Abstract: A heavy cycle grating system incorporating a plurality of toothed support members to support a plurality of grate slats while securing them within grating assembly. This configuration allows the present grating system to accommodate higher volume of heavy use, such as found with vehicular applications. Further provided is a grating assembly configured for longer life and improved damage and wear-resistance while simultaneously reducing noise generated during use thereof.

Abstract: A hub for lighting at a grid intersection. The hub includes a light enclosure, light fixture, yoke, clip adapter, and beams. The enclosure includes connected walls each having a central offset portion with a connecting slot and multiple fixture slots. The yoke includes a middle section, two side sections, and two connector sections having protrusions. The yoke is attached to the enclosure by passing the connector sections through the connecting slots in opposite walls of the enclosure. Clips are inserted into the connecting slots that do not contain the yoke. The clips include arms extended therefrom and have protrusions. Beams with end adapters having holes are then connected to the enclosure by engaging the protrusions on the yoke and clips with the holes on the clip adapters. A light fixture can then be attached with fasteners passing through the fixture and slots in the fixture. Optionally a driver can be attached to the fixture.

Abstract: An interlocking elongate stackable spacer member for spacing structural framing members. The spacer is elongate having a lengthwise main portion and an offset portion, the offset portion defining a recess on a first side of the elongate body and a corresponding protrusion on a second side of the elongate body. The length of the protrusion corresponding to a desired spacing between adjacent trusses. The spacer can include a first end portion with a first connector and a second end portion having a cooperative second connector. The spacer is configured to interlock with another like spacer by inserting a first projection end portion of the first connector, into an aperture of the second connector, of the other of the spacer and the another spacer, such that the first projection end portion and the aperture of the second connector resist separation of the spacer and the another spacer along the lengthwise axis.

Abstract: A ceiling module and method of constructing the same, the ceiling module mountable on a suspended ceiling grid structure and including a plurality of elongate blade members having opposing faces, at least a part of each face of at least two blade members being substantially mutually opposed, at least one elongate cross member extending at least between at least two blade members such that the plurality of blade members are connected to form an arrangement; and at least one support member, releasably engageable with the suspended grid ceiling structure and associated with at least one of the blade members to support the plurality of blade members from the suspended ceiling grid structure.

Abstract: A component of an escalator, a moving walkway or an elevator includes a fastening device, which includes a spring element, a detent point for detenting the spring element and a support point for support of an attachment to be fastened. The spring element is pivotably arranged at the component, wherein in a stressed state the spring element is detented in the detent point and the attachment is pressed by the stressed spring element against the support point.

Abstract: The present disclosure relates to prefabricated building panels for use in structures, and walls external to structures, such as outdoor privacy walls and the like. More particularly, the present disclosure relates to a method and system for providing building panels that provide improved structural integrity, distribute loads, thermal performance, among other attributes using conventional framing members fit into precision cut grooves.

Abstract: A steel article for false ceilings or for supporting false ceilings and process for making the article is described. The article has the following combination of features: maximum tensile strength Rm greater than 500 N/mm2 and elongation from 0% to 15%.

Abstract: An end clip for joining runners of suspended ceilings by coupling with an identical clip, the clip being stamped from sheet metal stock with lead and trailing ends, a lateral projection and a projection receiving area behind the lead end, the clip being arranged such that when an identical clip oriented in the opposite direction of the clip and caused to laterally overlap the clip the projection of the clip is locked in the receiving area of the identical clip and, vice versa, at least one of the projection and projection receiving area having a rearward facing sheared edge forming an acute angle with the clip plane resulting from being sheared with tooling having a clearance between tooling substantially greater than 10% of the thickness of the sheet from which the clip is stamped.

Abstract: Structural panel unit (10) comprising a first plate (11) and continuous web members (13, 14) extending along intersecting directions so as to support the plate (11), the web members (13, 14) being each slotted (141, 131) partway through at their intersections so that they fit into one another, the web members comprising first web members (13) and second web members (14), wherein the first web members (13) are so disposed as to have slots (131) open towards the first plate (11) in which slots (131) fit the second web members (14), wherein the first web members (13) are united to the first plate (11) thereby interlocking the second web members (14), and wherein the second web members (14) are linked to the first plate (11) by no other means than by interlocking with the first members (13).

Abstract: Implementations of the present invention relate to devices, systems, and methods related to mounting decorative slats. In particular, the present invention facilitates accurate mounting and installation of a decorative multi-slat system, which can provide aesthetic enhancement for a particular space. Furthermore, the method of installing the decorative multi-slat system can allow an installer to reduce likelihood of errors and misalignments of the system, which can occur during the installation.

Abstract: An improved cellular building block including a middle beam and two legs. The cellular building block having the first leg coupled to the middle beam such that the leg is perpendicular to the middle beam and a second leg coupled to the middle beam such that the leg is perpendicular to the middle beam and spaced apart from the first leg, the first leg and the second leg having an inside edge and an outside edge. Having at least one barb located on the inside edge of the first leg and on the inside edge of the second leg and further configured to lock into a recess. The cellular building blocks connect in a two dimensional or three dimensional pattern and a produce a structured material that holds itself together and exhibits beneficial characteristics.

Abstract: The present invention provides for a bracket for use in a metal stud wall having internal bridging members for tying the metal studs and bridging members together. The bracket is an L shaped bracket having a leg for overlying the bridging member joined to an upright for overlying the metal stud. The outside corners of the leg and upright of the L shaped bracket are truncated such that the diagonal dimension across the L-shaped bracket is less than the width of the channel of the metal stud so that the bracket may be inserted within the channel of the metal stud and rotated to the proper position for attaching to the bridging member and metal stud.

Abstract: Structure (1) for mounting, on a building wall, at least one frame (50) consisting of a rectangular framework (51), comprising a carcass (2) made of at least two uprights (3) and at least two crossbars (4) assembled so as to form at least one rectangular underframe (15) adapted for receiving a frame (50), and means for fixing at least one frame on the carcass, each upright (3) having a central core (31) bordered by two side wings (32, 33) comprising recesses (38, 39) for receiving the crossbars (4). Each crossbar (4) has a central core (40) and side wings (41, 42) comprising recesses in line with the uprights (3) at the intersections between the crossbars (4) and the uprights (3) in such a way that the wings of the uprights (3) and the crossbars (4), extending on the inner periphery of the rectangular underframe (15), form a projecting border on which a frame (5) may be fitted. Wall provided with a structure of this type on which panel-holding frames are mounted.

Abstract: The present invention is directed to a bracket for use in a metal stud wall having internal bridging members for tying the metal studs and bridging members together. The bracket is an L shaped bracket having a leg for overlying the bridging member joined to an upright for overlying the metal stud. The outside corners of the leg and upright of the L shaped bracket are truncated so that the bracket may be inserted within the channel of a metal stud and rotated to the proper position for attaching to the bridging member and metal stud.

Abstract: A shutter having a unitary frame formed by four perimeter rails, each having a receptacle at each of its distal ends, with four connection members, each having structure inserted into and secured within one receptacle of each of two of the perimeter rails. Optionally, a latch pin is movable through a guide hole formed in one of the corner connection members. A further option is louvers extending through a center support.

Abstract: A stud spacer for use in a wall structure. The stud spacer includes a pair of opposed projections. The respective projections of the stud spacer interconnect with similar projections from adjacent stud spacers to form an interconnected series of stud spacers that extend through the studs that comprise the wall structure. When connected, each projection extends through an opening in an adjacent projection and a locking surface or locking tab associated with one projection seats in or against a stop or seat formed in the other projection.

Abstract: A support structure such as, for example, a door jamb and a window jamb. In one embodiment, the jamb is formed from a first stud that has a web and two first flanges and a second stud with a second web and second flanges. The first stud has at least one first hole through the first web and the second stud has at least one second hole through the second web. The first and second studs are oriented such that at least one first hole is aligned with at least one second hole and a stud engager is inserted through the aligned holes to retain the studs in abutting contact to form the jamb.

Abstract: A stud bridging/spacing member generally having at least three longitudinally spaced apart notches for receiving and engaging therein a web of a metal stud. At least one of the notches has opposing notch sides which are oriented such that when a portion of a web is received therein, one of the notch sides contacts the web at a first portion of the web and the other notch side contacts the web at a second portion of the web such that the first portion of the web and the second portion of the web are not located on a common longitudinal axis.

Abstract: A metal stud wall and method of assembling the same are characterized by a stud bridging/spacing member generally having at least three longitudinally spaced apart notches for receiving and engaging therein a web of a metal stud. The notches extend at an incline to the longitudinal axis of the elongate member. In the assembly of a metal stud wall having a row of metal studs each having at least two flanges interconnected by a web, the stud bridging/spacing member is inserted through aligned openings in the webs of three or more studs and the webs are engaged in the notches to position and hold the metal studs at a prescribed spacing. Successive bridging/spacing members may be inserted through further studs and overlapped with the preceding bridging/spacing member, and engaging a common stud, to position and hold the studs at the prescribed spacing.

Abstract: A first ceiling panel supporting stringer 1 has an insertion hole 10 formed through a main plate portion 4 thereof, and a second ceiling panel supporting stringer has a base plate portion 21 extending from an end thereof and having a forward end engageable with one side of the main plate portion 4 of the first ceiling panel supporting stringer 1, and a connecting projection 22 extending from the forward end of the base plate portion 21. The connecting projection 22 has a U-shaped rise 24, which is provided with a reinforcing rib 31 for improved strength. The first and second ceiling panel supporting stringers can be unseparably connected by pressingly inserting the connecting projection 22 of the second ceiling panel supporting stringer 1 through the insertion hole 10 of the first ceiling panel supporting stringer 1 without special skills.

Abstract: A stud spacer for connecting and extending between studs within a stud wall structure. The stud spacer includes an elongated member having a series of curved shaped notches formed in the member with each notch being adapted to receive a portion of a stud such that the stud spacer effectively connects to and extends between respective studs.

Abstract: A vertical intersecting lightweight steel frame includes several main frames and side frames, which are connected with each other vertically. A first oblique fold is formed on two sides of the main frame and a protrusion is on the bottom of the side frame. The angle of the first oblique fold on both sides of the indention of the main frame is less than 45 degrees. A second oblique fold above the first oblique fold has an angle of 45 degrees. The angle of the protrusion of the side frame is also 45 degrees. The whole structure is stronger and easier to assemble. A darkened area of the vertical connection between the main frame and side frame is kept hidden.

Abstract: A modular deck tile comprises a plurality of slats which are joined together by at least two flexible tubes extending through the thickness of each of the slats. So as to preserve the spacing of the slats, and to keep them in place, the tubes may be laterally deformed in the region between each pair of slats so as to cause a greater cross wise dimension than the diameter of the passage through which the tubes extend. Alternatively, the slats may be joined one to another by poppet connectors.

Abstract: A grid tee of the double web type in which the elements of the web are integrally stitched together to prevent their separation. The stitches are created in an inexpensive rolling process that does not require control of the position of the stitches relative to the ends or other parts of the tee. According to the invention, after the stitches are formed and locked, they are flattened back into the plane of the web to a limited degree where they do not substantially increase the thickness of the web so that they do not interfere with subsequent manufacturing steps or with field assembly.

Abstract: In a panel ceiling, a grid that supports panels has main beams and cross beams. In assembly, the main beams are directly attached to an overhead structure and the cross beams and panels are assembled onto the main beams. Stepped slots in the main beams enable the cross beams to be locked to the main beams to keep the cross beams and panels aligned.

Abstract: A metal stud wall and method of assembling the same are characterized by a stud bridging/spacing member generally having at least three longitudinally spaced apart notches for receiving and engaging therein a web of a metal stud. The notches extend at an incline to the longitudinal axis of the elongate member. In the assembly of a metal stud wall having a row of metal studs each having at least two flanges interconnected by a web, the stud bridging/spacing member is inserted through aligned openings in the webs of three or more studs and the webs are engaged in the notches to position and hold the metal studs at a prescribed spacing. Successive bridging/spacing members may be inserted through further studs and overlapped with the preceding bridging/spacing member, and engaging a common stud, to position and hold the studs at the prescribed spacing.

Abstract: A device capable of being attached to a roof as part of a snowguard system to prevent snow or ice from falling off the roof. The snowguard system includes a plurality of mounting brackets each having a bracket portion with at least one bore defining at least one cutout region therethrough. This cutout region has a first circumferential shape. At least one pipe is slidably inserted through one of the bores in each of the bracket portions. Each pipe has a circumferential shape substantially similar to that of each cutout region to thereby prevent rotation of the pipe with respect to the bracket. At least one flag is provided for attachment to the pipe. Each flag has an interior which is substantially geometrically similar to at least a portion of the circumferential shape of the pipe, thereby allowing the interior portion of the flag to lockingly engage the exterior of one of the pipes such that the flag does not rotate with respect to the pipe to which it is attached.

Abstract: A lattice girder supporting frame for tunnel lining includes upper and lower boom members arranged parallel to each other to form a triangle. Truss braces spatially connect the upper and lower boom members to each other, wherein each of the truss braces has straight brace parts angled relative to each other, and each of the straight brace parts is connected to each other at one end via a straight bridge piece. The truss braces are arranged in a symmetrical plane extending laterally from the upper boom member to an axis of the lower boom members. Cross ties extend at right angles relative to the lower boom members, for connecting the lower boom members to each other, wherein the truss braces abut the lower boom members without bending and are welded to the lower boom members.

Abstract: A lattice girder supporting frame for mine and tunnel lining has a plurality of boom members arranged in parallel relative to each other, forming a triangle. The boom members are spatially connected to each other by straight braces arranged along the edges of a pyramid so as to form a truss brace. The braces are each welded to the boom members at the contact faces between a straight brace part and an upper boom and a straight brace part and a lower boom. The lower booms are connected to each other via cross-ties arranged at right angle relative to such booms and the cross-ties form two sides of the pyramid base surface wherein four comer points of the base are defined by the truss braces at the contact points between the lower booms and braces.

Abstract: The invention relates to a shuttering element for separating a concrete section into concrete subsections. The shuttering element is of strip-like form and is adapted widthwise to the thickness of the concrete section. It comprises at least a strip-like shuttering board which is formed from a thin-walled, sheet-like material, with the result that, once the concrete section has been cast, the shuttering board can remain between the cast concrete subsections. The shuttering board preferably has recesses through which reinforcement struts can engage, with the result that the shuttering element according to the invention can be inserted even when reinforcement struts of a reinforcement are required to cross the shuttering element.

Abstract: A combination grille for window, which includes four hollow side frame bars arranged at four sides, and crossed hollow transverse frame bars and hollow longitudinal frame bars arranged within the side frame bars, and a plurality of sliding cover plates respectively covered on the side frame bars and the transverse frame bars, wherein the side frame bars and the transverse frame bars each have a longitudinal opening at one side, two sliding grooves longitudinally extended along two opposite sides of the longitudinal opening; the side frame bars each have a longitudinal series of coupling holes at one side adjacent to the respective longitudinal opening; the transverse frame bars each have a plurality of longitudinally spaced transverse through holes across the respective longitudinal opening for the passing of the longitudinal frame bars; the sliding cover plates are respectively covered on the longitudinal opening at each of the transverse frame bars and the side frame bars, each having two coupling flanges l

Abstract: A lattice girder generally including a top rail, a bottom rail, vertical end posts and slanted crossbeams, wherein all of the members consist of uniform hollow sections that may be fitted into one another and thereby rigidly interconnected. The girder rail consists of two half-sections (18,19) internally provided with longitudinal flanges (20, 21) having transverse serrations so that the two half-sections may be permanently secured to one another by pressing them together with the serrations in mutual engagement. The end of a slanted crossbeam (24) having notches (at 25 and 26) is inserted into openings (22,23) in the half-sections to lock and engage the rail. Weldless lattice girders may thus be produced, in particular for forming a walkway guardrail.

Abstract: A substantially rectangular reinforcement assembly for concrete castings, having a longitudinal axis and a transverse axis. The assembly comprises a frame, a first set of longitudinal runners, a second set of transverse runners, and a third set of transverse runners. Each individual runner has two short ends, and each short end has a frame holding means. The runners are arranged in a hatch pattern, where the longitudinal runners are arranged substantially perpendicular to the transverse runners. The frame comprises a first leg member, a second leg member, and a shoulder member. The first leg member has a plurality of through holes and the second leg member has a corresponding number of through holes, which are substantially concentric with the corresponding through holes of the first leg member.

Abstract: A hook type assembly that interlocks a pair of intersecting cross-beams and a main beam in a grid for a suspended ceiling. A gapped ridge in a clip on each cross-beam engages the other gapped ridge in a vertical movement that is part of a hooking action while the assembly is formed. The assembly can be optionally made to provide for expansion during a tire.

Abstract: A locking connection used to join the cross runners and main runners of a suspended grid ceiling system. The main runners are provided with periodic openings through which the cross runner ends are inserted and thereby locked together. Each cross tee end connector contains a resilient finger which engages the main runner upon insertion. Further, each connector has apertures and raised detents which will mate with those of a like opposing cross tee end connector when both are inserted through the same main runner opening. A locked grid intersection can be disengaged by depressing the resilient finger holding the main runner, rotating the main runner over the cross runner end connector, and pushing the cross tee end vertically free.

Abstract: A metal stud wall and method of assembling the same are characterized by stud spacer member comprising an elongate bar-like member and at least three equal spaced notches disposed along the elongate member for receiving and engaging therein a web of a metal stud. In the assembly of a metal stud wall comprising a row of metal studs each having at least two flanges interconnected by a web, the stud spacer member is inserted through aligned openings in the webs of three or more studs and the webs are engaged in the notches to position and hold the metal studs at a prescribed spacing. Successive spacer members may be inserted through further studs and overlapped with the preceding spacer member to position and hold the studs at the prescribed spacing.

Abstract: A frame material for a wall of a building, including a metal beam, and a tubular rectangular metal stud having opposite sides each provided with a window through which the beam is capable of being inserted and in which the beam is received such that the lateral movement is prevented. One of the windows has a stopper member which is displaceable between close and open positions and which extends from one side to the other side of the window. The stopper member in the closed state prevents the beam received in the windows to move vertically.

Abstract: An entry grid includes a plurality of spaced, side-by-side, grid sections each having a tread rail and a depending support leg with sections interlocked by a locking bar extending transversely through respective locking holes in the support legs. The support legs include locking teeth engaged by complementally configured element teeth of corresponding locking elements extending radially from the locking bar shaft.

Abstract: A grid framework for a suspended ceiling wherein reinforced cross members are allowed to expand; without collapsing or buckling, during a fire. Clips at the end of the members create barriers that are successfully overcome, in stages, to relieve any excess longitudinal compressive forces capable of being built up by the reinforced members.

Abstract: A masonry construction aid that enables novice and professional masons to easily construct a masonry structure such as a sidewalk, patio, driveway or vertical wall. The aid allows its user to insert masonry into a pre-determined, pre-formed, soluble pattern that contains within it a bonding material. After applying a catalyst such as water to the pattern, the pattern will disintegrate, the bonding agent will activate and bond the masonry together and harden into a permanent structure. This will result in a masonry structure that does not require any special skills to construct. The user will not be required to prepare or apply mortar, or manually align the masonry.

Abstract: A metal barrier including a rectangular metal frame having a plurality of plug holes on the inside on two opposite vertical sides and two opposite horizontal sides thereof; a plurality of transverse metal tubes mounted within the rectangular metal frame and having respective both ends respectively and fitted into the plug holes on the opposite vertical sides of the rectangular metal frame, each transverse metal tube having a row of through holes; and a plurality of longitudinal metal tubes intersected with the transverse metal tubes and mounted within the rectangular metal frame, the longitudinal metal tubes being respectively inserted through the through holes of the transverse metal tubes and having respective both ends respectively fitted into the plug holes on the opposite horizontal sides of the rectangular metal frame.

Abstract: A cruciform joint of glazing bars comprising a glazing bar extending between and perpendicular to an aligned pair of glazing bars. Each glazing bar has a central load bearing portion (16) which has a solid snapfit formation (22) at one end, interconnected to a solid end portion (23) by a hollow mid-portion (21). A base portion is interlocked with the solid end portion (23) and a clamping section is snap-fitted onto the snap-fit formation (22) so that a respective pane of glazing material can be clamped therebetween. The aligned pair of glazing bars are connected by a key (19) which is placed through a keyhole (18) in the intervening glazing bar and which extends into the hollow mid-portions (21) of each of the aligned pair. The keyhole (18) is formed solely through the hollow mid-portion (21) of the glazing bar, and the key (19) is inserted through the aperture (18) and then rotated and snap-fitted into a locked setting.

Abstract: A metal stud wall and method of assembling the same are characterized by stud spacer member comprising an elongate bar-like member and at least three equal spaced notches disposed along the elongate member for receiving and engaging therein a web of a metal stud. In the assembly of a metal stud wall comprising a row of metal studs each having at least two flanges interconnected by a web, the stud spacer member is inserted through aligned openings in the webs of three or more studs and the webs are engaged in the notches to position and hold the metal studs at a prescribed spacing. Successive spacer members may be inserted through further studs and overlapped with the preceding spacer member to position and hold the studs at the prescribed spacing.

Abstract: The subject of this invention is a security window bar system containing three types of elements. The first type comprises a plurality of vertical bars, the second type comprises at least two horizontal metal plates, and the third a plurality of right angular, generally L-shaped brackets or fasteners. The vertical bars are held in place by the horizontal crossbars which have therethrough spaced openings which the vertical bars extend. Opposite ends of the horizontal crossbars are fastened to opposite sides of the window frame by the L-shaped fasteners, each of which has one leg fastened to an adjacent end of a crossbar, and the opposite leg fastened to the window framework by a one-way screw. The result is a simple, inexpensive, and easy to install window bar grid system that prevents unwanted intruders from entering the structure.

Abstract: A metal frame insulated building system using metal studs and sole and cap blocking tracks of "C" cross-section anchored to a foundation and to each other. The studs and cap blocking tracks physically interlocked in addition to being mutually secured by fasteners. Vertical stacks or columns of foamed cement blocks are placed between the studs and grooves on one or both sides of the blocks receive stud flanges to interlock the studs and blocks. The bottom and top blocks of a stack similarly interlock via grooves with the blocking track flanges. The blocks protrude beyond the studs on the structure's exterior, substantially covering the stud and blocking track flanges and attenuating thermal conductivity as well as providing an exterior surface for stucco or other finish.

Abstract: A grid assembly, and method for use in manufacturing a grid reinforced concrete deck, including a plurality of longitudinally extending main beams in parallel spaced relation, each of the main beams having a plurality of longitudinally spaced slots therein and a central flange thereon, a plurality of cross bars adapted to be inserted through the aligned slots and rotated into an upright position, a form pan extending between two adjacent main beams and having a first and a second side portion adapted to rest on the central flange of the two adjacent main beams, respectively, wherein the form pan includes at least a first ridge extending upwardly thereon, the first ridge having a height which enables a lower edge of the cross bars to come into contact therewith when in the upright position, wherein the contact causes a downward force on the first ridge which mechanically locks the form pan between the cross bars and the flange on the adjacent main beams.

Abstract: A generally channel sectioned wall stud 7 which has been cold roll-formed from a sheet metal strip comprises a web 8 and two flanges 9. The web 8 has a substantial central strip that is planar. A nogging clearance hole 10, is provided in the central strip of the web 8 at each point where a nogging 11 is to be affixed thereto. The nogging 11 may be roll-formed from material the same as or similar to that of the stud 7 and is also generally channel sectioned, comprising a web 12, with a flat ended central rib 13 formed therein and flanges 14. The web 12 is pierced by clearance slots 15 arranged in two rows extending longitudinally of the nogging 11. The individual slots 15 are regularly spaced apart along the rows. The nogging clearance hole 10 is shaped to suit the nogging 11. To that end it is partly defined by two tabs 16 projecting from the web 8 and lying in the plane of its central strip 13.

Abstract: An exodermic deck for structural floors including bridge floors, road beds, pedestrian walkways, or the like, comprises a composite structure of a grid component and a top component. The grid component is preferably made of steel and includes a plurality of main bearing bars and a plurality of distribution bars oriented perpendicular to the main bearing bars. The top component is preferably made from reinforced concrete. The upper portions of either the main bearing bars or the distribution bars are embedded in the reinforced concrete component permitting horizontal shear transfer and creating a composite deck structure which maximizes the use of tensile strength of steel and the compressive strength of concrete. The top sections of the embedded bars have gripping surfaces for effecting mechanical locks between the grid component and the concrete component and increasing the horizontal shear transfer therebetween.

Abstract: A method for joining tubular members at right angles for use in the construction of a rail and pole metal fence or grating, in which the poles are inserted through pre-punched multi-sided clearance holes in the rails and are secured in the clearance holes by a coupling bar that engages slots in the slides of the poles as it is inserted longitudinally inside the rail.

Abstract: Known lattice girders consist of two structural chord members joined to each other by a so-called lattice snake welded at its points of inversion to said structural chord members. To circumvent this welding, structural chord members 11 are used which comprise mutually opposite longitudinal slots 18 and thereunder a longitudinal chamber 19. The lattice-snake of the prior art is replaced by individual struts 13 evincing an I section and matching the structural chord members 11. The longitudinal ends of the struts 13 are cut at acute angles and parallel to each other. The two flanges 16 of the struts 13 comprise slots 21 at both ends and parallel to the longitudinal ends of the struts 13. Thereby the struts 13 can be snugly inserted into the longitudinal slots 18 and the chamber 19 of the structural chord members 11 wherein they butt each other.