Note: Descriptions are shown in the official language in which they were submitted.
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THERMOSTATIC MIXING VALVE WITH SEQUENTIAL
MANUAL CONTROL
TECHNICAL FIELD
This invention relates to a mixing valve for cold and hot water of
the type including a thermostatic device and a manual control device acting
upon
the inlet ports that pass the cold and hot water to a mixing region.
BACKGROUND OF THE INVENTION
According to Italian Patent No. 1,107,182 by the same inventor, a
thermostatic faucet includes a mixer with manual control that sets a mixing
ratio
between cold water and hot water and a thermostatic device that, depending on
the actual temperature of the mixed water, controls a choke valve inserted on
the
hot water supply to the manual control mixer so as to modify the mixing ratio
set
in order to maintain within a certain range the temperature of the mixed water
that is actually delivered.
According to Italian Patent No. 1,279,194, by the same inventor, a
thermostatic faucet includes a mixer with manual control that sets a mixing
ratio
between cold water and hot water and a thermostatic device that, depending on
2 0 the actual temperature of the mixed water, controls a choke valve inserted
on the
cold water supply to the manual-control mixer so as to modify the mixing ratio
set in order to maintain, within a certain range, the temperature of the mixed
water that is actually delivered.
Both of these devices incorporate a certain material separation
2 5 between the manually controlled mixer valve and the thermostatic device
that
complicates its design and installation.
According to Italian Patent No. 1,2273,178, a thermostatic mixing
device to which one can also operate as a faucet includes inlet ports for cold
water and hot water, arranged at the sides of a central outlet pipe. A mixing
3 0 chamber receives water from regulated hot and cold inlet passages and a
thermostatically controlled distribution valve operates so as to control the
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2
opening and closing in opposite directions of the respective regulated inlet
hot
and cold passages so as to maintain, within a certain and adjustable range,
the
temperature of the discharged mixed water. This device can be provided with a
volume flow control valve fox manually and simultaneously changing the useful
opening of both hot and cold inlet pipes. The volume flow valve controls only
the flow volume hut does not have any effect on the mixing action or relative
proportional of flow of hot and cold water. This device presents a general and
particularly advantageous structure, although it does entail the inconvenience
that
temperature regulation is rather poorly sensitive and gives rise to a
temporary
over regulation phenomena (of referred to as an "overshoot"). Temporary
overshoot occurs when upon movement of the temperature adjustment
mechanism to a position corresponding to a given temperature, one initially
gets
an effective temperature change of discharged water that is considerably more
than the desired change. The desired temperature change is reached only after
a
period of time after the thermostatic device had a chance to compensate. The
adjustment of the temperature, controlled by the thermostatic element, is
achieved
by manual control of the position of the thermostatic element and the
distribution
valve operably connected to it, which directly affects the opening of the
respective hot and cold inlets.
SUMMARY OF THE INVENTION
In accordance with one aspect of this invention, a thermostatic
mixing valve can be used alternatively as a thermostatic faucet or as a
thermostatic device for feeding one or several apparatus, each of which is
2 5 provided with its own faucet, or with one or several faucets installed
downstream
from the thermostatic device. The thermostatic mixing valve combines the
advantages of the prior art devices without entailing the installation or
thermostatic overshoot inconveniences. In particular, the invention is a
compact
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3
structure that is easy to make and install and ensures a
high degree of adjustment sensitivity. It further can
provide a guarantee against the delivery of excessively hot
water also in the presence of abnormalities in water supply
and, when it is used as a thermostatic faucet, it
incorporates a manually operated sequential type control
valve mounted in series with the thermostatic valve.
The one aspect of the invention provides a
thermostatic mixing valve including a base having two supply
ports for cold water and for hot water, a mixing chamber,
passages between said supply ports and said mixing chamber,
an outlet port leading from the mixing chamber for the mixed
water, a thermostatic element arranged at least partly in
said mixing chamber, an annular distribution slide valve
controlled by the thermostatic element, said two supply
ports and said outlet being made in a central body
positioned inside said annular distribution slide valve,
said thermostatic mixing valve characterized by: said
distribution slide valve is constructed to restrict and
control the passage between only one of the supply ports and
the mixing chamber, and that a manual control valve is
interposed between said supply ports and said mixing valve
to control flow through said two supply ports.
Preferably, the thermostatic mixing valve
comprises two inlet ports for cold water and hot water, a
mixing chamber, passages between the inlet ports and the
mixing chamber, a discharge port from the mixing chamber for
mixed water, a thermostatic element arranged at least partly
in the mixing chamber, and an annular distribution slide
valve controlled by the thermostatic element. Both inlet
ports and discharge port are in a central body radially
inside the annular distribution slide valve. The annular
distribution slide valve is arranged so as to restrict the
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3a
passage between only one of the inlet ports and the mixing
chamber. A flow and mixing adjustment valve with manual
control of the sequential type is mounted to control the two
inlet ports.
The adjustment of the temperature of discharged
water is set manually by the action of the manually operable
sequential type control valve for the flow and the mixing
action without the manual action directly changing the
position of the thermostatic element and the distribution
slide valve so that one can systematically eliminate the
phenomenon of temporary overshoot. Furthermore, the action
of adjusting the distribution slide valve, controlled by the
thermostatic element, always works in a counteracting
direction from the direction of manual action thereby
limiting its effect. The consequence of two counteracting
activities is that one must make a longer movement of the
manual control to achieve a desired change. The gradation
of adjustment is elongated and the profile of change is
flatter. The quickness and precision of thermostatic
adjustment are then enhanced by the fact that the
distribution slide valve works so as to effectively restrict
or increase flow cross section of only one of the inlet
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4
ports so that the mixing takes place due to the addition or restriction of
only one
flow to the volume of the other flow rather than through inverse variation of
the
volumes of the two flows.
In cases where the valve is used as a faucet, the manual operable
sequential valve also intercepts or shuts off the delivered volume, functions
as a
non-return valve, and adjusts flow rate within certain limits. But the manual
sequential valve inserted in the water supply lines can also be used as a
thermostatic adjustment device for a water supply flow going to one or several
apparatuses, each of which is provided with its own shut off and volume
1 o regulation valve or with one or several faucets inserted in the waterlines
downstream from the thermostatic valves. In these cases, the manual control
valve for the thermostatic valve is adjusted only to determine the desired
temperature and not to intercept a shut-off water flow or regulate it.
In cases where one must ensure an upper limit of the temperature
of the discharge water, the distribution slide valve is so positioned as to
regulate,
by the action of the thermostatic element, the cross-sectional area of the
passage
through which hot water passes from the pertinent inlet port to the mixing
chamber.
On the other hand, in cases where it is not necessary to limit the
2 0 temperature of the discharge water (for example, because hot water supply
is
provided at a limited or non-hazardous temperature), the distribution slide
valve
can also be arranged so as to regulate, by the action of the thermostatic
element,
the cross-sectional area of the passage through which cold water passes from
the
pertinent inlet port to the mixing chamber.
2 5 Preferably, when the valve is intended to be used a thermostatic
faucet the manually operable sequential valve includes a pair of valve plates,
preferably made of hard material with openings therethrough. A first fixed
plate
and a second moveable plate are in sliding contact with each other. The
openings
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in the plates are positioned to ensure in succession a shut-off or intercept
position,
a range of sequential opening positions of the pertinent passage for cold
water
while retaining closure of passage for hot water, a range of positions for the
sequential opening of a passage for hot water while retaining full opening of
the
5 passage for cold water and, finally a range of sequential closing of the
passage for
cold water while retaining full opening of the passage for the hot water. The
two
plates each present an outlet opening that is permanently open to the mixed
flow.
As an alternative, the two ranges of positions can be replaced by a
single range of positions in which there takes place a sequential opening of
the
passages for the hot water and simultaneously a sequential closing of the
passages
for the cold water.
The sequential action can be achieved, for example, with a plate
valve structure that has a first plate that is symmetrical with respect to a
diameter
of the openings therethrough and with a second plate that is asymmetrically
constructed with respect to a diameter of its openings, cooperating with the
first
plate openings. It is immaterial whether the first plate is fixed and the
second
plate is moveable or vice versa. In a particularly convenient arrangement, the
sequential valve includes a fixed base plate intended to be mounted upon a
supply
and delivery housing, and a rotatable plate mounted rotatably on said base
plate
2 0 and which is manually operated. Preferably, the fixed base plate is
mounted in
the supply and delivery housing and the moveable part is mounted in a
rotatable
body of the valve and operable by a handle, lever, or knob.
The valve can be provided with an adjuster to determine and adjust
the maximum temperature at which the delivered water can be adjusted. The
adjuster adjusts the resting position of the thermostatic element and of the
distribution slide valve connected to it. This device can include a cap that
can be
rotated by manual action, mounted through a working threaded connection to the
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6
rotatable body of the valve. As the cap is rotated relative
to the rotatable body, the cap also axially shifts the
support point to the thermostatic element.
In accordance with a broader aspect of the
invention a thermostatic mixing valve has a base having two
supply ports and a rotatable body mounted onto the base and
operably connected to a first valuing surface with a first
and second inlet passages therethrough that are operably
positioned adjacent the two supply ports for controlling
volume flow into the housing. A second valuing member is
annular in shape and movable toward and away from an annular
seat in proximity for restricting and controlling fluid only
from said first inlet passage. The first inlet passage
passes up through the annular seating surface within radial
extent of said annular valuing surface and having a
downstream end in fluid communication with the annular seat
and the annular valuing member to provide a first annular
flow path between the annular seat and the annular valuing
member from radially within the annular valuing member to
radially outside of the annular valuing surface to a mixing
chamber. The first inlet passage is sealed within the
interior of said annular valuing surface with respect to the
second inlet passage from the supply ports to the mixing
chamber. A thermostatic element is axially movably disposed
within the mixing chamber and operably connected to the
annular valuing surface to move the annular valuing surface
axially toward and away from the annular seat for
restricting controlling the flow from only the first inlet
passage into the mixing chamber in response to the
temperature of fluid in the mixing chamber. The mixing
chamber is in fluid communication with an outlet exiting
therefrom.
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6a
The broader aspect of the invention provides a
thermostatic mixing valve characterized by: a base having
two supply ports; a rotatable body mounted onto said base
and operably connected to a first valuing surface with a
first and second inlet passages therethrough that are
operably positioned adjacent said two supply ports for
controlling volume flow into said housing; a second valuing
member being annular in shape and movable toward and away
from an annular seat in proximity for restricting and
controlling fluid only from said first inlet passage; said
first inlet passage passing up through said annular seating
surface within radial extent of said annular valuing surface
and having a downstream end in fluid communication with said
annular seat and said annular valuing member to provide a
first annular flow path between said annular seat and said
annular valuing member from radially within said annular
valuing member to radially outside of said annular valuing
surface to a mixing chamber; said first inlet passage being
sealed within the interior of said annular valuing surface
with respect to said second inlet passage from said supply
ports to said mixing chamber; a thermostatic element axially
movably disposed within the mixing chamber and operably
connected to said annular valuing surface to move said
annular valuing surface axially toward and away from said
annular seat for restricting controlling the flow from only
the first inlet passage into said mixing chamber in response
to the temperature of fluid in said mixing chamber; the
mixing chamber is in fluid communication with an outlet
exiting therefrom.
Preferably, the annular seat opposes an axial end
of said annular valuing member. The second inlet passage
passes up through the first seating surface and through the
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interior of the annular valuing surface within the radial
extent of the annular valuing surface and having a
downstream end in unrestricted fluid communication with the
mixing chamber.
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Alternatively the second inlet passage ends below the annular
valuing member to allow free unrestricted flow about the annular valuing
member
to the mixing chamber and the annular seat is positioned above the annular
valuing member and the first inlet passage passes up through the interior of
the
annular valuing member.
Preferably, a return biasing spring is mounted within the radially
confines of the annular valuing member to axially move said annular valuing
member upon contraction of the thermostatic element.
In one embodiment the return biasing spring is mounted on the top
of a central body within said rotatable body.
BRIEF DESCRIPTION OF THE DRAWINGS
Reference is now made to the accompanying drawings, in which:
Figure 1 is a segmented side elevational view illustrating a first
embodiment of the thermostatic valve according to the invention;
Figure 2 illustrates an embodiment of the fixed plate for the
sequential manual operating valve for controlling the flow and the mixing
action
shown in Figure 1;
Figure 3 illustrates an embodiment of the movable plate for the
2 o sequential manual operating valve;
Figures 4 to 7 illustrate the movable plate of Figure 3 rotated in
various adjusting positions on the fixed plate of Figure 2; and
Figure 8 illustrates a segmented view similar to the one in Figure 1
displaying a second embodiment of the thermostatic valve according to the
2 5 invention.
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DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to Figure 1, a thermostatic mixing valve 10 includes a
rotatable handle body 12 that is rotatably mounted in piping fixture or other
suitable piping fixture 14. The piping fixture 14 includes a cold water supply
16
and hot water supply 18. The rotatable handle body 12 is rotatably mounted to
a
faucet base 17 that is affixed within the fixture 14 by projection 19 inserted
in the
seat 21 of the fixture 14. The body 12 is retained to base 17 by collar 23
threaded
into the seat 21 of fixture 14. Seals 13 are seated on base 17 about a cold
water
inlet port 20 and a hot water inlet port 22.
1 o Rotatable body 12 comprises an inner shell 25 that can be quipped
with a cosmetic operable handle or knob 26, preferably made of thermally
insulating material, so shaped as to facilitate the manual operation for the
rotation
of rotatable body 12. Inside shell 25 there is arranged a central body member
28,
which is fixed to shell 25 for rotation therewith. The central body 28 is
intended
to cooperate with a distribution annular slide valve 44.
The internal body member 28 has a cold water inlet passage 30
aligned with the cold water inlet port 20 and a hot water inlet passage 31
aligned
with the cold water inlet port 22. A central mixed water outlet 33 is in
communication with discharge port 34 and outlet 36 in fixture 14. The passage
30 has an annular shaped downstream end 40 adjacent an annular valve seat 40.
The downstream end is also adjacent the axial upper valve lip 42 of an annular
slide valve 44. Downstream end 46 of hot water inlet 31 is annular in shape
and
is unrestricted by the wide spacing between the lower end 48 of valve 44 and
opposing annular surface 50. There is also a sufficient annular gap between
the
2 5 rotatable body 25 and valve 44 and its mounting collar 57 to provide an
unrestricted passage to flow opening 57 and into mixing chamber 59.
Valve seat 40 is secured to the internal body member 28. The
passage 30 passes axially through the annular valve 44 within its radial
confines.
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The internal body member 28 has an intermediate seal seat 52 that seats a
gasket
54 that seals off the passage 30 from 31 within the axial extend of the
annular
slide valve 44.
The annular slide valve 44 is affixed to the collar 56 via a threaded
engagement 58. The collar 56 and slide valve 44 outlines a mixing chamber 59
between flow ports 57 and mixed water outlet 33. A spring 60 is mounted within
the annular valve 44 and collar 56 and is seated on the top seat 40 on the top
of
the central body 28. The spring 60 biases the valve 44 to engage the seat 40
and
close off passage 38. The collar 56 extends above the internal body section 28
and is operatively affixed through a safety spring release collar 72 and
spring 74
to body section 62 of thermostatic element 64. The thermostatic element 64 has
an expanding piston leg 66 that engages an abutment member 68 that is mounted
in adjustment handle 70. The adjustment handle 70 has a threaded connection 76
to shell 25 and an appropriate seal 75 for mechanically raising and lowering
the
thermostatic assembly 64 within the shell 25. 'Che body section 62 may extend
into the central outlet passage 33 of the internal body 28.
The mixing valve includes a sequential flow rate control valve 80
that includes two ceramic disc plates 82 and 84. Fixed ceramic disc plate 82
is
mounted in base I7. Rotatable (or movable) ceramic disc plate 84 is mounted to
2 0 a bottom of the center body 28. The sequential flow rate control valve 80
is
mounted upstream from the annular slide valve 44. The fixed ceramic disc plate
82 has respective cold and hot supply ports 86 and 88 and a centrally located
mixed water outlet port 90. The movable ceramic disc plate 84 has a cold water
inlet 92 and hot water inlet 94 and a centrally located outlet aperture 96.
2 5 Aperture 96 is in constant alignment with outlet port 90 of fixed ceramic
disc
plate 82 and central outlet passage 33 of body 28 and discharge port 34. The
rotation of the handle 26, and shell 25 with center body 28 rotates the
ceramic
disc plate 84 with respect to disc plate 82 to selectively align or misalign
the
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inlets 92 and 94 with inlets 86 and 88 to control the flow
rate of the hot and cold water.
As clearly illustrated in Figure 2, openings 86
and 88 of fixed plate 82 are symmetrically positioned with
5 respect to a central diameter 97 of the fixed plate. The
openings 86 and 88 have arced, slotted shapes. Other shapes
may also be employed. Inlet openings 92 and 94 of the
movable plate 84, as illustrated in Figure 3, are
asymmetrical with respect to a central diameter 98 of the
10 movable plate 84. Diameter 98 of moveable plate 84, when
the plates 82 and 84 are in the intercept or shut-off
position, as shown in Figure 4, corresponds to the
diameter 96 of the fixed plate. It is also possible to
select other arrangements of the openings 86, 88, 92 and 94
that are equally suitable for bringing about correct
operation (specified below). Furthermore, plates 82 and 84
can switch places such that plate 82, with its openings can
become moveable and plate 84 with its opening can become
fixed.
Plates 82 and 84 together provide for the
sequential adjustment of the flow and the mixing action,
cooperating as shown in Figures 4 to 7 as a function of the
rotation imparted to rotatable body 12 of the thermostatic
valve with respect to fixed base 17.
In Figures 4 to 7, the two plates 82 and 84 are
shown with movable plate 84 superimposed over fixed
plate 82. Openings 92 and 94 of mobile plate 84 thus are in
view, while openings 86 and 88 of fixed plate 82 (marked by
graph-paper-like lines) are entirely or partly covered by
mobile plate 84.
In the position illustrated in Figure 4,
openings 92 and 94 of movable plate 84 are completely
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l0a
misaligned from openings 86 and 88 of fixed plate 82. This
is, therefore, an intercept or shut-off position. On the
other hand, discharge outlets 90 and 96 are permanently
aligned in this position, as in all
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11
other positions of plates 82 and 84, so that outlet passage 33 of central body
28 of
the valve will permanently communicate with outlet discharge 36 of fixture 14.
In the position illustrated in Figure 5, movable plate 84 has been
rotated by a certain angle in a counterclockwise direction (along arrow 100)
with
respect to the position in Figure 4. In the entire range of positions, between
the
positions shown in Figures 4 and 5, the passage opening 92 of movable plate 84
becomes partly or totally aligned to opening 86 of fixed plate 83, while
opening
94 of movable plate 84 retains total misalignment with opening 88 of fixed
plate
82. Therefore, in the rotation from the position in Figure 4 to the position
in
Figure S, there is a progressively growing flow rate that is offered to the
cold
water, while the hot water remains intercepted or shut off.
In the position illustrated in Figure 6, movable plate 24 is further
rotated by a certain angle in the clockwise direction (along arrow 100) with
respect to the position in Figure 5. In the entire range of positions between
the
positions shown in Figures 5 and 6, the passage opening 94 of movable plate 84
becomes partly or totally aligned to opening 88 of fixed plate 82 while
opening
92 of movable plate 84 continues to retain substantially complete alignment
with
opening 86 of fixed plate 82. Therefore, in the passage rotation from the
position
in Figure 5 to the position in Figure 6, there is progressively growing flow
rate
2 0 that is offered to the hot water, while the passage offered to the cold
water
remains fully open. There is thus a progressive addition of hot water to the
cold
water. The axial profile in Figure 1 shows the passages for both the cold
water
and the hot water as being open which corresponds to the profile marked along
line I-I shown in Figure 6.
2 5 Finally, in the position shown in Figure 7, the movable plate has
again been rotated by a certain angle in the counterclockwise direction (along
arrow 100) with respect to the position in Figure 6. In the entire range of
positions between the positions shown in Figures 6 and 7 passage opening 94 of
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12
movable plate 84 continues to retain substantially complete alignment with
opening of fixed plate 82, while opening 92 of movable plate 84 gradually
becomes totally misaligned from opening 86 of fixed plate 82. Therefore, in
the
rotation from the position in Figure 6 to the position in Figure 7, a
progressively
decreasing flow rate is offered to the cold water, whereas the passage opened
to
the hot water remains fully open. There is thus a progressive passage from
mixing action to the delivery of only hot water.
As an alternative, the two ranges of intermediate positions
between the positions of Figures 5 and 7 can be replaced by a single range in
1 o which a gradually growing passage is offered to the hot water, while the
passage
offered to the cold water gradually and simultaneously decreases.
The two plates 82 and 84, with their openings 90 and 96, therefore
provide a sequential control valve 80 for flow and the mixing action, which
can
be controlled manually by rotating body 12 of the valve using handle 26 that
operates a shell 25. With the help of this manual sequential control valve 80,
one
can set a cold water volume to mixing ratio, which are intended to be
subsequently corrected by the action of the thermostatic device 64.
The description refers to the case of a thermostatic mixing valve
that can be used as faucet with a shut off position. In cases where, on the
other
2 o hand, the valve is intended to work as a supplier for one or several
apparatuses
and where the function of intercepting and adjusting the volume is downstream
from this valve 10 the intercept or shut off position and the range of
positions
corresponding to a progressively growing passage offered to the cold water,
while
the hot water remains shut off, can be eliminated.
2 5 The thermostatic device works in the following manner. The
mixing chamber 59 receives hot water through flow ports 27, while cold water
flow's from ring-shaped chamber 38 in respective proportions that are set
manually by the sequential control valve 80 previously described. The hot and
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13
cold water are mixed in mixing chamber 59 and discharged through outlet
passage 33, through discharge port 34 and outlet 36 in fixture 14. This mixed
water surrounds thermostatic element 64, which assumes the same temperature
and expands or contracts correspondingly. The expansion or contraction of
thermostatic element 64 moves the distribution slide valve 44 down or up
respectively. When the water warms the thermostatic element 64, it dilates,
moves slide valve 44 down and the annular seat 42 moves away from the surface
of seat 40 thus widening the passage between annular chamber 38 and mixing
chamber 59. This reduces the resistance against the flow of cold water and the
1 o volume of this flow increases, reducing the temperature of the mixed
water. If at
that point the manual sequential control valve 80 is again adjusted to
increase the
temperature, then there will also be an increase in the dilation of
thermostatic
element 64, and the passage between annular chamber 38 and mixing chamber 29
becomes even wider with even less resistance thus further increasing the flow
rate
of cold water. One can thus see that the thermostatic device 64 tends to act
against manual adjustment so that the latter must be performed with greater
amplitude to attain the desired temperature in the mixed water. The fine
adjustment capability for small temperature changes is thus enhanced.
Furthermore, any voluntary adjustment of the manual sequential
2 o valve to adjust temperature does not directly cause an axial shift in the
distribution slide valve, an axial shift that must successively be compensated
by
the thermostatic device to attain a condition of equilibrium. Thus, there will
be
no phenomena of temporary overshoot.
The operation of handle 70 in this thermostatic valve axially
2 5 moves the entire thermostatic element 64 and collar 56 with slide valve 44
up and
down. However, contrary to what is customary, the movement of handle 70 does
not help adjust the temperature but rather to adjust the maximum limit of the
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14
temperature that can be reached (under normal conditions of supplies) in the
drawn mixed water.
It is obvious that, on the other hand, the temperature of the
delivered water can rise higher than this limit eventually up to the point
where it
reaches the temperature of the hot water supplied only supply pipe 18 if there
are
abnormalities or, at the utmost, if there is a total lack of supply from cold
water
supply pipe 16. Nevertheless, the embodiment described is advantageous both in
cases where the temperature of the hot water supplied by pipe 18 is not
dangerous
and by the fact that the passage of the hot water into the valve is entirely
free
l0 (except for voluntary control) and is therefore particularly favorable in
cases
where the hot water is supplied at low pressure.
If one wishes to introduce a device that prevents the delivery of
hot water with high temperature, one can employ the embodiment according to
Figure 8. The latter to a great extent corresponds to the previously described
embodiment and the corresponding parts, which are labeled with the same
references, will therefore not be described again. The axial cross-section of
this
figure is also the same as that shown in Figure 1.
The basic difference between the embodiment according to Figure
8, as against the embodiment according to Figure 1, is in the fact that
thermostatic
2 o adjustment takes place on the passage 31 of hot water rather than on the
passage
30 of cold water. Inlet passage 30 for cold water has its annular chamber 38
freely empty into mixing chamber 50. On the other hand, inlet passage 31 for
hot
water empties into an annular chamber 46, and the active annular part 48 of
distribution slide valve 44 surrounds this annular chamber 46 and cooperates
with
a lower surface 50 presented by central body 28 to controllably restrict flow
into
mixing chamber 59.
This valve works in a manner identical to the one described
earlier, but thermostatic adjustment following a dilation of thermostatic
element
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23 involves choking or restricting the passage of the hot water rather than
widening the passage of the cold water. It follows from this that in case of
any
anomaly in cold water supply, the volume of mixed water is reduced enough to
stay within the temperature limit set by the valve, and in case of total
absence of
5 cold water supply, the valve would cease to deliver water altogether.
In all of its embodiments, the thermostatic valve according to the
invention can be used as thermostatic faucet that is operated in a progressive
manner, making shell 25 of the valve rotate by virtue of the operation of
handle
26.
10 However, it is also possible to use the valve to supply one or
several apparatus, such as, for example, showerheads, each provided with its
own
volume control and intercept faucet or with one or several faucets inserted in
the
pipe downstream from the thermostatic valve. In this case, the thermostatic
valve
is adjusted manually only to set the desired temperature, while the volume and
15 shut off valves are adjusted downstream on the faucets on the various
apparatuses.
As with all thermostatic valves that do not act as a faucet, which as
such do not ensure a separation between the hot water and cold water supply
pipes, optional non-return valves in the lines may be inserted for ensuring
this
2 o separation.
It must be understood that the invention is not confined to the
embodiments described and illustrated by way of example. Some modifications
have been described and others are within the reach of the expert in the
field; for
example, the shape and arrangement of the passage openings of plates 82 and 84
2 5 can be modified, provided they give rise to the succession of actions
described
earlier. The arrangement of other parts of the valve can also be modified. Cap
70
for adjusting the attainable temperature limit can be omitted when this
adjustment
is predetermined by way of design, or this adjustment can be performed with
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16
setting members that are accessible to the action of a technician but which
the
casual user cannot operate.
These and other modifications and any substitution with technical
equivalents can be introduced in what was described and illustrated above
without deviating from the scope of the invention and the coverage of this
patent.
