A fluid treatment device has an exchangeable treatment unit and a connection head. A bayonet-type connection device connects connection head and treatment unit to each other by a plug-in/rotation movement about a connection axis of the treatment device and is provided with a housing connection part and a head connection part that operatively engage each other to form a connection of the bayonet-type connection device. Housing connection part and head connection part each have a mutually complementary functional element extending circumferentially about the connection axis and operatively connectable to each other. The bayonet-type connection device has a pretension element for realizing a mechanical pretension pressing the functional elements against each other. A splash guard part is provided that covers at least the connection device.

A water tank for a domestic appliance, having a tank base, wherein there is provided on the tank base, for the sealed connection of a filter cartridge, an annular tank sealing surface which surrounds a tank passage opening for the flow of water through the wall of the tank base to the domestic appliance, characterized in that a water passage which bypasses the tank sealing surface is provided from outside the tank sealing surface inward to the tank passage opening, which water passage can be closed by a filter-side actuation element upon insertion of the filter cartridge, in that the tank sealing surface and/or the filter sealing surface of the filter cartridge have a varying radius in relation to a central axis (A), such that the tank sealing surface and/or the filter sealing surface comprise radial indentations and/or radial protuberances.

A water tank for a household appliance having a connection for a filter cartridge, wherein an annular tank sealing face is provided on the tank bottom for the tight connection of the filter cartridge and the tank sealing face encloses a tank passage opening for the water from the filter cartridge to flow through the wall of the tank bottom to the household appliance, characterized in that the tank sealing face along its circumference has a variable radius in relation to a central axis, so that the tank sealing face comprises radial concavities and/or radial convexities, wherein the convexities and/or concavities have a round profile, and wherein the concavities and/or convexities are configured to periodically oscillate around a circular line.

A filtration system interconnection structure having a filter manifold and a filter cartridge in magnetic communication with one another, such that a latching mechanism and latch blocking structure in the manifold secures the filter cartridge with a manifold sump when the filter cartridge is inserted within the manifold sump. The magnetic communication is formed between two complementary coded magnets capable of producing a magnetic shear force when in close proximity to one another. The magnetic shear force removes the latching blocking structure from interfering with the latch, allowing the latch to secure the filter cartridge. Movement of the latching blocking structure coded magnet relative to the filter cartridge coded magnet may be perpendicular or parallel with respect to each other. The filter magnet polarity transitions are aligned with the manifold magnet polarity transitions such that a shear force is generated between the magnets when the filter cartridge is inserted within the manifold sump housing, allowing for actuation of the latch blocking mechanism against a biasing force, and allowing the latch to move radially inwards against a separate biasing force.

A filtration system interconnection structure having a filter manifold and a filter cartridge in magnetic communication with one another, such that a latching mechanism and latch blocking structure in the manifold secures the filter cartridge with a manifold sump when the filter cartridge is inserted within the manifold sump. The magnetic communication is formed between two complementary coded magnets capable of producing a magnetic shear force when in close proximity to one another. The magnetic shear force removes the latching blocking structure from interfering with the latch, allowing the latch to secure the filter cartridge. Movement of the latching blocking structure coded magnet relative to the filter cartridge coded magnet may be perpendicular or parallel with respect to each other. The filter magnet polarity transitions are aligned with the manifold magnet polarity transitions such that a shear force is generated between the magnets when the filter cartridge is inserted within the manifold sump housing, allowing for actuation of the latch blocking mechanism against a biasing force, and allowing the latch to move radially inwards against a separate biasing force.

A fluid treatment device has an exchangeable treatment unit and a connection head. A bayonet-type connection device connects connection head and treatment unit to each other by a plug-in/rotation movement about a connection axis of the treatment device and is provided with a housing connection part and a head connection part that operatively engage each other to form a connection of the bayonet-type connection device. Housing connection part and head connection part each have a mutually complementary functional element extending circumferentially about the connection axis and operatively connectable to each other. The bayonet-type connection device has a pretension element for realizing a mechanical pretension pressing the functional elements against each other. The pretension element is a spring element with outwardly projecting spring arms with radially outer end faces provided with a straight section that is tangential to a rim extending in circular shape around the connection axis.

A fluid treatment device has an exchangeable treatment unit and a connection head. A bayonet-type connection device connects connection head and treatment unit to each other by a plug-in/rotation movement about a connection axis of the treatment device and is provided with a housing connection part and a head connection part that operatively engage each other to form a connection of the bayonet-type connection device. Housing connection part and head connection part each have a mutually complementary functional element extending circumferentially about the connection axis and operatively connectable to each other. The bayonet-type connection device has a pretension element for realizing a mechanical pretension pressing the functional elements against each other. The pretension element is a spring element with outwardly projecting spring arms with radially outer end faces provided with a straight section that is tangential to a rim extending in circular shape around the connection axis.

A filter system for liquid has a filter head with drainage channel and stop element. A filter cartridge is mounted by screw-in movement at the filter head and has a support ring rotatably fastened to its housing part. The support ring has an eccentric closure element and a first positioning element guided toward the stop element by the screw-in movement to position the support ring at the filter head in a rotational position for axially aligning closure element and drainage channel. The closure element is transferred axially into a sealing seat at the filter head to close the drainage channel when screwing on the filter cartridge. The support ring has a second positioning element holding the support ring in a rotationally fixed position at the filter head when unscrewing the filter cartridge so that the closure element is moved out of the sealing seat only in an axial direction.

A filter system for liquid has a filter head with drainage channel and stop element. A filter cartridge is mounted by screw-in movement at the filter head and has a support ring rotatably fastened to its housing part. The support ring has an eccentric closure element and a first positioning element guided toward the stop element by the screw-in movement to position the support ring at the filter head in a rotational position for axially aligning closure element and drainage channel. The closure element is transferred axially into a sealing seat at the filter head to close the drainage channel when screwing on the filter cartridge. The support ring has a second positioning element holding the support ring in a rotationally fixed position at the filter head when unscrewing the filter cartridge so that the closure element is moved out of the sealing seat only in an axial direction.

A filter cartridge for a household appliance, which is provided with a filter housing, the wall of which separates a housing internal side from a housing external side. A filter inlet opening which in the operation of the filter cartridge is open in relation to the external environment of the filter housing. A device for water conduction which comprises at least one filter chamber having at least one filter medium and terminates in a filter outlet opening for suctioning water from the filter cartridge in the interior of the filter housing downstream of the filter inlet opening relative to the flow direction during operation. A filter connection element having an annular filter port which has an annular filter sealing face for the tight connection of the filter cartridge to a tank sealing face in the water tank.