US3656560A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic shut-off valve for power tool
Assignee: Ingersoll Rand Co
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Filing: 1970-09-29
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Granted: 1972-04-18
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Expires: 1990-09-29
Abstract
Abstract A fluid-actuated shut-off valve for a fluid-powered tool such as a wrench including a spool valve urged to open position by a spring and having respective valve-operating surfaces subject to both inlet and exhaust pressures in the tool. The valve operating surfaces and spring are arranged so the valve is thrown to its closed position by a combination of the rise in inlet pressure and the drop in exhaust pressure as the tool motor slows down and stalls under load.
Inventors
- 👤 Robert J Catterfeld
- 👤 David W Tibbott
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 20:11
CPC Classifications
B; B25; B25B; B25B23/00; B25B23/14; B25B23/145
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
145 words
A fluid driven power tool including: a casing containing a motor, an inlet passageway for feeding motive fluid to said motor and an exhaust passageway for exhausting fluid from said motor; a fluid-actuated valve located in said inlet passageway and movable between alternate positions including an open position allowing motive fluid to flow to said motor and a closed position preventing motive fluid from flowing to said motor; first valve-operating means urging said valve to its closed position; second valve-operating means communicating with said exhaust passageway and operative, when subject to fluid pressure, to urge said valve to its open position against the force of said first valve-operating means; and said first and second valve-operating means being arranged so that said valve will move to its closed position in response to the drop in fluid pressure in said exhaust passageway when said motor slows down.
Claim 2
Dependent Claim
145 words
A fluid driven power tool including: a casing containing a motor, an inlet passageway for feeding motive fluid to said motor and an exhaust passageway for exhausting fluid from said motor; a fluid-actuated valve located in said inlet passageway and movable between alternate positions including an open position allowing motive fluid to flow to said motor and a closed position preventing motive fluid from flowing to said motor; first valve-operating means urging said valve to its closed position; second valve-operating means communicating with said exhaust passageway and operative, when subject to fluid pressure, to urge said valve to its open position against the force of said first valve-operating means; and said first and second valve-operating means being arranged so that said valve will move to its closed position in response to the drop in fluid pressure in said exhaust passageway when said motor slows down.
Claim 3
Dependent Claim
179 words
A fluid driven power tool including: a casing containing a motor, an inlet passageway for feeding motive fluid to said motor and an exhaust passageway for exhausting fluid from said motor; a fluid-actuated valve located in said inlet passageway and movable between alternate positions including an open position allowing motive fluid to flow to said motor and a closed position preventing motive fluid from flowing to said motor; spring means in said casing urging said valve to said open position; first valve-operating means communicating with said inlet passageway and operative, when subject to fluid pressure to urge said valve to its closed position against the force of said spring means; second valve-operating means communicating with said exhaust passageway and operative, when subject to fluid pressure, to urge said valve to its open position against the force of said first valve-operating means; and said spring means, first and second valve-operating means being arranged so that said valve will move to its closeD position in response to the drop in fluid pressure in said exhaust passageway when said motor slows down.
Claim 4
Dependent Claim
179 words
A fluid driven power tool including: a casing containing a motor, an inlet passageway for feeding motive fluid to said motor and an exhaust passageway for exhausting fluid from said motor; a fluid-actuated valve located in said inlet passageway and movable between alternate positions including an open position allowing motive fluid to flow to said motor and a closed position preventing motive fluid from flowing to said motor; spring means in said casing urging said valve to said open position; first valve-operating means communicating with said inlet passageway and operative, when subject to fluid pressure to urge said valve to its closed position against the force of said spring means; second valve-operating means communicating with said exhaust passageway and operative, when subject to fluid pressure, to urge said valve to its open position against the force of said first valve-operating means; and said spring means, first and second valve-operating means being arranged so that said valve will move to its closeD position in response to the drop in fluid pressure in said exhaust passageway when said motor slows down.
Claim 5
Dependent Claim
54 words
The power tool of claim 2 wherein: said valve is a spool valve reciprocating in a bore provided in said casing; and said first valve-operating means includes a first chamber formed in part by one end of said valve, pressure in said first chamber being operative to urge said valve toward a closed position.
Claim 6
Dependent Claim
21 words
The power tool of claim 3 wherein: said first chamber includes a cavity provided in said one end of said valve.
Claim 7
Dependent Claim
32 words
The power tool of claim 4 wherein: said first chamber communicates with said inlet passageway by a restricted passage which reduces the speed in which pressure can change in said first chamber.
Claim 8
Dependent Claim
62 words
The power tool of claim 5 wherein: said restricted passage includes a port which is substantially closed by said valve when in its fully open position and open when said valve is in its closed position, the clearance between said valve and its bore being enough to allow pressure to leak into said first chamber from said port at a controlled rate.
Claim 9
Dependent Claim
40 words
The power tool of claim 3 wherein: said second valve-operating means is a second chamber formed in part by the other end of said valve, pressure in said second chamber being operative to urge said valve towards its open position.
Claim 10
Dependent Claim
22 words
The power tool of claim 7 wherein: said second chamber includes a cavity provided in said other end of said valve spool.
Claim 11
Dependent Claim
28 words
The power tool of claim 8 wherein: said spring is located in said second chamber; and means is in said casing for adjusting the tension on said spring.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-04-18 | 1975-10-18 | 1976-04-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-18 | 1979-10-18 | 1980-04-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-18 | 1983-10-18 | 1984-04-18 | $7700.00 | Window Closed / Lapsed |