Patent US1394841A successfully refreshed from Google Patents.
Patent US3811531A successfully refreshed from Google Patents.
US3811531A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Silencer
Assignee: Safety Vehicles Development AB
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Filing: 1972-12-05
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Granted: 1974-05-21
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Expires: 1992-12-05
Abstract
Abstract A muffler or silencer, preferably for motor vehicles, adapted to be mounted to the exhaust pipe of an exhaust gas system. The silencer comprises a casing having arranged therein a number of means arranged to impede the passage of a major part of the gas flow and to re-direct said part gas flow rearwardly. Gas throughflow openings are provided at alternate ends of the gas flow redirecting means, between said ends and the casing walls. The arrangement of the through-flow openings is such as to force the gas flow to follow a zig-zag path, and baffle means may be arranged, if desired. The whole device may be made from a heat resistant plastics material.
Inventors
- 👤 J Forssman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:26
CPC Classifications
F; F01; F01N; F01N1/00; F01N1/08; F01N1/083; F01N1/082; F01N1/10
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
365 words
A silencer for motor vehicles, comprising a casing of glass fiber reinforced, heat resistant polyester plastics and having rectangular cross section, said casing forming a tubular body having end walls at its ends and an inlet at one end and an outlet at the other end of said casing, a first and a second acoustic chamber being located between a pair of axially spaced baffle walls of plastics material, each of said baffle walls being perforated in a predetermined area to admit through-flow of gases, said baffle walls being integral with the casing and mounted in spaced relationship to the respective end wall to define an inlet chamber and an outlet chamber respectively, at least one of the acoustic chambers containing sound absorbing material, a number of rigid partition walls of plastics material being integral with the walls of the casing and guiding the gas flow in a predetermined path between the two acoustic chambers, each partition wall extending between and being connected to two opposite walls of the casing and being connected at one end to one of the other two opposite casing walls and being disposed outside said sound absorbing material, whereas the opposite end of the partition wall forms a straight edge located in spaced relationship to the adjacent casing wall to form a through-flow opening, said through-flow openings being located alternately at opposite sides of the longitudinal axis of the casing to provide a zigzag flow of gases through the casing, each partition wall having a generally curved cross section with its concave side facing the inlet end of the casing and comprising a leg portion connected at its one end to the casing and merging at its other end into a reversing partition wall portion directed generally towards the inlet end of the casing to provide a pocket for locally redirecting the flow before it passes the free edge of the partition wall and thereafter again is redirected to enter into the adjacent through-flow opening, said perforated areas of said baffle walls being offset relative to the lengthwise axis of the casing to provide in each acoustic chamber an oblique flow path smoothly connected to the said zigzag flow path.
Claim 2
Dependent Claim
365 words
A silencer for motor vehicles, comprising a casing of glass fiber reinforced, heat resistant polyester plastics and having rectangular cross section, said casing forming a tubular body having end walls at its ends and an inlet at one end and an outlet at the other end of said casing, a first and a second acoustic chamber being located between a pair of axially spaced baffle walls of plastics material, each of said baffle walls being perforated in a predetermined area to admit through-flow of gases, said baffle walls being integral with the casing and mounted in spaced relationship to the respective end wall to define an inlet chamber and an outlet chamber respectively, at least one of the acoustic chambers containing sound absorbing material, a number of rigid partition walls of plastics material being integral with the walls of the casing and guiding the gas flow in a predetermined path between the two acoustic chambers, each partition wall extending between and being connected to two opposite walls of the casing and being connected at one end to one of the other two opposite casing walls and being disposed outside said sound absorbing material, whereas the opposite end of the partition wall forms a straight edge located in spaced relationship to the adjacent casing wall to form a through-flow opening, said through-flow openings being located alternately at opposite sides of the longitudinal axis of the casing to provide a zigzag flow of gases through the casing, each partition wall having a generally curved cross section with its concave side facing the inlet end of the casing and comprising a leg portion connected at its one end to the casing and merging at its other end into a reversing partition wall portion directed generally towards the inlet end of the casing to provide a pocket for locally redirecting the flow before it passes the free edge of the partition wall and thereafter again is redirected to enter into the adjacent through-flow opening, said perforated areas of said baffle walls being offset relative to the lengthwise axis of the casing to provide in each acoustic chamber an oblique flow path smoothly connected to the said zigzag flow path.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-05-20 | 1977-11-19 | 1978-05-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-20 | 1981-11-19 | 1982-05-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-20 | 1985-11-19 | 1986-05-21 | $7700.00 | Window Closed / Lapsed |