MUFFLER FOR INTERNAL COMBUSTION ENGINE

• US 3,672,464 A
• Filed: 09/16/1970
• Issued: 06/27/1972
• Est. Priority Date: 09/16/1970
• Status: Expired due to Term

• Current Assignee: Douglas W. Rowley, John A. Campbell
• Original Assignee: Douglas W. Rowley, John A. Campbell
• Inventors: Rowley, Douglas W., Campbell, John A.
• Primary Examiner(s): Wilkinson, Richard B.
• Assistant Examiner(s): Gonzales, John F.
• Application Number:
  US05/072,678
• Time in Patent Office: 650 Days
• Field of Search: 181/44,47R,48,63,46,57,59,41,49
• US Class Current: 181/253
• CPC Class Codes: F01N 1/003 by using dead chambers communicating with gas flow passages resonance chambers F01N1/02; chambers containing sound-absorbing materials F01N1/24
• CPC Class Codes: F01N 1/06 by using interference effect

Abstract

A muffler for internal combustion engines which employs a converging-diverging nozzle and a length of perforated tubing to effect sound attenuation with minimum back pressure. The perforated tube is axially disposed in a cylindrical casing, projecting forwardly from the muffler outlet and defining alternate flow passages. The nozzle member is disposed in the perforated tube, its mouth positioned at the tube inlet and spaced downstream from the muffler inlet. An imperforate baffle disposed in the annular passage between the perforated tube and cylindrical casing intermediate the ends of the nozzle member lengthens the passage with respect to the alternate, causing the divided gas flows to travel different distances prior to recombination and exhaust.

Claims

1. A muffler comprising:

a housing defining a longitudinal chamber having an inlet and an outlet;

a perforated tube disposed in substantial axial alignment with the chamber inlet, the perforated tube having an inlet end spaced a predetermined distance from the chamber inlet and an outlet end communicating directly with the chamber outlet;

an imperforate nozzle member disposed in the perforated tube, the nozzle member having a mouth generally conforming to and disposed at the inlet end of the tube, and a portion converging to a throat and a portion diverging from the throat to an outlet conforming to the perforate tube; and

an imperforate baffle disposed in the passage between the perforated tube and the housing intermediate the ends of the nozzle member, the baffle constructed and arranged to divert the flow of exhaust gases between the outer surface of the nozzle means and the perforated tube.

2. The muffler as defined by claim 1, wherein the housing, the perforated tube, the nozzle member and the imperforate baffle are circular in shape and concentrically disposed.

3. The muffler as defined by claim 1, wherein the constituent parts of the muffler are constructed and arranged to divide flow through the passage between the perforated tube and the housing and the passage through the nozzle member essentially equally.

4. The muffler as defined by claim 1, and further comprising a second perforated tube having an inlet end and an outlet end, the second perforated tube being of the same size as the first claimed perforated tube and disposed in spaced axial alignment therewith, the inlet end of the second perforated tube communicating directly with the chamber inlet and the outlet end being supported within the housing by an imperforate member.

5. The muffler as defined by claim 1, wherein the divergent portion of the nozzle member tapers more gradually than the converging portion.

6. The muffler as defined by claim 1, wherein the imperforate baffle supports the perforated tube within the housing.