This invention relates to the control of shower apparatus, and to a method of controlling shower apparatus.

In regards to pumped drainage shower apparatus, a number of systems are known. One is a mechanical or electrical switch, typically on the shower water control module, so that when water first flows the pump in the waste water outlet of the shower base or downstream thereof is activated.

Another kind of system initially developed by Digital Pumps Limited in 2004 utilises a flow meter or flow sensor in a water supply pipe upstream of a shower head. The sensor or sensors is/are connected to a microprocessor based electronic controller which matches pump performance and speed to the detected water flow rate.

Yet another kind of system utilises capacitative sensors at or downstream of the waste water outlet unit in the shower base to detect a change in capacitance and therefore the presence of water in order to activate the pump. The first mentioned system cannot match a flow rate from the shower head, and thus the pump may operate at a non-optimal rate thus generating slurping noise if too fast, or risking flooding if too slow.

The second system, although generally very good, may occasionally generate undesirable slurping noise due to the entraining of air if the flow rate at the shower head suddenly decreases whilst the flow rate at the flow sensor remains high. This could happen, for example, when a user manually lowers a flow rate of water at the shower head.

The final mentioned system is prone to incorrect readings due to the accumulation over time of detritus and other particulate matter, such as soap, hair and exfoliated skin. Furthermore, the control of shower apparatus, whether it is the pump and/or the water flow from the shower head, can be problematic for a disabled, infirm or elderly user if the user cannot, or finds it difficult to, grip or move a control dial or lever on a user interface of the apparatus.

The present invention therefore seeks to provide a solution to these problems.

According to a first aspect of the invention, there is provided shower apparatus comprising a shower base, and at least one load sensing element for monitoring at least a water load on the shower base and for outputting a load signal to a controller for automatically controlling the apparatus based at least in part on the outputted load signal.

Preferable and/or optional features of the first aspect of the invention are set forth in claims 2 to 13, inclusive. According to a second aspect of the invention, there is provided a method of automatically controlling shower apparatus, the method comprising automatically controlling the shower apparatus based on at least a water load imparted to a shower base.

Preferable and/or optional features of the first aspect of the invention are set forth in claims 16 to 20, inclusive.

The invention will now be more particularly described, by way of example only, with reference to the accompanying drawings, in which :

Figure 1 shows a diagrammatic side view of one embodiment of shower apparatus, in accordance with the first aspect of the invention; and Figure 2 is a generalised flow chart of a controller process used to control the apparatus.

Referring to the drawings, there is provided shower apparatus 10 which comprises an electric shower water heater 12, a shower head 14 which is preferably mountable on a wall surface 16 of a shower area and which is in liquid communication with an outlet of the shower water heater 12, a shower base 18 provided below an outlet 20 of the shower head 14 to receive shower water discharged from the shower head 14, and a waste water outlet element 22 at a waste water outlet aperture 24 of the shower base 18 to receive run off waste shower water.

The waste water outlet element 22 includes a first waste pipe 26 which terminates at a liquid inlet of a shower water pump device 28 preferably having an electric motor 30, and a second waste pipe 32 which extends from a liquid outlet of the pump device 28 to a drain.

An electronic controller 34 is also provided for controlling the pump device 28 and optionally a water flow rate through the shower water heater 12.

A load sensing element 36 is interposed between the underneath of the shower base 18 and the support surface 38, typically being for example the floor of the shower area. The shower base 18 is thus supported by the load sensing element 36, so as to be spaced, at least slightly, from the support surface 38 and the walls 16 of the shower area.

In this embodiment, the load sensing element 36 comprises a plurality of spaced apart load cells 40. The shower base 18 is typically square or rectangular in plan view, and one said load cell 40 is provided at or adjacent each corner of the shower base 18. Further load cells 40 may be provided partway or midway between the corners and/or spaced inwardly from the perimeter edge towards the centre as necessity dictates.

Each load cell 40 is preferably an electro-mechanical transducer device. Positioning of the load cells 40 enables deformation or movement of the shower base 18 to be determined, typically through each load cell 40 incorporating a Wheatstone bridge arrangement of strain gauges. An amplified signal output of each load cell 40 is passed through wires or wirelessly to the controller 34 to undergo algorithmic processing.

Although the load cells 40 may utilise strain gauges, a hydraulic or hydrostatic load cell, piezo-electric load cell and/or vibrating wire load cell can be considered. One, more or a combination of the following kinds of load cells 40 can be considered for use : load button, inline rod end, parallel beam, diaphragm, canister, shear beam, double ended shear beam, single ended shear beam, single column, multi-column, membrane, torsion ring, bending ring, pancake, digital electromotive force, bending beam, and/or proving ring.

Although discrete load cells 40 are suggested above, strain gauges or similar devices could be embedded within the shower base 18 itself to determine load- induced flex or deformation of all or a portion or portions of such a shower base, and these types of devices are intended to be incorporated within the meaning of 'load sensing element' used herein and throughout.

The controller 34 preferably includes a microprocessor or programmable controller with a multiple-value non-volatile memory and program software. The algorithm used to process the inputted load signals from the load sensing element 36 is provided as part of the program software, and evaluates the inputted signals based on one, more, all or combinations of : weight of the system at initial configuration and set up to achieve a zero or base point reading, a person stepping onto and/or off the shower base 18, load fluctuations due to user movement on the shower base 18 such as when picking up soap or shampoo, holding supporting rails and/or sitting onto a shower seat, a carer stepping onto and/or off the shower base 18, soap and/or containers for liquids such as shampoo, body wash and conditioner being put on and/or being removed from the shower base 18, and/or shower water discharged from the shower head 14 and/or the discharge being halted. It will be understood that the weight of a user, carer and any soap, liquid container, or showering article such as brush or cloth will result in a noticeable and sudden step change in the load imparted to the shower base 18. However, apart from the point of initiation of water flow from the shower head 14, the flow of water onto the shower base 18 even if the flow rate were to be reduced or increased will not generally result in a step change in the loading on the shower base 18. Rather, the change in loading will be generally smooth and substantially linear, and the algorithm is such as to be able to determine this difference. It may be preferred to commission the shower apparatus 10 by initial operation without a user and any showering accessories being present on the shower base 18. This would provide the controller 34 with a base loading profile directed to loading via only the flowing shower water. This base profile thus excludes order of magnitude step change loading fluctuations can be utilised as a reference during the algorithmic processing to determine whether a change in loading is due to a user and/or accessory or due to change in water flow rate.

Once the algorithmic processing establishes that water flow is present, the controller 34 activates the pump device 28. It may be beneficial, although not necessarily essential, to incorporate a time delay into the controller 34 and/or pump device 28 so that water flow onto the shower base 18 has a chance to accumulate at the waste water outlet aperture 24. This reduces the chance of air being entrained and thus undesirable slurping or gurgling noises.

If the water flow rate is increased or reduced by a user, an output from the load sensing element 36 is analysed, preferably with reference to the base loading profile. If the change in loading is substantially smooth, then it is determined that water flow still exists and the pump device 28 is controlled to maintain its operation but at a revised pumping rate which is optimum or substantially optimum for the newly determined flow rate. If the load sensing element 36 outputs a signal relating to a step change in the load imparted to the shower base 18, the algorithm will determine this, preferably with reference to the base loading profile, and thus take no action.

As can be seen from the flow chart of Figure 2, a generalised pump control process 42 used by the controller 34 first initiates the weight measurement process 44 and for example may take a base reading before any load is imparted to the shower base 18. A loading measurement 46 is then taken by the controller 34 utilising signals from the load sensing element 36 below or within the shower base 18. The load signals received from the load sensing element 36 are analysed by the controller 34 at 48, again preferably based on a base loading profile as mentioned above, to determine whether shower water flow is present. If it is determined that no water flow is present, the controller 34 utilises feedback at 50 from the pump device 28 to determine whether the pump device 28 is activated. If the pump device 28 is in an operational state, a slow- or shut- down process 52 is initiated to reduce the pumping rate or to turn the pump device 28 off and the routine can end. If the pump device 28 is not operational, then the process returns to the measurement step 46 ready for the next use of the shower apparatus 10.

The controller 34 monitors for a change in loading at 54, such as a user standing on the shower base 18 or the water flow rate being adjusted. If there is no change in loading, then the controller 34 determines whether the pump device 28 is activated at 56. If the pump device 28 is not in an operational state, then it is started.

If it is determined that a change in loading has occurred at 54, the change is analysed to determine whether it is a step change and/or whether the change is greater than a loading achievable by shower water at its maximum flow rate from the shower head 14. If no, then the change is determined as being a change in shower water flow rate. This is analysed and the controller 34 adjusts the pumping rate of the pump device 28 accordingly also at 56.

If yes, then the controller 34 ignores the change at 58, since it is determined that the additional load is due to movement of a user and/or carer, and/or due to showering accessories, and thus the activation of the pump device 28 at its present pumping rate should be maintained.

This process 42 is then repeated at a suitable frequency to provide a weight and weight rate-of-change measuring system of equipment. It will be clear to those skilled in the art that the simplified process 42 so described may be further simplified, embellished or adapted to form part or otherwise of other control systems without departing from the fundamental rate-of-change of weight discrimination method so described.

The above-mentioned delay period in starting of the pump device from first monitoring of shower water flow via the load sensing device may be adjustably settable by the installer and/or user or carer, as necessity dictates. This can further optimise the pumping of the waste shower water and reduce pumping and associated noises.

It is also feasible to incorporate one or more flow sensors either upstream of the shower head or downstream of the waste water outlet aperture in the shower base. It may also be feasible to incorporate one or more flow sensors actually in an upper surface of the shower base.

Furthermore, at least one body sensor on or adjacent to the shower base for sensing a user could be incorporated.

The above mentioned flow sensor and body sensor would preferably be outputting to the controller to supplement the data utilised by the algorithmic process.

Although the controller automatically controls the pump device based on an output of the load sensing element, it is feasible that the controller could additionally or alternatively control the on/off function of the water flow from the shower head. In this case, when a user steps onto the shower base, the load sensing element outputs a suitable load bearing signal to the controller which, via the algorithmic process mentioned above, thus activates the flow of shower water. Preferably the shower water would be preheated to the required predetermined temperature prior to discharge. Once the user leaves the shower base, the load sensing element outputs the appropriate signal and the controller halts the flow of water. The process would be relatively straightforward to implement using the above information due to the noticeable step change occurring in the load bearing profile when a user places their mass onto and removes it from the shower base.

The described apparatus includes an electric shower water heater. However, although preferable, this is optional as some showers simply utilise a mixer or direct liquid connections to hot and cold water feeds connected to a boiler, mains supply and/or tank or other means of supply. It is feasible to provide the shower base and load sensing element separately of the shower head and the controller, and this may allow retro-fitting to existing shower installations.

It is thus possible to provide automatic control of shower water supply and shower water drainage apparatus by the use of a load bearing element for monitoring a load imparted to a shower base. The use of a load bearing element is advantageous, since it is separated and substantially isolated from water flow contact, thus dispensing with the need of providing water resistant components and the problems associated with the accumulation of detritus and other particulate matter or debris. The load bearing element enables control of parts of the shower apparatus, such as an electrically powered drain pump, but also enables control of the apparatus through a user's weight rather than requiring dextrous manipulation of controls, which can be difficult if not impossible for some users.

The embodiments described above are provided by way of examples only, and various other modifications will be apparent to persons skilled in the art without departing from the scope of the invention as defined by the appended claims.