GB2523624A - A thermostatic mixer tap - Google Patents

Abstract

A mixer tap comprises a body 1 having hot and cold water inlets 2, 3 and a mixed water temperature control 6 and a mixed water outlet 4. The temperature control 6 controls a mixing cartridge 7. A tap head 5a controls adjustment of the hot water flow. The mixing cartridge 7 has radial channels 9 in which cold water flows and an internal throat, one of the faces of which forms a cold water seat 10. The body 1 contains a channel 13 connected to the tap head 5a and its other end 14 encloses a bottom 15 of the mixing cartridge 7 which has peripheral radial openings 16 via which hot water from channel 13 flows and accesses a throat situated inside the body of the cartridge. One of the faces of the throat forms a hot water seat.

Description

A thermostatic mixer tap The present invention relates to a thermostatic mixer tap, having a cold body and without a non-return valve, for dispensing water, particularly in sanitary installations such as showers, washbasins and sinks.

Thermostatic mixer valves have the advantage of guaranteeing the stability of the delivered water temperature, regardless of hot water and cold water pressure fluctuations and variations in flow; they also provide comfort and protection against burns, more especially. The majority of thermostatic mixer valves for domestic use comprise a tap on the mixed water outlet side, for opening and then closing the flow of water, reguiring non-return valves to be installed at the hot water and cold water inlets to avoid intercommunication of the hot water and cold water when the mixed water tap is closed.

Thus, document US4669653A describes a mixer tap comprising non-return valves at the cold water and hot water inlets.

Similarly, document FR2356068 relates to a mixer tap fitted with non-return valves, but having a structure such that a large volume of water is stagnant, necessarily promoting bacterial proliferation. Moreover, according to this document, the mixed water circulates in contact with the external wall of the mixer tap, which thereby risks being brought to the same temperature as the mixed water.

To guarantee the closure of the non-return valves, it is necessary to place a filter upstream of the cold water and hot water inlets, so as to capture solid particles carried by the water, such as grains of sand, pieces of lime scale, sealing tape, metal particles, etc. In hospital installations, hygienists prefer to avoid the inclusion of filters because these make disinfection of the water systems more difficult.

A further aim of the present invention is to provide a thermostatic mixer valve which can avoid the disadvantages cited above.

Another aim of the present invention is to provide such a thermostatic mixer valve with a simple construction by avoiding the presence of complex shaped cavities in which water can stagnate, thereby promoting bacterial proliferation.

These aims, as well as those which will be described subseguently, are addressed by a thermostatic mixer valve comprising an elongated body having a generally cylindrical shape, comprising, towards one of its ends, a hot water inlet and, towards its other end, a cold water inlet and a mixed-water temperature control component, as well as a mixed-water outlet located more towards the cold water inlet, this temperature control component interacting in a known manner with a mixing cartridge, and which mixer tap is, according to the present invention, characterised by comprising, on the hot water inlet side, a tap head allowing opening and adjustment of the hot water flow, this mixing cartridge including, towards its end opposite the temperature control component, radial channels in which cold water flows and which give access to an internal throat, one of the faces thereof constitutes the cold water seat of the mixer tap, and the body thereof contains a narrow axial channel made from an insulating material, one end of said channel being in connection with the tap head and the other end being flared to incorporate the bottom of the mixing cartridge, the bottom of this mixing cartridge comprising, at its periphery, radial openings via which the hot water from the channel flows and accesses a throat situated inside the bottom of this cartridge, one of the faces of this throat being the hot water seat, a first seal being placed, between the radial channels and the radial openings, on the external wall of the cartridge in contact with the internal wall of the flared end of the channel, in such a way that the hot water is fcrced to flow via the radial openings.

Advantageously, a second seal is placed between the body of the tap and the flared end of the channel incorporating the mixing cartridge.

Preferably, the mixing cartridge includes a shuttle inside which is located a wax capsule and which comprises seals facing the hot water and cold water seats, the hot water and cold water mixing in the core of the shuttle around the wax cell, the mixed water then passing through the radial openings located in the cartridge wal 1 to arrive at the water outlet.

Advantageously, the mixer tap includes a ring which is located between the mixer valve body and the external wall of the cartridge at the mixed water outlet, and which includes peripheral channels to allow passage of the cold water and a radial channel to allow passage of the mixed water, a bushing being screwed into the mixed water outlet and penetrating into the radial channel to immobilise the ring.

Preferably, two seals are arranged between the mixing cartridge and the ring and one seal between the ring and the threaded bushing.

Advantageously, the hot water inlet includes a thermal insulation bushing, connecting with a hollow body which is made from an insulating material and which receives the tap head, this hollow insulating body being held captive inside the mixer valve body by a threaded support nut which interacts with a thread inside this body.

Preferably, there is a bore inside the support nut for accommodating the ceramic head that is fixed by threading into said nut.

The description which tollows and which has no limiting feature, shall be read in association with the appended Figures, where: -Figure 1 is a cross-section of a thermostatic mixer tap according to the present invention; and, -Figure 2 is a larger scale view of part A of Figure 1.

As can be seen from these Figures, a thermostatic mixer tap in accordance with the present invention comprises an elongate body 1, which contains, towards one of its ends, a hot water inlet 2 and, towards its other end, a cold water inlet 3, as well as a mixed water outlet 4 located more towards the cold water inlet 3. The elongate body 1 has a generally cylindrical shape, the hot water inlet 2 and cold water inlet 3 have more or less the same angular posiuion on the elongate body 1 about the axis thereof, and the mixed water outlet 4 has an angular position which is more or less diametrically opposite to that of the inlets 2 and 3, that is to say more or less 1800 relative thereto. However, if necessary, this mixed water outlet 4 can be in an angular position which is orthogonal to that of the hot water inlet 2 and the cold water inlet 3, that is to say more or less 90° relative therto.

The mixer tap comprises, at its end located towards the hot water inlet 2, a lever or control knob 5 interacting with a tap head Sa to open and adjust the hot water flow and, at its other end, located on the cold water inlet side, a mixed water temperature control component or contrcl knob 6.

This temperature control knob 6 interacts in a known manner with a mixer cartridge 7; the cold water admitted by the cold water inlet 3 flows between the mixer cartridge 7 and the internal wall 8 of the mixer tap body 1.

The mixer cartridge 7 comprises, towards its end opposite to the temperature control knob 6, radial channels 9 in which the cold water flows and which gives access to an internal throat, one of the faces of which constitutes the cold water seat 10 of the mixer tap.

The cold water inlet 2 comprises a thermal insulation bushing 11, which is situated in the connection nut. According to the present embodiment, this bushing 11 penetrates perpendicularly into a hollow body 12 made from an insulating material. This hollow body 12 receives the tap head 5a, preferably with ceramic discs, and is held captive in the mixer tap body 1 by a threaded support nut 30, which interacts with a thread in this body 1. There is a bore inside the support nut 30 for accommodating the tap head 5a that is fixed by threading into this support nut 30.

The hollow body 12 is extended by a narrow channel 13 axially arranged in the body 1, facing the tap head 5a.

Thus, the hot water arriving via the bushing 11 penetrates into the hollow body 12, where the tap head 5a is situated.

When this tap head 5a is open, hot water penetrates into the channel 13. The other end 14 of the channel 13 is flared to incorporate the body 15 of the mixing cartridge 7.

The body 15 of the mixing cartridge 7 comprises, at its periphery, radial openings 16 by means of which the hot water from the channel 13 flcws and accesses a thrcat, situated inside the bcdy 15 of this cartridge 7, one of the faces of this throat being the hot water seat 17.

Between the radial channels 9 and the radial openings 16, a first seal 18 is located on the external wall of the cartridge 7 in contact with the internal wall of the flared end 14 of the channel 13, in such a way that the hot water is forced to flow via the radial openings 16.

A second seal 19 is located between the tap body 1 and the flared end 14 of the channel 13, incorporating the mixer cartridge 7; thus, the cold water cannot enter the space situated around the hollow body 12.

In a known manner, the mixer cartridge 7 ccmprises a shuttle inside of which is situated a wax capsule 21 and which comprises seals facing the hot water seat 17 and the cold water seat 10.

Ihe hot water and cold water are mixed in the core of the shuttle around the wax cell 21; then, the mixed water passes through the radial openings 22 located in the wall of the cartridge 7 to arrive at the water outlet 4.

Advantageously, the mixer tap comprises a ring 23 that is located between the mixer body 1 and the external wall of the cartridge 7, facing the mixed water outlet 4; this ring comprises peripheral channels 24 to allow passage of the cold water and a radial channel 25 to allow passage of the mixed water. A bushing 26 is screwed into the mixed water outlet and penetrates into the radial channel 25 tc immobilise the ring 23.

Iwo seals, 27 and 27bis, are located between the mixer cartridge 7 and the ring 23, and another seal 28 is lccated between the ring 23 and the screwed bushing 26, to prevent the cold water mixing with the mixed water.

When a user rotates the knob 5 to close the hot water admission, the wax cell 21 retracts and a spring 29, located in the bottom 15 of the cartridge 7, pushes back the shuttle 20, which has the effect of closing the cold water.

There is a bore inside the support nut 30 for accommodating the tap head 5a that is fixed by threading into this nut.

The arrangement in accordance with the present invention could be reversed, i.e. the temperature adjustment could be controlled on the cold water side, with the reservation that the mixing system is able to fully out off the hot water when the cold water is cut off; this version having the advantage of favouring priority opening of the cold water.

Similarly, it would be possible to locate the ceramic head facing the hot water inlet, in the extension of the bushing 11, in such a way that the hot water is able to exit laterally via the lateral openings of the head, without this falling outside the scope of the present invention.

The main advantage of the present invention is that it does not require non-return valves at the hot water and cold water inlets, and consequently does not require filtering. Further, the standard arrangement for mixer valves is to have the flow adjustment on the right and the temperature adjustment control on the left, with a mixed water flow that crosses the cold water flow complicating the construction of the mixer valve, whereas, in accordance with the present invention, it is the hot water which flows from the hot water inlet located by convention on the left of the mixer valve, towards the temperature adjustment mechanism situated on the right, on the cold water inlet side, which has the advantage of greatly simplifying the construction of the mixer valve and of avoiding complex cavities where stagnant water promotes bacterial proliferation making disinfection programmes more difficult, or pcssibly ineffective.