GB2024909A

GB2024909A - A beam having flanges of wood and a web of metal, and a method of making it

Info

Publication number: GB2024909A
Application number: GB7922351A
Authority: GB
Original assignee: KINDBERG BA
Current assignee: KINDBERG BA
Priority date: 1978-07-03
Filing date: 1979-06-27
Publication date: 1980-01-16
Also published as: FR2430565A1; DE2926270A1; FR2430565B1; SE428225B; SE7807478L; GB2024909B

Abstract

A beam consists of two identical parts each comprising two parallel wooden laths (10, 11), interconnected by U-shaped retainer means (12) the flanges (14, 15) of which are driven each into one lath (10, 11). The two identical parts are joined together by gluing of the surfaces (16, 17) into which the flanges (14, 15) of the retainer means are driven. The beam is produced by laths (10, 11) being continuously fed in parallel, spaced- apart relationship, during which the flanges (14, 15) of the U-shaped retainer means (12) are driven each into one lath (10, 11). The interconnected pair of laths is attached to a similar pair of laths (10, 11) of the same length by gluing together the surfaces into which the flanges of the retainer means have been driven in. <IMAGE>

Description

SPECIFICATION A beam having flanges of wood and a web of metal, and a method of making it The present invention relates to a beam having flanges of wood, each comprising two longitudinal laths joined by gluing, and a web of metal interconnecting the flanges.

Beams with flanges of wood and a web of metal are previously known. Normally they are manufactured in large dimensions with webforming means screwed or nailed on to the flanges, for instance in special recesses provided for this purpose. It is also already known, however, to make beams of this type in smaller dimensions, as appears from Swedish Patent application 7610600-4. The web of this beam consists of steel wire bent in zigzag, the bends of said wire being lodged in recesses made for this purpose in the beam flanges each of which comprises two laths joined together by gluing, the recesses for the bends of the web wire being provided in one or both of the lath surfaces which are united by gluing to form the beam flange.A beam of this design is less expensive than beams of solid wood of corresponding dimensions but like the larger beam this beam has a lower limit which, for economic and dimensional reasons, should not be passed.

The object of the present invention therefore is to provide a beam which can be manufactured at a most competitive price also with dimensions considerably below said limit, primarily because the web is of simpler construction. In this way there is obtained a complement to the abovementioned large and medium sized beams.

The object of the invention is achieved in that a beam is provided consisting of two identical parts, each comprising two laths which are interconnected by U-shaped retainer means of metal which are spaced apart from one another in the longitudinal direction of the laths and the branches of which, together with the web portion adjacent said branches, are driven in each into one lath in such a way that the boundary surface of the web facing way from the branches will coincide with or be situated inwardly of the lath surface into which the branch and the adjacent web portion are driven, and that the parts are joined by gluing of the lath surfaces into which the Ubranches and web portions are driven.

The invention also relates to a method of making a beam with wooden flanges, comprising each two longitudinal laths joined with one another by gluing, and a beam web of metal interconnecting the flanges. Characteristic of this method is that the laths are fed continuously in two parallel, spaced-apart paths, that the laths are interconnected by U-shaped retainer means of metal in that a U-branch is driven into either lath, the branches and the adjacent web portion being driven in so far into the associated lath that the boundary surface of the U-web facing away from the respective branch will coincide with or be situated inwardly of the lath surface into which the branch is driven, and that a pair of laths of predetermined length interconnected in this way is joined with a similar pair of laths of the same length by gluing together the surfaces into which the U-branches have been driven.

The invention will be described in greater detail hereinbelow with reference to the accompanying drawing which shows an example of embodiment and in which: Fig 1 is a front view of one part of a beam according to the invention; Fig 2 shows this beam part as seen from one end; Fig 3 is a front view of a completed beam according to the invention; and Fig 4 shows the beam according to Fig 3 as seen from one end.

The beam of the invention consists, as appears from Fig 4, of two indentical beam parts. Each of these parts comprises two laths 10 and 11 which extend in parallel at some distance from each other and are interconnected by U-shaped retainer means 12 or clamps. The retainer means 12 have each one web 13 and, at the ends of the web, branches 14 and 15 formed integrally with the web. The laths 10 and 11 are united with each other by the retainer means 12 being driven into the sides, designated 16 and 17, of the laths 11 and 10 respectively. It is not only the branches 14, 1 5 but also the portions of the web 1 3 adjacent the branches 14, 1 5 that are driven into the laths, as appears in greater detail from Fig 2.The retainers 12 are driven in so far that the surface of the web 13 facing away from the branches 14, 1 5 will be situated in the plane of these surfaces 16, 1 7. The branches 14, 15 can also be driven in so far that said web surface will be situated somewhat inwardly of the surfaces 16, 17. The retainer means 12 are preferably driven in so that they will make a predetermined angle relative to the longitudinal direction of the laths, said angle being about 500 in the embodiment shown in the drawing. Of course, the web of the retainers 12 can also make right angles to the longitudinal direction of the laths but preferably some angle between 300 and 750 is chosen depending upon the purpose for which the beam is to be used.

A pre-requisite for allowing a beam according to the invention to be manufactured at a low price resides in continuous production. According to the invention, laths 10 and 11 are fed continuously in two parallel paths spaced apart at a distance depending on the dimensions of the beam to be made. The laths 10, 11 may consist of short pieces which are jointed, e.g. according to the finger-jointing method. During the continuous movement of the laths 10, 11 the U-shaped retainer means 12 are driven in by means of a conventional machine. The distance between the retainer means 1 2 depends on the expected load on the beam.In the embodiment shown the distance between the retainer means 12 exceeds the length of the projection thereof on a plane which is parallel with the laths 10, 11 but the distance between the retainer means 12 may of course be both greater and smaller. It is not either necessary to provide all the retainer means 12 with the same inclination.

The beam half, which emerges from the manufacturing machine and which consists of the laths 10, 11 and the retainer means 12, is cut to lengths adapted to the intended use. A beam of the design shown in Figs 3 and 4 is composed of two such lengths of the embodiment shown in Figs 1 and 2 in that one length is turned so that the lath surfaces 16, 17 of the turned length can be placed against the corresponding lath surfaces of the unturned length, as shown in Fig 4. Since the retainer means 12 have been driven in as described, these surfaces have no projecting parts and are therefore well suited for gluing, which is carried out by means of water-resistant glue in a press adapted for this purpose. The beam shown in Figs 3 and 4 is obtained by gluing together of these surfaces, the web of said beam being formed of the U-shaped retainer means 12 which, due to the fact that one beam half has been turned, incline alternately in opposite directions with the retainer means in one beam part situated half-way between the retainer means in the other beam part, as appears from Fig 3.

As pointed out above the retainer means 12 can be driven into the laths 10, 11 with different inclination and at different intervals and therefore the beam web may be easily adjusted to the expected load.

It appears from the foregoing that the invention makes it possible to produce a very simple and cheap beam which is particularly fit for use as an internal wall stud in the construction of buildings and can be manufactured with small flange dimensions at a low price.

Claims

1. A beam having flanges of wood, each comprising two longitudinal laths joined by gluing, and a web of metal interconnecting the flanges, wherein the beam consists of two identical parts, each comprising two laths which are interconnected by U-shaped retainer means of metal which are spaced apart from one another in the longitudinal direction of the laths and the branches of which, together with the web portion adjacent said branches, are driven in each into one lath in such a way that the boundary surface of the web facing away from the branches will coincide with or be situated inwardly of the lath surface into which the branch and said web portion are driven, and the parts are joined by gluing the lath surfaces into which the U-branches and web portions are driven.

2. A beam as claimed in claim 1, wherein the web direction of the U-shaped means makes an angle of 30 -- 750, preferably about 500, relative to the longitudinal direction of the laths.

3. A beam as claimed in claim 2, wherein the Ushaped retainer means are driven into the laths at intervals exceeding the length of the projection of a retainer means on a plane which is parallel with the longitudinal direction of the laths and the retainer means in one beam part are placed halfway between the retainer means in the other beam part.

4. A beam substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

5. A method of making a beam having flanges of wood, comprising each two longitudinal laths joined with one another by gluing, and a beam web of metal interconnecting the flanges, wherein laths are fed continuously in two parallel, spacedapart paths, the laths in the two paths are interconnected by U-shaped retainer means of metal in that a U-branch is driven into either lath, the branches and the adjacent web portion being driven in so far into the associated lath that the boundary surface of the U-web facing away from the respective branch will coincide with or be situated inwardly of the lath surface into which the branch is driven and a pair of laths of predetermined length interconnected in this way is joined with a similar pair of laths of the same length by gluing together the surfaces into which the U-branches have been driven.

6. A method as claimed in claim 5, wherein the U-shaped retainer means are driven in with the web direction making an angle of 30 -- 750, preferably about 500, relative to the longitudinal direction of the laths.

7. A method as claimed in claim 6, wherein the U-shaped retainer means are driven into the laths at equal intervals exceeding the length of the projection of a retainer means on a plane which is parallel with the longitudinal direction of the laths, and the retainer means in one beam part are placed half-way between the retainer means in the other beam part during the gluing operation.

8. A method of making a beam substantially as hereinbefore described with reference to the accompanying drawings.