The present invention also relates to a thermostatic device and a thermostatic
5 valve comprising such a device. The invention further relates to a method for
manufacturing such a device.
The invention is particularly concerned with thermostatic devices and valves which are used in the cooling circuits of heat engines, especially those of motor vehicles, heavy-duty vehicles, two-wheelers and stationary engines. However, this
10 field of application is not limiting to the invention, in the sense that the device and the
valve according to the invention can be used in various other fluid circuits, for example gearbox cooling circuits, water circuits, oil circuits, etc.
In many applications in the fluidic field, especially for cooling thermal engines, thermostatic valves are used to regulate the flow of a fluid, i.e. to distribute the fluid in
15 different flow paths, depending on the temperature of the fluid. These valves are said
to be thermostatic, in the sense that the movement of their internal shutter relative to the valve housing is controlled by a thermostatic element, i.e. an element which comprises a body, containing a thermally expandable material, and a piston, immersed in that thermally expandable material. The body and the piston can be
20 moved relative to each other in translation along the longitudinal axis of the piston,
with the piston deploying relative to the body when the thermally expandable material expands. By securely connecting the piston to the valve housing, the extension of the thermostatic element body allows the shutter to be driven relative to the housing, thereby opening and closing a fluid-carrying passage through the housing.
25 In order to seal the contact between the shutter and a fixed seat in the housing,
a seal is known to be integrated in the shutter. This seal, typically made of a flexible material such as rubber or elastomer, is carried by a rigid frame of the shutter, this frame being, in use, connected to the body of the thermostatic element for the purpose of being driven by the thermostatic element. In practice, the seal is held in place on
30 this frame by overmoulding, crimping or form-fitting.
Thus, EP 0 908 809 proposes to overmould a flexible seal onto a rigid frame. For its own part, FR 2 732 088 proposes to crimp a seal in an annular groove of a frame, by locally collapsing the seal over its entire periphery by a wall of the groove, folded inwards. FR 2 819 035 also proposes to fit the seal into a groove in the frame,
35 but by folding a wall of the groove inwards against the seal in a loose fit. These known

2
solutions, based on bending a peripheral part of the frame, require the seal to be
placed in a dedicated groove in the frame, in which the seal is held in place once the
peripheral part of the frame is bent. The cross-sectional area of the frame is therefore
significant, due to the presence of this groove around the body of the thermostatic
5 element. This keeps the outside diameter of the shutter quite large.
In order to overcome this dimensional problem and to offer shutters with a smaller diameter, solutions based on an overmoulding of the frame are currently used. However, this implies that the flexible material, added by overmoulding to form the seal, can only be chosen in certain grades that are compatible with the overmoulding
10 operation. In addition, the overmoulding operation can lead to additional costs due to
cleanliness problems caused by burrs in the flexible material, the presence of adhesive residues, etc.
The purpose of the present invention is to provide an improved thermostatic shutter device, which, while remaining economical to manufacture, induces fewer
15 dimensional and material constraints.
To this end, the invention relates to a thermostatic device for regulating the circulation of a fluid, as defined in claim 1.
The invention further relates to a thermostatic valve as defined in claim 7.
The invention further relates to a method of manufacturing a thermostatic fluid
20 flow control device, the method being as defined in claim 8.
One of the ideas behind the invention is to use the body of the thermostatic element directly to hold the seal in place on the frame, thus avoiding the need for the frame to incorporate a dedicated groove or other similar arrangement, which would increase the transverse dimension of the shutter. According to the invention, the seal
25 is mounted directly around the body of the thermostatic element and is pressed
radially against that body by the effect of the seal being collapsed by the peripheral part of the frame, folded towards the central axis of the thermostatic element. The radial stop formed by the body of the thermostatic element with respect to the seal is effective both during the deformation of the seal resulting from the compression of the
30 latter by the progressively folded peripheral wall, and after the device has been
manufactured in accordance with the invention. The transverse dimension of the device, at the axial level where the seal is located, is limited to the sum of the diameter of the thermostatic element body and the radial thickness of the seal, since no part of the frame is radially interposed between the thermostatic element body and the seal.
35 The device according to the invention can therefore be provided with a small outer

3
diameter. Furthermore, as the invention does not require any overmoulding operation,
the manufacturing cost and material constraints of the seal are limited. Further
advantageous aspects of the device and method according to the invention will be
discussed below.
5 Additional advantageous features of the device and/or method according to the
invention are specified in the other claims.
The invention will be better understood upon reading the following description, given only as an example, and with reference to the drawings, in which:
[Fig. 1] Figure 1 is a perspective view of a thermostatic device according to the
10 invention;
[Fig. 2] Figure 2 is a longitudinal cross-section of the thermostatic device of Figure 1;
[Fig. 3] Figure 3 is an enlarged view of the detail circled as III in Figure 2;
[Fig. 4] Figure 4 is a longitudinal cross-section of a thermostatic valve
15 comprising the device of Figure 1;
[Fig. 5] Figure 5 is a longitudinal cross-section of some components of the device of Figure 1, illustrating the assembly of these components;
[Fig. 6] Figure 6 is a view similar to Figure 5, illustrating an assembly step
subsequent to that shown in Figure 5; and
20 [Fig. 7] Figure 7 is a view similar to Figure 2, illustrating a variant of the
thermostatic device according to the invention.
Figures 1 to 4 show a thermostatic device 1 for controlling the flow of a fluid.
The thermostatic device 1 is shown alone in Figures 1 to 3, while in Figure 4 the
thermostatic device 1 is shown within a thermostatic valve 2. The fluid controlled by
25 the thermostatic device 1 is, for example, a cooling fluid, the valve 2 belonging in
particular to a thermal engine cooling circuit, in particular of a motor vehicle engine, this example not being, however, limiting, as mentioned in the introductory part of the present document.
As shown in Figure 4, the thermostatic valve 2 comprises a housing 3 including
30 parts 4, 5 and 6 in which the thermostatic device 1 is arranged. The parts 4, 5 and 6
of the housing 3 are fixed to each other, e.g. by being integral and/or securely
connected when the thermostatic valve 2 is in operation as shown in Figure 4. In
practice, in Figure 4, the parts 4, 5 and 6 of the housing 3 are only partially and
schematically shown, their form of implementation not being limiting to the invention.
35 In any case, when the thermostatic valve 2 is in its service configuration, the housing

4
3 channels the fluid, defining fluid-carrying paths 2A and 2B: one of these paths
constitutes a fluid inlet while the other path constitutes a fluid outlet. For example,
when the thermostatic valve 2 is part of an engine cooling circuit, channel 2A
constitutes a cooling fluid inlet, coming from the engine that is to be cooled, while
5 channel 1B constitutes an outlet for this cooling fluid, sending it, for example, to a heat
exchanger, such as a radiator, designed to lower the temperature of the fluid passing through it, before this fluid is returned to the engine that is to be cooled.
The thermostatic device 1 comprises a thermostatic element 10 which is centred on a geometric axis X-X. The thermostatic element 10 includes a body 11, centred on
10 the axis X-X and containing a thermo-dynamic material such as a wax. The
thermostatic element 10 further comprises a piston 12 which extends lengthwise along the axis X-X, advantageously being centred on this axis. An axial end portion of the piston 12 is plunged into the thermally expandable material contained in the body 11.
15 For convenience, the remainder of the description is oriented with respect to the
X-X axis, so that the terms “upper”, “top” and the like refer to an element which, in the direction of the X-X axis, faces upwards in Figures 1 to 4, whereas the terms “lower”, “bottom” and the like refer to an element facing in the opposite direction. Thus, in the example considered here, the piston 12 is arranged above the body 11, its end
20 portion, immersed in the body 11, being its lower end portion, while its end portion
emerging from the body 11 is its upper end portion.
In the embodiment considered in the Figures, the body 11 includes a lower barrel 11.1, which is arranged axially opposite the piston 12 and in which the thermally expandable material is stored. In addition, the body 11 includes an upper flange 11.2
25 which is arranged radially protruding from the barrel 11.1 bordering an upper end of
this barrel, i.e. an end of the barrel facing axially towards the piston 12. At the junction between the barrel 11.1 and the flange 11.2, the body 11 forms a shoulder 15 connecting the barrel and the flange to each other. For reasons that will become apparent later, the shoulder 11.3 is chamfered at its junction with the flange 11.2, as
30 is clearly visible in Figure 3.
The body 11 and the piston 12 of the thermostatic element 10 are movable relative to each other along the axis X-X, typically in translation along this axis: under the effect of an expansion of the thermally expandable material, the piston 12 deploys out from the body 11 while, during a contraction of the thermally expandable material,

5
the piston 12 retracts into the body 11 under the effect of a return spring 7 described later.
In the thermostatic valve 2, when in operation, the piston 12 of the thermostatic
element 10 is securely connected to the housing 3. More precisely, in a manner known
5 per se, the upper end part of this piston 12 is securely connected to part 4 of the
housing 3, arranged across the axis X-X. In practice, various forms of implementation are conceivable with regard to the secured connection of the upper end part of the piston 12 to the part 4 of the housing 3: this secured connection can be made either solely by axial support, as in the example illustrated in Figure 4, or by removable
10 securing, of the clipping or sliding fitting type, or by secured connection of the press-
fitting, overmoulding or addition of a mechanical holding system type. In any case, it is understood that when the thermally expandable material contained in the body 11 expands or contracts, the piston 12 is kept immobile with respect to the housing 3, due to the secured connection of its upper end part to the housing part 4.
15 The thermostatic device 1 further comprises a shutter 20 which is movable along
the axis X-X with respect to a fixed seat 5.1 of the part 5 of the housing 3, so as to open and close a fluid-carrying passage defined between that seat and the shutter: within the thermostatic valve 2 in use, when the shutter 20 is pressed against the seat 5.1 as in the operating configuration shown in Figure 4, this shutter closes the
20 aforementioned passage and therefore prevents the flow of fluid between the
channels 2A and 2B, whereas, when the shutter 20 is moved away from the seat 5.1, the shutter 20 opens the aforementioned passage and therefore allows the flow of fluid between the channels 2A and 2B.
In order to control the movement of the shutter 20, the shutter 20 is connected
25 to the body 11 of the thermostatic element in such a way that, within the thermostatic
valve 2 when it is in service, the axial displacement of the body 11 with respect to the housing 3, resulting from the expansion of the thermally expandable material, causes a corresponding movement of the shutter 20 in such a way as to open the aforementioned passage, by axially separating that shutter from the fixed seat 5.1.
30 To control the closing of the aforementioned passage, the shutter 20 is driven
towards the seat 5A by the aforementioned spring 7. In the thermostatic valve 2, this spring 7 is interposed and compressed, along the X-X axis, between the shutter 20 and the part 6 of the housing 3, an upper end turn 7.1 of the spring 7 being pressed axially upwards against the lower face of the shutter 20, while a lower end turn 7.2 is
35 pressed axially downwards against the part 6 of the housing 3.

6
As can be seen from Figures 1 to 3, the shutter 20 comprises a seal 21 and a frame 22. In this example, the seal 21 and the frame 22 together constitute the shutter 20.
The seal 21 is made of elastomer or rubber or, more generally, of a flexible
5 material, in particular in comparison with the frame 22, so that the seal 21 is designed,
when the shutter 20 closes the aforementioned fluid-carrying passage, to be pressed in a flexible, or even elastic, manner against the seat 5.1 of the part 5 of the housing 3 and thus to seal off the contact between that seat and the shutter. Thus, the seal 21 can be described as a seal for the shutter 20, with the understanding that the seal 21
10 extends all around the axis X-X, as clearly visible in Figure 1. The region of the seal
21, thus designed to cooperate by bearing with the seat 5.1 of the housing 3, is referenced 21.1: unlike Figures 1 and 2, in which the region 21.1 of the seal 21 is represented in solid lines, this region 21.1 of the seal 21 is shown in dotted lines in Figure 4 in order to schematically illustrate that, in the operating configuration
15 illustrated by Figure 4, the region 21.1 of the seal 21 interferes mechanically with the
seat 5.1 of the housing 3, being at least partially collapsed and thus inducing a local deformation of the seal 21.
The frame 22 is made of a metallic material or, more generally, of a rigid material, especially compared to the seal 21. The frame 22 is designed to securely
20 support the seal 21, as explained in more detail below, so that in the assembled state
of the thermostatic device 1 within the thermostatic valve 2, the seal 21 is driven together with the frame 22 and the body 11 of the thermostatic element 10 relative to the housing 3 for the purpose of moving the seal relative to the seat 5.1 of the housing 3.
25 The frame 22 is arranged coaxially and around the body 11 of the thermostatic
element 10, ensuring the connection between the shutter 20 and this body 11. In the embodiment considered in the Figures, the frame 22 has a generally annular shape which, in the assembled state of the thermostatic device 1, is centred on the axis X-X and surrounds the body 11 of the thermostatic element 10 over a limited axial height
30 of this body 11. Thus, the shutter 20 is similar to a flap.
As can be seen in Figures 2 to 4, the frame 22 comprises a central part 22.1, facing the axis X-X, and a peripheral part 22.2, facing away from this axis X-X. In the embodiment considered in the figures, the central part 22.1 and the peripheral part 22.2 are connected to each other by an intermediate part 22.3 of the frame 22. These
35 different parts 22.1, 22.2 and 22.3 of the frame 22 extend around the X-X axis.

7
The central part 22.1 of the frame 22 is mounted around the body 11 of the
thermostatic element 10 in such a way as to ensure the connection between the
shutter 20 and this body 11, in particular in such a way that this central part 22.1 and
thus the frame 22 are carried along by the body 11 of the thermostatic element 10
5 when the thermally expandable material of the thermostatic element expands. To this
end, in the example embodiment considered here, the central part 22.1 consists of a ring with an inverted L-shaped cross-section, including a tubular lower wall, encircling the barrel 11.1 of the body 11, and a transverse upper wall, bearing axially against the shoulder 11.3 of the body 11. Of course, other embodiments are conceivable for
10 the central part 22.1, in particular embodiments which, as they do for the
aforementioned ring, provide that the central part 22.1 is mounted around the barrel 11.1 and is arranged in mechanical interference with the shoulder 11.3 along the axis X-X. Furthermore, according to a practical and effective embodiment, the connection between the body 11 of the thermostatic element 10 and the frame 22 is fixed, i.e.
15 without the possibility of relative movement between them: in this case, the central
part 22.1 is advantageously fitted tightly around the body 11, in particular its barrel 11.1.
The peripheral part 22.2 of the frame 22 is shaped so as to pinch the seal 21. More precisely, as clearly visible in Figures 1 and 2, the peripheral part 22.2 is folded
20 towards the axis X-X by partially collapsing the seal 21, the corresponding collapsed
region of the seal 21 being referenced 21.2 in the Figures. In this example, the peripheral part 22.2 consists of an inclined wall with a frustoconical shape, centred on the X-X axis and converging upwards. Regardless of the embodiment, the peripheral part 22.2 pinches the region 21.2 of the seal 21, collapsing this region 21.2 towards
25 the axis X-X by means of local deformation of the flexible material constituting the seal
21. The collapsed region 21.2 is located axially below the region 21.1 of the seal 21,
this region 21.1 not being covered by the peripheral part 22.2 of the frame 22.
The seal 21, thus stressed by collapsing by the peripheral part 22.2 of the frame
22, is held in place on this frame 22 by being pressed, radially to the axis X-X, directly
30 against the body 11 of the thermostatic element 10. The seal 21 is thus embedded,
radially to the X-X axis, between the peripheral part 22.2 and the body 11 of the thermostatic element 10. In the embodiment considered in the Figures, the seal 21 is thus mounted around and supported, radially to the axis X-X, against the flange 11.2 of the body 11. In any case, the radial support of the seal 21 against the body 11 of

8
the thermostatic element seals the contact interface between them, particularly with respect to the aforementioned fluid.
Along the X-X axis, the seal 21 is held axially with respect to the frame 22 by
the peripheral part 22.2 of the frame 22 at the top and by the rest of the frame 22 at
5 the bottom, in particular by the intermediate part 22.3. The intermediate part 22.3 thus
advantageously has, on its upper side, an axial support surface 22.3A for the region
21.2 of the seal 21, as clearly visible in Figure 2.
According to an optional advantageous arrangement, more particularly visible in Figure 3, the seal 21 is, by deformation, partially accommodated axially between
10 the shoulder 11.3 of the body 11 of the thermostatic element 10 and the frame 22, the
corresponding region of the seal 21 being referred to as 21.3. The formation of this region 21.3 of the seal 21 results from the deformation of the seal 21 in the assembled state of the thermostatic device 1 and is advantageously facilitated by the chamfer of the shoulder 11.3 at the junction with the flange 11.2 and/or by a rounding at the
15 junction between the central part 22.1 and the intermediate part 22.3 of the frame 22.
In any case, the region 21.3 of the seal 21 provides an upward axial anchorage for the seal 21 with respect to the body 11 of the thermostatic element.
In a further advantageous optional arrangement, which is more particularly visible in Figure 3, the intermediate part 22.3 has, on its upper side, a recess 22.3B
20 located, radially to the axis X-X, between the central part 22.1 and the axial support
surface 22.3A. This recess 22.3B of the intermediate part 22.3 is provided to accommodate the deformation of the seal 21 in the assembled state of the thermostatic device 1, by receiving a bulging region 21.4 of the seal 21, resulting from the collapsing of the seal 21 in the assembled state of the thermostatic device 1. By
25 providing that the recess 22.3B is constricted downwards, the bulging region 21.4 of
the seal 21 tends to wedge into the recess 22.3B, thereby enhancing the axial restraint of the seal 21 on the frame 22.
In a further advantageous optional arrangement, which may be combined with the above, the intermediate part 22.3 of the frame 22 has a relief 22.3C on its lower
30 side. This relief 22.3C is designed to centre, on the X-X axis, the upper end turn 7.1
of the return spring 7, pressed axially upwards against the lower face of the frame 22.
In the example shown in the figures, the relief 22.3C mates with the spiral 7.1 in a
form-fitting manner and is housed in a substantially fitted manner within the spiral 7.1.
Figures 5 and 6 illustrate an example of a manufacturing method for the
35 thermostatic device 1.

9
In Figure 5, the thermostatic element 10 and the frame 22 are shown already
assembled to each other. This connection between the frame 22 and the body 11 is
achieved by fitting the central part 22.1 of the frame 22 around the body 11 so that
they are connected as described above. Before being connected to the body 11, the
5 frame 22 is produced by folding and/or deep-drawing a sheet metal.
In the assembly step shown in Figure 5, the seal 21 is fitted to the frame 22 around the body 11 of the thermostatic element 10, being brought into direct radial contact with this body 11. In practice, as indicated by the arrows F1 in Figure 5, the seal 21 is threaded axially around the body 11 from the upper end of the body 11 until
10 it reaches the frame 22, where it is wrapped around the flange 11.2. According to a
preferred procedure, the seal 21 is thus slipped around the body 11 so that it is pressed tightly around that body 11: for this purpose, as illustrated in Figure 5, the internal diameter of the seal 21 is provided to be smaller than the external diameter of the flange 11.2 and/or the profile of the seal 21, turned towards the axis X-X, is
15 curved towards this axis. Such a tight fit of the seal 21 around the body 11 improves
the mechanical strength and sealing of the interface between the seal 21 and the body 11 in the assembled state of the thermostatic device 1.
Furthermore, according to a particularly advantageous optional arrangement, which is implemented in the example embodiment considered in the figures, the seal
20 21 has, before its assembly to the rest of the thermostatic device 1, a plane of
symmetry P which, during the assembly of the seal 21 to the rest of the thermostatic device 1, extends perpendicularly to the axis X-X. Thus, as can be seen in Figure 5, the axial side of the seal 21 facing the frame 22 when the seal 21 is fitted to this frame is irrelevant, which facilitates the manufacturing method.
25 Once the seal 21 is in place on the frame 22, a crimping step is carried out, as
shown in Figure 6. The peripheral part 22.2 of the frame 22 is progressively crimped towards the X-X axis, as indicated by the arrows F2 in Figure 6. The seal 21 is then both partially collapsed by the peripheral part 22.2 and pressed, radially to the axis X-X, directly against the body 11 of the thermostatic element 10. Through the
30 deformation of the seal 21, the formation of the seal’s region 21.2, collapsed by the
peripheral part 22.2, induces the formation of the regions 21.3 and 21.4 detailed above.
Figure 7 shows a variant of the thermostatic device 1 whose thermostatic element and frame are identical to those in the previous figures and therefore have
35 the same references, 10 and 22 respectively. The variant of Figure 7 differs from the

10
previous figures by its seal, which is referenced 21’ and which differs from seal 21
essentially by its region 21.1’ intended to mate with the seat 5.1 of the housing 3 of
the thermostatic valve 2. Indeed, rather than having a rounded profile as for the region
21.1 of the seal 21, the region 21.1’ of the seal 21’ is bevelled, forming a frustoconical
5 surface, centred on the X-X axis and converging upwards.
The variant shown in Figure 7 illustrates the multitude of shapes that the seal 21 can take, particularly in its region intended to mate with the seat 5.1 of the housing 3.
In addition, various modifications and variants of the thermostatic device 1 and
10 its production method, as well as of the thermostatic valve 2, described above, are
also possible. For example:
- rather than being securely connected to the body 11 of the thermostatic
element 10, the shutter 20 can be mounted on this body 11 with freedom of movement
along the axis X-X, provided that it is associated with a dedicated return spring; the
15 shutter 20 then incorporates a relief function in the event of overpressure in the
channel 2A; in this respect, the reader may refer to WO 2015/104325;
- the embodiment of the thermostatic element 10 is not limiting, in the sense
that this element can optionally be controlled, i.e. incorporating an electric heating
element, or have various diameters, etc.; and/or
20 - the body 11 of the thermostatic element 10 can, at its lower end, be provided
with a downward extension, which movably carries a shutter other than the shutter 20, in particular in order to control the flow of fluid in another path of the thermostatic valve 2 to regulate a bypass function, for example within an engine cooling circuit.

WE CLAIMS

A thermostatic device (1) for controlling the flow of a fluid, comprising:
- a thermostatic element (10), which defines an axis (X-X) and which comprises a
5 piston (12), extending lengthwise along the axis and intended to be securely
connected to a fluid-carrying housing (3), and a body (11), substantially centred on the axis (X-X) and containing a thermally expandable material, the body being movable along the axis relative to the piston so as to extend the piston relative to the body under the effect of an expansion of the thermally expandable material, and
10 - a shutter (20), which is movable along the axis (X-X) relative to a fixed seat (5.1) of
the housing (3) so as to open and close a fluid-carrying passage and which is
connected to the body (11) of the thermostatic element (10) so that, on expansion of
the thermally expandable material, the body of the thermostatic element drives the
shutter axially relative to the fixed seat,
15 which shutter (20) comprises both a flexible seal (21; 21’), which is adapted to be
pressed sealingly against the fixed seat (5.1) to close the fluid-carrying passage, and
a rigid frame (22), which securely supports the seal,
which frame (22) includes a central portion (22.1), which is mounted around the body (11) of the thermostatic element (10) so as to be driven by the body of the thermostatic
20 element upon expansion of the thermally expandable material, and a peripheral part
(22.2), which is folded back towards the axis (X-X) by partially collapsing the seal (21; 21’)
characterised in that the seal (21; 21’) is held in place on the frame (22) by being pressed radially to the axis (X-X) directly against the body (11) of the thermostatic
25 element (10), under the effect of the collapsing of the seal by the peripheral part (22.2)
of the frame (22).
2. The thermostatic device according to claim 1, wherein the body (11) of the
thermostatic element (10) includes:
- a barrel (11.1), which is arranged axially opposite the piston (12) and in which the
30 thermally expandable material is stored,
- a flange (11.2), which borders one end of the barrel, facing axially towards the piston,
and
- a shoulder (11.3) which connects the flange to said end of the barrel,
wherein the central part (22.1) of the frame (22) is mounted around the barrel (11.1)
35 and is arranged in mechanical interference with the shoulder (11.3) along the axis (X-

12
X), and
wherein the seal (21; 21’) is mounted around and pressed, radially to the axis (X-X), against the flange (11.2).
3. The thermostatic device according to claim 2, wherein the seal (21; 21’)
5 is, by deformation, partially accommodated between the shoulder (11.3) and the
frame (22).
4. The thermostatic device according to any of the preceding claims, wherein
the frame (22) further includes an intermediate part (22.3), which connects the central
part (22.1) and the peripheral part (22.2) of the frame to each other and which, on its
10 side facing axially towards the seal (21; 21’), has an axial bearing surface (22.3A) for
a region (21.2) of the seal collapsed by the peripheral part of the frame.
5. The thermostatic device according to claim 4, wherein the intermediate
part (22.3) of the frame (22) has, on its side facing axially towards the seal (21; 21’),
a recess (22.3B) for receiving a bulging region (21.4) of the seal.
15 6. The thermostatic device according to one of claims 4 or 5, wherein the
intermediate part (22.3) of the frame (22) has, on its side facing axially away from the seal (21; 21’), a centring relief (22.3C) for a return spring (7), which, on contraction of the thermally expandable material, retracts the piston (12) into the body (11) of the thermostatic element (10) and drives the shutter (20) axially with respect to the fixed
20 seat (5.1).
7. The thermostatic valve (2), comprising a housing (3) for carrying a fluid
and a thermostatic device (1), which is in accordance with any of the preceding claims
and of which the piston (12) of the thermostatic element (10) is securely connected to
the housing (3) while the seal (21; 21’) of the shutter (20) is driven together with the
25 body (11) of the thermostatic element and the frame (22) of the shutter relative to the
housing in such a way that the seal is moved relative to a fixed seat (5.1) of the housing to open and close a fluid-carrying passage.
8. A method of manufacturing a thermostatic device (1) for controlling the
flow of a fluid, this method comprising:
30 - a first step of assembly, in which a rigid frame (22) of a shutter (20) and a
thermostatic element (10) which defines an axis (X-X) and which comprises a piston (12), extending lengthwise along the axis, and a body (11), substantially centred on the axis and containing a thermally expandable material, the body being movable along the axis relative to the piston so as to expand the piston relative to the body
35 under expansion of the thermally expandable material, and wherein a central portion

13
(22.1) of the frame (22) is mounted around the body (11) of the thermostatic element
(10) so as to be driven by the body of the thermostatic element upon expansion of the
thermally expandable material,
- a second step of assembly, in which a flexible seal (21; 21’) is fitted to the frame
5 (22), around the body (11) of the thermostatic element (10), being in direct radial
contact with the body of the thermostatic element, and
- a step of crimping, in which a peripheral part (22.2) of the frame (22) is folded over
by crimping towards the axis (X-X) so that the seal (21; 21’) is partially collapsed by
the peripheral part of the frame and thus held in place on the frame by being pressed
10 radially to the axis, directly against the body (11) of the thermostatic element (10),
under the effect of the collapsing of the seal by the peripheral part of the frame.
9. The method according to claim 8, wherein the seal (21; 21’) has a plane of symmetry (P) prior to being attached to the frame (22), which plane of symmetry (P) extends perpendicularly to the axis (X-X) in the second step of assembly.
15 10. The method according to any of claims 8 or 9, wherein in the second step
of assembly, the seal (21; 21’) is pressed tightly around the body (11) of the thermostatic element (10).