Patent US4569562A successfully refreshed from Google Patents.
US4569562A
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US
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Method of and apparatus for controlling a fluid bearing
Assignee: Canon Inc
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Filing: 1983-10-19
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Granted: 1986-02-11
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Expires: 2003-10-19
Abstract
Abstract In a method of and an apparatus for controlling a fluid bearing, a state in which the power source of a control system is switched off (an open state) or a state in which a predetermined pressure different from the OFF condition is provided (a stopped state) is established when an abnormal condition in which the pressure reaches a predetermined value exceeding a servo-controlled upper or lower limit occurs, whereby the pressure of the fluid bearing is held within a safe pressure range.
Inventors
- 👤 Mitsuya Sato
- 👤 Isamu Shimoda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 06:19
CPC Classifications
F; F16; F16C; F16C29/00; F16C29/02; F16C29/025; F16C32/00; F16C32/06; F16C32/0603; F16C32/0614
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
86 words
A method of controlling a fluid bearing, comprising the steps of: determining upper and lower limits of pressure and servo-controlling the pressure of the fluid bearing within a predetermined range which includes the range between said upper and lower limits; and shifting the pressure toward and holding the pressure within a safe pressure range substantially identical to said range between said upper and lower limits, responsive to an occurrence of, an abnormal condition in which the pressure reaches a predetermined value outside of said predetermined range.
Claim 2
Independent Claim
86 words
A method of controlling a fluid bearing, comprising the steps of: determining upper and lower limits of pressure and servo-controlling the pressure of the fluid bearing within a predetermined range which includes the range between said upper and lower limits; and shifting the pressure toward and holding the pressure within a safe pressure range substantially identical to said range between said upper and lower limits, responsive to an occurrence of, an abnormal condition in which the pressure reaches a predetermined value outside of said predetermined range.
Claim 3
Dependent Claim
34 words
A method according to claim 1, wherein, responsive to occurrence of said abnormal condition, a control system is switched off to shift the pressure toward and hold the pressure within said safe pressure range.
Claim 4
Dependent Claim
36 words
A method according to claim 1, wherein, responsive to occurrence of said abnormal condition, a control system is switched off and the pressure at the time of said switching-off is shifted toward said safe pressure range.
Claim 5
Independent Claim
99 words
An apparatus for controlling a fluid bearing, comprising: means for determining upper and lower limits of pressure and servo-controlling the pressure of the fluid bearing within a predetermined range including the range between the upper and the lower limits; a pressure switch, said switch being operated responsive to an occurrence of an abnormal condition in which the pressure reaches a predetermined value outside of the predetermined range; and means for holding the pressure within a safe pressure range substantially identical to the range between the upper and the lower limits, in response to the operation of said pressure switch.
Claim 6
Independent Claim
99 words
An apparatus for controlling a fluid bearing, comprising: means for determining upper and lower limits of pressure and servo-controlling the pressure of the fluid bearing within a predetermined range including the range between the upper and the lower limits; a pressure switch, said switch being operated responsive to an occurrence of an abnormal condition in which the pressure reaches a predetermined value outside of the predetermined range; and means for holding the pressure within a safe pressure range substantially identical to the range between the upper and the lower limits, in response to the operation of said pressure switch.
Claim 7
Independent Claim
104 words
An apparatus for controlling a fluid bearing, comprising: means for determining upper and lower limits of pressure and servo-controlling the pressure of the fluid bearing within a predetermined range including the range between the upper and the lower limits; a nearing switch, said switch being operated responsive to an occurrence of an abnormal condition in which a movable portion of the fluid bearing and an immovable portion of the fluid bearing near each other within a predetermined zone; and means for holding the pressure within a safe pressure range substantially identical to the predetermined range in response to the operation of said nearing switch.
Claim 8
Independent Claim
104 words
An apparatus for controlling a fluid bearing, comprising: means for determining upper and lower limits of pressure and servo-controlling the pressure of the fluid bearing within a predetermined range including the range between the upper and the lower limits; a nearing switch, said switch being operated responsive to an occurrence of an abnormal condition in which a movable portion of the fluid bearing and an immovable portion of the fluid bearing near each other within a predetermined zone; and means for holding the pressure within a safe pressure range substantially identical to the predetermined range in response to the operation of said nearing switch.
Claim 9
Independent Claim
137 words
An apparatus for controlling a fluid bearing, comprising: means for determining upper and lower limits of pressure and servo-controlling the pressure of the fluid bearing within a predetermined range including the range between the upper and the lower limits; a pressure switch, said pressure switch being operated responsive to an occurrence of an abnormal condition in which the pressure reaches a predetermined value outside of the predetermined range; a nearing switch, said nearing switch being operated responsive to an occurrence of an abnormal condition in which a movable portion of the fluid bearing and an immovable portion of the third bearing near each other within a predetermined zone; and means for holding the pressure within a safe pressure range substantially identical to said predetermined range, in response to the operation of at least one of said switches.
Claim 10
Independent Claim
137 words
An apparatus for controlling a fluid bearing, comprising: means for determining upper and lower limits of pressure and servo-controlling the pressure of the fluid bearing within a predetermined range including the range between the upper and the lower limits; a pressure switch, said pressure switch being operated responsive to an occurrence of an abnormal condition in which the pressure reaches a predetermined value outside of the predetermined range; a nearing switch, said nearing switch being operated responsive to an occurrence of an abnormal condition in which a movable portion of the fluid bearing and an immovable portion of the third bearing near each other within a predetermined zone; and means for holding the pressure within a safe pressure range substantially identical to said predetermined range, in response to the operation of at least one of said switches.
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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) | 1989-02-10 | 1989-08-12 | 1990-02-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-02-10 | 1993-08-12 | 1994-02-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-02-10 | 1997-08-12 | 1998-02-11 | $7700.00 | Window Closed / Lapsed |