EP0017291B1

EP0017291B1 - Fastener

Info

Publication number: EP0017291B1
Application number: EP80200281A
Authority: EP
Inventors: Michel Bouckaert
Original assignee: BOELWERF NV
Current assignee: BOELWERF NV
Priority date: 1979-03-29
Filing date: 1980-03-27
Publication date: 1983-08-31
Also published as: EP0017291A1; DE3064678D1

Description

This invention relates to a fastener for fastening an insulating panel to a wall, comprising a body adapted to fit into a hole of the panel, a collar on a first axial end of the body for pressing against the panel, a coaxial central opening adapted to receive a pin, and a coaxial recess from the first end of the body adapted to accommodate a nut on the pin for pressing against a shoulder of the recess, the central opening extending between the second axial end of the body and the shoulder.
Usually insulating panels are glued against the walls to be insulated. Due to the narrow spaces usually available, this is difficult to perform and also particularly unhealthy due to the emanations and vapours which are released by such work. Moreover difficulties are encountered when arranging large panels because relatively small deviations result in problems when joining said panels.
The invention has not only for an object to obviate the above drawbacks but also to provide an original solution to the following problems:

1. avoiding glueing of insulating panels and using smoke developing materials in narrow spaces such as those existing between a ship hull and a tankwall to be insulated.
2. providing an insulation with sufficient mechanical strength to allow walking on the top surface of said insulating material, whereby further the material should be water-proof at the bottom thereof;
3. said insulation material having to be generally vapour-proof;
4. the insulation layer having to be mounted in very narrow places and actually by unskilled workers;
5. avoiding the use of dangerous materials or materials which are difficult to use;
- It is to be noted that in a ship the holds or tanks of which are to be insulated, said insulation is arranged on the bottom walls before lowering the tank bottom walls on the supports thereof. When said tanks have been positioned, the finishing and touching-up of said tanks is very difficult and laborious.

In German patent application 2.757.903 it has already been proposed to press insulating panels against a flat surface by making use of fastening means having a cylindrical body, a collar pressing against the insulating panel and a bottom to be screwed on pins which are themselves screwed through the surface to be insulated.
With such fastening means it will not be possible to apply a method as set forth below because any discrepancy between the spacing of the pins welded on the outer tankwall and the spacing of the holes of the insulating panels will result in the impossibility of adjusting the fasteners correctly in the holes of the panels and in having the fasteners screwed on said pins. A new fastener is proposed which allows the insulating panels to be easy mounted and pressed against a tankwall to be insulated, even when these panels have their holes not exactly fitting with the pins welded on the tankwall.
To this end the outer surface of the body of said fastener is conical and the central opening contains a conical portion, the width of the central opening being substantially greater at the second end of the body than at the shoulder of same.
Other details and features of the invention will stand out from the following description given by way of non limitative example and with reference to the accompanying drawings, in which:

Figure 1 is a bottom view with parts broken away, of the insulated bottom wall from a tank.
Figure 2 is a cross-section drawn on another scale.

In both figures, the same reference numerals pertain to similar elements.
To better understand the properties of the fastener according to the invention a method making use of same will be illustrated by the attached drawings. According to these drawings reference 1 is the bottom wall of a tank 2 to be insulated. It is clear that the vertical walls of a tank will be treated in the same way.
The top side or roof of a tank can be finished according to the same method or according to a more conventional method, depending on the particular conditions.
With the method incorporating the fasteners according to the invention, a number of pins 3 are welded to wall 1. Said pins which are regularly spaced, are made from stainless steel and the heads 3' thereof are provided with screw thread. Over each set of four pins 3 an insulating panel 4 is pushed. The insulating panels 4 (fig. 2) are comprised of an insulating self-extinguishing foam layer 5 and are finished on the outer side with an aluminium sheet 6. Said insulating panels thus have a number of openings 7 which are distributed over the panel surface area according to a module which corresponds to the module according to which said pins 3 are distributed over the tank wall.
To press said insulating panels 4 against tank wall 1, fasteners 8 are pushed over pins 3 in said openings 7. Said fasteners 8 are retained pressed against tank wall 1 by screwing self- locking nuts 3" on the heads 3' of pins 3.
For this purpose said fasteners 8 have a collar 9 which is retained pressed against resilient sealing rings 10. The space above head 3' of pins 3 is sealed with a plug 11 and a cover 12.
Said fasteners 8 provided with an inner centering ring 8', are made of a synthetic or plastic material, preferably polyethylene.
When using panels according to the invention, there is formed between the edges of two adjacent panels, a space which is filled with an injectable foam. The injected foam which fills said space is shown in 13. To bound that space to be filled with foam, the following operations are performed.

1. On the wall of an insulating panel, a strip 14 of foam material is arranged, preferably by nailing. Said strip connects tightly to said tank wall, is slightly compressed under the action of injected foam 13 and prevents any further flowing out of said foam between the'tank wall and panel.
2. Along the outer side thereof the edges of panels lying next to one another are provided with adhesive tapes 15 and 16. Said adhesive tapes intersect at right angle to one another and thus determine together with the side walls of panels 4 and said strips 14, that space which will be filled by the injected foam 13. The injection occurs without difficulty through said adhesive tapes 15 and 16, whereby the complete space between the panels can be filled systematically with an hardenable foam which is naturally self-extinguishing. The small holes formed are sealed with small self-adhesive strips 17. By using insulating panels according to the invention, there are formed between the walls thereof spaces which can be filled and integrally insulated. The insulation of said spaces then forms a continuous and homogeneous unit with the insulating panels proper. The spaces between the insulating panels proper do not have to be regular, they easily compensate for any irregularity in the panel size. There appears from the above description that it is no more to be feared as it was the case up to now, that discrepancies in the size of the insulating panels or in the arrangement thereof might have an adverse influence on the dimensions of the insulated surfaces areas proper, which caused large problems when insulating tank walls, mostly where lack of space did make it extremely difficult to finish according to the conventional techniques. The expansion of the hardenable foam can occur in those spaces determined by said adhesive tapes and be tested with the hand from the outside. An excess of foaming material will be received by the resilient strips from foam material, as an open-cell material is preferred therefor. Due to the presence of said foam strips, entering of foam between the tank wall and the panels to be insulated is also prevented, which would otherwise bring the danger of the panels being pushed away from the walls.

By selecting a hardenable foam which adheres well to the form from the insulating panels, the above-mentioned homogeneity of the insulating layer is insured.
Finally it should be stressed that contraction movements of the tank skin are accepted by the material the resilient strips are made of and that the fasteners 8 can receive side forces from the panel and transfer same to the pins without endangering the isolating material 5 the panels 4 are made of.
It must be understood that the invention is in no way limited to the above embodiments and that many changes can be brought therein without departing from the scope of the invention as defined in the appended claims.

Claims

1. Fastener for fastening an insulating panel (4) to a wall (1), comprising a body (8) adapted to fit into a hole (7) of the panel (4), a collar (9) on a first axial end of the body (8) for pressing against the panel (4), a coaxial central opening adapted to receive a pin (3), and a coaxial recess from the first end of the body (8) adapted to accommodate a nut (3") on the pin (3) for pressing against a shoulder of the recess, the central opening extending between the second axial end of the body (8) and the shoulder, characterised in that the outer surface of the body (8) is conical and that the central opening contains a conical portion (8'), the width of the central opening being substantially greater at the second end of the body (8) than at the shoulder.

2. Fastener according to claim 1, characterized in that it is made of synthetic material.

3. Fastener according to claim 1, characterized in that said synthetic material is polyethylene.