US1414979A | 1922-05-02 | |||
GB668859A | 1952-03-26 |
According to the technique that is applied up to today, the screw and the screw nut are traverse perforated and inside of the hole a pin is placed so that turning the screw nut the screw is turned, in order to accomplish the bolting, since is not feasible the bolt of the screw with the rotation of his head. The hole, ; which is made on the screw, has as a result the reduction of his cross-section and his strength. The inside surface of the hole is not able, to be galvanized so the oxidation is more often.
The power, which is transferred from the screw nut to the screw, through the pin, has as a result the breaking of the pin in many cases. For that reason the bolting is not proper since the requested powers are not applied on the screw nut because of the fear of breaking the pin.
Advantages of the suggested method are that the strength of the screw in not reduced, since is not perforated, is being galvanized through all of its surface and finally the bolting is more easier and more secure since we avoid the use of the pin.
Main characteristic of the screw-screw nut pair, according to the present method, is that the body of the screw (3) is not round but it has polygonical form (1).
Respectively the inside hole of the screw nut has the same shape (2). The screw is placed inside of the space-frame's rod (5) as a result; the bolting is not sustainable, with the turning of screw's head (6).
For that reason the placing of the screw nut is necessary (4) in order to surround the body of the screw (3) and of course their polygonical surface (1), (L) to come in touch.
With that way turning the screw nut (4) the screw (3) is turned too and the bolting is succeed.
The number of the angle of the polygonical surface (1), (2) is depend on the screw's size.
In the figure (1) we are able to see the ichnography and profile of the screw (3) and screw nut (4), where we can see the polygonical surface (1), (2). In the figure (2) we can see the placing of the screw (3) and the screw nut (4) on the rod of the space frame (5).