Technical Field:

The present invention relates to a fastening means comprising an element so arranged as to extend through a hole in a wall, to which fastening is to be effected, and an organ so arranged as to be capable of being introduced through the hole from an outside surface of the wall to an inside surface of same and of being brought into contact with the wall at that point at the edge of the hole whilst being held at a first end on said element whilst its other end is situated on the outside of the wall where it supports a component arranged for the purpose of sealing the hole and/or securing some object to the wall, whereby the entire means can be assembled from the outside of the wall and can be caused to be secured to the wall by bringing the organ into contact with its inside, so that only the outside of the wall need be accessible-

Description of the Prior Art:

In workshops, for example motor vehicle repair shops, a considerable amount of working time is devoted to the removal and re—fitting of trim components in order to gain access to so—called encrlosed spaces for the purpose of installing items of equipment, for example rear—view mirrors and decorative strips on body panels, and in order to be able to position some form of nut and locking device from the inside.

Similar assembly and sealing problems are encountered with regard to fuel tanks and reservoirs, where in certain cases the additional risk of fire excludes the possibility of performing welding operations and the enclosed space is difficult to reach for inspection and checking. There exists a number of areas, in particular within a number of inspection, repair and maintenance operations, where considerable cost savings can be achieved in the working time required for removal and re—fitting and for the installation of certain spare parts by means of simple external fitting without the need to take special measures inside the enclosed

space in order to arrive at a satisfactory result. The background to the invention is the requirement to rationalize those repair and maintenance operations which today involve considerable working time for the removal and re—fitting of parts in order to gain access to enclosed spaces.

The prior art in this area still involves solutions of the expandable collar, expansion bolt or captive nut with locking device type, or by screwing directly into the material without the use of any internal locking means inside the enclosed space.

Technical Problem:

Those means which are said to represent the prior art are relatively expensive to use, either because they themselves attract a relatively high manufacturing cost because they contain a large number of component parts, or because their installation calls for considerable work, for example a welding operation.

Solution:

In the invention, that organ which is to be situated on the inside of the wall comprises on the one hand a washer made of resilient material consisting of a ring—shaped strip coiled into the form of a spiral, the outer diameter of which is greater than that of the hole in the wall for which it is intended, and having a hole diameter suitable to permit the element to pass through and with a maximum radial width between its outer and inner diameters which is not greater than the diameter of the hole in the wall, so that the washer can be screwed in through the hole in order to be centered on the hole on the inside of the wall, in so doing being brought into contact with the area at its edge, and on the other hand a securing component so arranged as to hold the element securely in contact with the washer, whereby the element is retained by the securing component being provided with support via the washer against the inside of the wall, when the washer is in contact with said inside cf the wall at the edge of the hole.

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Advantages:

When compared with other means and solutions in this area, th present irvenf ^' on is simpler, cheaper, safer and more complete.. fundamental requirement for the screwed fasteners used in sheet metal steel and plastic structures or similar is a locking means enablin the interacting screw to be held in a tightened position, so that i will not work loose under the effect of vibrations. The presen invention fulfils three functions, these being the possibility o entirely external assembly, the absence of a requirement for special means or tools inside the enclosed space apart from the fastenin organ itself, and finally the locking function.

The object of the present invention is thus to provide a improved means for effecting the external assembly of items o equipment and/or sealing in structures having enclosed spaces.

Description of the Drawings:

The invention is described below in relation to two embodiments, of which the first has two variants, with reference to the accompanying drawings in which Figs. 1, 3 and 4 show a design having an enclosed space as a section through a hole in which the fastening means in accordance with the first embodiment of the invention is shown in various satgeε of assembly; Fig. 2 shows a part of the fastening means in the first variant and in perspective view; Fig. 5 shows the same part in the second variant; Fig. 6 shows the second variant in side view; and Fig. 7 shows it in front view.

Description of the Preferred Embodiments:

The fastening means in accordance with the first embodiment of the invention is shown in the drawing to consist of a washer 1 capable of being compressed into a plane form, elastic, and open by means of a slot, said washer in accordance with Fig. 5 being able to exhibit the form of a helical flat spring 12 . Its radial dimension is greater than that of a drilled hole 11 , or any other opening or similar in the aforementioned structure 8 having an enclosed space 10 , in which hole the fastening means is to be assembled. The washer 1 exhibits a hole, and its radial width between the edge of that hole

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and the outer diameter of the washer is less than the diameter of said hole 11 in the wall of the structure 8 minus an assembly allowance for a fastening element which will be described below.

Said fastening element, which has the form of a screw 3 , is provided with a groove 4 . The distance between the bottom of the groove and the outer diameter of the screw constitutes said assembly allowance. The groove 4 is situated at one end of the screw, which is referred to as its inner end, whilst the outer end of the screw is provided with a head 13 or similar beneath which a washer 5 is shown to be situated.

To the means there also belongs a nut which runs on the thread of the screw 3 . The outer diameter of the nut 6 is so great that it is able to pass through the hole 11 in the structure, but not through the hole in the washers 1 and 12 .

The washer 1 and its corresponding, screw—shaped washer 12 are provided with Locking points 2 , to which depressions in the nut 6 correspond.

In the second embodiment in accordance with Figs. 6 and 7 the organ is executed in the form of a coherent whole, to which the reference designation 14 is applied in Fig. 6. Here, too, there is a screw—shaped washer 15 and a fastening component in the form of a nut 16 , as well as a supporting washer 17 . These three components are, as has been stated, combined to form the unit 14 , and the Figures show that this can be achieved by means of rivets 18 and 19 .

Fig. 7 shows the helical spring—shaped washer 15 in front view, although the supporting washer 17 has been removed and is indicated only by means of broken lines. The washer 15 thus exhibits a hole 20 and a periphery 21 , which is in the form of a circular arc but does not extend around the entire washer, and is interrupted by an incision which forms a first, small flap 22 at the edge of the hole 20 and a second, similar flap 23 . The flap 22 is connected by means of the rivet 18 to the nut 16 , and the flap 23 is connected by means of the rivet 19 to the supporting washer 17 . The ends of the flaps 22, 23 do not meet each other, since they constitute the extremities of the radial section through the washer, which are necessary in order for it to be given the form of a coil

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spring; see in particular Fig. 6. In order to facilitate the takin hold of the washer as it is screwed into the hole in the wall, th connecting edge extends in an inclined fashion between the flap 2 and the periphery 21 , whilst the corresponding connecting lin for the flap 23 should preferably extend radially in order to leav aε much of the periphery 21 as possible uncut.

When assembling the means in accordance with the embodiment i Figs. 1—5, the washer 5 is placed on the screw 3 followed by th washer 1 (or 12 , if the second embodiment is preferred), and th nut 6 is screwed onto the outer end of the screw 3 .

The nut 6 is then introduced through the hole 11 and th entire means is pushed through to an uncentered position. A check i then made to ensure that the washer 1 (or 12 ) is located in th groove 4 of the screw, whereupon the screw—shaped washer is screwe in through the hole. It will now be in an inclined position, so tha only its radial width between the edge of its hole and its oute diameter need be accommodated in the hole, but not, on the other hand the width across its entire outer diameter..- In addition th aforementioned assembly allowance must be accommodated in the hole this being the distance between the bottom of the groove 4 and th outer diameter of the screw 3 . This initial stage in the screwing—i of the washer is shown in Fig. 3. Once it is complete, the washer wil be situated inside the space 10 within the wall 8 of th structure. This is shown in Fig. 1, where the next stage, involvin the centering of the means so that the screw 3 is located centrall in the hole 11 , is also shown.

By drawing the screw outwards during the centering operation o the hole 11 , the washer 1 will come to rest against the edge o the hole, since the outer diameter of the washer is greater than that of the hole. At the same time the nut 6 will come into contact wit the washer 1 . The locking points prevent the rotation of the nut, permitting the screw 3 to be tightened. If sealing only is required, the means in the finished state will be in the condition illustrated in Fig. 4. In this case the fastening means is used only for the purpose of retaining a sealing organ, which in this case consists of the washer 5 , which may be elastic.

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It is possible, however, for some other element such as the motor car equipment mentioned by way of introduction to be supported beneath the head 13 of the screw. .-

The coil spring—shaped washer 12 is used essentially in the same way as the washer 1 , but must be screwed for a number of turns in order to pass through the hole 11 .

When assembling the means in accordance with the embodiment in Figs. 6 and 7, it is not necessary to introduce any element corresponding to the screw 3 at the same time as the organ is being fastened, said organ being represented in this case by the unit 14 . Instead, the organ 14 is held against the supporting washer 17 , and the nut 16 is introduced via the hole in the wall. The means is then pushed in so that the flap 22 with its inside at the hole 20 will come to rest against the edge of the hole in the wall. It is then possible to screw in the washer 15 by turning the supporting washer 17 « This is conditional upon adequate space being present for the thickness cf the wall between the nut 16 and the broader part of the washer 15 where the periphery 21 begins. The hole in the wall must have a diameter which will accommodate the radial width of the washer between the edge of the hole 20 and the periphery 21 . The permissible thickness of the wall will depend on the degree of outward bending of the flap 22 ; see Fig. 6. Since the flap should not be made too long, and may also not be bent too sharply _/ ^" the embodiment in accordance with Figs. 6 and 7 is most suitable for thin walls such as are encountered in sheet metal structures.

Once the unit 14 has been screwed by about one whole turn, the flap 23 will extend from the supporting washer 17 , which is located on the outside of the wall, to the broader part of the washer 15 between the hole 20 and the periphery 21 at the extremity of the flap 23 , In this case, too, it is necessary for the flap to extend over the thickness of the wall. The unit can now be centered in the hole because in the radial sense this need only accommodate the thin flap 23 . The radial width of the flap must not, therefore, be so great as to prevent it from being accommodated in the hole in the wall once the means has been centered, and the hole in the wall must be dimensioned^ as has already been mentioned, in accordance with the

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radial width of the washer between the hole 20 and th periphery 21 .

Once the unit 14 has adopted this position, it is held securel against the wall with the supporting washer 17 outside and th washer 15 together with the nut 16 inside the wall. By making th 'clamping dimension' inside the supporting washer 17 slightl smaller than the wall thickness, the spring fastening of the unit wil be achieved, thereby making it easier for it to be held in a centere position.

Finally the fastening element is introduced, which, since th fastening component is the nut 16 , consists of a screw. Whe threading the screw into the nut 16 , a check must first be made, o course, to ensure that any component parts which are to be fitted b means of the screw have been run up along it. As the screw i tightened, the nut 16 will be drawn inwards towards the inside o the wall whilst the washer 15 is compressed, when the washer 1 will provide additional support. Finally, the washer 15 will com into contact with the edge of the hole in the wall over most of it periphery, and thus with the section 21 of the periphery. The nu 16 for its part will rest against the washer. The nut is prevente from rotating during the tightening operation, as it is attached vi the washer 15 to the supporting washer 17 , which in turn can b held from the outside. During assembly the screw can be removed an the unit 14 will remain in position, so that the screw can b screwed in once more without the need for any other assembl operations.

Industrial applicability:

The invention can be used in practice for a number of different applications relating to the production of new goods, and within th repair and maintenance sectors, above all for sheet metal and steel structures.

The means in accordance with the invention may be modified within the scope of the following Patent Claims. It can thus be suited to different areas of application, to which reference has been made briefly above. The second embodiment in accordance with Figs. 6 and 7,

in particular, can be executed as any one of a number of different designs, with regard both to the production design and to its adaptation to suit the intended application. Thus, the nut may be replaced by some other fastening organ such as a bayonet cap or a snap Lock. The fastening organ can be held securely to the washer in some other way than by the rivets shown here. It is also possible in certain designs to integrate the fastening organ fully with the washer by providing the inner end of the washer with a special form, for example with stamped and folded sheet metal parts. The outer supporting washer, too, can be given other forms and can be secured in a manner other than by the screw—shaped washer. It can, for example, be executed with a gasket for the purpose of sealing holes, but without the use a special sealing washer being necessary. It can also be executed with a tool grip facility, for example so that it can be tightened by mechanical means. The supporting washer can also be integrated with the unit that it is wished to fit using the fastening means. It may, for example, take the form of a hook or a holding means. The fastening element can also be modified. It must naturally possess a form which mat-ches that of the fastening component and must not, therefore, be in the form of a screw if the fastening component has a form other than a nut. Its outer part can be so executed as to form not only a head for use in conjunction with the assembly of the element, but also a holding organ, for example.