Radiation-proof strip for wall and ceiling panel having a groove formed by two bifurcations

Claim 1

A RADIATION-PROOF WALL ELEMENT COMPRISING AN ELONGATED SUBSTANTIALLY FLAT STRIP OF RIGID NONMETALLIC MATERIAL OF UNIFORM WIDTH HAVING AT LEAST ONE LONGITUDINAL EDGE OF REDUCED THICKNESS TO DEFINE A TONGUE AND FORMED AT ITS OPPOSITE EDGE WITH A LONGITUDINAL GROOVE ADAPTED TO RECEIVE THE TONGUE OF AN ADJACENT STRIP, A LAYER OF LEAD SECURED ON ONE FACE OF SAID STRIP COVERING ITS ENTIRE AREA INCLUDING SAID FIRST NAMED TONGUE, AND A RELATIVELY THIN LAYER OF PLASTIC FACING MATERIAL SECURED ON AND COVERING SUBSTANTIALLY THE ENTIRE AREA OF THE OPPOSITE FACE OF SAID STRIP, SAID GROOVE BEING FORMED BY TWO BIFURCATIONS ALONG AN EDGE OF SAID ELEMENT, ONE BIFURCATION INCLUDING THE LAYER OF LEAD, THE OTHER BIFURCATION INCLUDING THE LAYER OF PLASTIC FACING MATERIAL, THE ONE BIFURCATION HAVING A LENGTH SUBSTANTIALLY GREATER THAN SAID OTHER BIFURCATION, SAID TONGUE HAVING A LENGTH EQUAL TO SAID ONE BIFURCATION, THE THICKNESS OF SAID ONE BIFURCATION AND ITS LAYER OF LEAD BEING SUBSTANTIALLY EQUAL TO THE THICKNESS OF SAID OTHER BIFURCATION IN ITS LAYER OF PLASTIC FACING MATERIAL.