Nut connection.

The invention concerns a nut connection, consisting of a screw with external thread and a mother with corresponding internal thread and a bearing surface, those, screw onable onto the screw, with screwed on mother on an appropriate, at least approximated even attack surface aufliegt.

When screwing a mother onto a screw with high pre-loading against an attack surface the upward gradient first, the bearing surface of neighbouring turn is lengthened and in smaller mass the following threads by the spring rating. With the mother against it within the range of the bearing surface by the spring rating a shortening is caused. Both together results in an upward gradient change, which entail a increased power transmission in the first threads, and thus an uneven power transmission over the length of thread of the Mutter.

From the DE 2,603,996 it is already well-known to avoid the increased power transmission in the first threads and the beginning to cut of the first threads threatening with Uberschreitung of the apparent yielding point of the Materiales by the fact that the thread runout of the mother is expand and outside of the cladding surface of the male thread liegt.

With one by tightening the mother caused deformation cannot thereby the first thread of the mother for the Gegengewindegang of the screw not begin to cut, there he outside from its range liegt.

With more dìeser well-known connection thus no power transmission takes place in the first threads, i.e. that the power transmission to the individual threads differently and unevenly ist.

The invention sits down the task to eliminate the managing stated disadvantages of the state of the art and create a nut connection, with which a gleìchmässige power transmission to all threads ensures with firm tightening of the mother to the Anschlagtläche and an appropriate flexible deformation ist.

According to invention this task is solved by the fact that the bearing surface of the mother exhibits a such weakening that during tightening the mother and the adjustment of the bearing surface of mother and the attack surface a inverting of the mother with an expansion, caused thereby, at least the first thread of the mother auftritt.

By this inverting and expansion or radial deformation of the mother with tightening the Steigungsänderung in the first threads, caused by the spring rating, is caught, so that the power transmission in all threads, i.e. both in the proximity of the bearing surface and at the opposite end at least approximate homogeneously ist.

The invention is described on the basis the enclosed figures. Show:

Fig. 1 a mother in the not screwed on condition in the axial section, Fig. 2 a nut connection with attractive mother, and Fig. 3 the first threads in larger Detail.

In Fig. 1 mother 1 explained on average along the axle A exhibits a conventional internal thread 2. At least one side of the mother 1 a bearing surface 3 is intended, intended those for the attack against an appropriate Gegenfläche connected with a screw ist.

This bearing surface 3 is easily hollow trained, for example through with a small angle A hollow tricks of the bearing surface or by another suitable Bearbeitung.

The opposite surface 4 of the mother can be flat implemented in conventional way, or with advantage with a weakening of same kind to likewise be provided, as the edition side 3, so that the mother from both sides with the same advantages usable ist.

Fig. a nut connection shows 2, with which a mother 1 is screwed onto a screw 5. With the screw 5 positively an attack surface 6 is connected, which planned at a part of 7 connected with the screw its kann.

The mother 1 is screwed with their bearing surface 3 with a certain intended attraction strength up to the attack surface 6 onto the screw 5. Due to the screw forces expenditure-practiced with tightening the mother at the first thread is inverted and extended by a small amount D radially. The mother 1 at its bearing surface 3 is flexibly so far deformed according to the spring rating that itself the bearing surface 3 of the mother 1 of the attack surface 6 at least approximate anpasst.

From in Fig. 3 last thread of mother 1 and screw, represented in the axial section, is to be recognized that due to the radial expansion D of the mother 1 with a change of the upward gradient s and a certain relative shortening h of the mother opposite the screw 5 within the range of the first thread the flanks of the internal thread of the mother 1 and the external thread of the screw 5 aufeinanderlìegen still. In the case of suitable dimensioning of weakening the bearing surface 3 of the mother thus the deformation can be caught due to the screw forces caused by tightening, whereby the Gewindeflanken of mother 1 and screw 5 rest upon one on the other over the entire length of thread and at least approximate with the same Kraft are stressed. For the reaching of the even power transmission desired in all thread segments the concavity 3 is trained concerning angles A and profile accordingly. Usually an angle of less than 1° is sufficient with a kegelstumpfförmigen, for more kugelschalenoder paraboloidförmigen form Rotationsachse.<br appropriate around one the axle A/> for the usual attraction forces for the mother 3 CH 684,707 A5 by this training is pressed at the same time with tightening the mother 1 the last thread radially at the Sohraubenbolzen, whereby security is increased against an unwanted loosening of the nut connection.