US4411436A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spring loaded piston seal assembly
Assignee: United States Department of the Army
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Filing: 1982-04-05
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Granted: 1983-10-25
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Expires: 2002-04-05
Abstract
Abstract Spring loaded seals comprised of two resting rings positioned in an annular groove of a piston that are pressed against the upper and lower shoulders of the groove by a corrugated spring fitted therebetween. Each resting ring has at least one free-floating sealing wedge, preferably made of ceramic material, which overlaps the outer peripheral edge thereof for sliding along the cylinder wall wherein the sealing wedges frictionally press against the cylinder wall during the stroke of the piston in one direction and release to more freely slide along the cylinder wall in the other direction. The resting rings and sealing wedges form dry seals, i.e. unlubricated sliding seals, for use in compressor devices which operate at either high or low temperatures.
Inventors
- 👤 Peter Durenec
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 08:55
CPC Classifications
F; F16; F16J; F16J9/00; F16J9/28; F16J9/06; F16J9/061; F16J9/063
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
115 words
A spring loaded piston seal assembly comprising: a plurality of annular grooves around the upper portion of said piston; a dry seal means within each of said plurality of annular grooves comprised of two resting rings having at least one beveled edge on the outer periphery and a labyrinth seal on its annular seating region which fits into the base of said plurality of annular grooves and having a free-floating sealing wedge form fitted into each of the beveled edges for sliding along a cylinder wall; and a spring biasing means positioned between said two resting rings which biases said two resting rings against the upper and lower shoulders of said plurality of annular grooves.
Claim 2
Dependent Claim
115 words
A spring loaded piston seal assembly comprising: a plurality of annular grooves around the upper portion of said piston; a dry seal means within each of said plurality of annular grooves comprised of two resting rings having at least one beveled edge on the outer periphery and a labyrinth seal on its annular seating region which fits into the base of said plurality of annular grooves and having a free-floating sealing wedge form fitted into each of the beveled edges for sliding along a cylinder wall; and a spring biasing means positioned between said two resting rings which biases said two resting rings against the upper and lower shoulders of said plurality of annular grooves.
Claim 3
Dependent Claim
19 words
A seal assembly as set forth in claim 1 wherein said plurality of annular grooves is one annular groove.
Claim 4
Dependent Claim
23 words
A seal assembly as set forth in claim 2 wherein said beveled edge into which said sealing wedge is fitted is about 90°.
Claim 5
Dependent Claim
42 words
A seal assembly as set forth in claim 3 wherein said spring biasing means is a circular corrugated spring having cylindrical ridges and hollows that bias said two resting rings against said upper and lower shoulders of said plurality of annular grooves.
Claim 6
Dependent Claim
32 words
A seal assembly as set forth in claim 4 wherein said corrugated spring is preferably made of copper berylium heat treated to maintain the spring capability at a wide range of temperatures.
Claim 7
Dependent Claim
21 words
A seal assembly as set forth in claim 4 wherein said resting rings are made of a solid heat metallic material.
Claim 8
Dependent Claim
17 words
A seal assembly as set forth in claim 6 wherein said solid hard metallic material is brass.
Claim 9
Dependent Claim
18 words
A seal assembly as set forth in claim 6 wherein said solid hard metallic material is grey iron.
Claim 10
Dependent Claim
40 words
A seal assembly as set forth in claim 4 wherein said resting rings are made of resilient material having a hard backplate wear resistant ring between said resilient material and said corrugated spring to prevent wear of said resilient material.
Claim 11
Dependent Claim
16 words
A seal assembly as set forth in claim 9 wherein said resilient material is Rulon J.
Claim 12
Dependent Claim
15 words
A seal assembly as set forth in claim 9 wherein said resilient material is fluorocarbon.
Claim 13
Dependent Claim
21 words
A seal assembly as set forth in either claim 10 or 11 wherein said hard backplate wear resistant ring is brass.
Claim 14
Dependent Claim
22 words
A seal assembly as set forth in either claim 10 or 11 wherein said hard backplate wear resistant ring is stainless steel.
Claim 15
Dependent Claim
18 words
A seal assembly as set forth in claim 5 wherein said sealing wedges are made of ceramic material.
Claim 16
Dependent Claim
21 words
A seal assembly as set forth in claim 14 wherein said ceramic material is sintered alumina (Al 2 O 3 ).
Claim 17
Dependent Claim
22 words
A seal assembly as set forth in claim 14 wherein said ceramic material is partially stabilized heat treated zirconia (ZrO 2 ).
Claim 18
Dependent Claim
23 words
A seal assembly as set forth in claim 14 wherein said ceramic material is hot pressed silicon nitride (Si 3 N 4 ).
Claim 19
Dependent Claim
21 words
A seal assembly as set forth in claim 14 wherein said ceramic material is hot pressed boron carbide (B 4 C).
Claim 20
Dependent Claim
135 words
A seal assembly as set forth in claim 15 wherein said dry seal means comprised of two resting rings having at least one beveled edge on the outer periphery and a free-floating sealing wedge form fitted into each of the beveled edges are one beveled edge and a free-floating sealing wedge on opposite sides of said two resting rings whereby each of the two sealing wedges alternately frictionally slide along said cylinder wall by having side pressure applied thereagainst by said beveled edge while moving in one direction and free-floats away from said beveled edge and said cylinder wall while moving in the opposite direction whereby equal pressures are maintained in the compression stroke and said sealing wedges adjust for wear while said resting rings and said sealing wedges change dimensions during wide temperature operation.
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) | 1986-10-24 | 1987-04-25 | 1987-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-24 | 1991-04-25 | 1991-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-24 | 1995-04-25 | 1995-10-25 | $7700.00 | Window Closed / Lapsed |