US3828558A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Means and method for prevention of piston creep in free-piston reciprocating device
Assignee: Research Corp
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Filing: 1973-04-12
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Granted: 1974-08-13
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Expires: 1993-04-12
Abstract
Abstract A free-piston motion device is provided having means associated with either the cylindrical surface of the free-piston or with its co-acting cylinder or both to maintain the mid-point of the stroke of the piston in a predetermined relation to its cylinder during reciprocation of the piston.
Inventors
- 👤 W Beale
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 19:53
CPC Classifications
F; F02; F02G; F02G1/00; F02G1/04; F02G1/043; F02G1/0435
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
124 words
In a free-piston Stirling cycle engine or pump having at least one free-piston mounted for reciprocation in a cylinder, a pressurized gaseous fluid maintained in the cylinder at at least one end of the free-piston the improvement comprising means associated with the cylindrical walls of the piston and the cylinder for reducing the tendency of the piston to creep into or out of the working gas space of the cylinder as it reciprocates in the cylinder, wherein the cylinder has a snug piston receiving bore and means on the cylinder or piston or both providing at least one gas Passage of a length less than the length of the piston and extending in opposite directions from the mid-point of the stroke of the piston.
Claim 2
Dependent Claim
124 words
In a free-piston Stirling cycle engine or pump having at least one free-piston mounted for reciprocation in a cylinder, a pressurized gaseous fluid maintained in the cylinder at at least one end of the free-piston the improvement comprising means associated with the cylindrical walls of the piston and the cylinder for reducing the tendency of the piston to creep into or out of the working gas space of the cylinder as it reciprocates in the cylinder, wherein the cylinder has a snug piston receiving bore and means on the cylinder or piston or both providing at least one gas Passage of a length less than the length of the piston and extending in opposite directions from the mid-point of the stroke of the piston.
Claim 3
Dependent Claim
18 words
The free-piston Stirling cycle device defined in claim 1 wherein the gas passage is provided on the piston.
Claim 4
Dependent Claim
23 words
The free piston Stirling cycle device defined in claim 1 wherein the gas passage is provided in the cylindrical wall of the cylinder.
Claim 5
Dependent Claim
125 words
In a free-piston motion device having at least one free-piston mounted for reciprocation in a cylinder, a pressurized gaseous fluid maintained in the cylinder at at least one end of the free-piston the improvement comprising means associated with the cylindrical walls of the piston and the cylinder for reducing the tendency of the piston to creep into or out of the working gas space of the cylinder as it reciprocates in the cylinder, wherein the cylinder has a snug piston receiving bore of a length less than the length of the piston and said piston is provided with at least one gas passage in the cylindrical wall thereof of a length less than the length of the piston and positioned intermediate of the piston length.
Claim 6
Dependent Claim
125 words
In a free-piston motion device having at least one free-piston mounted for reciprocation in a cylinder, a pressurized gaseous fluid maintained in the cylinder at at least one end of the free-piston the improvement comprising means associated with the cylindrical walls of the piston and the cylinder for reducing the tendency of the piston to creep into or out of the working gas space of the cylinder as it reciprocates in the cylinder, wherein the cylinder has a snug piston receiving bore of a length less than the length of the piston and said piston is provided with at least one gas passage in the cylindrical wall thereof of a length less than the length of the piston and positioned intermediate of the piston length.
Claim 7
Independent Claim
71 words
A method of reducing the tendency of a free-piston of a free-piston motion device to creep into or out of the working space of its cooperating cylinder comprising the steps: forming a bore in a cylinder to snugly receive a piston within the bore; and forming an axial gas passage in the cylindrical surface of the piston, the cylinder, or both of a length less than the length of the piston.
Claim 8
Independent Claim
71 words
A method of reducing the tendency of a free-piston of a free-piston motion device to creep into or out of the working space of its cooperating cylinder comprising the steps: forming a bore in a cylinder to snugly receive a piston within the bore; and forming an axial gas passage in the cylindrical surface of the piston, the cylinder, or both of a length less than the length of the piston.
Claim 9
Dependent Claim
15 words
The method defined in claim 5 wherein the gas passage is formed in the cylinder.
Claim 10
Dependent Claim
15 words
The method defined in claim 5 wherein the gas passage is formed in the piston.
Claim 11
Dependent Claim
150 words
In a free-piston Stirling cycle engine or pump having at least one free power piston mounted for reciprocation in a cylinder, a pressurized gaseous fluid maintained in the cylinder at at least one end of the power piston the improvement comprising means associated with the cylindrical walls of the piston and the cylinder for reducing the tendency of the piston to creep into or out of the working space of the cylinder as it reciprocates in the cylinder, wherein the cylinder has a snug piston receiving bore of a length less than the length of the piston and said piston is provided with at least one gas passage in the cylindrical wall thereof of a length slightly greater than the piston receiving bore of the cylinder and wherein the said gas passage is of a length less than the length of the piston and positioned intermediate of the piston length.
Claim 12
Dependent Claim
150 words
In a free-piston Stirling cycle engine or pump having at least one free power piston mounted for reciprocation in a cylinder, a pressurized gaseous fluid maintained in the cylinder at at least one end of the power piston the improvement comprising means associated with the cylindrical walls of the piston and the cylinder for reducing the tendency of the piston to creep into or out of the working space of the cylinder as it reciprocates in the cylinder, wherein the cylinder has a snug piston receiving bore of a length less than the length of the piston and said piston is provided with at least one gas passage in the cylindrical wall thereof of a length slightly greater than the piston receiving bore of the cylinder and wherein the said gas passage is of a length less than the length of the piston and positioned intermediate of the piston length.
Claim 13
Independent Claim
93 words
A method of reducing the tendency of a free-piston of a free-piston Stirling cycle engine or pump to creep into or out of the working space of its cooperating cylinder comprising the steps: forming a bore in a cylinder to snugly receive a working piston with the bore having a length less than the length of the piston; and forming an axial gas passage in the cylindrical surface of the cooperating piston of a length slightly longer than the formed cylinder bore with the gas passage positioned intermediate the length of the piston.
Claim 14
Independent Claim
93 words
A method of reducing the tendency of a free-piston of a free-piston Stirling cycle engine or pump to creep into or out of the working space of its cooperating cylinder comprising the steps: forming a bore in a cylinder to snugly receive a working piston with the bore having a length less than the length of the piston; and forming an axial gas passage in the cylindrical surface of the cooperating piston of a length slightly longer than the formed cylinder bore with the gas passage positioned intermediate the length of the piston.
References Cited (Backward Citations)
US2833602A
Cited
US3319534A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-08-12 | 1978-02-11 | 1978-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-12 | 1982-02-11 | 1982-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-12 | 1986-02-11 | 1986-08-13 | $7700.00 | Window Closed / Lapsed |