Expansion type silencer

Claim 2

A muffler comprising an elongated housing having an inlet and an outlet, an inlet gas flow tube in said housing connected to said inlet and an outlet gas flow tube in said housing connected to said outlet, at least two transverse partitions in said housing subdividing it into at least three transverse chambers, one of said chambers comprising a first expansion chamber and another of said chambers comprising a second expansion chamber, first means connecting said inlet tube with said first expansion chamber so that gas from the inlet tube flows into the first expansion chamber, second means connecting said outlet tube with said second expansion chamber so that gas in the second expansion chamber flows into the outlet tube, and a substantially imperforate intermediate tube supported by said partitions having a predetermined length and having an inlet end opening into the first expansion chamber and an outlet end opening into the second expansion chamber to provide a path for gas flow from the first to the second expansion chamber, said first means and the inlet end of said intermediate tube forming the only ports for the first expansion chamber and the second means and the outlet end of the intermediate tube forming the only substantial flow ports for the second expansion chamber, the length of said intermediate tube along with the length of the expansion chambers and the ratio of the areas of the chambers and intermediate tube being selected to tune said chambers and tube to attenuate a broad band of sound frequencies having a substantially predetermined cutoff frequency at the low end of the band, said first and second expansion chambers being longitudinally adjacent to each other and said intermediate tube being supported by the partition separating said expansion chambers, the third of said transverse chambers forming a part of one of said means.

Claim 3

A muffler as set forth in claim 1 wherein at least one of said inlet and outlet tubes has a perforated wall to provide means for attenuation of frequencies higher than said broad band.

Claim 4

A muffler as set forth in claim 2 including a third transverse partition acting with said two partitions to subdivide the housing into four transverse chambers, the fourth of said chambers being located between the third chamber and one of the expansion chambers and including gas flow means connecting said one expansion chamber with said third chamber, said gas flow means along with said third chamber forming a part of said one of said first and second means.

Claim 5

A muffler as set forth in claim 3 wherein said gas flow means comprises a tube having a perforated wall opening into said fourth chamber to provide means for attenuation of frequencies higher than said broad band.

Claim 6

A muffler comprising an elongated housing having an inlet and an outlet, an inlet gas flow tube in said housing connected to said inlet and an outlet gas flow tube in said housing connected to said outlet, at least two transverse partitions in said housing subdividing it into at least three transverse chambers, one of said chambers comprising a first expansion chamber and another of said chambers comprising a second expansion chamber, first means connecting said inlet tube with said first expansion chamber so that gas from the inlet tube flows into the first expansion chamber, second means connecting said outlet tube with said second expansion chamber so that gas in the second expansion chamber flows into the outlet tube, and a substantially imperforate intermediate tube supported by said partitions having a predetermined length and having an inlet end opening into the first expansion chamber and an outlet end opening into the second expansion chamber to provide a path for gas flow from the first to the second expansion chamber, said first means and the inlet end of said intermediate tube forming the only ports for the first expansion chamber and the second means and the outlet end of the intermediate tube forming the only substantial flow ports for the second expansion chamber, the length of said intermediate tube along with the length of the expansion chambers and the ratio of the areas of the chambers and intermediate tube being selected to tune said chambers and tube to attenuate a broad band of sound frequencies having a substantially predetermined cutoff frequency at the low end of the band, said third transverse chamber being located between said first and second transverse chambers and forming a part of one of said first and second means.

Claim 7

A muffler comprising an elongated housing having an inlet and an outlet, an inlet gas flow tube in said housing connected to said inlet and an outlet gas flow tube in said housing connected to said outlet, at least two transverse partitions in said housing subdividing it into at least three transverse chambers, one of said chambers comprising a first expansion chamber and another of said chambers comprising a second expansion chamber, first means connecting said inlet tube with said first expansion chamber so that gas from the inlet tube flows into the first expansion chamber, second means connecting said outlet tube with said second expansion chamber so that gas in the second expansion chamber flows into the outlet tube, and a substantially imperforate intermediate tube supported by said partitions having a predetermined length and having an inlet end opening into the first expansion chamber and an outlet end opening into the second expansion chamber to provide a path for gas flow from the first to the second expansion chamber, said first means and the inlet end of said intermediate tube forming the only ports for the first expansion chamber and the second means and the outlet end of the intermediate tube forming the only substantial flow ports for the second expansion chamber, the length of said intermediate tube along with the length of the expansion chambers and the ratio of the areas of the chambers and intermediate tube being selected to tune said chambers and tube to attenuate a broad band of sound frequencies having a substantially predetermined cutoff frequency at the low end of the band, said third transverse chamber being located between said first and second transverse chambers and forming a part of one of said first and second means.

Claim 8

A muffler as set forth in claim 5 wherein said outlet tube has an inlet opening into said third transverse chamber whereby said third transverse chamber forms a part of said second means.

Claim 9

A muffler as set forth in claim 6 including a third transverse partition acting with said two transverse partitions to form a fourth transverse chamber in said housing, said fourth transverse chamber being located between said second expansion chamber and said third transverse chamber and including gas flow means connecting said second expansion chamber and said third transverse chamber, said gas flow means forming a part of said second means.

Claim 10

A muffler as set forth in claim 7 wherein said gas flow means comprises a tube having a perforated wall opening into said fourth chamber to provide means for attenuation of frequencies higher than said broad band.

Claim 11

A muffler as set forth in claim 8 wherein said outlet tube has a perforated wall opening into said fourth chamber to provide for by-pass flow of gas and to provide means to attenuate sound frequencies higher than said broad band.

Claim 12

A muffler as set forth in claim 9 wherein the outlet end of said inlet tube opens into the first expansion chamber to form said first means.

Claim 13

A muffler as set forth in claim 10 including a fourth transverse partition forming a fifth transverse chamber, said inlet tube extending through said fifth chamber and having a wall therein with aperture means opening into the chamber and forming the only connection of said chamber with gas flowing through the muffler whereby said fifth chamber and aperture means form a resonator chamber tuned to attenuate a predetermined frequency.

Claim 14

A muffler as set forth in claim 9 including a fourth transverse partition forming a fifth transverse chamber located between said first and second expansion chambers, said inlet tube having an outlet opening into said fifth chamber and said fifth chamber having gas flow means connecting it with the first expansion chamber and forming a part of said first means.

Claim 15

A muffler comprising an elongated housing having an inlet and an outlet, an inlet gas flow tube in said housing connected to said inlet and an outlet gas flow tube in said housing connected to said outlet, at least two transverse partitions in said housing subdividing it into at least three transverse chambers, one of said chambers comprising a first expansion chamber and another of said chambers comprising a second expansion chamber, first means connecting said inlet tube with said first expansion chamber so that gas from the inlet tube flows into the first expansion chamber, second means connecting said outlet tube with said second expansion chamber so that gas in the second expansion chamber flows into the outlet tube, and a substantially imperforate intermediate tube supported by said partitions having a predetermined length and having an inlet end opening into the first expansion chamber and an outlet end opening into the second expansion chamber to provide a path for gas flow from the first to the second expansion chamber, the length of said intermediate tube along with the length of the expansion chambers and the ratio of the areas of the chambers and intermediate tube being selected to tune said chambers and tube to attenuate a broad band of sound frequencies having a substantially predetermined cutoff frequency at the low end of the band, said third transverse chamber being located between said first and second expansion chambers and said intermediate tube being substantially longer than said third chamber and extending through said third chamber and overlapping the inlet and outlet gas flow tubes in said first and second chambers, said inlet and outlet tubes each extending through said third chamber and having aperture means in the walls thereof opening into said third chamber to provide for by-pass flow of gas and to provide said means to attenuate sound frequencies higher than said broad band.

Claim 16

A muffler comprising an elongated housing having an inlet and an outlet, an inlet gas flow tube in said housing connected to said inlet and an outlet gas flow tube in said housing connected to said outlet, at least two transverse partitions in said housing subdividing it into at least three transverse chambers, one of said chambers comprising a first expansion chamber and another of said chambers comprising a second expansion chamber, first means connecting said inlet tube with said first expansion chamber so that gas from the inlet tube flows into the first expansion chamber, second means connecting said outlet tube with said second expansion chamber so that gas in the second expansion chamber flows into the outlet tube, and a substantially imperforate intermediate tube supported by said partitions having a predetermined length and having an inlet end opening into the first expansion chamber and an outlet end opening into the second expansion chamber to provide a path for gas flow from the first to the second expansion chamber, the length of said intermediate tube along with the length of the expansion chambers and the ratio of the areas of the chambers and intermediate tube being selected to tune said chambers and tube to attenuate a broad band of sound frequencies having a substantially predetermined cutoff frequency at the low end of the band, said third transverse chamber being located between said first and second expansion chambers and said intermediate tube being substantially longer than said third chamber and extending through said third chamber and overlapping the inlet and outlet gas flow tubes in said first and second chambers, said inlet and outlet tubes each extending through said third chamber and having aperture means in the walls thereof opening into said third chamber to provide for by-pass flow of gas and to provide said means to attenuate sound frequencies higher than said broad band.