SUITABLE CARRIER DEVICE FOR SATELLITE DEVICES

Description

Field of invention

[0001] The present invention relates to a telescopic structure for a satellite, in the form of a carrier device for equipment of a satellite deployable by means of an inflatable tube, in particular for producing a mast such as a satellite antenna mast which is mounted folded during the launch of the rocket carrying the satellite and which will be deployed once the satellite is in position. The present invention also relates to the production of segments provided with means for snapping and retaining the segments of the carrier device. Technological background

[0002] To deploy organs on a satellite, we know inflatable masts and in particular inflatable masts that can be solidified by polymerization of reinforcement devices or solidification of the envelope of the inflatable tube making the mast.

[0003] However, these devices require a gas generator suitable for maintaining the pressure in the mast at least for the duration of the polymerization of the frame or tube.

[0004] These devices also require the design of inflatable tubes that are resistant to the space environment and to do this they use complex multi-layers combining high watertightness, great lightness and high resistance to UV rays in particular.

[0005] Document GB-A-2 072 295 discloses a carrier device for equipment of a satellite of the state of the art. Brief description of the invention

[0006] On the one hand, the present invention aims to reduce the capacity of the gas generator and simplify the production of the inflatable tube by producing a telescopic mast in the form of nested segments in which there is a simple inflatable tube which must be kept inflated only for the duration of the mast deployment.

[0007] On the other hand, the present invention aims to propose a mast which is easy to assemble and disassemble to facilitate unit tests before launch and to provide mutual locking means and means for retaining the segments adapted accordingly.

[0008] The invention relates to a device according to claim 1.

[0009] In one embodiment, the inflatable tube comprises a gas generator, said gas generator disposed within the nested nested segments.

[0010] In one embodiment, the carrier device comprises a base supporting the outermost segment and the gas generator.

[0011] In one embodiment, the device comprises a cover supporting equipment and the lower face of which constitutes a support face during deployment of the inflatable tube.

[0012] In one embodiment, the carrier device includes retractable rod locks adapted to lock the nested segments together in the stowed mast position.

[0013] In one embodiment, the attachment means are ears or collars.

[0014] In one embodiment, the segments in the folded mast position, the collar or ears of a segment of rank n rest on the edge of the segment of rank n-1 which surrounds it, or external adjacent segment.

[0015] In one embodiment, the ears include antenna cable passage holes extending with the mast.

[0016] In one embodiment, the segments are provided with mutual snap-fastening means in the unfolded position and with ribs opposing rotation of the segments relative to each other.

[0017] The invention also relates to an assembly comprising a carrier device according to the invention and an antenna.

[0018] In one embodiment, the antenna consists of a metallization formed of metal layers arranged on the nested cylindrical segments so as to form a helical pattern when the mast is unfolded.

[0019] In one embodiment, the metal layers of one segment are electrically connected to the metal layers of the adjacent segment(s) by means of connecting tabs disposed in slots of said segments.

[0020] In one embodiment, the metal layers are copper, or nickel, or gold.

[0021] In one embodiment, the antenna comprises antenna cables arranged on the mast in a helically arranged manner.

[0022] The invention also relates to a carrier device according to claim 10.

[0023] In one embodiment, the locking system comprises on the one hand the pin and the upper stop and on the other hand a spring tab carried by an external segment whose free end snaps onto a lower edge of an internal mast segment in the unfolded position.

[0024] In one embodiment, the spring tab is received in a guide groove.

[0025] In one embodiment, the segments are removable by means of an annular tool of the diameter of an inner segment slid into an outer segment and pushing back the tab to allow passage and extraction of an inner segment.

[0026] In one embodiment, the segments are provided with indexing means opposing rotation of the segments relative to each other. Brief description of the drawings

[0027] Other characteristics and advantages of the invention will be apparent from reading the following description of a non-limiting example of embodiment of the invention with reference to the drawings which represent: In figure 1 : a perspective view of a structure according to the invention deployed; Figures 2A to 2C : schematic views of the elements of the structure of the figure 1 folded and details of these elements; In Figure 3A : sectional views of structure retaining devices in the folded position; In Figure 3B : a schematic sectional view of the folded structure at the level of the devices of the figure 2 ; To Figures 4A to 4C : detailed views of means for retaining rotation and locking the segments; Figures 5A and 5B : detailed perspective section views of alternative means of rotational retention and segment guidance; Figures 6A to 6C : detailed views of segment locking means; To Figures 7 A to 7C: perspective views and transparency of the means of Figures 5A to 6C ; To Figures 8A to 8F : the representation of the arrangement of strands of an antenna according to the deployment of the mast; In figure 9 : the representation of the angular positioning of the mast segments for winding the antenna strands. Figures 10A and 10B : an embodiment of the mast, respectively in the folded and deployed positions, in which an antenna is arranged in a helical manner on the segments of the mast in the form of a metallization; Figures 11A to 11G : vertical sectional views illustrating the electrical connection by means of a tab between two metal layers of adjacent segments of the mast, in the embodiment of the Figures 10A and 10B . Detailed description of embodiments of the invention

[0028] The invention relates to a telescopic structure deployable by means of an inflatable tube.

[0029] The telescopic structure 1 as shown deployed in figure 1is made from nested segments 2, here 6 segments 2a to 2f which can be made from various materials such as a composite based on fiberglass or a thermoplastic (for example PEEK) loaded with glass or not in the case where they carry an antenna in particular or possibly metallic or carbon materials for other applications.

[0030] According to the example, the segments 2 of the mast carry turns 5 of an antenna which will deploy with the mast. The mast can also carry one or more sensors to be placed at a distance from the satellite or even carry solar panels.

[0031] As shown in the schematic view of the Figure 2A , the cylindrical segments 2a to 2f fit into each other to allow the structure to be folded and unfolded.

[0032] The segments 2 are annular segments nested within each other when the mast is folded. They have an upper part provided with a rim or legs 4 as shown in Figure 2B which carry antenna strands or connecting wires or cables to a device carried by the mast.

[0033] The mast is deployable under the action of an inflatable tube 3 of size shown schematically in Figure 2C which fits inside the segments.

[0034] The segments of the invention are constructed in such a way that the pressure in the inflatable tube 3 arranged inside the smallest segment does not have to be maintained after deployment of the mast, the latter retaining its deployed shape without maintaining pressure in the tube.

[0035] To do this, the segments 2a to 2f from smallest to largest are locked to each other in the deployed position by locking means which will be described below, which reduces the quantity of gas that must be generated by a gas generator initiated for the deployment of the mast and inflating the inflatable tube. This makes it possible to reduce the volume and mass of the generator and the tube, the generator being able in particular in this application to be a simple and inexpensive generator.

[0036] Back to the Figure 2A , in the folded position, the segments are nested with the rim or legs of a more inner segment above or in contact with the edge of a more outer segment.

[0037] The mast has a cover 6 attached to the innermost segment 2a which will become the distal segment of the mast. On this cover can be attached the end of the antenna, a sensor or any other equipment intended to be used remotely from the satellite.

[0038] Back to the figure 1 , legs 4 or edge 41, 41' of the figure 8 for example are provided with notches or holes 4a for passing through the strands 5 of the antenna or for guiding one or more electrical cables supplying one or more sensors or other equipment at the end of the mast.

[0039] In Figure 3A a device 7 for temporarily locking the segments in the folded position is shown, called "pinpullers" in English for a retractable rod lock. This device comprises an actuator and a retractable rod 7a shown deployed in the top view and retracted in the bottom view.

[0040] According to the Figure 3B, two of said locks 7 are arranged back to back or one above the other head to tail inside the internal segment. The rods 7a of the retractable rod locks pass through the segments which are provided with holes adapted so as to lock these segments in the folded position during the flight of the rocket carrying the satellite until the moment of deployment of the mast.

[0041] Once the satellite is correctly positioned, the rods 7a are retracted and then the inflatable tube 3 is inflated by means of its gas generator 8 which deploys the mast.

[0042] According to the Figures 4A to 4C , the segments are provided with mutual snap-fastening means, mast in deployed position.

[0043] It is necessary to prevent the segments from rotating relative to each other and for this purpose means of indexing the segments are provided.

[0044] According to the Figure 4A and on the enlargement of the Figure 4B, the interior of an external segment 21 comprises ribs 10 along generatrices of the segment and a housing 11 while an internal segment 22 comprises a spring tab 12 provided with a lug 12a as shown in Figure 4C . The lug 12a is sized to be retained laterally between the ribs 10 during deployment of the mast and sliding of the inner segment out of the outer segment until it is positioned under the action of the spring tab in the housing 11 to lock the segments in the deployed position. According to the example shown, the lug 12a is arranged on the outer face of the inner segment and the ribs and the housing on the inner face of the outer segment. In the embodiment of the Figure 4A , the indexing means are formed of ribs 10, housing 11 and spring tab 12 including lug 12a.

[0045] THE Figures 5A to 7Crepresent an improved device providing a lower stop between the segments in the folded position, an upper stop in the unfolded position as well as locking the segments together and also allowing easy assembly and disassembly of the segments for pre-launch testing.

[0046] To do this, the device firstly comprises a pin / cam path combination with, as shown in the Figure 5A : on the internal face of a segment 21' a bayonet-type entry groove 17 opening into an elongated groove 18 which does not open onto the upper face of the segment or the lower face but which defines two extreme stopping points 18a, 18b and, on the external face of a segment 22', a pin 19 as shown in Figure 5B adapted to slide into the entry groove and then into the elongated groove.

[0047] The movement of the pin in the groove 18 between the stopping points is shown diagrammatically in Figures 6A to 6C . The position of the Figure 6A is a folded mast position where the segments are nested and the pin 19 is in abutment on a low stopping point 18b. The position of the Figure 6B is an intermediate position for which pin 19 is halfway between the stops. The position of the Figure 6C is a deployed mast position where the segments are extended with pin 19 abutting against the upper stop 18a.

[0048] The grooved pin device further forms the indexing means between the segments and the elongated groove 18 locks the segments in rotation relative to each other.

[0049] This configuration, which can be reversed between the internal and external segments, makes it possible to assemble and disassemble the segments by pushing the internal segment into the external segment and then rotating it so that the pins enter the groove 17, slide to the bottom of this groove and then join the groove 18 and can also slide there. To disassemble the mast and therefore to remove the internal segment from the external segment, the opposite is done by rotating and extracting the pins through the entry groove 17.

[0050] For locking the segments in the deployed position, the device comprises spring tabs 13 facing inwards on an external segment 21' according to the example of the Figure 7A . When the segments are in the folded mast position, these tabs 13 are stressed against the external wall of the internal segment 22' as shown in Figure 6A. During deployment the tabs are received in guide grooves 16 of the internal segment 22' as shown in Figure 6B . When the mast is in the deployed position as shown in Figures 6C , these tabs are released and their free end snaps against the lower edge 22'a of the internal segment.

[0051] The grooves / tongues 13, 16 participate in the indexing of the segments when the tongues slide in these grooves.

[0052] Thus the pins 19 and the grooves 18 retain the internal segments in the high position and in the low position in the external segments and the spring tabs 13 lock the mast segments in the deployed position.

[0053] To limit the deployment efforts of the mast, the guide groove 16 as shown in particular in Figure 6A and 6Cand receiving the spring tab 13 has a ramp-shaped end portion 16a against which the spring tab 13 slides before locking the segments.

[0054] It should be noted that to assemble the segments according to the Figure 7C it is necessary to push the spring tabs 13 outwards, for example using a ring tool.

[0055] To disassemble the segments, the tab 13 is capable of being retracted by inserting the annular tool into an external segment to allow the tabs 13 to retract and thus allow the internal segment to slide out of the external segment.

[0056] As regards the case of a mast carrying an antenna, as seen above, the antenna strands are arranged between the segments according to a configuration shown in Figures 8A to 8F .

[0057] In this example, the segments are provided with collars 41, 41' instead of ears, but an embodiment in which the collars are replaced by pierced ears distributed around the upper edge of the segments is possible. The strands pass through the collars in the same way as the ears through holes made in them.

[0058] There Figure 8A represents two segments 2p, 2q pushed into each other, mast in folded position.

[0059] The visible antenna strands 51, 52 passing through the collars 41, 41' are folded in the shape of a half-loop. The progressive deployment of the mast is shown in Figures 8B to 8E . The half-loops gradually unfold as the inner segment 2q exits the outer segment 2p to the position of the Figure 8F for which the antenna strands are taut and the segments in the deployed mast position.

[0060] It should be noted that the passages of the strands are angularly offset to give a helical shape to the strands around the segments, particularly in the case of an RF antenna.

[0061] THE Figures 8C to 8F allow two whole strands 51, 52 to be seen, the upper part of a third strand 53 and the lower part of a fourth strand 54 when they are tensioned.

[0062] There figure 9schematizes for a mast with six sections 2a to 2f two variants of folding of two strands 501 and 501'. Strand 501 has half-loops all oriented on the same side which gives small bending radii to the strand at the crossings between segments while strand 501' has an alternation of right and left half-loops so that the bending of the strand at the crossings between the segments is not bent. The second variant for which the antenna strands 501' are folded in alternating right and left half-loops reduces the bending of the strands at the holes 4a for the passage of the strands between the segments to reduce the deformations of the strands at the points of passage of the strands between the segments and gives a better distribution of the half-loops between the strands.

[0063] As seen previously, when the mast carries an antenna, the segments carry strands 51, 52, 53, 54 of the antenna passing through the segments through holes 4a in the ears 4 or the collars 41 of the segments.

[0064] The segments as shown are angularly offset from each other to give a helical shape to the antenna strands.

[0065] The angular offset of the successive segments accumulates to obtain a total angle Θ between 360° and 400° depending on the desired RF performance.

[0066] The table below gives an example of realization with the angle of rotation for each segment of a six-segment mast. Section 1 Section 2 Section 3 Section 4 Section 5 Section 6 Rotation of the strand in degrees 60,6 54,1 60,6 67,1 73,6 81,4

[0067] In an alternative embodiment illustrated in the Figures 10A-10B And 11A-11G, the antenna arranged on the mast consists of a metallization formed of metallic layers 60 arranged on the nested cylindrical segments of said mast so as to form a helical pattern when the mast is unfolded (see Figure 10B ).

[0068] The metal used can be, for example, copper, nickel or gold.

[0069] In reference to the Figures 11A-11G , the metal layers 60 of a segment are electrically connected to the metal layers of the adjacent segment(s) by means of connecting tabs 61, for example made of copper, arranged in slots 62 of the segments 2 of the mast. “Adjacent segments” means segments immediately adjacent when the mast is in the folded position. For a given segment, the adjacent segment(s) therefore correspond(s) to the segment(s) of the mast with the immediately smaller and / or larger diameter.

[0070] The slots are arranged in the upper parts of the segments, so that an electrical connection can be provided when the mast is deployed.

[0071] THE Figures 11A to 11D illustrate the installation of the connecting tab 61 before assembling the mast segments together. With reference to the Figures 11A and 11B , the connecting tab 61 is introduced by an external surface of a mast segment into the slot 62 arranged in the upper part of said segment, in the direction of the arrow. The tab has a first fold 610 so as to have a substantially right angle so that a first part, or first arm 61a of the connecting tab comes into contact with the electrical layer 60 of the segment, while the other part passes through the slot 62 and opens onto an internal surface of said segment. The tab part opening onto the internal surface of the segment is folded ( Figure 11C) in the opposite direction to the first fold. The tab thus has a second fold 611, as illustrated in the Figure 11D , to form an intermediate arm or second arm 61b, disposed between the first fold 610 and the second fold 611, and a third arm 61c.

[0072] THE Figures 11E to 11G illustrate the establishment of electrical contact between the electrical layers of two adjacent segments, an "external" segment and an "internal" segment, during deployment of the mast. By "external" and "internal" we mean that an average diameter of the external segment is greater than that of the adjacent internal segment. A tab has been placed in a slot of the external segment according to the method seen above with reference to Figures 11A-11D; the third arm 61c is in contact with a non-metallized portion of the inner segment. Upon deployment, the inner segment moves upward relative to the outer segment, as shown in the figures. When the mast is deployed, the connecting tab is in contact with a metal layer disposed on a lower portion of the inner segment, thereby providing an electrical connection between the metal layers of the inner and outer segments.

[0073] The invention defined by the claims is not limited to the examples shown and in particular the number of segments may be different from the number of segments shown.

Claims

1. Carrier device for satellite equipment, in the form of a telescopic mast, said device comprising a set of nesting cylindrical segments (2, 2a, 21, 22), fitted in one another when the mast is retracted, an inflatable tube (3) under the action which the mast is deployable, the segments being provided with means (4, 6) for attaching equipment carried by the mast, said device being characterised in that the inflatable tube (3) is disposed inside the smallest segment.

2. Carrier device according to claim 1, wherein the inflatable tube comprises a gas generator (8), said gas generator disposed inside fitted-together nesting segments.

3. Carrier device according to claim 2, comprising a base (100) supporting the outermost segment (2) and the gas generator (8).

4. Carrier device according to claim 1, 2 or 3, comprising a cover (6) supporting equipment and the bottom face of which constitutes a support face when the inflatable tube (3) is deployed.

5. Carrier device according to any one of the preceding claims, comprising bolts (7) with a retractable rod (7) adapted to lock together the fitted-together segments in the retracted-mast position.

6. Carrier device according to any one of the preceding claims, wherein the attachment means are lugs (4) or collars.

7. Carrier device according to claim 6, wherein, with the segments in the retracted-mast position, the collar or lugs of a segment of rank n rest on the edge of the segments of rank n-1 that surrounds it.

8. Carrier device according to claim 6 or 7, wherein the lugs comprise passage holes for antenna cables (5) deploying with the mast.

9. Carrier device according to any one of the preceding claims, wherein the segments are provided with mutual snapping-in means (11, 12) with the mast in the extended position and with ribs (10) opposing a rotation of the segments with respect to one another.

10. Carrier device according to any one of claims 1 to 4 and 6 to 8, wherein the segments comprise a system for locking the segments together in the extended position (18a, 19, 13, 22a) and holding means in the form of an upper stop (18a) between the segments in the extended position and a lower stop (18b) between the segments in the retracted position, said stop means forming part of a pin (19) and cam-track (18) system provided with an entry groove (17) of the bayonet type and an elongate groove (18) the ends of which form said stop means (18a, 18) for the pin (19).

11. Carrier device according to claim 10, wherein the locking system comprises on the one hand the pin (19) and the upper stop (18a) and on the other hand a spring tongue (13) carried by an external segment (21) the free end of which snaps onto a bottom edge (22a) of an internal segment (22) with the mast in the unfolded position.

12. Carrier device according to claim 11, wherein the spring tongue is received in a guide groove (16).

13. Carrier device according to claim 11 or 12, wherein the segments are demountable by means of an annular tool with the diameter of an internal segment slipped into an external segment and pushing the tongue to enable an internal segment to pass and be extracted.

14. Carrier device according to any one of claims 10 to 13, wherein the segments are provided with locating means (18, 19) opposing a rotation of the segments with respect to one another.

15. Assembly comprising a carrier device according to any one of the preceding claims and an antenna.

16. Assembly according to claim 15, wherein the antenna consists of a metallisation formed by metal layers (60) disposed on the nesting cylindrical segments so as to form a helical pattern when the mast is extended.

17. Assembly according to claim 16, wherein the metal layers (60) of a segment are electrically connected to the metal layers of the adjacent segment or segments by means of connection tongues (61) disposed in slots (62) of said segments.

18. Assembly according to claim 16, wherein the metal layers are made from copper or nickel or gold.

19. Assembly according to claim 15, wherein the antenna comprises antenna cables (5) disposed on the mast helically.