An outer hearth pad is provided with a frame for overlying the elevated peripheral edges of an outer hearth. A padding material is secured to the outer surface of the frame by a covering material overlying the padding material, the covering material being secured to the inner surface of the frame. The...http://www.google.es/patents/US4903686?utm_source=gb-gplus-sharePatente US4903686 - Outer hearth pad
