FIELD OF INVENTION
The present invention relates to a cooling device.
This cooling device is advantageously applicable in an infrared vision device.
STATE OF THE ART
Are known infrared vision equipment, such as binoculars for example, to visualize targets at night or through fumes.
Such infrared vision equipment comprises an infrared detector and a cooling device (also called cooling machine or micro-cooler) for cooling the infrared detector, to a temperature typically of the order of 80 degrees Kelvin.

A cooling device for known infrared vision equipment, type Stirling alpha, comprises a housing, a movable handle to rotate relative to the housing, a coupling member rotatably mounted on the crank, and two pistons: a pressure piston gas, conventionally named piston "hot", and a regenerator piston, piston conventionally named "cold" in contrast to the hot piston.

A transformation of a crank of the continuous rotary motion relative to the housing into an alternating translational movement of the two pistons relative to the housing is implemented by means of two connecting rods. Each connecting rod is rotatably mounted on the coupling piece on the one hand and one of the other pistons, so as to form a conventional crank system.

However, the rods have the disadvantage of causing a large acoustic noise in the infrared vision equipment. This noise is caused by vibrations produced by backlash shocks at both pivot connections that form each link with one hand one of the two pistons and on the other with the coupling member, where efforts to change directions. This sound is unpleasant for a user of infrared vision equipment. Furthermore, infrared vision equipment often is intended to be used in tasks requiring great discretion. Or, a user of infrared vision equipment could be identified because of the large acoustic noise caused by the rod of this equipment. To avoid this noise problem

sound, it is necessary to reduce the games hinge joints to a few microns. However, this increases the cooling device manufacturing cost.

Another disadvantage of the link is that both hinge joints can wear or binding. To avoid these problems, it is necessary to have a perfect control on tribology parameters for the connecting rod and the two documents on which it is rotatably mounted to form the two pivot connections (lubrication, hardness, surface condition, etc. .). However, these requirements can not be met without increasing the cooling device manufacturing cost.

To overcome these issues without increasing the manufacturing cost of the cooling device, it has been proposed to replace the rod moving the compression piston by a deformable element. The deformable member is embedded on the one hand the piston and on the other hand to an edge of the coupling member which is located opposite the piston. The deformable element extends in its entirety between the coupling member and the compression piston. When the handle is brought into continuous rotation relative to the housing, the deformable element transmits to the piston, while deforming the reciprocating translatory motion undergone by the coupling member. By replacing one of the links by the deformable element,

However, a cooling device for infrared vision equipment must be as compact as possible. To meet this compactness requirements, the distance separating the piston and the coupling member is small compared to the piston stroke. This results in that the deformable element extending between the piston and the body is highly stressed in flexion during a turn handle, which significantly the fatigue.

It has been proposed in document FR3033630 fixed a deformable element not to a first edge of the coupling member which is located opposite the piston, but at a second edge opposite to the coupling member which is opposite to the first edge. The second edge is further from the piston than the first edge. Accordingly, the deformable element is longer than if it were recessed at the front edge of the coupling member. With this excess length, the deformable element is comparatively less decreased during a revolution of the crank. And as the deformable member is less loaded in bending, fatigue is lessened. This excess length of the deformable element is obtained without having to increase the distance between the piston and the crank. The size of the cooling device in parallel with the

However, the deformable element disclosed in FR3033630 is shaped L. This L-shaped armature necessarily a shift of the movable piston by the deformable member relative to the coupling member, and thus a shift of the central axis the piston with respect to the axis of rotation of the crank. This has the disadvantage of having to modify the shape of the housing and require a significant increase in the size of the device in a direction perpendicular to the translation axis of the piston.

DISCLOSURE OF INVENTION

An object of the invention is to provide a cooling device wear-resistant, while being inexpensive to manufacture, and generating a sound noise reduced without significantly increasing its size.

It is thus proposed, according to a first aspect of the invention, a cooling device comprising:

• a casing,

· A movable handle rotatably relative to the housing,

• A piston,

• a coupling element rotatably mounted on the crank, the coupling member having a first edge facing the piston and a second edge opposite the first edge,

· A deformable recessed member to the coupling member and fitted to the piston, the deformable element being configured for moving the piston translationally relative to the housing while being deformed, when the crank is rotated relative to the housing, the the deformable element being embedded in the second edge of the coupling member.

As the first edge of the coupling member faces the piston and that the second edge is opposite the first edge, the second edge is farther from the piston than the first edge. Accordingly, the deformable element is longer than if it were recessed at first side of the coupling member, as is proposed in the prior art. With this excess length, the deformable element is comparatively less decreased during a revolution of the crank. And as the deformable member is less loaded in bending, fatigue is lessened. This excess length of the deformable element is obtained without having to increase the distance between the piston and the crank. The size of the cooling device parallel to the axis of translation of the piston n '

In addition, the deformable member comprises:

• a first portion extending along the second edge of the body parallel to an axis of rotation of the crank,

• a second portion extending the first portion and extending towards the piston,

• a third portion extending the second portion and extending parallel to the axis of rotation of the crank, so that the three portions form a U straddling the coupling member.

This particular shape deformable element has the advantage of not requiring a significant increase in a dimension of the cooling device in a direction perpendicular to the axis of translation of the piston.

Another advantage afforded by this particular shape deformable element is that it is readily adaptable to existing cooling devices in which the axis of translation of the piston and the axis of rotation of the crank are coplanar.

The cooling device may further include the following optional features, taken alone or in combination where technically possible.

The deformable element may have a shape adapted to bypass the coupling member without touching the first edge during the rotation of the crank relative to the housing.

It can further be provided that:

· The handle comprises a drive shaft and an eccentric crank pin with respect to the motor shaft,

• the coupling member is rotatably mounted on the crank pin, and is located between the second portion of the coupling member and the motor shaft.

The deformable element may be rounded and / or leave at least one junction between two portions.

The crank may include a pin and the coupling member comprise a first wall wherein the first edge is formed and a second wall wherein the second edge is formed, the crank pin being arranged between the two walls.

The deformable member may be made of metal.

The deformable member may be a sheet or a blue sheet gauges.

The deformable element may comprise an end portion having a first orifice and the piston have: a groove for receiving the end portion, two holes opening into the groove and arranged to be aligned with the first orifice, and a pin passed through the three aligned holes for embedding the deformable member to the piston.

The cooling device may further comprise

• a nut formed in the coupling member,

• a clean screw to cooperate with the deformable member and the nut so as to embed the deformable element to the coupling member.

Furthermore, the housing may define a cavity accommodating the coupling member, and further has an access passage to the cavity, and the nut can be oriented access facing the passage such that the screw can be screwed into the nut by means of a screwing tool introduced into the cavity via the access passage.

The cooling device may be of the Stirling type alpha, in which case the piston may be a cold piston of the cooling device.

The cooling device may further comprise:

• a second piston,

• a second deformable member recessed in the coupling member and fitted to the second piston, the second deformable member being configured to move the second piston in translation relative to the casing while being deformed, when the crank is rotated relative to casing.

The coupling member may also have a third edge opposite the second piston, wherein the second deformable element is clamped to the third edge of the coupling member.

When the cooling device is of the Stirling type alpha, the second piston may be a hot piston of the cooling device.

The cooling device can be especially designed to be embedded in an infrared vision device.

According to a second aspect of the invention there is provided an infrared vision device, such as binoculars, comprising a cooling device according to the first aspect of the invention.

DESCRIPTION OF FIGURES

Other features, objects and advantages of the invention will become apparent from the following description, which is purely illustrative and not exhaustive, and should be read in conjunction with the accompanying drawings wherein:

• Figure 1 is a schematic view of binoculars to infrared vision, according to one embodiment of the invention.

• Figure 2 is a view in partial section of a cooling device, according to one embodiment of the invention.

• Figure 3 is a perspective view of a housing of a cooling device according to an embodiment of the invention.

• Figure 4 is a partial sectional perspective view of a cooling device according to a first embodiment of the invention.

"Figure 5 is a perspective view of certain parts of the cooling device according to the first embodiment.

• Figures 6 and 7 are two perspective views of a first deformable element of the cooling device according to the first embodiment, respectively in a non-deformed state and in a deformed state.

"Figure 8 is a perspective view of the first deformable member shown in Figures 6 and 7 and other parts of the cooling device to which this deformable member is embedded.

• Figure 9 is a perspective view of a second deformable member of the cooling device according to the first embodiment.

"Figure 10 is a partial perspective view of the second deformable member shown in Figure 9 and a coupling member of the cooling device of Figure 5.

• Figure 1 1 is a partial sectional perspective view of the second deformable member shown in Figure 9 and a piston of Figure 5 the cooling device.

• Figure 12 is a perspective view of parts of a cooling device according to a second embodiment of the invention.

• Figure 13 is a perspective view of parts of a cooling device according to a third embodiment of the invention.

Of all the figures, similar elements bear identical references.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 schematically illustrates one of infrared vision goggles. Binoculars 1 comprise a housing 2, an optical system 3, an infrared detector 4, a processing module 5 and two screens display 6. The optical system 3 has an optical axis Y. The optical system 3 is arranged to transmit a infrared radiation emitted by a target detection unit 4. the sensor unit 4 converts the received infrared radiation to a detection signal which is transmitted to the processing unit 5. the processing unit 5 controls the display of an image on the display screen 6 for allowing a user to view the target. To this end, the user positions his eyes in front of the screens display 6.

Binoculars Other facilities include a cooling device 8. In the present text, the term "cooling device" is to be interpreted as any thermal machine configured to produce cold (such as a cold machine, cooler, microwave -refroidisseur, etc.). The cooling device is operable to maintain the temperature of the infrared detector to a very low temperature, of the order of 80 degrees Kelvin.

Referring to Figure 2, the cooling device 8 according to a first embodiment comprises a compression cylinder 10 having a central axis X, and a compression piston 12 movable in translation along the X axis in the compression cylinder 10 . the compression chamber 13 is defined by the compression cylinder 10 and the compression piston 12.

The compression piston 12 is operable when moved in translation, to compress or relax a gas in the compression chamber 13.

The cooling device 8 further comprises a regeneration cylinder 14 having as axis the central axis Y and a regenerator piston 16 mobile in translation along the axis Y in the regeneration of cylinder 14. The regeneration cylinder 14 is formed e.g. in a cold finger.

The optical system 3, the detector 4 and the cold finger 14 are coaxial and arranged in this order along the Y axis

The expansion chamber 17 is defined by the regeneration of cylinder 14 and the regenerator 16. The regenerator piston piston 16 has the function, when it is moved in translation in the cylinder to compress or relax a gas in the chamber expansion 17.

The cooling device 8 comprises a conduit 18 connecting the compression chamber 13 to the expansion chamber 17.

The cooling device 8 further comprises a regenerator 20, arranged in the expansion chamber 17. The regenerator 20 is a hollow body adapted for storing a part of heat energy of a gas which passes through it when the piston compression 12 compresses the gas in the compression chamber 13 and then return this energy in a gas expansion into the expansion chamber 17, caused by a displacement of the regenerative piston 16.

The regenerator piston 16 is fixed to the regenerator 20, or forms a part of the regenerator 20.

The cooling device 8 is Stirling alpha. As a reminder, a Stirling cycle includes four phases:

• An isothermal compression phase, during which the gas in the compression chamber 13 is compressed by the compression piston 12 away from the central cavity.

• A phase isochoric cooling, during which the compressed gas is transferred from the compression chamber 13 to the expansion chamber 17 via line 18. The gas yields part of its heat energy to the regenerator 20, where the cross-member. The drop in temperature is then brought causes a pressure drop.

• A phase expansion isotherm, in which a displacement generated by the regenerator piston 16 toward the central cavity. The pressure drop causes the cooling of the gas in the expansion chamber 17.

• A phase of isochoric warming, during which the gas passes to the expansion chamber 17 to the compression chamber 13 via line 18. through the regenerator 20, gas recovers heat that is transferred during the isochoric cooling phase.

The compression piston 12 is called piston "hot" and the regenerator piston is called piston "cold." These two terms, well known to those skilled in the art, refer to the fact that the gas in the compression chamber 13 is warmer than in the expansion chamber 17.

We will now describe the means of movement of the pistons 12 and 16 that can implement the Stirling cycle.

Referring to Figure 3, the cooling device 8 comprises a housing 22 defining a central cavity 24.

The compression cylinder 10 opens into the central cavity 24. The compression cylinder 10 is at least partially formed by the housing 22. Similarly, the cylinder 14 opens regeneration in the central cavity 24, and is partly formed by the casing 22.

However, the pipe 18 connects the compression chamber 13 to the expansion chamber 17 without passing through the central cavity 24.

The housing 22 defines an access passageway 26 to the central cavity 24, which extends along a third axis Z. The axes X, Y, Z are orthogonal two by two. They pass through the same center point located in the central cavity defined by the housing 22.

Referring to Figure 4, the cooling device 8 comprises a handle 28 configured to be rotated about the axis Z.

The crank 28 is rotated by a motor, eg an electric motor (not shown in the figures). The motor is typically disposed outside of the central cavity 24, a part of the generator is located between the processing module 5 and the central cavity 24, this part being visible in figure 1.

The crank 28 comprises a motor shaft 30 extending in the access passage 26 in the central cavity 24.

A first end of the motor shaft 30 is rotatably mounted on the engine. A second end of the motor shaft 30, opposite the first end, extends into the central cavity 24 or in the vicinity thereof.

The drive shaft 30 is rotatable about the axis Z. The drive shaft 30 has for example a circular end surface.

The crank 28 also comprises a crank pin 32 fixed to the end of the nearest motor shaft of the central cavity 24. The crankpin 32 has a shape of revolution about an axis Z 'parallel to the axis Z but away from it. The crank pin 32 is therefore caused to move in orbit around the Z axis, during the rotation of the shaft motor 30.

The crank pin 32 is located in the central cavity 24. The crankpin 32 has a typically cylindrical outer surface of revolution.

cooling device 8 further comprises a coupling member 34 rotatably mounted on the crank 28.

More specifically, the coupling member is rotatably mounted on the crankpin 32 of the crank 28 around the axis Z '.

The coupling member 34 has a radially inner surface 36. The radially inner surface 36 defines an internal space in which the crank pin 32 is received. The coupling member 34 thus extends about the axis of the crankpin 32.

The inner diameter of the radially inner surface 36 of the coupling member 34 is larger than the outer diameter of the crank pin 32, so that an annular gap 38 is formed between the outer surface of the crankpin 32 and the inner surface 36 of the member 34.

Referring to Figure 5, a ball bearing system 40 is arranged in this annular gap 36.

The coupling member 34 includes a first wall 42 and second wall 44. The pin 32 extends between the first wall 42 and second wall 44.

The coupling member 34 further comprises a third wall 46 and a fourth wall 48. The pin 32 extends between the third wall 46 and fourth wall 48.

The third wall 46 and fourth wall 48 each connect the first wall 42 to second wall 44. In other words, the four walls 42, 44, 46, 48 are set around the crank pin 32 about its axis Z '.

The coupling member 34 comprises a first free edge 50 opposite the plunger 12, and a second free edge 52 opposite the first edge 50 with respect to the crank pin 32. The first free edge 50 is formed in the first wall 42, and the second free edge 52 is formed in the second wall 44.

The coupling member 34 comprises a third edge 54 facing the regenerative piston 16, and a fourth edge 56 opposite to the third edge 54 with respect to the crank pin 32. The third free edge 54 is formed in the third wall 46 and the fourth free edge 56 is formed in the fourth wall 48.

The third free edge 54 and the fourth free edge 56 each connect the first edge 50 to second edge 52.

The four free edges 50, 52, 54, 56 together form a portion of the outer member of the coupling surface 34, closed on itself and extending around the crank pin 32. The four edges 50, 52, 54, 56 define four sides of the coupling member 34 seen in a sectional plane perpendicular to the motor axis Z.

The coupling member 34 further has a fifth edge 58 opposite the drive shaft 30, and a sixth edge 60 opposite the fifth edge 58.

The fifth and sixth edge 58 edge 60 each connect the inner surface to the outer member of the coupling surface 34.

The cooling device comprises a first deformable member 62 configured to transmit the compression piston 12 while deforming a reciprocating translatory motion undergone by the coupling member 34 when the crank 28 is brought into continuous rotation relative to the housing 22 about the axis Z.

The cooling device further comprises a second deformable member 64 configured to transmit to the regenerator piston 16, while deforming a reciprocating translatory motion undergone by the coupling member 34 when the crank 28 is brought into continuous rotation with respect to housing 22.

Referring to Figures 6 and 7, the first deformable member 62 has a first end portion 66 recessed in the coupling member 34, and a second end portion 68 opposite the first end portion 66, recessed in compression piston 12.

The first deformable member 62 has further an intermediate portion 70 connecting the first end portion 66 to the second end portion 68.

The first deformable member 62 is a metal sheet. By sheet is meant in this text that the first deformable member 62 has a thin thickness compared to its length and width.

In an undeformed configuration, the first deformable member 62 is substantially flat.

The first deformable member 62 has two opposite faces 72 and 74, the thickness of the first deformable member 62 being measured perpendicularly to the two faces.

In an undeformed configuration, the two opposite faces 72 and 74 are planar. The first deformable member 62 then has a rectilinear profile in a plane perpendicular to the two plane faces (the thickness of the first deformable member 62 close).

The two flat faces 72, 74 are rectangular.

A first orifice 76 is formed in the first end portion 66, and a second orifice 78 is formed in the second end portion 68. The two holes 76, 78 each open into the two opposite faces 72 and 74.

The first deformable member 62 is interlocked to compression piston 12 and the coupling member 34 so that at least a position of the coupling member 34 relative to the housing 22 during a turn the crank 28, wherein the first deformable member 62 is in its undeformed configuration.

More specifically, as shown in Figure 6, the first deformable member 62 is interlocked to compression piston 12 and the outer member of the coupling surface 34 in appropriate positions so that the first deformable member 62 can be traversed on its entire length by the plane formed by the Z axis motor and the compression axis X (therefore not deformed in flexure) when:

· The crank pin 32 occupies a position closest to the plunger 12 during a revolution of the crank 28,

• the crankpin 32 is in a distal position of the compression piston 12 during a turn of the crank 28.

The first deformable member 62 is of a flexibility adapted to enable it to adopt an S-shaped profile in a plane perpendicular to the motor axis, when the axis of crank pin 32 is not in the plane defined by motor axis Z and the axis X of compression, as seen in Figure 7.

However, the first deformable member 62 has an axial stiffness (measured parallel to the axis X) adapted to allow it to transmit motion to

reciprocating translation of the crankpin 32 to the compression piston 12 even when it is deformed and has the shape of an S.

This is the first edge 50 of the coupling member 34 (located opposite the pressure piston 12) than the first end portion of the first deformable member 62 is fixed, and only thereto. The first deformable member 62 is located between the compression piston 12 and the crank pin 32 of the crank 28, whatever the position of 32 relative to the casing 22 crankpin.

Referring to Figure 8, to embed the first deformable member 66 to the coupling member 34, the first port 76 is aligned with a hole formed in an element of the coupling member projecting from the first wall toward the piston 12. a compression wedge 80 having another orifice is positioned such that its orifice is aligned with the holes, and whereby the first end portion 76 is sandwiched between the protruding member and the wedge. A screw-nut system 82 is used to encase the first portion of the first deformable member 62 to the coupling member 34. This system comprises a screw which is passed through the three orifices. The nut co-operates with the screw so as to maintain the latter in through the three orifices.

Similarly, the second port 78 is aligned with a hole in an element projecting from the plunger 12 toward the first wall of the coupling member 34. A wedge 84 having another orifice is positioned such that its orifice is aligned with the holes, and whereby the second end portion 68 is sandwiched between the protruding element of the piston 12 and the wedge 84. A screw-nut system 86 is used to embed the second end portion of the first deformable member 62 to the coupling member 34. This system comprises a screw which is passed through the three orifices. The nut co-operates with the screw so as to maintain the latter in through the three orifices.

The first deformable member 62 is for example made of blue steel gauges.

This denomination, known to the art, including covers unalloyed structural steel XC70. This steel has the advantage of having a good tensile strength (about 1080 MPa) useful for the mechanical strength of the first deformable member 62.

The blue sheet sizes present the advantage of having a very significant yield and excellent fatigue limit, while having a low Young's modulus not to require too much effort during its deformation. The use of such a material to make the first deformable member 62 is therefore particularly advantageous.

For example, the first deformable member 62 has a thickness of 0.25 millimeters, a length of 15 millimeters, and a width of 6.25 millimeters.

Furthermore, the Young's modulus of the first deformable member 62 along the axis of compression is preferably from 210 000 MPa.

The first deformable element is typically manufactured by chemical cutting. Referring to Figure 9, the second deformable member 64 has a first end portion 88 recessed in the coupling member 34, and a second end portion 90 opposite the first end 88 recessed to the regenerator piston 16.

The second deformable member 64 has two faces 92, 94 opposing, the thickness of the deformable element 64, measured perpendicularly to the two faces 92, 94 is small compared to its length and its width.

The second deformable member 64 is recessed to the regenerator piston 16 and the coupling member 34 so that at least a position of the coupling member 34 relative to the housing 22, during one revolution of the crank 28 wherein the second deformable member 64 is in an undeformed configuration.

Specifically, the second deformable member 64 is recessed to the regenerator piston 16 and the outer member of the coupling surface 34 in appropriate positions so that the deformable element can be traversed over its entire length by the plane formed by the motor axis and the axis of regeneration (therefore not deformed in flexion) where: • the crank pin 32 occupies a position closest to the regenerator piston 16 during a turn of the crank 28,

· The crankpin 32 is in a farthest position from the regenerator piston 16 during a turn of the crank 28.

The second deformable element 64 is a suitable flexibility to enable it to adopt an S-shaped profile in a plane perpendicular to the motor axis Z, when the axis of crank pin 32 is not in the plane defined by the Z axis motor and the axis of regeneration Y.

Nevertheless, the second deformable member 64 has an axial stiffness (measured parallel to the axis of regeneration Y) which is adapted to enable it to transmit a reciprocating translational movement of the crank pin 32 to the regenerator piston 16 even when it is deformed and he has this form of S.

The second deformable element 64 is for example made of the same material as the other deformable member, for the same reasons.

The second deformable element 64 is for example produced by chemical machining. This method has the advantage of being inexpensive and especially suitable for thin parts and relatively fragile.

The second deformable element 64 is a sheet.

For example, the second deformable member 64 has a thickness of 0.25 millimeters, a length of 1 5 mm, and a width of 6.25 millimeters.

Furthermore, the Young's modulus of the deformable member along the axis of compression is preferably from 210 000 MPa.

However, the shape of the second deformable member 64 is different from that of the first deformable member 62, and the place of installation of the second deformable member 64 to the coupling member 34 is also different from the first deformable member 62.

It is the fourth edge 56 of the member 34 as coupling the first end portion of the deformable element is fixed, and only thereto. In particular, the deformable member is not fixed to the third edge 54 opposite the regenerator piston 16.

The second deformable member 64 has a shape adapted to bypass the coupling member 34 and the crankpin 32.

In addition, the two opposite faces 92 and 94 are not rectangular.

The second deformable element 64 has the following portions (in addition to its two end portions 88, 90):

• a first intermediate portion 96 extending the first end portion 88, the first intermediate portion 96 extending from the fourth edge 56, parallel to the Z-axis motor,

• a second intermediate portion 98 extending the first intermediate portion 96, opposite the sixth edge 60, and extending to the regenerator piston 16, parallel to the axis Y of regeneration,

• a third intermediate portion 100 extending the second intermediate portion 98 and extending parallel to the axis motor Z, so that the three portions 96, 98, 100 together form a U overlapping the coupling member 34. Due to the fact that the second intermediate portion 98 is arranged opposite the sixth edge 60, the coupling member 34 is located between the second portion is the motor shaft 30. the bypass the coupling member 34 by the deformable element is thus facilitated since the deformable member is not impeded by the drive shaft 30 during a revolution of the crank 28.

The second deformable element 64 comprises, at the junction between the portions 96 and 98 leave and / or rounded.

The second deformable element 64 further comprises, at the junction between the portions 98 and 100, leave and / or rounded.

The second deformable element 64 further comprises, at the junction between the portions 100 and 90, leave and / or rounded.

Each rounded off or has the effect of avoiding the stress concentration in the second deformable member 64, when the latter is deformed in bending.

The first portion 88 end of the first deformable member 62 has an orifice 102, and the second end portion 90 has an orifice 104. The orifices 102, 104 each open into the two opposite faces 92 and 94.

Referring to Figure 10, to embed the second deformable member 68 to the coupling member 34, the first port 102 may be aligned with a nut 108 formed in an element of the coupling member projecting from the fourth wall 48 . this nut is formed by a threaded hole in the element. A screw 106 is passed through the orifice 102 and the nut 108 aligned.

Preferably, the nut 108 and the screw 106 are arranged so that the axis of screwing of the screw in the nut is parallel to the motor axis Z of the crank 28 and is oriented so that the screw can be screwed in the nut by means of a screwing tool inserted into the access passage 26 in the central cavity 24. such an arrangement makes it easier to remove and replace the second deformable member 64. for example, the first portion of end 88 is bent at 90 degrees with respect to the intermediate portion 96. of course, other engagement means of the second deformable member 68 to the coupling member 34 may be used instead of the orifice 10 and a screw-nut system.

Moreover, the second intermediate portion is inserted into a gap formed between the element in which the nut is formed and another element projecting from the fourth wall of the coupling member 34, as shown in Figure 10 .

The second port 104 of the second deformable element is also engaged in a groove formed in the regenerator piston 16 so that the orifice 104 is disposed between and aligned with two transverse holes opening into the groove (typically 0.6 mm diameter ). A pin is passed through the three aligned holes, to embed the second deformable member 64 to the regenerator piston 16. Alternatively, other fitting means of the second deformable member 68 to the regenerator piston 16 can be used, for example by gluing , without using a pin.

The means for moving the pistons 12 and 16 are mounted in the cooling device 8 according to the following method.

First, the second deformable member 64 is recessed to the regenerator piston 16, and the regenerative piston 16 is fixed to the regenerator 20 so as to form a first set of parts.

Second, the first deformable member 62 is clamped to the coupling member 34 and the pressure piston 12 so as to form a second set of parts.

Thirdly, the two sets of parts are assembled by fitting the second deformable member 64 to the coupling member 34.

Fourth, the drive shaft 30 is inserted through the access passage 26 in the cavity 24 so that the pin 32 engages in the coupling piece 34.

The cooling device 8 operates as follows.

When the motor is energized, it rotates the motor shaft 30 of the crank 28 about the axis Z. The crank pin 32 itself rotates about the axis Z, being integral with the motor shaft 30 as well as the coupling member 34 extending around the pin 30.

During a revolution of the crank 28, the coupling member 34 moves in translation and in rotation simultaneously.

First, the coupling member 32 carries with it the first deformable member 62 so that the latter moves the compression piston 12 in rectilinear translation along the X axis, while being deformed flexurally.

Simultaneously, the coupling member 32 carries with it the second deformable element 64, so that the latter moves the regeneration of piston 16 in rectilinear translation along the Y axis while being deformed flexurally. It should be noted that the second deformable member 64 is longer than if it were recessed to the first edge 50 of the coupling member 34, opposite the regenerator piston 12. With this excess length, the deformable element 64 is somewhat flexed during a revolution of the crank 28, slowing down its wear.

Simultaneously, the coupling member undergoes a slight reciprocating rotary motion relative to the housing 22. This rotation is limited by the axial stiffness of the two deformable elements 62 and 64. Accordingly, the edge 50 of the coupling member 34 remains constantly facing the compression piston 12 and the edge 54 of the coupling member 34 remains constantly facing the regenerative piston 16, during a revolution of the crank 28.

Once a turn crank completed, a thermal cycle of the cooling device 8 is completed.

In the first embodiment described above, one of the two deformable elements 62 and 64 which the U-shape bypasses the coupling member is advantageously the second deformable member 64 interlocked to the regenerator piston, and this for the following reasons. As indicated above, this U-shape allows

to ensure that the deformable element is slightly flexed in a Stirling cycle. However, the U-shape is relatively fragile. As the forces on the regenerator piston are smaller than on the piston "hot" compression, it is preferable that the deformable element 64 which has such a U-shaped

Other cooling device embodiments can be considered.

Figure 12 for example shows a second cooling device of embodiment differing from the first embodiment in that the second deformable member 64 bypassing the coupling member 34 is replaced by a deformable element 65 through the body of the cutting member 34. the second deformable member 65 extends in particular through a passage formed in the third wall 46 (the one closest to and facing the regenerative piston 16, and in which is formed the edge 54), and otherwise through another passage formed in the fourth wall 48 opposite the wall 46 (and in which the edge 56 is formed).

Figure 13 shows a third embodiment of the cooling device of embodiment which differs from the first embodiment by the features relating to the embedding of the deformable element 64 to the coupling member 34. The end portion 88 of the deformable element 64 is not bent at 90 degrees to the rest of the deformable member 64. Furthermore, the wedge 80 is replaced by two wedge members 81, 83. the screw 106 passes through the first element of wedge 81 then the nut 108 formed in the coupling member 34. the second wedge member 83 is arranged to rest against the end portion 88 of the deformable member 64. the two wedge elements 81 and 83 are of shapes adapted to a screwing of the screw parallel to theZ-axis motor drives a load on the first wedge member 81 the second wedge member along an axis perpendicular to the axis Z (parallel to the X axis), and consequently a request from the second wedge member 83 against the end portion of the deformable element 64. such biasing can be achieved by giving the two spacer members a bevelled shape.

Furthermore, the two deformable elements of each of the previously described embodiments can be interchanged within the cooling device 8.

CLAIMS

1. A cooling device (8) comprising:

• a housing (22),

· A crank (28) rotatable relative to the housing (22),

• a piston (16),

• a coupling member (34) rotatably mounted on the crank (28), the coupling member (34) having a first edge (54) facing the piston (16) and a second edge (56) opposite the first edge (54),

"A deformable element (64) recessed in the coupling member (34) and interlocked to piston (16), the deformable element (64) being configured to move the piston (16) translationally relative to the housing while deforming, when the crank (28) is rotated relative to the housing (22),

the cooling device (8) being characterized in that the deformable element (64) is embedded in the second edge (56) of the coupling member (34), and in that wherein the deformable member (64) comprises :

• a first portion (96) extending along the second edge (56) of the body parallel to an axis of rotation of the crank (28),

• a second portion (98) extending the first portion (96) and extending towards the piston (16),

• a third portion (100) extending the second portion (98) and extending parallel to the axis of rotation of the crank (28) so that the three portions (96, 98, 100) form a U overlapping the the coupling member (34).

2. A cooling device (8) according to the preceding claim, wherein the deformable member (64) has a shape adapted to bypass the coupling member (34) without touching the first edge (54) during the rotation of the crank (28) relative to the housing (22).

3. A cooling device (8) according to one of the preceding claims, wherein the handle is rotatable relative to the housing (22) about an axis of rotation (Z) and the piston is movable in translation along a translation axis (Y) coplanar with the axis of rotation (Z).

4. A cooling device (8) according to one of the preceding claims, wherein • the crank includes a motor shaft (30) and an eccentric crank pin with respect to the motor shaft (32),

• the coupling member (34) is rotatably mounted on the crankpin (32) and is located between the second portion (98) of the deformable element (64) and the motor shaft (30).

5. Cooling device according to one of the preceding claims, wherein the deformable member (64) has a rounded and / or leave at least one junction between two portions (96, 98, 100).

6. A cooling device (8) according to one of the preceding claims, wherein the crank (28) comprises a crankpin (32), and wherein the coupling member (34) comprises a first wall (46) wherein the first edge (54) is formed, and a second wall (48) wherein the second edge (56) is formed, the crank pin (32) being arranged between the first and second walls (46, 48).

7. A cooling device (8) according to one of the preceding claims, wherein the deformable member (64) is metal.

8. A cooling device (8) according to one of the preceding claims, wherein the deformable member (64) is a metal sheet, for example a blue steel gauges.

9. A cooling device (8) according to one of the preceding claims, wherein:

• the deformable element (64) comprises an end portion (90) having a first port (104),

· The piston (16) has a groove for receiving the end portion (104), two orifices opening in the groove and arranged to be aligned with the first port (104), and a pin passed through the three aligned holes for Built the deformable element (64) to the piston (16).

10. A cooling device (8) according to one of the preceding claims, comprising

• a nut formed in the coupling member (34),

• a clean screw to cooperate with the deformable element (64) and the nut so as to embed the deformable element (64) to the coupling member (34).

January 1. cooling device (8) according to the preceding claim, wherein

• the housing (22) defines a cavity (24) accommodating the coupling member (34), and further has an access passage (26) to the cavity (24),

• the nut is oriented opposite the access passage (22) so that the screw can be screwed into the nut by means of a screwing tool introduced into the cavity via the access passage (26).

12. A cooling device (8) according to one of the preceding claims, alpha Stirling type, and wherein the piston (16) is a cold piston of the cooling device (8).

13. A cooling device (8) according to one of the preceding claims, further comprising:

• a second piston (12),

• a second deformable member (62) recessed in the coupling member (34) and interlocked to second piston (12), the second deformable member (62) being configured to move the second piston (12) translationally relative to the housing (22) while being deformed, when the crank (28) is rotated relative to the housing (22).

14. A cooling device (8) according to the preceding claim, wherein the coupling member (34) also has a third edge (50) facing the second piston (12), and wherein the second deformable member (62) is embedded in the third edge (50) of the coupling member (34).

15. A cooling device (8) according to one of claims 13 to 14, Stirling alpha type, and wherein the second piston (12) is a hot piston of the cooling device (8).

16. The device of infrared vision (1), for example binoculars, comprising a cooling device (8) according to one of the preceding claims.