Kinematic reduction position adjustment device

Abstract

A device (1) for adjusting the position of a space equipment is described, comprising: an actuator (10) for generating a movement along an axis (XX), a kinematic reduction stage (20) comprising an interface (201) for joining to the equipment, comprising: two input arms (21) of the reduction stage, articulated with each other at a second interface for joining with the actuator, two external arms (22) articulated with the frame (19) and with the two input arms, two internal arms (24) articulated at the junctions between the external arms and the input arms and with an interface arm (23) arranged transversely to the axis, the reduction stage being dimensioned so that a movement of the interface with the actuator along the axis causes a movement of the interface arm, in the same direction and according to a reduced amplitude of a reduction ratio which is a function of the relative lengths of the arms. Abstract Figure: Figure 1

Description

Title of the invention: Kinematic reduction position adjustment device Technical field

[0001] The present disclosure relates to a device for adjusting the position of equipment, in particular space equipment such as a telescope mirror, a prism or a radiofrequency antenna. Prior art

[0002] To be able to finely adjust the position of a piece of equipment, for example to be able to orient a space telescope with great precision, it is known to use mechanisms comprising an actuator, and a stage for reducing the movement generated by the actuator. The reduction stage makes it possible to provide a significant kinematic reduction ratio between an input movement, generated by the motor or a geared motor, and an output translation movement, which is connected to the equipment and therefore makes it possible to orient this equipment.

[0003] For example, from document US 5,969,892, and from the publication by Robert M. Warden, "Cryogenic Nano-Actuator for JWST", in Proceedings of the 38th Aerospace Mechanisms Symposium, Langley Research Center, May 17-19, 2006, a device is known for adjusting the position of an instrument, comprising side walls of which an intermediate portion is thinned, and connected to a transverse wall of which a thinned middle portion is connected to the actuator, and therefore moved in translation by the translational movement generated by the actuator. A second transverse wall, superimposed on the first, is connected to the upper ends of the side walls, and also connected to the instrument.The deformation of the transverse wall under the effect of the translation of its middle portion induces a deformation of the side walls, and consequently a displacement of the second transverse wall, and therefore of the instrument, with a reduction ratio between the displacement of the second transverse wall compared to the displacement of the first transverse wall.

[0004] This equipment makes it possible to obtain a very fine resolution, the resolution being defined as the translation of the instrument for one step of the stepper motor of the actuator, since this resolution is 7 nm per motor step. However, the travel allowed by this device is limited since it is only 10 pm, the travel being defined as the maximum distance traveled by the instrument at the level of the second transverse wall.

[0005] Also known from the document by E. Urgoiti et al. “Gaia M2M Positioning Mechanism » a device for adjusting the positioning of a secondary mirror of the GAIA telescope, also comprising a structure of flexible blades, one blade of which is driven in translation by an actuator, being connected to an opposite blade by flexible lateral blades, thus driving in translation the opposite blade connected to the instrument. This device has a resolution of 0.2pm and a stroke of 400pm.

[0006] However, certain applications require higher performance in terms of resolution and travel, namely a resolution of the order of a nanometer, and in any case less than 30 nm, with in addition a travel of several hundred microns. The devices presented above do not provide satisfaction with regard to these constraints. Summary

[0007] The present disclosure improves the situation.

[0008] In particular, an aim of the present disclosure is to propose a device having a resolution of less than 30 nm and a travel of several hundred microns.

[0009] Another aim of the present disclosure is to propose a device whose kinematic behavior is invariant as a function of temperature.

[0010] Another aim of the present disclosure is to propose a robust device, capable of withstanding significant forces, particularly for space applications in which the device is launched into space.

[0011] In this regard, there is provided a position adjustment device suitable for space equipment, comprising: - an actuator fixed on a support frame adapted to generate a translational movement along a central axis, and - a kinematic reduction stage fixed to the frame and comprising a first interface for junction with the equipment, characterized in that the kinematic reduction stage comprises: - two arms at the input of the reduction stage articulated with each other at a second junction interface with the actuator, the two arms at the input of the reduction stage forming an obtuse angle between them, - two external lateral arms articulated on the one hand with the frame and on the other hand with the two arms at the entrance of the reduction stage and - two internal lateral arms articulated on the one hand at the junctions between the external lateral arms and the arms at the input of the reduction stage and on the other hand with an interface arm arranged transversely to the central axis to form the first junction interface to the equipment, each internal lateral arm forming an acute angle with one of the arms at the input of the reduction stage and with one of the external side arms, the kinematic reduction stage being dimensioned so that a displacement of the second junction interface with the actuator along the central axis, in one direction and according to an amplitude causes a displacement of the interface arm along the central axis, in the same direction and according to said amplitude reduced by a reduction ratio which is a function of the relative lengths of the arms belonging to the kinematic reduction stage.

[0012] In embodiments, the input arms of the reduction stage and the external side arms form an M-shaped profile.

[0013] In embodiments, the projection, on the central axis, of the articulations of the external lateral arms with the frame is arranged between on the one hand the second junction interface with the actuator and on the other hand a central portion of the interface arm.

[0014] In embodiments, when considering the projection, on the central axis, of the articulations of the external lateral arms with the frame, a distance taken between this projection and the second junction interface with the actuator is greater than twice a distance taken between this projection and the central portion of the interface arm.

[0015] In embodiments, the arms, belonging to the kinematic reduction stage, which end in articulations, are each constituted by a blade of which portions at its two ends have a reduced thickness.

[0016] In embodiments, the kinematic reduction stage has a plane of symmetry, the central axis being arranged in this plane of symmetry.

[0017] In embodiments, the internal lateral arms are inclined relative to the central axis, so that their end connected to the interface arm is closer to the central axis than their end connected to the junction between one of the external lateral arms and one of the arms at the input of the reduction stage.

[0018] In embodiments, the length of the outer side arms is strictly less than the length of the inner side arms.

[0019] In embodiments, the interface arm is further connected to the frame by a flexible blade extending perpendicular to the interface arm and perpendicular to the central axis.

[0020] In embodiments, the inner side arms, the interface arm, the outer side arms and the input arms of the reduction stage are made of a single material.

[0021] In embodiments, the device further comprises holding and releasing equipment adapted to temporarily hold the interface arm or the external side arms.

[0022] According to another object, there is also described an assembly, comprising at least one optical or radiofrequency spatial equipment and at least three devices according to the preceding description, for an adjustment of the position, at at least three points, of each space equipment.

[0023] In embodiments, the spatial equipment is optical equipment in the form of a prism or a mirror.

[0024] In embodiments, the space equipment is radio frequency equipment in the form of an antenna.

[0025] Advantageously, the kinematics of the device according to the present disclosure makes it possible to achieve high performance both in terms of resolution and travel.

[0026] Furthermore, according to another advantage of the invention, the symmetrical configuration of the device according to the invention and the possibility of producing a single-material device makes it possible to obtain a temperature-invariant behavior because it makes it possible to maintain a substantially unchanged reduction ratio.

[0027] Advantageously, the device according to the invention has great rigidity along the actuation axis.

[0028] In embodiments, according to yet another advantage, the lower blade of the device, which is connected to the equipment to be positioned, can also be connected to the support frame of the device by a flexible lateral blade, making it possible to take up the forces oriented in a direction perpendicular to the direction of movement and perpendicular to the direction of this blade. Such a lateral blade is useful for taking up lateral forces during launching and thus protecting the equipment. The blade also improves transverse rigidity. Brief description of the drawings

[0029] Other characteristics, details and advantages will appear on reading the detailed description below, and on analyzing the attached drawings, in which: Fig.l

[0030] [Fig.l] schematically represents, in front view, a device for adjusting the positioning of equipment according to one embodiment. Fig. 2a

[0031] [Fig.2a] schematically represents, in front view, a translation of the equipment in a first direction. Fig. 2b

[0032] [Fig.2b] schematically represents, in front view, a translation of the equipment in a second direction. Fig. 3a

[0033] [Fig.3a] schematically represents a front view of a device for adjusting the positioning of equipment according to an embodiment in which the device comprises a lateral blade connecting the lower blade to the support frame. Fig. 3b

[0034] [Fig.3b] schematically represents a side view of the embodiment of the [Fig.3a]. Fig. 4a

[0035] [Fig.4a] schematically represents an assembly comprising a wall of a equipment and several devices for adjusting the position of equipment, seen from below. Fig. 4b

[0036] [Fig.4b] schematically represents a side view of the whole of [Fig.4a]. Fig. 5a

[0037] [Fig.5a] schematically represents, in front view, a first configuration of maintenance at launch of a device for adjusting the positioning of equipment. Fig. 5b

[0038] [Fig.5b] schematically represents, in front view, a second configuration of maintenance at launch of a device for adjusting the positioning of equipment. Fig. 6

[0039] [Fig.6] shows the conventions used for the kinematic analysis of the device in front view. Description of the embodiments

[0040] Reference is now made to [Fig. 1] which schematically represents a device 1 for adjusting the position of equipment 9, in particular spatial equipment 9 such as for example a component of a telescope, for example a mirror of a telescope, a prism, or a radiofrequency antenna.

[0041] One or more adjustment devices 1 can thus be used to adjust the position of a piece of equipment 9. In the case of a single device, the position of the piece of equipment 9 can be adjusted in translation. Alternatively, with reference to FIGS. 4a and 4b, which represent an assembly comprising a piece of equipment 9 and devices 1 for adjusting the position of the team 9, respectively in a bottom view and a side view, three adjustment devices 1 can be used to adjust the position at three points of a piece of equipment 9, which makes it possible to finely adjust a translational position and an orientation of the equipment along two axes of rotation. In the case where the piece of equipment 9 is circular or has axial symmetry, the pieces of equipment are advantageously regularly distributed around this axis.

[0042] Returning to [Fig.l], the position adjustment device 1 comprises an actuator 10, fixed on a support frame 19, the actuator 10 being adapted to generate a translational movement along an axis XX, hereinafter referred to as the central axis. The actuator 10 may comprise a motor, for example a stepper motor, generating a rotational movement and a device for converting the rotational movement generated by the motor into translational movement along the axis XX. In embodiments and in accordance with the example shown in [Fig.l], the actuator 10 may comprise a geared motor 11 formed by a stepper motor and a planetary reducer, driving a screw-nut system 12. The actuator has a determined input resolution, this input resolution being for example defined by the displacement obtained along the axis XX (in the example given above, the displacement of the nut) for a step of the stepper motor. This input resolution may be several hundred nanometers, for example between 250 and 500nm.

[0043] Furthermore, the device 1 for adjusting the position of a piece of equipment 9 comprises a kinematic reduction stage 20, the arms of which are sized and arranged, as detailed below, to have an output resolution of several tens of nanometers, for example between 20 and 50 nm for the input resolution between 250 and 500 nm.

[0044] The kinematic reduction stage 20 is also fixed to the frame, and comprises on the one hand a first interface 201 for joining with the equipment, at which the kinematic reduction stage 20 is secured to the equipment 9, and on the other hand a second interface 202 for joining with the actuator 10, at which the kinematic reduction stage 20 is secured to the actuator 10. The support frame 19 is a supporting structure for the equipment and the position adjustment device 1. In the case of space equipment, this equipment may be on board a spacecraft of the satellite, probe or space station type, and the support frame may be a supporting structure, for example a wall, of the spacecraft.

[0045] The kinematic reduction stage 20 comprises a set of arms articulated between the two junction interfaces 201, 202 and the support frame 19, and whose dimensioning and relative movements are configured to allow, when the second interface moves along the axis XX, that the first junction interface 201 also moves along the axis XX, in the same direction, and according to a reduced amplitude of a determined reduction ratio.

[0046] The set of articulated arms of the kinematic reduction stage 20 comprises two arms 21 at the input of the reduction stage 20, these two arms being articulated with each other at the level of the second interface 202 of junction with the actuator 10. For example, each arm can be connected to the output of the actuator, this output being for example formed by the nut in translation, in the example mentioned above, and the connection of each arm 21 with the output of the actuator is articulated to allow the articulation between the two arms. The two arms form between them an obtuse angle, that is to say between 90° and 180°. In addition, the two arms extend transver- dirty to the central axis XX.

[0047] The set of articulated arms of the kinematic reduction stage 20 also comprises two external lateral arms 22, connected on the one hand to the frame 19 and on the other hand to the arms 21 at the input of the reduction stage. Thus, each external lateral arm 22 is connected on the one hand to the frame 19 and on the other hand to one end of one of the arms 21 at the input of the reduction stage, opposite the interface 202 for joining to the actuator. The external lateral arms 22 are thus articulated on the one hand with the frame and on the other hand with the arms 21 at the input of the reduction stage.

[0048] As shown schematically in the front views of Figures 1, 2a and 2b, the input arms of the reduction stage 21 and the external lateral arms 22 form, in a neutral configuration of the kinematic reduction stage, an M-shaped profile, the midpoint of the M of which corresponds to the interface 202 for joining to the actuator. In embodiments, the angle formed between the external lateral arm 22 and the arm 21 to which it is connected is for example between 60 and 100°. The external lateral arms 22 may be inclined relative to the central axis XX so that their ends connected to the arms 21 are closer to the central axis than their ends connected to the frame 19.

[0049] The set of arms of the kinematic reduction stage 20 also comprises two internal lateral arms 24, articulated on the one hand at the junctions between the external lateral arms 22 and the arms 21 at the input of the reduction stage, and on the other hand with an arm 23 for interface with the equipment 9, this arm 23 extending transversely to the central axis XX and forming the first junction interface 201. Each internal lateral arm 24 is therefore connected by one end to the junction between an external lateral arm 22 and an arm 21 at the input of the reduction stage, and by another end to one end of the interface arm 23, with an articulation at each connection to allow relative movement between the internal lateral bottom 24 and the other arms to which it is connected.

[0050] Each internal lateral arm 24 forms an acute angle, i.e. between 0 and 90°, with the arm 21 at the input of the reduction stage and with the external lateral arm 22 to which it is connected. In embodiments, each internal lateral arm 24 forms with the external lateral arm 22 to which it is connected an angle between 0 and 30°, and forms with the arm 21 at the input of the reduction stage to which it is connected an angle between 60 and 90°. In embodiments, the internal lateral arms 24 are inclined relative to the central axis XX, so that their end connected to the arm 23 for interface with the equipment is closer to the central axis XX than the opposite end which is connected to an external lateral arm 22 and one of the arms 21 at the input of the reduction stage.

[0051] Figures 2a and 2b show the possible position variations of the stage. reduction 20, shown in dotted lines, relative to a neutral position shown in solid lines. The direction of movement of the junction interface with the actuator is represented by the arrow. Thus, during a movement of the second junction interface with the actuator, this movement tends respectively to increase ([Fig.2a]) or reduce ([Fig.2b]) the angle between the two arms 21 at the input of the reduction stage, and therefore respectively to move the external ends of the two arms 21 apart or closer together. Consequently, the internal lateral arms 24 move apart or, respectively, closer together, which tends to move the arm 23 of interface with the equipment in the same direction of movement as the junction interface with the actuator, and according to a reduction ratio which is a function of the relative lengths of the different arms.

[0052] In embodiments, in order to simplify the kinematics of the device 1, the device 1, and in particular the kinematic reduction stage 20 are symmetrical with respect to a plane of symmetry, the central axis XX being included in this plane of symmetry. The plane of symmetry is perpendicular to the plane of [Fig.l]. In this case, the two external lateral arms 22 are of the same length, as are the two internal lateral arms 24, and the input arms 21 of the reduction stage. In this case also, the second junction interface between the arms 21 and the actuator is located in the plane of symmetry and on the axis XX, in the middle of the two arms 21 at the input of the reduction stage. Finally, the interface arm 23 forming the interface with the equipment is also symmetrical with respect to the plane of symmetry and is therefore centered on this plane and intersected in its middle by the axis XX.

[0053] Concerning the relative lengths of the different arms, in embodiments, the external lateral arms 22 have a length strictly less than that of the internal lateral arms 24. Since an internal lateral arm 24 is connected to an external lateral arm 22 at a common end, the projection, on the axis XX, of the articulations between the external lateral arms and the frame 19 is located between the projection of this common end on the axis XX and the interface arm 23. In particular, the projection on the axis XX of the articulations between the external lateral arms and the frame 19 can be located on the one hand between the second junction interface with the actuator 10 and the central portion of the interface arm 23.

[0054] Furthermore, and with reference to [Fig.6], considering the projection on the axis XX of the articulations of the external lateral arms 22 with the frame, a distance, referenced y, between this projection and the second junction interface with the actuator is preferably greater than twice the distance referenced z between this same projection and the central portion of the interface arm 23.

[0055] In embodiments, the distance separating the ends of the arms 21 at the input of the reduction stage which are connected to the external lateral arms 22 and 24 internal is strictly greater than the length of the arm 23 of interface with the equipment.

[0056] In embodiments, the arms 21, 22, 23 and 24 are formed by blades having end portions of reduced thickness, as shown diagrammatically in [Fig. 3a]. This allows the arms to be rigid, but the end portions of reduced thickness give flexibility to the blades, making it possible to form the joints between the arms and therefore to allow the relative movements between the arms which are induced by the movements of the actuator. The blades have for example a thickness of between 2.5 mm and 5 mm and their pivot-forming portions have for example a thickness of between 0.5 mm and 1 mm. The blades have for example a determined width, of between 10 mm and 25 mm for example, as shown in [Fig. 3b],

[0057] In embodiments, the internal lateral arms 24, the interface arm 23, the external lateral arms 22 and the arms 21 at the input of the reduction stage are monomaterial, that is to say that each arm is formed from a single material, for example titanium or steel. Preferably, all of the arms are formed from the same material, which allows all of the arms to have the same thermal expansion characteristics and therefore not to modify the kinematic behavior of the kinematic reduction stage as a function of temperature variations. In embodiments in which a single common material is chosen for all of the arms and in which the configuration of the device is symmetrical, the kinematic reduction stage obtained is invariant with temperature, which allows to have a constant reduction ratio despite temperature variations.

[0058] As shown in [Fig.3a] or [Fig.3b], the device 1 for adjusting the position of an item of equipment may comprise a lateral blade 25, extending perpendicularly to the interface arm 23 and perpendicularly to the central axis XX. This lateral blade may be connected by one end to the interface arm 23 with the equipment, advantageously on a central portion thereof, and by another end to the support frame 19. This lateral blade is shown schematically in [Fig.3a], which represents a front view of the device 1, and in [Fig.3b], which represents a side view along a plane parallel to the plane of symmetry, where appropriate, of the device. Such a lateral blade may be flexible or articulated on the one hand with the frame and on the other hand with the interface arm, so as not to prevent the movement of the equipment 9 at the interface arm 23.The lateral blade 25 thus makes it possible to take up forces oriented in a direction normal to the plane of symmetry, represented by the double arrow in [Fig.3a]. In particular, in the case of space equipment 9 being launched from Earth, the lateral blade makes it possible to take up forces during launch.

[0059] With reference to Figures 5a and 5b, in the case where the equipment 9 is space equipment, launched from Earth, the device 1 for adjusting the position of the equipment can also comprise holding and releasing equipment 30 which is adapted to temporarily hold, for the launch, either the interface arm 23, or the external lateral arms 22 of the reduction stage 20, and to hold the launch forces induced on this reduction stage. [Fig. 5a] schematically represents the first configuration of the holding and releasing device 30 in which the mobile part of the kinematic reduction stage, at the interface with the equipment, is held rigidly and the articulations of the external lateral arms 22 with respect to the frame are left free to allow the forces to be taken up. [Fig.5b] schematically represents the second configuration of the holding and releasing device 30 in which the interface with the equipment of the kinematic reduction stage is free and the articulations of the external lateral arms 22 with respect to the frame are rigidly held. In both cases, the kinematic reduction stage comprises articulations which are not rigidly held to allow the forces to be held during launch.

[0060] With reference to the front view of Figure 6, we note the length of each internal lateral arm 24, L the length of each arm 21 at the input of the kinematic reduction stage, / 3 the length of each external lateral arm 22 and / 5 the half-length of the interface arm 23 with the equipment.

[0061] We also note, with reference to the front view of [Fig.6], the angle formed between an internal lateral arm 24 and the axis XX of movement, ^2 the angle formed between the angle formed between an external lateral arm 24 and the axis XX of movement, and 0 the angle formed between an arm 21 at the input of the reduction stage and an axis perpendicular to the axis XX of movement.

[0062] We also note, with reference to the front view of [Fig.6], y the distance between the junction interface with the actuator and the projection, on the axis XX, of the articulation between the external lateral arm 22 with the frame; z the distance between the junction interface with the equipment and the projection, on the axis XX, of the articulation between the external lateral arm 22 with the frame; and b the distance between the articulation between the external lateral arm 22 with the frame and the axis XX of movement.

[0063] Finally, with reference to the front view of [Fig.6], we note f the maximum stroke of the junction interface with the equipment, corresponding to the extreme movements of the actuator 10. Without going into the details of the equation, we understand that we can adjust the reduction ratio by adjusting the lengths of the arms. During a movement of the interface with the actuator, the increase or respectively the decrease of 0 causes the increase or respectively the decrease of ^2 to cause a movement of the interface arm 23 in one direction or the other. In addition, the fact in particular of placing the internal lateral arms and the interface with the equipment below the M, allows travels meeting the objectives of precision and linear output travel targeted. The internal lateral arms are for example longer than the external lateral arms.

[0064] The resolution obtained can thus be less than 25 nm and is even less than 10 nm, in particular over a part of the input stroke of the actuator, and the maximum output stroke of the device can advantageously be greater than 500 pm, for example, for an input stroke between 5 mm and 20 mm. Furthermore, for a given geometric configuration, even if the reduction ratio is not constant, the reduction ratio remains known in advance and thus allows the advantageous use of the invention.

[0065] The structure according to the invention comprises in particular a pair of articulations each connecting an arm 21 for connection with the actuator, an arm 22 articulated moreover with the frame and an arm 24 for connection with the interface of the equipment, thus allowing a particular and advantageous kinematics compared to the prior art.

Claims

Claims

1. Device (1) for position adjustment adapted for spatial equipment (9), comprising: - an actuator (10) fixed on a support frame (19) adapted to generate a translational movement along a central axis (XX) and - a kinematic reduction stage (20) fixed to the frame (19) and comprising a first interface (201) for junction with the equipment, characterized in that the kinematic reduction stage (20) comprises: - two arms (21) at the input of the reduction stage articulated with each other at a second interface for junction with the actuator, the two arms (21) at the input of the reduction stage forming an obtuse angle between them,- two external lateral arms (22) articulated on the one hand with the frame (19) and on the other hand with the two arms (21) at the input of the reduction stage and - two internal lateral arms (24) articulated on the one hand at the junctions between the external lateral arms (22) and the arms (21) at the input of the reduction stage and on the other hand with an interface arm (23) arranged transversely to the central axis (XX) to form the first junction interface with the equipment, each internal lateral arm (24) forming an acute angle with one of the arms (21) at the input of the reduction stage and with one of the external lateral arms (22), the kinematic reduction stage being dimensioned so that a displacement of the second junction interface with the actuator along the central axis, in one direction and according to an amplitude causes a displacement of the interface arm (23) along the central axis,in the same direction and according to said reduced amplitude of a reduction ratio which is a function of the relative lengths of the arms belonging to the kinematic reduction stage.,

2. Device according to claim 1, in which the arms (21) at the input of the reduction stage and the external lateral arms (22) form an M-shaped profile.

3. Device according to claim 1 or 2, in which the projection, on the central axis, of the articulations of the external lateral arms (22) with the frame (19) is arranged between on the one hand the second junction interface with the actuator and on the other hand a central portion of the interface arm (23).

4. A device according to claim 3, wherein when considering the projection, on the central axis, of the articulations of the external lateral arms (22) with the frame (19), a distance (y) taken between this projection and the second junction interface with the actuator is greater than twice a distance (z) taken between this projection and the central portion of the interface arm (23).

5. Device according to one of the preceding claims, in which the arms, belonging to the kinematic reduction stage, which end in articulations, are each constituted by a blade of which portions at its two ends have a reduced thickness.

6. Device according to one of the preceding claims, in which the kinematic reduction stage has a plane of symmetry, the central axis (XX) being arranged in this plane of symmetry.

7. Device according to one of the preceding claims, in which the internal lateral arms (24) are inclined relative to the central axis, so that their end connected to the interface arm (23) is closer to the central axis (XX) than their end connected to the junction between one of the external lateral arms (22) and one of the arms (21) at the input of the reduction stage.

8. Device according to one of the preceding claims, in which the length of the external lateral arms (22) is strictly less than the length of the internal lateral arms (24).

9. Device according to one of the preceding claims, in which the interface arm (23) is further connected to the frame (19) by a flexible blade (25) extending perpendicular to the interface arm (23) and perpendicular to the central axis.

10. Device according to one of the preceding claims, in which the internal lateral arms (24), the interface arm (23), the external lateral arms (22) and the arms (21) at the input of the reduction stage are made of a single material.

11. Device according to one of the preceding claims, for adjusting the position of a space equipment (9), in which the device further comprises holding and releasing equipment adapted to temporarily hold the interface arm (23) or the external lateral arms (22).

12. Assembly, comprising at least one optical or radiofrequency spatial equipment (9) and at least three devices (1) according to one of the preceding claims, for adjusting the position, at at least three points, of each spatial equipment.

13. An assembly according to claim 12, wherein the spatial equipment is optical equipment in the form of a prism or a mirror.

14. An assembly of claim 12, wherein the space equipment is radio frequency equipment in the form of an antenna.

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