| 1. | An arrangement for joining two articles to each other along a joint and/or for sealing two articles with regard to each other, c h a r a c t e r i s e d in that the arrangement comprises a first member (1) consisting of resilient material and a second member (2) withstanding the environment and retaining said first member (1) prestressed, said first member (1) being retained prestressed during its entire period of storage before utilization and said second member (2) being made to give at a desired moment by being subjected to a temperature change which is greater than the one occuring in the environment during the period of storage or by mechanical actuation for releasing the prestress of the first member (1). |
| 2. | An arrangement in accordance with Claim 1, c h a r a c t e r i s e d in that the second member is a thermoplastic mass. |
| 3. | An arrangement in accordance with Claim 2, c h a r a c t e r i s e d in that prestress of the first member (1) is released by heating the second member (2) by means of an internal or external heat source. |
| 4. | An arrangement in accordance with Claim 3, c h a r a c t e r i s e d in that the second member (2) is heated by means of an electric current flowing through a conductor (7) which extends along the two members (1, 2) and which for example is moulded into the second member (2) or is disposed in a groove in the first member. |
| 5. | An arrangement in accordance with Claim 3, c h a r a c t e r i s e d in that the second member is electrically conductive and that heating is carried out by means of high frequency current. |
| 6. | An arrangement in accordance with Claim 1, c h a r a c t e r i s e d in that the second member is comprised of metal (for example lead rods) and has a melting point which is lower than the melting point of the material of the first member (for example spring steel). |
| 7. | An arrangement in accordance with Claim 1, c h a r a c t e r i s e d in that the second member consists of a casing, for example in the form of a pipe or tube, filled with sealing mass. |
| 8. | An arrangement in accordance with Claim 7, c h a r a c t e r i s e d in that the casing is made to collapse by means of mechanical actuation, with the prestress of the first member being released and the articles being secured simultaneously with the sealing mass being urged into the joint and being brought into contact with the environment for curing the mass. |
| 9. | An arrangement in accordance with Claim 8, c h a r a c t e r i s e d in that the casing is made to collapse by an electric current flowing through a conductor located in said casing. |
| 10. | An arrangement in accordance with Claim 8, c h a r a c t e r i s e d in that the casing is made to collapse by high frequency heating. |
| 11. | An arrangement in accordance with any one of Claims 17, c h a r a c t e r i s e d in that the quantity of thermoplastic material is chosen such, that when the prestress of the first member is released said material fills the joint completely and functions as a sealing mass. |
| 12. | An arrangement in accordance with any one of Claims 111, c h a r a c t e r i s e d in that the first member is slitted and is provided with a rubber profile, whereby the first member also can be applied to curved joints. |
The present invention concerns an arrangement for joining two articles to each other and/or for sealing two articles with regard to each other..
When two articles are to be joined to each other and/or two articles are to be sealed with regard to each other different methods may be used. For joining two plates it is for example possible to make use of edge folding, and if sealing is to be carried out simultaneously a strand of sealing material may be introduced into the fold. Another possibility is to make use of rivet joints with gaskets, and an additional alternative is to utilize screw joints with gaskets. Furthermore, joining can be carried out by means of guides which are slid onto two flat articles and secure the latter to each other by means of protrusions. This method is common for joining ventilating drums having square or rectangular cross sections. An additional alternative is to make use of a weld joint, including a spot weld joint. The present invention has for its purpose to disclose an arrangement which to advantage may be used for joining and/or sealing all of the above-mentioned types with good economy and simple handling.
The means by which the object set out by the invention are achieved are disclosed in the accompanying claims.
The invention will be described in detail below with reference to the accompanying drawings, in which Figures 1-3 show examples of joining and simultaneous sealing in accordance with the invention, Figures 4-9 show examples of how solely sealing can be provided in accordance with the invention, and Figures 10 and 11 show examples of solely joining in accordance with the invention. The same reference numerals have been utilized in the different figures wherever possible.
An embodiment of the arrangement disclosed by the invention for sealing and joining is shown in Figure 1, in which the arrangement comprises a profile 1 composed of resilient material, such as spring steel, said profile preferably being in the form of a strip, -furthermore a * thermoplastic sealing mass 2 which is located in said profile, which latter may be substantially U-shaped, and a product which is to be sealed and joined, for example two plates 3 and 4 having flanges 5 and 6 which are to abut each other. The hardness of the sealing mass 2 at storage temperatures is such, that it can maintain profile 1 in its outwardly urged position. When the product is to be used the sealing mass 2 is heated so that it becomes plastic, whereby the profile "shrinks" to its quiescent position which is illustrated in Figure 2. The change of form of the profile is utilized on one hand for urging the two articles 3, 5 and 4, 6, respectively, together and on the other hand for urging the thermoplastic mass 2 into the joint between the articles in consequence of the sectional area of profile 1 decreasing.
Heating can be carried out with an external source of heat such as an open flame or "hot air or with an electric current which flows through a conductor 7 which has been introduced into the profile (Figures 1 and 2) or which has been moulded into the sealing mass (Figure 3).
In heating with an electric current a current source is used with an electronic control which measures the resist¬ ance of the conductor when it is first connected, adapts the current to a predetermined value, and cuts off the current when the resistance of the conductor has increased to a value corresponding to an appropriate temperature.
Figure 3 more specifically illustrates an alternative in which the profile 8 has been made flexible so that it may function even if the articles are of curved shape. If a "strip section" is cut at the indications 9 and 10 and is removed and if a rubber profile 11 is cut out at 12 (Figure 3) the strip may be bent over a corner at an angle of for example 90°.
Generally speaking, the quantity of thermoplastic mass is not particularly critical, and the method can also be utilized for solely providing sealing between articles which already are secured. In the latter case the resilient qualities of the profile are less critical. Such sealing can also occur in water. The profile can be included a3 part of one of the articles which are to be joined. It is also possible to replace the thermoplastic mass with a hard casing which can urge the profile outwards. In the casing for example silicone rubber that can be hardened in air may be included. In use the casing is made to collapse, whereby the profile shrinks, securing occurs and the silicone rubber is urged into the joint at the same time as it contacts the air and hardens. The casing can for example consist of toughened glass which collapses completely as a result of being damaged at one point. A second method is to utilize a glass tube with an electric conductor melted into it. When current passes through the electric conductor the glass tube is heated, which creates such internal tension in the glass tube that it collapses. In applying the invention it is necessary to give consideration to certain things in connection with embodying the profile, namely that it is to have
sufficient resiliency for secure joining, sufficient elasticity for being able to flex outwardly and to be stored in prestressed position without losing its resiliency, it is to have an appropriate cross section (shape) so a3 that the cross sectional area will be changed sufficiently for the sealing mass to be urged into the joint, it is to have an appropriate form so that it will grip the articles securely, and it is to be corrosion proof. Certain requirements are set for the thermoplastic material. Thus,- it must have a low melting temperature, an appropriate viscosity at different temperatures, storage capacity, cold and heat resistance, adherence characteristics and resiliency so as to be " able to withstand and permit, respectively, movements of the articles or of the profile and the articles.
The design of the electric conductor is to be satisfactory with respect to dimensioning, choice of material, centering in the profile, mains connection and technology in cutting the profile.
In applying the invention various accessories and tools may be used, and these are of importance already in the manufacturing and the general handling as well as in storing, cutting, any plugging when heating, mains connection and electric equipment (automaticity) .
Practical tests have been made with a short profile which interconnects two pieces of metal sheeting. The • thermoplastic mass used at that time was "Bostic Thermagrip Melting Adhesive Intended for Adhesive Gun 2000". As the source of current a soldering gun was used. The results were positive.
The invention may to advantage be utilized for providing a seal. Thus, Figure 4 shows a seal which in the- illustrated example is round and is made of foam material 13 with closed pores. Around the gasket there is a layer 14 of thermoplastic mass which is applied as a tube. In storage the tube is so strong that it keeps gasket 13
compressed. In use the arrangement is placed in a joint which is to be sealed, for example between blocks 15 and 16. Thereafter the arrangement is heated by means of an external heat source or an electric current whereby the thermoplastic mass 14 will soften, the arrangement will expand, and sealing and "adhesion" will occur as shown in Figure 5. The gasket shown in Figures 4 and 5 can be replaced by a "reversed" one according to Figures 6 and 7, i.e. with a thermoplastic strand 17 as a core and a compressed gasket 18 as a casing. As the result of the thermoplastic strand being heated, for example by an electric conductor 19 disposed therein, the gasket 18 will expand, with the final result being as shown in Figure 7. When the state illustrated by Figure 7 has been achieved the thermoplastic material 17 will have no function, as when this material is heated by means of a current through electric conductor 19 the compressed tube gasket 18 will release the core consisting of.thermoplastic material 17, in addition to which it will expand and sealing will occur.
An alternative to the embodiment of Figures 6 and 7 is shown in Figures 8 and 9, wherein the arrangement comprises a strand 20 of melting adhesive which is surrounded by a gasket 21. When current flows through an electric conductor 22 the adhesive melts, with melt adhesive residue remaining around the electric conductor 22, whereas gasket 21 expands to a round ring as illustrated in Figure 9.
An additional alternative is to utilize expanding gasket material consisting of foam material with internal cells coated with melting adhesive. If the material is compressed while being heated and is cooled before the compression force is removed a gasket which expands when heated is formed. In this case, too, heating can be performed by means of an external heat source, for example hot air, or by means of an electric current flowing through internal conductors or by means of high frequency
current if the gasket has electrically conductive characteristics.
The material as outlined above may also be used for reducing the volume of porous materials in storage and shipping.
Still another field of use for the arrangement according to the invention is for example for mounting door and window frames in housing structures. Expanding profiles having an engagement function may be utilized in this connection. This is illustrated in Figures 10 and 11. In the joint between the frame 23 and the wall 24 a profile 26 affixed by melt adhesive 25 according to Figure 10 is introduced. The profile is heated, the adhesive softens, the profile expands and the frame is secured according to Figure 11, in which the designation 27 refers to adhesive residue. If desired a profile may be slitted in order to provide better engagement.
In summary it may be said that the invention can be used for joining components so as to provide straight joints, for example roof plates and housing plates, angled joints, such as in rectangular ventilating drums, or curved joints, for example in round ventilating drums, or alternatively the profile may for example take the form of an unbroken ring for joining and/or sealing pipe flanges or the like. Furthermore, combined joints can occur, for example mounting roof plates or housing plates and concurrent securing to a building structure, securing insulation, and/or joining plates. A possible area of utilization is also sealing joints in water. The invention is not restricted to the embodiments described above and illustrated in the drawings, and a multiplicity of such can exist, as is indicated by the examples given above. Thus, the material in a first member of the arrangement can consist of for example spring steel, whereas the second member may be comprised of metal, for example lead rods, having a lower melting point than the melting point of the spring steel.