Patent US3636707A successfully refreshed from Google Patents.
US3636707A
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: 1972-01-25
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Expires: 1990-07-22
Abstract
Abstract A pressure fluid power device for operating handtools having a power reservoir in which a compressible fluid, such as a gas, is maintained under pressure and is employed to impart movement to or actuate, a suitable driving means, such as a drive piston or hammer of a power handtool, through a linkage of a noncompressible driving fluid. The invention further relates to cooperable means for slowing or braking the movement of the drive piston as it approaches its fully extended position to minimize shocks to the body of the device; sealing means within the device; and automatic means for limiting the amount of retraction of the drive piston.
Inventors
- 👤 Oliver E Saari
- 👤 Henry Pomernacki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 13:41
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: 13
Claim 1
Independent Claim
229 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, said 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, brake means encircling said drive piston and adapted to cushion said drive piston when said biasing means forces the drive piston to its extended position, seal means cooperatively engaging when said accumulator piston engages said drive piston, passage means for introducing said power fluid through said brake means into contact with said drive piston and accumulator piston and coengageable resilient stop means on said body and said drive piston for limiting movement of said drive piston to the retracted position.
Claim 2
Dependent Claim
229 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, said 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, brake means encircling said drive piston and adapted to cushion said drive piston when said biasing means forces the drive piston to its extended position, seal means cooperatively engaging when said accumulator piston engages said drive piston, passage means for introducing said power fluid through said brake means into contact with said drive piston and accumulator piston and coengageable resilient stop means on said body and said drive piston for limiting movement of said drive piston to the retracted position.
Claim 3
Dependent Claim
68 words
A device of the type claimed in claim 1 wherein said drive piston includes an enlarged portion defining the end portion extending into said cylinder, said brake means presenting a recessed counterbore complementary to and encircling a substantial portion of said enlarged portion of said drive piston, said recess being coaxial with a bore in said brake means adapted to accept said drive piston in complementary telescoping relationship.
Claim 4
Dependent Claim
113 words
A device of the type claimed in claim 2 wherein said brake means is an annular member positioned within said body between said bore and said cylinder, said brake means having a pass through bore complementary to said drive piston with said pass-through bore being slightly larger than said drive piston through a substantial portion of the length of said drive piston except for said enlarged portion whereby said power fluid can be introduced through said pass through bore into said recess to act upon the enlarged portion of said drive piston, means provided for passage of said power fluid to a position in which it is capable of engaging the accumulator piston.
Claim 5
Dependent Claim
222 words
A device of the type claimed in claim 2 wherein said body is recessed between said bore and said cylinder to accept said brake means, said brake means including an annular bushing having a central pass-through bore adapted to complementarily telescopically accept a substantial portion of said drive piston, said enlarged end portion of said drive piston being Substantially cylindrical and having a predetermined axial dimension and connected to the balance of the drive piston by a frustoconical and radiused section, said recess in said brake having a cylindrical wall slightly larger than the cylindrical portion of said enlarged end portion and having an axial dimension less than said predetermined enlarged end portion dimension, the base of said recess being tapered complementary to the connecting section of said enlarged end portion, said base communicating with the pass-through bore in said brake means, passage means located between said brake and said body portion to permit flow of said power fluid through said pass-through bore between said drive piston and said brake into engagement with the enlarged end portion, lateral passage means extending axially between said brake and said body means to permit passage of said power fluid into said cylinder for application of forces against said accumulator piston to thereby simultaneously move said drive piston and said accumulator piston against said biasing force.
Claim 6
Dependent Claim
49 words
A device of the type claimed in claim 4 wherein the passage means are defined by a plurality of radially extending grooves in the base of said brake means and said lateral passage means are defined by the removal of segments of the annular sidewall of said brake means.
Claim 7
Dependent Claim
120 words
A device of the type claimed in claim 5 wherein said brake means is further defined by an axially extending flange coaxial with said recess having an inner wall identifying the same circle as the balance of the brake wall complementary to said enlarged end portion, said axially extending flange being defined on its outer surface by a frustoconical configuration, said cylinder having a frustoconical configuration laterally spaced from said axially extending flange and said body means adjacent said frustoconical section having passage means communicating with the lateral passage means of said brake means whereby said power fluid is vectorially directed against said accumulator piston and the adjacent axial portion of the enlarged end portion contacted by said accumulator piston.
Claim 8
Dependent Claim
59 words
A device of the type claimed in claim 2 wherein said enlarged end portion of said drive piston is provided with a recess defined by an upstanding sidewall, said accumulator piston at its end adjacent said drive piston being provided with a complementary protuberance adapted to partially fill the recess in said enlarged end portion of the drive piston.
Claim 9
Dependent Claim
45 words
A device of the type claimed in claim 7 wherein said upstanding wall portion is defined on its inner diameter by a frustoconical configuration while said accumulator piston protuberance means on its outer peripheral surface defines a configuration adapted to sealingly engage said inner diameter.
Claim 10
Dependent Claim
73 words
A device of the type claimed in claim 2 wherein said drive piston intermediate its extremity is provided with a groove defining a shoulder facing towards said enlarged end portion, said resilient stop means including spring urged means adapted to engage said drive piston during its movement from extended to retracted positions and to engage said shoulder means to prevent further movement of said drive piston in the direction of the retracted position.
Claim 11
Dependent Claim
21 words
A device of the type claimed in claim 9 wherein said resilient stop means includes one or more hinged spring-loaded fingers.
Claim 12
Dependent Claim
54 words
A device of the type claimed in claim 10 wherein said spring-loaded fingers are two in number disposed on opposite sides of the axis of said drive piston, said fingers having complementarily shaped end portions for cooperation with said shoulder means on said drive piston and being urged into engagement by leaf spring members.
Claim 13
Dependent Claim
24 words
A device of the type claimed in claim 10 wherein said resilient stop means include shoulder detent means spring-urged into engagement with said shoulder.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-24 | 1975-07-26 | 1976-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-24 | 1979-07-26 | 1980-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-24 | 1983-07-26 | 1984-01-25 | $7700.00 | Window Closed / Lapsed |