In the art of building materials there is known a structural component intended for wall structures which comprises an elongated box-like element having two mutual¬ ly opposing side members which define a cavity therebetween and the mutually facing inner surfaces of which present longitudinally extendinα grooves, and between which side members there are located distance pieces having projec¬ tions which engage in the grooves.

In the manufacture of structural components of this kind it has been necessary to employ hitherto methods which can be described more or less as handicraft methods, which has made manufacture a slow and expensive process.

One object of the present invention is to provide a method and a machine for enabling the continuous manufac- ture of such structural components in. a rational fashion.

The method and machine according to the invention can also be utilized to manufacture a further development of the aforesaid structural component intended for wall struc¬ tures, this modified structural component being suitable for use as a self-supporting floor component and the like. Consequently, a further object of the invention is to provide a structural component of the aforedescribed kind which is capable of being used as a component in floor structures. One advantage afforded by a structural component of the aforesaid kind is that the component obtains and retains its final form immediately the plate-like distance pieces are brought into engagement with the side members of the component. This advantage is utilized in the method of the manufacture according to the invention, which enables such a structural component to be produced continuously in in¬ definite lengths, and then cut into required lengths.

The method according to the invention for manufactu¬ ring a structural component of the aforesaid kind is parti-

cularly characterized by advancing longitudinally to a receiving station pair ^' s of mutually spaced boards or the like which are operative in forming the side members of the component and which have grooves provided in the mutual- ly facing surfaces thereof; by placing and supporting the plate-like distance pieces on an endless belt extending in the longitudinal ^* direction of the boards and moving said belt at a speed corresponding to the speed at which said boards are advanced; by bringing the distance pieces between the boards of an incoming pair of boards; and by pressing the boards towards one another as they leave the station, so as to bring the projections on the distance pieces into engagement with the grooves in the inwardly facing, surfaces of the boards. In this regard the distance pieces are preferably supported by supporting means mounted on the belt and pro¬ jecting in between the boards.

When manufacturing insulated structural components, insulating foam can be ejected continuously into the afore- said cavity as the building structural component leaves the station for fitting of the aforesaid distance pieces, these distance pieces separating the cavity into a plurality of separate compartments, wherewith the normally open sides of the cavity are held closed with the aid of belts or bands which extend along and are pressed against the edge surfaces of the side members of the component under construction.

The particular characteristic features of a machine for manufacturing a structural component when using this method are set forth in the following claims. The aforementioned further development of the struc¬ tural component described in the introduction for use as a self-supporting floor component or the like, where the side members of the structural component respectively form the top and bottom surfaces of the floor structure, is charac- terized in that each of the side members is provided with an upwardly facing groove which extends along one longitudi¬ nal side edge of the structural component, and with a

correspondingly downwardly depending tongue along the other longitudinal side edge of the component. A tongue and groove joint of this construction, formed at right angles to the plane of the boards, enables the floor components to be joined together readily and simply and also provides a more rigid floor of greater bearing capacity than that obtained when joining the boards together through the agency of con¬ ventional tongue and groove joints located in the plane of the boards. The floor component is also suitably filled with insu¬ lating foam, and can be further reinforced by introducing stiffeners between the plate-like distance pieces.

In accordance with one embodiment, which facilitates, inter alia, laying of the floor components, the top side member is displaced laterally in relation to the bottom side member.

The invention will now be described in more detail with reference to the accompanying drawings, in which - Figure 1 illustrates in perspective the manner of laying a floor component according to the invention;

Figure 2 is an end view corresponding to Figure 1; Figure 3 is a corresponding end view illustrating a modified embodiment of the floor component; and

Figure 4 illustrates schematically the principle construction of a machine for producing box-like structural components.

As illustrated in Figs. 1 and 2, a floor component according to the invention comprises a top side-member 1 and a bottom side-member 2, each of which comprises in this example two mutually joined boards. In a manner known per se each of the side-members 1 and 2 has extending along the inwardly facing surfaces thereof a plurality of longitu¬ dinal grooves, and the boards are mutually joined together in a known manner by distance pieces 3 which engage in the grooves and divide the cavity defined by said side members into separate compartments. The structural component can be stiffened with the aid of braces 4 or like elements arranged

to join mutually adjacent distance pieces 3. The cavity defined by the side members and divided into separate compartments by the distance pieces is suitably filled with insulating foam. The braces 4 may be replaced with other devices, for example with wood-fibre strips which extend in the longitu¬ dinal direction of the boards and engage opposing grooves therein. These strips are conveniently perforated, to en¬ able foam to fill the cavity between the boards completely. The use of stiffening strips arranged in the aforesaid man¬ ner greatly enhances the supporting capacity of the floor structure.

A floor component constructed in this way is extremely rigid, due inter alia to the distance pieces 3, which are suitably spaced apart at distances of about 30 cm. The braces 3, or the alternative stiffening strips, also contri¬ bute to the high degree of rigidity of the floor component, t as does also the foam insulation when present. In order to improve the bearing capacity of a floor constructed from floor components according to the invention still further, however, mutually adjacent components are joined together by means of a novel tongue and groove joint.

Conventional tongue and groove joints include a groove and corresponding tongue which both extends in the plane of the associated boards. In order to improve the joint between mutually adjacent floor component i the illustrated application, however, the tongue and groove joint is effected by means of tongues and grooves which form angles of substantially 90° with the plane of associa- ted boards. To this end, a groove is provided along each of the side members 1 and 2 on one side of the structural member, said grooves both facing in mutually the same direction, while mutually oppositely directed tongues are provided along the other side of the structural member. This enables one floor component according to the invention to be readily hooked firmly to an adjacent floor component, in the manner illustrated, thereby stiffening the floor

structure as a whole and eliminating the possible presence of seasoning cracks between the floor components. This together with the latching effect on the wood in the side- members 1 and 2 afforded by the distance pieces 3 enables a floor to be constructed from structural components accor¬ ding to the invention with which there is a minimum risk of crack formation or movements between the individual boards.

In order to further improve the joint between mutually adjacent floor components and the rigidity of the transi- tion region, an elongated strip-like element 5, for example a wood-fibre strip, can be inserted in slots 6 in the side edges of the distance pieces 3, as illustrated in Figs. 1 and 2. In order to improve the stiffening effect of the strip-like elements 5 and to facilitate laying of the floor components, the top and bottom side members 1 and 2 of the illustrated embodiment are displaced laterally in relation to one another. This is not an essential feature of the invention, however, and elements of purely elongated rectangu lar cross-section can be manufactured. The use of inclined components, however, improves among other -things the seal between mutually adjacent, foam-filled components.

Fig. 3 illustrates an alternative method of producing a stiffening joint between mutually adjacent floor components this-alternative method simplifying manufacture of the floor components and the laying thereof. Instead of the obliquely fitted strip-like element of Figs. 1 and 2 there is used in the Fig. 3 embodiment horizontal, suitably slightly wedge- shaped elements 20, which can be inserted from one end of each floor component into a horizontal groove 21 extending along one longitudinal side of the floor component. The groove 21 has a wedge-shaped cross-section corresponding to that of the strip-like element 20, but slightly larger dimensions than said element. The reference 22 identifies a wedge-shaped groove which corresponds to the strip-like element 20 and which extends along the other longitudinal side of each floor component, and the reference 23 identi¬ fies a plurality of transverse holes disposed along the length of said element.

In this embodiment mutually adjacent floor components can be joined together by pressing the strip-like element carried by one floor component into a corresponding groove 22 located in an adjacent floor component, with the aid of a lever or some other suitable tool. The strip-like element 20 will therewith tightly conform to the defining surfaces of the grooves 21 and 22.

Because the boards are effectively held together in correct positions relative to one another with the aid of the distance pieces 3, a structural component according to the invention can be produced in a continuous process. A method and a machine herefor will now be described with reference to Fig. 4. The machine illustrated schematically therein is intended for the manufacture of structural co - ponents of purely elongated rectangular cross-section, for example for wall structures, but can be readily modified for manufacturing the structural components illustrated in Figs. 1 and 2.

When practising the embodiment of the invention illustrated in Fig. 4, the two side-members 1 and 2 of the structural component are guided into a station 7 by means of rollers 8, which are driven by a motor 9. Distance pieces 3 are positioned between the incoming pair of side- members 1 ^" and 2 in the station 7, with the aid of an end- less belt 10 having supports 11 for supporting the distance pieces 3, which are fed from a magazine 12. When braces 4 are required, these braces are placed between the distance elements 3 in the station 7. The means required for positio¬ ning the distance pieces 3 and the braces 4 can be of any desired construction. The only necessity in this respect is to ensure that the distance pieces 3 are held correctly in position between the side-members 1 and 2 when the side- members are pressed towards one another by means of the illustrated outer rollers 13, as the side-members leave the station 7.

The projections on the distance pieces 3 intended for engagement with respective grooves in the side-members 1

and 2 are coated with glue prior to positioning the dis¬ tance pieces between the side-members, which are firmly fixed relative to one another immediately they are pressed into engagement with the distance pieces, inter alia as a result of the friction between projections and grooves. Among other things it is this which enables the struc¬ tural component to be manufactured in a continuous process, since said component need not be held under pressure in a stationary press device. The individual boards forming the side-members can be joined end to end with one another as they are held fixed relative to one another by the tongue and groove joint between the two boards of each side-member, and by the distance pieces 3. Because the structural component accord- ing to the invention can be manufactured in a continuous running length, unnecessary wastage is avoided both when manufacturing the structural component, since whole board lengths can be used, and in the latter use of said com¬ ponent, since components of suitable lengths for the use in question can be pre-cut from a single long length.

The design of the structural component also enables it to be readily filled with insulating foam in conjunction with the manufacture of the component. To this end there is arranged a foam-filling nozzle 14 at that position in the machine where the side-members 1 and 2 are pressed in¬ to engagement with the distance pieces 3. Foaming of the insulating substance takes place in the cavity presented between the side-members 1 and 2 and divided into separate compartments by the distance pieces 3. The pressure in the cavity increases considerably during foaming of the insula¬ tion, and is taken up laterally by the rollers 13. The normally open sides of the structural component are held closed along that part of the machine at which foaming takes place, by means of an upper and a lower endless steel belt 15 and 16, which accompanies the movement of the structural component and is pressed sealingly against

the side edges of the side-members 1 and 2 thereof. To this end there are used on the. rear sides of the belts 5 counter- pressure devices (not shown) having a low-friction slide surface facing towards respective belts. The ease with which the structural component can be filled with foam is due to the distance pieces 3, which function as throttles. Without the presence of sealing distance pieces, the foam mass would be pressed out of the cavity in a direction towards the station 7. The distance pieces 3, however, form together with the belts 15 and 16 and the side-members 1 and 2 closed chambers which enclose the foam.

The fact that the structural component can be filled with foam during the process of manufacturing the component affords several advantages, among which can be included a significantly more effective and more readily controlled filling of the component with foam and more rational con¬ struction, .since it is no longer- necessary to fill the structural component with foam insulation in a separate working stage on the working site. In addition hereto, a foam-filled structural component according to the invention is completely straight, and will not subsequently change shape as a result, inter alia, of the barrier action of the foam. The aforedescribed machine can be modified in various respects within the scope of the following claims, while retaining the advantages of continuous and rational manu¬ facture of a structural component, with simultaneous filling of the component with foam insulation. This applies, for example, to both the station 7 for mounting the distance pieces, and the arrangement for sealing the aforesaid cavity when filling the compartmental cavities between the distance pieces with foam.