MUFFLER WITH EXTERNAL TUNING TUBE CONNECTING INTERNAL CHAMBER TO EXHAUST CONDUIT

• US 3,583,524 A
• Filed: 09/26/1967
• Issued: 06/08/1971
• Est. Priority Date: 09/26/1967
• Status: Expired due to Term

• Current Assignee: Bert Dubois
• Original Assignee: Bert Dubois
• Inventors: Dubois, Bert
• Application Number:
  US04/670,576
• Time in Patent Office: 1,351 Days
• US Class Current: 181/266
• CPC Class Codes: F01N 1/02 by using resonance
• CPC Class Codes: F01N 13/04 having two or more silencers in parallel, e.g. having interconnections for multi-cylinder engines
• CPC Class Codes: F01N 2490/155 being disposed one after the other in flow direction

Abstract

There is an external tube which connects the exhaust pipe to a chamber of the muffler to provide a means for introducing a long tuning neck into the silencing structure thereby making it possible to attenuate low frequency notes with a minimum size muffler structure.

Claims

1. In an exhaust gas system for an internal combustion engine including a pipe for conveying gas to or from the muffler, a muffler for silencing exhaust gases and including an outer shell and internal silencing and gas flow structure, said muffler having an inlet member and an outlet member one of which is connected to said pipe, said muffler including a closed chamber in said shell, and an external imperforate fully open tuning tube opening freely at one end into the said closed chamber and freely at the other end into said pipe at a point remote from said muffler and located outside of said shell, said tube being longer than said chamber and located alongside and outside of said pipe, the length and size of said external tuning tube and the volume of said closed chamber being interrelated in accordance with the Helmholtz formula and tuned to attenuate a desired frequency of sound.

2. An exhaust system for automotive vehicles, comprising an exhaust pipe, a tailpipe, and a muffler having an inlet connected to said exhaust pipe and an outlet connected to said tailpipe, said muffler having a plurality of sound attenuating chambers acoustically coupled to said inlet and outlet, at least one chamber in said muffler having an elongated throat connected directly to at least one of said exhaust and tailpipes, said throat and chamber being tuned to attenuate a desired frequency.

3. A muffler, comprising an outer shell, a pair of end caps mounted on said shell closing the ends thereof, inlet and outlet nipples, a pair of gas-carrying pipes connected to said nipples, means in said shell forming at least one sound attenuating chamber therein acoustically coupled to said inlet and outlet nipples, and a conduit mounted in one of said end caps and acoustically coupled to at least one chamber in said muffler, said conduit extending outwardly from said muffler for connection to one of said gas-carrying pipes, said conduit and the chamber to which it is coupled being tuned to attenuate a desired frequency.

4. In an exhaust gas system for an internal combustion engine including a pipe for conveying gas to or from the muffler, a muffler for silencing Exhaust gases and including an outer shell and internal silencing and gas flow structure, said muffler having an inlet member and an outlet member one of which is connected to said pipe, said muffler including a closed chamber in said shell, and an external imperforate open tuning tube opening at one end into said closed chamber and at the other end into said pipe at a point remote from said muffler and located outside of said shell, the length and size of said external tuning tube and the volume of said closed chamber being interrelated in accordance with the Helmholtz formula and tuned to attenuate a desired frequency of sound.