US20130068684A1 - Filter unit - Google Patents

Abstract

A filter unit includes a body portion having a proximal end and a distal end. An engagement protrusion extends from the proximal end. The engagement protrusion includes a first portion that has a first radius of curvature and a second portion opposing the first portion that has a second radius of curvature that is larger than the first radius of curvature. A protruding retention surface is disposed on and extends radially outward from the body portion. The protruding retention surface is adapted to secure the filter unit in a filter head assembly.

Description

BACKGROUND OF THE PRESENT INVENTION
• The present invention generally relates to a filter unit, and more specifically, to a filter unit that includes keyed features for interfacing with engagement features on a filter head assembly.
SUMMARY OF THE INVENTION
• In one aspect of the present invention, a filter unit includes a body portion having a proximal end and a distal end. An engagement protrusion extends from the proximal end. The engagement protrusion includes a first portion that has a first radius of curvature and a second portion opposing the first portion that has a second radius of curvature that is larger than the first radius of curvature. A protruding retention surface is disposed on and extends radially outward from the body portion. The protruding retention surface is adapted to secure the filter unit in a filter head assembly.
• In another aspect of the present invention, a filter unit includes a substantially cylindrical body portion having a proximal end and a distal end. An engagement protrusion extends from the proximal end of the cylindrical body portion. First and second distinct retention surfaces are disposed in the cylindrical body portion. A third distinct retention surface is disposed on and extends radially outward from the cylindrical body portion.
• In yet another aspect of the present invention, a filter unit includes a body portion having an exterior wall and having a proximal end and a distal end. An engagement protrusion extends from the proximal end. The engagement protrusion has a cross-section with only one axis of symmetry. A retention surface is disposed on the body portion. The retention surface is defined by one of a radially extending member that protrudes outwardly from the body portion and a groove defined in the exterior wall of the body portion.
• These and other features, advantages, and objects of the present invention will be further understood and appreciated by those skilled in the art upon studying the following specification, claims, and appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a top perspective view of one embodiment of a water filter system of the present invention;
• FIG. 2 is a front perspective view of the water filter system ofFIG. 1 with the water filter withdrawn from the filter head assembly;
• FIG. 3 is a top perspective view of one embodiment of a water filter of the present invention;
• FIG. 3A is an enlarged cross-sectional view of the water filter ofFIG. 3 taken at IIIA-IIIA;
• FIG. 4 is an elevational view of a first side of the water filter ofFIG. 3;
• FIG. 4A is an enlarged elevational view of a first side of a forward casing of the water filter ofFIG. 3;
• FIG. 4B is an enlarged elevational view of a first side of a forward casing of the water filter ofFIG. 3;
• FIG. 5 is a front elevational view of the water filter ofFIG. 3 with casings;
• FIG. 5A is an enlarged view of one embodiment of a laterally extending key member;
• FIG. 5B is an enlarged view of another embodiment of a laterally extending key member;
• FIG. 6 is an elevational view of a second side of the water filter ofFIG. 3;
• FIG. 6A is an enlarged elevational view of a second side of the forward casing of the water filter ofFIG. 3;
• FIG. 6B is an enlarged elevational view of a second side of another embodiment of a forward casing of the water filter ofFIG. 3;
• FIG. 7 is a rear elevational view of the water filter ofFIG. 3;
• FIG. 7A is an enlarged cross-sectional view of the water filter ofFIG. 3 taken at VIIA-VIIA;
• FIG. 8 is a top exploded perspective view of the water filter ofFIG. 3;
• FIG. 9 is a top plan view of the water filter ofFIG. 3;
• FIG. 9A is a top plan view of the water filter ofFIG. 3;
• FIG. 10 is a bottom plan view of the water filter ofFIG. 3;
• FIG. 11 is a top perspective view of one embodiment of a filter head assembly of the present invention;
• FIG. 12 is a front elevational view of the filter head assembly ofFIG. 11;
• FIG. 13 is an elevational view of a first side of the filter head assembly ofFIG. 11;
• FIG. 14 is a rear elevational view of the filter head assembly ofFIG. 11;
• FIG. 15 is an elevational view of a second side of the filter head assembly ofFIG. 11;
• FIG. 16 is a bottom plan view of the filter head assembly ofFIG. 11;
• FIG. 17 is a top plan view of the filter head assembly ofFIG. 11;
• FIG. 17A is a top plan view of another embodiment of the filter head assembly ofFIG. 11;
• FIG. 18 is an exploded top perspective view of the filter head assembly ofFIG. 11;
• FIG. 19 is a bottom exploded perspective view of engaging components of the filter head assembly and filter unit;
• FIG. 20A is an enlarged side perspective view of engaging components of the filter head assembly and filter unit prior to engagement;
• FIG. 20B is a side elevational view of a filter unit prior to engagement with the filter head assembly illustrating the lateral engagement key member and key slot prior to engagement;
• FIG. 20C is a side elevational view of the filter unit prior to engagement with the filter head assembly illustrating the first and second guides and the first and second engagement surfaces prior to engagement;
• FIG. 20D is a cross-sectional view of the filter head assembly ofFIG. 20B taken at XXD-XXD;
• FIG. 20E is a cross-sectional view of the filter head assembly ofFIG. 20C taken at XXE-XXE;
• FIG. 20F is a partial cross-sectional view of the filter head assembly ofFIG. 20C taken at XXF-XXF;
• FIG. 20G is a side cross-sectional view of a filter unit prior to installation into a head assembly;
• FIG. 21A is an enlarged side perspective view of engaging components of the filter head assembly and filter unit during engagement;
• FIG. 21B is a side elevational view of a filter unit during engagement with the filter head assembly illustrating the lateral engagement key member and key slot engaging;
• FIG. 21C is a side elevational view of the filter unit during engagement with the filter head assembly illustrating the first and second guides and engaging the first and second engagement surfaces engaging;
• FIG. 21D is a cross-sectional view of the filter head assembly ofFIG. 21B taken at XXID-XXID;
• FIG. 21E is a cross-sectional view of the filter head assembly ofFIG. 21C taken at XXIE-XXIE;
• FIG. 21F is a partial cross-sectional view of the filter head assembly ofFIG. 21C taken at XXIF-XXIF;
• FIG. 22A is an enlarged side perspective view of engaging components of the filter head assembly and filter unit fully engaged;
• FIG. 22B is a side elevational view of a filter unit in full engagement with the filter head assembly illustrating the lateral engagement key member and key slot fully engaged;
• FIG. 22C is a side elevational view of the filter unit in full engagement with the filter head assembly illustrating the first and second guides and the first and second engagement surfaces fully engaged;
• FIG. 22D is a cross-sectional view of the filter head assembly ofFIG. 22B taken at XXIID-XXIID;
• FIG. 22E is a cross-sectional view of the filter head assembly ofFIG. 22C taken at XXIIE-XXIIE;
• FIG. 22F is a partial cross-sectional view of the filter head assembly ofFIG. 22C taken at XXIIF-XXIIF;
• FIG. 23 is a front elevational view of the water filter system with the water filter fully installed into the filter head assembly;
• FIG. 24 is an enlarged cross-sectional view of the water filter ofFIG. 23 taken at XXIV-XXIV;
• FIG. 25 is an enlarged cross-sectional view of the water filter ofFIG. 17 taken at XXV-XXV; and
• FIG. 26 is a side cross-sectional view of a filter unit fully installed into the filter head assembly.
DETAILED DESCRIPTION OF EMBODIMENTS
• For purposes of description herein the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the invention as oriented inFIGS. 1 and 3. However, it is to be understood that the invention may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise.
• Referring to the embodiment illustrated inFIGS. 1 and 2,reference numeral10 generally designates a water filter system including afilter unit12 having a body portion14 (FIG. 4) having aproximal end16 and adistal end18. Theproximal end16 is adapted to be inserted into afilter head assembly20. A laterally extendingkey member22 is disposed on thebody portion14 and adapted to engage a key slot24 (FIG. 11) in thefilter head assembly20. Anengagement protrusion26 extends from theproximal end16. Theengagement protrusion26 includes afirst portion28 having a first radius of curvature and asecond portion32 opposing thefirst portion28 that includes a second radius of curvature that is larger than the first radius of curvature.
• Referring now toFIGS. 3-4B, thebody portion14 of thefilter unit12 includes a cylinder-like construction having a diameter that is easily graspable by the hand of a user. A multitude of graspingcutouts40 are disposed on thebody portion14 and extend toward thedistal end18 of thebody portion14 and are designed to provide a gripping surface for a user to both engage and disengage thefilter unit12 from thefilter head assembly20. As disclosed in further detail herein, engagement of thefilter unit12 typically includes rotational and longitudinal movement of thefilter unit12 relative to thefilter head assembly20. An internal portion of thefilter unit12 includes a water filter39 having afiltering media41 designed to filter and clean water that passes through thefilter unit12 during use. Thefiltering media41 includes end caps42,43 that secure thefiltering media41 in place in thebody portion14 of thefilter unit12. Theend cap42 includes anoutlet44 that relays filtered water out of thefiltering media41 after the water has been filtered.Seals45 prevent cross-contamination of unfiltered water with filtered water that has passed through thefiltering media41. As shown inFIG. 4B, the distance A from adistal protrusion surface47 of thefilter unit12 to afirst seal74 is approximately 2.69 millimeters. Thefirst seal74 and asecond seal76 have a thickness B of approximately 2.62 millimeters. The distance C between thedistal protrusion surface47 and thesecond seal76 is approximately 18.69 millimeters, while the distance D from thedistal protrusion surface47 to ashoulder support89 is approximately 28.30 millimeters. Finally, the distance E from thedistal protrusion surface47 to the laterally extendingkey member22 is approximately 41.20 millimeters. The dimensions noted above are specifically configured to complement and interact with thefilter head assembly20, thereby allowing for tight and secure engagement of thefilter unit12 with thefilter head assembly20.
• As readily observed inFIG. 5, theengagement protrusion26 is centrally aligned as viewed from the front. However, as illustrated inFIG. 6, theengagement protrusion26 is offset as viewed from the side. Thus, theengagement protrusion26 is generally disposed in an offset position on the proximal end of thefilter unit12. Further, as evidenced inFIG. 5, theoutlet72 is generally aligned with a centrallongitudinal axis109 that extends longitudinally through the center of thefilter unit12. The laterally extendingkey member22 can be constructed in a variety of shapes. For example, the laterally extending key member can include a rectangular shape (FIG. 5A), a cylindrical shape (FIG. 5B), or any other shape adapted to interface with thekey slot24 of thefilter head assembly20. Regardless of the shape, the laterally extendingkey member22 generally has a width of approximately 2.75 millimeters, a height of approximately 2.75 millimeters, and extends approximately 27.73 millimeters from the centrallongitudinal axis109.
• Thebody portion14 of thefilter unit12 is defined by aforward casing46 and arearward casing48 that are placed in abutting engagement over the water filter39 disposed inside thefilter unit12. Theforward casing46 may be attached to therearward casing48 in any known manner, such as by heat staking, welding, or mechanical fastener attachment. Alternatively, it is contemplated that thebody portion14 could include one integral casing formed from a single part. Theengagement protrusion26 extends from theproximal end16 of thefilter unit12 and is smaller in cross-sectional area than thebody portion14 of thefilter unit12. Thebody portion14 tapers gradually from theproximal end16 to thedistal end18.
• The illustrated embodiment ofFIGS. 3-7 depict anelectronic device50 that is disposed on and extends from an outer circumference of thebody portion14 between theproximal end16 and thedistal end18 of thefilter unit12. In the illustrated embodiments, theelectronic device50 includes aprotective cover51 having a triangular-type cross-section with an apex52 of the triangular-type cross-section extending away from thebody portion14 of thefilter unit12. Theelectronic device50 includes apower contact54A, a data contact54B, and aground contact54C. The data contact54B relays information pertaining to thefilter unit12 capacity,filter unit12 usage data, and the number of days until areplacement filter unit12 is needed. Theground contact54C provides a conducting path to a grounding source, which is independent of the normal current-carrying path of theelectronic device50.
• Theelectronic device50 is used in conjunction with asmart filter system56 that includes asmart filter board58 that stores payload information values related to timeout intervals based on hours, minutes, and seconds. These values are used to determine how long a user interface waits for communication from thesmart filter system56 before triggering a replace filter icon. In addition, sync user functionality is used to trigger a configuration of thesmart filter system56. Reconfiguration of thesmart filter system56 may be used to ensure that the application control unit, user interface, and smart filter are all using the same values. This information is all stored in thesmart filter board58 on theelectronic device50.
• Theelectronic device50 may use gold plating, or other conductive metals, on thecontacts54A,54B, and54C. The gold plating ensures a good connection with an extremely low ampere circuit in a potentially moist environment. Connector grease, or an equivalent, may be used to help isolate thecontacts54A,54B, and54C and avoid shorting of thecontacts54A,54B, and54C due to moisture. In addition, theprotective cover51 is implemented to protect thesmart filter board58 after installation into thefilter head assembly20. Thisprotective cover51 also protects the grease prior to being installed into thefilter head assembly20, and provides electrostatic discharge (ESD) protection. As a result of the isolated low voltage application in thesmart filter system56, theelectronic device50 is safe during the installation of thefilter unit12 into thefilter head assembly20.
• Referring toFIGS. 3A and 7A, an engagement orend wall60 of theengagement protrusion26 is integral with asidewall61 of theengagement protrusion26 and has a concave construction that tapers downwardly to an end aperture, which constitutes anoutlet72 of thefilter unit12. A side aperture, which constitutes aninlet70, is positioned in thesidewall61 of theengagement protrusion26. For purposes of description, as viewed inFIGS. 3A and 7A, thefilter unit12 is described in an upright position, wherein the longitudinal axis of thefilter unit12 is in a substantially vertical orientation. In the illustrated embodiment, an angle α₂of theengagement wall60 adjacent to thefirst portion28 has an angle approximately 67.7 degrees from vertical. It is contemplated that the angle α₂could be as low as 15 degrees or as high as 90 degrees. An angle α₁of theengagement wall60 of theengagement protrusion26 at thesecond portion32 of theengagement protrusion26 is approximately 51 degrees, although it is contemplated that the angle α₁could be as low as 5 degrees or as high as 85 degrees. It will be noted that the degrees and constructions of theengagement wall60 may vary from these specified angles and still be within the scope of the present invention. As shown inFIG. 7A, the angle θ of theengagement wall60 in theengagement protrusion26 is approximately 46.9 degrees from vertical on both third andfourth portions64,65 of theengagement protrusion26. It is contemplated that the angle θ could be as low as 10 degrees or as high as 85 degrees. As illustrated, the first andsecond portions28,32 of theengagement protrusion26 are not symmetrical, while the third andfourth portions64,65 of theengagement protrusion26 are generally symmetrical.
• Referring again to the embodiments ofFIGS. 3A and 7A, theinlet70 and theoutlet72 of thefilter unit12 have approximately the same diameter to dissipate extreme water pressure increases or decreases in the system. Nevertheless, it is contemplated that the diameter size of theinlet70 and theoutlet72 could differ. Additionally, theengagement protrusion26 includes first andsecond seals74,76, wherein thefirst seal74 is disposed above theinlet70 near aforward edge78 of theengagement protrusion26, and thesecond seal76 is disposed between theinlet70 and abase portion82 of theengagement protrusion26. Both the first andsecond seals74,76 extend around thesidewall61 of theengagement protrusion26. Thefirst seal74 keeps incoming unfiltered water entering theinlet70 from cross-contaminating with exiting filtered water leaving theoutlet72. Therefore, thefirst seal74 acts as a barrier, keeping the water to be filtered separate from the filtered water. Thesecond seal76 acts as a barrier that prevents filtered water from leaking around thebody portion14 during use.
• Referring now to FIGS.4 and6-7, a shoulder83 (FIG. 8) on theproximal end16 of thefilter unit12 includes the laterally extendingkey member22, which is adapted to interface with and disengage an interference member88 (FIG. 1) disposed in thefilter head assembly20, as outlined in further detail herein. The laterally extendingkey member22, as illustrated, includes a square shape. The laterally extendingkey member22 may extend out from thebody portion14 approximately 0.5 to 10 mm. In the illustrated embodiment, the laterally extendingkey member22 extends out from thebody portion14 approximately 2.75 mm. However, it is contemplated that the shape of the laterally extendingkey member22 could also be circular, oval, polygonal, etc. The laterally extendingkey member22 includes a profile height that is adapted to be received in akey slot24 inside thefilter head assembly20. Thekey slot24 includes three segments that define thekey slot24 shape. A first segment85 (FIG. 11) is substantially linear and parallel with the longitudinal extent of thefilter head assembly20. A second segment87 (FIG. 11) extends at an angel between 0 degrees and 98 degrees relative to the longitudinal extent of thefilter head assembly20. A third segment91 (FIG. 11) extends substantially laterally or normal to the longitudinal extent of thefilter head assembly20. Thethird segment91 may angle back 0 degrees to 25 degrees to provide a detent-type configuration that is adapted to secure the laterally extendingkey member22 in place in thekey slot24 of thefilter head assembly20. Additionally, as shown inFIG. 13, aretention nub91A may be disposed in thethird segment91 to assist in securing the laterally extendingkey member22 in place.
• As shown in the illustrated embodiment ofFIG. 6A, theengagement protrusion26 may include a straight walled construction designed to engage thefilter head assembly20 and be received in afilter head sleeve156. In an alternative embodiment, as illustrated inFIG. 6B, theengagement protrusion26 includes a stepped construction including aledge93 adapted to interface with a complementary receiving ledge95 (FIG. 17A) in thefilter head assembly20. This design ensures that the first andsecond seals74,76 disengage thefilter head assembly20 at the same time.
• As shown generally inFIGS. 4-10, first and second engagement surfaces90,92 are disposed on thefilter unit12 on opposite sides thereof. The illustrated embodiment depicts the first and second engagement surfaces90,92 in the form of channeled grooves. However, it is contemplated that the first and second engagement surfaces90,92 could be formed from externally protruding walls, or a combination of grooves and externally protruding walls, among other possible constructions. The first and second engagement surfaces90,92 are adapted to engage first andsecond guides94,96 (FIG. 11), respectively, juxtapositioned on an interior wall99 (FIG. 17) that defines a receiving cavity100 (FIG. 18) of thefilter head assembly20. Similar to the laterally extendingkey member22, the first and second engagement surfaces90,92 are shown having a square shape. However, it is contemplated that the square shape of the first and second engagement surfaces90,92 could also be circular, oval, polygonal, etc. Similar to thekey slot24, the first and second engagement surfaces90,92 include three segments. Specifically, each of the first and second engagement surfaces90,92 includes afirst segment102 that is substantially linear and parallel with the longitudinal extent of thebody portion14 of thefilter unit12. Asecond segment104 of the first and second engagement surfaces90,92 extends at an angle between 0 degrees and 90 degrees relative to the longitudinal extent of thebody portion14 of thefilter unit12. In the illustrated embodiment, the angle Δ (FIG. 4A) of thesecond segment104 of the first and second engagement surfaces90,92 is 62 degrees from vertical. Athird segment106 of the first and second engagement surfaces90,92 extends substantially laterally or normal to the longitudinal extent of thebody portion14 of thefilter unit12. Alternatively, thethird segment106 may angle back 0 degrees to 25 degrees to provide a detent-type configuration that is adapted to secure the first andsecond guides94,96 in place after engagement of thefilter unit12 with thefilter head assembly20. Each of the first, second, andthird segments102,104, and106 of the first and second engagement surfaces90,92 provide a smooth engagement of thefilter unit12 with thefilter head assembly20 during installation of thefilter unit12, as discussed in further detail herein.
• As shown inFIG. 9, thefirst portion28 of theengagement protrusion26 has a first radius of curvature. Thesecond portion32 of theengagement protrusion26 opposes thefirst portion28 and has a second radius of curvature that is larger than the first radius of curvature. Thus, a cross-section of theengagement protrusion26 taken perpendicular to the longitudinal extent of thefilter unit12 is generally egg-shaped. Stated differently, theengagement protrusion26 includes a cross-section with only one axis of symmetry. Further, the laterally extendingkey member22 is not aligned with, but instead is generally offset from, theinlet70 of theengagement protrusion26. Theshoulder83 of thefilter unit12 is generally rounded. However, theshoulder83 can also be angled or have a more square construction. Alternatively, theshoulder83 may include theshoulder support89 that bears against thefilter head sleeve156. As shown inFIG. 10, thedistal end18 of thefilter unit12 is also generally rounded, but could include other constructions. A substantially planar portion108 (FIG. 7A) is disposed at thedistal end18 of thefilter unit12, and allows thefilter unit12 to be placed in an upright position.
• Referring toFIG. 9A, theoutlet72 of thefilter unit12 is approximately centered or aligned with a central longitudinal axis109 (FIG. 5) that extends centrally through thefilter unit12. A line from the central axis to thefirst portion28 of theengagement protrusion26 is generally defined to be at an angle of zero degrees. The laterally extendingkey member22 is offset at an angle γ approximately 10 degrees from thefirst portion28 of theengagement protrusion26. The angle Φ between thefirst portion28 to thefirst segment102 of thefirst engagement surface90 is approximately 26 degrees. Thefirst segment102 includes an opening that extends across an angle η that is approximately 15 degrees of theshoulder83 of thefilter unit12. Thefirst engagement surface90 extends across an angle β that is approximately 104 degrees from the opening of thefirst segment102 to anabutment wall106A adjacent thethird segment106. Thefirst segment102 of thefirst engagement surface90 is approximately 180 degrees from thefirst engagement surface90 of thesecond engagement surface92. The angle μ taken from a line defined between the centrallongitudinal axis109 to thesecond portion32 is also 26 degrees. Thus, the angle between a line defined between the centrallongitudinal axis109 and thefirst portion28 to thefirst segment102 of thesecond engagement surface92 is 206 degrees (180 degrees plus 26 degrees).
• Referring now toFIGS. 11-16, thefilter head assembly20 includes a filterunit receiving end118 and awater receiving end119. Thefilter head assembly20 has acylindrical receiver120 that is defined by aninterior wall portion120A (FIG. 17) and anexterior wall portion120B. Thecylindrical receiver120 is adapted to receive all or at least a portion of theproximal end16 of thefilter unit12. An external circumference of theinterior wall portion120A includes an inlet port122 (FIG. 18) and an outlet port124 (FIG. 18) defined by opposing inlet andoutlet extension members126,128, respectively. Theinlet extension member126 defines an inlet aperture126A. In the illustrated embodiment, the inlet aperture126A is 0.3125 inches. Theoutlet extension member128 defines an outlet aperture128A. In the illustrated embodiment, the outlet aperture128A is 0.25 inches. Theexterior wall portion120B includes wall slots129 (FIG. 18) that are sized to generally accommodate the inlet andoutlet extension members126,128. Although the inlet andoutlet extension members126,128 are shown on opposite sides of thefilter head assembly20, it is contemplated that the inlet andoutlet extension members126,128 could be at any angle relative to one another and disposed at any position on the external circumference of theinterior wall portion120A. Thecylindrical receiver120 includes anend wall130 positioned on thecylindrical receiver120 proximate thewater receiving end119. Structural supports132 (FIG. 16) are disposed on an external surface of theend wall130. An electronic connector extends from an edge of thecylindrical sidewall132 of thefilter head assembly20 and is adapted for engagement with theelectronic device50 on thefilter unit12. Additionally, aclip134 is positioned on the exterior circumference of thefilter head assembly20 and is designed to support anelectronic connector135 on thefilter head assembly20. Theelectronic connector135 is designed to receive information from and communicate information to theelectronic device50. Theelectronic connector135 is removably connected with theclip134, such as by a snap-fit connection, with theclip134. Thus, theelectronic connector135 can be removed and replaced, if necessary.
• Referring again toFIGS. 11-15, thekey slot24 is formed on an interior side of theexterior wall portion120B. Thekey slot24, as mentioned herein, is designed to receive the laterally extendingkey member22 when thefilter unit12 is being inserted into thefilter head assembly20. In addition, theinterference member88 forms a portion of theexterior wall portion120B, and is designed to prevent a filter unit that lacks a laterally extending key member from engaging thefilter head assembly20. Theinterference member88 includes an abutment catch136 (FIG. 17) disposed at a distal end of theinterference member88 at an interior side of theinterference member88. Theabutment catch136 includes an abutment wall137 (FIG. 17) and asloped wall138. Theinterference member88 is connected to theexterior wall portion120B proximate the filterunit receiving end118. A portion of thekey slot24 extends along an interior side of theinterference member88. As illustrated, theinterference member88 is connected with theexterior wall portion120B by a securing clip140 (FIG. 18). The securingclip140 includes an aperture141 (FIG. 18) adapted to receive a clip protuberance142 (FIG. 18) disposed on theinterference member88. However, it is contemplated that theinterference member88 could be connected in other manners, such as by a living hinge, adhesive, mechanical fasteners, etc.
• Turning now toFIGS. 17-19, thefilter head assembly20 also includes afilter receiver150 with astop member151. Thefilter receiver150 is rotatable inside thefilter head assembly20 between a filtering position152 (FIG. 22D) and a bypass position154 (FIG. 20D), wherein unfiltered water passes through thefilter head assembly20 when thefilter unit12 is not installed. Thefilter head assembly20 also includes thefilter head sleeve156, which has a cross-section that complements the shape of theengagement protrusion26. Generally stated, the cross-section of thefilter head sleeve156 is egg-shaped. More specifically, thefilter head sleeve156 includes afirst portion158 that includes a first radius of curvature and asecond portion159 opposing thefirst portion158 that includes a second radius of curvature that is larger than the first radius of curvature. Thus, thefilter head sleeve156 includes a cross-section with only one axis of symmetry. Thefilter head sleeve156 is sized slightly larger than theengagement protrusion26 such that thefilter head sleeve156 can closely receive and retain theengagement protrusion26 and maintain a watertight seal with the aid of the first andsecond seals74,76.
• In an alternative embodiment, as illustrated inFIG. 17A, thefilter head sleeve156 may include the stepped construction briefly mentioned above with reference toFIG. 6A, such that thefilter head sleeve156 includes the receivingledge95, which is adapted to engage and abut theledge93 on theengagement protrusion26. During insertion, the stepped construction of both thefilter head sleeve156 and theengagement protrusion26 allows the first andsecond seals74,76 to engage thefilter head sleeve156 simultaneously. Similarly, during removal, the stepped construction allows the first andsecond seals74,76 to disengage thefilter head sleeve156 simultaneously.
• Referring again toFIGS. 17-19, thefilter receiver150 includes afiltering pathway155 and abypass channel157. Thebypass channel157 allows water to flow through thefilter head assembly20 without being filtered. Thefilter head sleeve156 of thefilter receiver150 is disposed inside thefilter head assembly20. The inlet andoutlet extension members126,128 includecouplings160,162 adapted to interface with aninlet water conduit172 and anoutlet water conduit178, respectively. Thecoupling160 includes aninsert170 that connects with theinlet extension member126. Theinsert170 is sealed by agasket174. Thecoupling162 includes aninsert176 that connects with theoutlet extension member128. Theinsert176 is sealed by agasket180. Thegaskets174,180 of the inlet andoutlet extension members126,128, respectively, keep water from leaking out of the inlet andoutlet extension members126,128.
• Referring toFIGS. 19 and 20A, during installation of thefilter unit12 with thefilter head assembly20, thefilter unit12 is oriented such that theengagement protrusion26 is aligned with thefilter receiver150 and specifically aligned with thefilter head sleeve156, which includes an egg-shaped cross-section that complements the egg-shaped cross-section of theengagement protrusion26, as outlined herein. Alignment of theengagement protrusion26 with thefilter head sleeve156 results in alignment of the laterally extendingkey member22 with thekey slot24, as well as alignment of the first andsecond guides94,96 with the first and second engagement surfaces90,92, as shown inFIGS. 20B,20C, and20E. In this position, theabutment catch136 on theinterference member88 is in aninterference position200, as shown inFIGS. 20D and 20F. In addition, theengagement protrusion26 is in only slight engagement with thefilter head sleeve156 of thefilter receiver150, as shown inFIG. 20G.
• Referring now toFIGS. 21A-21C, linear movement of thefilter unit12 into thefilter head assembly20 generally occurs until the laterally extendingkey member22 begins to transition from thefirst segment85 into thesecond segment87 of thekey slot24. At the same time, the first andsecond guides94,96 are transitioning from thefirst segment102 of the first and second engagement surfaces90,92, respectively, into thesecond segment104 of the first and second engagement surfaces90,92, respectively. As the laterally extendingkey member22 transitions into thesecond segment87 and the first andsecond guide members94,96 transition into thesecond segment104 of the first and second engagement surfaces90,92, thefilter unit12 begins to rotate clockwise into thefilter head assembly20. Because thesecond segment87 of thekey slot24 is at an angle relative to the longitudinal extent of thefilter head assembly20, and also because thesecond segment104 of the first and second engagement surfaces90,92 is at the same general angle as thesecond segment87 of thekey slot24, thefilter unit12 begins to draw into thefilter head assembly20, as shown inFIGS. 21B and 21C. At the same time, theengagement protrusion26 has engaged and is partially inserted into thefilter head sleeve156. Because thefilter unit12 is rotating into thefilter head assembly20, theengagement protrusion26 subsequently rotates thefilter head sleeve156 and thefilter receiver150 as thefilter unit12 is drawn into the filter head assembly20 (FIGS. 21D and 21E).
• As shown inFIGS. 21A,21B, and21F, as the laterally extendingkey member22 passes through thesecond segment87 of thekey slot24, the laterally extendingkey member22 passes by theinterference member88. As the laterally extendingkey member22 passes by theinterference member88, the laterally extendingkey member22 abuts theinterference member88 and forces theinterference member88 outward, thereby moving theabutment wall137 on theabutment catch136 from theinterference position200 to anon-interference position202. When theinterference member88, and consequently theabutment wall137 on theabutment catch136, is moved to thenon-interference position202, thestop member151 disposed on thefilter receiver150 is free to rotate past theinterference member88, and consequently theabutment catch136. Absent the laterally extendingkey member22, which abuts theinterference member88 and forces it outward, theabutment wall137 on theabutment catch136 would remain in theinterference position200, thereby preventing thestop member151 on thefilter receiver150 from rotating past theinterference member88. Consequently, thefilter unit12 would be unable to move from the bypass position154 (FIGS. 20A-20G) to the filtering position152 (FIGS. 22A-22G).
• Referring now toFIGS. 22A-22D, after thestop member151 has cleared theabutment catch136 on theinterference member88, the laterally extendingkey member22 moves past theinterference member88 and begins to transition into thethird segment91 of thekey slot24. At the same time, the first andsecond guides94,96 transition into thethird segment106 of the first and second engagement surfaces90,92. As the laterally extendingkey member22 engages astop wall204 in thekey slot24, the first andsecond guides94,96 engage theabutment wall106A (FIGS. 22E and 22F) in thethird segment106 of the first and second engagement surfaces90,92. Theretention nub91A assists in securing the laterally extendingkey member22 against thestop wall204 of thekey slot24.
• As shown inFIGS. 23-26, thefilter unit12 is now fully inserted into thefilter head assembly20 and thebypass channel157 has been fully rotated out of alignment with theinlet extension member126 and theoutlet extension member128. Consequently, water that flows into thefiltering pathway155 flows into thefilter unit12 through theinlet70 through thesidewall61 and into the water filter39. The water then passes through thefiltering media41 and into a central column of thefilter unit12, where the water flows past theoutlet44 of the water filter39 into theoutlet72 of thefilter unit12. The filtered water then passes into the filteredwater pathway155 of thefilter receiver150 and exits out theoutlet extension member128 to a water line. The water line then relays the filtered water to a dispenser, where it is available for consumption by a user.
• When thefilter unit12 is to be replaced, thefilter unit12 is rotated counterclockwise and the reverse steps disclosed above are conducted. Notably, the laterally extendingkey member22 does not move theinterference member88 out of theinterference position200 for thestop member151 during removal. This step is unnecessary as thestop member151 engages the slopedwall138 of theabutment catch136. Consequently, as a result of the slopedwall138 construction, thestop member151 is able to force theinterference member88 to thenon-interference position202 without the assistance of the laterally extendingkey member22. Thefilter unit12 is then rotated counterclockwise until thefilter unit12 can be withdrawn in a linear motion from thefilter head assembly20.
• In the illustrated embodiment, thewater filter system10 is adapted to receive afilter unit12, which is fully inserted by a quarter turn installation. It is contemplated that the lengths of the segments of the first and second engagement surfaces90,92, as well as the lengths of the first, second, andthird segments85,87, and91 of thekey slot24 may vary such that the turning radius may be greater than or less than one quarter turn of thefilter unit12 relative to thefilter head assembly20.
• It will be understood by one having ordinary skill in the art that thewater filter system10, as described herein, can be used in a variety of appliances, such as refrigerators, dishwashers, and clothes washers and dryers. Further, it will be understood that thewater filter system10 can be used for a variety of applications, such as a second stage water filter for a dishwater, a water steam filter for an oven, and a water cleaning filter for consumption by a user out of a refrigerator. These are examples only and are not meant to be limiting.
• The above description is considered that of the illustrated embodiments only. Modifications of the invention will occur to those skilled in the art and to those who make or use the invention. Therefore, it is understood that the embodiments shown in the drawings and described above is merely for illustrative purposes and not intended to limit the scope of the invention, which is defined by the following claims as interpreted according to the principles of patent law, including the Doctrine of Equivalents.

Claims (20)

The invention claimed is:

1. A filter unit comprising:

a body portion having a proximal end and a distal end;

an engagement protrusion extending from the proximal end, the engagement protrusion having a first portion that includes a first radius of curvature and a second portion opposing the first portion that includes a second radius of curvature that is larger than the first radius of curvature; and

a protruding retention surface disposed on and extending radially outward from the body portion, the protruding retention surface adapted to secure the filter unit in a filter head assembly.

2. The filter unit ofclaim 1, further comprising:

a first recessed retention surface disposed on the body portion, the first recessed retention surface adapted to secure the filter unit in the filter head assembly.

3. The filter unit ofclaim 2, further comprising:

a second recessed retention surface disposed on the body portion, the second recessed retention surface adapted to secure the filter unit in the filter head assembly.

4. The filter unit ofclaim 3, wherein the first recessed retention surface and the second recessed retention surface are on substantially opposing sides of the body portion.

5. The filter unit ofclaim 1, further comprising:

a central axis extending substantially centrally through the longitudinal extent of the filter unit, wherein a first plane is defined between the central axis and the first portion of the engagement protrusion and a second plane is defined between the central axis and the protruding retention surface, and wherein the angle between the first plane and the second plane is approximately 10 degrees.

6. The filter unit ofclaim 1, further comprising:

a central axis extending substantially centrally through the longitudinal extent of the filter unit, wherein a first plane is defined between the central axis and the first portion of the engagement protrusion and a second plane is defined between the central axis and the first recessed retention surface, and wherein the angle between the first plane and the second plane is approximately 26 degrees.

7. The filter unit ofclaim 1, wherein the distance from a top edge of the engagement protrusion to the protruding retention surface is approximately 41.2 millimeters.

8. The filter unit ofclaim 2, wherein the distance from a top edge of the engagement protrusion to the first recessed retention surface is approximately 62.8 millimeters.

9. A filter unit comprising:

a substantially cylindrical body portion having a proximal end and a distal end;

an engagement protrusion extending from the proximal end of the cylindrical body portion;

first and second distinct retention surfaces disposed in the cylindrical body portion; and

a third distinct retention surface disposed on and extending radially outward from the cylindrical body portion.

10. The filter unit ofclaim 9, wherein the first and second distinct retention surfaces are defined by first and second grooves disposed in the cylindrical body portion.

11. The filter unit ofclaim 9, wherein the distance from a top edge of the engagement protrusion to the third retention surface is approximately 41.2 millimeters.

12. The filter unit ofclaim 11, wherein the distance from a top edge of the engagement protrusion to the first retention surface is approximately 62.8 millimeters.

13. The filter unit ofclaim 10, further comprising:

a central axis extending substantially centrally through the longitudinal extent of the filter unit; and

an outlet disposed on the engagement protrusion, wherein the central axis extends through the outlet.

14. The filter unit ofclaim 9, wherein the first and second distinct retention surfaces are disposed on substantially opposing sides of the cylindrical body portion.

15. A filter unit comprising:

a body portion including an exterior wall and having a proximal end and a distal end;

an engagement protrusion extending from the proximal end, the engagement protrusion having a cross-section with only one axis of symmetry; and

a retention surface disposed on the body portion, the retention surface defined by one of:

a radially extending member that protrudes outwardly from the body portion; and

a groove defined in the exterior wall of the body portion.

16. The filter unit ofclaim 15, further comprising:

a central axis extending substantially centrally through the longitudinal extent of the filter unit, wherein a first plane is defined between the central axis and the first portion of the engagement protrusion and a second plane is defined between the central axis and the retention surface, and wherein the angle between the first plane and the second plane is approximately 10 degrees.

17. The filter unit ofclaim 15, further comprising:

a central axis extending substantially centrally through the longitudinal extent of the filter unit, wherein a first plane is defined between the central axis and the first portion of the engagement protrusion and a second plane is defined between the central axis and the retention surface, and wherein the angle between the first plane and the second plane is approximately 26 degrees.

18. The filter unit ofclaim 15, wherein the distance from a top edge of the engagement protrusion to a first gasket is approximately 2.7 millimeters.

19. The filter unit ofclaim 18, wherein the distance from the top edge of the engagement protrusion to a second gasket is approximately 18.7 millimeters.

20. The filter unit ofclaim 18, wherein the distance from the top edge of the engagement protrusion to the retention surface is approximately 41.2 millimeters.

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