Outrigger construction

Sept. 20, 1971

3,606,211

W. ROERSCH ETAL

OUTRIGGER CONSTRUCTION

Filed June 30, 1969

Sheets-Sheet 1

6.

<img file="US3606211A_D0001.tif" />

\ki IX INVENTORS

Wolfgang Roersch

By Gunther La Roche

ATTORNEYS

3,606,211

W. ROERSCH ETAL

OUTRIGGER CONSTRUCTION

Sept. 20, 1971

Filed June 30, 1969

Sheets-Sheet 2

<img file="US3606211A_D0002.tif" />

INVENTORS

Wolfgang Roersch

GOnther La Roche

By

ATTORNEYS

Sept. 20, 1971 w. roersch etal 3,606,211

OUTRIGGER CONSTRUCTION

Filed June 30, 1969 4 Sheets-Sheet 3

<img file="US3606211A_D0003.tif" />

<img file="US3606211A_D0004.tif" />

INVENTORS

Wolfgang Roersch Gunther La Roche

By

ATTORNEYS

Sept 20, 1971 w.roersch etal 3,606,211

OUTRIGGER CONSTRUCTION

<img file="US3606211A_D0005.tif" />

<img file="US3606211A_D0006.tif" />

INVENTORS

Wolfgang Roersch

Gunther La Roche

ATTORNEYS

3,606,211

Patented Sept. 20, 1971

United States Patent Office

3,606,211 OUTRIGGER CONSTRUCTION Wolfgang Roersch and Gunther La Roche, Munich, Germany, assignors to Messerschmitt Bolkow Gesellschaft mit beschrankter Haftung, Munich, Germany Filed June 30,1969, Ser. No. 837,713 Claims priority, application Germany, Oct. 8,1968, P 18 01 777.1 Int. Cl. B64g 1 /00

U.S. Cl. 244—1SS 26 Claims

ABSTRACT OF THE DISCLOSURE

An outrigger secured to a space vehicle is displaceable between an inoperative position mounted in a compact arrangement against the vehicle and an operative position in which it is extended outwardly from the vehicle. The outrigger is formed of a main outrigger section which extends outwardly from the vehicle in the operative position and auxiliary outrigger sections which extend laterally from the main outrigger section in the operative position. In the inoperative position the auxiliary outrigger sections are disposed in a folded arrangement on the main outrigger section.

The present invention is directed to an outrigger construction secured to the outer surface of a space vehicle and is useful, for example, in mounting solar cells or for acting as an antenna, and, more particularly, it is directed to an outrigger formed of a main section and auxiliary sections which can be disposed in a compact arrangement against the outer surface of the space vehicle and then opened up or unfolded into an operative position extending outwardly from the vehicle.

When solar cells are used on vehicles as a source of energy a great number of the cells are required, and as a result, it is necessary for the outriggers supporting these cells to have as large a surface area as possible. However, it is also important that such outriggers occupy as small a space as possible when the space vehicle is passing through the earth’s atmosphere. Moreover, the weight of the outriggers should be as low as possible. When the outriggers are being used they must be stable enough to align the solar cells in a plane facing toward the sun and to maintain this position while the cells are being used.

Known outriggers for supporting solar cells have been formed of a number of rigid parts hinged together in a folded arrangement against the vehicle and when they are ready for use the rigid parts can be extended and assembled in the form of a rigid wing-like structure extending outwardly from the vehicle. This type of outrigger has the disadvantage that its width is limited by the maximum length of the space vehicle and, as a result, affords a relatively small surface when extended for use.

Another outrigger which has been used, is formed at at least a pair of flexible, longitudinal extending girders which are wound about the space vessel. Extending between the flexible girders are mat-like devices on which the solar cells are mounted. The girders are formed of tubes which can be inflated in the operating position and stiffened with plastic foam. Flexible lines are provided within the tubes forming the girders for conducting pressurized gas to the outer ends of the tubes. When the outrigger is wound about the vehicle the ends of the tubes are located on the outside. Similarly, this outrigger is limited in its width by the maximum length of the space vehicle and it cannot form large-surface outriggers for solar cells.

Another outrigger which has been used on space vehicles consists of a wire or strip of a nickel-titanium al30 loy having about equal portions of nickel and titanium. The wire cools off slowly after heating through a certain temperature range of the transposition and stretching into the extended state. The wire is wound below a certain temperature and can resume its original form after it has been heated through the temperature range required for arrangement in the extended state. However, this outrigger construction is much too heavy to provide a large surfaced outrigger for supporting solar cells on a space vehicle.

It is the primary object of the present invention to provide an outrigger which is easily and safely openable from a compact arrangement on the surface of a space vehicle into a large-surfaced outrigger extending outwardly from the vehicle. Moreover, the outrigger construction is highly stable in its opened or operative state.

Another object of the invention is to provide an outrigger construction which can be disposed in varied folded, wrapped or wound arrangements on the exterior surface of the space vehicle.

Still another object of the invention is to provide an outrigger construction formed of a main outrigger section made up of rigid parts and auxiliary outrigger sections extending laterally from the main outrigger section and formed of flexible members which can be stiffened to form a stable support structure.

Moreover, another object of the invention is to afford a simple arrangement for opening the outrigger construction from its inoperative to its operative position.

Therefore, in accordance with the present invention, the outrigger construction is formed of a main outrigger section comprised of a number of rigid parts articulated to one another so that they can be arranged in a compact arrangement on the surface of the space vehicle and auxiliary outrigger sections foldable with the main outrigger sections and extendable laterally from the main outrigger section to form a greatly increased surface for supporting solar cells or the like.

In one embodiment of the present invention, the main outrigger section is formed of a number of parts of equal length with an auxiliary outrigger section being secured to each side of the parts for extending laterally outwardly from the main outrigger section. A pair of spaced tubular members are secured to brackets mounted along the edge of each of the parts and extend laterally outwardly from the rigid parts on the opposite sides of the main outrigger section for supporting individual auxiliary outrigger sections. The width of the individual auxiliary outrigger sections corresponds approximately to the length of the parts of the main outrigger section and their length is approximately an integral multiple of the width of the parts of the main outrigger section. On the opposite surfaces of the parts forming the main outrigger section web members extend around three edges and form a three sided box each with an opening along an opposite edge of the part. In the inoperative position of the outrigger the auxiliary outrigger sections are folded into the boxes on the opposite surfaces of the parts and the open sides of the boxes face in the direction in which the auxiliary outrigger sections are extended from the inoperative position to the operative position.

The main outrigger section is formed of a number of parts made of light metal or plastic which are articulated together by means of hinges. In the inoperative position the parts of the main outrigger section can be folded in a compact arrangement and then can be opened into the operative position to form a rigid surface. The auxiliary outrigger sections consist of tubular members which extend laterally from the main outrigger section with a sheet of a flexible material, such as polyamide or similar material, extending between the tubular members to provide the auxiliary outrigger surface. The tubular mem3.606.211 bers are provided with a glass fiber-gelatin lamination and initially they are made flexible by steeping in water or glycol. However, when disposed in the operative position the tubular members are automatically stiffened by evaporation of the steeping agent.

Positioned within the flexible tubular members are small diameter, thin wall tubes formed of polyamide which give the tubular members their generally circular form by passing a pressurized gas through the tubes. Moreover, the pressurized gas within the tubes in the tubular members aids in the unfolding or opening of the auxiliary outrigger sections from the inoperative to the operative position. The tubular members which act to stabilize the auxiliary outrigger sections are covered with a polyamide sheet which prevents the freezing of the water which gives the tubular member its flexibility. However, the sheet does not prevent the evaporation of the water.

In another embodiment of the invention the parts forming the main outrigger section are articulated together by equilaterally arranged hinges, and one or several of said main outrigger sections are wound side by side or in superimposed relationship in one or a number of polygonal sources about the surface of the space vehicle. When being opened from the inoperative to the operative position. the parts of the main outrigger section can be displaced by means of a lifting cable, prestressed springs or by centrifugal forces.

In another preferred embodiment of the present invention, the parts forming the main outrigger section are of equal length and a stabilizing tubular member is secured to each of the opposite edges of each part adjacent one end thereof. The length of the tube members corresponds approximately to an integral multiple of the width of the parts of the main outrigger section. The auxiliary outrigger sections are formed by placing a sheet of polyamide across the tubular members so that a continuous auxiliary outrigger section is provided. In the inoperative position the oppositely extending auxiliary outrigger sections are folded into one another in an interleaved arrangement on the parts of the main outrigger section. In this folded construction the portions of the auxiliary outrigger sections secured to the sides of the main outrigger section are located outwardly or on the top of the folded over arrangement. In the inoperative position the auxiliary outrigger sections are folded on the main outrigger section which is wound about the space vehicle and fits in a correspondingly dimensioned recess in the vehicle so that the auxiliary outrigger sections lie between the parts forming the main outrigger section and the surface of the space vehicle. In this arrangement the auxiliary outrigger sections are secured against displacement and against any friction damage caused by acceleration of the space vehicle. The parts forming the main outrigger section are locked together by spring locks and can be opened by an explosive charge or by an unlocking mechanism.

In another embodiment of the invention, the main outrigger section is formed of a plurality of parts of unequal length and has an auxiliary outrigger section extending laterally from each of its sides. The parts of the main outrigger section are connected to each other by side bars or hinges and can be positioned relative to one another at angles of 90 and 180 degrees respectively. The stabilizing tubular members of the auxiliary outrigger section are divided into two types, the first type extend along the inner and outer edges of the auxiliary outrigger section and have a uniform circular cross-section, the second type of tubular members are located intermediate the edges and extend laterally outwardly from the main outrigger section. The second type of tubular members are provided with reinforcing adjacent the main outrigger section and are folded in flat double layer strips in the inoperative position. Due to their reinforcing, the second type of tubular members have a conical appearance and, as a result, have a non-uniform cross-section. In the folded inoperative position on the main outrigger section the auxiliary outrigger section has the reinforced sections of the second type of tubular members adjacent the parts 5 forming the main outrigger section. Further, in the inoperative position the main outrigger section and its auxiliary outrigger sections are wound in a manner similar to a rolling shutter providing a compact arrangement against the surface of the space vehicle. The outer sur10 faces of the main outrigger section in the inoperative position are provided with a lifting cable for displacing the outrigger from its inoperative to its operative position. One or more of these outriggers can be wound about the space vehicle and nothing is changed in the manner in 15 which the auxiliary outrigger sections are folded on the main outrigger section.

In the embodiments of the present invention, where the auxiliary outrigger sections are folded so that the portions of the auxiliary outrigger section disposed ad20 jacent the main outrigger section in the operative position are located adjacent the parts forming the main outrigger section, thin tubes of polyamide are inserted into the stabilizing tubular members and these tubes conduct pressurized gas which serves to unfold the auxiliary outrigger 2S sections into the operative positions. In the various embodiments of the invention, the entire surface of the outrigger or certain parts may be covered and protected by a thin foam rubber mat when in the inoperative position. This protective covering prevents displacement and 30 frictional damage which may occur due to the operation of the space vehicle. Since the rubber mat is not connected to the outrigger but is placed between adjacent surfaces in the folded inoperative position it can drop off the outrigger when it is opened into its operative posi35 tion.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification, For a better understanding of the invention, its 40 operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described preferred embodiments of the invention.

In the drawings:

FIG. 1 is a view of one embodiment of the present ⁶ invention illustrating a pair of outriggers secured to a space vehicle;

FIG. 2 is a partial view, similar to FIG. 1, with one of the outriggers extended into its operating position;

₅₀ FIG. 3 is a cross-sectional view through a portion of the outrigger shown in FIG. 1 with the outrigger in its inoperative position;

FIG. 4 is an enlarged cross-sectional view of a stablizing tube member shown in FIG. 2;

FIG. 5 is a cross-sectional view of the stabilizing tube member displayed in FIG. 4, shown expanded into a circular form;

FIG. 6 is a top view of an octagonal space vehicle having the outriggers as shown in FIG. 1 wrapped around θθ the vehicle;

FIG. 7 is a perspective view of another embodiment of the present invention, illustrating a hexagonal space vehicle to which two outriggers are secured with one outrigger in the extended operating position and the other outrig_6g ger in a position intermediate the inoperative and operative position;

FIG. 8 is a transverse view through a part of the outrigger illustrated in FIG. 7 with the outrigger in its folded inoperative position;

γθ FIG. 9 is a plan view of another embodiment of the present invention illustrating an outrigger in its extended operating position;

FIG. 10 is a transverse view of a position of the outrigger illustrated in FIG. 9 with the outrigger disposed in its folded inoperative position; and

3,606,211

FIG. 11 is a partial top view of a polygonal space vessel having an outrigger secured to it and arranged in its operative position.

In FIG. 1, a rectangularly shaped space vehicle 1 is shown having an outrigger 2 secured to each of a pair of its opposite sides. In FIG. 1 the outrigger 2 is arranged in the inoperative folded or collapsed position while in FIG. 2 the outrigger is shown in its opened or operative position. Each of the outriggers 2 is formed of a main outrigger section comprised of the parts 3 and a pair of auxiliary outrigger sections 6 extending laterally from the parts 3 and disposed in the same plane with the main outrigger section.

As shown in the operative position in FIG. 2, the main outrigger section is comprised of equal length rigid parts 3 made of a light metal or plastic which are connected by means of hinges 4 and prestressed springs 5 in a serial arrangement extending outwardly from vessel 1. When the outrigger is opened to the operative position the hinges are automatically locked so that the main outrigger section provides a rigid, outwardly extending member.

As indicated in FIG. 2, an auxiliary outrigger section 6 extends from each side of the main outrigger section. In the inoperative position, one auxiliary outrigger section is mounted or positioned on each face of the parts 3 of the main outrigger section. In the extended operative position, as illustrated in FIG. 2, the auxiliary outrigger sections are made up of separate subsections each consisting of a pair of stabilizing tubular members 7 formed of glass fiber-gelatin-laminates. Initially, before the tubular members 7 are folded into the inoperative position of the outrigger they are steeped in water or glycol which makes them flexible so that they may be folded or collapsed as desired. When the outrigger is opened up into its operative position in outer space, the evaporation of the steeping agent from the tubular members causes them to stiffen and provide a rigid support for the auxiliary outrigger sections. Extending between each pair of tubular members 7 which proceed outwardly from the sides of the parts 3 is a flexible sheet of polyamide or a similar material which provides the surface of the auxiliary outrigger sections 6.

At spaced positions from and in parallel relationship with the edges of the parts 3, inflatable tubes 10 made of polyamide act as spacers for the tubular members 7 and afford additional support for the auxiliary outrigger sections as the tubular members stiffen in the operating position.

The inner ends of the tubular members 7 are reinforced and are clamped tightly in mounting brackets 8 located at the opposite corners of the side edges of the parts 3. In the operating position a plurality of rectangular surfaces 9 are provided by the polyamide sheets and these surfaces provide support for solar cells and electrical wiring, not shown.

The diameter, wall thickness, length, number and spacing of the stabilizing tubular member 7 and the intermediate support tubes 10 depend on the size of the auxilary outrigger sections and on the load which they support. It will be noted that the interval or spacing between the stabilizing tubular members which define the sides of the individual subsections of the auxiliary outrigger sections 6 are approximately equal to the length of the parts 3 which make up the main outrigger section.

In FIG. 3, the manner in which the auxiliary outrigger sections are folded on the opposite surfaces of the parts 3 of the main outrigger section is illustrated. On each of the opposite surfaces of the parts 3, the upper surface and the lower surface as shown in FIG. 3, web surfaces 12 extend in an upright manner from three of the edges of the part 3 providing an upwardly and a downwardly extending box 13 with the upper box opened on the left hand side and the lower box opened on the right hand side of the part 3.

It can be noted in FIG. 3 that a thin foam rubber mat 14 is indicated in dot-dash lines between a pair of opposed surfaces of the auxiliary outrigger section. Before the outrigger is arranged in its folded inoperative position, as indicated in FIG. 3, the rubber mat 14 is provided as a protective covering for the folded surfaces. The mat 14 prevents displacement and protects against any pressure or frictional damages which might occur during acceleration of the space vehicle. In outer space, when the outrigger is opened up into the operative position, the rubber mat, since it is not secured to the outrigger, will drop off.

As displayed in FIG. 3, the auxiliary outrigger sections are folded up so that the outer portion of the auxiliary outrigger section, that is the part most remote from the rigid part 3 in the operative position, is positioned on the outside or is the furthest distant from the part 3. A similar arrangement is provided on both the top and bottom of the part 3, the upper part opens to the left and the lower part opens to the right with the open side of the boxes 13 providing the space through which the auxiliary outrigger sections extend from the parts 3.

When the auxiliary outrigger sections are originally folded into the inoperative position, the stabilizing tubular members 7 are folded over in double layer strips. As shown in FIG. 4, a thin wall tube 15 of polyamide is inserted into the tubular members. This thin wall tube 15 serves as a passageway for pressurized gas which unfolds the auxiliary outrigger section 6. The pressurized gas is received from a central gas system located within the space vehicle. As the auxiliary outrigger sections unfold laterally outwardly from the main outrigger section, the circular cross-section of the tubular member 7 is provided by the inflation of the thin wall tubes to their normal circular cross-section, as shown in FIG. 5.

Covering the exterior of the stabilizing tubular members 7 is a sheet 16 of polyamide. The sheet 16 prevents freezing of water in which the material of the tube has been steeped to make it flexible, however, the sheet does not prevent the evaporation of the water which affords the rigidity of the tubular member 7 so that the auxiliary outrigger sections form a continuation of the plane of the main outrigger section.

As an alternative to the inoperative position of the outrigger shown in FIGS. 1 and 3 the outrigger 2 can be provided with hinges 17 for connecting the parts 3 of the main outrigger section together. In this arrangement, as represented in FIG. 6, the parts 3 of the main outrigger section are wound or wrapped in a polygonal course about the outer surface of a space vessel 18. While only a single course is shown disposed about the vehicle 18 it would also be possible to wrap the outrigger 2 in several layers about the vehicle. When the outrigger is opened from its wrapped position about the space vehicle a cable line 19 operated by means of a motor extends the parts 3 into the operating position outwardly from the vehicle. In addition, the opening operation can also be effected by prestressed lockable springs 20 or by centrifugal forces.

In another embodiment of the invention, as shown in FIG. 7, the main outrigger sections are made up of parts 21 of equal length extending outwardly from the polygonal shaped space vehicle 24. Projecting outwardly from each side of the main outrigger section formed by the parts 21 is an auxiliary outrigger section 22. As illustrated in the lower portion of FIG. 7, where one of the outriggers is shown in full lines in its extended operating position, a stabilizing tubular member 7 extends laterally from each of the parts 21 being secured to the part 21 at the corner of its edge spaced more remote from the vehicle 24. Accordingly, a plurality of tubular members extend laterally from the main outrigger section and are spaced apart approximately the same distance as the length of each of the parts 21. The length of the stabilizing tube members 7 is an integral multiple of the

3,606,211 width of the parts 21, see FIG. 8. Extending outwardly from the main outrigger section and secured to the tubular members 7 is a sheet of a flexible material, as disclosed above, which forms the support surface for the auxiliary outrigger sections 22. At the ends of the tubular members 5. 7 are provided inflatable tubes 10' made of polyamide acting as spacers for tubular members 7.

In FIG. 8, the arrangement of the auxiliary outrigger sections in the inoperative position are shown in a folded over interleaved assembly resting on the surfaces of the 10 parts 21. As displayed by the dot-dash lines designated by the reference numeral 22 in FIG. 8, the portions of the auxiliary outrigger section located closest to the main outrigger section in the opened operative position are located on the outer part of the folded construction. In 15 the inoperative position the outriggers are wound or wrapped in a specially provided and correspondingly dimensioned recess in the space vehicle 24 in such a way that the parts 21 are located outwardly and the auxiliary outrigger sections are located between the parts 21 and 20 the surface of the space vehicle 24. Accordingly, the auxiliary outrigger sections are protected against displacement and friction damage due to the acceleration of the space vehicle. The parts 21 of the main outrigger section are locked in place by spring locks 25, which can be 25 opened by explosive means or by an unfolding mechanism.

In the embodiment shown in FIG. 7, with the outrigger being opened into the operative position, the main outrigger sections are unwound or rolled out of the recess 30 23 in the vehicle by means of a lifting cable with each part of the main outrigger section acting as a lever arm. While the main outrigger section is being opened, the auxiliary outrigger sections 22 remain secured on the parts 21 by bands 26, shown schematically in FIG. 7. 35 After the main outrigger section has been extended for its full length the bands 26 are loosened by the lifting cable, and then the auxiliary outrigger sections are opened laterally outwardly from the main outrigger section by inflating the polyamide tubes ,15 within the stabilizing 40 tubular member 7 by supplying a pressurized gas into them from a central pressurized gas system located in the space vehicle 24.

In FIG. 9, still another embodiment of the invention is illustrated, and it has the distinguishing characteristic that the parts 31 of the main outrigger section are of 45 unequal length. As can be seen in FIG. 11, the parts 31 are connected together alternately by side bars 32 and by hinges 33 in such a way that the parts can be opened from the inoperative to the operative position so that the parts are disposed relative to one another by 90 or 180 50 degrees. On the outer surfaces of the parts 31 a lifting cable 37 is provided.

Extending laterally from each side of the main outrigger section is an auxiliary outrigger section 36, the auxiliary outrigger sections 36 are supported from the 55 edges of the parts 31 by means of first tubular members 7 and second tubular members 34. The first tubular members are attached at the innermost end and at the outermost end of parts 31 forming the inner and outer edges of the auxiliary outrigger section. Located at spaced loca- 60 tions between the first tubular members are second tubular members 34 extending outwardly from the sides of the parts 31 to the outer edge of the auxiliary outrigger section. The second tubular members are secured to the parts 31 at the location of a joint between two adjacent 65 parts 31. The first tubular members 7 have a uniform circular cross-section throughout their length. However, the second tubular members 34 are reinforced at their inner ends adjacent the parts 31 so they have a conically appearing shape with a decreasing cross-sectional size as 70 they proceed outwardly from the main outrigger section. In each of the first and second tubular members 7 and 34, a thin tube 35 formed of polyamide is located. As in the other embodiments previously described, a sheet of flexible material such as a sheet of polyamide extends 75 across and is supported by the first and second tubular members 34 which provide a stabilizing and supporting effect for the sheet.

In FIG. 10, the arrangement of the outrigger illustrated in FIG. 9 is shown in the inoperative or folded position with each of the oppositely extending auxiliary outrigger sections being folded in an interleaved arrangement supported on the parts 31 of the main outrigger section. In this interleaved folded arrangement the auxiliary outrigger sections can be easily unfolded by means of the pressurized gas conducted through the tubes 35 to the ends of the stabilizing tubular members 7 and 34 remote from the main outrigger section. As indicated in FIG. 10, the unfolding operation begins with the outer ends of the auxiliary outrigger sections with the two oppositely extending outrigger sections opening in an alternating arrangement. In FIG. 11, the parts 31 of the main outrigger section, which are of unequal length, are wound in a manner similar to a rolling shutter with the outermost part 31 being located in the center of the rolled arrangement. As is readily apparent in FIG. 11, the length of the unequal parts 31 corresponds to the dimensions of the rolled arrangements.

The unfolding or unrolling of the main outrigger section is performed, for example, by the lifting cable 37 shown in FIG. 11. In addition, this embodiment of the outrigger could be wound in a polygonal course about the space vessel 18 and the folding pattern illustrated in FIG. 10 would still be the same.

If two outriggers are wound symmetrically about the space vehicle, the unfolding of the main outrigger sections can be controlled synchronously by lifting cables. The interfering influences of the space vehicle are minimal.

While the outriggers described above have been mentioned as a support arrangement for solar cells, it will be readily apparent that they can also be used as antennas, reflectors and the like.