The invention relates to a thermostatic cartridge.
The invention applies in particular to the health field and thus interested in mixing valves, both for a sink for a shower for example, which allow "mitigate", that is to say mixing an incoming stream of cold water and an incoming stream of hot water to form a single outgoing stream of water, known as "mixed water" having an intermediate temperature between the respective temperatures of the hot water and cold water.

Such mixers are known thermostatic when possible to regulate the temperature of the mixed water at a substantially constant, adjustable value, regardless of the pressures and the respective temperatures of cold water and hot water, and the flow the mixed water to a certain pressure and flow range. This thermostat function is provided by ad hoc means which are arranged essentially inside a hollow casing, thus forming a preassembled assembly which is described as "thermostatic cartridge" and which is set up in one holding within the tubular outer body of a mixer tap. An example of such a thermostatic cartridge is given in FR 2774740.

Thus, the aforesaid means comprises a thermostatic regulating valve amounts of cold water and hot water, whose movements within the casing are controlled by a first part of a thermostatic element, provided thermosensitive placed the mixed water flow. The second part of the thermostatic element, relative to which the first portion moves in translation substantially along the central axis of the casing when heating the first part, is supported against an adjusting mechanism of the axial position of this second part: by operating this mechanism from outside the casing, the user changes the axial position of the second part of the thermostatic element and, then, the temperature at which the drawer regulates the inlets cold water and hot water, ie the temperature of the mixed water. This mechanism includes a maneuvering screw, which extends from the inside to the outside of the casing via a bore of the casing and which is, inside the casing, screwed into a nut rotatably connected to the casing. Screwing, respectively unscrewing of the screw leads to translate the nut in one direction and respectively in opposite direction and cause correspondingly a movable end piece inside the casing, against which is supported axially the second part the thermostatic element. To allow overtravel of the thermostatic element, that is to say a relative axial spacing of the first and second

parts such that the axial displacement of the control spool by the first part with respect to the casing is prevented due to the axial support formatting said slide against a fixed abutment internal of the casing, an overtravel spring is typically interposed axially between the end piece and the nut: the spring is provided sufficiently rigid so that, as the drawer can be freely moved axially by the first part of the thermostatic element, the spring binds axially the mouthpiece and the nut rigidly.

This adjustment mechanism is satisfactory when the cartridge is in use, especially since it is supplied with cold water and hot water. However, before its connection to the currents entering cold water and hot water, in other words before the hydraulic pressurizing the interior of the casing of the cartridge, the screw of the aforesaid adjusting mechanism has a some freedom of vis-à-vis travel of the envelope, being able to be freely tilted a few degrees relative to the central axis of the casing, by pivoting at the part of the screw arranged in the bore supra of the envelope. This possibility of free travel of the screw originates the radial clearances between the components of the mechanism and the casing of the cartridge, the radial clearance being required for assembly of the cartridge and its correct functioning. In particular, in FR 2,774,740 mentioned above, the screw is guided relative to the casing, so as to align the screw on the shaft, by a single span of the screw, this bearing being arranged to within the aforesaid bore, with the radial interposition of gaskets; thus, within the chamber, the screw is, over the entire extent thereof, radially spaced from the wall of the chamber, and including at a collar of the screw for the axial support of the latter against an internal shoulder of the chamber, a free clearance remaining radially between the collar and the wall of the chamber.

Although the possibility of free movement of the screw has no impact on the performance of the cartridge once it is put into hydraulic pressure, it is negatively perceived by customers who handle the cartridge before commissioning: in Indeed, these customers have the impression that the adjustment mechanism is improperly assembled or damaged. And even after the hydraulic pressure of the cartridge, the screw keeps a certain range of movement, which can be felt as a defect by users.

The object of the present invention is to improve the existing cartridges to limit the displacement of the screw of the adjusting mechanism, while maintaining a simple assembly and a standard design for the cartridge.

To this end, the invention relates to a thermostatic cartridge, as defined in claim 1.

Thus, to improve alignment of the screw on the axis of the chamber, the invention proposes to guide the screw relative to the casing both at the level of the bore through which the screw extends from the inside to the outside of the envelope, but also within the chamber. To do this, the invention provide that the screw includes at least two alignment given on the axis of the chamber, a first range corresponding to the portion of the screw arranged in the aforementioned bore, while the second range is arranged inside the chamber, being separate from the first bearing and the threaded portion of the screw arranged inside the nut. In this way, the screw is guided relative to the casing in two distinct ranges, in particular axially spaced from one another, thus obtaining a long guide together, compared to the short guide realized only at the bore. The magnitude of the tilt screw relative to the casing is greatly reduced or even zero.

In practice, several embodiments can be envisaged to realize the guiding of the second bearing surface of the screw. According to a first embodiment, this guide is not performed directly against the casing, but through the end piece and the nut of the cartridge, as explained in more detail below: This approach allows for the invention without adding any additional component to the cartridge, only the screw and the nozzle being adapted to cooperate directly with each other. According to a second embodiment, this guide is formed directly between the second bearing surface of the screw and a wall of the casing defining the chamber of the latter, with the interposition between the second bearing and the wall of a simple joint compensating a radial clearance therebetween. In both cases, neither assembly nor the total axial dimension of the cartridge according to the invention are not significantly affected, compared to an existing cartridge. Thus, in all cases, the invention runs counter to the prejudice that it would be necessary to reduce all the assembly clearances between the various components of the cartridge to expect to have a significant impact on the amplitude of deflection of the screw relative to the envelope, such a reduction of all games leading to high assembly stresses and / or to oversize the various contact interfaces between components.

Advantageous additional features of the thermostatic cartridge according to the invention are specified in dependent claims.

The invention will be better understood from reading the following description given purely by way of example and with reference to the drawings:

- Figure 1 is a perspective view of a first embodiment of a cartridge according to the invention;

- Figures 2 and 3 are longitudinal sections of the cartridge of Figure 1, in respective planes which are perpendicular to each other;

- Figures 4 and 5 are sections respectively according to the lines IV-IV and VV of Figure 2; and

- Figure 6 is a view similar to Figure 2 illustrating a second embodiment of a cartridge according to the invention.

In Figures 1 to 5 is shown a thermostatic cartridge 1, for example intended to equip a sanitary fitting, such as a sink faucet or shower.

As is clearly visible in Figures 1 to 5, the cartridge 1 comprises, as main external component, a hollow shell 10, for example plastic. This casing 10 has a tubular overall shape, extending in length about an axis XX. The internal volume of the envelope 10 forms a room 1 1 which is centered on the axis XX and which extends along said axis, between the opposite axial ends of the casing 10.

For convenience, the following description is oriented relative to the casing 10, in the sense that the terms "inner" and "outer" are understood with respect to the room 1 1. Similarly, the terms "top" and "upper" means a direction along the axis XX, to one of the longitudinal ends of the casing 10, namely the end facing the upper part of Figures 2 and 3, while the terms "bottom" and "lower" means a direction opposite direction.

Thus, between the high and low ends of the casing 10, the room 1 1 is delimited by the inner face of a tubular wall 12 of the casing 10, centered on the axis XX.

In the exemplary embodiment considered here, the casing 10 includes, at its lower end, a socket 13 which is fastened fixedly, for example by screwing, to the rest of the casing 10, extending it downwards. This sleeve 13 thus constitutes the lower end portion of the tubular wall 12. In addition, in the example shown in the figures, the rest of the casing 10 is one piece, it being understood that, in a variant not shown, this package may be incorporated several portions fixedly secured to each other by any suitable means, in the same way that the sleeve 13 is fixedly secured to the remainder of the casing 10. of course, in a variant not shown, the sleeve 13 may be integrally provided with all or part of the remainder of the envelope 10.

In the assembled configuration of the cartridge 1, as shown in the figures, the casing 10 can be fitted sealingly to the interior of a hollow body of a

tap, not shown in the figures, with the radial interposition of seals between the outside of the casing 10 and the inner face of said body.

The cartridge 1 makes it possible to regulate the temperature of a mixed water M coming out of the cartridge and obtained by mixing an incoming C hot water and a cold water incoming F. To do this, as explained progressively below, the cartridge 1 comprises a drawer 20, a thermostat element 30 and a return spring 40, and an adjusting mechanism for the axial position of the thermostatic element 30, this mechanism including a tip 50, a nut 60, a spring 70 and a screw overtravel 80. All the above components 20, 30, 40, 50, 60, 70 and 80 are at least partially arranged in the room 1 1.

As shown in Figures 2 and 3, the slide 20 is mounted movable, particularly in translation substantially along the axis XX, inside of the chamber 1 1, between two opposite end positions in which the slide closes respectively the entry of hot water C in chamber 1 1 and the inlet of cold water F in room 1 1. In the above two extreme positions, one and respectively the other of the opposite axial ends of the spool 20 are supported against corresponding seats respectively delimited by the casing 10, in particular by internal shoulders of the envelope. To reach the seat associated with the hot water C, it passes radially through the casing 10 which delimits for this purpose one or more peripheral holes 14 through which hot water enters the C 1 and B 1 which are indicated by dotted lines in Figure 2. Similarly, to reach the seat associated with the cold water F, the latter radially through the casing 1 1 which delimits this purpose one or more peripheral slots 15, through which cold water enters F room 1 1 and which are indicated in dashed lines in Figure 2. in the assembled state of the cartridge 1 and when the cartridge is mounted in a faucet, the lights 14 and 15 are respectively supplied with hot and cold water from outside of the casing 1, typically by passages defined by the body of the aforementioned valve.

Depending on the position of the slide 20 relative to the casing 10, between said two extreme positions, the amounts of hot water C and cold water F entering the room 1 1 are controlled and their mixture in the chamber form the mixed water M coming out of the chamber through a hole 16 defined for this purpose by the casing 10 at the lower end thereof, as indicated schematically in Figure 2.

The position of the spool 20 in the room 1 1 is controlled by the thermostatic element 30. For this purpose, the thermostatic element 30 includes a first portion 31, heat, which is arranged in the room 1 1 so that the mixed water M flows over this portion 31, and which is linked to the slide 20 at least in translation

parallel to the axis XX. In practice, the tray 20 may be fixedly secured to the portion 31 of the thermostatic element 30, and by any suitable means, for example by screwing. The thermostatic element 30 also includes a second portion 32 which is movable in translation substantially along the axis XX relative to the first part 31. The first part 31 is provided for, during heating, the spacing of the actuating portion 32 vis-à-vis the portion 31: the portion 31 and acts on the lower end of the portion 32, by moving the latter upward relative to the portion 31. The practical embodiment of the thermostat 30 is not restrictive of the invention, the thermostatic element being also indicated schematically in Figure 2. In a practical embodiment, the part 31 contains a heat-expandable material which, under the action of heat of the mixed water M flowing along the portion 31 expands and causes the relative spacing of the portion 32. an alternative embodiment is to provide the thermostatic element 30 as an actuator of shape memory alloy.

Whatever the embodiment of the thermostatic element 30, the return spring 40 tends to return the parts 31 and 32 towards one another, particularly during cooling of the part 31. To do this, in a manner known per se and as indicated only schematically in Figure 2, the return spring 40 is interposed axially between the shell 10 and the thermostatic element 30.

As is clearly visible in Figures 2 and 3, the upper end of the portion 32 of the thermostatic element 30 is supported axially against the tip 50, this brought into contact resulting from the action of the return spring 40. It will be understood that the end piece 50 controls the axial position of the part 32 of the thermostatic element, ie the height of the portion 32 relative to the casing 10.

The tip 50 is mounted in the room 1 1 movably along the axis XX.

As is clearly visible in Figures 2, 3 and 5, this nozzle is preferably provided with a collar 51, which in the exemplary embodiment, is located at the lower end of the tip 50 and which extends radially projecting from the rest of the endpiece so as to be received, with radial play, in the tubular wall 12 of the casing 10. by limiting the radial clearance cited in obtaining the axial movement of the tip 50 in room 1 1 the collar 51 is advantageously guided relative to the casing 10 by sliding contact therewith, so as to align the tip 50 on the axis XX. The advantage of this guiding of the tip 50 will appear slightly later.

Furthermore, the end piece 50 form, if appropriate at its flange 51, an axial support down to the overtravel spring 70 while the latter is supported axially upwardly against the nut 60. d other words, the spring 70 overtravel

is interposed axially between the endpiece 50 and the nut 60. The overtravel spring 70 has a sufficiently high rigidity so that in the assembled state of the cartridge 1, it binds axially the end piece 50 and the nut 60 l one to the other rigidly as the axial displacement of the spool 20 by the portion 31 of the thermostatic element 30 relative to the casing 10 is free. In other words, as the slide 20 is movable downwardly axially without interfering with the casing 10, in particular without abut axially against the seat associated with the hot water C, the endpiece 50 and the nut 60 form, in the spring action of overtravel 70, a rigid subassembly, in particular as regards the axial position of this sub-assembly relative to the casing 10. however, since the displacement of the slide 20 towards the low is prevented, typically by axial interference with the casing 10, the spring 70 is provided overtravel to deform under the effect of the upward movement, actuated by the portion 31, the portion 32 of the thermostatic element 30 : by deformation of the spring overtravel 70, the tip 50 may then be translated upwardly, without changing the axial position of the nut 60. This prevents deterioration of the cartridge 1 during a significant heating of thermoelement 30, co nduisant the deployment of the portion 32 of overtravel, compared with the maximum stroke of the slide 20 between its two extreme positions vis-à-vis the fixed seating of the casing 10, respectively associated with the hot water C and water cold F.

In an arrangement whose interest will appear later, the endpiece 50 and the nut 60 are radially fitted to each other when the overtravel spring 70 links the tip and the nut axially to other rigidly. To do this, in the embodiment considered in the figures, the tip 50 defines, preferably at its upper end, a frusto-conical surface 52 flaring upwardly and facing the nut 60. At the same time, nut defines, preferably at its lower end, a tapered surface 61, also flared upwardly and arranged to be applied against the frustoconical surface 52 of the nozzle 50, as shown in figures 2 and 3 when the spring overtravel 70 binds axially the end piece 50 and the nut 60 to each other rigidly, these frustoconical surfaces 52 and 61 are applied one against the other under the action of the spring overtravel 70, thus adjusting radially tip and the nut to each other by centering on the respective geometric axes of the frustoconical surfaces 52 and 61, then combined with each other. This radial fit cooperation between the frustoconical surfaces 52 and 61 is reversible, in the sense that these frusto-conical surfaces are disengaged from each other when the spring overtravel 70 is deformed to allow the relative displacement upwardly of the tip 50 relative to the nut 60.

As shown in Figures 2 to 4, the nut 60 is mounted in chamber 1 1 in order to, at the same time, be axially displaceable relative to the casing 10 and be coupled in rotation about the axis XX to this envelope. To do this, in the exemplary embodiment considered here, the face of the nut 60 facing the inner face of the tubular wall 12 of the casing 10, is provided with elongate ribs 62 which extend parallel to the axis XX and which are received in a complementary manner in recesses 17 defined by the inner face of the tubular wall 12: a form-fitting between the ribs 62 and the notches 17, the nut 60 is movable only in translation in inside the room 1 1. Advantageously, the radial clearance between the ribs 62 and the notches 17 is provided sufficiently low that the cooperation between them guide the nut 60 relative to the casing 10 so as to align the nut on the axis XX.

In the assembled state of the cartridge 1, the screw 80 is screwed up, around the axis XX, in the nut 60, the screw 80 extending along the axis XX, of the interior of the chamber 1 1 to the outside of the envelope 10. the screw 80 thus includes a threaded portion 81 which, in the assembled state of the cartridge 1 is arranged inside the chamber 1 1 and is received screwed into the nut 60. in practice, the screwing-unscrewing cooperation between the nut 60 and the threaded portion 81 of the screw is relatively loose to allow the screw to be rotated in a flexible manner, avoiding any risk gripement at the interface between its threaded portion 81 and the nut 60. in this context, the nut 60 may be provided in plastic material, which increases the running clearance between the internal thread and the threaded portion 81 of the screw.

The screw 80 also includes an upper end portion 82, which is arranged outside the casing 10 and which is intended to be rotationally connected to a maneuver lever, not shown in the figures: for this purpose, this part terminal 82 is, for example splined, as clearly visible in figures 1 to 3. in addition, the screw 80 is locked in axial translation relative to the casing 10, and by any suitable means, non-limiting of the invention. Thus, in the assembled state of the cartridge 1, when the screw 80 is driven in rotation on itself about the axis XX from outside the envelope 10, including biasing the said maneuvering lever, the screw 80 causes the nut 60 in axial translation, and this downward or upward depending on the direction of rotation of the screw 80. the translation of the nut causes the translatory drive of the nozzle corresponding 50 and, then, the portion 32 of the thermostatic element 30, relative to the casing 10.

As is clearly visible in Figures 2 and 3, the screw 80 includes axially between its threaded portion 81 and its upper end portion 82, a part forming a bearing 83 which, in the assembled state of the cartridge 1 is arranged in a bore 18 of the casing 10 located at the upper end of this envelope. This bore 18 connects axially chamber 1 1 to the outside of the casing 10, thus allowing the screw 80 to extend from the inside of the chamber 1 1 to the outside of the casing 10 via this bore 18. the scope 83 of the screw 80 is received in the bore 18 so that, inside the bore 18, scope 83 is guided relative to the casing 10 so as to align the screw 80 on the axis XX. In the example in the figures, said guiding scope 83 is at least partially realized by an interposed seal 90 radially between the bearing 83 and the wall of the bore 18. This seal 90 is provided for both, compensate for radial play between the bearing 83 and the wall of the bore 18 and sealed chamber 1 1 in relation to the outside of the casing 10.

As is clearly visible in Figures 2 to 4, the screw 80 also includes a part forming a bearing 84, which is separate from the threaded portion 81 and the scope 83 and is arranged inside the room 1 1 being disposed out of the bore 18. This bearing 84 projects axially downwardly from the threaded portion 81 of the screw 80: in other words, the portion 81 is disposed axially between the bearing surfaces 83 and 84. at the inside the room 1 1 the scope 84 is guided relative to the casing 10 so as align the screw 80 on the axis XX, being received in a housing 53 of the nozzle 50: the housing 53 is provided adjusted radially to the scope 84 while allowing free relative mobility in axial translation between the housing and the range 84. Thus, in addition to the guidance provided by the cooperation between the bearing 83 and the wall of the bore 18, the screw 80 has a second guide formed between the scope 84 and the housing 53 of the tip 50, this second guide being readily obtained with a sliding fit between the bearing 84 and the housing 53. Accordingly, the amplitude of deflection of the screw 80 relative to the axis XX is severely limited: when is applied to the upper end portion 82 of the screw 80 a solicitation to tilt the screw relative to the axis XX, in particular by tilting at its scope 83 within the bore 18, this biasing is transmitted by the scope 84 to the nozzle 50 while the latter is rigidly connected to the nut 60 by the spring 70 and overtravel is adjusted radially to the nut by co-operation between the frustoconical surfaces 52 and 61. The rigid sub-assembly, formed by the end piece 50 and the nut 60 prevents the screw 80 to tilt radial support against the inner face of the tubular wall 12 of the nut and / or the tip 50, particularly the flange 51 thereof.

In Figure 6 is shown a thermostatic cartridge 101 whose components identical to those of the cartridge 1 have the same reference numbers. The cartridge 101 differs from the cartridge 1 by the screw 180.

Specifically, the screw 180 of the cartridge 101 has the same technical function as the screw 80 of the cartridge 1 and includes for this purpose a threaded portion 181, an end portion 182 and a first land 183, which are respectively similar to the part 81, the portion 82 and the scope 83 of the screw 80.

In addition, the screw 180 includes a bearing 184, which is separate from the threaded part 181 and scope 183 and which is different from the scope 84 of the screw 80. More precisely, as clearly visible in FIG 6, range 184 is, within the room 1 1 guided relative to the casing 10 so as to align the screws 180 on the axis XX, by a seal 102 interposed radially between the bearing 184 and the tubular wall 12 of the casing 10: this seal 102 is provided to compensate for radial play between the bearing 184 and the tubular wall 12. According to a practical and economical embodiment, the seal 102 is toric.

Compared with the cartridge 1, the guiding of the scope 184 of the screw 80, to align the latter on the axis XX, is not channeled through the nozzle 50 and / or nut 60, but is applied directly to the inner face of the tubular wall 12 by specifically on seal 102 for this purpose.

Following a compact arrangement, which is implemented in the embodiment of Figure 6, the range 184 is disposed axially between the threaded portion 181 and the scope 183 of the screw 180.

Moreover, as in the example of Figure 6, the range 184 is preferably constructed as a flange, projecting radially relative to the rest of the screw: this flange can then combine the alignment guide function for the screw 180, as described above, and a locking function of the screw in translation along the axis XX relative to the casing 10, the collar being for this purpose supported axially against a shoulder 19 of the casing, located the junction between chamber 1 1 and the bore 18.

In addition, various arrangements and variations to the cartridges 1 and 101 so far described are possible.

CLAIMS
1 .- Thermostatic cartridge (1; 101), comprising:
- a hollow casing (10) internally delimiting a chamber (1 1) which defines an axis (XX), within which run a cold fluid (F) and a hot fluid (C), and wherein a spell mixed fluid (M) resulting from the mixing of hot and cold fluids,

- a thermoelement (30) arranged in the chamber (1 1) and including both a first portion (31) which is heat sensitive and which flows the mixed fluid (M), and a second portion (32 ), which is axially displaceable relative to the first portion (31) and displaced by the first part so as to diverge from the first part during heating of the first portion,

- a return spring (40) which is interposed axially between the shell (10) and the thermostatic element (30) so as to bias the first (31) and second (32) parts of the thermostatic element the towards each other,

- a slide (20) which is movably mounted within the chamber (1 1) so as to control the respective amounts of cold fluid (F) and hot fluid (C) entering the chamber, and which is linked in axial translation to the first part (31) of the thermostatic element (30),

- a mouthpiece (50) which is arranged in the chamber (1 1) and against which is axially hold the second portion (32) of the thermostatic element (30) under the action of the return spring (40),

- a nut (60) which is mounted axially displaceable inside the chamber (1 1), while being connected in rotation about the axis (XX) in the casing (10),

- an overtravel spring (70) which is interposed axially between the end piece (50) and the nut (60) so as to, firstly, axially bind the cap and the nut rigidly as the axial displacement of the spool (20) by the first part (31) of the thermostatic element (30) relative to the casing (10) is free, and, on the other hand, to deform under the effect of the displacement the second axial portion (32) of the thermostatic element by the first part of the thermostatic element when the axial movement of the spool by the first part of the thermostatic element in relation to the casing is prevented, and

- a screw (80; 180) which is mounted around the screw axis (XX) in the nut (60) while being locked in axial translation relative to the casing (10), and which formed extends along the axis (XX) of the interior of the chamber (1 1) to the outside of the casing (10) via a bore (18) of the casing, the screw having a portion threaded (81; 181), which is received screwed into the nut, and a first bearing (83; 183) which is disposed in

the bore (18) and which, within the bore is guided relative to the casing so as to align the screw on the shaft,

characterized in that the screw (80; 180) further includes a second bearing (84; 184) which is separate from the threaded portion (81; 181) and the first bearing (83; 183) and which is arranged to inside the chamber (1 1), being disposed out of the bore (18), said second bearing surface being inside the chamber, guided relative to the casing (10) so as to align the screw on the axis (XX).

2. - Thermostatic cartridge (1) according to claim 1, characterized in that the second bearing surface (84) of the screw (80) is guided relative to the casing (10) so as to align the screw on the axis (XX), being received in a housing (53) of the endpiece (50) so that the second bearing surface of the screw is adjusted radially to the housing while being movable in axial translation in the housing, and in that the endpiece (50) and the nut (60) are fitted radially to one another when the overtravel spring (70) connected axially the mouthpiece and the nut to each other rigidly .

3. - Thermostatic cartridge (1) according to claim 2, characterized in that the end piece (50) and the nut (60) are fitted radially to one another by co-operation between the frustoconical surfaces (52, 61 ), which are delimited respectively by the cap and the nut and which are flared towards axially opposite the drawer (20), said frustoconical surfaces being adapted, in a reversible manner, to be applied one against the other under the Action of the overstroke spring (70) when the overtravel spring binds axially the mouthpiece and the nut to each other rigidly, and to disengage from one another when the spring overtravel is distorted.

4. - Thermostatic cartridge (1) according to one of claims 2 or 3, characterized in that the threaded portion (81) of the screw (80) is disposed axially between the first bearing (83) and the second bearing surface (84 ) of the screw.

5. Thermostatic cartridge (1) according to any one of claims 2 to

4, characterized in that the end piece (50) is provided with a collar (51) which is guided relative to the casing (10) so as to align the tip on the axis (XX), being received, with radial play, in a tubular wall (12) of the casing, this wall being centered on the axis (XX) and delimiting the chamber (1 1).

6. - Thermostatic cartridge (101) according to claim 1, characterized in that the second bearing surface (184) of the screw (180) is guided relative to the casing (10) so as to align the screw on the axis (XX) by a seal (102) that compensates a radial clearance between the second bearing surface of the screw and a tubular wall (12) of the casing, this wall being centered on the axis and delimiting the chamber (1 1 ).

7. - Thermostatic cartridge (101) according to claim 6, characterized in that the second bearing surface (184) of the screw (180) is disposed axially between the first bearing surface (183) and the threaded portion (181) of the screw.

8. - Thermostatic cartridge (101) according to one of Claims 6 or 7, characterized in that the second bearing surface (184) of the screw (180) forms a collar which is supported axially against a shoulder (19) of the casing (10), located at the junction between the chamber (1 1) and the bore (18).

9. - Thermostatic cartridge (101) according to any one of claims 6 to 8, characterized in that the seal (102) associated with the second bearing surface (184) is toric.

10. - Thermostatic cartridge (1; 101) according to any one of the preceding claims, characterized in that the first bearing (83; 183) of the screw

(80; 180) is guided relative to the casing (10) so as to align the screw on the axis (XX) by a seal (90) which, at the same time, compensates for a radial clearance between the first scope of the screw and a wall of the bore (18), and sealing the chamber (1 1) relative to the outside of the envelope.