MXPA00003374A - Structural shape for use in frame construction - Google Patents

Abstract

A structural section (10) for use in frame construction where the section includes a horizontal segment (11) and a pair of spaced apart legs (12a, 12b). Each leg has a first end portion (13) attached to the horizontal segment, a second end portion (14) opposite the horizontal segment, and a flange (16) that extends inward from the second end portion toward the centerline of the stuctural section. Each leg further includes a longitudinal surface (15) located between the first end portion and the second end portion. The longitudinal surface is positioned inboard of the flange so that the distance between opposed flanges that extend along each leg of the structural section is greater than the distance between opposed longitudinal surfaces that extend along each leg of the structural section.

Description

INTERMEDIATE CONSTRUCTION Field of the Invention This invention relates to trusses or roof frames used in the construction industry for the construction of light commercial and residential buildings. More particularly, this invention is directed to the rope sections that are used to assemble the trusses or roof frames used in the construction of light weight steel trusses.

Background of the Invention Wood is the predominant framing material used in light commercial and residential construction in the United States. However, builders, annoyed by volatile and rising wood prices and poor quality as wood supply storage, continue to look for alternatives. Recent studies have identified steel as an alternative framing material Rfsf.033172 for wood. Several attempts have been made in the past to introduce non-wood framework materials, including advanced materials such as fiber-reinforced plastic, as well as lightweight steel components such as doors, windows, decking boards, lining and trusses. However, history shows that wherever a new material becomes available to the construction industry, it is adopted cautiously, initially in small scale applications. Therefore, many of the most recent substitute wood materials are not yet in wide use within the construction industry. For example, in the case of residential steel framework, acceptance has been slow because many builders have tried to assemble a lightweight steel framework using traditional wood-building techniques. Such methods of wood construction involve labor costs when they are applied to the construction of the steel framework, and this makes the steel framework uncompetitive with the construction of the conventional wood framework. Consequently, the construction of steel trusses has gained only a small space in the market of house construction when compared to timber-framed houses. The construction of steel trusses tends to be concentrated mainly in areas where houses need to meet stricter structural demands to withstand natural phenomena such as earthquakes, winds with high hurricane strength, and pest problems such as termites. However, with the adoption of new construction techniques that include, for example, the prefabricated steel truss panels supplied assembled to the construction site, and with the availability of new bolt-on guns and fasteners that facilitate and improve connections From steel framing, residential steel framing is gaining popularity within the construction industry. In particular, residential roof framing is an area that currently offers improved opportunities to use substitute wood construction materials. Manufacturers have introduced an array of different roof trusses that are not made of wood, ranging from panels for the steel roof, rafters and straps, to trusses or frames for lightweight steel lattice ceilings. ^ prefabricated, designed to carry heavy loads ^ long fi bers. The state of the art for the designs of trusses or frameworks for the different roofs of the wood is dynamic. "Numerous improvements in the design of the trusses or frames for the different steel roofs have taken place over a relatively short period of time, with many of these improvements directed to the shape of the structural sections used for the rope elements or upper and lower cord of the truss or roof frame. NeverthelessIt has been found that the rope or cord sections of the roof trusses or frames of the past present a great deal of problems for the manufacturer of roof trusses or frames as well as for home builders. For example, in Figures 6 and 13 of U.S. Patent No. 4,435,940 to Davenport et al., Figures 2 and 5 of U.S. Pat. No. 4,982,545 to Stromback, and in Figures 3 and 6 of U.S. Pat. No. 4,986,051 to Meyer, sections of the rope or cord of trusses or frames for the roof are shown comprising projections extending outwardly. Such outwardly extending projections provide rigidity and improve the strength of the strings of the roof truss. However, protrusions extending outward prevent the ropes from resting flat during shipping and handling, and make the fabrication of trusses or roof frames difficult. Additionally, protrusions that extend outward expose sharp metal edges, and workers handling such sections of cord or cord must exercise extreme caution to avoid serious cuts, lacerations and other damage. U.S. Patent No. 5,463,837 to Dry, teaches the formation of an external hemmed edge along both legs of a rope or truss cord or roof frame. This could tend to protect workers from injuries. The hemmed edge along the radius eliminates the sharp edges associated with the outwardly extending projections taught in the three previous patents. However, the tests show that such hemmed edges greatly reduce the properties of the rope section of the truss or roof framework to undesirable levels when compared to the outwardly extending projections cited above.

Other light-frame sections show the provision of a projection extending inward that maintains the good properties of the section. For example, Figures 1, 3, 5, 7 and 9 of the Patent of the United States of America No. 5,157,883 of Meyer, shows the projections that extend inwards. The Meyer 883 patent is directed to vertical studs used in the lightweight steel framework. Another example of inwardly extending projections, in a truss or roof frame, is shown in Figures 4 and 7 of U.S. Pat. No. 4,982,545 issued to Strombach. Although such inwardly extending projection sections may tend to reduce worker damage, maintain good section properties, and allow the sections to rest flat during fabrication of the truss or roof frame, they create a new set of problems for the manufacturer of roof trusses or frames. A truss or frame for the typical roof comprises a plurality of interlocking elements extending between the elements of the rope or upper and lower cord of the truss or roof frame. Each interlocking element is inserted between the doors of the rope or upper cord and between the legs of the lower element, and each locking element for the roof is fastened to the elements of the cord or cord using screws of $ Metallic perforators 5 extending to tra | P from the legs of the rope or cord and towards the interlocking elements or braces. In cases where the rope or cord sections of the truss or roof frame include projections extending inward, prior to the present In the invention, it has been impossible to use self-drilling screws or other simple fasteners to make the interlocking connections with the rope or cord of the roof truss or frame, necessary. As clearly shown in Meyer's patent, the outgoing that extend inward create a large gap, or space, between the legs of the cord or cord and the inserted interlocking element. Special connection physical elements must be used to secure the interlocking elements of the truss or frame for the roof to the elements of the rope or cord of the truss or framework for the upper and lower roof, as illustrated in Figure 9 of Meyer, and such physical elements are economical to produce and to use with respect to the consumption of time.

In an attempt to overcome the foregoing problems, a manufacturer of roof trusses or frames is fabricating and selling a section of roofing rope that has inside the frames formed along the upper edge of both legs of the roof. the rope or cord. The hems are formed with a narrow radius to be coplanar with a corresponding leg surface that engages the interlocking elements of the truss or roof frame that are inserted between the legs of the cord or cord section. This roof truss design allows the truss cords to rest flat during fabrication of the truss or roof frame, eliminating sharp metal sheet edges along the legs of the truss. the rope or cord, and makes it possible for manufacturers to make interlocking connections with the roof truss or frame using self-piercing metal foil screws. However, as stated above for the external hems, the tests show that the edges with hems produce very undesirable section properties in the cords of trusses or roof frames. Additionally, in the cases where the internal hems become deformed, already during the training operations or during boarding and handling, the deformed hems interfere with the insertion of the interlocking elements d # the truss or frame for the roof inside the sections of the rope or cord during the manufacture of the truss or framework for the roof. The legs of the rope or cord must be placed apart to provide a spacing between the deformed hems, and this produces a gap between the interlocking element of the truss or frame for the roof and leg of the rope or cord that causes the self-drilling screws not to settle properly when making the connection connections with the roof truss or frame. Such defective connections are rejected if they are discovered during the inspection of product quality, and if they are not detected, they may fail prematurely under the actual load conditions.

Brief Description of the Invention Accordingly, it is a first object of the present invention to provide a structural form comprising a horizontal segment extending between the legs spaced away, the structural shape that does not - aSÉ has sharp edges -exposed along its length. Another object of the present invention is to provide a structural shape that does not have 5 outward projections that prevent the structural form from resting flat along any of its outer surfaces. It is another object of the present invention to provide a locking connection with the roof truss or frame where the mechanical fasteners do not extend outside the periphery of. the structural form so that the truss or frame for the assembled ceiling can rest flat along any of its external surfaces. It is another object of the present invention to provide a structural shape having an inwardly pointing projection extending along each leg spaced apart to improve the properties of the section of the structural form. It is still another object of the present invention to provide a structural shape wherein the projections pointing inward provide a spacing for inserting interlocking elements of the truss or roof frame between the legs spaced apart from the structural section during assembly . > z, '?? S = Hffliá As-. The invention provides a structural feature wherein the projections pointing inward, extending along the legs of the dryer facilitate the connection of the interlocking elements of the truss or frame for the roof inserted without the special physical connection elements. For the satisfaction of the foregoing objects and advantages, the present invention provides a structural section comprising a first leg and a second leg, which is spaced from the first leg and connected thereto by a horizontal segment, the first leg and the leg. Second leg comprise each one: i) a first end portion fixed to the horizontal segment, ii) a second end portion opposite the first end portion and including a projection extending in an inward direction from the second end portion, and iii) a longitudinal securing surface extending along the leg between the first a and the end portion, characterized by longitudinal securing in and is positioned within the projection so that a distance between the projections of the first leg and the second leg is greater than a distance between the longitudinal securing surface extending along the first leg and the second leg. GB 2 222 188 A discloses a structural section, which from its external appearance resembles the structural section according to the present invention. However, the prior art device has its securing surfaces on the surfaces directed out of the legs and consequently serves a completely different purpose.

Brief Description of the Drawings Figure 1 is an end view of the preferred structural form of the present invention.

The Fi i4 d 1%. is a fragmentary view of Figure 1 showing a deformed protrusion pointing inward from one of the legs. Figure 2 < • # an elevation view that shows an exemplary roof truss or frame fabricated using the structural form of Figure 1 as the truss cords or frame for the upper and lower roof. Figure 3 is a partial end view of the present invention showing a modality of the alternative projection. Figure 4 is a partial end view of the present invention showing a second embodiment of the alternative projection. Figure 5 is a partial end view of the present invention showing a third embodiment of the alternative projection. Figure 6 is an end view of a rope or cord of the truss or roof frame of the prior art having internal hemmed legs. Figure 7 is an end view similar to Figure 6 showing the hems of the deformed inner leg. Figure 8 is an enlarged view of Figure 25 7.

A *? ** > *? til§kmm - -? * "-" * - ** Figure 9 is a view of the rope or cord of the truss or ma? n for the roof in Figure 7 showing a locking element of the forced fence between the hems of the pic &st3ß8 &deformed Figure 10 is an enlarged view of the Figure 9 showing a connecting connection with the rope or cord of the truss or frame for the roof.

Detailed Description of the Preferred Modality Referring to the extreme view labeled as the Prior Art in Figure 6, the Figure illustrates a rope 1 of the elongated roof truss. The rope 1 of the roof truss includes a horizontal segment 2 and a pair of legs 3a and 3b spaced apart, including hemmed edges 4a and 4b formed along the length of the upper end of each leg. The legs spaced apart further include inner surfaces 5a and 5b which are placed within the plane of the legs 3a and 3b for coupling the interlocking elements 7 of the truss or roof framework that are inserted between the legs 3a and 3b to manufacture a Truss or frame for the roof. The hems 4a and 4b include internal surfaces 6a and 6b that are coplanar with the inner surfaces 5a and 5b. The distance "DI" between the surfaces 5a and 5b of the leg corresponds to the external width "Wl" of the interlocking elements 7 of the truss or roof framework that are inserted inside the sections 1 of the cord of the truss or frame for the roof during the manufacture of trusses or frames for the roof. Because the internal hem surfaces 6a and 6b are coplanar with the surfaces 5a and 5b, the interlocking elements 7 of the truss or roof frame could slip between the hems with very little extra effort when they are inserted. between the legs of the truss rope or frame for the roof. This coplanar alignment could allow manufacturers to use self-piercing metal sheeting screws, rivets, or mechanical fasteners to connect the interlocking elements of the roof truss to the legs 3a and 3b of the rope section during fabrication. of a truss or frame for the roof. However, small radius hems can be problematic during cylinder formation and they are often shaped in a deformed manner as shown in Figures 7 and 8 of the truss rope or roof frame of the prior art . The Figures of the drawings show that the deformed hems 8a and 8b can extend inward, beyond the "P" plane of the internal surfaces 5a and 5b. This is because the forming operation causes the metal to flow inward toward the center of the section when the hem is formed, and any excess metal or deformity is pushed towards the center line of the rolled section. The hemmed edges can also be damaged and deformed during shipping and handling of a finished section product. In such circumstances, where the hemmed edges are either erroneously or deformed, the inner surfaces 9a and 9b are no longer coplanar with the "P" plane of the inner surfaces 5a and 5b. This creates a problem for inserting the interlocking elements 7 of the roof truss or frame. It becomes very difficult to insert the interlocking elements of the roof truss or frame into the truss rope or ceiling frame without levering and bending the legs of the rope away as shown by the arrows in the direction "A" in Figure 7. Such levering and pulling can create a varied problem classification during the fabrication of the truss or roof frame.

For this reason, the prefabricated trusses or roof frames are assembled on large distribution tables that hold lengths of the truss rope or roof framework of 3,048 m (10 ft) 5 and larger. It may be difficult to lever up and bend the legs of the rope away from each other to insert the interlocking elements of the truss or roof frame between the hems with the wrong shape, or damaged, or deformed. Additionally, when interlocking elements 7 of the truss or roof framework are finally forced between such hems and seated in their respective positions along the length of the cord, as shown in Figure 9, the misalignment between the hemmed edges and the surfaces 5a and 5b of the leg create a "Gl" gap in the interlocking connection with the rope of the truss or frame for the roof. As a result of this gap, when self-piercing metal foil screws 20, or other suitable fasteners are driven through of the elements for making the interlocking connection 21 with the rope of the truss or roof frame, it is impossible to stretch the two pieces together, as shown in the enlarged view of a connection in Figure 10, without distorting the section of the rope. 25 Such poor connections are structurally unsound.

^ On the one hand, for example, if the fasteners fail to close the gap in the connection of the latch with the truss rope * "or frame for the roof, the" open "connection can induce bending forces in the On the other hand, if the fastener is rotated until the gap in the interlocking connection with the truss rope or roof frame is closed, the additional force required to distort the fastener section will cause the fastener to tilt. The rope may overload the fastener and weaken the connection In such cases, the overloaded fasteners may either break, or the fasteners may tear or tear through the metal foil connections and cause a structural failure Referring to Figure 1 of the drawings, the preferred embodiment of the present invention overcomes the aforementioned problems by providing a structural section 10 comprising a horizontal segment 11 and a prime ra leg 12a spaced away from a second leg 12b. Each leg includes a first end or lower portion 13 fixed to the horizontal segment 11, a second end or top portion 14, and a longitudinal securing surface 15 located between the lower end portion 13 and the upper end portion 14 of each leg 12a and 12b respective. The longitudinal securing surfaces 15 are positioned within their respective first and second end portions 13 and 14, and the surfaces 15 are spaced at a distance "D2" equal to the external dimension "2" of the interlocking elements of the truss. or roof frame or braces 19 which are inserted between the legs spaced apart during mounting operations. This allows the longitudinal surfaces 15 spaced apart to engage the interlocking elements of the roof truss inserted between the legs 12a and 12b of the structural section. Each end portion 14 of the structural section 10 comprises a longitudinally extending projection 16 or the points within the respective legs 12a and 12b towards the center line of the structural section 10. Each projection includes a flat or smooth segment 17 communicating with its respective leg 12a and 12b and ends in a leg 18 pointing downwards, perpendicular to the flat segment 17. The projections 16 extend inwardly from the legs 12a and 12b to a position that places the legs 18 pointing downwards out of their respective longitudinal surfaces 15. This provides a "G2" gap between the lowAtus surfaces 15 their corresponding projections 1 As clearly illustrated in Figure 1, the distance "D3" spaced apart from the opposite projections 16 is greater than the distance "D2" spaced far between the opposing longitudinal fastening surfaces 15. This difference in distances provides the gap "G2" which makes it possible for the structural section 10 to overcome many of the manufacturing and securing problems described above in the prior art shown in Figures 6-10. For example, the Figure shows a deformed projection 16b extending along a portion of the leg 12b of the preferred embodiment. However, because the predetermined gap "G2" provides a clear space, the deformed projection 16b does not extend beyond the plane "Pl" of the longitudinal surface 15. The predetermined gap "G2" extends along the length of the length of the structural section 10 in the event that a projection is deformed in any part along the length of the section. Therefore, the gap "G2" provides a spacing for the proper alignment of the interlocking element of the truss or roof frame when the projections 16 of the rope element become deformed, and the gap is also provided for the proper fastening of fasteners in the interlocking connections with the rope of the truss or frame for the roof 21, along the total length of the structural section. Referring once again to Figure 1A, the longitudinal surfaces 15 are spaced within the lower and upper end portions 13 and 14 a distance 20a that is greater than the thickness of the head 20b of the fasteners 20 used to make the connection of the interlocking with the rope of the truss or framework for the roof. This arrangement lowers the fasteners below the surface of legs 12a and 12b of the section, making it possible for the truss or frame for the assembled roof to rest flat during shipping and handling, and protects the fasteners from damage. It should be understood, however, that although the preferred embodiment shows the projections 16 comprising a flat segment 17 terminating in an end leg 18 pointing downward, other shapes of the projection pointing inward, equivalent, can be used without depart from the scope of this invention. For example, referring to Figure 3, an equivalent structural section 10 is shown, including the projections 16 spaced apart that are similar to the satellites of the preferred embodiment. In this case, without being straight, the flat or flat portion 17 ends in a leg 22 pointing downwards which is inclined towards the central 3-a of the structural section in a position that will provide the necessary gap "G2" for the alignment and appropriate support in the event that a projection is deformed. Similarly, a second alternative embodiment is shown in Figure 4, which comprises a structural section 10 having the spaced projections 16 similar to the projections of the preferred embodiment. In this second case the flat portions 17 terminate in downward pointing legs 23 which are inclined outwardly away from the centerline of the structural section in a position providing the necessary gap "G2" for proper alignment and fastening in the case that a protrusion is deformed. Similarly, a third equivalent embodiment, shown in Figure 5, comprises a section 10 having spaced projections 16 comparable to the projections of the preferred embodiment. In this last example the flat portions 17 end in the curvilinear legs 24 which are positioned to provide the "G2" gap necessary for the alignment and clamping if a projection is deformed. Any of the arrangements of the projection shown in Figure dj Figures 3-5, or any other arrangement of the equivalent projection that provides the necessary "G2" gap, is suitable for use as a section of the rope in the assembly of the trusses or frames for the roof "T" exemplary shown in Figure 2. The trusses or frames for the roof "T" comprise a section of the upper and lower cord 10a and 10b respectively. The interlocking elements of the roof truss or braces 19 extend between the sections of the upper and lower chord and the interlocking elements are attached to the chords in the connections 21 as described above. However, it should be understood that the structural form of the present invention is not intended to be limited to use in a roof truss or frame. For example, referring to Figure 11, the structural section of the present invention is shown being used as the upper and lower strings 25a and 25b in a truss or roof frame. Similarly, in Figure 12, the structural section is shown used as a lower and upper chord 26a and 26b over an opening in the window. Figure 13 shows the structural section adapted for use as a guide or tread band 27 for the truss and a stud 28 for residential or light commercial fabric. As described so far, the inward pointing projections 16 of the present invention, in combination with the "G2" recess, overcome many of the problems of the previous structural sections used in the residential framework. For example, to ensure proper alignment and good interlocking connections with the truss rope or roof frame, designers of the past have provided tight hem ends as shown in Figure 6. Referring to "Table A" shown subsequently, the table lists the data developed or obtained during axial compression tests conducted on three different structural sections. Each section had a height of 76.2 mm (3") and a width of 38.7 mm (1 * 2"). The test specimens included a truss cord or roof frame having a section with projections according to the preferred embodiment of the invention shown in Figure 1, a section with hems as shown in Figure 6 and the patent. of Dry, and a simple "U" shaped section that comprised a shape having a horizontal segment and two legs spaced apart that did not have aggregate stiffening means such as hems or projections. Simple "U" -shaped test sections were formed from strips of 304.8 mm x 190.5 mm (12"x 1") width of a 0.87 mm and 0.75 mm metal sheet (20 gauge and 22 gauge), the hemmed sections were formed from 304.8 mm x 219.08 mm (12"x 8.625") strips of a 0.87 mm and 0.75 mm metal sheet (20 and 22 gauge), and sections with projections were formed using strips of width of 304.8 mm x 250.83 mm (12"x 9.875") and of a metal sheet of 0.87 mm and 0.75 mm (20 and 22 gauge). Three sections of 0.87 mm (20 gauge) and three sections of 0.75 mm (22 gauge) were tested for each of the three different forms, and the tests were carried out in accordance with the accepted AISI standard "Stub_ Column Test Method for Effective Area of Cold Formed Steel Columns ". The test data in "Table A" clearly shows that the projections pointing inward 16 of the present greatly improve the properties of the section on the cords of roof trusses or roof frames of the prior art taught by Dry and Dale »Referring to the test results, the last three loads recorded for each series of f ». «TaMfxé &? Mfet tests were averaged and then divided by the linear inches of the material used to form the configuration to determine the efficiency of the shape (see Average Load (kg) / (linear cm). It was found that the hemmed shape is less Efficient than the simple "U" shape that has no hems or projections that provide rigidity It was also found that the protruding shape of the present invention is up to two minutes more efficient than the hemmed shape. fifteen twenty ^ É | gÉß ^ íÉ ^^ gÉg ^ gg «É¡g Table A It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects to which it refers.

Having described the invention as above, property is claimed as contained in the following

Claims (15)

3* CLAIMS

1. A structural section comprising: a first leg and a second leg, which are spaced apart from the first leg and connected to it by a horizontal segment, the first leg and the second leg each comprising: i) a first end portion fixed to the horizontal segment, ii) a second end portion opposite the first end portion and including a projection extending in an inward direction from the second end portion, and iii) a longitudinal securing surface extending along the leg between the first end portion and the second end portion, characterized in that the longitudinal securing surface faces inwardly and is positioned within said projection so that a distance between the projections of the first leg and the second leg is greater than a distance between the longitudinal securing surface extending thereon. length of the first leg and the second leg.

2. The structural section according to claim 1, characterized in that the projection extending inwardly from the second end portion includes: a) a flat segment extending inwardly from the second end portion; Y b) a terminal end spaced out from the longitudinal securing surface to provide a gap between the terminal end and the longitudinal surface.

3. The structural section according to claim 2, characterized in that the terminal end is a perpendicular leg extending in a downward direction from the flat segment. >

4. The "structural" section according to claim 2, characterized in that the terminal end is an inclined leg extending in a downward direction from the flat segment, the inclined leg has a slope towards the longitudinal securing surface.

5. The structural section according to claim 2, characterized in that the terminal end is an inclined leg extending in a downward direction from the flat segment, the inclined leg has a slope away from the longitudinal surface.

6. The structural section according to claim 2, characterized in that the terminal end is a curvilinear shape extending in a downward direction from the flat segment.

7. The structural section according to any preceding claim, characterized in that each projection extends inwardly from the second end portion toward a central line of the structural section.

8. The structural section according to any preceding claim, characterized in that: a) the distance between the longitudinal securing surface of the first leg and the longitudinal securing surface of the second leg is predetermined because the longitudinal surfaces couple a brace inserted between the first leg and the second leg, and b) the projection extending inwardly from the second end portion is positioned to provide a gap between a strut coupled by the longitudinal surfaces, and the projection extending inwardly.

9. The structural section according to claim 8, characterized in that each of the longitudinal securing surfaces is spaced far apart to be secured to a stringer inserted between the first leg and the second leg, each of which has a length of at least one leg. The longitudinal surfaces are positioned to locate the fasteners inside the first leg and inside the second leg.

10. A truss or frame for the roof that includes the structural section of claim 1, characterized in that the structural section is a rope element and the truss or frame for the roof includes: a) an upper rope element, b) a lower rope element; Y c) a plurality of truss elements for the roof extending between the Upper String and the lower stringer, each element of the roof truss or frame having an external dimension equal to the distance between the longitudinal surfaces that is They extend along the first leg and the second leg.

11. A cer-dfPf * or roof frame according to claim 10, characterized in that it includes: a) a first gap extending between the projection of the first leg and each interlocking element of the truss or roof framework extending between the upper and lower chords; Y b) a second gap extending between the projection of the second leg and each interlocking element of the truss or roof frame that extends between the upper rope and the lower rope.

12. A truss or frame for the roof according to claim 11, characterized in that each of the longitudinal securing surfaces is secured to the cord of the truss or roof frame inserted between the first leg and the second leg, each of The longitudinal surfaces are positioned to locate the fasteners inside the first leg and inside the second leg.

13. A. roof frame or frame, characterized in that it includes the structural section according to any of claims 1 to 9 as a rope of the truss ^ frame for the roof of the floor, in particular the upper and lower strings of the truss or frame for the roof. the roof of the floor.

14. A wall assembly, characterized in that it includes the structural section according to claims 1 to 9 as a tread element or a stud element.

15. A top assembly, characterized in that it includes the structural section according to any of claims 1 to 9 as an element of the rope, in particular a top header rope on a window opening. , ¿S * ¿* * * * ^ * M »~ * * ~. The present invention relates to a structural section (10) for He t, i * iso in a framework construction wherein the section includes a horizontal segment (11) and a pair of legs spaced apart (12a, 12b). Each leg has a first end portion (13) fixed to the horizontal segment, a second end portion (14) opposite the horizontal segment, and a 10 projection (16) extending inward from the second end portion toward the center line of the structural section. Each leg further includes a longitudinal surface (15) located between the first end portion and the second end portion. The The longitudinal surface is positioned within the projections so that the distance between the opposing protrusions extending along each leg of the structural section is greater than the distance between the opposing longitudinal surfaces extending as far as possible. 20 length of each leg of the structural section. ^ ^^^ g ^^ 'j ^^^' *