Attachment device and method to apply it. BACKGROUND OF THE INVENTION

The present invention seeks to provide a locking and ten- sioning device, where a movable aperture in a plate or yoke is forced from or against two supporting rigid points or a line between theφ. The tensioπing forces on the device acting sub¬ stantially perpendicular to the length direction of the device, which when turned, will change the tension in the plate or yoke in a way similar to the driving in of a wedge.

Well known are bults, rivets and nails. They mainly take up forces in their length direction. The wedge, an other old device, works with forces nearly perpendicular to the direction in which it is forced. As a section of a wedge i similar to the cross section of a cone, a cirkular cone should have essentially the same function as a wedge.

Twq Swedish inventions make use of this similarity, Ref 1. In both a cone with circular cross section is used as a wedge. Instead of forcing the cone through apertures,a helical groove or conical thread in the surface cf the cone engages one or more rims of those apertures, when the cone is tυrnsd. This causes a movement of it along its axis. As the cross section of the cone normally is less than the apertures, in which they operate, a fast working mechanical component is found. However this cone with one or more threads along its surface is very difficult to produce in an industrial way. The present invention has eliminated this disadvantage especially on occations where steel has to be used. In a very simple realization of the invention, it is made possible for everyone to produce a working device containing the function of a wedge and threaded cone but not the disadvantagees of both. OBJECTS OF THE INVENTION

The present inventions seeks to provide the use of a turnable wedge, which is possible to produce in an industrial way. Thus the difficult turning of a conical thread is eliminated. A smooth cone without grooves also eliminates scratching on supporting points or the line between them. This improves the durability of applied finnish or aint.

An other disadvantage of the threaded cone, namely to fall out of apertures when loosend has further been eliminated when the cylinder is conected to the thick end of the cone. Rapid fas¬ tening and losening can thus be performed for eventual adjustments despite the apertures having larger openings than the cross section of the cone or cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

The theory behind the invention is best understood with refe¬ rence made to the accompanying drawings, in which: Fig. ,1. shows a flat we-dge placed in three apertures in thre different plates,

Fig, 2 shows the same arrangement of the three plates as shown in Fig. 1 the wedge-however having been -replaced by a cone.

Fig. 3 shows an arrangement similar to that in Fig. 2, where the support from apertures in ^' two plates has been replaced by a line support along the generatrix of the cone.

Fig. 4 shows schematically different loading graphs in cases where wedges or the invented smooth cone with connected threaded cylinder is used, Fig. 5 shows one example of the invented attachment device, where the cone is divided in two parts with a threaded cylinder in between,

Fig. 6 shows an other design of the invented device, the threaded cylinder now being placed at the thick end of the cone, Figs. 7 - 10 shows example of use of the latter device.

Fig. 11 shows in perspective view the cone with line load along the generatrix of the cone.

Fig. 12 shows a section of the object shown in Fig. 11,

Fig. 13 shows theoretically the same device as in Figs. 11 an 12, the straight generatrix of the cone being mathematically replaced by two points. DISCLOSURE OF INVENTION

The invented teπsioning device and its use is best explained with . reference to the Figs. 1 - 3 and the schematic loading graphs in Fig. 4. In Fig. 1 a flat wedge 1 engages two plates 3 and 4 with pulling forces A and C. Those forces are in equilibrium with the-

can move along the surface of the wedge, as this is not part of the invention. Known means to prevent such a movement can be applied. The wedge in Fig. 1 has a rectangular cross section.

The same function can be achieved with a cone 2 with circula cross section as can be seen in Fig, 2. Those two loading cases are shown as Fig. 4c and Fig..4d. The force B in Fig. 4c can be divided in two parts one of which parallell to the forces A and C and one perpendicular to the latter. If however the angle of the wedge or cone is small one can neglect the component of B perpendicular to the forces A and C and disregard the differenc between the loading cases 4c and 4d. The loading case 4a descibes cleaving with a quoin.

The case in Fig 4b describes a line load as shown in Fig. 3. Here the cone got a line load along a generatrix, the load coming from forces A and C acting on the plate 6. Through a narrow elongated opening 7 in the plate 6 a.plate 5 with an aper¬ ture is inserted. This plate has the same principal function as a yoke both !"..-ving apertures larger than the cross section of the cone 2. If the elongated opening 7 is narrow, the loading case correspond to case 4b. ' A broader opening will give case 4f. The cone 2 in Figs. 2 and 3 can with a hammer easily be forced in the shown apertures, which is a wellknowπ operation. The friction will prevent the cone from popping back if the angle of the cone is small. If the cone has a grove or helical thread along its surface, DE 2757479 shows that design and partly the function of the device, that the present inventor aimed at and wanted to use but could not produce in an industrial and economic way. The threaded cone will engage some or all the apertures in plane 3, 4 and 5 in Fig. 2 or the plate 5 in Fig. 3.

The invented device consists of a smooth cone conected to or interupted by a cylinder, th'άt has been threaded. In Fig. 5 one example of the interupted case is shown. Its use can be seen in Figs. 11 - 13. This device has an upper conical part 8 and a front conical part 10 and in between a cylinder 9. Somewhere on the device arrangements for turning the sπme like vellknown screw driver slots, bolt head or the like is found, preferably at the thick end of the cone 11.

In an other mode of the invented device the threaded cylinder is connected to the thick end of the cone, which* is shown in Figs. - 10.

On designing it has been found very advantageous to let given dimensions and endpositions of the plates 3 - 5 or the plate 6 and the aperture in plate 5 be such , that a slight pressing force at the end of the conical device with threaded cylinder will bring t in a position, where the thread in the cylinder will engage the rim of plate 5. A later turning of the conical device will then bring tension in the said plate. From the draw¬ ings can be seen that in function the conical device and its connected threaded cylinder has a substantially smaller cross section than the openings for passing the respective part of the device. MODES FOR CARRYING OUT THE INVENTION

That the threaded cylinder can be connected to the thick end of the cone is shown perspectάvely in Fig. ό. There is further shown that the plates 3 and 4 can be joined to each other. This is indicated by the dotted connection 12. Known arrangements are available for rigid or articulated connection. Known means to prevent the plane 5 to move along the length of the cone are also available. The function however is such, that a turning of the conical device with connected threaded cylinder will cause a movement substantially in the direction of the device. Hereby the contact point on the cone will be changed on the supporting point ' 3. The cone will -turn around the other supporting point 14 for the cylinder.

If the plate 5 is prevented from moving sideways to or against the plates 3 and 4 or both the contact point 15 between the rim of aperture in plate 5 in the line of the force B is reinforced. On the other hand this will not occure when the movement side σys is free. A section of this arrangement through the centre of the cone and cylinder is shown in Fig 7. Every man skilled in the art understands, that the directions of the forces AS and C can be turned as shown in Fig. 8.

The plate 5 can be made .thick and fill upp the space between the plates 3 and 4. This crrangβment 16 is shown in Fig. 9. A be _¬ velling tapering 17 of the part in contact with the cone has

proven favourable. If all the space between the plates 3 and 4 is filled, movements in the direction of the cone* is prevented.

In Fig όσ is shown an aperture 18 in the plate 3. In many production operations especially in designs like those shown in 5 Fig. 9, one wants to make small changes in tsnsioning force withou the tensioning device falling out. A fast assembling might also be wanted at the same time. The fast assembling is achieved from the large aperture 18. The cone with connected cylinder might then be blocked from falling out, when the supporting rim of 10 the aperture 18 is given substantially the same cross section 19 as the threaded cylinder. This speciality is _, shown as Fig 6b. A groove in the cylinder with a width a little bigger then the thicknes of the plate will give a solid engagement to the thread, which has been very favourable. Even if the plate 3 originally 15 is flat, it will become bent to follow the lead of the thread in the cylinder. The aperture part 19 can be made narrower to fol¬ low half the way around the cylinder in the bottom of the thread groove.

Naturally it is possible to exchange the line load from the 20 part 16 - 17 in Fig. 9 with a plate as shown in Fig. 10. A slot 20 for a screw driver is found at the end of the threaded cy¬ linder. This corresponds to loading case found in Fig 4h. If the cone in Fig. 3 is replaced by the invented cone with thre'aded cylinder in Fig. 5 an arrangement as shown in perspective 25 view in Fig. 11 will be obtained. A section partly through the axis of the" cone is shown in Fig. 12. The nonsectionized part, the end of the device, shows a head of a .bolt 21.

A turning of the cone with threaded cylinder in Figs. 11 and 12 will cause a movement of the plate 5 in the slot 7. If movement 30. is prevented a tension in plate 5- will change. The movement is less than in the case with a cone with a contiπous groove along its surface. ere used. That arrangement .similcr to those decribed in DE 2757479, will give a larger movement or change in tension. The difficulty to manufacture a cone with a groove along its 5 whole surface motivates the more economically invented design with a *mooth cone and a connected threaded cylinder. Schematically this resembles the loading case Fig. 4f.

This loading case has a line load along a generatrix of the interupted cone. If the plate 6 is sufficiently rigid and, strong

the same keyed joint as in Fig. 12 can be obtained by very simple means. The cone and its function can be replaced by two supporting points on the generatrix describing mathematically the cone or interrupted cone as shown in Fig. 13. The upper part of the cone 8 here has been replaced by a thin washer, that is rounded at its outer rim. A pointload against the the plate 6 will be found as 23 on the "cone" with threaded cylinder. The other part of the generatrix of the "cone" is calJed 24, which is the rounded end of the threaded cylinder 9. Point contacts with the plate 6 is obtained when the device is turned, and the plate 5 is moved being in engagement with the cylinder. If the plate can not move tension can be built up in the plate 5.

A cone with threaded cylinder can easily be made of a bolt. On the bolt a washer is fastened with a nut βsainst- the head. The must then be substantially larger, than the nut to prevent contact with the plate 6. An imaginary cone with threaded cylinder has been made. Fig. 13.

In Fig. 6 has been shown, that the cylindrical part can be put at the thick end of the cone. In Fig. 11 the cylinder interupt the conical surface. Everyone skilled in the art understands that the threaded cylinder also can be placed at the smallest part of the cone. In Fig. 11 is shown that the threaded cylinder conti- noυsly becomes a smooth cone. Nothing in function prevents the cylinder being far larger in cross section than the conical part.

With substantially less cross section of the cylinder the advantag is achieved in many practical cases, that the device will not fail out when losened. This advantage will not be found on cones with helical grooves along their surface.

Generally the figures show straight cones with circular cross sections, perpendicular to the axis of the cones. In vibrating assembleys it might hapeπ, that the devices will come loose. In the field of the present invention this can be neutralized by re¬ placing the generatiing circle with a polygone. Favourable for the design in Fig. 13 is then making the outer rim of the washer octogonal

In fig !0 the bottom slot was deliberately made very broad so that resemblance with the loading case 4h should be obtained. If the slot is smaller the point of the cone will rest on the

like in Fig. 4e where the forces A and C have been replaced by a line loσd. This overestimation will cause the cone to turn aroun the support against plate 3 while the plate 5 is further pulled out. It is possible for the skilled man to chose thic nes of the plates 3 and 5 in a way, that wanted balancing of the tensions in those plates is obtained. It is thus also possible to apply tension stepwise in several plates 5 in the Figs. 6 and 11. where the elasticity and tension built up will"guide the order .of ^' function. REFERENCES

1. SE 7614460-9 similar to DE 27 57 479 -

2. SE 7714385-7

BAD ORIGINAL