Abstract: A filter unit includes a body portion and an engagement protrusion that extends from the body portion with a first water containment seal. At least one cross-section of the engagement protrusion at a location of the first water containment seal, taken perpendicular to a central longitudinal axis of the body portion, includes an egg-shaped outer perimeter with a single axis of symmetry. At least one engagement surface traverses around at least part of the body portion. The at least one engagement surface has a linear movement section for linear movement of the body portion. The linear movement section transitions to a rotational movement section for rotational movement of the body portion. The rotational movement section is angled relative to the linear movement section. A water inlet path and a water outlet path extend through a portion of the engagement protrusion defined by the at least one cross-section.

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 with a proximal end and a distal end. First and second engagement surfaces traverse at least a part of the body portion. The first and second engagement surfaces include a first segment that extends substantially parallel with a longitudinal extent of the body portion and a second segment that extends at an angle relative to the first segment. An engagement protrusion extends from the proximal end of the body portion and has a water inlet and a concave engagement wall with a water outlet. A periphery of the engagement wall includes a first portion with a first radius of curvature and a second portion with a second radius of curvature that is larger than the first radius of curvature. First and second seals are disposed about the engagement protrusion. The water inlet is disposed between the first and second seals.

Abstract: A water filter unit includes a body portion, a first engagement surface that traverses at least part of the body portion, and a second engagement surface that traverses at least part of the body portion opposite the first engagement surface. An engagement protrusion extends from the body portion and has a water inlet and a water outlet. A curved engagement surface is disposed on the engagement protrusion proximate the water outlet. A first seal is disposed on the engagement protrusion. A first cross-section of the engagement protrusion, taken at the first seal and perpendicular to a longitudinal extent of the body portion, has only one axis of symmetry. A second seal is disposed on the engagement protrusion and is spaced apart from the first seal. The water inlet is positioned between the first and second seals.

Abstract: A filter unit includes a body portion with first and second engagement surfaces that traverse at least a part of the body portion. The first and second engagement surfaces include a first segment that extends substantially parallel with a longitudinal extent of the body portion and a second segment that extends at an angle relative to the first segment. An engagement protrusion extends from the body portion and has a water inlet and a concave engagement wall with a water outlet. A periphery of the concave engagement wall includes a first portion with a first radius of curvature and a second portion with a second radius of curvature that is larger than the first radius of curvature. A first seal is disposed on a sidewall of the engagement protrusion proximate the water outlet. A first cross-section of the engagement protrusion, taken at the first seal and perpendicular to the longitudinal extent of the body portion, is egg-shaped with only one axis of symmetry.

Abstract: A filter unit includes a body portion and an engagement protrusion that extends from the body portion with a first water containment seal. At least one cross-section of the engagement protrusion at a location of the first water containment seal, taken perpendicular to a central longitudinal axis of the body portion, includes an egg-shaped outer perimeter with a single axis of symmetry. At least one engagement surface traverses around at least part of the body portion. The at least one engagement surface has a linear movement section for linear movement of the body portion. The linear movement section transitions to a rotational movement section for rotational movement of the body portion. The rotational movement section is angled relative to the linear movement section. A water inlet path and a water outlet path extend through a portion of the engagement protrusion defined by the at least one cross-section.

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 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 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 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 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 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.