Lisi Aerospace

Benoit Regnard

Martial Broucke

Julien Goyer

Florent Verdier

Dimitri Billaud

Clément Rousseau

A method for the installation of a threaded fastener () in a structure, the threaded fastener comprising a screw () and a nut (), the method comprising the following steps: The process further comprises determining the thickness of the structure to be tightened, and determining the target value of the first parameter in accordance with the thickness of the structure to be tightened and the geometrical characteristics of the fastener ().

Method for the servo-installation of a threaded fastener

This relates to a method for the quality control of a blind fastener installation in a structure comprising a sleeve and a core bolt, with a deformation of a rear side of the structure, a signal being generated during the installation process. The process includes a) identification of two notable points of the signal, chosen among: pulling start point (S); buckling (B) of the sleeve; contact (B, S) of the sleeve or of the core bolt; force setpoint (B) or fracture (S) of a portion of the core bolt; b) estimation of a first parameter as a function of a notable point, characterizing a bulb in contact with the rear side; c) estimation of a second parameter as a function of a notable point, characterizing a tension applied in the core bolt; and d) for each estimated parameter, comparison with a condition that indicates the proper installation of the fastener.

Method for controlling the quality of a blind fastener installation

The invention concerns a metal attachment for providing an electrically conductive surface through the entire thickness of structural elements to be assembled. The attachment thereby comprises a head () and a smooth shank () extending along an axis of revolution, characterized in that the shank comprising at least one conductive portion () and one lubricating portion () disposed along the axis of revolution of the attachment along at least one length of the shank. The attachment according to the invention provides a conductive surface through the entire thickness of the structure in which it is installed. The attachment according to the invention is intended, in particular, for aeronautical applications.

Metal attachment

The present invention pertains to a washer () for a female fastener (A), particularly a nut or collar, said washer comprising an annular base () and a substantially cylindrical skirt () of an outer periphery of the annular base, said annular base comprising a central orifice () coaxial with the axis () of the skirt, characterized in that the annular base is at least partially covered with a layer () of a viscous composition capable of forming a liquid-tight coating through polymerization. When installing a nut having such a washer onto a male fastener such as a pin (), the spreading of the viscous layer makes it possible to fill in the gaps () of the assembly, the polymerization of the composition ensuring its leak-tightness afterwards.

Leak-proof fastening device

The invention relates to a metal fastener that makes it possible to ensure an electrically conductive surface along the entire thickness of structural elements to be assembled. The fastener thereby comprises a head and a smooth shank extending along an axis of revolution, characterized in that the shank comprises at least one conductive portion and one lubricating portion disposed along the axis of revolution of the fastener along at least one length of the shank. The inventive fastener makes it possible to ensure a conductive surface in the entire thickness of the structure in which it is installed. The inventive fastener is particularly intended for aeronautical applications.

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Saint Germain de la Grange, France

Benoit Regnard