and closed end caps are illustrated, the filter could include an opening on the bottom end cap of the element such as for certain fuel filtration applications. For example, in a coalescing fuel filter the bottom end cap next to the spring could have a seal on the outside diameter and water drop out the bottom of the inner diameter of the element in which the seal on the outside would close the bottom end cap to unfiltered fluid and also serve as a sump for water collection in the closed end of the housing (which closed end may incorporate a drain valve or drain cock for water removal).

In the present embodiment shown in <FIG>, the open end cap <NUM> serves as part of the mounting interface <NUM> by providing the annular divider <NUM> and the outlet port <NUM>. To provide for this, the open end cap <NUM> comprises an annular disc portion <NUM> that bonds to the top end of the pleated ring <NUM> (e.g. directly through embedding or by adhesive attachment with plastisol or other such adhesive), and a tubular extension <NUM> projecting from the disc portion <NUM>. The tubular extension <NUM> thereby provides the outlet port <NUM> therein and serves as the annular divider <NUM> to define the inlet port between the open end cap and the baseplate.

Additionally, ribs <NUM> are disposed between the open end cap <NUM> and the baseplate <NUM> to allow incoming unfiltered fluid to pass into the filter along the fluid flow passageway <NUM> and between the open end cap <NUM> and the baseplate <NUM>. While the ribs <NUM> could be on the baseplate or a separate intermediate structure, preferably the ribs <NUM> as shown in this embodiment are molded directly into the open end cap <NUM>, which may be conveniently a molded plastic structure. The ribs <NUM> can engage and seat within an annular stepped region <NUM> defined on the inner periphery of the baseplate <NUM>. The spring <NUM> axially loads the filter element <NUM> to seat the open end cap <NUM> against the baseplate <NUM>, with the ribs <NUM> seated against the stepped region <NUM>. The inner perforated support core <NUM> may be a metal or plastic tube that in addition to supporting the media radially also can carry axial loads transmitted by the spring <NUM> and prevent collapse of filter media.

Turning to the embodiment <FIG>, the same reference numbers will be used for common and/or substantially similar structures and like reference numbers (same number plus one hundred) will be used for similar elements or portions as in the first illustrated embodiment, with the difference between the configuration of the baseplate <NUM> and the open end cap <NUM> as shown in the embodiment of <FIG>.

In comparing the first embodiment of <FIG> with that of <FIG>, it can be seen that the difference is that in the first embodiment, the upper end cap <NUM> of the filter element <NUM> provides the outlet port and part of the mounting interface <NUM>, whereas in the second illustrated embodiment of <FIG>, the baseplate <NUM> itself provides the entire mounting interface <NUM> by providing both the annular mouth <NUM> and the annular divider <NUM>.

In <FIG>, the baseplate <NUM> is a single unitary structure with a central annular hub <NUM> that includes a tubular extension providing the annular divider <NUM>. The annular hub <NUM> is unitarily connected to the annular mouth <NUM> by a plurality of ribs <NUM> to define the inlet port <NUM>, with the outlet port <NUM> defined within the tubular extension provide by the annular hub <NUM> and thereby providing the annular divider <NUM> between the inlet port and the outlet port. Similar to the first embodiment, the tubular extension of the annular hub <NUM> also has channel <NUM> carrying an O-ring seal <NUM> for sealing the return flow path to the filter base <NUM>.

The open end cap <NUM> in this embodiment is not a molded plastic end cap as in the earlier embodiment, but can be a cup shaped cap (e.g. stamped metal end cap) that has a potting well for bonding to the top end of the pleated ring <NUM> such as with plastisol or other similar adhesive. This is similar to the bottom closed end cap <NUM> that can be the same as in the earlier embodiment as a metal cup shaped member bonded with plastisol or other similar adhesive agent. This provides the embodiment of <FIG> with a more conventional type of internal filter element <NUM>.

To prevent bypass of unfiltered fluid past the annular divider <NUM>, a seal such as and O-ring gasket <NUM> seals between the open end cap <NUM> and the baseplate <NUM>. The open end cap <NUM> includes a seating step <NUM> along its inner periphery that holds and seals against one side of the gasket <NUM>, and similarly the baseplate defines a seating step <NUM> along the annular hub <NUM> on the axial and radial inner periphery that receives seals against one side of the gasket <NUM>. Thus, the gasket <NUM> can be squeezed by application of axial force by the spring <NUM>.

Accordingly, other than the differently configured baseplate <NUM> and the open end cap <NUM> configuration for <FIG>, the description of that for the first embodiment of <FIG> is applicable thereto and vice versa.

Returning again to <FIG> and with reference to <FIG>, the baseplate <NUM> is preferably configured for a permanent housing type application suitable for hydraulic filtration (or oil filtration or other liquid filtration). In the present embodiment, the housing <NUM> takes the form of a deep drawn sheet metal canister <NUM> to provide a strong structure to resist high pressures and provide the open end <NUM>, the closed end <NUM> and the sidewall <NUM> in a single unitary component part. The canister <NUM> can be cylindrical and can unitarily include a terminating lip edge <NUM> bent over the baseplate <NUM> to directly connect the filter housing <NUM> and the baseplate <NUM>.

To support the lip edge <NUM> and provide for a rigid permanent connection, the baseplate <NUM> further includes an annular wall that may be offset from the annular mouth <NUM> connected to the annular mouth by a neck region that provides an annular ledge <NUM> for receiving the bent terminating lip edge <NUM> to provide a rigid connection.

For example, the annular ledge <NUM> can extend radially outward from the annular mouth <NUM> from which then depends an outermost annular wall <NUM>. Thus the annular ledge <NUM> extends radially inward from the outermost annular wall <NUM> to provide a region to receive a bent end portion of the canister (i.e. terminating lip edge <NUM>) at the open end. The outermost annular wall <NUM> has a cylindrical outer periphery closely receiving the cylindrical inner periphery of the canister <NUM>. A ring gasket <NUM> seals between the baseplate <NUM> and the outermost annular wall <NUM> and can be situated in a radially outward facing annular groove <NUM> made into the baseplate <NUM>.

To provide a region to receive the bent terminating lip edge <NUM>, an annular receiving clearance groove region <NUM> is formed along the exterior top side of the ledge <NUM> which may merge into the outer cylindrical peripheral surface of the outermost wall <NUM> at an acute angle to provide a pointed corner <NUM> that focuses axial retention force with the canister for secure permanent connection.

Further, the canister <NUM> can have formed therein an annular bead <NUM> that engages a bottom (e.g. axially innermost) terminating end of the outermost annular wall <NUM> to sandwich and permanently secure the baseplate <NUM> between the canister's terminating lip edge <NUM> and annular bead <NUM>. The annular bead thereby provides a neck, which also could be provided by a reduced diameter portion of the canister.

Although not necessitated as a threaded attachment to the filter base is not used, cutout portions <NUM> in the baseplate may also receive portions of the annular bead <NUM> and can also provide torque transfer means to prevent relative rotation between the canister and the baseplate.

While a permanent connection is shown and preferred such as for high pressure applications such as hydraulic filters, optionally the housing <NUM> could be reusable, for example be configured similar to how is done in <CIT>which has a split housing with a housing base and a closed end in the form of a screw-on lid, which can optionally be provided as schematically indicated by lines <NUM> in <FIG>. In such a resusable housing embodiment, the housing may be plastic or other materials besides metal, particularly if for lower pressure application. The baseplate likewise can then be reusable. However even in such a reusable housing embodiment the housing is considered part of the filter and the baseplate has a thread-free mounting interface connection to the filter head.

While it is believed especially in higher pressure applications that further locking means may not be needed, optionally additional collar locking can be provided by a detent mechanism <NUM> a part of which is shown in <FIG>, but can be much better in <FIG>. Referring therefore to <FIG>, the detent mechanism <NUM> acts between the collar <NUM> and the filter base <NUM> in at least the locked state in which the collar's protrusions are axially aligned with the filter's radial projections to axially retain the filter to the filter base. This locked state is shown in <FIG>.

The detent mechanism <NUM> can be manually deactivated to rotate the collar to an unlocked state in which the collar's protrusions align with gaps between adjacent radial projections of the filter (see also <FIG>) to allow the filter to be moved axially relative to the filter base. In <FIG> it can be seen that the transition is occur from the locked toward the unlocked state that is shown in <FIG>. In this condition, the detent mechanism is not engage but riding on a cylindrical surface defined between detents.

The detent mechanism <NUM> includes a first detent <NUM> (e.g. a catch such as a notched groove) corresponding to and holding the collar in the locked state and may also optionally include a second detent <NUM> (e.g. another catch such as a notched groove) corresponding to and holding the collar in the unlocked state. The first and second detents <NUM>, <NUM> are spaced circumferentially apart by an angular span corresponding to the rotation needed to align the filter's radial projections with either the collar's protrusions or gaps therebetween to allow for retention or install/removal as may be desired.

To engage with one or both detents <NUM>, <NUM> the detent mechanism also comprises an interacting catch, for example such as may be provided by a spring plunger <NUM>. Manual force alone is sufficient to deflect spring plunger to allow rotation, but the spring plunger provides enough force to prevent dislodging of the collar during filtering operation.

For example, spring plunger <NUM> may include a threaded plunger housing <NUM> having a spring cavity supporting a spring <NUM> therein that urges a catch tab such as pin projection <NUM> outwardly away from the housing so as to engage with detents <NUM>, <NUM>. The threaded plunger housing <NUM> is threaded into a threaded hole <NUM>, such as on the collar <NUM>.

In this present embodiment, therefore, the spring plunger <NUM> is mounted on the collar <NUM> and the detents <NUM>, <NUM> formed into the filter base <NUM>, however it is realized the locations of these respective structures could be reversed with the detents on the collar and the spring plunger on the base.

As described above, embodiments may utilize a permanent collar rotatably fixed to a free-standing filter base that may be provided by a casting. The collar has a series of cutouts between wedge-shaped, radially inward extending protrusions on the inner diameter of the collar that accepts projection(s) extending radially outward from a baseplate of filter cartridge. When the collar is twisted, protrusions from the collar moves under the projections on the baseplate to trap the projections between the protrusions and an inner annular ledge within the collar, so as to lock the cartridge to the base or casting. To remove the filter, the collar is twisted in the opposite direction to release the projection(s), and the filter can be pulled out of the collar and apart from the base/casting. This eliminates the need for threads on a filter, normally used in, e.g., medium pressure lube and hydraulic applications.

As shown, an end cap may be fixed at one end of the media ring. The end cap engages with a baseplate having a central circular opening. An annular mouth projects outwardly from the baseplate, coaxial with the central axis. The mouth can include i) a first seal supported within a first channel circumscribing the mouth toward a distal end of the mouth, and ii) one or more radial projections spaced around the circumference of the mouth between the baseplate and seal, and projecting outwardly, away from the mouth.

The projections mate with a similar shaped cutout on the inner diameter of the collar, formed by radial protrusions, (e.g. see <FIG>). Preferably, the collar is permanently rotatably mounted to the filter base. <FIG> shows the baseplate aligned and ready to be inserted into the collar. Once a filter has been inserted into the collar, such as shown in <FIG>, the collar is twisted and the protrusions in the collar support the projections in the baseplate, as shown in <FIG>. The baseplate can have multiple projections extending radially from it but could contain a minimum of one.

The baseplate contains a radial seal supported within a channel and extending outward toward the distal end of the baseplate. The seal could likewise extend inward to seal the baseplate to the filter head. In the preferred design, the projections extend outward from the base, and the cutouts on the baseplate are on the inner diameter; but the projections could likewise extend radially inward from the baseplate, and the cutouts could be provided on the collar extending from the outer diameter.

In <FIG> and also in the embodiment of <FIG>, the filter mounting interface also includes an inner annular divider section that divides flow between the clean and dirty side of the filter. In one embodiment the annular divider is provided by an end cap and in the other the divider is provided by the baseplate itself. This inner divider section contains a second seal that extends radially outward. As with the outer seal, the inner seal could extend radially inward depending on the configuration or application. In either configuration whether facing inwardly or outwardly, the inner and/or outer seals are considered to be circumscribing.

In <FIG>, the baseplate contains an inner and outer divider section connected by a series of ribs. These ribs and inner divider section could instead be part of the top element end cap and separate from the baseplate as seen in <FIG>. If the ribs and inner section are part of the end cap, the baseplate may be considerably less expensive. An example of a simplified baseplate can be seen <FIG>.

The preferred embodiments shown contain a disposable filter and canister arrangement with a can bent over a shoulder of the baseplate to form a spin-on filter. If the baseplate is steel, a seaming cover could be welded to it and the can seamed to the seaming cover (e.g. a seaming lid technique is shown in in <CIT> entitled "Filter") thereby connecting the baseplate to the filter housing. In either case a baseplate connected to the filter housing at the open end.

The canister could be reusable and made of metal or plastic with a replaceable inner element, and <FIG> is schematically show with a optional cap break <NUM> whereby the closed end may be removable and connectable threaded lid to the remainder of the housing such as via a threaded connection (see e.g. <CIT> illustrating a threaded lid).

Preferably as shown, the housing and the baseplate are separate component parts and not unitarily connected with the baseplate connected to the housing at and proximate the open end of the housing. The housing and the baseplate may also be integrally and/or unitarily connected in an integral housing assembly rather than as separate component parts.

For example, the canister could also be cast out of one piece and the filter dropped in from the top. In this instance a housing assembly would be a high strength plastic or metal (steel, aluminum or magnesium). This design would have the protrusions <NUM> cast to the outside diameter of the housing assembly and the wall <NUM> would extend down the length creating the side wall <NUM>. In this design, the baseplate is also integrally and unitarily connected to the housing at the housing open end which in that case would be where the sidewall portion merges into the baseplate portion.

As shown in <FIG> and <FIG>, the collar is a two-piece collar, but it could be two or more pieces. The cover could be plastic or metal depending on the strength requirements.

The filter base can be a stand-alone base for a frame or engine mount application. It could be molded into a larger casting as well.

Claim 1:
A filter (<NUM>), comprising:
an inlet port (<NUM>);
an outlet port (<NUM>);
a filter element (<NUM>) including a filter media (<NUM>),
a filter housing (<NUM>) having an open end (<NUM>), a closed end (<NUM>) and a sidewall (<NUM>) extending between the open end (<NUM>) and the closed end (<NUM>), the sidewall (<NUM>) disposed around the filter element (<NUM>);
a flow passageway (<NUM>) extending from the inlet port (<NUM>) through the filter media (<NUM>) to the outlet port (<NUM>); and
a baseplate (<NUM>; <NUM>) connected to the filter housing at the open end (<NUM>), the baseplate (<NUM>) including an annular mouth (<NUM>; <NUM>) with the inlet port (<NUM>) and the outlet port (<NUM>) radially inside of the annular mouth (<NUM>), and at least one radial projection (<NUM>) projecting radially from the mouth (<NUM>; <NUM>) between the filter housing (<NUM>) and a distal end of the mouth, wherein the at least one radial projection comprises a plurality of radial projections (<NUM>) in spaced relation with radial gaps (<NUM>) defined between adjacent projections around the mouth (<NUM>; <NUM>), and wherein the plurality of radial projections (<NUM>) project radially outwardly away from the mouth (<NUM>; <NUM>).