Patent Description:
The invention further concerns a sanitary fitting using such a valve cartridge.

It is common knowledge to use valve cartridges in sanitary fittings. Such valve cartridges are separate self-contained components which include all the necessary elements of a valve to provide the valve function of the sanitary fitting. Valve cartridges therefore allow fast maintenance in case of a functional failure of the valve because the valve cartridge may be easily extracted from a base body of the sanitary fitting and exchanged by a new functional valve cartridge.

Furthermore, valve cartridges allow to retrospectively equip a sanitary fitting with different valve functions like e.g. a lever faucet valve, a turning spindle valve, a single lever mixing valve or even a thermostat valve.

Generally, a sanitary fitting which uses a valve cartridge comprises a cartridge seat having a defined interface for connecting water ways of the sanitary fitting with water ways of the valve cartridge. the cartridge seat comprises a given number of water connection seat openings, e.g. a hot water inlet, a cold water inlet and a mixed water outlet (as seen from the cartridge).

On the other hand, the valve cartridge comprises water connection openings which are arranged complementary to the water connection seat openings such that water may be directed from the sanitary fitting into the valve cartridge and according to the setting of the valve out of the valve cartridge back into the sanitary fitting.

It is also common practice to provide all water connection openings of the valve cartridge on the same side of a housing main body of the valve cartridge. Often the water connection openings point longitudinally away from the bottom of the valve cartridge. In this case, the cartridge may be fastened along its longitudinal axis e.g. by means of a screwable fasten ring into the sanitary fitting. By placing an axial bottom sealing intermediate the valve cartridge and the cartridge seat of the sanitary fitting, the fastening force exerted by the fastening ring at the same time causes a fluid tight sealing of the water connection openings.

Although such an arrangement works under normal conditions, it turned out that in some combinations of sanitary fittings and valve cartridges the bottom sealing may become leaky after some time.

From <CIT> a valve cartridge is known which comprises a sliding frame as a bottom part. The sliding frame is slidable with respect to rest of the valve cartridge housing. The sliding frame supports separate sealings on both of its opposing sides, namely towards a valve disc above the sliding frame and towards the cartridge seat of the sanitary fitting below the sliding frame. This allows to fix the play within the disc stack and at the same time to provide reasonable sealing against the cartridge seat.

From <CIT> a valve cartridge is known which comprises an adapter gasket. The adapter gasket may be placed in different orientations between the bottom of the cartridge and the cartridge seat in order to swap the hot and cold water inlet pathways. To this purpose, the adapter gasket is placed in between upper and lower sealings and axially positions itself depending on the fixation force exerted on the cartridge and the involved elasticities of the sealings.

Further valve cartridge sealings are known from <CIT>, <CIT> and <CIT>.

It is therefore an object of the present invention to provide a valve cartridge which has a reduced risk for a leaking bottom sealing.

This object is achieved by a valve cartridge according to claim <NUM>.

The inventor has realized that in the arrangement according to the state of the art a varying axial gap exists between the valve cartridge and the cartridge seat of the sanitary fitting because of manufacturing tolerances and the compressibility of the axial bottom sealing. Therefore, pressure hammers within the water lines may transversely displace the axial bottom sealing into this axial gap such that the sealing fails.

The inventor further has realized that it is not possible to provide a fixed confinement structure around the bottom sealing in order to prevent this transversal displacement caused by pressure hammers: Because of the varying gap it is not possible to provide such a confinement structure all across the gap. If the confinement structure would protrude too much from the valve housing the fastening force would not provide enough pressure on the bottom sealing. If the confinement structure would too small in height an axial gap large enough may exist (depending on the manufacturing tolerances) which allows the bottom sealing to be transversely displaced. In particular, parts of the bottom sealing could move radially outward in the gap which causes leakage.

Therefore, the inventor provided a sealing confiner element, which is movable relative to the housing main body such that, in particular during fastening of the valve cartridge inside the sanitary fitting, the sealing confiner element may longitudinally slide like a telescope. This approach allows to transversely confine a sealing ring of the bottom sealing even across a varying gap between a bottom of the housing main body and the cartridge seat, because the sealing confiner element provides a transversal stop for the sealing ring. This restricts transversal, in particular radial, movements of the sealing ring.

A sealing ring in the context of this invention is a compressible sealing structure which surrounds one of the at least water connection openings. Usually, such a sealing ring is formed in one piece, but in the context of this invention the sealing ring may also comprise several pieces as long as this allows sufficient tightness. Furthermore, the bottom sealing ring may substantially have a ring shape. However, the bottom sealing does not necessarily have to be circular. Instead the overall shape of the ring may be oval, kidney-shaped or even a rounded rectangle depending on the shape of the water connection opening. Finally, due to the fact that a cartridge often includes two or three water connection openings, more than one sealing ring may be need and such sealing rings are often integrally formed in one piece and are together referred to as the bottom sealing or bottom sealing unit.

Advantageously, the valve cartridge comprises a number of valve elements within the housing main body, wherein the play of these valve elements can be set independently from a force acting on the sealing ring between the housing main body and the cartridge seat.

A particularly important aspect of the invention is that the bottom surface of the housing main body exerts a force on the sealing ring against the cartridge seat of the sanitary fitting when the valve cartridge is mounted into the sanitary fitting. By providing a housing main body with a rigid bottom surface and inner parts of the valve placed above the bottom surface, inner valve elements like e.g. valve disks are not subjected to this force. Thus, it is possible to provide a given play for the valve elements within the housing main body independent from a mounting force exerted on the housing main body which consequently acts on the sealing ring between the bottom surface of the housing main body and the cartridge seat of the sanitary fitting.

In order to provide sufficient travel distance for the sealing confiner element, the sealing ring may have a substantially rectangular cross section such that the sealing ring looks like a closed ribbon. The longer side of the rectangular cross section then defines the height of the sealing ring. This height may be set in the range from approximately <NUM> to <NUM>, preferably from approximately <NUM> to <NUM>, in particular approximately <NUM>.

The sealing confiner element surrounds the sealing ring in a direction transverse to the longitudinal axis and thereby in particular prevents an outward radial movement of the sealing ring. For this purpose, the sealing confiner element preferably fully surrounds the bottom sealing. However, e.g. in case of several sealing rings in a sealing unit the sealing rings may support each other such that the sealing confiner element is only necessary to prevent outward movements of the outer ring parts.

The sealing confiner element may be substantially formed as a disk having one or more through holes which surround the sealing ring respectively each of the sealing rings.

Preferably however, the sealing confiner element comprises a sleeve part extending longitudinally which transversely confines the sealing ring.

A sleeve part allows more flexibility for the shape of the sealing confiner element. In particular the sealing confiner element may comprise a flat bottom surface from which the sleeve part protrudes towards the housing main body.

Preferably, the housing main body comprises a sealing support ridge protruding longitudinally from a bottom surface of the housing main body, wherein the sealing ring rests on the sealing support ridge and wherein the sealing confiner element longitudinally extends along the sealing ring and at least partially along the sealing support ridge.

This allows that the sealing confiner element or in particular any sleeve part of the sealing confiner element may telescopically slide next to the sealing support ridge when the sealing ring is compressed and the axial gap narrows.

The sealing support ridge may have the same ring shape as the sealing ring and may likewise surround the water connection opening. In particular, the sealing support ridge may comprise a rip having a rectangular cross-section shape.

Alternatively or additionally, the bottom surface of the housing main body could comprise a slit next to the position where the sealing ring rests. The sleeve part of the sealing confiner element could then dip into this slit and thereby restricting any transversal movements of the sealing ring.

Preferably, the housing main body comprises a sleeve part which at least partially surrounds a part, in particular the sleeve part, of the sealing confiner element.

This allows the housing main body to counter-act on the sealing confiner element from the outside which results in absorbing at least a part of the forces involved with a pressure hammer. Thereby the stability is increased and/or the sealing confiner element may be designed with thinner walls.

Preferably, the valve cartridge comprises a biasing mechanism which biases the sealing confiner element away from the housing main body.

This ensures that the varying gap is always bridged by the sealing confiner element independent of the gap height, because the sealing confiner element is biased towards its maximum protruding position. Such a biasing mechanism may for example be implemented by using a small spring which pushes the sealing confiner element away. Alternatively, the sealing confiner element may comprise a small spring tongue providing the biasing force.

Preferably, the valve cartridge comprises at least two water connection openings and a further sealing ring such that the two sealing rings are connected together via an elastic joint and integrally form a sealing unit, and in that the sealing confiner element is configured to at least partially surround each of the two sealing rings.

This facilitates the handling of the valve cartridge, because the sealing unit (also called bottom sealing) may be mounted and/or exchanged in one piece. Accordingly, the sealing confiner element preferably is a one-piece structure which confines all of the sealing rings for all of the water connection openings.

Preferably, the biasing mechanism includes the elastic joint to which a part of the sealing confiner element abuts such that the elastic joint biases the sealing confiner element away from the housing main body.

The elastic joints can provide the necessary biasing force and are already present because of the elastic nature of the sealing material. Therefore, no further spring elements are necessary.

Preferably, the biasing mechanism includes the sealing ring having a radial protruding shoulder and the sealing confiner element having a projection which rests on the shoulder of the sealing ring such that the sealing confiner element is biased away from the housing main body.

This is another approach to make use of the elastic nature of the sealing material in order to provide a biasing mechanism. When the sealing ring is compressed during fastening of the cartridge, the shoulder of the sealing ring retracts and the sealing confiner element may move towards the housing main body. Otherwise the shoulder of the sealing ring pushes against the projection of the sealing confiner element. Preferably, the shoulder of the sealing ring is located on the sealing ring centrally along the longitudinal direction.

Preferably, the housing main body and/or the sealing confiner element comprises a snap structure, which allows to snap the sealing confiner element in a movable but captive manner to the housing main body.

This allows any easy assembly of the valve cartridge. First the bottom sealing is placed against the housing main body of the valve cartridge. Second the sealing confiner element is snapped on the housing main body. Preferably, the sealing confiner elements also retains the sealing ring, in particular the whole sealing unit, on the housing main body, e.g. by overlapping any lugs or joints between two or more sealing rings.

Preferably, the housing main body and/or the sealing confiner element comprises a guiding structure, which is configured to guide the sealing confiner element movement along the longitudinal axis.

This prevents that the sealing confiner element entangles itself because of an inclined movement.

Preferably, the guiding structure comprises a guide pin formed on the housing main body and a corresponding guide hole formed on the sealing confiner element.

Such a guide pin may at the same time be used as an alignment means for the valve cartridge with respect to the cartridge seat of the sanitary fitting.

With respect to the sanitary fitting the object of the invention is achieved by a sanitary fitting comprising a cartridge seat and a valve cartridge as discussed above which may be fluid tightly sealed to the cartridge seat.

Various features and advantages of the present invention may be more readily understood with reference to the following detailed description taken in conjunction with the accompanying drawings in which:.

<FIG> shows a sanitary fitting <NUM> which uses a valve cartridge <NUM> for realizing the actual valve function of the sanitary fitting <NUM>, in this case a single lever mixing valve.

The sanitary fitting <NUM> comprises a housing <NUM> and a connection body <NUM> which on the one hand is connected with hot and cold water supply lines <NUM>. On the other hand the connection body <NUM> defines a cartridge seat <NUM>, which comprises seat water connection openings <NUM>. As shown in this embodiment, the valve cartridge <NUM> is then arranged on top of the cartridge seat <NUM>. However, in general the orientation and positioning of the cartridge seat <NUM> and the valve cartridge <NUM> depends on the overall shape of the sanitary fitting <NUM>.

In <FIG> shown above the valve cartridge <NUM>, a fastening ring <NUM> is arranged for pressing the valve cartridge <NUM> against the cartridge seat <NUM>.

For the purpose of a fluid tight connection between the valve cartridge <NUM> and the cartridge seat <NUM> a sealing, in particular an axial bottom sealing <NUM>, is arranged intermediate these two components.

The marked distances x, y and z refer to main sources of manufacturing tolerances which influence the axial gap between the valve cartridge <NUM> and the cartridge seat <NUM>.

The details of the valve cartridge <NUM> can be seen from <FIG> and <FIG>.

The valve cartridge <NUM> comprises a housing main body <NUM> which has a longitudinal axis <NUM> thereby axially defining a top side to a bottom side of the valve cartridge <NUM>. Furthermore, the exemplary single lever mixing cartridge comprises a lever spindle <NUM>, protruding from the top side of the housing main body <NUM> which is used to control the opening and mixing setting of the valve cartridge <NUM>.

On its bottom side the valve cartridge <NUM> comprises in this embodiment three water connection openings <NUM>, wherein two of the three water connection openings <NUM> are inlets for hot and cold water and the respective third water connection opening <NUM> is the mixed water outlet. The water connection openings <NUM> are arranged such that each one aligns with one of the corresponding seat water connection openings <NUM> of the cartridge seat <NUM> in the sanitary fitting <NUM>.

In order to properly align the valve cartridge <NUM> with respect to the cartridge seat <NUM>, the housing base body <NUM> of this embodiment comprises a positioning pin <NUM> as an example of an alignment means protruding from the bottom side of the valve cartridge <NUM>. The cartridge seat <NUM> comprises a corresponding which is arranged off center, in particular near the circumference of valve cartridge <NUM>. The off centered arrangement allows to counter-act any torque forces caused during fastening of the fastening ring <NUM>.

The bottom sealing <NUM> comprises three sealing rings <NUM> for each of the water connections openings <NUM>. The sealing rings <NUM>, which each have the shape of a ribbon bend to an oval or kidney-shaped ring are interconnected to each other via elastic joints <NUM>.

The bottom sealing <NUM> rests on three sealing support ridges <NUM> which protrude from a bottom surface <NUM> of the housing main body <NUM>.

Finally, the valve cartridge <NUM> comprises a sealing confiner element <NUM> which is substantially disc shaped with a seat side <NUM> pointing towards the cartridge seat <NUM> of the sanitary fitting.

The sealing confiner element <NUM> further comprises three through holes <NUM> surrounding the shape of each of the sealing rings <NUM> when the sealing confiner element <NUM> is attached to the housing main body <NUM>.

Each through hole <NUM> has a sidewall <NUM> which surrounds its corresponding sealing ring <NUM>. The sidewall <NUM> thereby acts as a sleeve which restricts transversal movement of the sealing ring <NUM>.

The sealing confiner element <NUM> further comprises a snap lug <NUM> comprising a longitudinally elongated opening which cooperates with a snap projection <NUM> on the housing main body <NUM> such that the sealing confiner element <NUM> is captively attached to housing main body <NUM> (which means that it cannot detach without dedicated action by the user).

However, because of the elongated opening the sealing confiner element <NUM> may still move slightly along the longitudinal axis with respect to the housing main body <NUM>.

Nonetheless, the retracting movement of the sealing confiner element <NUM> towards the housing main body <NUM> is hindered by the elastic joints <NUM> to which the sidewalls <NUM> abut. This elastic joints <NUM> bias the sealing confiner element <NUM> away from the bottom surface <NUM> of the housing main body <NUM>.

The valve cartridge <NUM> works as follows:
When the valve cartridge <NUM> is fastened against the cartridge seat <NUM> of the sanitary fitting <NUM>, the sealing rings <NUM> get compressed and an axial gap between the bottom surface <NUM> of the housing main body <NUM> and the cartridge seat <NUM> decreases. As soon as the gap height is small enough that the seat side <NUM> of the sealing confiner element <NUM> abuts against the cartridge seat <NUM>, the sealing confiner element <NUM> and the housing main body <NUM> move further and further together.

This movement is possible because the sidewalls <NUM> may slide into the clearance next to the protruding sealing support ridges <NUM> on the bottom surface <NUM> of the housing main body <NUM>.

When the valve cartridge <NUM> is finally fastened, the sealing confiner element <NUM> prevents transversal movements, in particular radially outward movements, of the sealing rings <NUM>, because the sealing rings <NUM> abut against the sidewalls <NUM> over the hole longitudinal height of the sealing rings <NUM>.

<FIG> and <FIG> show a second embodiment of the valve cartridge <NUM>, wherein structurally or functionally identical or similar elements are referred to by the same reference numbers as before.

The valve cartridge <NUM> of this second embodiment differs mainly in one aspect: The position pin <NUM> is placed even further radially outwards and therefore does not have a circular form anymore.

Furthermore, the detailed view of <FIG> helps to better understand how the elastic joints <NUM> bias the sealing confiner element <NUM> towards its maximum protruding position.

<FIG> and <FIG> show a third embodiment of the valve cartridge <NUM>, wherein again structurally or functionally identical or similar elements are referred to by the same reference numbers as before.

As can be seen from the detailed view in <FIG>, sealing ring <NUM> comprise a shoulder <NUM> on which a projecting collar <NUM> around the through holes <NUM> of the sealing confiner element <NUM> rests. In this case, the sealing confiner element <NUM> is biased directly by the sealing ring <NUM>, because the shoulder <NUM> of the sealing ring <NUM> now provides the biasing force.

Furthermore, the housing main body <NUM> comprises an outer circumferential sleeve <NUM> which at least partially surrounds the sealing confiner element <NUM>. Thereby a sleeve part <NUM> of the sealing confiner element <NUM> which forms the sidewall <NUM> may - with its outer side - lean against the outer circumferential sleeve <NUM> of the housing main body <NUM>. This strengthens the overall design of the valve cartridge <NUM>.

Claim 1:
A valve cartridge (<NUM>) for a sanitary fitting (<NUM>) having
a) a housing main body (<NUM>), which has a longitudinal axis (<NUM>) and comprises at least one water connection opening (<NUM>) at a bottom surface (<NUM>), and
b) a sealing ring (<NUM>) for fluid tight sealing of the at least one water connection opening (<NUM>) against a cartridge seat (<NUM>) of the sanitary fitting (<NUM>), wherein
c) the valve cartridge (<NUM>) comprises a sealing confiner element (<NUM>), which is movable relative to the housing main body (<NUM>) along the longitudinal axis (<NUM>) of the housing main body (<NUM>) and which at least partially surrounds the sealing ring (<NUM>) such that a transverse movement of the sealing ring (<NUM>) is restricted,
characterized in that
the sealing ring (<NUM>) rests on the bottom surface (<NUM>) of the housing main body (<NUM>).