FR2461071A1 - PERFECTED BEAM - Google Patents

Abstract

THE INVENTION RELATES TO BEAMS USED IN CONSTRUCTION. THE OBJECT OF IT IS AN EXTRUDED ALUMINUM BEAM, HAVING AN UPPER PART IN THE FORM OF AN UPPER CAP, A CENTRAL CORE AND A LOWER PART IN WHICH IS A CENTRAL CHANNEL INTENDED TO RECEIVE A BOLT HEAD. THE BEAM HAS TWO BOTTOMS EXTENDING DOWNWARDED AT THE OUTER ENDS OF EACH OF THE UPPER CAP EDGES, AND TWO UPWARDS EXTENDING EDGES AT THE UPPER ENDS OF EACH OF THE EXTENDING LOWER EDGES. APPLICATION IN PARTICULAR TO THE REALIZATION OF CONCRETE FORMWORK.

Description

The present invention relates to an extruded aluminum beam

  developed having very high strength and stiffness / weight ratios, and being particularly suitable for use as a beam in concrete forming applications. Structures for concrete shaping

  have been previously proposed to support and

  storing the formwork for pouring concrete,

  horizontally as in floors of appar-

  ment and the like, and vertically as in

  walls or coverings of galleries, and the like. Gene-

  In general, horizontal shoring is

  set of secondary joists that can be suppora-

  main supports such as armatures or

  beams that are supported by vertical struts.

  For the vertical shoring can be used several beams or molds which are, in turn, supported

  by resistant struts or the like. The secondary struts

  may be permanently attached to the main supports

  especially in cases where shoring or concrete shaping

  from a first working position in a se-

later position.

  There are cases where it is desirable to place heavier concrete loads than normal, such as

  than in garages or door-to-door structures

  large fake, and the like. In such cases, it is very often desirable to provide shoring transmitting the concrete load to vertical struts, which may not necessarily be reinforcements when the situation may require only temporary special shoring. In such circumstances, scaffolding is often provided by scaffolding and may

intermediate poles.

  In such cases, in the past, the usual practice has been to provide wood or steel beams, which are necessarily very heavy, thus making it difficult to handle the beam and its implementation in working position, requiring a

  important workforce and taking time.

  One of the aims of the present invention is to provide an extruded aluminum beam having high strength and rigidity, but such that it can be handled on a building site by a

only man.

  Another object of the present invention is to provide a beam which can be used as a

as joist.

  The foregoing objects and features are achieved by providing an extruded aluminum beam having a

  overturned hat, a central soul and an inferior part

  in which there is a centrally arranged canal

  ideally suited for receiving a bolt head. The beam of the present invention is extruded aluminum of constant cross-section along its entire length, and in particular has two downwardly extending flanges which are made at the outer ends of each of the rims of the upper cap, and two flanges of extending upwardly which are made at the outer ends of each of the outwardly extending lower flanges. The heights of all the flanges extending downward and upward are substantially equal between

  they. The minimum thickness of each edge is

  stretching outward from the top, that is

  ie the edges of the upper cap, is larger than the minimum thickness of each of the flanges

  lower; and the thickness of each of the flanges

  tending inwards, which delimit the receiving slot of the bolt in the lower part, is larger than the minimum thickness of each of the flanges

  lower lying externally.

  In a preferred embodiment, the sur-

  lower faces of each of the flanges, extending externally, of the upper part, that is to say

  the edges of the upper hat are curved, tan-

  say that the load-bearing upper surfaces are substantially planar. Similarly, the upper surfaces of the flanges, extending externally,

  of the lower part are curved at their ends.

  external dies with substantially the same radius of curvature as the outer ends of the lower surfaces of the rims of the top cap, so that identical fasteners may be used to secure the beam to other structures,

as may be necessary.

  The present invention is described hereinafter

  in more detail, with reference to the attached drawings.

  Figure 1 is a perspective view of a beam according to the present invention, showing the

  characteristics and main features of it.

  30. Figure 2 is an end view of a beam according to the present invention having a

  wooden joist fixed in its upper part.

  Figure 3 is a perspective view showing the beam in association with other building elements in a typical example

use of the beam.

  Referring first to Figures 1 and 2, on which is shown a beam 10 according to the present invention, which is made of extruded aluminum, and subjected only to the usual conditions of extrusion and manufacturing, has a

  constant cross section over its entire length.

  The beam has an upper portion 12, a

  core 14 and a lower part 16.

  The upper portion 12 has a substantially U-shaped channel 18, with a bottom wall and side walls 22, and two laterally outwardly extending flanges 24, one from the upper end of each of the side walls.

22.

  The core 14 is located substantially centrally below the upper portion 12 and above the lower portion 16, and has a core 26 which is

  of substantially constant thickness over its entire

  except in its transitions 28 and 30 with the

  upper part 12 and the lower part 16, respectively

is lying.

  The lower part has a 32 channel

  placed centrally suitable for receiving the head of a bolt, and it is evident that the channel 32 is substantially smaller at a time in width

  and in height as the channel 18. The channel 32 is de-

  limited in particular by two short edges 34 extending laterally inwardly, one since

  each of the lower ends of the side walls

  the 36 of the canal 32. Two lower edges 38

  tend towards the outside, one from each

  lower end of the side walls 36 of the channel.

  The overall width of the lower flanges 38 is greater than

  greater than the overall width of the upper flanges 24, i.e., the lower flanges 38 extend over a larger extent than the upper flanges 24. The lower surfaces of the lower flanges 38 are generally on one side to the other, slightly concave. Thus, when the beam is at rest and otherwise free of contraites, the short edges 34 which serve to delimit the channel 32 of bolt head are higher than the outer edges of the

  lower surfaces of lower edges 38.

  As indicated above, the main requirements

  cipales of the beam are that it presents to the

  resistance and rigidity, as

  above, and that these characteristics are considerably higher, relative to the weight, than, for example, in the case of wooden beams.

or steel.

  These additional features are presented in particular by a beam according to the

  present invention, which in addition to the description

  The foregoing has the following characteristics At the outer ends of each of the outwardly extending flanges 24 of the upper portion 12 of the beam, a flange is formed

  extending down. Similarly, at the extremes

  outer tees of each of the lower flanges 38, is formed a rim 42 extending upwards. The heights of all the flanges 40 and 42 extending

  downward and upward are substantially identical

c.

  The upper flanges 24 extending outwardly

  have substantially larger surface areas than

  nes, which act as load-receiving surfaces in normal use of the beam. The lower surfaces of the flanges 24 may be flat, or in the preferred embodiment they

246 1071

  are curved as in 44. In each step, the thick

  The minimum amount of flanges 24 is greater than the thickness

  minimum requirement for one of the lower edges 38.

  Similarly, the thickness of the flanges 34, which delimit the slot 32 for receiving a bolt, is greater than the minimum thickness of each of the

lower edges 38.

  It has been stated that the lower flanges 38 have a minimum thickness; and in the preferred embodiment of the beam according to the present invention, the outer ends of the upper surfaces of the lower flanges 58 have a step 46, so that the outer portions 48 are curved with the same radius of curvature as the outer ends. the curved portion 44

  24. In this way, the flanges 40 are

  tending downwards and the upwardly extending flanges 42, or vice versa, may receive fasteners

  identical, as explained below.

  In some cases, in particular, when the beam is intended to be used as a joist, or where it may be advantageous to fix another element to the beam by fasteners that can be driven into a wooden joist or the like, a piece of wood 54, nominally 31 mm x 31 mm, can be pushed down into the channel 18 in such a way as to favor fixing of the recessed part, in particular so as to oppose the upward movement of the latter, teeth 50 may be provided on the inner surface of the side walls 22 of the upper channel 18, or on one or other of these surfaces. Depressible members, such as screws 52, may also be driven into the wood piece 54, and these clips 52 may be driven from a groove or indentation 56 formed in the outer surface of the walls 22 or in the wall. one or the other of these. The consequences of the aforementioned features and characteristics of a beam according to the present invention are physically demonstrated in a beam having a normalized (nominal) overall height of mm, an overall width at the base of 127 mm, and an overall width of one edge to the other of the upper flanges of 98.4 mm. This beam has a moment of resistance which is substantially equivalent to that of a piece of fir wood of 304.8 mm x 304.8 mm, which weighs 44.65 kg / m, in dry weight, while weighing only 7 , 7 kg / m completed with one piece

  recessed wood of 38.1 mm x 38.1 mm.

  Compared with a standard "ALUMA" beam, substantially as described in US Pat. No. 3,787,020 of January 22, 1974, the moment of inertia about the horizontal axis (Ix) is 1417 cm4 in comparison to

  685 cm4; and a moment of inertia around the vertical axis

  tical (I) of 196 cm4 in comparison with 105 cm4.

  Such an "ALUMA" beam has a weight of 6.0 OW and has an overall height (nominal) of 165 mm, an overall width at the base of 127 mm and an overall width from one edge to the other of upper edges of 80 mm. Thus, quite surprisingly, for a weight increase of only about 30%, a much higher Ixx and Iyy are obtained, giving the following comparative figures.

  with regard to the strength and rigidity

  from which it can be seen that the beam of the present invention exhibits increases in strength and stiffness of about 100% for

  the increase of 30% by weight indicated.

Table 1

  Comparison of a beam ALUMA-to the beam

  of the present invention (with respect to the characteristics

of the ALUMA beam)

  Referring now to Figure 3 on which

  is represented a typical use of the

  in accordance with the present invention, together with

  a standard "IALUMA" powder as indicated above.

  above. The beam 10 can be supported since the

  below by another shoring device, such as -

  high-strength scaffolding, shoring poles or the like, and is generally supported in a

  U-shaped head 58 which is associated with vertical shoring 74.

  The beam can be inserted into U-shaped heads

  standard of the type commonly encountered on

  third of construction, upside down in the case of a 101.6 mm U-shaped head; not reversed for the wider U-shaped head of 203.2 mm. Moreover, the beam can be fixed to a plate instead of being in a U-shaped head, by a fastener such as

the fastener 62 mentioned below.

  A set of beams 60 are supported by Poutrelle POUTRE of ALUMA present invention Weight per unit length

(including the report

  wooden shaft) 1.0 1.3 Resistance to sag 1.0 2.0 Strength moment 1.0 1.85 - Beam 10, and similar beams spaced from it along beams 60. Beams 60 may be attached to the beam 10 using fasteners 62 which are designed and intended to be attached to the underside of the beam by introducing a bolt head into a slot 66 for it and screwing a nut 64 onto the bolt . The clamping portion 68 of the clip 62 covers the downwardly extending flange 40 for final attachment of the beam 60 to the beam 10 if they are to be moved together. Either pairs of fasteners 62 may be used on both sides of the beam 10, or fasteners on successive beams may be on alternate sides of the beam, using only one beam and beam fastener. In the typical arrangement shown in Figure 3, a liner 70 is attached to the beams 60 by depressible fasteners penetrating down through the liner 70 into a wooden insert 72 placed and secured in the upper portions. Hat-shaped each

beams 60.

  By using the beam 10 in the manner shown in FIG. 3, it is not necessary to insert blocks between the walls extending towards

  the top of the U-shaped head 58 and the core 26 of the beam.

Claims (4)

R E V E N D I C A T I 0 N S   1. Extruded aluminum section beam   constant cross-section throughout its length, possessed   an upper part, a soul and a lower part; o the upper part has a substantially U-shaped channel with an inferior wall   upper and side walls, and two   extending laterally outwardly, each from the upper end of each of the sidewalls;   o the soul is located substantially centrally   below said upper part and above   said lower part, and is of substantial thickness   constant, except in its transitions with the   upper and lower parts; o the lower part   The channel has a centrally disposed channel capable of receiving the head of a bolt, said channel being of substantially less width and height than the channel of the upper portion; o two short edges extend laterally inwardly each from the lower end of each of the side walls   the channel of said lower part; and o two   edges extend laterally outwardly, each from the lower end of each of the side walls of the channel of said lower portion, on a   overall range greater than the two edges that   tend towards the outside from the ex-   upper trenity of the side walls of the channel of said upper part; the lower surfaces of said flanges of said lower portion being generally slightly concave from side to side; said beam being characterized in that two downwardly extending flanges are formed at the outer ends of each of the outwardly extending flanges of the upper portion, and in that two upwardly extending flanges are formed the   outer ends of each of the flanges extend   outside-the-bottom; the heights of all the upwardly and upwardly extending flanges being substantially equal to each other; in that the minimum thickness of each of the   ledges extending outwards from the upper part   is greater than the minimum thickness of each of the flanges extending outwardly from the bottom; and in that the thickness of each   short edges extending internally from the   lower bound is greater than the minimum thickness   from each of the edges of it extending towards the former TER AL.   Beam according to claim 1, characterized   in that several teeth extending towards the interior   and at the bottom are made in part of at least one of the side walls of the channel of the   upper part of said beam.   5. Beam according to claim 1, characterized   characterized in that the lower surfaces of each of said two outwardly extending flanges of said upper portion are curved, and that the upper surfaces thereof are substantially planar.   4. Beam according to claim 3, characterized   in that the upper surfaces of the flanges extending outwardly from the lower portion are   curved at their outer ends with sensi-   the same radius of curvature as that of the   outer half of the lower surfaces of the ledges   extending outwardly from the top.