Lisi Aerospace

Nicolas Guerin

Anthony Berton

Sebastien Langlais

Sébastien Langlais

It has become apparent that the dimensions of inbuilt-collar driving means of the same nominal size may vary according to the method of manufacture. The dimensions of the collar must therefore be adapted to suit the mode of manufacture, at the expense of its strength or mass. Moreover, the transmissible torque for tightening and loosening operations varies according to a useful wrenching height. In order to have a useful height identical to the height of the shank (), the idea underlying the invention involves pushing the frustoconical collar () of a driving means () in towards its center along the extension of the sides of the shank. The inbuilt-collar driving means proposed by the invention is suited to all modes of manufacture, and can be manufactured without adversely affecting the dimensions of the driving means or its installation.

Polygonal driving means with inbuilt collar

It has become apparent that the dimensions of inbuilt-collar driving means of the same nominal size may vary according to the method of manufacture. The dimensions of the collar must therefore be adapted to suit the mode of manufacture, at the expense of its strength or mass. Moreover, the transmissible torque for tightening and loosening operations varies according to a useful wrenching height. In order to have a useful height identical to the height of the shank, the idea underlying the invention involves pushing the frustoconical collar of a driving means in towards its center along the extension of the sides of the shank. The inbuilt-collar driving means of the invention is suited to all modes of manufacture, and can be manufactured without adversely affecting the dimensions of the driving means or its installation.

A family of devices attach elements previously bored in a cylindrical manner, wherein each device has a in extending along an axis and a tapered shaft and a head, and a bushing intended for accommodating the shaft of the pin, the bushing extending along the same axis having an outer cylindrical surface and an inner tapered surface. The family has at least two devices with bushings presenting, before installation by interference, an identical outer diameter and a different rate of taper of the inner surface.

Family of fixation devices with variable taper

The invention refers to a family of fastening devices including at least two fastening elements (), each one of said elements including a shaped end portion (), a frontal face () of the shaped end portion () having a cavity () extending as far as a bottom (), the fastening elements having different maximum grips (Gmax), the family being configured so that the distance () between the bottom () of the cavity () and the limit () between the body and the shaped end portion is identical for all the fastening elements (). The invention refers moreover to a unit () including such a family of fastening devices and a check gauge (), as well as a method for checking of the choice of the length of a fastening element (), by means of the check gauge ().

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Mery sur Oise, France

Nicolas Guerin