Patent US3633459A successfully refreshed from Google Patents.
US3633459A
Expired / Lapsed
US
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Pneumatic percussion device
Assignee: Individual
•
Filing: 1970-02-16
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Granted: 1972-01-11
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Expires: 1990-02-16
Abstract
Abstract In a pneumatically operated percussion device, a working cylinder with a differential-type piston reciprocable therein is in constant communication with a compressed-air reservoir to cause the driving stroke. The piston is cup-shaped with an open lower end and has a cylindrical sleeve for engaging an annular chamber in the working cylinder. The bottom wall of the cylinder has an outlet for venting air from the cylinder to the atmosphere during the driving stroke. In the initial position of the piston, the annular chamber communicates with an air supply line, and during the driving stroke of the piston the annular chamber is vented. At the completion of the driving stroke a venting valve in the piston is opened, and air from the supply line is admitted to the annular chamber to return the piston to its initial position.
Inventors
- 👤 Lange Wilfried
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 07:40
CPC Classifications
B; B25; B25C; B25C1/00; B25C1/04; B25C1/041
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
112 words
In a pneumatically operated percussion device comprising a body portion containing a cylinder having a sidewAll and a bottom wall at one end thereof, a cup-shaped differential-type piston in said cylinder, said body portion defining an air reservoir around said cylinder, said air reservoir being in permanent communication with the opposite end of said cylinder, a tubular member in said cylinder carried by the bottom wall and defining with said sidewall an annular air chamber, said piston having an annular clearance for receiving said tubular member, an air admission chamber, and valve means for admitting compressed air from said air admission chamber to said annular air chamber and to said air reservoir.
Claim 2
Dependent Claim
112 words
In a pneumatically operated percussion device comprising a body portion containing a cylinder having a sidewAll and a bottom wall at one end thereof, a cup-shaped differential-type piston in said cylinder, said body portion defining an air reservoir around said cylinder, said air reservoir being in permanent communication with the opposite end of said cylinder, a tubular member in said cylinder carried by the bottom wall and defining with said sidewall an annular air chamber, said piston having an annular clearance for receiving said tubular member, an air admission chamber, and valve means for admitting compressed air from said air admission chamber to said annular air chamber and to said air reservoir.
Claim 3
Dependent Claim
54 words
The device of claim 1 wherein said cup-shaped differential-type piston comprises a lower cylindrical sleeve, said sleeve being guided within and sealed against said annular air chamber, said sidewall of said cylinder having ports and check valve means closing said ports so that said air reservoir may be filled from said annular air chamber.
Claim 4
Dependent Claim
53 words
The device of claim 1 wherein vent valve means is arranged in said differential-type piston, said vent valve means having a valve rod which at the end of the driving stroke of said piston abuts the cylinder bottom wall, whereby said vent valve means is opened to enable a return of the piston.
Claim 5
Dependent Claim
30 words
The device of claim 1 wherein a valve assembly comprising a manually operable control valve is mounted in a passage connecting said air admission chamber with said annular air chamber.
Claim 6
Dependent Claim
21 words
The device of claim 1 wherein a spring-loaded ball valve is disposed between said air admission chamber and said air reservoir.
Claim 7
Dependent Claim
28 words
The device of claim 1 wherein a cover of said body portion comprises a cylindrical recess for receiving said cup-shaped differential-type piston when in its initial retracted position.
Claim 8
Dependent Claim
31 words
The device of claim 6, wherein said piston is provided with a bore for venting the air from said cylindrical recess which is displaced by the piston on its return stroke.
References Cited (Backward Citations)
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US2960067A
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US3147670A
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US3361036A
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US3479926A
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US3512454A
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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) | 1975-01-10 | 1975-07-12 | 1976-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-10 | 1979-07-12 | 1980-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-10 | 1983-07-12 | 1984-01-11 | $7700.00 | Window Closed / Lapsed |