US3667222A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Power device
Assignee: Illinois Tool Works Inc
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Filing: 1970-07-22
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Granted: 1972-06-06
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Expires: 1990-07-22
Abstract
Abstract A power device having a power reservoir in which a compressible fluid is maintained under pressure, an accumulator piston and a drive piston which are simultaneously movable to retracted or cocked positions by the introduction of a non-compressible power fluid into a cylinder in which the pistons are reciprocably movable, the power fluid acting on exposed areas of the drive piston to move it with the accumulator piston until it reaches its fully cocked position whereupon further movement of the accumulator piston exposes additional areas of the drive piston to the pressure of the power fluid whereby the compressible fluid, acting through the power fluid, imparts drive movement to the drive piston and multiple seal means on said accumulator piston, reservoir means in said accumulator piston to trap any power fluid which has by-passed one of said seals to thereby avoid intermixing of said compressible and non-compressible fluids.
Inventors
- 👤 Oliver E Saari
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 06:06
CPC Classifications
F; F15; F15B; F15B11/00; F15B11/06; F15B11/072; F15B11/0725; B; B25; B25C; B25C1/00; B25C1/001; B25C1/005; B25C1/04; B25C1/048; F15B2211/00; F15B2211/70; F15B2211/71; F15B2211/7114; F15B2211/7128
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
205 words
A power device including: a body having a bore; a drive piston reciprocably movable in said bore, said piston having one end portion extendable outwardly of said bore, said body having means providing a cylinder, said drive piston having an end portion opposite said one end portion extending into said cylinder; an accumulator piston reciprocably movable in said cylinder; means biasing said accumulator piston toward said drive piston and into engagement therewith; means for introducing a noncompressible power fluid into said cylinder for moving said drive piston and said accumulator piston toward retracted positions against the force exerted by said biasing means, sad accumulator piston shielding a predetermined area of said drive piston from the force of the pressure of said power fluid when said accumulator piston is in engagement therewith, said drive piston having a smaller total area thereof exposed to said power fluid than said accumulator piston, said accumulator piston including seal means at opposite ends thereof in encircling relationship to contact the wall of said cylinder, port means intermediate the position of said seal members communicating with an internal recess within said accumulator piston, adapted to capture any power fluid which by-passes the first seal means positioned closest to the drive piston.
Claim 2
Dependent Claim
205 words
A power device including: a body having a bore; a drive piston reciprocably movable in said bore, said piston having one end portion extendable outwardly of said bore, said body having means providing a cylinder, said drive piston having an end portion opposite said one end portion extending into said cylinder; an accumulator piston reciprocably movable in said cylinder; means biasing said accumulator piston toward said drive piston and into engagement therewith; means for introducing a noncompressible power fluid into said cylinder for moving said drive piston and said accumulator piston toward retracted positions against the force exerted by said biasing means, sad accumulator piston shielding a predetermined area of said drive piston from the force of the pressure of said power fluid when said accumulator piston is in engagement therewith, said drive piston having a smaller total area thereof exposed to said power fluid than said accumulator piston, said accumulator piston including seal means at opposite ends thereof in encircling relationship to contact the wall of said cylinder, port means intermediate the position of said seal members communicating with an internal recess within said accumulator piston, adapted to capture any power fluid which by-passes the first seal means positioned closest to the drive piston.
Claim 3
Dependent Claim
50 words
A device of the type claimed in claim 1 wherein said recess means communicates with the end of the accumulator piston opposite to the end in engagement with said drive piston, means closing said recess means adjacent its open end to prevent communication with said bias means in said cylinder.
Claim 4
Dependent Claim
56 words
A device of the type claimed in claim 2 wherein said means closing said recess is a secondary piston movable within said recess and communicating with said biasing means to form with said recess a variable reservoir for power fluid which by-passes the seal nearest the drive piston and thereby removes pressure against the second seal.
Claim 5
Dependent Claim
36 words
A device of the type claimed in claim 3 wherein said biasing means is a compressed gas, suitable aperture means closing the end of said recess and limiting movement of the secondary piston within the recess.
Claim 6
Dependent Claim
201 words
A device of the type claimed in claim 1 wherein said accumulator piston is provided with a pair of spaced annular sealing members, sealing means at one end of said accumulator piston for cooperative engagement with said drive piston, recess means opening through the end of said accumulator piston opposite to said piston cooperative sealing means, port means opening laterally through said accumulator piston and positioned intermediate said annular sealing members and further communicating with said recess, secondary piston means positioned within said recess, apertured means adjacent the open end of said recess for restricting outward movement of said secondary piston, said biasing means acting on said secondary piston through said apertured closure means at the second end of said accumulator piston recess, whereby power fluid by-passing the annular seal means positioned adjacent the end of said accumulator piston in contact with said drive piston will flow into said recess through said port means, said secondary piston maintaining said power fluid under pressure by the biasing means, the area of said secondary piston being less than the accumulator piston and thereby lessening the possibility of power fluid by-passing the second annular seal of the accumulator piston to contaminate the biasing means.
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) | 1975-06-06 | 1975-12-06 | 1976-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-06 | 1979-12-06 | 1980-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-06 | 1983-12-06 | 1984-06-06 | $7700.00 | Window Closed / Lapsed |