"THERMOSTATIC MIXER VALVE WITH PRESSURE BALANCER"

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Field of Invention

This invention concerns in general the tap sector and in particular

to the hot and cold mixer valves with a thermostatic regulator for sanitary

plumbing.

State of the Art

In the tapware field taken into consideration, mixer valves in the

form of cartridges, insertable in a tap body, designed to house two

separate hot and cold water inputs and having devices for opening and

closing the water inputs so as to adjust the flow and vary the mixer ratio

of the two types of water depending on the temperature of the mixed

water to be delivered through the output, are well known.

Said mixer valves can be with or without a thermostatic regulator.

When they are without a thermostatic regulator, opening and closing,

delivery adjustment, including the variation in the mixer ratio of the water

is carried out manually using the control lever. On the other hand, in

valves equipped with thermostatic regulators, the variation in the mixer

ratio of hot and cold water is autonomous due to the automatic control of

the temperature of the mixed water delivered.

Furthermore, also known is the application of a hydraulic pressure

balancer on said valves with hot and cold water inputs and suitable to

compensate the pressure variations of the water coming from the water

mains and in this way to prevent fluctuations in flow so as to maintain the

ratio of the delivery of hot and cold water feeding the mixer valve,

constant.

Moreover, according to the sate of the technique, the pressure balancer

is a separate unit that connects up to the mixer valve directly or by the

interposition of hydraulic connections, increasing however the overall

size and complexity of the group.

Only in the case where mixer valves without a thermostatic

regulator has a solution been proposed and achieved, where the

balancer is positioned and housed in a part of the body of the valve itself,

even though in a position transversal to the axis of said body. As far as

is known, the hot and cold water thermostatic mixer valves have never

been provided with an incorporated balancer.

Aims and Summary of the Invention

One of the objectives of this invention is therefore to propose and

achieve a hot and cold water mixer valve with a pressure balancer

positioned advantageously in the valve body, between the latter and the

mixing device, associated with the thermostatic unit, so as not to have

complementary devices either external to the valve itself or added to it.

Another objective of the invention is to propose and realise a

thermostatic hot and cold water mixer valve, which incorporates a

pressure balancer without altering its functionality and without increasing

the dimensions and consequently the usual overal dimensions.

Still another objective of the invention is to supply a hot and cold

water valve mixer, with or without a thermostatic unit, complete with a

coaxial pressure balancer, all in the form of a cartridge having overall

sizes that allow universal use and insertion, without the need for

modifications, in the bodies of taps for bathtubs, showers and the like,

instead of and/or in substitution of the traditional thermostatic mixer

valves without pressure balancers.

A further objective of the invention is supply a hot and cold mixer

valve complete with coaxial balancer and which can be equipped with or

without its own water flow opening and closing devices in output and

possibly associated also with a two-way distributor.

These objectives and implicit advantages deriving from them are

achieved with a hot and cold water thermostatic valve according to at

least claim 1.

Brief Description of Drawings

The invention will however be illustrated and become more evident in the

continuation of this description made in reference to the enclosed

indicative and not limiting drawings, in which:

Fig. 1 shows an enlarged partial section of the mixer valve

complete with pressure balancer;

Fig. 2 shows a cross section view of the valve inserted in a valve

body; and

Figs. 3, 4 and 5 show output systems with two, three or four way

water distribution.

Detailed Description of the Invention

As shown, the mixer valve in question is configured and equipped

as a cartridge to be inserted as a whole in the body of a tap 10. It

comprises a body valve 11 made up of a bottom element 12 and a

second top element 13 , seal fitted and housing the operating

components of the mixer valve.

The body 11 delimits internally a mixing chamber 14 housing a

mixer device 15 and temperature control of the mixed water delivered.

The bottom device 12, delimits a balancing chamber 16 open towards the

mixer chamber and consequently towards the mixer device 15.

The mixer device 15 is associated, in the known way, with a

thermostatic bulb 17 and is subject to axial movements in answer to the

variations in temperature the thermostatic bulb is subjected to in order to

differently open and close the two water input openings 18, 19 to the

mixing chamber.

The movements of the mixer device 15 are opposed by two

different contrasting springs 20, 21 respectively associated with the

device itself and a hood 21 which rests on the summit of the thermostatic

bulb 20.

The temperature of the mixed water can be set as required by

turning a second knob 23, fixed to a turning shaft 24 associated with the

thermostatic bulb 17 by means of a slider 25 which engages with the top

spring 21 and, by means of this, with the hood 22 over the bulb.

The bottom element 12 of the body of the valve 11 has laterally, at

different levels, some separate input passages 26, 27 for the hot and

cold water respectively, and a bottom with an outlet passage of the water

towards the delivery point. The hot and cold water reach the feed

openings 26, 27 receiving the water to be delivered according to arrows

C and F respectively, through passages connected to the body of tap 10.

The balancing chamber 16 houses a pressure balancer 29 in the

form of a piston free to float axially. It has an intermediate portion 30

connected by opposite parts to two annular portions, one lower 31 and

one higher 32, with a smaller internal diameter and each crossed by

holes or radial slots 31', 32', respectively, on a level with the inlet

passages 26, 27. The external surface of the balancer is guided on the

internal surface of the bottom element 12 with the interposition of at least

one gasket, whereas the internal surface of the intermediate portion 30 is

guided on the external surface of the mixer device, with the interposition

of another gasket. The holes or input slots 31 ', 32' are on the opposite

sides of said intermediate portion 30, above and below the fitted gaskets.

The intermediate portion 30 of the pressure balancer 29 subdivides

the balancing chamber 16 into two so-called small chambers with

variable volumes: a first lower small chamber 33 for balancing the hot

water; a second top small chamber 34 for balancing the cold water. The

first small chamber 33 receives from one side, through the radial holes or

slots 31', the hot water from the inlet passage 26 and on the other side it

is in communication with the radial openings 18 feeding hot water into the

mixer valve 14. In the same way, the second small chamber 34 receives

from one side, through the radial holes or slots 32', the cold water from

the inlet passage 28 and on the other side it communicates with the

radial openings 19 feeding cold water into said mixer valve.

As said above, the mixer device 15 sets the feed water inputs 18,

19 to the mixing chamber and is movable axially by the thermostatic bulb

20. This bulb is in contact and is influenced by the temperature of the

water passing through the mixing chamber and, by dilating differently

depending on the temperature of the water, causes the movements of

the mixer device which in this way opens/closes said openings 18, 19

corresponding to the different quantities of the two types of mixed water

to maintain the temperature of the water delivered when mixed, constant.

When the pressure of the hot and cold water on entering the

passages 26, 27 are the same, the floating piston of the balancer 16

remains in a balanced position and the deliveries of the hot and cold inlet

water are even. Consequently, the ratio of hot and cold water to be mixed

does not change and there are no variations in the temperature of the

mixed water delivered.

The position of the floating piston changes only when the pressure

of the hot and/or cold input water changes. In fact, if the pressure of the

hot water that enters the balancing chamber 33 increases, the floating

piston of the balancer moves in the direction to close, more or less

pronouncedly with its first annular portion 31 , the respective inlet

passage of the hot water 26, whereas, from the opposite side, the

second annular portion 32 of the piston opens more or less pronouncedly

the cold water input passage 28. With an increase in the pressure of the

cold water we have the opposite; the ratios of the quantities of the cold

water are changed to maintain the temperature of the mixed water

delivered, constant.

Worthy of note is the fact that the thermostatic mixer valve housing

a coaxial pressure balancer such as the one described beforehand may

also be the type provided with a closing system, and regulation and/or

distribution of the water to be delivered in its base as shown in Fig. 2.

Such a system can be made up of a fixed plate 37 and a mobile plate 38

resting and turning above the fixed one. Said plates 37, 38 are

associated with the bottom passage 28 of the bottom element 12 and can

be held by a covering 39 enclosing the valve body 11.

On one side, the fixed plate can have, for example, two 40, three

41 , or even four 42 output passages, as shown respectively in Figs. 3, 4

and 5 for the delivery of water to an equal number of different user

outlets, using a distributor 43 with the same number of branches.

On the other side the movable plate 38 is attached to the bottom

element 12 of the valve body and has a split or slot 44 which can be

selected and positioned in correspondence with each of the exit

passages 40, 41 , 42 following rotation of the movable plate 38 moved by

said bottom element and carried out using a second knob 45 fixed to the

top part of the valve body 11. Furthermore, the movable plate 38 can be

turned and stopped on the fixed one in a position at a distance from each

output passage so as to close the valve and stop delivery of water. Each

position of the mobile plate can be established by a spring loaded stop

46 which engages with a stop notch 47.