JPH0254048A - Trussed girder of wood and metal - Google Patents

Abstract

PURPOSE: To economically and accurately fabricate a truss so as to provide an optimum inertia to a lightweight mass by interconnecting wood members through the means of fasteners which grip the flat part of a metal tube folded in a staggered fashion. CONSTITUTION: Two members 1, 2 are interconnected by a diagonal bar 3 which constitutes a truss. The truss comprises a metal tube 4 folded in a staggered fashion. The part of the folded tube 4 connected to the members 1, 2 is formed into a flat shape, and an upper elbow is connected to the upper wood member 1 by a metallic fastener 5, while a lower elbow is similarly connected to the lower wood member 2 by a metal fastener 6.

Description

[Detailed Description of the Invention] More specifically, the invention relates to a beam having two wooden members connected together by a truss of metal diagonal bars.

This type of "wood and metal" composite beam is already known, particularly in the following two forms.

In a first known embodiment, two wooden members are connected to each other by a sinusoidal metal wire connection.

The bottom and top of the "corrugations" formed by the metal wire are embedded and glued into the wood of the component. This beam structure has a weak resistance to buckling because the truss is made of a single metal wire and has small dimensions. Such a beam structure is only expected to be used when the dimensions, especially the span, are small, and therefore its use is greatly limited.

In addition, the implementation of this type of truss beam depends on the quality of the adhesive bonding the metal wire onto the wooden member, and therefore requires great care and is expensive to manufacture.

In a second known "wood-plus-metal" composite beam embodiment, the two wooden members have metal sides that are secured against the sides of the two members in a "V" shape. are connected to each other by connectors.

The fixation of the connector to the member is carried out by means of a clasp, and the mechanical properties of the beam in this case depend on the quality of the clasp. Therefore, the components must be constructed from high quality and therefore expensive wood, especially wood with a low knot ratio. Also, when it comes to metal connectors, special preparation is required, including swaging, to create the scratch stop marks. This arrangement also reduces the accessibility of the sides of the part and complicates the assembly of such beams with other elements.

The present invention aims to eliminate all the inconveniences of these currently known embodiments.

Therefore, in the wood and metal truss beams that form the object of the invention, the truss is composed of metal tubes that are folded in a zigzag pattern, successive pieces of which constitute diagonal bars, The elbow has flat sections which are connected alternately to the two wooden members by means of a fastener which each grips one of the members and the flat section of the zigzag metal tube.

Thus, beam trusses can be made economically and accurately by starting with a straight tube, flattening the tube at regular intervals, and then folding the tube into a zigzag pattern. By using a tube in this way, it is possible to obtain an optimal inertia for a light mass (the inertia can be changed by changing the thickness of the tube), and furthermore, the applied force is
It is distributed over the entire length of the wooden member with a homogeneous function, and the sides of the member are completely freed.

Such advantageous effects are most noticeable when the following arrangement is adopted for and(.

, j The metal tube folded into a zigzag shape has an oval cross section,
Its largest diameter extends transversely to the common plane of the beams. The oval cross section facilitates the task of flattening the tube and also maximizes the space available for placing other elements such as conduits through the beam.

- In the case of a beam that uses two wooden members with a rectangular cross section, the flat part of the metal tube folded in a zigzag shape is the width of each member! The flat parts of the metal tubes, although of equal width, are further resisted against the "knots" of the structure by means of a fastener that grips one of the members and the flat part of the zigzag-folded metal tube, respectively. , and makes it possible to make simple mechanical connections. In this case, it is especially advantageous to make metal fasteners, for example from steel strips, and to close their upper parts by welding. The welding of each fastener is done next to the metal part in full contact, so there is no risk of burning the wood of the component.

This welding process can be performed using any method such as the "laser method" or the "microplasma method."

It is advantageous if the fastener is installed by locally crushing two wooden members. In this case, if metal pipes bent in a zigzag pattern are used to connect the members, the pieces of wood will be connected together, and the density and resistance of the wood will locally increase.

Preferably, the local crushing of the wood of the member is done so that the fastener penetrates into the original volume of the member, so that the surface of the wood is smooth without any protrusions, and the beam is smooth. 5 to make it easier to assemble with adjacent parts. If you are busy like this, you will be able to do the true tsuka-komi process, which involves tightly joining wooden parts and metal parts together.

The "node" of the truss beam, which is the object of the present invention, is preferably composed of two consecutive pieces of a metal tube folded in a zigzag shape, with the length of the flat part of the tube appropriately selected. Ru2
The axes of each of the diagonal book bars are made to meet at a point on the axis of the wooden member, or on the neutral axis of the member.

It is also understood that the length of the flat part of the tube must also correspond to the width of the fastener.
BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood by the following description with reference to the accompanying schematic drawing, which shows by way of example one embodiment of a truss beam according to the invention. However, this embodiment does not limit the scope of the present invention.

The truss beam shown in Figure 1 comprises two members l and 2 made of wood, which in the example shown are straight, parallel to each other, and of the same length. . These two wooden parts 1.2 each have a rectangular cross section - see also FIG. 2.

The two members 1 and 2 are connected to each other by a diagonal bar 3 forming a beam truss. Based on the present invention,
The truss is made of metal and consists of zigzag-folded tubes 4, each straight section of which constitutes one of the diagonal bars 3. The upper elbow of the folded tube 4 is secured to the upper wooden member IK by a metal fastener 5.
Concatenated. The lower elbow of the similarly folded tube 4 is connected to the lower wooden member 2 by a metal fastener 6.

In the example shown in the drawings, the metal tube 4 has an oval cross section - see FIG. 2. The largest diameter of the oval cross section of the tube 4 is oriented transversely to the common plane of the beams.

FIGS. 2 and 3 show more precisely the "knots" of the beam, i.e. where two successive diagonal bars 3 are connected to one member 2 by a fastener 6. FIGS. In this part, the tube 4 has a flat shape as indicated by 7. The clamp 6 grips the member 2 and the flat part 7 of the tube 4, which flat part has a width approximately equal to the width of the member 2.

The fastener 6 is closed at its top by a longitudinal weld 8 made at its top between the ends of the two rods 3. The width of the fastener 6 is comparable to the length of the flat part 7 of the tube 4.

The attachment of this fastener 6 is indicated by arrows 9 and l.

As shown in , this is carried out by locally crushing (fitting) the surface of the wooden member 20. As a result, the fastener 6 is pushed into the original volume of the member 20 with a voltage of 5 Vc. When installed and in the final state of the beam, the member 2 must maintain a smooth plane.This fastener 6
The resulting compression ensures assembly integrity and stress distribution. In this regard, it should be noted that in the preferred arrangement, the axes 11 and 12 of each of the two consecutive diagonal bars 3 converge at a point on the axis 13 and thus on the neutral axis of the member 2.

The wood and metal truss beams described above are particularly applicable to the construction of various covered structures in the fields of architecture and civil engineering.

This beam can be used alone or with other similar beams to form two-dimensional or three-dimensional structures.

As is clear, the invention is not limited to the single embodiment of the truss beam described by way of example. On the contrary, the invention includes all variants of implementation and application based on the same M principle. In particular, the following does not depart from the scope of the invention.

- providing wooden members 1 and 2 of different lengths, in particular the lower member 2 shorter than k to create a boat-shaped beam;

By modifying the cross sections of the wooden members 1 and 2, (for these members, rounded corners or rectangular cross sections are arranged, and the flat part 7 of the metal tube 4 bent in a zigzag shape and the member 1 and 2
Wrap the fasteners 5 and 6 connecting the parts 5KL around the member to facilitate attachment of the fasteners.

- modifying the cross section of the metal tube 4 or the angle of inclination of the oblique bar formed by this tube;

Various modifications are made to the ends of beams for supporting, erecting, or fitting them.

[Brief explanation of the drawing]

FIG. 1 is a front view of a wood and metal truss beam in accordance with the present invention. FIG. 2 is a partial perspective view showing details of the beam in FIG. 1. FIG. 3 is a longitudinal sectional view of the beam portion shown in FIG. 2. 1.2... Member, 3... Diagonal bar, 4...
Metal tube, 5.6... Fastener, 7... Engraving of flat part mx (no change in content) Procedural amendment (method) 1. Indication of the case 1988 Patent Application No. 204906 2, Name of the invention Wood and gold truss beam 3, Person making the amendment Relationship to the case Patent applicant address 7-)7A5.38230・BO/・DO・Shelley, Rue de U Liberté, 37 Name: Fenol φ Engineering 4, Agent

Claims (1)

[Claims] 1. In a wood and metal truss beam having two wooden members (1, 2) connected to each other by a truss of diagonal metal bars, the truss is folded in a zigzag shape. , a metal tube (4) whose successive pieces constitute a diagonal bar (3)
The elbow of the folded metal tube (4) has a flattened portion (7), each of which connects the folded metal tube (4) in a zigzag manner with one of the members (1, 2). flat part (7)
The two wooden members (
A truss beam characterized by being alternately connected to 1 and 2). 2. Wood and metal truss beam according to claim 1, in which the zigzag-folded metal tube (4) has an elliptical cross section, the largest diameter of which is transverse to the common plane of the beam. A transformer beam that is characterized by extending in the direction. 3. Wooden 2 having a rectangular cross section according to claim 1 or 2.
In a wood and metal truss beam with regular members (1, 2), the flat part (7) of the metal tube (4) folded in a zigzag shape is approximately equal to the width of each member (1, 2). A truss beam characterized by: 4. In the wood and metal truss beam according to any one of claims 1 to 3, the wooden members (1, 2) and the flat part (7) of the metal tube (4) folded in a zigzag shape Truss beam, characterized in that the connecting fasteners (5, 6) are metal fasteners, which are closed by welding (8) thereon. 5. A wood and metal truss beam according to claim 4, in which the welding of each fastener (5, 6)
A truss beam characterized in that it is carried out between the ends of two diagonal bars (3) adjacent to the flat part (7) of a tube (4) held by. 6. Wood and metal truss beam according to any one of claims 1 to 5, in which the length of the flat part (7) of the tube (4) corresponds to the width of the fasteners (5, 6). A truss beam characterized by: 7. In the wood and metal truss beam according to any one of claims 1 to 6, the fasteners (5, 6) are capable of compressing the wooden members (1, 2) by locally crushing them. A truss beam characterized by the fact that it can be installed as a truss beam. 8. Wood and metal truss beam according to claim 7, in which the local crushing of the wood of the members (1, 2) causes the fasteners (5, 6) to A truss beam that is designed to cut into the interior. 9. In the wood and metal truss beam according to any one of claims 1 to 8, the metal tube (
The respective axes (11, 12) of two diagonal bars (3) constituted by two consecutive pieces of 4) are on the axis (13) of one wooden member (1, 2). A truss beam that is characterized by converging at a certain point. 10. In the wood and metal truss beam according to any one of claims 1 to 9, two wooden members (1, 2)
has a substantially rectangular cross section with rounded corners, and the member (1
, 2) of the metal tube (4) folded into a zigzag shape (
7) A truss beam characterized in that the fasteners (5, 6) connected to the member are wrapped around the member.