US3635299A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Muffler for pneumatic tool
Assignee: Gardner Denver Inc
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Filing: 1970-04-20
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Granted: 1972-01-18
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Expires: 1990-04-20
Abstract
Abstract A muffler for a pneumatic tool of the expansible chamber percussion motor type. The muffler comprises a substantially integral shroud covering a portion of the tool casing and forming a double expansion chamber for the motive air exhausting from the percussion motor. The muffler shroud includes a plurality of openings for discharging exhaust air from the expansion chamber. Exhaust ports opening from the percussion motor into the double expansion chamber are arranged with respect to the exhaust openings in the shroud to provide substantial retroverted flow of the exhaust air upon entering and leaving the muffler. An exhaust flow stream from the percussion motor distributing valve is also introduced into one of the muffler expansion chambers and interacts with the percussion motor exhaust air to produce a synergistic noise reduction effect.
Inventors
- 👤 Roy J Hayes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:36
CPC Classifications
B; B25; B25D; B25D17/00; B25D17/11; B25D17/12; Y; Y10; Y10S; Y10S173/00; Y10S173/02
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
149 words
In a pneumatic percussion tool: a casing forming a cylinder; a hammer piston reciprocably disposed in said cylinder and forming therewith expansible chamber means; a motive air distributing valve having a shiftable valve elemeNt for valving quantities of motive air to said cylinder; a muffler shroud disposed about the exterior of said casing in spaced relationship thereto; means dividing said space between said muffler shroud and said casing into first and second expansion chambers, said means forming an orifice interconnecting said first and second expansion chambers; exhaust port means opening from said cylinder into said first expansion chamber; exhaust openings in said shroud communicating said second expansion chamber with the exterior of said muffler; and, exhaust port means for said distributing valve opening into one of said expansion chambers for exhausting quantities of motive air directly into said one chamber in response to the shifting of said valve element.
Claim 2
Dependent Claim
149 words
In a pneumatic percussion tool: a casing forming a cylinder; a hammer piston reciprocably disposed in said cylinder and forming therewith expansible chamber means; a motive air distributing valve having a shiftable valve elemeNt for valving quantities of motive air to said cylinder; a muffler shroud disposed about the exterior of said casing in spaced relationship thereto; means dividing said space between said muffler shroud and said casing into first and second expansion chambers, said means forming an orifice interconnecting said first and second expansion chambers; exhaust port means opening from said cylinder into said first expansion chamber; exhaust openings in said shroud communicating said second expansion chamber with the exterior of said muffler; and, exhaust port means for said distributing valve opening into one of said expansion chambers for exhausting quantities of motive air directly into said one chamber in response to the shifting of said valve element.
Claim 3
Dependent Claim
44 words
The invention set forth in claim 1 wherein: said distributing valve exhaust port means is arranged to direct exhaust air flowing therefrom into said second expansion chamber in a direction substantially opposing the flow of exhaust air from said cylinder passing through said orifice.
Claim 4
Dependent Claim
132 words
In a pneumatic percussion tool: a casing forming a cylinder; a hammer piston reciprocably disposed in said cylinder and forming therewith expansible chamber means; a motive air distributing valve having a shiftable valve element for valving quantities of motive air to said cylinder; a muffler shroud disposed about the exterior of said casing in spaced relationship thereto and forming expansion chamber means between said muffler shroud and said casing; exhaust port means opening from said cylinder into said expansion chamber means; exhaust openings in said shroud communicating said expansion chamber means with the exterior of said muffler; and, exhaust port means for said distributing valve opening into said expansion chamber means for exhausting quantities of motive air directly into said expansion chamber means in response to the shifting of said valve element.
Claim 5
Dependent Claim
132 words
In a pneumatic percussion tool: a casing forming a cylinder; a hammer piston reciprocably disposed in said cylinder and forming therewith expansible chamber means; a motive air distributing valve having a shiftable valve element for valving quantities of motive air to said cylinder; a muffler shroud disposed about the exterior of said casing in spaced relationship thereto and forming expansion chamber means between said muffler shroud and said casing; exhaust port means opening from said cylinder into said expansion chamber means; exhaust openings in said shroud communicating said expansion chamber means with the exterior of said muffler; and, exhaust port means for said distributing valve opening into said expansion chamber means for exhausting quantities of motive air directly into said expansion chamber means in response to the shifting of said valve element.
Claim 6
Dependent Claim
131 words
In a pneumatic percussion tool: a casing forming a cylinder; a hammer piston reciprocably disposed in said cylinder and forming therewith expansible chamber means; a muffler shroud disposed about the exterior of said casing in spaced relationship thereto; means dividing said space between said muffler shroud and said casing into first and second expansion chambers; exhaust port means opening from said cylinder into one of said expansion chambers; exhaust openings in said shroud communicating the other of said expansion chambers with the exterior of said muffler; and, an orifice formed by said means dividing said space and interconnecting said first and second expansion chambers, said orifice having a flow area in the range of three to four times the total flow area of said exhaust port means opening from said cylinder.
Claim 7
Dependent Claim
131 words
In a pneumatic percussion tool: a casing forming a cylinder; a hammer piston reciprocably disposed in said cylinder and forming therewith expansible chamber means; a muffler shroud disposed about the exterior of said casing in spaced relationship thereto; means dividing said space between said muffler shroud and said casing into first and second expansion chambers; exhaust port means opening from said cylinder into one of said expansion chambers; exhaust openings in said shroud communicating the other of said expansion chambers with the exterior of said muffler; and, an orifice formed by said means dividing said space and interconnecting said first and second expansion chambers, said orifice having a flow area in the range of three to four times the total flow area of said exhaust port means opening from said cylinder.
Claim 8
Dependent Claim
33 words
The invention set forth in claim 4 wherein: said exhaust openings in said shroud have a total flow area in the range of three to four times the flow area of said orifice.
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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) | 1975-01-17 | 1975-07-19 | 1976-01-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-17 | 1979-07-19 | 1980-01-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-17 | 1983-07-19 | 1984-01-18 | $7700.00 | Window Closed / Lapsed |