GB2076498A - Joining Wooden Boards etc. with Plate Profile Members - Google Patents

Abstract

A method of joining wooden boards and the like with open or closed plate profiles to various constructions, especially for outdoor use, of the type fence, garden furniture, bridges and the like. The method of the invention is characterized by the following operations. A plate strip of a plane material is first provided with punched holes (2) in the boards, the holes being arranged in pairs, two for each board. The plate strip with holes is thereafter pressed or rolled to its final profile (3), the punched out holes (2) forming guides of boards or bars, the retaining edges (3a) or the like (lugs or points) cooperating with the edge or lateral surfaces of the boards. Before the boards or bars are inserted into the holes they are dried to a moisture content which is as far as possible below the moisture content arising in the working environment of the device, preferably outdoors. After inserting the boards in the guide holes the moisture content is increased so that the boards swell and are pressed against the edges of the guide holes. <IMAGE>

Description

SPECIFICATION A Method and a Device for Joining Wooden Boards etc. with Plate Profiles This invention relates to a method of providing a self-supporting metal wood construction, especially intended for outdoor use, e.g. at fences, garden furniture, bridges, pallets etc., where boards or wooden bars are joined to each other by means of lists or metal profiles, where the boards or wooden bars are passed through metal profiles perpendicularly or substantially perpendicularly, which enclose the boards or bars on all sides.

It is the object of the method of the invention to provide a very sturdy construction, where the boards and metal profiles are protected from cracking, warping or coming loose without nail or screw joints being necessary.

It is well-known that screwed or nailed wooden elements have a tendency to cracking exactly where the nail or screw passes the board. This is a se ious di advantage at many constructions, e.g.

pallets, fences, building elements, garden furniture, duckboards, etc. Above all this applies to constructions where boards are adapted with interspaces (slits) and are exposed to weather strains and and changes in temperature, variations in humidity and possibly also shocks.

All such phenomena contribute to warping of the boards, their shrinkage and swelling, and they will crack and come loose due to this.

The method of the invention is substantially characterized in that plate strips of a plane metal material is provided in a first operation with holes punched out in pairs, two for each bar or board, the edges of the holes being made as retaining elements in the form of points or lugs intended to increase the contact pressure between the hole edges and the inserted bars or boards, after which the plate strip is pressed or rolled to a supporting (stiff) profile, where the holes punched out in pairs will lie substantially straight opposite to each other, so that they form a guide for the bar or board which is then to be brought through the holes, the bars or boards being subjected to a drying operation before being moved through the holes so that the moisture content of the bars or boards is reduced to a level being as much as possible below the moisture content normally occuring in use of the product, especially outdoors, the boards or bars allowing a certain angular or lengthwise adjustment after being passed through but being moistened when arranged on a final place (fence) or in final environment (garden furniture etc.) so that the woodwork will swell and fix the elements of the construction to a stiff joint.

A number of embodiments of the invention and a construction for carrying out the method of the invention will be described below with reference to the enclosed drawings. In these Fig. 1 shows a simple embodiment of a plate element intended to be joined to a board with a groove according to Fig. 2. Fig. 3 shows a section of an intermediate member or pole made from a profile according to the invention with a passing lying or upright board. Fig. 4 shows a corresponding view of another embodiment with milled grooves in the boards for both the upper and the lower profile flanges. This embodiment is especially well suited for duckboards and the like. Fig. 5 shows an edge joint according to the invention and Fig. 6 the same corner with the parts assembled.Fig. 7 shows a side view of the plate profile in this edge joint with holes for two adjacent boards and a resilient retaining means for these, especially suitable for garden furniture. Fig. 8 shows an end view of a supporting intermediate member consisting of two metal profiles supporting two upright parallel paling boards. Fig. 9 shows on a smaller scale the use of this construction on a windshield as seen from above according to the invention. Fig. 10 shows an embodiment of the invention in the form of a method of attachment, which might also be used by the customer, intended for fences that can be inclined on sloping ground. Figs. 11 and 1 a show this construction from above as an example of how such a construction with a fixed attachment of the board element is carried out by means of lugs in the plate profile.Fig. 1 2 shows a garden chair joined according to Figs. 5, 6 and 7 according to the invention and Fig. 1 3 shows a corresponding table. Fig. 14 shows a use of the method of attachment according to the invention at tongued and grooved timber forming boardings or similar building elements. Fig. 1 5 shows an end view of the same construction. Fig. 1 6 shows a plane view of a boarding thus joined. Figs. 1 7-20 show elements in a machine for joining devices according to the invention, e.g. for packings, fences, building constructions etc.

In Fig. 1 the method is shown as used when joining two perpendicular elements. A plate strip 1 is provided with punched out holes 2 for boards 5, after which a suitable profile of the plate strip 1 is bent, as is apparent from Fig. 1. A plate having a thickness of 0.5-3.0 mm depending on the use is then preferably used, and the plate should be galvanized above all for outdoor use. This joining method with a thicker plate is well suited for strong resting furniture, bridges etc.

The boards 5 according to Fig. 2 can preferably be provided with grooves 4 on their upper side, as is shown in the figure, so that the upper portion 1 of the plate profile can fall down or be pressed down to the groove 4 at mounting of the products. Of course the boards 5 can be pressed without any grooves, the board section being pressed together so much, after inserting the boards in the holes, that the flanges 3 of the profile are upset or bent between the holes. Due to this the lower edges 3a of the profile will be somewhat forced up in the underside of the board and lock this. In many cases it can be suitable to punch one or more lugs or stubs 10 when punching the plate strip, as is shown in Figs. 10 and 11, these stubs possibly being pressed into the board afterwards.This can be done by means of machines or by inserting a wooden rib below the boards, as is apparent from Figs. 3 and 8, 14.

The method of pushing in a rib or a spring element, see Fig. 7, under the boards, so that these are pressed upwards against the upper side of the profile, which is then pressed up or down into the grooves of the boards, will make it possible to deliver boards and profiles each by themselves, after which the customer will mount the product. This is especially suitable for outdoor panels, garden furniture, fences and the like, where the product is exposed to great changes in temperature. The punched out lugs can also be used to attach the boards in such a way that they are hammered into the board by means of some hammer strokes, the stubs replacing the grooves in the boards.

At constructions which are to be used in such a way that the board can be turned into the profile hole for inclination, e.g. at fences on sloping ground, it is more suitable to use the compression method so that the woodwork is compressed to bend the flanges 3 between the punched out holes. In this way a tension or resilience in the flanges is obtained which will always secure the boards even it these dry somewhat under the influence of e.g. indoor temperatures. This compression can also be carried out after mounting on the products described above and is preferably made with one single stroke in such a press as described below in connection with Figs.

17-20. Such a compressed board section will provide a very strong joint which is very rigid.

If a fiat joint is desired so that the plate profile does not get outside the boards neither on the upper nor the underside, grooves can also be milled on the underside of the boards, into which the lower flanges or edges of the profile can sink at compression, see Fig. 4. This procedure is especially suitable in manufacture of e.g.

duckboards, which are very strong in this way and insensitive to moisture as compared with nailed duckboards, which are apt to crack or warp, especially as the thin boards of the duckboards as a rule are nailed from below.

In manufacture of garden furniture according to the method of the invention the boards are inserted into holes in a plate profile which prevents the boards from cracking, warping or coming loose. Fig. 5. 6 and 7 show this special and very good method especially well suited for constructions where there are great strains.

Garden furniture is subjected in a larger degree than other constructions to great changes in temperature and humidity and at winter storage frost strains are added. Maltreated garden furniture which is not protected during the winter has therefore often a very short life.

When the invention is utilized in this way it is intended that the customer should mount the parts himself, which makes possible a cheaper product, above all regarding packing and transport costs.

Thus, by the method of the invention a very strong furniture, e.g. a table, a sofa and two armchairs with high backs made from a tough wood 1 9x95 mm can be packed in a cardboard box, which is only 40 cm wide, 22 cm high and 1.6 m long.

In this case boards with roughly sawed ends (planing of boards is a cheap operation as compared with trimming of visible end surfaces) provided with a small saw notch about 10 mm from the end of the board are used (see Fig. 5), after which these are inserted into the closed side profiles (Fig. 6 and 7). The resilient underlying members are then knocked in under the boards so that the edges 6 of the profiles enter the saw notches of the boards. In this simple way all furniture parts have been obtained which are then screwed together in usual manner. The resilient underlying members of steel (Fig. 7) will then press the boards upwards towards the upper edges of the profiles for the whole time irrespective of the fact how much the boards dry up or swell.

At construction of fences and wind shields, Figs. 3, 8, 9, 10 and 11, these are assembled in the way described above. Joining of the sections can be carried out in various manners. One method is having the ribs 7, 8 and 11 project on one side, after which the sections are pushed together in mounting. It is then possible to use round iron cotters, which are driven into holes 9, both for jointing and for attachment in end and intermediate posts.

The method of the invention will also give a possibility of providing e.g. fences with lath decorations as well as a possibility of placing them inclined on sloping ground, see Figs. 10, 11 and 11 a. As already described above the board is then pressed or knocked against the stubs 10 in the plate profile or the stubs 10 in the plate profile or the stubs 10 in the board, Fig. 11 a, and as these stubs are approximately at the center of the laths, it is easy to turn the lath in the holes. If the ground is extraordinarily sloping extra wide holes are punched out in the plate profile. Inclining the fence sections is carried out in such a way that the section is held vertically and one end of the plate profile is knocked against a stone or the like until the desired inclination of the section is obtained.

Plate decorations can be obtained on the upper side by designing the hole punches according to a desired decoration line so that the material of the decoration is taken from the holes.

According to the present invention completely tight board sections (wooden paling) can also be made, see Figs. 14, 15 and 1 6. Completely tight building sections, e.g. palings, duckboard decks, boxes, packing flaps and similar products can also be achieved by plate profiles having side holes for the boards. E.g. two boards (13,14) are then inserted into the same hole. The board 13 which has been provided with small saw notches 12 for the flanges 3 is first inserted, after which this board is pushed to the left in the figure so that the flanges 3 fall down into the saw notch 12 of the board. The other board 14 is then inserted. It is now possible to push in the ribs 11 in order to press together the section, if desired, in the same way as described below in connections with Figs.

17-20.

In Figs. 1 7-20 a semiautomatic mounting press for board sections of the type shown in Figs.

1-1 6 is illustrated. The press device for carrying out the method of the invention has a working cycle which takes about 1 2 seconds for simple board sections (duckboards and the like) in the prototype example, and as the press is provided with a table which can take two duckboards at a time about 20.duckboards per minute can be mounted and pressed together. Exchange of the wood stock 1 7 must be added, and therefore the press will effectively produce 7-8 duckboards per minute or 3-4 other board sections without underlying ribs 7 up to 2x2 mm, which is the greatest press surface of this press. For mounting underlying ribs 7, Fig. 17, about 3 seconds must be added, and the press will then produce 3 such board sections per minute.

Completely tight sections require additional feeding rate for boards 13 and therefore the effective working capacity will be about two such sections per minute. It is possible to increase the length of the boards and the corresponding lengths 1 7 and 30 of the wood stocks to wall heights of about 2.5 m, and such sections are then discharged transversely in the press by means of the hydraulic feeding cylinder 22.

The press of the invention is operated by hydraulic cylinders which are fed by a hydraulic pump unit of known type and placed on the right side of wood stock 1 7 in the figure. The press is provided with three feeding cylinders 20 having double cylinder rods so that they can feed the plate profiles 28 and simultaneously push out the finished section and at returning pull in the underlying ribs 7, 18.

The press has also a feeding cylinder 22 for the boards 29 which is provided with a feeding ramp having adjustable feeding hooks 23 for each type of boards. When these are fed into the press they are guided by guide flutes 1 9.

The press 1 5 is provided with four press cylinders 26, which each exert a pressure force of 25 tons, which at return gives the press a total press pressure of about 200 tons. The cylinders function here as press pillars. The press has two underlying H-beams 25 and two similar overhead H-beams 24. Between these six press beams 27 are placed, which are laterally displaceable. (It is also possible to carry out feeding of the underlying wooden ribs 18 by means of feeding cylinders 21 of their own).

The press is operated by two persons, one placing the plate profiles in the plate store 16. He also manages the operating valves of the press.

The other person receives the finished sections and stacks these by means of a special lifting device. The capacity of the wood stock is about 50 boards in height, which is enough for an operation of about 10 and 30 minutes. The store 1 7 has four wheels and is exchanged for a full store in a couple of minutes. The wood stock 18 for the wooden ribs is fed manually by the same person working on that side.

Claims (2)

Claims

1. A method of providing a self-supporting metal/wood construction especially intended for outdoor use, e.g. at fences, garden furniture, bridges, pallets, etc, where boards or wooden bars are joined to each other with metal lists or profiles, where the boards or wooden bars are passed through holes in metal profiles perpendicularly or substantially perpendicularly, which enclose the boards or bars on all sides, characterized in that plate strips of a plane metal material are provided in a first operation with holes punched in pairs, two for each bar or board, the edges of the holes being shaped as retaining elements in the form of points or lugs intended to increase the contact pressure between the hole edges and the inserted bars or boards, after which the plate strip is pressed or rolled to a supporting (stiff) profile, where the holes punched out in pairs will lie substantially straight opposite to each other so that they form a guide for the bar or board which is then to be passed through the two holes, the bars or boards being subjected to a drying operation before being brought through the holes so that the moisture content of the bars or boards is reduced to a level being as much as possible below the moisture content normally occuring in use of the product, especially outdoors, the boards or bars allowing a certain angular or lengthwise adjustment immediately after being passed through, but being moistened when arranged on a final place (fence or the like) or in final environment (garden furniture, bridges etc.) so that the woodwork is caused to swell and in this way fix the elements of the construction to a stiff joint.

2. A method of joining wooden boards and plate profiles substantially as described herein with reference to any Figure of the accompanying drawings.