The invention relates to the field of sanitary devices. It relates to a dispenser arranged for dispensing water with an additive, and a corresponding method, as described in the preamble of the corresponding independent claims. US 8'490'891 discloses a showerhead and washing fluid supply device in which a delivery pipe for the washing fluid is arranged inside a water pipe leading from the supply device to the showerhead. The supply device comprises a piston generating a pressure to deliver the washing fluid via its pipe to the showerhead. The piston is activated by the pressure of the mains water. In the showerhead, a manually operated pair of valves allows to switch between a delivery of water or of a foamy mixture of water, washing fluid and air. This mixture is generated in the showerhead and exits the showerhead at another outlet than the water. It is not possible to control the volume of the washing fluid that is dispensed, or its concentration within the mixture. The valve system in the showerhead is mechanically complex and must be operated by hand.

US 2007/235091 shows a water tap for kitchen sinks with two ports for connection to cold and hot water supply lines, and a third port for connection to a special-water supply line, e.g., for supplying filtered or carbonated water. A control valve selects whether mixed-water or special-water is fed to the water discharge head, using two concentric hoses. WO 2007/004050 shows the separate delivery of treated and mains water, comprising a flexible hose for the separate conveyance of treated water and mains water for connection between a spray head provided with at two separate delivery points and a distribution unit for the separate supply of treated water and mains water.

EP 0 313 913 A2 discloses a mixing device in a showerhead, with a base unit with pumps, remotely controlled by buttons on the showerhead. An additive conduit can run in parallel to a water conduit leading to the showerhead, so that the additive is dispensed at the front of the showerhead, through a valve.

WO 2018/122223 A1 and WO 2018/122206 A1 disclose devices and methods for dispensing mixtures of water with additives, via a showerhead, and parameters associated with users of the devices.

US 2013/0291947 A1 disclosed a water tap with an additive conduit leading, in parallel to a water conduit, to a mixer at the outlet of the tap.

It is therefore a possible object of the invention to create a dispenser arranged for dispensing water with an additive of the type mentioned initially, which overcomes the disadvantages mentioned above.

Another possible object of the invention to create a dispenser that allows to precisely control at least one of the time of delivery, volume or concentration of the additive being delivered.

These objects are achieved by a dispenser according to the claims.

The dispenser, which in particular can be a shower, is arranged for dispensing water with an additive. It comprises • a showerhead;

• a shower hose for supplying water to the showerhead;

• at least one additive supply;

• at least one additive conduit for supplying additive from the at least one additive supply to the showerhead;

• wherein the shower hose and the at least one additive conduit are flexible, and are optionally combined with one another;

wherein

• the dispenser comprises at least one additive pump for delivering the additive from the at least on additive supply to the at least one additive conduit,

• an additive pump is arranged and controlled to control delivery of the additive to the showerhead. ln other words, the delivery of the additive to the showerhead and thereby to the flow of water in the showerhead is not controlled by a valve or the like in the showerhead itself, at the end of the additive conduit, but at the beginning of the additive conduit. This allows to control the mixing of the additive with the water in the showerhead itself, in a precise manner, but without increasing complexity of the construction of the showerhead.

In embodiments, the additive pump, when connected to a mains water supply, is arranged to increase the pressure of the additive in the additive conduit to be higher than the pressure of the water in the water supply conduit. The additive is typically a liquid. Instead of water, another liquid can be used.

In embodiments, an additive outlet, arranged at an end of the additive conduit, is arranged in the showerhead. This allows to arrange a mixing arrangement for mixing the additive with the water, in the showerhead, downstream of the additive outlet. The mixing arrangement or mixing unit can be a static mixer comprising elements that generate turbulence in the combined flow of water and additive. This can be done by shaping a conduit for the combined flow, and/or by incorporating elements for generating turbulences in the flow in the conduit.

In embodiments, the showerhead, downstream of the additive outlet, comprises a conduit for the combined flow that maintains at least approximately a laminar flow, up to a region where the combined flow reaches the outlet of the showerhead. In particular, this conduit can have walls that are free from discontinuities, such as edges, ledges or protrusions that project into the conduit.

This can help to minimise energy losses in the combined flow, and thereby increase the effectiveness of the shower in generating the spray.

In embodiments, the additive conduit, at the additive outlet, is open to a volume inside the showerhead for guiding water to an outlet of the showerhead. In other words, there is no valve at the end of the additive conduit. When the pressure in the additive conduit is lower than the water pressure in the showerhead, the additive will be pushed back and remain in the additive conduit.

In embodiments, the additive outlet is arranged to minimise or eliminate the Venturi effect which would draw the additive in to the flow of water.

In embodiments, the additive outlet comprises a check valve. This can prevent the flow of water back into the additive conduit. In embodiments, the check valve is designed to open only if a pressure difference across the check valve exceeds a threshold.

This prevents a flow of additive into the stream of water when the additive pump is not in operation. The threshold for opening the check valve can be, for example, 0.1 bar or 0.5 bar or one bar.

In embodiments, the check valve is a diaphragm valve, for example, a duck-bill valve or a Woods valve.

In embodiments, the additive pump is a positive displacement pump, in particular a peristaltic pump or a diaphragm pump.

This allows to control the amount, and in particular the volume, of the additive being delivered, by controlling the movement of the additive pump. It is not necessary to measure the flow of the additive. The additive can be dosed precisely.

In embodiments, the at least one additive conduit and the shower hose run in parallel to one another.

In embodiments, the at least one additive conduit and the shower hose are attached to one another.

In embodiments, the at least one additive conduit and the shower hose have a length of at least 80 cm or at least one meter.

In embodiments, the at least one additive conduit is arranged inside the shower hose, and in particular

• an inner diameter of the shower hose is between eight and twelve millimetres, in particular at least approximately ten millimetres. • exactly one additive conduit is present in the shower hose, and an outer diameter of the additive conduit is three to six millimetres, in particular at least approximately four millimetres. In embodiments, an inner cross section of the shower hose comprising the one or more additive conduits that remains for guiding the water has an area of less than sixty or less than fifty or less than forty or less than thirty square millimetres.

In embodiments, the water pump is designed to deliver a water flow through the showerhead at a rate of less than five, or less than four, or less than three, or less than two litres per minute.

Such low flow rates are advantageous in combination with the fact that the inner area of the shower hose is reduced by the presence of the additive conduit: By arranging one or more additive conduits within the shower hose, the remaining cross section through which the shower hose can deliver the water to the showerhead is decreased. However, in combination with a low-flow dispenser, this turns out to be an advantage: A low flow dispenser, for example, a shower, requires a small inner diameter of the shower hose, in order to reduce the delay caused by the time the water takes to travel along the shower hose. This delay should be small, since when the user adjusts the water temperature, the change should be felt at the showerhead as quickly as possible. In summary, a shower hose with an outer diameter similar to conventional shower hoses can be used, although it has a diminished inner cross section due to the additive conduit. The overall handling of the shower hose for the end user is the same as for conventional shower hoses, which is an advantage.

In embodiments, an inner diameter of the additive conduit is between one and three or four millimetres, in particular at least approximately two millimetres. In embodiments, the dispenser comprises two or more additive conduits, each with an associated additive supply and optionally an associated additive pump.

This allows to dispense and mix with the water, in a controlled manner, a plurality of additives that are specific to an application of the dispenser.

For example, in a dispenser designed for use in hair care, separate additives can be different types of shampoo, conditioner, colouring agents etc. In embodiments, the dispenser can comprise one a selective activation arrangement for activating the dispensing of one or more of the additives. The selective activation arrangement can comprise a plurality of activation switches or buttons, each one associated with one particular additive. The selective activation arrangement can comprise a selecting element for selecting an additive from two or more additives, and an activation switch or button for activating the dispensing of the selected additive.

Each of the one or more additives can be associated with an additive control input. This can be an input device or input element that allows to adjust the amount of additive. The amount can be expressed, for example,

• as a volume or a weight of the additive to be dispensed in a single "shot" of additive;

• as a volume or a weight of the additive to be dispensed per time unit in a continuous delivery of a mixture of additive and water;

· as a concentration of the additive in the water, dispensed in a single "shot" or continuously. The concentration can be expressed in terms of relative weight or relative volume of additive to water.

For example, a concentration of one half to one gram of additive in ten grams of water can be used. Given a required concentration of an additive and a delivery rate or flow rate of the water pump, the additive pump can be controlled to deliver a corresponding amount or volume of additive.

Or, vice versa, if an amount of additive and a desired concentration are given, specifying a“shot” of additive diluted in water, then the water pump can be controlled to deliver a corresponding amount of water, during a“mixture delivery time”

A set of dispensing parameters can comprise parameters specifying, for one or more additives, an amount of the additive and optionally a duration of time during which the additive is dispensed. The duration of time can be specified relative to a reference point in time. In this way, the set of dispensing parameters can specify, for one or more additives, a trajectory of the amount over time, starting, for example, by triggering the activation button.

Such a trajectory can simply specify the dispensing of two or more additives at the same time, each with a specific concentration. Or a trajectory can specify that first a shot of a first additive (or a combination of additives) is dispensed, and after a certain time, a shot of a second additive (or a different combination of additives) is dispensed, etc.

In embodiments, the dispensing can be terminated by a user input, e.g. by the same or another activation button, and/or by turning off the water supply to the dispenser.

In embodiments, the dispenser is configured to store at least one set of dispensing parameters that specify the dispensing of one or more additives, and to determine a set of dispensing parameters to be used in the operation of the dispenser by

· selecting a set from a plurality of sets of dispensing parameters and/or • modifying a set of stored dispensing parameters and/or

• receiving, from another device, a set of stored dispensing parameters based on at least one of

• information that identifies an operator of the dispenser;

· information that identifies a person or object being treated with the dispenser;

• information that specifies the one or more additives or properties of the one or more additives. In this way it is possible to adapt operation of the dispenser to preferences of a user and/or the task at hand. In the context of hair care, in particular professional hair care, the person being treated is the hairdresser’s client, and the stored dispensing parameters are associated with the client. They can reflect the client’s preferences and/or be adapted to characteristics of the client’s hair.

Furthermore, it becomes possible to adapt the operation of the dispenser to physical and chemical characteristics of the one or more additive. Such characteristics can be solubility, viscosity, concentration of an agent comprised by the additive etc. In embodiments, the water pump is designed to generate a pressure of at least three, at least four, at least five, at least six, at least seven or at least eight bar in the shower hose.

Such a relatively high pressure allows to atomise the water and/or the mixture of water and additive, creating a fine spray. Nevertheless this being a fine spray having small droplets, the droplets have a high kinetic energy. This causes them to be effective in cleaning and rinsing. This is in spite of the fact that the flow rate of the fluid is relatively low. In particular, the combination of a low flow rate with spraying or atomisation under relatively high pressure is advantageous for hair care applications, and in combination with the dispensing of additives as described herein: The combination allows for a rapid switching between the dispensing of a mixture of water and one or more additives, and rinsing. The rinsing can be at a low flow rate because of the effectiveness due to the high pressure, as explained above. And the low flow rate is advantageous in view of the diameter of the shower hose being reduced by the additive conduits inside the hose. In embodiments, the showerhead is arranged to dispense water and a mixture of water and additive through the same outlet of the showerhead, in particular through an outlet that generates a spray of droplets.

In embodiments, the showerhead is configured to dispense a liquid, such as water or water-based mixture, by creating colliding jets of the liquid.

Corresponding outlets using colliding jets are disclosed, for example, in US 8458826 or WO 2011/054120 A, which are hereby incorporated by reference. They typically have one or two or three nozzle sets, each nozzle set having two or more nozzles for creating colliding jets of liquid. Upon collision, the liquid is atomised, generating a fine spray of droplets. Spraying at an increased pressure increases the kinetic energy of the droplets.

In embodiments, the water pump is arranged downstream of a water valve.

In embodiments, no water valve is present. Then the water pump can also have the function of the water valve. In embodiments, the water pump and additive pump, and optionally at least one of the water valve, pressure activated switch, microcontroller are arranged together in a single housing in a base unit. A method for operating a dispenser for dispensing water with an additive comprises the following steps for dispensing a portion of additive (in the form of a mixture of additive and water):

• beginning with a mode of operation in which water is delivered to the showerhead and sprayed by the showerhead;

· reducing or stopping the delivery of water to the showerhead

o for example, by partially or completely closing the water valve and/or reducing the rate of delivery of the water pump or stopping the water pump;

• delivering an additive through the additive conduit to the showerhead while the delivery of water is reduced or stopped;

• resuming delivery of water to the showerhead or increasing the rate of delivery to the same rate as before the reducing or stopping or to a different rate. In embodiments, the delivering of the additive is done by delivering a preset amount, in particular a portion of additive. This can be done as a single“shot” of additive.

In embodiments, the delivering of the additive is done by delivering a preset amount of at least one additive per unit of time. This corresponds to a continuous flow of a mixture of water and additive, with a preset concentration of the at least one additive.

In embodiments, the method comprises the steps of

• resuming delivery of water only for a brief time, to be called“mixture delivery time”, and after the “mixture delivery time”, stopping the delivery of water to the showerhead. As already set forth above, these amounts and time durations (or corresponding frequencies), being dispensing parameters, can be adapted according to user, task and/or additive.

In embodiments, the method comprises the step of

• operating the water pump during the“mixture delivery time” to deliver an amount of water corresponding to the size of a portion of additive delivered by the additive pump, resulting in a controlled concentration of the additive in the water during delivery of the mixture.

For example: given one half to one gram of additive (corresponding, for example, to one half to one millilitre) delivered by the additive pump, they are dissolved in sixteen grams of water, which are obtained by operating the water pump delivering two litres per minute during half a second.

According to a further aspect, and corresponding further embodiments, the mixing of the additive and the water takes place before the shower hose. The additive conduit thus supplies the additive to a mixing unit prior to the connection to a shower hose. Other elements described herein, as far as they are compatible, can be applied in combination with this aspect.

Whereas the description of the invention mainly mentions water as the base liquid being dispensed alone or mixed with one or more additives, it is understood that the invention can be practiced with another liquid can be used instead of water.

Further embodiments are evident from the dependent patent claims. Features of the method claims may be combined with features of the device claims and vice versa. The subject matter of the invention will be explained in more detail in the following text with reference to exemplary embodiments which are illustrated in the attached drawings, which schematically show: Figure 1 a dispenser for one additive;

Figure 2 a dispenser for one additive, with an additive conduit inside a shower hose; and

Figure 3 a dispenser for several additives. The reference symbols used in the drawings, and their meanings, are listed in summary form in the list of reference symbols. In principle, identical parts are provided with the same reference symbols in the figures.

Figure 1 schematically shows a dispenser comprising a base unit 4, a shower hose 13 and a showerhead 14. The base unit 4 is supplied with water through a water supply fitting 1, which for example can be a manually operated tap or valve, an optional pressure reduction valve 2 and a water supply conduit 3. In embodiments, no valve is present in or at the water supply fitting 1. Then the water valve 15 must be designed to handle the mains water pressure. The base unit 4 supplies water to the showerhead 14 through the shower hose 13. The base unit 4 comprises a water valve 15 supplied by the water supply conduit 3 and arranged to be controlled by a control signal, e.g. from a microcontroller 18. A pressure activated switch 5 is arranged to supply a signal depending on a water pressure after the water valve 15. Water from the water valve 15 passes through a pump water fitting 6 to a water pump 12. The water pump 12 delivers the water to the shower hose 13 and thereby to the showerhead 14. The base unit 4 comprises an additive supply 21 and an additive pump 9 that delivers the additive to an additive conduit 16 and thereby to the showerhead 14. The additive supply 21 can be arranged inside the base unit 4 or can be attached to the outside of the base unit 4. Existing one-way or refillable containers can be used. The additive conduit 16 ends in an additive outlet 20, where the additive joins a stream of water delivered by the shower hose 13. Optionally, a check valve 11 is arranged at the end of the additive conduit 16.

The microcontroller 18 is arranged to control the water valve 15, water pump 12 and additive pump 9. It receives input signals from the abovementioned pressure activated switch 5, and optionally user input devices, such as an activation push button or switch 17 and/or an additive quantity or concentration controller 19. The microcontroller 18 can be arranged to initiate the delivery of a mixture of water and additive when the activation switch 17 is activated. The microcontroller 18 can be arranged to control a quantity of the additive being delivered, or a concentration of the additive in the water, in accordance with the input signal from the additive quantity or concentration controller 19.

In other embodiments, the water valve 15 is operated directly by the pressure activated switch 5.

The activation push button or switch 17 can be arranged on the base unit 4, or it can be arranged on a remote unit that is separate from the base unit 4. For example, it can be arranged in a foot pedal, or in the showerhead 14. A switching signal from the activation switch 17 can be transmitted to the microcontroller 18 through a wireless or a wire-bound link.

Likewise, the additive concentration controller 19 can be part of base unit 4 or it can be arranged on a remote unit that is separate from the base unit 4. Information from the additive concentration controller 19 can be transmitted to the microcontroller 18 through a wireless or a wire-bound link.

The activation button 17 and/or additive concentration controller 19 can be implemented in a dedicated device, or by software on a generic device, such as a smartphone or other portable communication device. Figure 2 shows the same elements as Figure 1, but with the additive conduit 16 running through the shower hose 13. Figure 3 shows the same elements as Figure 1 , but with a plurality of additive supplies 21, additive pumps 9 and additive conduits 16. Furthermore, the additive concentration controller 19 comprises a corresponding plurality of controller inputs, one for each additive. In further embodiments, starting from the configuration of Figure 2 or 3, the order of the water valve 15 and pressure activated switch 5 is reversed. Thus, the signal from the pressure activated switch 5 depends on the water pressure in the water supply conduit 3, before the water valve 15. The following can hold for the configurations of all of Figures 1 through 3. The details of a single set of additive supply 21, additive pump 9, additive conduit 16, additive concentration controller 19 etc. and their operation apply to each of such sets, if more than one is present. The additive pump 9 is a pump that allows to control the quantity of additive being delivered. For example, it is a positive displacement pump. A positive displacement pump can be of a rotary-type, reciprocating-type or linear-type. In other embodiments, the additive pump 9 is a non-positive displacement pump, for example, a membrane pump, combined with a sensor for measuring the flow generated by the pump.

While the invention has been described in present embodiments, it is distinctly understood that the invention is not limited thereto, but may be otherwise variously embodied and practised within the scope of the claims.