Abstract: A passive system for protecting a structure against high temperatures which consists of a thin protective foil of heat-resistant material such as stainless steel fastened to the face of the structure to be protected. When subjected to high heating rates, the local thermal expansion of the foil forms a blister bulging away from the structure to thereby create an air space which thermally insulates the structure.

Abstract: A worn lining indicator for a disc brake friction pad is disclosed which includes a vibrating reed which is adapted to engage the disc brake rotor upon a predetermined amount of lining wear to thereby produce a relatively loud noise to warn the vehicle operator of the worn condition of the friction pad. The reed is carried by a base portion of the warning device which in turn is attached to an unlined portion of the backing plate of the friction pad. The base portion of the warning device includes a pair of projecting detents that are adapted to gauge corresponding intersecting edges of the projecting portion of the backing plate to thereby orient the reed so that, upon engagement of the latter with the rotor, the reed will be aligned along a radius of the rotor.