Abstract: A water filter includes a filter unit having a body portion adapted to be rotatingly received into a filter head assembly. An engagement protrusion extends from the body portion and is adapted for reception in a complementary receiver in the filter head assembly. An electronic device is disposed on the filter unit having a memory storage unit. A laterally extending key member is disposed on the body portion between the first engagement surface and the second engagement surface. The laterally extending key member is adapted to reposition an interference member from an interference position, whereby the body portion can be fully inserted into the filter head assembly to a non-interference position, whereby the body portion can be fully inserted into the filter head assembly.

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.

Abstract: A method of installing a filter unit includes aligning a filter unit into a filter head assembly. The filter unit includes a laterally extending key member and an engagement protrusion. 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 larger than the first radius of curvature. The laterally extending key member is aligned into a key slot in the filter head assembly. An engagement surface is aligned on the filter unit into a complementary engagement surface on the filter head assembly. The filter unit is rotatingly inserted into the filter head assembly. The laterally extending key member shifts an interference member on the filter head assembly from an interference position, wherein the filter unit cannot sealingly engage the filter head assembly, to a non-interference position, wherein the filter unit can sealingly engage the filter head assembly.

Abstract: A water filter system includes a removable filter unit having a body portion including a proximal end and a distal end. The proximal end is adapted to be inserted into a filter head assembly. A laterally extending key member is disposed on the body portion and adapted to engage a key slot in the filter head assembly. 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 includes a second radius of curvature that is larger than the first radius of curvature.

Abstract: A water filter system includes a removable filter unit having a body portion including a proximal end and a distal end. The proximal end is adapted to be inserted into a filter head assembly. A laterally extending key member is disposed on the body portion and adapted to engage a key slot in the filter head assembly. 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 includes a second radius of curvature that is larger than the first radius of curvature.

Abstract: A water filter includes a filter unit having a body portion adapted to be rotatingly received into a filter head assembly. An engagement protrusion extends from the body portion and is adapted for reception in a complementary receiver in the filter head assembly. An electronic device is disposed on the filter unit having a memory storage unit. A laterally extending key member is disposed on the body portion between the first engagement surface and the second engagement surface. The laterally extending key member is adapted to reposition an interference member from an interference position, whereby the body portion can be fully inserted into the filter head assembly to a non-interference position, whereby the body portion can be fully inserted into the filter head assembly.

Abstract: Described in this application is an improved cartridge, such as a water filter, and housing for the filter. The filter is preferably of the push-in type and the filter housing includes an assembly to automatically set the water filter in position as a cover over the filter is closed. According to one embodiment, the assembly consists of a cover and lever linkage which engage complimentary protrusions on the water filter.

Abstract: A filter unit includes a body portion having a proximal end and a distal end. First and second engagement surfaces traverse at least part of the body portion. The first and second engagement surfaces include a first segment that extends substantially parallel with the longitudinal extent of the body portion. A second segment extends at an angle relative to the longitudinal extent of the body portion. A third segment extends at a different angle than the second segment. A laterally extending key member is disposed on the body portion between the first engagement surface and the second engagement surface. An engagement protrusion extends from the proximal end. The engagement protrusion has 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.

Abstract: A water filter system includes a filter unit having a body portion adapted to be rotatingly received into a filter head assembly. An engagement protrusion extends from the body portion and is adapted for reception in a complementary receiver in the filter head assembly. An electronic device is disposed on the filter unit having a memory storage unit. A laterally extending key member is disposed on the body portion between the first engagement surface and the second engagement surface. The laterally extending key member is adapted to reposition an interference member from an interference position, whereby the body portion can be fully inserted into the filter head assembly to a non-interference position, whereby the body portion can be fully inserted into the filter head assembly.

Abstract: A filter unit includes a substantially cylindrical body portion having a proximal end and a distal end. First and second recessed engagement surfaces traverse at least part of the body portion. The first and second engagement surfaces include a first segment that extends substantially parallel with the longitudinal extent of the body portion. A second segment extends at an angle between 50 degrees and 60 degrees from the direction of the first segment. A third segment extends substantially orthogonal to the first segment. A laterally extending key member is disposed on the body portion between the first recessed engagement surface and the second recessed engagement surface. An engagement protrusion extends from the proximal end and has a sidewall with a water inlet and a concave engagement wall with a water outlet. The engagement wall includes a first portion that angles inward to the water outlet at a first angle.

Abstract: 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 body portion. A laterally extending key member is disposed on the body portion. At least one engagement surface traverses at least part of the body portion. The at least one engagement surface includes a first segment that extends substantially parallel with the longitudinal extent of the body portion. A second segment extends at an angle relative to the longitudinal extent of the body portion. A third segment extends at a different angle than the second segment.

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.

Abstract: A method of installing a filter unit includes aligning a filter unit into a filter head assembly. The filter unit includes a laterally extending key member and an engagement protrusion. 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 larger than the first radius of curvature. The laterally extending key member is aligned into a key slot in the filter head assembly. An engagement surface is aligned on the filter unit into a complementary engagement surface on the filter head assembly. The filter unit is rotatingly inserted into the filter head assembly. The laterally extending key member shifts an interference member on the filter head assembly from an interference position, wherein the filter unit cannot sealingly engage the filter head assembly, to a non-interference position, wherein the filter unit can sealingly engage the filter head assembly.

Abstract: A water filter system includes a filter unit having a body portion adapted to be rotatingly received into a filter head assembly. An engagement protrusion extends from the body portion and is adapted for reception in a complementary receiver in the filter head assembly. An electronic device is disposed on the filter unit having a memory storage unit. A laterally extending key member is disposed on the body portion between the first engagement surface and the second engagement surface. The laterally extending key member is adapted to reposition an interference member from an interference position, whereby the body portion can be fully inserted into the filter head assembly to a non-interference position, whereby the body portion can be fully inserted into the filter head assembly.

Abstract: A water filter system includes a removable filter unit having a body portion including a proximal end and a distal end. The proximal end is adapted to be inserted into a filter head assembly. A laterally extending key member is disposed on the body portion and adapted to engage a key slot in the filter head assembly. 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 includes a second radius of curvature that is larger than the first radius of curvature.

Abstract: A filter unit includes a substantially cylindrical body portion having a proximal end and a distal end. First and second recessed engagement surfaces traverse at least part of the body portion. The first and second engagement surfaces include a first segment that extends substantially parallel with the longitudinal extent of the body portion. A second segment extends at an angle between 50 degrees and 60 degrees from the direction of the first segment. A third segment extends substantially orthogonal to the first segment. A laterally extending key member is disposed on the body portion between the first recessed engagement surface and the second recessed engagement surface. An engagement protrusion extends from the proximal end and has a sidewall with a water inlet and a concave engagement wall with a water outlet. The engagement wall includes a first portion that angles inward to the water outlet at a first angle.

Abstract: A filter unit includes a body portion having a proximal end and a distal end. First and second engagement surfaces traverse at least part of the body portion. The first and second engagement surfaces include a first segment that extends substantially parallel with the longitudinal extent of the body portion. A second segment extends at an angle relative to the longitudinal extent of the body portion. A third segment extends at a different angle than the second segment. A laterally extending key member is disposed on the body portion between the first engagement surface and the second engagement surface. An engagement protrusion extends from the proximal end. The engagement protrusion has 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.

Abstract: A filter unit includes a body portion having a proximal end and a distal end and a shoulder disposed therebetween. An engagement protrusion extends from the proximal end. The engagement protrusion includes a sidewall with a water inlet and an engagement wall with a water outlet. A cross-section of the engagement protrusion taken orthogonal to the longitudinal extent of the filter unit has only one axis of symmetry. A first engagement surface traverses approximately one-quarter of an outside circumference of the body portion. A second engagement surface traverses approximately one-quarter of an outside circumference of the body portion opposite the first engagement surface. A laterally extending key member is disposed on the body portion proximate the shoulder. An electronic device is positioned on the body portion adapted to store usage information relating to the capacity and usage of the filter unit.