Method of fixing by welding an interface support on a profile of a vehicle seat slide

A method of fixing, by welding, an interface support on a profile of a vehicle seat slide rail, the method comprising the steps of:

• providing an interface support having at least one wall with an inner face, and providing a slide rail profile having a substantially U-shaped cross-section with a transverse wall interconnecting two side walls, the side walls being substantially parallel to each other and the transverse wall being substantially perpendicular to the side walls, the transverse wall and each side wall having an inner face and an outer face,
• positioning the interface support with the inner face of its at least one wall against the outer face of a wall of the profile,
• creating a welding joint between the wall of the interface support and the wall of the profile by moving a laser beam, emitted from an emitting source, relative to the wall of the profile, while keeping the laser beam in a position such that it passes successively through, and in this order from the emitting source:
• the inner face of the wall of the profile, then the outer face of the wall of the profile, then the inner face of the wall of the interface support, and while the laser beam remains within the wall of the interface support.