Temperature sensitive device for causing abnormal muffler operation

• US 4,079,808 A
• Filed: 10/23/1975
• Issued: 03/21/1978
• Est. Priority Date: 11/12/1974
• Status: Expired due to Term

• Current Assignee: Iwao Nakamura, Kazutoshi Mizuno
• Original Assignee: Iwao Nakamura, Kazutoshi Mizuno
• Inventors: Nakamura, Iwao, Mizuno, Kazutoshi
• Primary Examiner(s): Franklin, Lawrence R.
• Application Number:
  US05/625,100
• Time in Patent Office: 880 Days
• Field of Search: 23/288 FA, 165/40, 181/37, 181/38, 181/45, 236/48 R, 236/93 R, 236/101 R, 236/101 E
• US Class Current: 181/237
• CPC Class Codes: F01N 1/166 for changing gas flow path through the silencer or for adjusting the dimensions of a chamber or a pipe F01N1/165 takes precedence
• CPC Class Codes: F01N 13/00 Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
• CPC Class Codes: F02B 77/08 Safety, indicating, or supervising devices thermal insulation F02B77/11; monitoring or diagnostic devices for exhaust-gas treatment apparatus F01N11/00

Abstract

When exhaust gases reach an abnormally high temperature, a bimetal valve opens and the muffler operates abnormally to produce a loud noise.

Claims

1. A muffler, for a combustion engine, comprising:

a casing having therein first, second and third chambers which are respectively defined by first and second partition walls within said casing, said first partition wall having an opening for permitting flow of exhaust gases from said second to said first chamber, and said second partition wall having an opening for permitting flow of exhaust gases from said second chamber to said third chamber;

an inlet tube having one end opening into said second chamber for admitting exhaust gases, from a combustion engine, into said second chamber;

an elongated tube having opposite ends respectively opening into said first and third chambers for flowing exhaust gases therebetween;

an outlet tube having one end opening into said third chamber and the other end opening into an atmosphere externally of said casing for flowing exhaust gases out of said third chamber;

an invertible convex bimetallic valve member positioned to cover the opening through said second partition wall for normally closing the opening to prevent flow of exhaust gases through the opening and for inverting when sufficiently heated to open the opening and permit exhaust gases to flow from said second chamber into said third chamber through said opening;

a cylindrical casing having a bottom portion with an opening, said cylindrical casing being positioned within said third chamber and mounted on said second partition wall opposite the opening through said second partition wall to hold therein said invertible convex bimetallic valve member;

a plurality of fulcrums provided on said second partition wall surrounding the opening through said second partition wall and protruding toward said third chamber for supporting a peripheral portion of said convex bimetallic valve member; and

a helical spring disposed between the inner surface of the convex bimetallic valve member and the inner surface of the bottom portion of said cylindrical casing for biasing said convex bimetallic valve member in a direction to sit on said plurality of fulcrums and close the opening of said second partition wall.