Patent ID: 7311124
Filing Date: 2007-12-25
Classification: B29C,B29K,B29L,B60G,F16F

Abstract:
1. A method of making a spring wire comprising at least one layer (C) of a fiber wound helically on a cylindrical “primary” portion ( 12 ) of diameter equal to D, the tangent to said helix making an angle relative to the axis ( 100 ) of the primary portion ( 12 ) having a value β, said layer (C) also being suitable for being bonded to the primary portion ( 12 ) by a matrix (Rp), the fiber, once wound around the primary portion, presenting a cross-section that is substantially rectangular, of thickness E in the radial direction of the primary portion ( 12 ) and of width E′ in the direction perpendicular to the tangent to the helix, the method consisting in preparing a funnel ( 13 ) of frustoconical shape, said funnel having a small opening ( 14 ) corresponding to the small base of the frustoconical shape, in preparing a supply ( 15 ) to deliver the fiber (Fb 1 ), in connecting one of the ends ( 16 ) of said fiber to the primary portion ( 12 ), and in imparting rotary movement (R) to said supply ( 15 ) at a speed ω about the axis ( 100 ) of said primary portion ( 12 ), said primary portion being moved in translation ( 17 ) at a speed T through the funnel ( 13 ) along its axis going from its large opening ( 24 ) towards its small opening ( 14 ), the method being characterized by the fact that it further consists in causing said fiber (Fb 1 ) to penetrate into the funnel ( 13 ) via its large opening corresponding to the large base of the frustoconical shape before being rolled up around the primary portion so that it comes to lick the frustoconical interior wall of the funnel, the angle at the apex of said funnel ( 13 ) having a value that is substantially equal to 2β, the small base of the frustoconical shape of said funnel having a diameter equal to D+2E, the value ω of the speed in rotation of the supply ( 15 ) expressed in revolutions per second, and the value T of the speed in translation of the primary portion ( 12 ) expressed in meters per second being associated by the following relationship: