Deployable boom and deployable boom with solar blanket

This application claims the benefit of U.S. Provisional Patent Application No. 62/188,373 entitled “DEPLOYABLE BOOM AND DEPLOYABLE BOOM WITH A SOLAR BLANKET” and filed on Jul. 2, 2016 for Thomas J. Harvey, et al., which are incorporated herein by reference in its entirety.

The invention relates to a deployable boom that can transition from a stowed/undeployed state to an unstowed/deployed state.

Generally, a boom is a pole-like structure that is used to lift or support a load. The boom extends from a first terminal end to a second terminal end. In one type of boom, the first terminal end is adapted to engage a platform and the second terminal end is adapted to move relative to the first terminal end. The engagement between the first terminal end of the boom and the platform may be rigid such that the boom has no rotational degrees of freedom relative to the platform or from one to three rotational degrees of freedom relative to the platform.

In one type of boom, the second terminal end of the boom can be moved towards or away from the first terminal end of the boom. A first sub-type of boom in which the second terminal end can be moved in this manner is a hinged boom. A hinged boom includes a first sub-boom that defines the first terminal end of the boom, a second sub-boom that defines the second terminal end of the boom, and a hinge structure that connects the first and second sub-booms and allows rotational movement between the first and second sub-booms.

A second sub-type of boom in which the second terminal end of the boom can be moved relative to the first terminal end of the boom is a telescoping boom. In a telescoping boom the second terminal end of the boom is adapted to move linearly relative to the first terminal end of the boom. In one embodiment, the telescoping boom is comprised of two sub-booms, the first sub-boom defining the first terminal end of the boom and the second sub-boom defining the second terminal end of the boom. The first sub-boom defines a hollow space that is capable of accommodating a substantial portion of the length of the second sub-boom. A motor system (hydraulic, pneumatic, mechanical etc.) is employed to extend and retract the second sub-boom relative to the first sub-boom. Telescoping booms with more than two sub-booms are also known.

A third sub-type of boom in which the second terminal end of the boom can be moved relative to the first terminal end of the boom is a telescoping boom in which the second terminal end of the boom: (a) moves linearly relative to the first terminal end of the boom and (b) rotates about the longitudinal axis of the boom during any linear movement. In particular embodiments of this type of boom, the boom is a lattice/truss structure comprised of multiple longerons that generally extend in the longitudinal direction of the lattice/truss structure, multiple battens that each engage the longerons and extend substantially transverse to the longerons, and multiple diagonals that each extend between two consecutive battens such that the diagonal is not substantially perpendicular to either the battens or the longerons. In one particular embodiment, the longerons are each continuous between the first and second terminal ends. Each longeron is made of a material that allows the longeron or any portion of the longeron to be placed in a first unstrained state or a second strained state. When such a longeron or a portion of the longeron is in the first unstrained state, the longeron or portion of the longeron extends linearly and is capable of maintaining this shape over a range of loads. When the longeron or portion of the longeron is in the second strained state, the longeron or portion of the longeron has been subjected to a force that has caused the longeron or portion of the longeron to adopt a curved shape and store strain energy. The battens are also capable of being deformed between such first and second states. The diagonals are typically made of a flexible material (e.g., thread, wire etc.). The deformable nature of the longerons and battens allows the truss to be coiled. Further, the strain energy stored in the longerons and, to a lesser extent, the battens allows the truss to self-deploy such that the second terminal end of the truss moves linearly away from the first terminal end of the truss and, in so doing, also rotates about a longitudinal axis between the first and second terminal ends. Examples of this type of telescoping boom can be found in U.S. Pat. No. 3,486,279 and U.S. Pat. No. 4,866,892.

In another embodiment of a boom in which the second terminal end of the boom moves linearly relative to the first terminal end of the boom and rotates about the longitudinal axis of the boom during any such linear movement, each of the longerons is comprised of sub-sections that are connected to one another by lockable hinges. When the hinges are unlocked, the longerons and the truss can be coiled. When the hinges are locked, the longerons extend linearly. This particular embodiment of a telescoping boom does not store energy in the longerons or battens when coiled. As such, this particular embodiment of a telescoping boom requires some kind of motor mechanism to move the second terminal end of the boom relative to the first terminal end of the boom.

The present invention is directed to a deployable tape boom that is capable of transitioning from a stowed/undeployed state to an unstowed/deployed state. In one embodiment, the deployable tape boom includes: (a) a perforated tape that extends from a first terminal end to a second terminal end and when deployed or partially deployed serves as a longeron of the boom, (b) a drive mechanism that includes a sprocket with teeth or cogs that engage the perforations in the tape and a motor mechanism for producing and transmitting the force that is used to rotate the sprocket, and (c) two battens that each engage the perforated tape and provide an interface for engaging a load (e.g., a solar array structure). The first batten is rigidly attached adjacent to the first terminal end of the tape. The second batten is defined by: (a) whatever cog of the sprocket mechanism is engaging a perforation in the tape, where the engaged perforation is the closest perforation to the first terminal end of the tape that is engaged by a cog and (b) the structure that is supporting the sprocket mechanism. The battens, in this particular embodiment, are not conventional battens because there is only one longeron. In the stowed/undeployed state, the sprocket mechanism is engaged with perforations closer to the first terminal end of the tape than the second terminal end of the tape and the boom extends from the first terminal end of the tape to the perforation in the tape that is engaged by the sprocket and closest to the first terminal end of the tape. To deploy the tape boom, the motor mechanism is used to rotate the sprocket, thereby causing the deployable tape boom to transition from the stowed/undeployed state towards the unstowed/deployed state. More specifically, rotation of the sprocket causes the first terminal end of the tape to move farther from the sprocket and the sprocket to engage a perforation or perforations in the tape that are farther from the first terminal end of the tape. The boom now extends from the first terminal end to the perforation that is engaged by the sprocket and closest to the first terminal end. Depending on the load being supported by the deployable tape boom, the drive mechanism can also be used to transition the boom from an unstowed/deployed state towards the stowed/undeployed state.

In another embodiment, the deployable tape boom includes (a) a perforated tape that extends from a first terminal end to a second terminal end and when deployed or partially deployed serves as a longeron of the boom, (b) a drive mechanism that includes a sprocket with teeth or cogs that engage the perforations in the tape and a motor mechanism for producing and transmitting the force that is used to rotate the sprocket, and (c) three or more battens that each engage the perforated tape and provide an interface for engaging a load (e.g., a solar array structure). The first batten is rigidly attached adjacent to the first terminal end of the tape. The second batten is defined by: (a) whatever cog of the sprocket mechanism is engaging a perforation in the tape, where the engaged perforation is the closest perforation to the first terminal end of the tape that is engaged by a cog and (b) the structure that is supporting the sprocket mechanism. However, at least a third batten is disposed between the first and second battens. The third batten is a sliding batten, i.e., a batten through which the tape can slide until a certain length of tape has been deployed. At that point, the location of the batten is fixed relative to the tape. In one embodiment, the location of the batten is at least partially fixed by a lanyard that extends from the sliding batten to a preceding batten (i.e., a batten that is closer to the first terminal end of the tape than the sliding batten). To elaborate, when a certain length of tape has been deployed, the lanyard between the sliding batten and the preceding batten comes taut, thereby at least partially fixing the position of the sliding batten, i.e., the sliding batten is prevented from moving farther away from the preceding batten. In yet another embodiment, the location of the sliding batten is fixed by a detent mechanism that engages one of the perforations in the tape. In yet another embodiment, both a lanyard and a detent are employed to fix the location of a sliding batten relative to the tape.

In a particular embodiment, the deployable tape boom includes a load in the form of a solar array blanket. The solar array blanket, in one embodiment, is comprised of at least four solar panels with intermediate hinge joints between the panels that allow the blanket to be placed in a stowed/undeployed state by Z-folding. In the case of a solar array blanket comprised of four solar panels, three intermediate hinge joints are employed, a first intermediate hinge joint to connect the first panel to the second panel, a second intermediate hinge joint to connect the second panel to the third panel, and a third intermediate hinge joint to connect the third panel to the fourth panel. A first outer hinge joint that is associated with the first solar panel connects the solar array blanket to the first batten that is rigidly attached adjacent to the first terminal end of the tape. A second outer hinge joint that is associated with the fourth solar panel connects the solar array blanket to the second batten defined by the cogs of the sprocket mechanism. The second intermediate hinge joint between the second and third panels is connected to the sliding batten that is located in between the first and second battens. Connecting the solar array blanket to the deployable boom in this manner allows the load of the deployed solar array blanket to be distributed at three locations along the longitudinal extent of the deployed boom instead of at just the two locations that many known booms engage the opposite outer edges of a deployed solar array blanket.

In another embodiment, a deployable tape boom includes: (a) two or more perforated tapes that each extend from a first terminal end to a second terminal end and when deployed or partially deployed serve as a longerons of the boom, (b) a drive mechanism that includes a sprocket mechanism for engaging each of the perforated tapes and a motor mechanism for producing and transmitting the force that is applied to the sprocket mechanism to move the first terminal end of each of the perforated tapes relative to the sprocket mechanism, and (c) two or more battens that each engage the perforated tapes and provide an interface for engaging a load (e.g., a solar array structure). Since the perforated tapes form longerons in the deployed state and the battens extend between the longerons, the battens in this embodiment are convention battens. In an embodiment employing two battens, the first batten is rigidly attached adjacent to the first terminal end of the tape. The second batten is defined by: (a) whatever cog of the sprocket mechanism is engaging a perforation in the tape, where the engaged perforation is the closest perforation to the first terminal end of the tape that is engaged by a cog and (b) the structure that is supporting the sprocket mechanism. In embodiments that employ three or more battens, there is at least a third batten located between the first and second battens that is a sliding batten. When three or more battens are employed, the location of any sliding batten is at least partially fixed by a lanyard that extends from the sliding batten to a preceding batten. In certain embodiments, the lanyard that extends between a sliding batten and another batten and serves to at least partially fix the position of the sliding batten relative to the tape also serves, when taut, as a diagonal in the boom structure. A detent mechanism can also be employed to facilitate the fixing of the location of a sliding batten relative to the tape. Further, a combination of a lanyard/diagonal and detent mechanism can be employed to fix the location of a sliding batten relative to the tape. In a particular embodiment, the deployable tape boom includes a cassette for each lanyard that stores the lanyard when the boom is in an undeployed state and gradually feeds the lanyard out during deployment, thereby preventing the lanyard from engaging other structures and potentially fouling the deployment.

In one embodiment that employs three of more battens and three or more tapes, the stowed/undeployed state is characterized by the battens being positioned so as to form a laminate structure with a height that is substantially equal to the cumulative thicknesses of the battens. To deploy the tape boom from this stowed/undeployed state, the motor mechanism applies force to the sprocket mechanism, thereby causing each of the three or more perforated tapes to transition from the stowed/undeployed state towards the unstowed/deployed state. More specifically, actuation of the sprocket mechanism causes the first terminal end of each of the tapes to move farther from the sprocket mechanism and the sprocket mechanism to engage perforations in the tapes that are farther from the first terminal ends of the tapes. Initially, the tapes are sliding through each of the sliding battens. Eventually, the first terminal ends of the tapes reach a distance from the sprocket mechanism at which the lanyard/diagonal structure extending between the first batten and the sliding batten that was immediately adjacent to the first batten in the laminate structure comes taut. Further deployment of the tapes results in the sliding batten being separated from the next underlying batten. Yet further deployment of the tapes results in the diagonal structure extending between the sliding batten and the next underlying batten coming taut. If the next underlying batten is the second batten, then the deployment is complete. If the next underlying batten is a sliding batten (i.e., a second sliding batten), then further deployment of the tapes results in the diagonal structure between the first and second sliding battens causing the second sliding batten to be separated from the next underlying batten. The deployment of the tapes continues until the diagonal structure extending between the last sliding batten and the second batten comes taut.

FIGS. 1A-1D shown an embodiment of the deployable boom transitioning from a fully stowed/undeployed state to a fully unstowed/deployed state;

FIG. 2A shows the first batten and related structure of the embodiment of the boom shown in FIGS. 1A-1D ;

FIG. 2B shows the sliding batten and related structure of the embodiment of the boom shown in FIGS. 1A-1D ;

FIG. 3 is a schematic diagram of the drive or motor mechanism employed in the embodiment of the boom shown in FIGS. 1A-1D ;

FIGS. 4A and 4B illustrate one of the tape cassettes employed in the drive mechanism schematically illustrated in FIG. 3 ;

FIG. 5 illustrates the sliding batten used in the embodiment of the boom shown in FIGS. 1A-1D ;

FIGS. 6A and 6B respectively illustrate the exterior of a detent mechanism and a cross-section of the detent mechanism this is employed in the sliding batten shown in FIG. 5 ;

FIG. 7A illustrate the detent mechanism illustrated in FIGS. 6A and 6B operatively attached to the sliding batten;

FIG. 7B illustrates the detent mechanism, sliding batten, and tape of FIG. 7A in cross-section;

FIG. 8A illustrates one of the two double-barrel hinges used to connect the sliding batten to a solar blanket;

FIG. 8B illustrate the other one of the two double-barrel hinges used to connect the sliding batten to the solar blanket;

FIGS. 9A-9E illustrates another embodiment of a deployable boom with a solar blanket that includes a number of panels that deploy in a first dimension and a number of panels that deploy in a second dimension; and

FIG. 10 illustrates the use of flex circuits to serve as diagonals and to provide a structure for conveying electrical signals to and/or from an electrical device associated with the boom.

With reference to FIGS. 1A-1D and 2A-2B , an embodiment of a deployable tape boom 20 that is capable of transitioning between a stowed/undeployed state to an unstowed/deployed state is described. Generally, the deployable tape boom 20 (hereinafter “boom 20 ”) includes (a) perforated tapes 22 A- 22 C that each extend from a first terminal end to a second terminal end, (b) a drive mechanism 24 for use in transitioning the tapes 22 A- 22 C between an undeployed state and a deployed state in which at least a portion of each the tapes extends linearly from its first terminal end towards its second terminal end, (c) a first batten 26 A that is fixedly engaged to each of the perforated tape 22 A- 22 C adjacent to the first terminal ends of the tapes, (d) a second batten 26 B that is formed (at least in part) by the structures of the drive mechanism that are engaging the perforated tapes 22 A- 22 C at any point in time, (e) a sliding batten 26 C that is located between the first and second battens 26 A, 26 B, (f) a diagonal system 28 that includes a first set of flexible filaments that diagonally extend between the first batten 26 A and the sliding batten 26 C when deployed, a second set of flexible filaments that extend between the second batten 26 B and the sliding batten 26 C when deployed, and a first set of three cassettes 30 A and a second set of three cassettes 30 B, with each cassette adapted to store two of the flexible filaments when the boom 20 is in a stowed/undeployed state and to dispense the two filaments when the boom is transitioning between the stowed/undeployed and unstowed/deployed states.

Each of the deployable tapes 22 A- 22 C is a type of tape that is commonly referred to as a carpenter's tape, i.e., a tape that (a) longitudinally extends from a first terminal end to a second terminal end (b) is capable of being placed in a Archimedean spiral roll with the first terminal end being located on the outermost portion of the roll and the second terminal being located on the innermost portion of the roll; (c) is capable of being partially or completely unrolled, (d) has a lateral cross-section that is linear at any rolled portion, and (d) has a lateral cross-section that is curved at any unrolled portion. Each of the tapes 22 A- 22 C in boom 20 is made from steel. Other materials can be used for the tapes. In a preferred embodiment, each of the tapes is made from a carbon-fiber composite that, in addition to having the aforementioned properties of a carpenter's tape, also has two stable phases. The first stable phase is characterized by the entire tape in a rolled state. The second phase is characterized by the entire tape being in the unrolled state. If such a tape is partially unrolled (i.e., in an intermediate state), the tape will self-transition towards one of the two stable states. Such a tape is desirable in outer space related applications and other applications in which the boom may need to be in a stowed/undeployed state for a considerable period of time. In such situations, the tapes will likely be in the first stable phase or in an intermediate phase in which the tape will attempt to self-transition towards the first stable phase. As such, little or no energy needs to be expended in keeping the tape in this undeployed or substantially undeployed state. While the boom 20 utilizes the three tapes 22 A- 22 C, it should be appreciated that a boom that utilizes four or more tapes is also feasible.

With reference to FIGS. 3, 4A, and 4B , the drive mechanism 24 includes three tape cassettes 36 A- 36 C that are each adapted to store one of the tapes 22 A- 22 C or a substantial portion of such a tape in a rolled state. Further, each of the cassettes 36 A- 36 C includes sprocket wheel 38 disposed on a drive axle 40 . Each sprocket wheel 38 has a plurality of cogs extending outwards from the wheel with each cog sized to engage the perforations in the associated tape stored in the cassette. Rotation of the sprocket wheel 38 about the drive axle 40 in one direction causes the first terminal end of the relevant tape to move away from the cassette. Rotation of the sprocket wheel in the opposite rotational direction causes the first terminal end of the relevant tape to move towards the cassette. Associated with the drive axle 40 of one of the tape cassette 36 A are a drive gear 42 and a drive motor 44 with a drive shaft 46 . The drive motor 44 includes a worm gear 48 that is operatively engaged to the drive shaft 46 . The drive motor 44 operates, via the drive shaft 46 , worm gear 48 , and drive gear 42 to provide rotational force (clockwise and/or counter-clockwise) to the drive axle 40 and the sprocket wheel 38 to linearly move the first terminal end of the tape in the desired direction. The drive motor 44 , in addition to being controllable as to the direction of rotation, can also be controlled as to rotational speed.

The drive axle 40 of the of the tape cassette 36 A is coupled to the drive axles of the tape cassettes 36 B, 36 C by a transmission system that applies the rotational force produced by the drive motor 44 to the sprocket wheels associated with the tape cassettes 36 B, 36 C and synchronizes the movement of the tapes with one another. The transmission system include a first transmission axle 50 A, a first u-joint 52 A that connects the drive axle 40 of the tape cassette 36 A and the first transmission axle 50 A, and a second u-joint 52 B that connects the first transmission axle 50 A to the drive axle 40 of the tape cassette 36 B. The transmission system also includes second transmission axle 54 A, a first u-joint 56 A that connects the drive axle 40 of the tape cassette 36 A and the second transmission axle 54 A, and a second u-joint 56 B that connects the second transmission axle 54 B and the drive axle 40 of the tape cassette 36 C. Other structures known to those skilled in the art can be used to synchronize the extension/retraction of the tapes 22 A- 22 C to/from the tape cassettes 36 A- 36 C.

With reference to FIG. 2A , the first batten 26 A is a triangularly shaped member that is fixedly engaged to each of the tapes 22 A- 22 C adjacent to the first terminal end of each of the tapes. The first batten 26 A, in the illustrated embodiment, is made of aluminum. However, other materials, such as carbon-fiber, can also be employed.

With reference to FIGS. 1D and 2B , the second batten 26 B is defined by: (a) the cog associated with each of the three sprocket wheels that is engaging a perforation in one of the three tapes 22 A- 22 C and, because several cogs associated with a wheel may be engaging a tape at any given time, the cog that is engaging the perforation closest to the first terminal end of the tape and (b) the structure that is supporting the cogs wheels. Because the sprocket wheels rotate to move the tape, it should be appreciated that the cogs that define the second batten 26 B change during movement of the tape. However, the position of the second batten 26 B relative to whatever structure is supporting the tape cassettes 36 A- 36 C is substantially static whether the tapes are moving or not moving relative to the cassettes.

With reference to FIG. 5 , the sliding batten 26 C is a triangularly shaped member with three arc-shaped holes 60 A- 60 C, one located at each of the three corners of the batten. The arc-shaped holes 60 A- 60 C respectively engage deployed (linear) portions of the three tapes 22 A- 22 C in a manner that allows the tapes to slide through the holes. Associated with the sliding batten 26 C are three detent mechanisms, one associated with each of the three corners of the batten. Each of the three detent mechanisms is adapted to engage the perforations in one of the three tapes 22 A- 22 C. With reference to FIGS. 6A-6B and 7A-7B , the detent mechanism 62 A that is adapted to engage perforation associated with tape 22 A is described with the understanding the other two detent mechanisms are substantially identical. The detent mechanism 62 A is comprised of a housing 64 with an exterior thread 66 and a hollow interior space 68 that supports a ball 70 and spring 72 that biases the ball away from the housing. The exterior thread 66 of the housing 64 is adapted to engage a threaded hole 74 that extends from the exterior of the batten 26 C to the arc-shaped hole 60 A. The detent mechanism 62 A operates so that the spring 72 forces the ball 70 into each perforation of tape 22 A when the tape is moving relative to the sliding batten 26 C. However, the movement of the tape 22 A will apply enough force to the ball 70 and to the spring 72 so as to compress the spring and allow the ball to be displaced out of a perforation. Once the tape stops moving, the spring 72 will bias the ball 70 into any perforation that is substantially aligned with the ball 70 when movement of the tape 22 A ceases.

The diagonal system 28 is comprised of a first set of three pairs of crossing diagonal members 80 with each pair of crossing diagonal members extending between and engaging the first batten 26 A and the sliding batten 26 C and a second set of three pair of crossing diagonal members 82 with each pair of crossing diagonal members extending between and engaging the second batten 26 B and the sliding batten 26 C. Each diagonal member is made from a flexible filament (e.g., wire, thread, carbon-fiber thread etc.). As such, each diagonal member functions as diagonal in a truss when the member becomes taut. The first set of diagonal members, in addition to providing an element of truss when taut, also partly fixes the position of the sliding batten 26 C relative to the tapes 22 A- 22 C. To elaborate, at a predetermined point during the deployment of the tapes 22 A- 22 C, the first batten 26 A has been displaced a distance from the sliding batten 26 C at which the first set of three pairs of crossing member come taut. At this point, the tapes 22 A- 22 C can no longer slide through the arc-shaped holes 60 A- 60 C of the sliding batten 26 C. As such, the position of the sliding batten 26 C is partially fixed because the sliding batten 26 C is prevented from moving farther away from the first batten 26 A by the first set of three pairs of crossing diagonal members that are now taut. At this point, each of the tapes 22 A- 22 C also has a perforation that is substantially aligned with the ball of the corresponding one of the detents 62 A- 62 C. As such, the detents 62 A- 62 C also operate at this point to fix the sliding batten 26 C in place relative to the tapes 22 A- 22 C such that the batten is substantially prevented from moving either towards or away from the first batten 26 A. In certain embodiments, the first set of crossing diagonal members 80 may sufficiently fix the sliding batten 26 C in place relative to the tapes 22 A- 22 C and the detents 62 A- 62 C considered unnecessary. It should also be appreciated that at this point, a truss structure comprised of a first bay has been formed. A bay is comprised of two consecutive battens, the longerons extending between the two consecutive battens, and the diagonals extending between the two consecutive battens. The first bay is comprised of the first batten 26 A and sliding batten 26 C, the longerons formed by the linear portions of the tapes 22 A- 22 C that extend between these two battens, and the deployed first set of three pairs of crossing diagonal members 80 (now taut). Further deployment of the tapes results in the formation a truss structure comprised of two bays, the first bay and a second bay that is defined by the sliding batten 26 C and the second batten 26 B, the longerons formed by the linear portions of the tapes 22 A- 22 C that extend between these two battens, and the deployed second set of three pairs of crossing diagonal members 82 (now taut). It should be appreciated that, in certain embodiments, one or more diagonals that extend over two or more bays may be desirable. Further, other embodiments that employ four or more tapes, may employ one or more diagonals that extend across the interior space defined by the deployed tapes. For instance, in a four tape embodiment, such diagonals could define an X-shape when viewed from the end of the deployed boom. In a five tape embodiment, such diagonals could extend from a point adjacent to a first tape to points adjacent to the third and fourth tapes (when moving clockwise/counter-clockwise from the first tape) thereby have a five-pointed star-shape when viewed from the end of the deployed boom.

In the illustrated embodiment, the boom 20 is supporting a load in the form of a solar array blanket 90 that is comprised of four solar panels 92 A- 92 D with consecutive pairs of the panels connected to one another with intermediate hinge joints that allow the blanket to be placed in a stowed/undeployed state by Z-folding. The stowed/undeployed blanket 90 has a laminate characteristic as shown in FIG. 1A . In a preferred embodiment, each of the solar panels has a single-piece panel that supports one or more solar cells and has a shallow V-shape that renders the panel relatively stiff and provides other advantages. An example of such a solar panel is described in U.S. patent application Ser. No. 14/447,350, which is incorporated herein by reference in its entirety.

The boom 20 is engaged to the solar array blanket 90 with three hinge structures that are associated with the first batten 26 A, second batten 26 B, and sliding batten 26 C. With reference to FIG. 2A , the first hinge structure is comprised of two aligned barrel hinges 100 A, 100 B. The barrel hinges 100 A, 100 B are respectively comprised of: (a) L-shaped leafs 102 A, 102 B that each have a first end that is connected to the first batten 26 A and a second end that forms a barrel structure, (b) panel leafs 104 A, 104 B that are each connected to the solar panel 92 A and define a barrel structure that cooperates with the barrel structure of the corresponding L-shaped leaf, and (c) pins that extend through the aligned barrels of leafs 100 A, 104 A and the aligned barrels 100 B, 104 B. With reference to FIG. 1C , the second hinge structure comprised of two aligned barrel hinges connects the second batten 26 B (which includes structure that supports the sprocket wheels) to panel 92 D. With reference to FIGS. 8A and 8B , the third hinge structure is comprised of two aligned double-barrel hinges 106 A, 106 B that each connects the sliding batten 26 C to both panel 92 B and panel 92 C. The double-barrel hinges 106 A, 106 B respectively employ (a) L-shaped leafs 108 A, 108 B that each have a first end that is connected to the sliding batten 26 C and a second end that forms a pair of parallel barrel structures, (b) double panel leafs 110 A, 110 B that each have a leaf with a barrel structure that is connected to solar panel 92 B and another leaf with a barrel structure that is connected to solar panel 92 C, and (c) pins that extend through the two groups of aligned barrels associated with each of the hinges 106 A, 106 B.

It should be appreciated that the boom 20 is capable of being adapted to support structures other than a solar blanket. For instance, the boom 20 can be adapted to support a deployable antenna that, like the solar blanket 90 , is supported at multiple points along the length of the boom. As another example, the boom 20 can be adapted to support a measurement instrument located at the end of the boom 20 or at a location intermediate the ends of the boom. The boom is also adaptable to support multiple structures along its length. For instance, the boom 20 can be adapted to support a solar array and an antenna or other instrument.

The boom 20 is capable of realizing an expansion ratio (ratio of the height of the deployed boom to the height of the undeployed boom) of at least 35:1. To elaborate, the height of the stowed/undeployed boom 20 is substantially determined by the sum of (a) the height of the battens 26 A- 26 C when stowed (i.e., when the battens form the laminate structure shown in FIG. 1A ) and (b) the diameter one of the stowed/undeployed tapes 22 A- 22 C. In the fully deployed state, the height of the boom 20 is substantially the length of one of the deployed tape 22 A- 22 C. Due to the relatively small height of the undeployed boom and the significant length of tape that can be disposed in an Archimedean roll, the boom 20 realizes a significant expansion ratio, namely, at least 35:1.

With reference to FIGS. 9A-9E , another embodiment of a deployable boom with a blanket solar array 120 (hereinafter “boom 120 ”) is described. The boom 120 includes three perforated tapes, a drive mechanism, multiple battens with one batten being a sliding batten, and a diagonal system (collectively referred to as deployment mechanism 122 ) and a solar array blanket 124 . The noted elements of the deployment mechanism 122 are substantially identical to those described with respect to the boom 20 . However, the solar array blanket 124 is different than the solar array blanket 90 . To elaborate, the solar array blanket 124 includes four panels just like solar array blanket 90 . These are central panels 126 A- 126 D. Each of the central panels 126 A- 126 D is of the type of panel taught in U.S. patent application Ser. No. 14/447,350 (which is incorporated herein by reference), characterized as being relatively stiff and having a shallow-dished or shallow V-shape. The solar blanket 124 includes a first set of wing panels 128 that are pivotally connected to the central panels and a second set of wing panels 130 that are pivotally connected to the central panels. The first set of wing panels 128 includes four wing panels 132 A- 132 D. The second set of wing panels 130 includes four wing panels 134 A- 134 D. Each of the wing panels is of the type of panel taught in U.S. patent application Ser. No. 14/447,350, characterized as being relatively stiff and having a shallow-dished or shallow V-shape. Each of the wing panels is connected to a central panel by a pivotal connection that allows the wing panel to be rotated such that the panel overlies a central panel and can be rotated away from a central panel so as to be disposed substantially planar with the central panel. Associated with the pivotal connection is a bias mechanism that causes the wing panel to rotate away from the central panel when not constrained in the position in which the wing panel is folded over the central panel. Also associated with the pivotal connection is a mechanism that limits the extent to which the wing panel rotates away from the central panel. A pivot connection structure that allows a wing panel to rotate away from a central panel, provides a bias mechanism for causing the rotation, and provides a limit to the extent of the rotation is taught in U.S. patent application Ser. No. 14/447,350 (which is incorporated by reference in its entirety). In the illustrated embodiment, there are pivot connections 136 A, 136 B respectively between wing panels 132 A, 132 B and central panels 126 A, 126 B and pivot connections 138 A, 138 B respectively between wing panels 134 A, 134 B and central panels 126 A, 126 B. Pivot connections are also present between the wing panels and central panels that are not shown.

With reference to FIG. 10 , another embodiment of a deployable tape boom (hereinafter referred to as “boom 150 ”) is discussed. The boom 150 is substantially identical to boom 20 , except that boom 150 does not employ flexible filaments for the diagonals and, as such, avoids the use of cassettes to store and dispense such filaments. Elements in boom 150 that are substantially identical to those in boom 20 are given common reference numbers. The boom 150 includes a first set of the three flex circuit diagonals 152 A- 152 C that each extend between the first batten 26 A and the third batten 26 C and a second set of three flex circuit diagonals 154 A- 154 C that each extend between the second batten 26 B and the third batten 26 C. Each of the flex circuit diagonals 152 A- 152 C and 154 A- 154 C acts like a pair of crossing diagonals (i.e., serves the same function as one of the crossing pairs of filament diagonals in boom 20 ) and provides one or more paths for the transmission of electrical signals between the battens with which the flex circuit is associated. In the illustrated embodiment, each of the flex circuit diagonals 152 A- 152 C and 154 A- 154 C has an hour glass shape and has a crease that allows the flex circuit diagonal to be folded at its narrowest extent. The hour glass shape and crease allows each of the flex circuit diagonals 152 A- 152 C and 154 A- 154 C to be folded and occupy an independent pie slice like portion of the triangular interior space of a batten or pair of battens when the battens are in a stowed state. Further, the hour glass shape of each of the flex circuit diagonals embodies material that occupies the same space as is occupied by a pair of crossing filament diagonals. As such, each of the flex circuit diagonals 152 A- 152 C and 154 A- 154 C is capable of performing substantially the same function as a pair of crossing filament diagonals. While the boom 150 has replaced all of the filament, crossing diagonals of the boom 20 with flex circuits, it should be appreciated that a boom in which there is a combination of diagonals made up filament diagonals and flex circuit diagonals that provide the functionality of a pair of crossing filament diagonal is feasible. For example, a boom made have a single flex circuit diagonal with the remaining diagonals being filament diagonals. Such a single flex circuit diagonal could, for example, be used to transmit electrical signals between two instruments, one instrument associated with one batten and another instrument associated with the adjacent batten. Two or more flex circuit diagonals can be used to transmit electrical signals over two or more bays. For instance, flex circuit diagonals 152 A, 154 A may be embodied in a single flex circuit or operably connected to one another so as to be able to transmit an electrical signal between the first and second battens 26 A, 26 B. Also feasible is an electrical path provided by the flex circuit diagonals that does not extend linearly when the boom 150 is deployed. For instance, a flex circuit or other suitable conductor can be used to electrically connect the flex circuit diagonal 152 B with the flex circuit 154 A. Flex circuit diagonals with other shapes and two or more creases that facilitate accordion folding are also feasible.

The foregoing description of the invention is intended to explain the best mode known of practicing the invention and to enable others skilled in the art to utilize the invention in various embodiments and with the various modifications required by their particular applications or uses of the invention.