The present invention relates to a thermostatic valve for a fluid circulation system,
in particular for circulating a cooling fluid for cooling a combustion engine.
Valves provided with a regulating-control sleeve that is movement controlled by
means of a thermostatic element typically equip cooling circuits that are associated with
combustion engines having high engine cylinder capacity, in particular those used in
trucks and certain motor vehicles, for which the flow rates of coolant fluid needed for their
operation are higher than those encountered for combustion engines having lower engine
10 cylinder capacity in which the thermostatic valves used have flap gates.
Indeed, the use of a sleeve generally makes it possible to have a obturator (gate,
plug) that is said to be (pressure) balanced, that is to say, an obturator for which the
difference in the pressures prevailing on both sides of the wall of the sleeve has a
substantially zero value along the direction of movement of the sleeve by the thermostatic
15 element, this direction corresponding in practice to the axial direction of the sleeve.
Conversely, in a thermostatic valve having a flap gate, the latter generally extends in a
plane that is perpendicular to the direction of movement of the flap gate by the
thermostatic element, in such a manner that the difference in pressure prevailing on either
side of the flap gate along this direction attains high values, in particular when the flow of
20 fluid is cut off by the flap gate. The energy needed to dislodge such a flap gate from its
seat is thus then often quite significant, and this is more so when the rate of flow of the
fluid to be controlled is high and is running in the direction of closure of the flap gate.
A thermostatic valve having a sleeve, such as that disclosed in the document USB-
5 018 664, includes a valve body, which delimits a first fluid flow pipe for fluid to flow
25 therethrough, into which a second fluid flow pipe and a third fluid flow pipe lead. This v;:~lve
also includes a flow control sleeve for regulating and controlling the flow of the fluid
through the valve body that is movable within the interior of the valve body so as to place
at least one of the second pipe and the third pipe in communication with the first pipe. The
valve also includes a thermostatic element, containing a heat-expansible
30 (thermodilatable) material whose volume varies according to the temperature of the fluid
flowing through the valve body, this element including a fixed or stationary portion that is
stationary relative to the valve body and a movable portion, which is movable in relation to
the stationary portion as a result of the effect of a variation in the volume of the heatexpansible
material and is connected in translational motion to the sleeve. The fixed or
35 stationary portion of the thermostatic element is attached on to a housing which is
immobilised within the interior of the first pipe. This housing is configured so as to enable
2
the flow there-through of the fluid flowing inside the first pipe. When the engine is cold, the
cooling fluid in its entirety flows through the Bypass loop of the cooling circuit, that is to
say, it passes through in the first and the second pipes. On the other hand, when the
engine is overheating, the cooling fluid coming out of the engine is hot and the sleeve
5 moves as a result of the effect of the expansion of the heat-expansible material. A portion
or all of the cooling fluid is then diverted by the third pipe to a radiator, in order to be
cooled therein.
Moreover, the valve also includes a sealing ring in order to ensure proper sealing
between the sleeve and the valve body. This sealing ring is mounted tightly and press-
1 0 fitted to be in contact with the inner wall of the main pipe so as to ensure an optimal
sealing and to insulate the second pipe and the third pipe from one another. The mounting
of this sealing ring within the interior of the main pipe is thus difficult and requires the
provision of a stop shoulder at the level of the valve body.
In order to overcome this drawback, it is a technique known from the document
15 WO-A-99/24701 to attach the sealing ring to the support housing for supporting the
thermostatic element. In this document, the first fluid flow pipe for the fluid is a through
pipe and a single pipe leads and opens out into this first pipe. When the fluid is very hot,
the sleeve moves out of its seat in the valve body and comes to be bearing against the
support housing for supporting the thermostatic element. The passage of the fluid flowing
20 in the first pipe is closed off, on the one hand, by the sleeve, and on the other hand, by the
sealing ring. In effect, this is designed so as to allow for the fluid to pass through only in a
central manner, that is to say, its peripheral wall is solid or unperforated. However, the
sealing ring is arranged in such a way that it forms an obturator that is not balanced, that
is to say, that the difference in pressures prevailing on either side of its peripheral wall
25 does not have a zero value. There is therefore the fear of the sealing ring possibly getting
deformed, or even breaking when the valve is integrated into a cooling circuit of a heavyduty
engine, with a high rate of flow of the cooling fluid. This type of valve design is
therefore not robust.
It is these drawbacks in particular that the invention is intended to remedy by
30 offering a more robust thermostatic valve and for which there is moreover no problem with
assembling of the sealing ring within the valve body.
To this end the invention relates to a thermostatic valve for a fluid circulation
system, in particular for circulating a cooling fluid for cooling a combustion engine
including a body, which delimits a first fluid flow pipe for fluid to flow therethrough, which
35 extends along a longitudinal axis and into which lead transversely at least a second fluid
flow pipe and at least a third fluid flow pipe; a flow control sleeve for regulating and
3
controlling the flow of the fluid through the valve body, which defines a central axis that is
parallel to the longitudinal axis and which is movable along this axis within the interior of
the valve body so as to place at least one of the second and third pipes in communication
with the first pipe; a thermostatic element. containing a heat-expansible material whose
5 volume varies according to the temperature of the fluid flowing through the valve body,
this element including a fixed or stationary portion that is stationary relative to the valve
body and a movable portion, which is movable longitudinally in relation to the stationary
portion as a result of the effect of a variation in the volume of the heat-expansible material
and is connected in translational motion to the sleeve; a retaining housing for retaining the
10 thermostatic element, which is integrally attached to the stationary portion of the
thermostatic element. which is immobilised within the interior of the first pipe and which
engages by means of sealed contact with the sleeve; and a sealing ring for sealing
between the sleeve and valve body, which is arranged, fixedly with respect to the valve
body, coaxially around the sleeve. In accordance with the invention the housing closes off
15 one end of the first pipe, while the sealing ring is fixedly connected to the retaining
housing for retaining the thermostatic element and comprises at least one flow-through
opening for the fluid to flow through the body volume thereof.
Thanks to the invention, the assembly of the sealing ring within the interior of the
valve body is facilitated since its mounting no longer requires press-fitting. In addition.
20 there is no need to provide for a stop shoulder within the valve body. The sealing ring is
indeed mounted, as one single composite unit, with the retaining housing for retaining the
thermostatic element. In addition, the flow-through openings for the fluid to flow through
that are arranged on its periphery serve the purpose of ensuring that it is not subjected to
the pressure of the fluid flowing to the second pipe and that the only obturator of the valve
25 is the sleeve, which is pressure balanced and adapted to the high fluid flow rates.
According to aspects of the invention that are advantageous but not mandatory. a
thermostatic valve may incorporate one or more of the following characteristic features
taken into consideration according to any technically permissible combination:
- The sealing ring includes a first sealing annular member for sealing between the
30 sleeve and the valve body and a second fastening annular member for fastening to the
housing that is connected to the sealing annular member by means of tabs, the tabs
defining there-between the fluid flow-through openings.
35
- The second sealing annular member includes at least one boss. that is adapted
for being lodged within a peripheral groove of the housing.
- The first sealing annular member of the sealing ring is provided with an 0-ring
seal for sealing with the valve body.
4
- The 0-ring seal is lodged within a peripheral groove of the first sealing annular
member.
- The first sealing annular member of the sealing ring is provided with a lip seal in
order to ensure sealing with the sleeve.
5 -The lip seal is made of Teflon.
- The sealing ring is made of sheet metal.
- The lip seal is crimped within a sheet metal rim of the first sealing annular
member of the sealing ring.
- The sleeve is adapted so as to be tightly pressed in a sealed manner against the
10 housing, in a manner such as to block the passage of fluid between the first pipe and the
third pipe.
The invention will be better understood and other advantages thereof will become
more clearly apparent in the light of the description that follows of an embodiment of a
thermostatic valve in accordance with the principle thereof, given only by way of an
15 example and made in reference to the drawings in which:
20
- Figure 1 is a longitudinal cross section of a thermostatic valve in accordance with
the invention, that is capable of regulating and controlling the circulation of cooling fluid in
a combustion engine and represented in a flow-through or 'by-pass' configuration, for
which the fluid flows normally in the cooling circuit;
- Figure 2 is a cross section that is analogous to the one in Figure 1, in which the
thermostatic valve is represented in another configuration, where the fluid flowing in the
cooling circuit is diverted to a radiator in order to be cooled therein;
- Figure 3 is a perspective view of a sealing ring belonging to the thermostatic
valve represented in the Figures 1 and 2; and
25 - Figure 4 is a view of a larger scale representation of the inset IV illustrated in
Figure 1.
In Figures 1 to 4 is represented a thermostatic 1 that is capable of regulating and
controlling the circulation of cooling fluid. Here, a fluid refers to a liquid, or even a twophase
mixture. The valve 1 is for example used in a cooling circuit for cooling a
30 combustion engine of a vehicle.
The valve 1 includes a valve body 2 for routing of the fluid. This body 2 delimits a
flow-through central pipe 4 for the fluid to flow therethrough. The central pipe 4 extends
along a longitudinal axis X-X.
In the following sections of the description, the terms "high/up", "low/down",
35 "top/upper'' and "bottom/lower'' should be interpreted in the configuration of Figures 1 and
2 and in relation to the longitudinal axis X-X. The central pipe 4 extends downwards to the
5
bottom in Figures 1 and 2 and includes a first chamber 4A and a second chamber 48,
positioned below the chamber 4A. The body 2 delimits two other pipes 6 and 8, which
open out transversely into the central pipe 4, respectively at the level of the chambers 4A
and 48. The pipes 6 and 8 thus do not open out at the same axial level relative to the axis
5 X-X. The pipe 8 is not visible in the cross sectional plane shown in Figures 1 and 2, this is
why it is schematically represented in dotted lines in these figures. In the example shown
in the figures, a single pipe 6 leads and opens into the chamber 4A and a single pipe 8
leads and opens into the chamber 48. However, a plurality of pipes may in practice lead
and open into the same given chamber.
10 Thus the thermostatic valve 1 is a three-way valve. In the example considered, the
fluid in-flow takes place by means of the pipe 4 and the fluid out-flow takes place by
means of the pipes 6 and 8. However, it can be different depending on the mounting of
the valve 1.
In addition, the thermostatic valve 1 comprises a support housing 10 for supporting
15 the thermostatic element 14. This housing 10 closes off one end of the pipe 4, that is to
say, the pipe 4 may be considered to be blind on account of the presence of the housing
10. The housing 10 is immobilised or locked in position in a sealed manner within the pipe
4 and delimits a receiving cavity 10a for receiving the thermostatic element 14. This cavity
1 Oa is turned towards the top. The housing 10 also includes a top crown 12, which
20 surrounds the cavity 1 Oa.
The thermostatic element 14 includes a top cup 140, which has a geometry based
on revolution around the axis X-X and which contains a heat-expansible material, not
shown in the figures, such as a wax. The thermostatic element 14 also includes a lower
rod 142, which extends along the axis X-X and which is immobilised or locked in position
25 in relation to the housing 10. The rod 142 includes a top end that is engaged in a hole of
the cup 140 and a lower end that protrudes out from the cup 140 extending downwards
and which is integrally attached to a head 16. The head 16 cooperates with the housing
10 in a manner so as to ensure the rod 142 is locked in position relative to the latter. The
head 16 is received in the receiving cavity 1 Oa of the housing 10 and comes to be pressed
30 against a bottom wall of the cavity 10a. The cup 140 is movable in translational motion
along the axis X-X relative to the rod 142. More precisely, the cup 140 is movable as a
result of the effect of expansion of the heat -expansible material contained within the
interior thereof. The cup 140 is made out of a thermally conductive material, which is :to
say, that it heats up when in contact with the fluid with which it is steeped. In the
35 configuration shown in Figure 1, the flow of a hot fluid through the pipe 4 results in the
moving of the cup 140 towards the top. Moreover, the cup 140 has an abutment shoulder
I'I,
6
140a for abutting against a liner jacket 18. This shoulder 140a is turned towards the top,
that is to say, that it reduces the transverse cross-section of the cup 140 towards the top.
The liner jacket 18 encircles the cup 140 in the lower part. It is therefore closely
form-fitted to the outer surface of the cup 140. In particular, the liner jacket 18 takes the
5 form of the shoulder 140a of the cup 140 in a manner such that the liner jacket 18 is
driven jointly with the cup 140 in translational motion upon the heating of the heatexpansible
material. The liner jacket 18 has a geometry based on revolution around the
axis X-X and includes a lower edge 180 which is curved in the upward direction and which
advantageously has a hook-shaped form. This hook-shaped form has a recess oriented in
10 the upward direction. The liner jacket 18 comprises a top end 182, which is curved
exteriorly relative to the axis X-X, that is to say which extends away from the cup 140.
The valve 1 also includes a sleeve 20 which, by definition, has an overall tubular
form, centred on an axis X20 that is parallel to, or even combined with the axis X-X. The
sleeve 20 is arranged within the interior of the main pipe 4 above the housing 10. It
15 includes a cylindrical main body 21, that is centred on the axis X-X and whose wall is solid
(unperforated) over its entire periphery. The lower axial end, that is to say the one
oriented towards the housing 10, is adapted so as to come to be pressed in a sealed
manner against the housing 10, in particular in order to block the passage between the
pipes 4 and 8. The housing 10 therefore forms an axial support seat for the sleeve 20.
20 More precisely, the housing 10 includes a sealing ring 106, having a disk shaped form,
which is housed in a peripheral groove 104 of the housing 10. This sealing ring 106 is
designed so as to be forcefully pressed by the sleeve 20 when the cooling fluid is cold, in
a manner such as to block the passage between the pipes 4 and 8. The body 21 of the
sleeve. 20 is, at its top end, provided with an internal peripheral rim from which the arms
25 24 of the sleeve 20 rigidly extend in the direction of the axis X-X. The arms 24 do not
extend radially relative to the axis X-X but rather in a manner that is oblique, and
convergent relative to the axis X-X towards the top. At their free ends, the arms 24 are
connected fixedly to each other by means of an annular crown member 25 belonging to
the sleeve 20. This annular crown member 25 is substantially coaxial relative to the body
30 21. The annular crown member 25 is extended by means of a curled edge that has a hook
shaped form whereof the recess is oriented downwards.
The sleeve 20 is adapted in order to regulate and control the flow of fluid through
the valve body 2 and is movable along the axis X20 within the interior of the body <2 so as
to place at least one of the pipes 6 and 8 in communication with the pipe 4. The curved
35 end 182 of the liner jacket 18 caps the curled edge of the sleeve 20 in a manner such that
the sleeve 20 is blocked in its movement directed upwards by the liner jacket 18.
5
7
A helical spring 30 extends axially between the liner jacket 18 and the sleeve 20.
The spring 30 is centred on the axis X-X and comprises a bottom coil, which is housed in
the recess formed at the lower end 180 of the liner jacket 18 and a top coil, positioned to
be bearing against the annular crown member 25 of the sleeve 20.
The valve 1 also includes a stress absorbing calliper-bracket 40 for absorbing
stresses, which is made of a rigid material, in particular metal. The calliper-bracket 40
includes the openings for passage of the arms 24 of the sleeve 20 and a top end part,
which advantageously has a hook-shaped form, whose recess is oriented downwards.
Moreover, the calliper-bracket 40 includes a bottom end, that is adapted so as to engage
10 mechanically with the crown 12 of the housing 10. In order to do this, this bottom end part
is curved radially in the direction of the axis X-X and comes to bear against the bottom
surface of the crown 12. In this way, the calliper-bracket 40 is attached by hooking into the
housing 10, that is to say it is connected in a fixed manner to the latter.
A return spring 50 of the cup 140 of the thermostatic element 14 is arranged
15 between the calliper -bracket 40 and the sleeve 20. More precisely, the return spring 50 is
a helical spring centred on the axis X-X, which is positioned above the spring 30 and
which comprises a bottom coil positioned to bear against the annular crown member 25 of
the sleeve 20 in the downwards direction and a top coil 42, which is positioned to bear
axially in the upwards direction against the bottom of the recess formed by the top end of
20 the calliper-bracket 40. The calliper-bracket 40 is designed to support the work stresses
generated by the spring 50 during its compression. The calliper-bracket 40 houses the
springs 30 and 50, the thermostatic element 14 and the liner jacket 18.
Finally the valve 1 also includes a sealing ring 60 to ensure proper sealing
between the sleeve 20 and the valve body 2. This sealing ring 60 is more clearly visible in
25 Figure 3. It is coaxially disposed between the sleeve 60 and the wall of the pipe 4. More
precisely, the sealing ring 60 is arranged in the flow-through chamber 4b for the fluid to
flow through. It includes a top annular member 600 and a bottom annular member 602.
The sealing ring 60 is centred on an axis X60, which, in a configuration mounted within
the valve 1, is combined with the longitudinal axis X-X. The annular members 600 and
30 602 are connected to each other by means of three rigid rectilinear tabs 604, which
extend parallelly to the axis X60. The annular members 600 and 602 are therefore
fabricated as a single composite piece with the tabs 604. For example, the sealing ring 60
is fabricated by means of stamping of sheet metal.
The annular member 602 is connected fixedly to the housing 10. More precisely,
35 the annular member 602 includes bosses 602a, which protrude radially to the axis X-X
towards the interior and which engage with a peripheral groove 102 of the housing 10.
I'
"
8
This groove 102 is centred on the axis X-X. In the example, the bosses 602 are three in
number and are distributed in a regular manner around the axis X60. The sealing ring 60
is thus "clipped" on to the housing 10 by insertion of the bosses 602a into the groove 102.
The sealing ring 60 is therefore mounted as one single composite unit with the housing
5 10, which considerably facilitates the mounting in comparison with the assembly of the
valve disclosed in the document US-B-5 018 664. The tabs 604 define there-between
flow-through openings 0604 for the fluid to flow through. More precisely, each opening
0204 is delimited between two successive tabs 604 and between the top annular member
600 and the bottom annular member 602. The openings 0204 have a rectangular contour.
10 The sealing ring 60 is therefore not completely solid over its entire periphery. The fluid can
therefore flow through the sealing ring 60 right across the body volume thereof, that is to
say, along a substantially radial direction relative to the axis X-X, so as to join the pipe 8.
The sealing ring 60 thus does not serve the purpose of obturator, as is the case in the
document WO-A-99/24701. Advantageously, the only obturator of the valve 1 is the
15 sleeve 20, which is pressure balanced and therefore well adapted to be used for high fluid
flow rates.
As can be seen in Figure 4, the top annular member 600 of the sealing ring 60 is
provided with a lip seal 608, which is positioned to bear in a peripheral manner against the
exterior wall of the body 20 of the sleeve 21. The lip seal 608 is made of teflon and
20 ensures proper sealing with respect to the sleeve 20. The lip seal 608 is crimped within a
top rim 600a of the sealing annular member of the sealing ring 600, whose recess is
oriented radially in the direction of the axis X-X, that is to say in a centripetal manner. The
top annular member 600 is also provided with an 0-ring seal 606, which is lodged within a
peripheral groove 600b of the annular member 600. The 0-ring seal 606 is forcefully
25 jammed against the interior wall of a beading 3 of the body 2. It prevents the infiltration of
fluid externally around the sealing ring 60.
Moreover, the bottom annular member 602 covers the exterior edge of the sealing
ring 106. In effect, the bottom annular member 602 comprises a top edge 8602 which is
curved radially to the axis X60 towards the interior and which is positioned to bear against
30 the top annular surface of the sealing ring 106, in such a manner that it maintains the
sealing ring 106 in place within the interior of its housing 104.
In the example of a valve integrated into a cooling circuit for cooling a combustion
engine, the pipe 6 routes a liquid in a cooling loop of the combustion engine that is not
represented while the pipe 8 routes the liquid to a radiator that is not represented, in order
35 for it to be cooled.
9
In Figure 1, the sleeve 20 is found to be in a flow-through or 'by-pass'
configuration, in which the engine is cold. In this configuration, the sleeve 20 closes off the
pipe 8. The cooling fluid entering into the pipe 4 thus flows through in its entirety within the
pipe 6, where it is redirected to the combustion engine. In other words, the liquid remains
5 in the Bypass loop of the cooling circuit of the combustion engine. The liquid indeed does
not need to be cooled since the engine is cold.
When the engine heats up, the cooling fluid flowing through the loop gets heated
up and the cup 140 rises in temperature due to the heat exchange with the liquid. The
heat-expansible material contained in the cup 140 expands, which consequently causes
10 the cup 140 to move axially in the upward direction. The cup 140 in moving drives the liner
jacket 18 by the presence of the shoulder 140a, which compresses the spring 30. The
spring 30 presents a relatively high stiffness, to the extent that the moving of the liner
jacket 18 also drives the movement of the sleeve 20 axially in the upward direction. The
sleeve 20 is therefore connected in translational motion to the movable part 140 of the
15 thermostatic element 14.
The movement of the sleeve 20 in the upward direction is brought about by the
bearing of the top coil of the spring 30 on the annular crown member 25 of the sleeve 20.
The movement of the sleeve 20 takes place against the resilient force of the spring 50. In
other words, the spring 50 gets compressed during the moving of the sleeve 20 in the
20 upward direction. Furthermore, the sleeve 20 rubs against the lip of the seal made of
teflon 608 during its movement in a manner such that there is no liquid flowing around the
sleeve 20.
When the sleeve 20 gets out of its seat, that is to say the housing 10, the liquid
circulating within the interior of the sleeve 20 flows out into the chamber 48 and can
25 escape through the pipe 8. More precisely, the liquid flowing out into chamber 48 escapes
radially through the openings 0604 of the sealing ring 60. The cooling fluid is thus partially
diverted to the radiator in order to be cooled therein.
If the engine is not overheating, the sleeve 20 does not totally close off the pipe 6,
that is to say that only a part of the liquid continues to circulate in the cooling loop of the
30 combustion engine. This intermediate configuration where the pipes 6 and 8 are
simultaneously open is not represented in the figures.
On the other hand, in the event of overheating of the combustion engine, the heatexpansible
material contained within the interior of the cup 140 t:antinues to expand and
the sleeve 20 reaches a high position, in which it comes to bear in a sealed manner
35 against a frustoconical wall 2a that is delimited within the body 2 and which diverges in the
downward direction in relation to the axis X-X. In the high position, the sleeve 20 opens
I'
H
10
completely the 6 pipe, as shown in Figure 2. In this position, the entirety of the liquid
circulating in the pipe 4 traverses the sleeve 20 and escapes through the pipe 8, in the
direction of the radiator.
When the liquid cools down, the heat-expansible material contained in the cup 140
5 does not exert any more expansion forces and the return spring 50 relaxes. The spring 50
thus exerts, on the annular crown member 25 of the sleeve 20, an elastic expansion force
directed downwards, which returns the sleeve 20 elastically in the direction of the housing
10. The moving of the sleeve 20 consequently drives successively a compression and
decompression of the spring 30. The latter thus then exerts on the lower end 180 of the
10 liner jacket 18 a force directed downwards. This force is transmitted to the cup 140 by
means of the shoulder 140a, which makes it possible to return the cup 140 elastically in
the downwards direction, that is to say in the flow-through configuration represented in
Figure 1.
By way of a variant that is not represented, the sealing ring 60 can be attached to
15 the housing 10 by any other appropriate means. For example, the sealing ring 60 may be
welded or bonded on to the housing 10. The sealing ring 60 may also be screwed on to
the housing 10 or attached by a locking means referred to as "bayonet", with which a pin
of the sealing ring 60 penetrates over at least a quarter turn into a curvilinear or angled
channel of the housing 10.
20 According to another variant that is not represented, the sealing ring 60 is
fabricated in plastic. In this case, the lip seal 608 is not maintained in position by means of
crimping of sheet metal but by a ring nut connected on to the sealing ring.
Described here above is the conventional functioning of the thermostatic valve 1 ,
for which the valve 1 is controlled solely by the temperature of the cooling fluid. Quite
25 obviously, by way of a variant that is not represented, the thermostatic element 14 may
be, in addition, driven electrically by connecting, via the housing 10, an electrical
resistance, arranged within the interior of the rod 142, to an electric power source. This
makes it possible in particular to force the cooling liquid to circulate in the radiator in a
period of frost or freezing or even to anticipate an instance of overheating of the engine
30 based on the load weight of the vehicle or the grade steepness.
The technical characteristic features of the variants and embodiments envisaged
here above may be combined with each other in order to generate new embodiments of
the invention.

CLAIMS
1.- A thermostatic valve ( 1) for a fluid circulation system, in particular for circulating
a cooling fluid for cooling a combustion engine, including:
5 a body (2), which delimits a first fluid flow pipe (4) for fluid to flow therethrough,
which extends along a longitudinal axis (X-X) and into which lead transversely
at least a second fluid flow pipe (6) and at least a third fluid flow pipe (8);
10
15
20
25
30
a flow control sleeve (20) for regulating and controlling the flow of the fluid
through the valve body, which defines a central axis (X20) that is parallel to the
longitudinal axis and which is movable along this axis within the interior of the
valve body so as to place at least one of the second and third pipes in
communication with the first pipe;
a thermostatic element (14), containing a heat-expansible material whose
volume varies according to the temperature of the fluid flowing through the
valve body, this element including a fixed or stationary portion (142) that is
stationary relative to the valve body and a movable portion (140), which is
movable longitudinally in relation to the stationary portion as a result of the
effect of a variation in the volume of the heat-expansible material and is
connected in translational motion to the sleeve;
a retaining housing (10) for retaining the thermostatic element, which is
integrally attached to the stationary portion of the thermostatic element, which
is immobilised within the interior of the first pipe and which engages by means
of sealed contact with the sleeve; and
a sealing ring (60) for sealing between the sleeve and valve body, which is
arranged, fixedly with respect to the valve body, coaxially around the sleeve.
characterised in that the housing (10) closes off one end of the first pipe (4), and in that
the sealing ring (60) is fixedly connected to the retaining housing (10) for retaining the
thermostatic element (14) and comprises at least one flow-through opening (0604) for the
fluid to flow through the body volume thereof.
2.- A valve according to claim 1, characterised in that the sealing ring (60) includes
a first sealing annular member (600) for sealing between the sleeve (20) and the valve
' body (2) and a second fastening annular member (6:02) for fastening to the housing (10)
that is connected to the sealing annular member by means of tabs (604), the tabs defining
35 there-between the fluid flow-through openings (0604).
12
3.- A valve according to claim 2, characterised in that the second sealing annular
member (602) includes at least one boss (602a), that is adapted for being lodged within a
peripheral groove (102) of the housing (10). ·
5 4.- Avalve according to any one of claims 2 and 3, characterised in that the first
sealing annular member (600) of the sealing ring (60) is provided with an 0-ring seal
(606) for sealing with the valve body (2).
5.- A valve according to claim 4, characterised in that the 0-ring seal (606) is
10 lodged within a peripheral groove (600b) of the first sealing annular member (600).
15
6;- A valve according to any one of claims 2 to 5, characterised in that the first
annular member (600) of the sealing ring (60) is provided with a lip seal (608) in order to
ensure sealing with the sleeve (20).
7.- A valve according to claim 6, characterised in that the lip seal (608) is made of
Teflon.
8.- A valve according to any one of the preceding claims, characterised in that the
20 sealing ring (60) is made of sheet metal.
25
9 .. - A valve according to claim 6 and claim 8, characterised in that the lip seal
(608) is crimped within a sheet metal rim (600a) of the first sealing annular member (600)
of the sealing ring (60).
10.- A valve according to any one of the preceding claims, characterised in that the
sleeve (20) is adapted .so as to be tightly pressed in a sealed manner against the housing
(10), in a manner such as to block the passage of fluid between the first pipe (4) and the
third pipe (8).