Patent US4261377A successfully refreshed from Google Patents.
US3889904A
Expired / Lapsed
US
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Means and method for servicing fluid cushioned aircraft landing gear struts
Assignee: Individual
•
Filing: 1973-06-20
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Granted: 1975-06-17
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Expires: 1993-06-20
Abstract
Abstract A method for servicing fluid cushioned aircraft landing gear struts wherein a portable vehicle is provided for use at airports or aircraft landing areas, for use in replacing used fluids in aircraft landing gear struts. The method comprising the release of fluids from collapsible aircraft landing gear struts by opening a fitting communicating with the interior thereof and allowing the weight of the aircraft to move the aircraft downward uniformly in a direction to cause collapse of the respective struts and to thereby force fluids to be purged therefrom as the weight of the aircraft moves the aircraft downward uniformly and causes the respective struts to collapse. The method also comprising introducing new fluids through the fitting for the purpose of pressurizing the interior of the respective strut and causing it to expand and lift the weight of the aircraft uniformly to a normal operating position whereby the entire servicing method of the invention allows the aircraft to rest upon a wheel supporting surface during the purging of old fluid from the struts and the charging of new fluid thereinto.
Inventors
- 👤 Chester L M Jones
- 👤 Raymond J Yoakam
- 👤 Mitchell M Hazar
- 👤 Alfred J Dillon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 01:33
CPC Classifications
B; B64; B64C; B64C25/00; B64C25/32; B64C25/58; B64C25/60; B64F; B64F5/00; B64F5/60; Y; Y02; Y02P; Y02P70/00; Y02P70/50
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
124 words
A method for servicing fluid cushioned collapsible aircraft landing gear struts comprising: allowing an aircraft to rest and bear on its landing gear with the supporting wheels thereof in contact with a floor surface such as hangar floor, runway, or any other support; then opening a fluid fitting in each respective landing gear strut while allowing the weight of the aircraft to move downward uniformly under the force of gravity thereby collapsing said struts and thereby forcing used fluid therefrom; then applying new fluid under pressure through said fitting and thereby uniformly extending said struts and uniformly elevating said aircraft while the weight of said aircraft is still supported on said struts and while the respective wheels are still engaged with said floor surface.
Claim 2
Independent Claim
124 words
A method for servicing fluid cushioned collapsible aircraft landing gear struts comprising: allowing an aircraft to rest and bear on its landing gear with the supporting wheels thereof in contact with a floor surface such as hangar floor, runway, or any other support; then opening a fluid fitting in each respective landing gear strut while allowing the weight of the aircraft to move downward uniformly under the force of gravity thereby collapsing said struts and thereby forcing used fluid therefrom; then applying new fluid under pressure through said fitting and thereby uniformly extending said struts and uniformly elevating said aircraft while the weight of said aircraft is still supported on said struts and while the respective wheels are still engaged with said floor surface.
Claim 3
Dependent Claim
49 words
The invention as defined in claim 1, wherein: said new fluid is hydraulic flushing fluid; then permitting said flushing fluid to escape from said struts while the weight of said aircraft causes it to move down and again collapses said struts and expels said flushing fluid from said struts.
Claim 4
Dependent Claim
74 words
The invention as defined in claim 2, wherein: some of said flushing fuid is retained in said struts for lubrication; and then forcing pneumatic fluid through said fitting until said struts are further extended to a position wherein each of said struts elevates said aircraft and supports its share of weight of said aircraft at thE proper elevation; then closing said fitting to retain said lubricating oil and said pneumatic fluid in said struts.
Claim 5
Dependent Claim
46 words
The invention as defined in claim 1, wherein: a conduit is coupled to said fitting and to a container for collecting fluid forced from said struts when said aircraft moves down by force of gravity to collapse said struts during the expelling of used fluid therefrom.
Claim 6
Dependent Claim
47 words
The invention as defined in claim 2, wherein: a conduit is coupled to said fitting and to a container to collect used fluid therefrom when said fluid is forced from from struts as force of gravity causes said aircraft to move downward and to collapse said struts.
Claim 7
Dependent Claim
182 words
A means for servicing fluid cushioned collapsible aircraft landing gear struts comprising a portable frame; fluid supply means adapted to contain fluid and carried on said frame; second means communicating with said fluid supply means; said second means adapted for pressurizing said fluid and adapted for delivering said fluid under pressure into a landing gear strut; said second means adapted to deliver said fluid under sufficient pressure to fill and extend said strut while elevating the weight of said aircraft by means of said strut; a container carried by said frame and communicting with said second means for receiving used fluid from said strut; and valve means communicating with said second means and said container alternately to exhaust fluid from said strut into said container and to deliver fluid into said strut via said second means, said second means is provided with a source of compressed pneumatic fluid and a source of hydraulic fluid; and accumulator means wherein said compressed pneumatic fluid imposes pressure on said hydraulic fluid whereby said accumulator is adapted to deliver hydraulic fluid under pressure to said strut.
Claim 8
Dependent Claim
182 words
A means for servicing fluid cushioned collapsible aircraft landing gear struts comprising a portable frame; fluid supply means adapted to contain fluid and carried on said frame; second means communicating with said fluid supply means; said second means adapted for pressurizing said fluid and adapted for delivering said fluid under pressure into a landing gear strut; said second means adapted to deliver said fluid under sufficient pressure to fill and extend said strut while elevating the weight of said aircraft by means of said strut; a container carried by said frame and communicting with said second means for receiving used fluid from said strut; and valve means communicating with said second means and said container alternately to exhaust fluid from said strut into said container and to deliver fluid into said strut via said second means, said second means is provided with a source of compressed pneumatic fluid and a source of hydraulic fluid; and accumulator means wherein said compressed pneumatic fluid imposes pressure on said hydraulic fluid whereby said accumulator is adapted to deliver hydraulic fluid under pressure to said strut.
Claim 9
Dependent Claim
46 words
The invention as defined in claim 6 wherein said second means is also provided with control valve means disposed alternately to deliver said hydraulic fluid from said accumulator into said strut and to deliver pneumatic fluid from said source of compressed pneumatic fluid into said strut.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-16 | 1978-12-16 | 1979-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-16 | 1982-12-16 | 1983-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-16 | 1986-12-16 | 1987-06-17 | $7700.00 | Window Closed / Lapsed |