# US 5,347,810 A · Damped heat shield > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,347,810 A - Document ID: US5347810A - Status: Granted - Kind: A - Application number: 08/102,158 - Filed: 1993-08-04 - Granted: 1994-09-20 - Earliest claimed: 1992-05-14 - Assignees: Soundwich, Inc. - Inventors: Dan T. Moore, III - Web page: https://patentgrep.com/patent/US5347810A ## CPC - F01N 13/102: {having thermal insulation} - F01N 2260/20: for heat or sound protection, e.g. using a shield or specially shaped outer surface of exhaust device - F01N: GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES (arrangements in connection with gas exhaust of propulsion units in vehicles B60K13/00; combustion-air intake silencers specially adapted for, or arranged on, internal-combustion engines F02M35/00; protecting against, or damping, noise in general G10K11/16) ## Abstract A damped heat shield for a vehicle exhaust manifold includes inner and outer thin steel layers. An intermediate aluminum layer is located between the two steel layers. A high temperature corrosion-resistant coating is applied to the exterior surfaces and the edges of the shield. Such coating along the edges prevents the entry of corrosion producing substances into the interior of the shield. The outer steel layer has a thickness greater than the inner steel layer, so that the two layers do not resonate at the same frequency, and therefore, tend to damp vibrational energy more efficiently and reduce radiated sound energy and noise. ## Claims ### Claim 1 A high temperature damped heat shield for an exhaust system of an internal combination engine, comprising two layers of sheet steel shaped to conform generally to the shape of a high temperature portion of said exhaust system while being spaced therefrom by an air gap, said layers having substantially the same shape and extending in face-to-face adjacency, one of said layers having a first predetermined thickness and having a first resonant frequency, the other of said layers having a second predetermined thickness substantially different from said first predetermined thickness and having a second resonant frequency substantially different from said first resonant frequency causing said shield to damp vibrational energy, and corrosion-resistance means protecting the exterior surfaces of said shield from corrosion at the temperatures encountered thereby. ### Claim 2 (depends on 1) A shield according to claim 1, wherein said corrosion-resistance means is provided by a high temperature paint-like corrosion-resistant coating applied to the exterior surfaces of said shield, said coating also providing a seal between adjacent edges of said layers to resist the entry of corrosion promoting substances to the zone between said layers. ### Claim 3 (depends on 1) A shield according to claim 1, wherein said shield is positioned adjacent to the exhaust manifold of an internal combustion engine in a vehicle. ### Claim 4 (depends on 1) A shield according to claim 1, wherein one of said layers has a thickness of about 0.008 inches and the other of said layers has a thickness of about 0.006 inches. ### Claim 5 (depends on 1) A shield according to claim 1, wherein said high temperature portion of said exhaust system reaches temperatures in excess of 1200.degree. F., and said corrosion-resistance means is a paint-like high temperature resistance coating capable of withstanding temperatures in excess of 1000.degree. F. ### Claim 6 (depends on 2) A shield according to claim 2, the interior surfaces of said two layers of sheet steel being substantially free of paint-like corrosion-resistant coating and being substantially free for movement relative to each other to damp vibration. ### Claim 7 (depends on 1) A shield according to claim 1, wherein said first predetermined thickness is at least about one and one-third times said second predetermined thickness. ### Claim 8 (depends on 1) A shield according to claim 1, wherein the thinner of said two layers of sheet steel is adapted to be adjacent to said high temperature portion of said exhaust system. ### Claim 9 (depends on 1) A shield according to claim 1, wherein a non-ferrous metallic third layer is positioned between said two layers of sheet steel. ### Claim 10 (depends on 9) A shield according to claim 9, wherein said third layer is aluminum foil having a thickness substantially less than the thickness of either of said two layers of sheet steel. ### Claim 11 (depends on 9) A shield according to claim 9, wherein said third layer is aluminum having a thickness of about one-sixth times the thickness of the thinner of the two layers of sheet steel. ### Claim 12 (depends on 10) A shield according to claim 10, wherein said third layer is about 0.001 inches thick. ### Claim 13 (depends on 1) A shield according to claim 1, wherein hems are provided along at least some edges of said shield to maintain said layers nested together. ### Claim 14 (depends on 12) A shield according to claim 12, wherein one of said two layers of sheet steel has a thickness of about 0.008 inches and the other of said two layers of sheet steel has a thickness of about 0.006 inches. ### Claim 15 (depends on 14) A shield according to claim 14, wherein said high temperature portion of said exhaust system reaches temperatures in excess of 1200.degree. F., and said corrosion-resistance means is a paint-like high temperature resistant coating capable of withstanding temperatures in excess of 1000.degree. F. ### Claim 16 (depends on 3) A shield according to claim 3, wherein said vehicle is a passenger vehicle.