Abstract: This convertible structural element comprises two link chains (1, 2) which, after assembly, are capable together of assuming the form of a rigid beam. The links (3, 4) of the two chains are provided with antagonistic bearing points (10, 11), the first bearing point (10) of a link of rank n of each chain interacting with a second bearing point (11) of a link of rank n-1 in order to trap fastening elements which the pins (7, 8) of the links of the other chain form, when the element is made rigid. At least some links of at least one of the chains of the structural element exhibit a row of teeth (13) which, together with the teeth of the neighbouring links in the direction of the length of the element, form a continuous toothing extending laterally over the entire length of the element.

Abstract: A linear actuator has a drum, a stiff flexible ribbon wound on the drum, a device for rotating the drum at least to partially unwind the ribbon thereon, a guide funnel for gradually forming the ribbon into a tubular configuration as it comes off the drum, and an attachment device at a free end of the ribbon for connection to an object to be moved in a linear path. The actuator converts rotary motion to linear motion without the need for complex mechanical linkages.

Abstract: A telescoping mast assembly having a plurality of interconnected mast sections nested within each other is provided. Mast sections move along an axis between retracted and extended positions. A single drive member having a circular shape within the mast sections and connected to one of the mast sections for displacing the sections in opposite directions along the axis is also provided. A contour forming mold for shaping the drive member is provided between the storage reel and the mast sections.

Abstract: A joint for a storable tubular extendible member comprises an input housing with sets of rollers which progressively deform the storable tubular extendible member from its tubular state to a tape-like flat state. An output housing includes rollers allowing the tape-like member to recover to its tubular state. A pivot joins the input and output housings and a plurality of confining members such as nip rollers are provided between the input and output housings to maintain the member in its flat state. The nip rollers are supported by link arms much that some of the rollers may pivot about a pivot on the input housing and others may pivot about a pivot on the output housing. A medial set of nip rollers is constrained to remain medially positioned between the input housing and output housing by having link arms extending from both the input housing pivot and the output housing pivot. A drive is provided to cause the joint to selectively bend.

Abstract: There is provided a panel structure for the side walls of an inground pool, the panel having vertical lines of weakening formed therein permitting it to assume various arcuate configurations, both concave and convex. This arrangement permits a single panel to be used for both straight and curved wall sections.

Abstract: An expandable and collapsible shelter is formed from a series of interconnected expandable and collapsible modules. Each module is formed from interconnected strut pairs pivotably attached at their ends to hub assemblies. The hub assemblies have outer and inner portions that are engageable and disengageable. A pair of struts is placed in a desired angular relationship by a first member for constraining a range of movement of the outer portions of the hub assemblies relative to one another and a releasable member for releasably constraining a range of movement of the inner portions of the hub assemblies relative to one another.

Abstract: A supporting structure of one piece of sheet material constituting a top and several legs depending from that top in one piece has for each of these several legs an angled profile of that one piece of sheet material and in one piece with the top across the entire profile. Such supporting structure may be made of a blank of sheet material forming a pattern having a central portion for the top, first and second portions projecting from a first side of that central portion for first and second legs, third and fourth portions projecting from an opposite second side of the central portion for third and fourth legs, and first and second side panel portions projecting from opposed third and fourth sides of the central portion. These first, second, third and fourth portions are provided, respectively, with lateral ledges of which each is spaced from an adjacent one of the first and second side panel portions by a notch for a butt joint of each of the lateral ledges with an adjacent side panel portion.

Abstract: A structural element is disclosed which is substantially composed of a linked chain and of a flexible connection which can be a chain of identical links and which can be assembled together as required to form a rigid beam. The linked chain comprises opposing support points, the first support point of one link of row n of the chain cooperating with the second support point of a link of row n-1 to contain, while the element is being rendered rigid, hooking elements integral with the flexible connection and which, in the preferred embodiment of the invention, are the pins of the second chain. The structural element can be assembled or disassembled using a special device.

Abstract: The invention relates to an extendable mast or column assembly comprising a pair of interengaging elongate link chains (13, 14), each link chain comprising a plurality of pivotally interconnected chain link elements (17), the adjacent interconnected link elements (17) of the individual chains (13, 14) having interfitting walls which permit relative pivotal movement from an axially in line position in one direction only, at least some of the link elements (17) having abutment surfaces (23, 24, 34) which, when the chains are interengaged, cooperate with one another to provide interlocking means for preventing relative movement between the link elements of one chain and adjacent link elements of the other chain, and chain drive means (46) for interengaging the chains (13, 14) and driving the chains, so interengaged, in an upwards direction to form the rigid mast or column (10). Guy wires (66) may be employed to ensure that the mast (10) is held secure when in an elevated condition.

Abstract: Apparatus for deploying an articulated panel array comprises a spring motor between adjacent panels and a latch between adjacent panels. The latch between a given pair of panels is released by an abutment on the panel which is adjacent to the pair and toward the proximal end of the array only when the more proximally disposed panel of the pair moves to its fully deployed position. With this arrangement, only a single group of panels of the array moves at any given time providing an accurate deployment envelope.

Abstract: A module for forming part of an articulated mast which can be retracted to be stowed and elongated to be deployed, the mast when deployed having a central axis of elongation and a plurality of these modules. Each module has at least three rigid non-folding station rods joined to form a rigid station, and an equal number of non-folding longerons, each hingedly connected to a corner of the station. Four diagonal segments are formed as part of two flexible inelastic cables, which are brought together at a control which always holds one of the cables, and passes the other. The control includes a releasable catch to hold the other cable when its segments are at lengths respective to a deployed module.

Abstract: A mast, column or post is assembled from successive segments which are arrayed along turns of a helix and are connected together successively and to the turns above and below such segments to enable a large diameter mast to be erected and, upon removal of the segments, to be lowered.

Abstract: A stowable and self-deployable array antenna includes flat, rectangular antenna panels hinged side-by-side so that when deployed they are coplanar, and they fold like an accordion for stowing. The deployed array antenna is stiffened by lateral stiffening panels hingedly attached to every other hinge between antenna panels, and to the unhinged ends of the antenna panels. Foldable longitudinal stiffening panels hinged between adjacent lateral stiffening panels. Each hinged connection includes a pair of thin spring elements, corresponding to a portion of a cylinder. The two spring elements of each hinge are spaced apart with their concave sides facing, and with the axes of the defining cylinder parallel. The hinge pivots, when the spring elements buckle, about a line orthogonal to a line extending between the cylinder axes. The hinges are used as the structural elements of self-deployable masts. The mast may have a polygonal cross-section.

Abstract: A foldable dummy object for military camouflage purposes consists of at least three deformable rods (2) which meet at a common point (1) at which they are mutually connected. When the dummy object is deployed, the rods assume and retain the shape of irregular three-dimensional curves, forming an outer rod assembly which can be placed appropriately on the object to be camouflaged, including its corners and edges. The rod assembly comprises a camouflage net which constitutes the definitive outer envelope of the dummy object and also determines its shape. The dummy object is easy to assemble and disassemble and can be trimmed in a known manner with any type of camouflage material. The claim relates to the basic idea and various embodiments.

Abstract: A method and apparatus for assembling an enclosure, in which the assembly includes a coil of material adapted to be uncoiled to an assembling position. The material can be prestressed to become at least transversely curved in the uncoiled assembling position. In a particular embodiment, the material is also prestressed to curve longitudinally, as the coil is unwound to form a toroidal shape. Further, the assembly can include a plurality of elements positioned within the coil, the elements having a size and shape enabling them to be adapted to be affixed to respective parts of the assembly within the enclosure in respective positions along the length of the material in the uncoiled assembling position to constitute an internal structure for the enclosure. The plurality of elements are coiled with the coil of material for permitting access to the elements for assembling them after the material is uncoiled.

Abstract: Disclosed is a building system which utilizes structural modules (10) to form a shelter (89, 132) having a spherical surface. The shelter includes flat portions (A) composed of flat modules (7), arch portions (B) composed of cylindrical modules (8), and spherical triangle portions (C) composed of spherical modules (9). The modules (10) are composed of crossed pairs of struts (13a-16b) which are hingedly interconnected by hubs (18-25). The structural modules preferably include periphery cables (27-30) and diagonal cables (31, 32, 44, 45), each cable being held in place by a cable keeper member (33-36, 46, 47). The structure also features a locking bar mechanism (26) for maintaining the modules (10) in an expanded configuration, and hubs (114) having radial cutout portions (115) for accommodating angular distortion of the structural framework.

Abstract: A mast forming and deployment system comprising a storage reel for storing a strip of sheet metal wound on the reel, and a tube forming a deployment apparatus. The strip is fed to ploy guides that form the sheet metal into a tube with overlapping edges. A drive system feeds the strip of sheet metal to and through the tube forming apparatus and drives staples which hold together the overlapping edges.

Abstract: A mast which is retractable to a lesser height and volume, and deployable to a greater height, and which when deployed can survive a very high temperature event. All structural elements which are required for structural integrity while the mast is deployed are rigid members made of high temperature resistant material. Where the ends of structural diagonals must move toward one another during retraction, that diagonal is provided as a rigid body of two relatively sliding parts which can be latched in an extended condition when the mast is deployed. A lanyard is provided for unlatching and retraction purposes, which may be sacrificed to a high temperature event.

Abstract: A telescoping mast assembly includes a plurality of interconnected mast sections nested within each other for movement between a fully retracted height and a fully extended height. A novel, rigid drive assembly, disposed within the interconnected mast sections, telescopes the mast sections to any position between the fully retracted and the fully extended heights. The rigid drive assembly is constructed of two interconnected, flexible chain elements which accurately position the interconnected mast sections.

Abstract: A deployable and retractable mast which can be rotated while deployed, using only one drive means for all three functions. Flexible longerons carry followers which pass through guides in a storage cannister for transition between a coiled retracted condition and an extended deployed condition. The followers pass through a gate opening, past a gate, and when the mast is rotated, the gates enable or prevent followers from taking the longerons into the retracted condition, and entitles rotation of the mast when retraction is disabled.

Abstract: A structural member is an elongated, generally rectangular panel having at least 2 substantially parallel fold lines extending the length of the panel parallel its long sides, preferably defining 3 subpanels. When the panel is folded along the fold lines, preferably by hand, the interior angles at each fold occur on the same surface of the panel, are approximately 90 degrees, and the member has a generally C-shaped cross-section when folded. At least one male/female lock holds each of the panels at a fixed angle relative to the adjacent panel, each male/female lock having a male component affixed to one of the subpanels and a mating female component affixed to the adjacent subpanel such that when said one subpanel is folded with respect to the adjacent subpanel, the male component inserts into the female component and is retained therein.

Abstract: A toy block comprising:sheet material folded to form a toy block having a plurality of planar surfaces.a plurality of holes formed on at least one of the planar surfaces; anda plurality of protrusions removably retained by the folded sheet material and extending outwardly from at least one of the planar surfaces,whereby the protrusions of one block are arranged for selectable and removable interlocking interengagement with the holes of another block.

Abstract: In a deployable mast composed of: a plurality of resiliently flexible longeron elements; a plurality of resiliently flexible lateral elements arranged in groups of lateral elements constituting batten frames spaced apart along the longeron elements and delimiting respective bays of the mast, with each group of lateral elements being connected to all of the longerons; and a plurality of flexible diagonal elements each connected between two longeron elements and extending between two groups of lateral elements, the longeron, lateral and diagonal elements being constructed and connected to constitute a structure movable between a deployed state defining a column of predetermined length and a stowed state defining a structure having a length less than the predetermined length, there are provided five such longeron elements and each group of lateral elements is connected to all of the longeron elements.

Abstract: An extendable mast of the joint type constructed by freely swingably connecting essentially-rigid members to one another. It includes a plurality of battens extending in the traverse direction of the mast, a plurality of longerons extending in the longitudinal direction of the mast to connect battens adjacent in the longitudinal direction of the mask, and diagonals arranged along the diagonal lines of a rectangle which is formed by the two battens adjacent in the longitudinal direction of the mast and by the two longerons adjacent in the traverse direction thereof. Each of the longerons consists of a pair of beam members freely swingably connected to each other and when these beam members are folded, the mast is also folded compact. The diagonal comprises plural slider members slidable relative to each other and it can be extended to a full length. When these diagonals are extended to their full length, the beam members are locked under overcenter condition.

Abstract: Tetrahedral elements are hingedly connected along opposed edges to form an elongate structure with a pair of cable guides at apices of each pair of connected edges. Cables fixed at or near the apices of the element at the free end of the structure and passing through the guides are used to control the shape of the structure by applying tension at the fixed end of the structure.

Abstract: The extensible support pole unit having a simple structure including a plurality of shaped members, e.g., cylindrical bodies, band-like plates having, e.g., an arched cross-sectional shape, a band-like plate feed mechanism, and a driving device. The support pole is extended to stand or retracted by only paying out or winding up the band-like plates. The support pole can therefore be extended to a length freely selected, and it is possible to freely set a large extension ratio by selecting the length of each cylindrical body and the number of cylindrical bodies. The band-like plates have, for example, an arched cross-sectional shape and have properties such as to be strong against the vertical load as compared with flat plates. The band-like plates are retained in the guide slits or guide holes formed in the partition members disposed in the cylindrical bodies to further improving the above properties.

Abstract: An extensible mast has a computer control for automatically deploying guy cables. As the mast is raised, the cables are deployed at a rate which retains the proper geometric relationships of the system. The system initially calculates the relative locations of the mast and cable anchor points, which can be placed in convenient locations. A winch suitable for use with the system measures the tension on deployed guy cables and the length of cable which has been unwound from the winch drum.

Abstract: A structure comprising a pair of end plates, plural longerons arranged parallel to one another and elastically buckled, a plurality of radial spacers for holding these longerons at a certain interval and a pair of diagonal cords stretched between two adjacent radial spacers, between one of the end plates and the uppermost radial spacer and between the other of the end plates and the lowest radial spacer, respectively, wherein a means is attached to one of the paired diagonal cords stretched between one of the end plates and the uppermost or lowest radial spacer to apply a predetermined tension to this diagonal cord. The transforming of the longerons or radial spacer located at one end of the structure can be restrained by the tension applying means while the structure is being deployed or collapsed.

Abstract: A deployable boom is constructed of springly flexible members so that it is self-biased toward a long length deployed state. A drive mechanism is operative to actuate a reel and lanyard device to retract the boom to a short length storage state and to controllably permit the boom to be extended to its long length deployed state. Latches are operated by the drive mechanism to releasably hold the boom in the short length storage state.

Abstract: Apparatus for pushing a load e.g. a projectile comprises an elongate ribbon which can be extended from a condition where it is coiled on a drum to a substantially straight condition for pushing the load. The ribbon has a generally curved cross section when in its straight condition, and at its front end it has a buffer arranged such that when engaged with the load, the compressive force on the ribbon acts eccentrically so as to deflect the ribbon laterally in a direction towards the center of curvature of the cross section and to bias the ribbon against deflection in the opposite direction.

Abstract: A deployable truss structure desirable for space applications is disclosed. The structure is triangular in cross section, with each longitudinal face of the structure being comprised of parallel longeron members interconnected by parallel batten members, the battens located at the mid-section of each face being non-rigid members, the structure including hinged diagonal members.

Abstract: A retractable support column for overhead structures that comprises there sets of rectangular shaped links that have mating hooks extending laterally outward from adjacent link chains so that the hooks can engage each other when the links are placed vertical next to each other and can disengage each other when the lower link is rotated into a horizontal position with a drive mechanism for engaging gear racks on the link chains to permit the user to raise and lower retractable column.

Abstract: A structure comprising a pair of end plates, plural longerons arranged parallel to one another and elastically buckled, a plurality of radial spacers for holding these longerons at a certain interval and a pair of diagonal cords stretched between two adjacent radial spacers, between one of the end plates and the uppermost radial spacer and between the other of the end plates and the lowest radial spacer, respectively, wherein a means is attached to one of the paired diagonal cords stretched between one of the end plates and the uppermost or lowest radial spacer to apply a predetermined tension to this diagonal cord. The transforming of the longerons or radial spacer located at one end of the structure can be restrained by the tension applying means while the structure is being deployed or collapsed.

Abstract: The subject structure comprises at least one assembly of premanufactured components. Each component comprises at least one beam with a fixture attached at each end. The fixtures are box shaped, having tops, bottoms, ends and side faces. The fixtures are longer (from end to end) than they are high (top to bottom) or thick (face to face) and the faces are perpendicular to the length of the beam. The fixtures are generally symmetrical about a plane perpendicular to and bisecting the faces. Each fixture has a flange extending from one end and a groove in the other. The components are pivotally connected to form an assembly, the pivotal connections being pins inserted through holes to hold the flange of one fixture in the groove of the next, the pin locations being near the tops of the fixtures. The fixtures are frusto-triangular in plan view, the tops being the bases of the triangles. Cables are threaded endwise through the fixtures near their bottoms.

Abstract: A collapsible structural member including a plurality of segmental sections and devices for connecting adjacent segmental sections is disclosed. Each segmental section has a rigid, elongate body portion which terminates in end portions. The connecting devices connect the end portions of adjacent sections so as to define a maximal spacing between the adjacent end portions and to permit them to move between a maximum spaced apart realtionship and an abutting relationship. A quickly erectable shelter and a composite, collapsible support beam are also disclosed according to the present invention. The shelter has a flexible cover, at least one structural member including segmental sections for supporting the cover, connecting devices for connecting adjacent end portions of adjacent segmental sections, and a tensionable cable for moving the sections between a maximum spaced apart relationship and an abutting relationship defined by the connecting devices.

Abstract: An extensible mast is shown which is erected from a portable base having a plurality of tape reels mounted thereon. The tape reels are angularly oriented on the base with respect to a common, vertical axis, and each of the tape reels is adapted to receive a resilient metal tape having longitudinal edges for winding and unwinding the tape. A plurality of guide rollers on the base receive the respective longitudinal edges of the metal tapes and orient the tapes whereby the tapes are fed upwardly in plane parallel to the vertical axis and at an angle to each other to form a rigid structure. A geared winding mechanism is located above the guide rollers and includes a plurality of rotatable windings which rotate about the vertical axis and wrap and wrap material about the rigid structure to reinforce the structure as it is being erected.

Abstract: An extensible structure comprising five or more longerons which can be resiliently deformed like a coil, a plurality of batten members arranged at certain intervals in the axial direction of the longerons to connect the longerons to one another, and two chords diagonally stretched on a plane formed a four connected points where the two longerons with at least one longeron interposed between them are connected by the two batten members adjacent in the axial direction of the longerons.

Abstract: A mast defined by three flexible longerons with cross elements coils into a canister. Extension and retraction are controlled by three axially oriented lead screws which engage protuberances spaced along the longerons. The lead screws are mutually synchronzied by an annular planet gear, and are driven by a spiroidal gear set. At a predetermined mast extension, motor drive is switched over for rotation of the mast rather than extension-retraction. The switch over is controlled by an actuator in the form of a movable guide element dimensioned to clear normal-sized protuberances but to be seized and carried by an oversize protuberance at the desired mast extension. The actuator is coupled to a lock which unlocks the annular gear to the canister so that motor drive results in mast rotation. An auxiliary lock allows re-locking of the canister to the support structure for allowing resumption of the mast extension-retraction mode.

Abstract: A spring apparatus has a spring body including a plurality of elastic longitudinal beam members and a coupling beam member for holding the elastic longitudinal beam members at a predetermined interval. The apparatus further has a pair of spring retaining members for supporting the both ends of the spring body, and a rotary member rotatable provided around the central axis of the spring body as a center at least one one spring retaining member. At least one of the elastic longitudinal beam member is provided at one end of the rotary member. This spring apparatus is a tightly wound coil and made of the elastic longitudinal beam members in fully compressed state. When extended, each elastic longitudinal beam member is sequentially spirally deformed at larger pitch from the end. The twisting deformation of the elastic longitudinal beam member is released by rotation of the rotary member.

Abstract: An extensible mast support system is depicted which utilizes a plurality of anchor points which are disposed radially distant from the base of the mast. A support bracket mounted to the mast serves to mount multiple metering sprockets and a single continuous length of cable is threaded between each anchor point and the support bracket. Strain measurement devices on each span of the cable are utilized to control the length of cable payed out during extension or retraction of the mast. A beaded cable which engages the metering sprockets is utilized to restrict variations in length between spans whereby increased strain in an individual span will not vary the length of the other spans and the mast will remain vertical.

Abstract: Structural members for a frame or truss are formed of two substantially identical elongated tubular like members each having a planar extending wall with the tubular members joined together along the planar wall, "back to back", and end portions of the joined planar walls form extending lugs. A complementary joint fitting includes a clevis having a slot for receiving the lug.

Abstract: A space rail (10) having two basic elements, a box structure (12) which is configured to permit installation of payload hardware and payload services hardware along its length and a deployable back structure (14) which provides stiffness to the assembly of space rails when deployed. The box structure (10) is preferably a flat rectangular frame comprising body members (12) and the back structure (14) comprises a plurality of struts (24a-d, 30) pivotally attached to the body member (14) and to each other so as to fold into a retracted deployable position and to be deployed (unfolded) by a suitable mechanism.

Abstract: There is disclosed a novel articular pole assembly, comprising: an articular pole which is composed of a continuous series of unit block members connected to one another by pins, the unit members each having a main body formed by bending a relatively tough and hard plate material in such a manner that the main body has a channel-like cross-section, each block member also having a connecting plate pivotally supported by the main body at open terminal portions of the main body, the main body having stepped areas where projected parts are present, so that the projected parts of one block member can be releasably engaged with corresponding recess parts of the main body of the adjacent block member, the main body being provided with notches which can be releasably engaged with the connecting plate, the main body having a teeth portion which can be releasably engaged with a sprocket for driving the articular pole; and a take-up reel for storing the articular pole in a wound or curved state thereon.

Abstract: A deployable geodesic truss structure can be deployed from a stowed state to an erected state. The truss structure includes a series of bays, each bay having sets of battens connected by longitudinal cross members which give the bay its axial and torsional stiffness. The cross members are hinged at their mid point by a joint so that the cross members are foldable for deployment or collapsing. The bays are deployed and stabilized by actuator means connected between the mid point joints of the cross members. Hinged longerons may be provided to also connect the sets of battens and to collapse for stowing with the rest of the truss structure.

Abstract: An intrinsically hinged structural member is disclosed which can easily be bent, rolled or folded in one direction while exhibiting high resistance to bending, rolling or folding in the opposite direction. The general form of the structural member comprises a continuous side wall, a plurality of inner walls and a segmented outer wall. The inner walls confining cavities extending through the member. The slits in the segment outer wall define confronting faces which when forced together under stress exhibit a high resistance to any further bending or folding of the segment wall. Preferably, the confronting faces are complementary; the complementary faces which comprise male and female portions may periodically alternate from one side of the slit to the other to provide further resistance to torsional stress.

Abstract: An extendible structure includes at least three extendible longerons and a plurality of integrated radial spacers. Each spacer includes a plurality of legs integrally formed therewith to radially extend from the central part thereof. The distal end of each of the spacers is connected to a corresponding one of the extendible longerons. In the extended state of the extendible structure, at least three longerons are deployed in parallel with one another with space intervals among them in the lateral direction which intersect with the direction of extension of the longerons, and the spacers support the longerons with the horizontally spaced interval within a plane substantially perpendicular to the direction of extension of the longerons. In the collapsed condition of the extendible structure, each of the longerons is collapsed in a loop form, and the spacers are laid one upon another inside the loop formed by the longerons while the legs of the spacers are twisted.

Abstract: A plurality of beams or triangular plates members and beam members form a tetrahedral unit. These units are coupled at their common planes to adjacent facing units to form a foldable, extendible truss beam. Some of the beams are extendible or bendable. By extending or bending, each beam or plate member folds into a flat or bar shape.

Abstract: The invention provides a retractile polyarticulated mechanism comprising at least one elementary mechanism (4) formed of two endmost pieces (5, 6) one of which is a reference and, for connecting these endmost pieces (5, 6) together at least three legs (7,8,9) situated in separate planes and formed of two parts (10 and 11, or 12 and 13, or 14 and 15) each associated, on the one hand, with the other part forming the same leg by a spherical connection (16, 17 and 18) and, on the other hand, with an endmost piece (5, 6) different from the one with which this other part is associated by a rotoid connection (either 19 or 20, either 21 or 22, or finally 23 or 24).

Abstract: A multicomponent extendible structure that includes a plurality of elongated flexible members having interlocking members on their edges for enabling the elongated members to have their edges become interlocked as the multicomponent extendible structure is extended or deployed. The interlocking members provide compressive strength to the multicomponent extendible structure when it is deployed. A series of thin cable members are associated with each of the elongated flexible members to provide tension strength to the multicomponent deployed extendible structure. The multicomponent extended structure also has provisions for resisting twisting and it can be used to deploy or extend a variety of types of loads and yet be retracted into a compact package when it is not in use.

Abstract: An extensible mast is shown which is erected from a portable base having a plurality of tape reels mounted thereon. The tape reels are angularly oriented on the base with respect to a common, vertical axis, and each of the tape reels is adapted to receive a resilient metal tape having longitudinal edges for winding and unwinding the tape. A plurality of guide rollers on the base receive the respective longitudinal edges of the metal tapes and orient the tapes whereby the tapes are fed upwardly in planes parallel to the vertical axis and at an angle to each other to form a rigid structure. A geared winding mechanism, including a plurality of rotatable windings rotates about the vertical axis and wraps a wrap material about the rigid structure to reinforce the structure as it is being erected.