US3895560A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cylinder motion sensing
Assignee: Leesona Corp
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Filing: 1973-11-12
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Granted: 1975-07-22
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Expires: 1993-11-12
Abstract
Abstract Fluid back-pressure flowing out a cylinder when being powered through a stroke is sensed by fluid logic circuits to produce a signal which indicates that piston movement is slowed or stopped. A fluid logic device with a flexible impervious diaphragm senses the back pressure to provide an output signal when the piston is not functioning properly. The detector is made more sensitive and selective by restricting a flow path for the back-pressure and operating the logic device as a pressure amplifier, responsive to a threshold back-pressure valve. The sensor is operable to produce a negative going dynamic output transition as a signal that the piston rate is not exceeding a particular threshold value.
Inventors
- 👤 Ernest David Anderson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 03:51
CPC Classifications
F; F15; F15C; F15C3/00; F15C3/04; F01; F01B; F01B31/00; F01B31/12; F15C4/00
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
194 words
Apparatus for sensing the motion of a fluid operated piston within a cylinder, comprising in combination, a source of fluid under pressure, means gating said fluid to produce movement of said piston within said cylinder, a flow channel conveying exhaust fluid forced from the cylinder by movement of said piston, a fluid logic switching element having two fluid reception chambers and being responsive to pressure differential between two fluid pressures at said two chambers to switch a member from one condition to another, flow channel means coupling one said chamber to said source, means coupling the other said chamber to said flow channel conveying exhaust fluid, and means including said member in said switching element responsive to the differential pressure between said exhaust fluid and said source of fluid to switch said member, and output fluid flow path means coupled to said source and responsive to switching of said member to produce thereby at an output lead a fluid output signal in response to exhaust fluid exceeding a predetermined pressure magnitude indicating that the piston is moving at a predetermined rate within said cylinder thereby causing said exhaust fluid to exceed said pressure magnitude.
Claim 2
Dependent Claim
194 words
Apparatus for sensing the motion of a fluid operated piston within a cylinder, comprising in combination, a source of fluid under pressure, means gating said fluid to produce movement of said piston within said cylinder, a flow channel conveying exhaust fluid forced from the cylinder by movement of said piston, a fluid logic switching element having two fluid reception chambers and being responsive to pressure differential between two fluid pressures at said two chambers to switch a member from one condition to another, flow channel means coupling one said chamber to said source, means coupling the other said chamber to said flow channel conveying exhaust fluid, and means including said member in said switching element responsive to the differential pressure between said exhaust fluid and said source of fluid to switch said member, and output fluid flow path means coupled to said source and responsive to switching of said member to produce thereby at an output lead a fluid output signal in response to exhaust fluid exceeding a predetermined pressure magnitude indicating that the piston is moving at a predetermined rate within said cylinder thereby causing said exhaust fluid to exceed said pressure magnitude.
Claim 3
Dependent Claim
66 words
Apparatus as defined in claim 1 wherein said fluid logic element is a device with said member comprising a flexible impervious elastomeric diaphragm coupled for flexing in response to said exhaust fluid pressure and said means to produce a fluid signal includes a valve operated by said diaphragm to control fluid flow at a source pressure substantially greater than the pressure oF fluid from said exhaust.
Claim 4
Dependent Claim
33 words
Apparatus as defined in claim 1 wherein said logic element has said member comprising structure with two diaphragms separated by a movable control member with different areas in contact with the respective diaphragms.
Claim 5
Dependent Claim
36 words
Apparatus as defined in claim 1 including means restricting said flow channel conveying exhaust fluid at a position to increase to the pressure in said other chamber with the piston is moving to exhaust the fluid.
Claim 6
Dependent Claim
53 words
Apparatus as defined in claim 2 wherein said fluid logic element has a fluid flow path from said source with a valve therein controlled by said diaphragm member to provide said fluid output signal at said pressure of the source of fluid during the period the exhaust fluid exceeds a predetermined threshold pressure.
Claim 7
Dependent Claim
61 words
Apparatus as defined in claim 2 including restrictor delay means coupled in said flow channel means between said source and said one said chamber for delaying the initial flow of source pressure to reach said diaphragm thereby effectively applying said exhaust fluid pressure to said diaphragm before applying said fluid flow of said source at said greater pressure to said valve.
Claim 8
Dependent Claim
50 words
Apparatus as defined in claim 3 wherein said logic element has a valve seat controlled by said control member receiving a high pressure fluid and the different areas of the control member are selected to permit a low pressure exhaust pressure to switch said element by closing said valve seat.
Claim 9
Dependent Claim
41 words
Apparatus as defined in claim 7 wherein the pressures on the different end areas of said control member are established to cause said high pressure fluid to keep said valve seat open after said exhaust fluid falls below a predetermined pressure.
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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) | 1978-07-21 | 1979-01-20 | 1979-07-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-21 | 1983-01-20 | 1983-07-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-21 | 1987-01-20 | 1987-07-22 | $7700.00 | Window Closed / Lapsed |