Patent Description:
An exterior tap is typically mounted at an outside wall of a building, e.g. to provide a water supply to the garden. As the tap is clearly visible, it may interfere with the sleek appearance of a façade, e.g. a façade in white plaster. In the prior art, taps with a minimalistic appearance are found, but they lack a number of specific technical features, making them unsuitable for outside use.

Indeed, specific technical measures are required due to the fact that a hose may be connected to an exterior tap. As the hose may be lying on the ground or have its end in an outside reservoir, a risk exists that polluted water flows back towards the supply side, thereby contaminating the potable water supply. Two situations exist in which such a backflow may be triggered.

In a first situation, water pressure in the supply pipe may fail or be reduced, e.g. when a water main bursts. Reduced pressure in the pipe may allow contaminated water from the soil, from storage, or from other sources to be drawn up into the drinking water system. In order to prevent such a backflow, the use of an anti-siphon device, also referred to as backflow preventer or atmospheric vacuum breaker, is required for an outside tap. An anti-siphon device works by allowing air to enter the water system if an upstream pressure drop occurs. Inside is a small valve that allows the water to flow when a normal water pressure is found in the system, while closing the air entrance to the device. If the pressure in the upstream side is reduced to atmospheric pressure or below, the valve changes position and allows air to enter the system, breaking the siphon.

In a second situation, a risk of contaminated water flowing back arises when the downstream pressure is raised, e.g. due to connecting a high-pressure cleaner. In order to protect potable water supplies from contamination, often a non-return valve or check valve is used within the tap. The non-return valve opens due to an upstream water pressure, but blocks a backflow following an increased downstream pressure.

Many taps having a minimalistic appearance are designed for inside use or do not allow to connect a hose. Therefore, they are not equipped with the required safety measures as described above. On the other hand, solutions are known in the prior art providing the required safety measures, but not having the desired sleek design.

For example, a hose-bibb vacuum breaker is a screw-on type anti-siphon device having circumferentially positioned vents to allow air to enter the system when an upstream pressure drop occurs. Also in a classical exterior tap, e.g. shown at https://buks-vedder. de/shop/sanitaer/auslaufventile/<NUM>/auslaufventil-<NUM>/<NUM>-mit-rohrbeluefter-rueckflussverhinderer-dvgw, often such circumferentially positioned vents are visible in the outlet part of the tap. However, in order to allow a sufficient air supply towards those vents, a significant gap between the outlet housing and the hose connector is present in axial direction. This results in a lack of alignment in axial direction, therefore not allowing for a sleek appearance of the tap.

Examples of a screw-on type anti-siphon device are found in <CIT> and <CIT>. Both present an anti-siphon device that may be screwed on the outlet of a tap. In <CIT>, the circumferentially positioned vents are mostly shielded by the surrounding housing of the anti-siphon device. Therefore, in order to allow a sufficient air supply towards the vents, a significant gap between the housing of the anti-siphon device and the hose connector must be present in axial direction, thereby not allowing for a sleek appearance of the tap. In <CIT>, an embodiment is presented wherein a union nut is used to attach an anti-siphon device to a tap outlet. The union nut carries the housing of the anti-siphon device, and is screwed onto an external thread of the tap outlet. As the radial ventilation openings of the anti-siphon device are shielded by the union nut, the union nut comprises at least one bore, allowing air to reach the radial ventilation openings. The union nut is an additional component, mounted externally onto the tap outlet, thereby disrupting the appearance of the tap outlet. Moreover, a substantial axial gap is present between the outlet of the tap and a mounted hose connector, thereby not allowing for a sleek appearance. Finally, the one or more bores in the union are visible to the user, thereby further disrupting the appearance of the tap.

Another solution is found in <CIT>. A wall hydrant is presented having a check valve to prevent backflow caused by excessive water pressure at the outlet port. Moreover, a vacuum breaker is used to prevent undesirable back siphonage backflow. The vacuum breaker is located on top of the faucet, exterior to the faucet housing. It is therefore clearly visible and does not allow for a sleek appearance of the faucet.

In <CIT> and <CIT> frost-proof drain fitting for an outside tap is described. Similar to the previous solution, the tap is equipped with two safety measures. Firstly, an aerator is used acting as an anti-siphon device. As in the previous solution, the aerator is positioned on top of the tap, thereby not allowing for a sleek design of the tap. Secondly, a non-return cone is used that only opens at sufficient system pressure in the piping system, and prevents a backflow due to an increased downstream pressure. Moreover, additional protection is obtained by means of a backflow preventer integrated within the tap outlet. When a backflow against the normal flow direction originates from a connected hose, the backflow preventer blocks passage towards the inside of the tap, and the polluted water is drained by means of a backflow outlet hole provided in the outlet housing.

Contrary to the aforementioned solutions of <CIT>, <CIT> and <CIT>, where the exterior position of the anti-siphon device prevents a sleek appearance of the tap, in <CIT> a solution is presented to conceal an anti-siphon device within the faucet. For this purpose, an anti-siphon breaker valve is integrated within a hollow ball valve. The upper part of the ball valve comprises vent apertures, being in communication with an auxiliary opening in the tap housing, the auxiliary opening being in connection with outside air. In case of an upstream pressure drop, an anti-siphon air passageway is formed through the auxiliary opening, the vent apertures and the interior of the ball valve, thereby changing the position of the anti-siphon breaker valve and preventing a siphonage backflow. Although the solution of <CIT> allows to conceal the anti-siphon device, the appearance of the faucet is not minimalistic. Moreover, the solution requires custom features, like the use of a hollow ball valve and the provision of an auxiliary opening at the position where the control stem enters the housing. Therefore, the described concept to conceal the anti-siphon device cannot generally be applied to another tap having a completely other design.

It is an objective of the present invention to disclose an exterior tap, that resolves one or more of the above described shortcomings of the prior art solutions. More particularly, it is an objective to present an exterior tap that allows for a minimalistic appearance, while integrating backflow preventing safety measures.

According to the present invention, the above identified objectives are realized by a tap for providing an exterior water supply defined by claim <NUM>, the tap comprising:.

Thus, the invention concerns a tap for providing an exterior water supply. An exterior tap is typically mounted at an outside wall of a building, e.g. to provide a water supply to the garden. Typically, a hose may be connected to the tap, possibly after mounting a connector part to the tap.

The tap comprises an outlet part. An outlet part is defined as a part of the tap having two ends. When the tap is opened by means of an operating handle, the first end receives a water flow from the supply pipe, and at the other end the water flows out towards the environment or a connected hose. When the tap is closed by means of the operating handle, no water flows through the outlet part. The outlet part comprises an intake port adapted to receive a water flow when the tap is open, and comprises one or more flow channels adapted to guide the water flow towards the outlet side of the tap.

The tap further comprises an anti-siphon device. The anti-siphon device is comprised in the outlet part. This implies that the position of the anti-siphon device is close to the outlet of the tap, and is not positioned for example on top of the tap. For example, when a tap comprises a horizontal supply part and a downwardly pointing outlet part, the anti-siphon device is located within the downwardly pointing outlet part, and not on top of the horizontal supply part. In other words, the anti-siphon device is not positioned exterior to the tap housing, but is integrated within the outlet part.

The anti-siphon device is adapted to prevent a backflow of polluted water when a pressure drop occurs at the upstream side, e.g. due to a pipe burst. For this purpose, the anti-siphon device comprises vents and a valve. The vents are openings adapted to let outside air enter into the interior of the anti-siphon device. The vents are circumferentially positioned, which means that across the circumference of the anti-siphon device such vents are present. For example, in an embodiment, the anti-siphon device may have a cylindrical outer surface, and the vents may be positioned at a circular line. At least two vents are present. For example, in an embodiment two vents may be positioned opposite to each other. In another embodiment, a series of vents may be available, e.g. positioned equidistantly across the circumference of the anti-siphon device.

The valve of the anti-siphon device is movable between a first and a second position. In the first position the intake port is opened and the vents are sealed from the flow channels. Under normal flow conditions, i.e. at normal upstream water pressure, the valve is in the first position, thereby allowing water to flow from the intake port through the flow channels. At the same time, the outside air entering the anti-siphon device by means of the vents is blocked from flowing towards the flow channels or towards the supply side. When the valve is in the second position, the intake port is closed, and a passageway is formed between the vents and the flow channels. The valve moves towards the second position when an upstream pressure drop occurs. For example, the valve is moved towards the second position due to the pressure difference between a negative pressure at the supply side of the valve and an atmospheric pressure at the outlet side of the valve. In the second position of the valve, a connection is formed between the vents and the flow channels, while the connection between the supply side and the flow channels is blocked by the valve. In this way, outside air entering the anti-siphon device by means of the vents may flow towards the flow channels and possibly may be leaking somewhat towards the supply side due to negative upstream pressure and the valve not perfectly closing the intake port. In this way, the upstream pressure drop does not result in polluted water flowing back, and at most some air is drawn by the supply system. In possible embodiments, the valve may be held in the first position when the tap is closed. In other embodiments, the valve may be in the second position for a closed tap.

The outlet part further comprises a sleeve mounted around the anti-siphon device, such that a circumferential slit is present between the sleeve and the anti-siphon device. In an embodiment, the sleeve may be part of the housing of the tap. The sleeve is mounted around the anti-siphon device, which implies that the anti-siphon device is entirely or partly concealed by the sleeve mounted around it. For example, the sleeve has a hollow body, and the anti-siphon device is located fully or partly within a cavity of the sleeve. The sleeve is mounted such that a slit is present between the sleeve and the anti-siphon device, along the circumference. This implies that, across its entire height or part of its height, the sleeve is not in contact with the anti-siphon device, but some space is present in between, e.g. in radial direction.

Moreover, the sleeve comprises a recess, such that an air passageway is present from the exterior environment to the vents via the recess and the circumferential slit. A recess may e.g. be an opening in the surface of the sleeve. The recess allows air to enter from the outside environment towards the circumferential slit. Furthermore, air present in the circumferential slit may continue its way through the vents towards the interior of the anti-siphon device. Because of the presence of the circumferential slit, no direct alignment is needed between the recess and a vent of the anti-siphon device.

The invention is advantageous compared to solutions known in the prior art, because of various aspects. Firstly, an anti-siphon device is present, while still allowing for a minimalistic design of the tap. This means that the required protection against contamination due to back siphonage is provided, but the presence of the anti-siphon device does not interfere with the outside appearance of the tap. Indeed, the fact that the anti-siphon device is integrated within the outlet part of the tap, and is entirely or partly concealed by the sleeve, allows for a minimalistic appearance, contrary to solutions where the anti-siphon device is clearly visible from the outside of the tap.

Another advantage is that, despite the fact that the anti-siphon device is integrated within the outlet part, still a good performance of the anti-siphon device is obtained. Indeed, the presence of the recess in the sleeve ensures that air is provided towards the vents, even when a connector, e.g. a hose connector, is mounted very close to the sleeve. As such, no substantial axial gap is required between the sleeve and a connector, contrary to a hose-bibb vacuum breaker or classical exterior tap where such an axial gap is required to provide air towards the circumferentially positioned vents. Consequently, the presence of the recess in the housing allows for a nice alignment of the sleeve and a mounted connector, leading to a sleek appearance of the tap.

Furthermore, the circumferential slit between the sleeve and anti-siphon device allows that air can be optimally supplied towards all the circumferentially positioned vents. Indeed, the presence of the circumferential slit allows sufficient air to enter in an equally distributed way, thereby moving the valve promptly in a balanced way when siphonage conditions occur. An optimal supply of air results in an optimal performance of the anti-siphon device, as it is the provided air that triggers the movement of the valve and that dissolves the occurring negative pressure. The latter is important to prevent that a backflow is actually triggered. As the anti-siphon device is comprised in the outlet part, the negative pressure is dissolved close to the outlet side, thereby preventing that polluted water is sucked into the tap.

Finally, due to the presence of the circumferential slit, it is allowed that none of the vents is perfectly positioned opposite to the recess in the sleeve. This has the advantage that an optimal performance of the anti-siphon device is obtained, while allowing for a simple and fast assembly of the tap.

The sleeve comprises a wall with varying thickness. For example, the sleeve is a hollow body surrounded by a wall having a certain thickness. This thickness is not constant, but varies along the height of the sleeve, where the height is defined as the dimension following the central axis of the outlet part. Having a wall with varying thickness has the advantage that a circumferential slit between the sleeve and the anti-siphon device may easily be created. For example, in an embodiment, the sleeve may be mounted such that one part is in contact with the anti-siphon device, while another part, having a smaller thickness, is not in contact with the anti-siphon device but some space is left between the sleeve and the anti-siphon device. In this way, the anti-siphon device can easily be fixed to the sleeve, e.g. by means of screwing, while at the position of the vents, the circumferential slit allows for an optimal air supply towards the vents.

The wall of the sleeve comprises multiple parts with different thicknesses and/or the thickness of the wall varies in a continuous way. This implies that the varying thickness of the sleeve wall may be obtained in different ways. In an embodiment, the sleeve comprises multiple parts, where not all parts have the same thickness. For example, the circumferential slit is created between a thinner part of the sleeve and the anti-siphon device, while a thicker part of the sleeve is in contact with the anti-siphon device. In another embodiment, the wall thickness varies in a continuous way, as is e.g. the case when the sleeve has a conical inner surface. In yet another embodiment, a combination of multiple parts with different thicknesses and a continuously varying thickness is used for the sleeve wall.

The wall comprises a cylindrical outer surface, an upper wall part with a first thickness, and a lower wall part with a second thickness, wherein the second thickness is smaller than the first thickness. In an embodiment, the cylindrical outer surface of the sleeve may align with a cylindrical outer surface of a mounted connector, e.g. a hose connector. Therefore, the cylindrical outer surface of the sleeve has the advantage that a flat outer surface of the outlet part may be created, thereby contributing to a sleek appearance of the tap. Moreover, at the interior of the sleeve, a smaller inner diameter may be used for a first part and a larger inner diameter may be used for a second part of the sleeve. In this way, the sleeve comprises an upper wall part with a higher thickness, and a lower wall part with a smaller thickness. By mounting the sleeve around the anti-siphon device, automatically a circumferential slit is created between the sleeve and the anti-siphon device at the position of the lower wall part. This has the advantage that the sleeve is a simple and easily producible part, while an optimal air supply towards the vents is established.

The outlet part comprises a connecter, the connector comprising a cylindrical part, such that in mounted condition the outer surface of the cylindrical part is aligned with the cylindrical outer surface of the wall of the sleeve. A connector is a part that may be mounted to the tap, e.g. by screwing or clicking. For example, it may be a hose connector, comprising an end that allows to connect a hose. In another embodiment, the connector may be a fitting, a spout, etc. The connector has a cylindrical part, located at the side where the connector is mounted to the tap. In mounted condition, the outer surface of the cylindrical part of the connector aligns with the cylindrical outer surface of the sleeve. This means that both outer surfaces are in line with each other, thereby defining a continuous cylindrical surface. This contributes to a sleek and minimalistic appearance of the tap.

In mounted condition the cylindrical part of the connector and the sleeve are positioned close to each other, leaving an intermediate axial gap of less than <NUM>, preferably less than <NUM>. The axial direction is defined as the direction of the central axis of the outlet part. In axial direction, the connector is positioned very close to the sleeve, such that the connector is almost in contact with the sleeve. Only a gap of less than <NUM>, preferably less than <NUM> is left between the mounted connector and the sleeve in axial direction. In this way, the anti-siphon device is almost completely concealed by the sleeve and connector. Moreover, the small axial gap is almost invisible for the user, who merely perceives a continuous cylindrical surface defined by the sleeve and connector. The invisibility of both the anti-siphon device and the axial gap contribute to a sleek and minimalistic appearance of the tap.

Optionally, as is indicated by claim <NUM>, the anti-siphon device comprises screw thread adapted to mount the connector close to the sleeve, leaving an axial gap of less than <NUM>, preferably less than <NUM>, between the sleeve and connector. This implies that the anti-siphon device comprises a part provided with screw thread, this part e.g. being located underneath the part with circumferentially positioned vents. Therefore, the connector can be mounted by screwing it onto the anti-siphon device. This has the advantage that a minimal number of components is needed for assembly, the connector can easily be mounted and removed, and the mounting of the connector automatically results in the small axial gap between the connector and the sleeve.

Optionally, as is indicated by claim <NUM>, the recess is a hole in the wall of the sleeve, positioned at the bottom side of the cylindrical outer surface of the sleeve, such that in mounted condition the recess is in contact with the axial gap and is positioned at the back side of the tap. For example, in an embodiment, the sleeve may comprise a lower wall part with smallest thickness, and the recess may be an opening extending over the height of that lower wall part. This implies that air flowing through the recess, directly enters into the circumferential slit, thereby contributing to an optimal air supply towards the vents of the anti-siphon device. Furthermore, in mounted condition the recess is positioned at the back side of the tap. The back side of the tap is defined as the side of the tap which, after mounting the tap to an exterior building wall, is directed towards the building wall. Thus, the back side of the tap is the side being the least visible for the user of the tap. Therefore, positioning the recess at the back side has the advantage that the recess does not or only partly interferes with the sleek front view of the tap, being visible for the user in daily use. Moreover, in an embodiment, the width of the recess may be chosen such that the recess is invisible or almost invisible from a side view, thereby contributing even more to the sleek appearance of the tap.

Optionally, as is indicated by claim <NUM>, the dimensions of the recess are such that the surface area of the opening defined by the recess is at least <NUM>,<NUM> times, preferably at least <NUM> time, the joint surface area of the openings defined by the vents. This implies that the area of the recess is chosen large enough, in order to allow a sufficient air flow towards the vents. In other words, even if no axial gap between the sleeve and connector would be present, air may flow towards the vents just like in a prior art solution where the vents are in direct contact with the outside air. This contributes to an optimal functioning of the anti-siphon device, even when the sleeve and connector are very closely positioned. In an embodiment, the shape of the recess may be chosen such that the sufficient area as mentioned above is obtained, but at the same time the width is chosen small enough, making the recess invisible or almost invisible from a side view. This further contributes to a sleek appearance of the tap.

Optionally, as is indicated by claim <NUM>, the tap comprises an inlet housing connected to the sleeve, the inlet housing comprising a cylindrical outer surface with axis perpendicular to the axis of the cylindrical outer surface of the sleeve. The inlet housing typically covers the supply pipe of the tap or part thereof. The inlet housing and the sleeve together form a housing of the tap, which is T-shaped. Both the horizontal part of the T-shape and the vertical part of the T-shape have a cylindrical surface, contributing to a sleek appearance. As the inlet housing has a cylindrical outer surface, no other parts, like e.g. an anti-siphon device, are mounted on top of the inlet housing, preventing that the flat outer view would be disturbed.

Further optionally, as indicated by claim <NUM>, the inlet housing comprises a groove positioned in a transversal contact surface. A transversal surface of the inlet housing is a surface being substantially perpendicular to the axial central axis of the cylindrical inlet housing. When mounted to an exterior building wall, such a transversal contact surface is positioned substantially parallel with the height direction of the building wall. The transversal contact surface comprises a groove, e.g. being a circular groove around the central axis of the inlet housing. The presence of a groove has the advantage that space is created to conceal a sealing material. Such a sealing material, e.g. tape or cord of teflon or hemp, is typically used to seal the screw thread of the inlet housing when the latter is mounted within a flange on the building wall. This further contributes to a sleek and minimalistic appearance of the tap, when mounted onto a building wall. Moreover, it contributes to an improved ease of installation.

Optionally, as is indicated by claim <NUM>, the anti-siphon device comprises an inner hexagon adapted to mount the anti-siphon device. In prior art solutions, often an outer hexagon, e.g. a hexagonal nut, is provided for mounting the anti-siphon device. However, such an outer hexagon interferes with a minimalistic design of the tap. To the contrary, using an inner hexagon means that the anti-siphon device comprises a hollow part with hexagonal interior. The later allows to mount the anti-siphon device in the sleeve using a tool with hexagonal outer contour. Providing an inner hexagon has the advantage that the anti-siphon device can easily be mounted, while the hexagon is not visible from the outside. This contributes to a sleek and minimalistic appearance of the tap.

Optionally, as is indicated by claim <NUM>, the anti-siphon device comprises a cylindrical body. The cylindrical body comprises radial channels extending between the circumferentially positioned vents and a central space within the body. This implies that the anti-siphon device has a cylindrical outer surface, and channels run in radial direction from the vents at the outer surface towards a central space within the anti-siphon device. The central space has a closed end and an open end, where in mounted condition the open end is at the side of the intake port. Moreover, the anti-siphon device comprises axial channels, being comprised in the flow channels. Axial channels are channels in the direction of the central axis of the outlet part of the tap. The axial channels are adapted to receive a water flow and guide the water towards the outlet.

Furthermore, the valve is adapted to close the open end of the central space when the valve is in its first position. This implies that air flowing through the vents and radial channels, enters the central space, but is further blocked by the valve. Therefore, at normal flow conditions the vents are sealed from the flow channels, and water flows through the axial channels when the tap is open.

Moreover, the valve is adapted to open the open end of the central space in the second position of the valve, such that an air passageway is formed between the central space and the axial channels. Thus, when the valve is in its second position, the open end of the central space remains open, and the axial channels are in communication with the central space of the anti-siphon device such that air may leave the central space towards the flow channels. This prevents that a backflow of polluted water is triggered in case an upstream pressure drop occurs.

Typically, the valve is held in the first position under its own weight and/or the pressure of a supplied water flow, and the valve is moved to the second position through a pressure difference between atmospheric air pressure within the central space and a negative pressure at the position of the intake port. In an embodiment, the valve may be in the first position when the tap is closed, remain in the first position when the tap is open and normal flow conditions occur, and move to the second position under back siphonage conditions. In another embodiment, the valve may be in the second position when the tap is closed, may move to the first position when the tap is open due to the pressure of the supplied water flow, and may move to the second position under back siphonage conditions. The valve moving to the second position is triggered by a pressure difference at both sides of the valve. If a negative pressure arises at the upstream side of the valve, e.g. due to a pipe burst, the valve is pushed to the second position by the air at atmospheric pressure present within the central space of the anti-siphon device.

Optionally, as is indicated by claim <NUM>, the tap comprises an operating handle and a non-return valve connected to said operating handle, the non-return valve being positioned within the inlet housing and being adapted to directly control the water supply to the intake port of the outlet part. An operating handle is a component allowing to open and close the tap, like e.g. a rotary control, dial, lever or button. The operating handle is connected to a non-return valve. This implies that when opening a closed the tap, the non-return valve is changed in position, such that water may start to flow. The valve is a non-return valve, which means that it is adapted to open under the pressure of a flow in one direction, e.g. by compressing a spring, but blocks a flow in the opposite direction. The presence of a non-return valve has the advantage that a backflow of water is blocked, thereby preventing that any polluted water flows into the supply pipe. Such a backflow may be triggered by a downstream pressure increase, e.g. due to connecting a high-pressure cleaner. The non-return valve is positioned within the inlet housing and is adapted to directly control the water supply to the intake port of the outlet part. This implies that the non-return valve is located within the inlet housing, but at a position close to the intake port of the outlet part. This results in a compact design, where nearby the intake port both the opening/closing of the tap and the blocking of a high-pressure backflow is controlled. Such a compact design contributes to a minimalistic appearance of the tap, where especially the operating handle may have a small size. For example, in an embodiment, the operating handle may be a cylindrical rotary button aligned with the cylindrical outer surface of the inlet housing, the length of the button in axial direction being small due to the compact design of the internally connected non-return valve.

Optionally, as is indicated by claim <NUM>, the operating handle comprises a cover element and a rotating element, the cover element being adapted to cover a transverse surface of the rotating element, and the cover element comprising a screw adapted to connect the cover element to the rotating element. The rotating element is typically the part which is rotated by the user to open or close the tap. In mounted condition, a cover element is connected to the rotating element, being located at the front end of the tap. The cover element thereby covers the front part of the rotating element. The cover element comprises a screw. This implies that the screw forms a single entity with the rest of the cover element. In other words, no individual screw is used, but the screw is integrated within the cover element. This has the advantage that enough screw thread may be provided to allow for a qualitative connection, but at the same time the cover element may be thin and the operating handle may be short in length. This further contributes to a sleek and minimalistic appearance of the tap.

Optionally, as is indicated by claim <NUM>, the rotating element comprises a circumferentially positioned collar, the collar being adapted to cover an internally positioned slit ring. A slit ring is typically made of an elastic material and is typically used to avoid a metal-to-metal contact when rotating the operating handle. A slit ring may be positioned between the rotating element and the non-moving inlet housing, thereby providing for a fluent and durable rotation of the operating handle. Furthermore, the rotating element comprises a collar, e.g. a protrusion along the circular edge of the rotating element. When a slit ring is positioned between the rotating element and the inlet housing, the collar allows to conceal the slit ring. This further contributes to a sleek appearance of the tap.

<FIG> shows an embodiment of an exterior tap <NUM>. Two different three-dimensional views are given. The tap <NUM> comprises a cylindrical inlet housing <NUM> and screw thread <NUM>. The screw thread <NUM> is adapted to mount the tap <NUM> in a wall mounted flange <NUM>, as is shown in <FIG>. The wall mounted flange is typically fixed within a hole of a wall, for example by means of a fastener described in <CIT>. The tap <NUM> further comprises an operating handle <NUM>, adapted to open and close the tap <NUM>. In the embodiment of <FIG>, the operating handle <NUM> is a cylindrical rotary button, of which the position is aligned with the cylindrical inlet housing <NUM>.

The tap <NUM> comprises an outlet part <NUM>. In the embodiment of <FIG>, the central axis of the outlet part <NUM> is perpendicular to the central axis of the inlet housing <NUM>. The outlet part <NUM> comprises a sleeve <NUM> and a connector <NUM>. In the embodiment of <FIG>, the connector <NUM> is a hose connector <NUM>. In other embodiments the connector may have another function, e.g. it may be a fitting, a spout, etc. In the embodiment of <FIG>, the sleeve <NUM> is fixed to the inlet housing <NUM>, e.g. they may both be produced as a single component being the housing of the tap <NUM>. The hose connector <NUM> comprises an end <NUM> adapted to connect a hose, e.g. to provide a water supply to the garden. The hose connector <NUM> further comprises a cylindrical part <NUM>, located at the side where the hose connector <NUM> is mounted to the tap <NUM>. In mounted condition, the outer surface of the cylindrical part <NUM> aligns with the cylindrical outer surface of the sleeve <NUM>.

The axial direction is defined as the direction of the central axis of the outlet part <NUM>. Following the axial direction, a small axial gap <NUM> is present between the sleeve <NUM> and the cylindrical part <NUM> of the hose connector <NUM>. Furthermore, the sleeve <NUM> comprises a recess <NUM>. In the embodiment of <FIG>, the recess <NUM> is a hole positioned at the bottom side of the sleeve <NUM>, such that in mounted condition the recess <NUM> is in contact with the axial gap <NUM>. The recess <NUM> is positioned at the back side of the tap <NUM>.

<FIG> shows a cross-section of the tap <NUM>. The outlet part <NUM> comprises an intake port <NUM>. When the tap <NUM> is open, water flows from the supply pipe <NUM> through the intake port <NUM> into the outlet part <NUM>. The outlet part <NUM> comprises flow channels <NUM>, indicated in <FIG>, adapted to guide the water flow towards the end <NUM>. The hose connector <NUM> comprises internal ribs <NUM> adapted to break the outgoing water flow and generate a nebulized jet.

<FIG> shows that an anti-siphon device <NUM> is integrated within the outlet part <NUM>. The anti-siphon device <NUM> is adapted to prevent a backflow of water from a connected hose towards the potable water supply when an upstream pressure drop occurs, e.g. due to a pipe burst. The anti-siphon device <NUM> and its functioning are further illustrated in <FIG>.

<FIG> gives a three-dimensional view of the anti-siphon device <NUM>. The anti-siphon device <NUM> comprises a cylindrical body <NUM> and a valve <NUM>. For reasons of clarity, the valve <NUM> is shown in an exploded view. The cylindrical body <NUM> comprises vents <NUM>, being positioned along the circumference of the cylindrical body <NUM>. In the embodiment of <FIG> four vents <NUM> are provided, being positioned equidistantly along the circumference. In another embodiment, another number or positioning of the vents <NUM> may be provided. The vents <NUM> allow atmospheric air to enter into a central space <NUM> within the cylindrical body <NUM>. For this purpose, the cylindrical body <NUM> comprises radial channels <NUM> extending between the vents <NUM> and the central space <NUM>, as is clear from <FIG>. The valve <NUM> comprises a cover <NUM> and an elongated part <NUM>. <FIG> show that in mounted condition of the anti-siphon device <NUM>, the elongated part <NUM> is positioned within the central space <NUM>, while the cover <NUM> is adapted to close the open top end of the central space <NUM>. <FIG> also show that an O-ring <NUM> is used for sealing.

<FIG> gives an axial cross section, following a radial direction such that the radial channels <NUM> are visible. On the other hand, the cross section of <FIG> is made along another radial direction, such that axial channels <NUM> are visible. When the anti-siphon device <NUM> is mounted into the tap <NUM> and the tap <NUM> is open, water entering through the intake port <NUM> flows through the axial channels <NUM>. The axial flow channels <NUM> are also shown on <FIG>, where a top view resp. a bottom view of the anti-siphon device <NUM> is given.

In <FIG>, the valve <NUM> is in a first position. However, the valve <NUM> is movable between a first position and a second position, as is illustrated in <FIG>. In the first position, as is illustrated in <FIG>, the intake port <NUM> is opened and the vents <NUM> are sealed from the flow channels <NUM>. In the second position, as illustrated in <FIG>, the intake port <NUM> is closed and a passageway is formed between the vents <NUM> and the flow channels <NUM>.

This is further clarified in <FIG>, where the functioning of the anti-siphon device <NUM> is illustrated in a conceptual way. <FIG> resp. show the condition of the anti-siphon device <NUM> when the tap <NUM> is closed, when normal flow conditions apply, and in a situation where an upstream pressure drop occurs. When the tap <NUM> is closed, <FIG> shows that the valve <NUM> is in the first position, where it is held under its own weight, thereby closing the central space <NUM>. In another embodiment however, the valve <NUM> may be in the second position when the tap is closed, e.g. by using a spring. In <FIG>, a water flow <NUM> enters through the intake port <NUM>. The valve <NUM> is still in its first position, such that no water may enter into the central space <NUM>. Instead, water flows through the axial flow channels <NUM>, as is indicated with the arrows <NUM>. Outside air may enter into the central space <NUM>, through the vents <NUM> and radial channels <NUM>. However, entered air cannot leave the central space <NUM>, as the valve <NUM> closes the top end of the central space <NUM>. In the situation of <FIG>, an upstream pressure drop occurs, e.g. due to a pipe burst. As an atmospheric pressure is exerted on the bottom side of the valve <NUM>, and a negative pressure at the top side of the valve <NUM>, the valve is moved towards its second position. In the second position, the intake port <NUM> is blocked by the valve <NUM>. At the same time, outside air may enter the central space <NUM>, and may leave the central space <NUM> at the open top end, see <NUM> and <NUM> in <FIG>. In this way, a connection is made between the central space <NUM> and the axial flow channels <NUM>, such that atmospheric air may fill these flow channels <NUM>. In this way, no water will be sucked from a connected hose. At most, some air is sucked towards the supply side, due to a non-perfect closing of the valve <NUM>, see the leaking flow <NUM>.

The valve <NUM> is designed such that it is movable between the first and second position under the mentioned pressure difference. For example, <FIG>show that the tap <NUM> comprises an elongated recess <NUM>, adapted to reduce the weight of the valve <NUM>.

The anti-siphon device <NUM> is integrated within the outlet part <NUM> of the tap <NUM>, as is shown in <FIG> and in <FIG> and b. <FIG> gives a detail of <FIG>, wherein the radial flow channels <NUM> are visible, similar to <FIG>, and wherein the valve <NUM> is in the first position. <FIG> gives a cross section showing the radial flow channels <NUM>, similar to <FIG>. In <FIG> the valve <NUM> is in the second position.

The sleeve <NUM> comprises a cylindrical outer surface, as is clear from <FIG>. Moreover, <FIG> show that the sleeve <NUM> comprises a wall with an upper wall part <NUM> and a lower wall part <NUM>. The figure shows that the upper wall part <NUM> has a larger thickness than the lower wall part <NUM>. In mounted condition, the upper wall part <NUM> is in contact with the anti-siphon device <NUM>, by means of the screw thread <NUM>. However, the lower wall part <NUM> is not in contact with the anti-siphon device <NUM>, due to the lower thickness of the lower wall part <NUM>. Instead, <FIG> and <FIG> show that some space is left in radial direction between the lower wall part <NUM> and the anti-siphon device <NUM>, thereby resulting in a circumferential slit <NUM>.

<FIG> shows that the sleeve <NUM> comprises a recess <NUM>. The recess <NUM> allows outside air to enter into the circumferential slit <NUM>. Thus, an air passageway is present from the exterior environment to the vents <NUM> via the recess <NUM> and the circumferential slit <NUM>. Next, an air flow may continue its way towards the internal space <NUM> of the anti-siphon device <NUM>, by means of the vents <NUM> and the radial channels <NUM>. In this way, outside air may enter the anti-siphon device <NUM> in an optimal way, resulting in an optimal performance of the anti-siphon device <NUM>. Because of the presence of the circumferential slit <NUM>, no direct alignment is needed between the recess <NUM> and a vent <NUM> of the anti-siphon device <NUM>.

<FIG> and <FIG>show that the recess <NUM> extends over the height of the lower wall part <NUM>. Moreover, the back view of the tap <NUM> given in <FIG> shows that the recess is positioned centrally, at the back side of the sleeve <NUM>. The back side is the side which, after mounting the tap <NUM> to a building wall, is directed towards the building wall. In the embodiment of <FIG>, the width <NUM> of the recess <NUM> is <NUM>,<NUM>, the height <NUM> is <NUM>,<NUM> and the radius <NUM> is <NUM>,<NUM>. These dimensions are chosen such that the surface of the recess <NUM> is about equal to the sum of the surfaces of the vents <NUM>, were each vent <NUM> has a circular surface with radius <NUM>. In this way a sufficient amount of air may flow towards the vents <NUM>, even when the axial gap <NUM> is kept very small. On the other hand, the width <NUM> of the recess <NUM> is chosen such that the recess <NUM> is almost invisible when looking at the tap <NUM> from a side view. In this way, the presence of the recess <NUM> guarantees an optimal functioning of the anti-siphon device <NUM>, while not disturbing the sleek appearance of the tap <NUM>.

In another embodiment, the circumferential slit <NUM> may be created in another way. For example, the sleeve <NUM> may have a wall with a conical inner surface. Moreover, in other embodiments, another shape or positioning of the recess <NUM> is possible.

<FIG>show that the anti-siphon device <NUM> is mounted within the sleeve <NUM>, by means of screw thread <NUM>. Moreover, the anti-siphon device <NUM> comprises an inner hexagon <NUM>, as is visible on <FIG>, <FIG>, <FIG> and <FIG>. The inner hexagon <NUM> allows to easily mount the anti-siphon device <NUM>, using a tool with hexagonal outer contour. As the hexagon is not visible from outside, it does not disturb the outer appearance of the tap, see <FIG>.

<FIG> and <FIG> further show that the anti-siphon device <NUM> comprises screw thread <NUM> adapted to mount the hose connector <NUM>. The screw thread <NUM> was not drawn on <FIG> and <FIG> and b. As is clear from <FIG>, <FIG>, <FIG> and <FIG>, in mounted condition the hose connector <NUM> is positioned very close to the sleeve <NUM>, leaving an axial gap <NUM> of less than <NUM>, preferably less than <NUM>, between the sleeve <NUM> and the cylindrical part <NUM> of the hose connector <NUM>. In the embodiment shown in <FIG>, the height <NUM> of the axial gap <NUM> is <NUM>,<NUM>. Moreover, the figures show that the cylindrical part <NUM> and the sleeve <NUM> are aligned, thereby defining a continuous cylindrical surface. The anti-siphon device <NUM> is almost completely concealed by this cylindrical surface. Only the recess <NUM> reveals a small part of the anti-siphon device <NUM>, but due to its position directed towards the building wall, it is not eye-catching. As a result, the user merely perceives a sleek cylindrical outlet part, leading to a minimalistic appearance of the tap <NUM>, see <FIG> and <FIG>. Moreover, also the inlet housing <NUM>, which has a cylindrical outer surface without any disturbances, and the cylindrical operating handle <NUM> aligned with the inlet housing <NUM>, contribute to this minimalistic appearance. Despite the minimalistic design, the necessary safety measures are provided within the tap <NUM>, due to the integrated anti-siphon device <NUM>. Finally, due to the fact that the anti-siphon device <NUM> is almost completely covered by the sleeve <NUM> and hose connector <NUM>, a chromium plating of the anti-siphon device <NUM> is not required, thereby avoiding the cost and environmental impact of such a chromium plating.

<FIG> further shows that the tap <NUM> comprises a non-return valve <NUM>. The non-return valve <NUM> is also shown in the exploded view of <FIG>. In mounted condition, the non-return valve <NUM> is connected to the operating handle <NUM>. Turning the rotary operating handle <NUM> results in a displacement of the non-return valve <NUM>, thereby opening or closing the entrance towards the intake port <NUM>. When the tap <NUM> is open, water may flow from the supply pipe <NUM> towards the outlet part <NUM> by compressing a spring <NUM>. However, the non-return valve <NUM> blocks a water flow in the opposite direction, as the spring <NUM> is not compressed. In this way, water flowing back due to an increased downstream pressure is blocked and cannot flow into the supply pipe <NUM>.

The non-return valve <NUM> is positioned within the inlet housing <NUM> and is adapted to directly control the water supply to the intake port <NUM>. The cross-section of <FIG> gives a closer view on the positioning of the non-return valve <NUM>. In particular, the non-return valve <NUM> is integrated within the inlet housing <NUM> in such a way that the distance <NUM> between the headwork seat <NUM> and the central axis <NUM> of the outlet part is kept small. In the embodiment shown in <FIG>, the distance <NUM> is <NUM>. Due to the small distance <NUM>, the operating handle <NUM> can have a small length <NUM>, and the length <NUM> between the sleeve and operating handle <NUM> can be small. In the embodiment of <FIG>, the length <NUM> of the operating handle <NUM> is <NUM>, and the length <NUM> is <NUM>. The small lengths <NUM> and <NUM> further contribute to the minimalistic appearance of the tap <NUM>.

<FIG> shows that the operating handle <NUM> comprises a cover element <NUM> and a rotating element <NUM>. The rotating element <NUM> may be rotated by the user to open or close the tap <NUM>. The cover element <NUM> is connected to the rotating element <NUM>, thereby covering the front end of the rotating element <NUM>. The cover element <NUM> comprises a screw <NUM>, which forms an integral unity with the rest of the cover element <NUM>. This is clearly visible in <FIG>, where the cover element <NUM> comprising the screw <NUM> is presented as an individual component. The screw <NUM> allows for a qualitative connection between the cover element <NUM> and the rotating element <NUM>. Moreover, the integration of the screw <NUM> within the cover element <NUM> allows for a thin cover element <NUM> and a short length <NUM> of the operating handle <NUM>. In the embodiment of <FIG>, the dimension <NUM> of the cover element <NUM> is <NUM>,<NUM>.

Furthermore, <FIG> shows that the rotating element <NUM> comprises a circumferentially positioned collar <NUM>, which allows to cover an internally positioned slit ring <NUM>. The slit ring <NUM> is typically made of elastic material and is used to avoid a metal-to-metal contact when rotating the rotating element <NUM>. The slit ring <NUM> is also visible in the exploded view of <FIG>. In mounted condition, the slit ring <NUM> is positioned between the rotating element <NUM> and the non-moving inlet housing <NUM>, thereby providing for a fluent and durable rotation of the operating handle <NUM>. In the embodiment of <FIG>, the collar <NUM> is a protrusion along the circular edge of the rotating element <NUM>. The collar <NUM> allows to conceal the slit ring <NUM>, thereby further contributing to the sleek appearance of the tap <NUM>.

In the shown embodiment of the tap <NUM>, the rotating element <NUM> and the cover element <NUM> have a cylindrical outer surface, which is aligned with the cylindrical outer surface of the inlet housing <NUM>. Furthermore, <FIG> and <FIG> show that the outer surface of the rotating element <NUM> is profiled, thereby offering an improved grip. In the shown embodiment, a profile with grooves having a triangular cross section is used. The use of such triangular grooves avoids that dirt such as sand or soil sticks between the profile grooves.

<FIG> further shows that the non-return valve <NUM> comprises a sealing ring <NUM>. Additionally, two O-rings <NUM> and <NUM> are provided for sealing. Moreover, <FIG> and <FIG> show that the inlet housing <NUM> comprises a groove <NUM>. The groove <NUM> lies in a transversal contact surface of the inlet housing <NUM>, the transversal contact surface being substantially perpendicular to the central axis of the inlet housing <NUM>. The groove <NUM> allows to conceal a sealing of the screw thread <NUM>, a sealing which is e.g. provided in tape or cord of teflon or hemp. Therefore, the groove <NUM> contributes to a sleek appearance of the tap <NUM> when the latter is mounted onto a wall, and allows for an easy installation of the tap <NUM>.

<FIG>, <FIG> and <FIG> give a cross section of the tap <NUM>, where the tap <NUM> is mounted resp. in a wall-mounted flange <NUM>, at a cover plate <NUM> and at a building wall <NUM>. The figures illustrate that in various embodiments, the groove <NUM> allows to conceal a sealing of the screw thread <NUM>. Finally, <FIG> shows that the wall-mounted flange <NUM> comprises a notch <NUM> along its circumference. The notch <NUM> allows to mount the flange <NUM> against a building wall being not perfectly flat, while creating the visual perception of a flat surface by means of the straight surface <NUM> being positioned at a certain distance <NUM> of the building wall.

Claim 1:
A tap (<NUM>) for providing an exterior water supply, comprising:
- an outlet part (<NUM>), comprising an intake port (<NUM>) adapted to receive a water flow when said tap (<NUM>) is open, and comprising one or more flow channels (<NUM>) adapted to guide said water flow towards an outlet side of said tap (<NUM>);
- an anti-siphon device (<NUM>) comprised in said outlet part (<NUM>), said anti-siphon device (<NUM>) comprising:
o circumferentially positioned vents (<NUM>);
o a valve (<NUM>) movable between a first and a second position, wherein:
▪ in said first position said intake port (<NUM>) is opened and said vents (<NUM>) are sealed from said one or more flow channels (<NUM>), and
▪ in said second position said intake port (<NUM>) is closed and a passageway is formed between said vents (<NUM>) and said one or more flow channels (<NUM>);
wherein:
- said outlet part (<NUM>) comprises a sleeve (<NUM>) mounted around said anti-siphon device (<NUM>), such that a circumferential slit (<NUM>) is present between said sleeve (<NUM>) and said anti-siphon device (<NUM>), said sleeve (<NUM>) comprising a wall (<NUM>, <NUM>) with varying thickness, and said wall comprising:
o a cylindrical outer surface;
o an upper wall part (<NUM>) with a first thickness, and a lower wall part (<NUM>) with a second thickness smaller than said first thickness, such that in mounted condition said circumferential slit (<NUM>) is formed between said lower wall part (<NUM>) and said anti-siphon device (<NUM>),
- said sleeve (<NUM>) comprises a recess (<NUM>), such that an air passageway is present from the exterior environment to said vents (<NUM>) via said recess (<NUM>) and said circumferential slit (<NUM>),
- said outlet part (<NUM>) comprises a connecter (<NUM>), said connector (<NUM>) comprising a cylindrical part (<NUM>);
CHARACTERIZED IN THAT:
- in mounted condition, the outer surface of said cylindrical part (<NUM>) of said connector (<NUM>) is aligned with said cylindrical outer surface of said wall of said sleeve (<NUM>), thereby together defining a continuous cylindrical surface, and
- in mounted condition, said cylindrical part (<NUM>) of said connector (<NUM>) and said sleeve (<NUM>) are positioned close to each other, leaving an intermediate axial gap (<NUM>) of less than <NUM>.