Mufflers for use with engine retarders; and methods
First Claim
1. A method for muffling noise from a system including a truck during operation of a compression-type engine retarder using no more than one muffler;
- the truck having an engine rated for operation at a rated rpm at a selected rpm value of 1800 or above, for a power of at least 500 hp;
the muffler having an outer shell with an outside dimension of no greater than 11 inches and an overall length of no greater than 60 inches;
the method comprising a step of;
(a) muffling engine noise, during operation of the compression-type engine retarder, at an octave band of 1,000 Hz, to no greater than 68 dBA.
1 Assignment
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Accused Products
Abstract
A muffler is described for muffling both positive power and compression brake type engine retarders. The muffler includes an outer shell defining an internal volume. A first, inner, perforated wall is spaced from the outer shell and defines a first, annular, volume therebetween. A first volume of packing material is positioned within the annular volume. An inlet tube is oriented within the internal volume. In certain embodiments, the inner perforated wall circumscribes at least a portion of the inlet tube, and extends a distance of at least 25% of the axial length of the outer wall. Both single and dual muffler systems are described. Methods of use and operation are also provided.
92 Citations
10 Claims
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1. A method for muffling noise from a system including a truck during operation of a compression-type engine retarder using no more than one muffler;
- the truck having an engine rated for operation at a rated rpm at a selected rpm value of 1800 or above, for a power of at least 500 hp;
the muffler having an outer shell with an outside dimension of no greater than 11 inches and an overall length of no greater than 60 inches;
the method comprising a step of;(a) muffling engine noise, during operation of the compression-type engine retarder, at an octave band of 1,000 Hz, to no greater than 68 dBA. - View Dependent Claims (2, 3, 4, 5)
(a) said step of muffling noises during operation of the compression-type engine retarder, is conducted such that the noise is muffled to less than 72.5 dBA at an octave band of 500 Hz.
- the truck having an engine rated for operation at a rated rpm at a selected rpm value of 1800 or above, for a power of at least 500 hp;
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3. A method according to claim 1 wherein:
(a) said step of muffling engine noise includes muffling engine noise in a vertical muffler system using a muffler having a cylindrical outer shell.
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4. A method according to claim 1 further including:
(a) muffling engine noise, during positive power operation of the engine, at an octave band of 500 Hz, to less than 61.5 dBA.
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5. A method according to claim 1 wherein:
(a) said step of muffling engine noise during operation of the engine compression brake includes muffling engine noise, at an octave band of 2,000 Hz, to no greater than 65.5 dBA.
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6. In a muffler arrangement comprising an outer wall defining an internal volume and having first and second, opposite ends;
- the second end being in-line relative to the first end;
an inlet tube oriented partially within said internal volume and adjacent to said first end;
an outlet tube oriented partially within said internal volume and adjacent to said second end;
a first, inner, perforated wall spaced from said outer wall and defining a first, annular, volume therebetween;
the muffler arrangement comprising;(a) a first region of packing material positioned within said annular volume; and
(b) a second region of packing material positioned against, and around a section of, said outlet tube;
said second region of packing material being positioned spaced from said outer wall.- View Dependent Claims (7, 8)
(a) said first inner perforated wall circumscribes at least a portion of said inlet tube.
- the second end being in-line relative to the first end;
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8. A muffler arrangement according to claim 6 wherein:
(a) said first inner perforated wall extends a distance of at least 25% of the axial length of the outer wall.
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9. In a system comprising an engine rated for operation, at a rated rpm value of 1800 or above, for a power of at least 500 hp;
- an exhaust muffler system including no more than one muffler;
each muffler of said muffler system having an outer shell with an outside dimension of no greater than 11 inches;
each muffler outer shell having an overall length of no greater than 60 inches;
the system including;(a) said exhaust muffler system being constructed and arranged to muffle exhaust noise, during positive power operation of said engine to the following;
(i) at an octave band of 250 Hz, less than 58.5 dBA;
(ii) at an octave band of 500 Hz, less than 61.5 dBA; and
(iii) at an octave band of 1000 Hz, less than 63.0 dBA. - View Dependent Claims (10)
(a) said system comprises a truck including a compression brake-type retarder; and
(b) said exhaust muffler system is constructed and arranged to muffle exhaust noise, during operation of said compression brake-type retarder, to the following;
(i) at an octave band of 1,000 Hz, no greater than 68 dBA.
- an exhaust muffler system including no more than one muffler;
Specification