초록 ▼

An insulated exhaust pipe comprising inner and outer spaced corrugated metallic tubes separated by refractory fiber isulation. Strips of higher density refractory fiber insulation hold the low density insulation in place during operation and prevent degradation of the fiber by vibration. The pipe is

An insulated exhaust pipe comprising inner and outer spaced corrugated metallic tubes separated by refractory fiber isulation. Strips of higher density refractory fiber insulation hold the low density insulation in place during operation and prevent degradation of the fiber by vibration. The pipe is made by rolling the inner tube over a layer of insulation, including strips, to which adhesive has been applied. The insulated tube is then inserted into the outer tube, rotating the insulated tube so that the corrugations of the outer tube do not damage the insulation. Specific structure for carrying out these method steps is disclosed.

대표청구항 ▼

An insulated pipe for use in the exhaust system of a vehicle powered by an internal combustion engine, comprising: an inner metallic tube; an outer metallic tube spaced from and concentrically arranged with respect to the inner metallic tube; and refractory fiber insulation filling the space between

An insulated pipe for use in the exhaust system of a vehicle powered by an internal combustion engine, comprising: an inner metallic tube; an outer metallic tube spaced from and concentrically arranged with respect to the inner metallic tube; and refractory fiber insulation filling the space between the inner and outer tubes; a major portion of the insulation comprising relatively low density refractory fiber insulation which is subject to degradation from vibration; a minor portion of the insulation comprising a plurality of relatively high density refractory fiber insulation strips extending substantially continuously along the length of the inner tube; the high density strips being circumferentially spaced from each other and having a radial thickness to provide a means to inhibit movement of the low density fiber during operation of the vehicle to thereby prevent degradation thereof.