Patent ID: 7297897

Claim:
A process for cutting lines of weakness into an automotive trim piece covering an airbag installation, said airbag installation including an airbag adapted to be inflated and deployed upon detection of a collision, said lines of weakness enabling formation of an airbag deployment door opening therein by pressure developed by deployment of said airbag, said trim piece having at least one layer, comprising: partially cutting into a surface of the trim piece by directing a cutting beam from a cutting beam source onto to said surface and moving said trim piece relative to said source of said cutting beam in a predetermined weakening pattern; monitoring the depth of cutting produced by said cutting beam by sensor beams produced from a first sensor and a second outer sensor respectively located on opposite sides of said trim piece and directed towards the trim piece location being cut by said cutting beam, said first sensor located on the same side of said trim piece as said cutting beam source; said monitoring of the depth of cutting produced by said cutting beam including analyzing said first sensor beam and a return beam reflected from said surface after impingement by said first sensor beam by a conoscopic holography process; combining said first sensor sensing beam with said cutting beam so that combined respective segments are collinear with each other when impinging said trim piece surface so as to be continuously directed at the same points along said weakening pattern; controlling the extent of material removed by said cutting beam at each point along said predetermined weakening pattern by controlling said cutting in correspondence with feedback signals generated by said first and second sensors during said cutting; and, moving said trim piece relative to said cutting beam to partially cut said trim piece along said predetermined scoring pattern.