FASTENING MEANS AND METHOD FOR THE USE WITH POROUS MATERIALS

Abstract: Fastening means for fastening in more or less porous, granulous or else penetratable materials constituted by two elements, a first (1) consisting in general of a plate (1) provided with a slot (2) with an initial path extending straight into material and plate passing into an inner curved or bent part. The plate is first inserted into the material in question. Thereafter a strip (3) of metal is pushed into the material and the slot (2) in the plate (1). The strip will follow the slot and thus grip into and around a part of the material. The friction between strip and material keeps the strip in position and considerable force can now be taken by the plate also in the direction of its insertion.

Description: FASTENING MEANS AND METHOD FOR THE USE WITH POROUS MATERIALS This invention concerns method and means for fastening in porous materials as for instance cell plastic. (The term porous materials is hear meant in a broad sence, covering also granulous and other easi¬ ly penetratable materials.) Cell plastic materials as well as other porous materials have very good heat insulating properties and they have therefore been more and more used in the t ilding technique. Pure sandwich constructions with a core of polyurethane cell plastic between two metal sheets are of great impor¬ tance in connection with industry buildings. Construe- tions of this type, below called panels, have in par¬ ticular with great success been used all over the world for freezing chambers, cold-storage rooms and cold-storage warehouses in the two latest decades. Mostly the panels are provided with groove and tenon and appropriate seals. In buildings for freeze storage an unyieldable requirement is that the joint between the panels is sealed against diffusion. This is achieved by locking the panels together with a locking device giving a permanent compression of the sealing strips and thus a permanent sealing func¬ tion. The locking device usually consists of two halves that have been placed centrically in the cell plastic core close to the edges of the panel. The placing demands great accuracy in order to secure on mounting that the lockhalves in adjacent panels have exactly coinciding positions. A small deviation means a loss of the locking possibility and presumably a dis > carding of that panel. The panels are fabricated according to one method in rigid moulds or jigs, where surface material and locks are firmly held in their positions before the interior of the panels are filled by foam by the injection of chemicals. According to a second method, the panels are fabricated in a continuous process where all parts are fed through a double band press at the foaming process. In a third process each panel is glued together of metal and foam sheets. A correct fastening or enclosure by foam of parts as for instance locks, is a trubblesome and costly operation, in particular in continuous fabri¬ cation. Instead of directly fastening parts by sur¬ rounding them by foam, these can afterwards be moun¬ ted in the finished panel. A cavity is machined in the cell plastic core, the part is placed in the cavity and is foamed or glued in place. The shape and construction of the locking halves varies, but the main principal for fastening in the foam is rigid load taking lateral flanges. When mounting panels it is connected with great diffi¬ culties to change the position of faulty lock halves or to mount additional locks. A further possible fastening would of course be to use expanding bolts of known type, but these will, to start with, not give a very good grip and secondly the expansion might easily deform the panels. The object of the invention is to achieve a fastening method and fastening means allowing rigid and sturdy fastening in cell plastic as well as other porous materials, coping with great loads in any di¬ rection, without causing any expansion. It is also the object of the invention to pro¬ vide a method and means for a rigid fastening of locks in panels. The above objects are achieved by a fastening means with two parts, of which the first part is pro¬ vided with a guide that on mounting forces the second part to follow a guide path that at least partly is curved. Possible external forces exerted on the first part are conveyed to the second part, which due to its curved • shape will be very stiff. As a result the second part can be iftade as a very thin blade, which in turn means that it can be very easil bent when pushed along the curved guiding path cutting its own way into the ma¬ terial and secondly that a minimum of termal bridging will result. The invention makes it possible to introduce the fastening forces at any prefered depth in the ma- terial and furthermore a good grip can be achieved without any expanding forces at all. Further advantages of the invention and details will be apparent from the following description and in the drawings shown embodiments of the invention, the examples in no way limiting the scope of the inven¬ tion. In the drawings Fig 1 shows a fastening means seen from above, Fig 2 the fastening means of Fig 1 in perspective and Fig 3 a panel lock using a faste¬ ning means in accordance with the invention. As can be seen from Fig 1 and 2 this fastening means includes a first part 1 in the shape of a plate provided with a slot 2 with a curved inner part.This plate 1 is, at the appropriate place, pushed into a prefabricated slot or opening or cuts its own way through the cellplastic. Thereafter a locking strip 3 of thin sheet material is pushed into the slot 2 cutting a conform path through the cell plastic until the strip reaches the end of the slot. In this position the plate is locked in all directions. By varying the dimensions of the plate 1 and the strip 3, the length of the slot as well as its shape the fastening means can be dimensioned for different objects and the ac¬ tual grip in the cell plastic can be at appropriate distance from the edge or surface of the material. The load is fastened to the plate. In Fig 2 the fas¬ tening means of Fig 1 is shown in perspective with an inserted metal strip 3. When the strip 3 is pushed into the slot it cuts its way through the cell plastic and with its curved inner end the metal strip 3 grips firmly into the cell plastic securing the plate 1 in the cell plastic. Due to the curvature the inner part of the strip will be very stiff and unyielding resul- ' ting in a very firm grip in the cell plastic. Normally the foam materials or cell plastic will exert suffi- cient friction on the strip 3 to retain this in its griping position. Auxiliary locking means may, however, be provided locking the strip in its inserted posi¬ tion. In Fig 3 14 designates a lock-half of known type for panels. These locks consist essentially of a hook in one half of the lock and a pin in the other half of the lock, the hook engaging the pin by a ro¬ tary motion given to the hook via a key inserted through a small hole 15 in the panel. The parts of the lock 14 not being part of the invention are not shown or described. The integral lock 14 and the plate 11 are inte¬ grated in one unit, consisting of two halves of pressed metal sheets. The plate 11 together with the lock 14 have been inserted into a machined cavity and slot in the polyurethane foam core of a panel, of which only a part has been shown. For clarity some of this part has been broken away to show the details of the fastening means. The foam core of the panel is designated by reference numeral 16 and the core is enclosed by two metal sheets 17, one on each side and each provided with an angled edge gripping over the edge of the foam core, which is recessed to give a groove for a corresponding protrusion on an adjacent panel when mounted so that a well protected guiding joint is established. If the plate 11 is sufficiently thin, it is only necessary to provide a cavity for the lock 14 whereas the plate 11 can itself cut its way through the porous polyurethane foam 16. When the lock 14 and plate 11 have been inserted to the intended depth, which essentianlly leaves the outer edge of lock 14 and plate 11 flush with the surface of the foam material. Two metal strips 13 are pushed into slots 12 in the plate 11 * These slots first extend along a straight line, right angled relative the front edge of plate and lock and then,when having passed the lock 14, the slot continues in an inwards turned half-circle. The metal strips 13 cut their way into the foam when inserted into the slot and consequently cut an indentical path in the foam, giving the final position shown in the drawing. When inserted the fric¬ tion between metal the strip and the foam will keep the metal strip in its inserted position and as is apparent from the Fig the strip gives the plate 11 a very good grip in the foam material 16. Due to the curvature of the strip this will become very stiff in its inner end, resulting in a very unyielding grip in a direction trying to pull ut the plate 11 in the same direction as it was inserted. In the inner end the strips 13 are provided with lugs 19 of which only one is shown. These lug ' s are arranged on each side of the plate 11 so as to centralize the inner end of the strip. This is not an absolutely necessary feature of the invention, but it prevents the strip from slid- ing out of grip with the slot when it is pushed into slot and material. Of course further guiding lugs 19 can be provided in the strip b>ut this is not necessary since the tool pressing the strips 13 into slot and foam material can take care of the guiding in the outer end. In this shown embodiment the arrangement of the slots 12 and this the metal strips 13 is symme¬ trical but of course also nonsymmetrical embodiments are possible and it is also possible to allow the different strips to have different radius for the slots at the inner end and they may also be situated at different depths from the front of the lock 14. The friction between the metal blade or strip 13 is quite sufficient to secure that the blade, when once inserted, remains in position. If it .should be discovered that the locks in a panel must have their positions altered, e. g. be¬ cause the panels are placed on ah uneven support, this can easily be done by gripping the external end of the strips 13 with a pair of pliers and pulling them out. Lock and plate 11 are thereafter possible to withdraw, a new cavity for the lock 14 can be made and lock and strips 13 can once again be inserted in their new place. It should again be pointed ut that the inven¬ tion is not limited to the above described examples and in particular it should be pointed but that even though only metal strips curving in one direction have been shown, it is of course also possible to allow the metal strip to curve first in ; one and then in another direction, still resulting in a. very stiff shape. Furthermore the fastening- means of the inven¬ tion may be symmetric or not. In fact a fastening means can be provided with metal strips which extend into different depths into the foam. Furthermore since, as is the case with panels, the most important is that forces can be taken up in the direction of the insertion of the plate the fastening means of the invention can be so made that the length of the metal strip only corre¬ sponds to the length of the curved section and that special tools are extended into the foam material or the guiding slot pushing the metal strip to its working position or the metal strip may in its rear end be narrower. Furthermore the invention is not limi¬ ted to the particular use of metal even though this is most convenient. As has been described above the use of curved slot sections or perhaps one should say guide sections (since the guide not necessarily have to be in the shape of a slot), enables the use of a very tha blade or strip due to the rigidity of curved surfaces . If essentially str.aigth guide sections is to be used, one must (in order to compensate, for the loss of rigi¬ dity) make the corresponding strips or blades thicker or in other ways provided with a greater stiffness. In order to allow such a blade to follow for instance an angled part the blade or strip can be provided with transversal cuts. The strips or blades are preferably flexible but may of course be deformable instead. Within the scope of the invention further deve¬ lopments and appliances are of course possible for the skilled artisan.

Claims: CLAIMS 1. Fastening method for use with porous, granu- lous or other easily penetratable materials charac- terized by that initiallya; first element is inserted into the material, whereafter a second element along a guide in the first element is brought to carry out a curved movement causing the second element to be¬ come curved or angled relative the direction along which the first element was inserted into the material. 2. Method according to claim 1, characterized in that the second element is inserted together with the first element, and brought to carry but the curved movement and become curved after the first element has reached its intended final position. 3. Method according to claim 1, characterized in that the second element is introduced into the material first when the first element has reached its final position. 4. Fastening means for carrying out the method according to any of the claims 1-3 for fastening in a porous, granulous or else easily penetratable ma¬ terial, characterized in that it includes a first element, intended to be inserted into the material and provided with a guide path for a second element, the guide path being curved so that the second ele¬ ment on its insertion into the material and along the guide path carries but a curved movement that at least to some extent angle way from the direction of insertion for the first element so that a curved or angled shape is finally obtained .for the second ele¬ ment. 5. Fastening means according to claim 4, charac¬ terized in that the first element consists of a plate in which is arranged a curved slot for the second element, that is constituted by a bendable strip of metal or the like. 6. Fastening means according to claim 5, charac¬ terized in that the second element is provided with guiding means to secure the symmetrical positioning of the strip relative the plate. 7. Fastening means according to any of the claims 4-6, characterized in that the second element is retained in its place in slot and material by fric- tion only. 8. Fastening means according to any of the previous claims, characterized in that the two ele¬ ments are provided with members for snapping into each other to lock the final curved position. 9. Fastening means according to any of the claims 5-8, characterized in that the length of the strip of metal or the like corresponds to the length of the slot. 10. Fastening means according to any of the claims 6-7, characterized in that it includes several second elements movable along corresponding guides to grip into the material. 11. Fastening means according to any of the claims 4-10, characterized in that the guide, and thus the second element, on insertion over the length where the greatest force is expected is curved. 12. Fastening means according to claim 11, characterized in that the curved part of a guide essen¬ tially is symmetrical relative a line paralell to that of the expected force direction to give a balan¬ ced grip laterally. 13. Fastening means according to claim 11, characterized in that the curvature of the guide and thus the second element is ondulated in order to se- cure a stiff shape for the second element and thus a .sturdy grip in the material

Inventors: MARESCH HEINRICH, MARESCH, HEINRICH
Applicants: MARESCH HEINRICH, MARESCH, HEINRICH
Application year: 1985
Main classification: F16B1
IPC codes: E04B1, F16B1, F16B4, F25D23