US3688644A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluid operated actuator for movable members
Assignee: Sperry Rand Australia Ltd
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Filing: 1970-09-18
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Granted: 1972-09-05
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Expires: 1990-09-18
Abstract
Abstract A fluid operated actuator for controlling the movement of a member such as a valve and being connectable into a fluid circuit including pressure operated means for indicating extreme operative positions of the aforementioned member. The actuator including a piston-cylinder assembly, the piston of which is connectable to the aforementioned member, and pressure relief means operative to prevent the pressure acting on the piston reaching a predetermined level which is below that necessary to operate the indicating means. Cut-out means is provided within the piston-cylinder assembly to render the relief means inoperative when the piston reaches or approaches positions corresponding to the aforementioned extreme operative positions of the associated member, so that the pressure acting on the piston is able to rise sufficiently to operate the indicating means.
Inventors
- 👤 John Cusveller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 02:49
CPC Classifications
F; F15; F15B; F15B15/00; F15B15/02; F15B15/06; F15B15/065; F15B15/08; F15B15/14; F15B15/1423; F15B15/1447; F15B15/149; F15B15/20; F15B15/28; F15B15/2815; F15B15/2838
Claims Analysis
Total Claims: 41
Claim 1
Independent Claim
141 words
A fluid operated actuator including an actuator element movable under the influence of fluid pressure and being connectable to a member to be actuated, pressure relief means operable to prevent the pressure acting on said actuator element reaching a predetermined level, and cut-out means operable to render said relief means inoperative when said actuator element adopts a particular axial position, said actuator element being defined by a piston assembly which is slidable axially within a cylinder and divides the interior of that cylinder trAnsversely into two chambers, and said pressure relief means communicates with at least one of said chambers when said cut-out means is inoperative, said cut-out means including valve means forming at least part of said piston assembly for closing communication between said one chamber and said relief means when said actuator element is in said particular axial position.
Claim 2
Dependent Claim
141 words
A fluid operated actuator including an actuator element movable under the influence of fluid pressure and being connectable to a member to be actuated, pressure relief means operable to prevent the pressure acting on said actuator element reaching a predetermined level, and cut-out means operable to render said relief means inoperative when said actuator element adopts a particular axial position, said actuator element being defined by a piston assembly which is slidable axially within a cylinder and divides the interior of that cylinder trAnsversely into two chambers, and said pressure relief means communicates with at least one of said chambers when said cut-out means is inoperative, said cut-out means including valve means forming at least part of said piston assembly for closing communication between said one chamber and said relief means when said actuator element is in said particular axial position.
Claim 3
Dependent Claim
67 words
An actuator according to claim 1, wherein said cylinder includes inlet means for both said chambers whereby pressurized fluid may be introduced to either of said chambers according to the desired direction of movement of the piston assembly; and said pressure relief means is operable to relieve pressure from whichever of said chambers is subjected to said pressurized fluid, so long as said cut-out means remains inoperative.
Claim 4
Dependent Claim
16 words
An actuator according to claim 1, wherein said relief means includes at least one relief valve.
Claim 5
Dependent Claim
27 words
An actuator according to claim 2, wherein said relief means includes two relief valves, each of which is operatively connected to a respective one of said chambers.
Claim 6
Dependent Claim
80 words
An actuator according to claim 1, wherein said piston assembly has a first said particular operative position in which said part thereof closes communication between one of said chambers and said pressure relief means, and is positioned adjacent the end of the cylinder remote from that chamber; and a second said particular axial position in which said part thereof closes communication between the other said chamber, and is positioned adjacent the end of said cylinder opposite said firstmentioned end thereof.
Claim 7
Dependent Claim
92 words
An actuator according to claim 1, wherein means is provided to reduce the effective end surface area of the piston assembly to which pressurized fluid is applied to cause movement of the piston assembly in one direction, said means being arranged to cause said area reduction when said piston assembly is at or adjacent the said particular axial position; and the opposite effective end surface area of the piston assembly in which pressurized fluid is applied for initially moving the piston assembly in the opposite direction, is greater than said reduced area.
Claim 8
Dependent Claim
93 words
An actuator according to claim 1, wherein said piston assembly has a first said particular operative position in which a first part of said piston assembly closes communication between one of said chambers and said pressure relief means, and is positioned adjacent the end of the cylinder remote from that chamber; and a second said particular operative position in which a second part of said piston assembly closes communication between the other said chamber and said pressure relief means, and is positioned adjacent the end of said cylinder opposite said firstmentioned end thereof.
Claim 9
Dependent Claim
137 words
A fluid operated actuator including, a cylinder, a piston assembly slidable axially within said cylinder and dividing the interior thereof transversely to define two variable volume chambers, inlet means to allow introduction of pressurized fluid to one of said chambers, connecting means projecting through a wall of said cylinder for connecting said piston assembly to a member to be actuated, pressure relief means connected to said one chamber and being operable to prevent the fluid pressure therein reaching a predetermined level, and cut-out means operable to render the relief means inoperative when the piston assembly adopts a particular axial position relative to said cylinder, said cut-out means including valve means forming part of said piston assembly for closing communication between said one chamber and said pressure relief means when said piston assembly adopts said particular axial position.
Claim 10
Dependent Claim
137 words
A fluid operated actuator including, a cylinder, a piston assembly slidable axially within said cylinder and dividing the interior thereof transversely to define two variable volume chambers, inlet means to allow introduction of pressurized fluid to one of said chambers, connecting means projecting through a wall of said cylinder for connecting said piston assembly to a member to be actuated, pressure relief means connected to said one chamber and being operable to prevent the fluid pressure therein reaching a predetermined level, and cut-out means operable to render the relief means inoperative when the piston assembly adopts a particular axial position relative to said cylinder, said cut-out means including valve means forming part of said piston assembly for closing communication between said one chamber and said pressure relief means when said piston assembly adopts said particular axial position.
Claim 11
Dependent Claim
67 words
An actuator according to claim 8, wherein fluid inlet and outlet means is provided for both said chambers so that pressurized fluid may be introduced to either of said chambers according to the desired direction of movement of the piston assembly, and said pressure relief means is connected to both said chambers to control the pressure within whichever of said cHambers is subjected to said pressurized fluid.
Claim 12
Dependent Claim
86 words
An actuator according to claim 9, wherein a single port defines both the inlet means and the outlet means for each said chamber, said ports communicating with their respective chambers through a pressure operated control valve arranged to open both said ports to their respective chambers in response to pressurized fluid being fed into either one of said ports, whereby the port receiving said pressurized fluid functions as inlet means for its respective chamber and the other said port functions as outlet means for its chamber.
Claim 13
Dependent Claim
45 words
An actuator according to claim 10, wherein said control valve has biasing means to normally close communication between both said ports and their respective chambers, and safety valve means is connected to both said chambers to prevent the pressure therein exceeding a predetermined upper limit.
Claim 14
Dependent Claim
24 words
An actuator according to claim 8, wherein said pressure relief means includes a relief valve operatively connected to at least one of said chambers.
Claim 15
Dependent Claim
28 words
An actuator according to claim 8, wherein said pressure relief means includes two relief valves, each of which is operatively connected to a respective one of said chambers.
Claim 16
Dependent Claim
17 words
An actuator according to claim 13, wherein each said relief valve is contained within said piston assembly.
Claim 17
Dependent Claim
124 words
An actuator according to claim 8, wherein said piston assembly includes a secondary piston which is connected to an end portion of a piston rod which forms at least part of said connecting means, and a primary piston which is slidably mounted on said secondary piston for limited axial movement relative thereto; said piston rod projecting through an end wall of said cylinder and being movable axially relative to the cylinder with said secondary piston; said pressure relief means includes a passage formed through said secondary piston to provide communication between said chambers; and said valve means includes at least part of said primary piston which is arranged to open or close said communication according to its axial position relative to said secondary piston.
Claim 18
Dependent Claim
50 words
An actuator according to claim 13, wherein said relief means passage has an entrance portion which extends laterally through the surface of said secondary piston over which said primary piston slides, said primary piston part being located over said entrance portion and closing same when in said particular axial position.
Claim 19
Dependent Claim
86 words
An actuator according to claim 16, wherein; said primary piston includes an inner sleeve section slidable on said secondary piston, and an outer sleeve section which is slidable on said inner sleeve section; stop means is provided on said secondary piston to limit axial movement of said inner sleeve section relative to the secondary piston; and said outer sleeve section is located between opposed annular shoulders of said inner sleeve section and is engageable therewith to limit its axial movement relative to said inner sleeve section.
Claim 20
Dependent Claim
65 words
An actuator according to claim 17, wherein an opening extends radially through said inner sleeve section and remains in communication with said passage entrance portion in all axial positions of said inner sleeve section relative to said secondary piston, and communication between said entrance portion and the adjacent cylinder chamber is closed by engagement between said outer sleeve section and one of said annular shoulders.
Claim 21
Dependent Claim
80 words
An actuator according to claim 17, wherein an abutment is provided within said cylinder for engagement by said outer sleeve section to limit axial movement of said outer sleeve section relative to the cylinder in one direction; and said inner sleeve section and secondary piston are able to move further in said one direction after said outer sleeve section and said abutment engage, whereby said outer sleeve section is located relative to said secondary piston to close said relief passage.
Claim 22
Dependent Claim
92 words
An actuator according to claim 19, wherein said relief passage is closed when said outer sleeve sectIon engages both the said abutment and the said annular shoulder located remote from said abutment; and in that position of the piston assembly the effective end area thereof which is engageable by pressurized fluid to move the said secondary piston further in said one direction, is smaller than the effective opposite end area of the piston assembly which is engageable by pressurized fluid to move said assembly in the direction opposite to said one direction.
Claim 23
Dependent Claim
19 words
An actuator according to claim 15, wherein said relief means includes a one-way valve located in said relief passage.
Claim 24
Dependent Claim
43 words
An actuator according to claim 15, wherein two said passages are formed through said secondary piston, and said primary piston part is movable axially relative to the secondary piston between two positions in each of which said part closes a respective said passage.
Claim 25
Dependent Claim
110 words
An actuator according to claim 17, wherein two said passages are formed through said secondary piston, said primary piston part is movable axially relative to the secondary piston between two positions in each of which said part closes a respective said passage, two openings extend radially through said inner sleeve section and each remains in communication with the entrance portion of a respective one of said passages in all axial positions of said inner sleeve section relative to said secondary piston, and communication between each said entrance portion and the adjacent cylinder chamber is closed by engagement between said outer sleeve section and a respective one of said annular shoulders.
Claim 26
Dependent Claim
123 words
An actuator according to claim 18, wherein two said passages are formed through said secondary piston; said primary piston part is movable axially relative to the secondary piston between two positions in each of which said part closes a respective said passage; a pair of spaced abutments are provided within said cylinder for engagement by said outer sleeve section to limit axial movement of said outer sleeve section relative to the cylinder in two opposite directions; and said inner sleeve section and secondary piston are able to move further in each said direction after said outer sleeve section and the respective said abutment engage, whereby said outer sleeve section is located relative to said secondary piston to close the respective said relief passage.
Claim 27
Dependent Claim
53 words
An actuator according to claim 24, wherein said outer sleeve section engages a respective said abutment in each of said two positions, and a reduction in the said effective end area of the piston assembly occurs in each of said positions, the said end area reduced being opposite for each of said positions.
Claim 28
Dependent Claim
34 words
An actuator according to claim 22, wherein said relief means includes a one-way relief valve located in each said passage, and said valves are arranged to allow passage of fluid in respective opposite directions.
Claim 29
Dependent Claim
83 words
An actuator according to claim 15, wherein a combined inlet and outlet port is provided for each said chamber, each said port communicating with its respective said chamber through a pressure-operated control valve arranged to open both said ports to their respective chambers in response to pressurized fluid being fed into either one of said ports, whereby the port receiving said pressurized fluid functions as inlet means for its respective chamber and the other said port functions as outlet means for its chamber.
Claim 30
Dependent Claim
45 words
An actuator according to claim 27, wherein said control valve has biasing means to normally close communication between both said ports and their respective chambers, and safety valve means is connected to both said chambers to prevent the pressure therein exceeding a predetermined upper limit.
Claim 31
Dependent Claim
71 words
An actuator according to claim 27, wherein said control valve is contained in a valve block secured to one end of said cylinder; said block including two valve compartments, one of which communicates directly with the adjacent said cylinder chamber, and the other communicates with the remote said cylinder chamber through a coNduit; and each said port is connected to a respective said valve compartment when said control valve is opened.
Claim 32
Dependent Claim
83 words
An actuator according to claim 29, wherein said control valve includes two one-way valve elements which are biased by spring means towards each other into closed positions in which each closes communication between a respective said port and valve compartment, and an axially slidable spool element disposed between said valve elements and providing a fluid seal between said ports; said spool being operative to open one said valve element in response to fluid pressure in the port of the other said valve element.
Claim 33
Dependent Claim
114 words
An actuator according to claim 8, wherein: said piston assembly includes two cylindrical end portions, an intermediate portion joining said end portions, and a rack formed on said intermediate portion and drivably engageable with a pinion projecting through an aperture in a side wall of said cylinder, said rack and pinion forming at least part of said connecting means; said relief means includes a main relief passage providing a communication between said chambers; and said valve means includes at least one of said end portions of the piston assembly which is arranged to open or close said communication between said chambers according to the axial position of the piston assembly relative to said cylinder.
Claim 34
Dependent Claim
51 words
An actuator according to claim 31, wherein said main relief passage is defined by a conduit located externally of said cylinder and which communicates with each said chamber through a respective passage extending axially of the cylinder and arranged to be closed by the adjacent end surface of the piston assembly.
Claim 35
Dependent Claim
63 words
An actuator according to claim 32, wherein each said axial passage is formed in a stop element which projects axially into said cylinder from a respective end wall thereof, the end surface of each stop element which is located within said cylinder serving as an abutment for the adjacent end of said piston assembly and having the respective said axial passage opening therethrough.
Claim 36
Dependent Claim
33 words
An actuator according to claim 33, wherein each said stop element is adjustably mounted in the respective cylinder end wall to enable variation of the axial position of the said end surface thereof.
Claim 37
Dependent Claim
43 words
An actuator according to claim 31, wherein said relief means include relief valve means connected to said main relief passage and operable to open and close communication between said chambers through said main passage, according to the fluid pressure existing in said chambers.
Claim 38
Dependent Claim
75 words
An actuator according to claim 35, wherein said relief valve means includes a valve housing having a compartment therein, said main passage communicating direct with said compartment and with one of said cylinder chambers, and compartment inlet and outlet passages each of which communicates with the other said cylinder chamber and is controlled by a respective one-way valve, the two said one-way valves being arranged to respectively allow fluid into and out of said compartment.
Claim 39
Dependent Claim
133 words
An actuator according to claim 32, wherein said relief means include relief valve means connected to said main relief passage and operable to open and close communication between said chambers through said main passage, according to the fluid pressure existing in said chambers; said relief valve means including a valve housing having a compartment therein, said main passage communicating direct with said compartment and with one of said cylinder chambers, and compartment inlet and outlet passages each of which communicates with the other said cylinder chamber and is controlled by a respective one-way valve, the two said one-way valves being arranged to respectively allow fluid into and out of said compartment, said compartment inlet passage communicating with one of said axial passages, and said conduit communicating direct with the other said axial passage.
Claim 40
Dependent Claim
32 words
An actuator according to claim 37, wherein said relief valve means includes a manually operable by-pass valve whIch is operable to open direct communication between said conduit and said one axial passage.
Claim 41
Dependent Claim
173 words
An actuator according to claim 31, wherein each of the opposite end walls of said cylinder is defined by a valve block which includes: a combined fluid supply and exhaust port, a pressure operable one-way valve which is normally biased into a closed position and controls fluid flow through said port, and an axially slidable spool element which is pressure operable to open said one-way valve; and respective drain passage means connects the said port of each said valve block to a rear side of the said spool element of the other said valve block, whereby pressurized fluid supplied to one said chamber through the adjacent said valve block is operative to cause the said spool element of the other said valve block to open its respective said one-way valve and thereby allow said other chamber to exhaust. 40 An actuator according to claim 39, wherein safety valve means is provided within each said valve block and communicates with the adjacent said chamber to prevent the pressure therein exceeding a predetermined upper limit.
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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) | 1975-09-05 | 1976-03-06 | 1976-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-05 | 1980-03-06 | 1980-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-05 | 1984-03-06 | 1984-09-05 | $7700.00 | Window Closed / Lapsed |