US3598506A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrostrictive actuator
Assignee: Physics International Co
•
Filing: 1969-04-23
•
Granted: 1971-08-10
•
Expires: 1989-04-23
Abstract
Abstract Apparatus is disclosed for doing useful work with electroexpansive material which expands volumetrically in response to an electric field. The material is disposed in a chamber of a fixed volume slightly greater than the volume of the material at rest. The volume intermediate the material and the chamber is filled with a fluid having good insulation properties. When the material expands in response to an electrical signal, insulating fluid is forced out of a passage in a wall of the chamber and performs work by actuating a plunger or diaphragm. Means, such as an intermediate piston, may be employed to isolate the insulating fluid from the hydraulic fluid in a device being thus hydraulically driven, such as a pump valving means or fluid control valve.
Inventors
- 👤 Cormac Garrett O'neill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:48
CPC Classifications
F; F04; F04B; F04B17/00; F04B17/003; B; B06; B06B; B06B1/00; B06B1/02; B06B1/06; B06B1/0607; B06B1/0611; F04B43/00; F04B43/08; F04B43/09; F04B43/095; F04B43/10; H; H02; H02N; H02N2/00; H02N2/02; H02N2/04; H02N2/043; H10; H10N; H10N30/00; H10N30/50
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
137 words
An electroexpansively powered fluid driver comprising: a body having a chamber of a given volume and a passage in a wall thereof communicating with said chamber; volumetric electroexpansive material disposed in said chamber, said material being a solid and having a total volume less than said given volume of said chamber; nonconductive fluid filling said chamber and in direct contact with said electroexpansive material on all sides free to move in response to an electric field applied to said electroexpansive material such that all of said fluid will be at the same pressure at any given time; and means for applying an electric signal as a potential across said material to create said electric field to cause said material to undergo a total volume change to perform work by forcing fluid from said chamber through said passage.
Claim 2
Dependent Claim
137 words
An electroexpansively powered fluid driver comprising: a body having a chamber of a given volume and a passage in a wall thereof communicating with said chamber; volumetric electroexpansive material disposed in said chamber, said material being a solid and having a total volume less than said given volume of said chamber; nonconductive fluid filling said chamber and in direct contact with said electroexpansive material on all sides free to move in response to an electric field applied to said electroexpansive material such that all of said fluid will be at the same pressure at any given time; and means for applying an electric signal as a potential across said material to create said electric field to cause said material to undergo a total volume change to perform work by forcing fluid from said chamber through said passage.
Claim 3
Dependent Claim
46 words
Apparatus as defined in claim 1 including pump valving means comprising: a pump chamber having a port connected to said passage; fluid inlet means having a one-way valve communicating with said pump chamber; and fluid outlet means having a one-way valve communicating with said pump chamber.
Claim 4
Dependent Claim
77 words
Apparatus as defined in claim 1 wherein said chamber is a cylinder and said material is in the form of a plurality of segmental sections, said sections being disposed about a central spring tube through which electrical contact is made with each section while each section is being urged against the cylindrical wall of said chamber, said wall being made of electrical conductive material, and said means is connected between said spring tube and said cylindrical wall.
Claim 5
Dependent Claim
46 words
Apparatus as defined in claim 3 including pump valving means comprising: a pump chamber having a port connected to said passage; fluid inlet means having a one-way valve communicating with said pump chamber; and fluid outlet means having a one-way valve communicating with said pump chamber.
Claim 6
Dependent Claim
141 words
An electroexpansively powered driver comprising: a hydraulic cylinder; a body having a hydraulic fluid chamber of a given volume and a passage in a wall thereof communicating with said hydraulic cylinder; volumetric electroexpansive material so disposed in said chamber as to provide a hydraulic drive chamber between said material and walls of said chamber; a piston disposed in said cylinder; fluid filling said hydraulic drive chamber and passage to said piston in said cylinder, said fluid surrounding said electroexpansive material on all sides free to move in response to an electrical field applied to said electroexpansive material such that all of said fluid will be aT the same pressure at any given time; and means for applying an electric field to said material to cause said material to undergo a total volume increase to hydraulically advance said piston in said cylinder.
Claim 7
Dependent Claim
141 words
An electroexpansively powered driver comprising: a hydraulic cylinder; a body having a hydraulic fluid chamber of a given volume and a passage in a wall thereof communicating with said hydraulic cylinder; volumetric electroexpansive material so disposed in said chamber as to provide a hydraulic drive chamber between said material and walls of said chamber; a piston disposed in said cylinder; fluid filling said hydraulic drive chamber and passage to said piston in said cylinder, said fluid surrounding said electroexpansive material on all sides free to move in response to an electrical field applied to said electroexpansive material such that all of said fluid will be aT the same pressure at any given time; and means for applying an electric field to said material to cause said material to undergo a total volume increase to hydraulically advance said piston in said cylinder.
Claim 8
Dependent Claim
56 words
Apparatus as defined in claim 5 including pump valving means comprising: a pump chamber having a port connected to said cylinder at the end thereof remote from said hydraulic drive chamber; fluid inlet means having a one-way valve communicating with said pump chamber; and fluid outlet means having a one-way valve communicating with said pump chamber.
Claim 9
Dependent Claim
21 words
Apparatus as defined in claim 6 including a return spring in said cylinder between said piston and said pump valving means.
Claim 10
Dependent Claim
62 words
Apparatus as defined in claim 5 wherein said piston has a portion at one end thereof with an area that differs from the area at the other end thereof, and said cylinder is of a diameter substantially equal to that of said portion over a sufficient length thereof to receive said portion of said piston and allow maximum travel of said piston.
Claim 11
Dependent Claim
20 words
Apparatus as defined in claim 8 including means for venting said cylinder at the base of the enlarged portion thereof.
Claim 12
Dependent Claim
149 words
An electroexpansively powered fluid driver comprising: a hydraulic cylinder; a body having an annular hydraulic fluid chamber of a given volume and a passage in a wall thereof communicating with said hydraulic cylinder; at least one tube of volumetric electroexpansive material so disposed in said chamber as to provide a hydraulic drive chamber between said tube and walls of said body; an actuating piston disposed in said cylinder; fluid filling said hydraulic drive chamber and passage to said piston in said cylinder, said fluid surrounding said electroexpansive material on all sides free to move in response to an electrical field applied to said electroexpansive material such that all of said fluid will be at the same pressure at any given time; and means for applying said electric field to said material to cause said material to undergo a total volume increase to hydraulically advance said piston in said cylinder.
Claim 13
Dependent Claim
149 words
An electroexpansively powered fluid driver comprising: a hydraulic cylinder; a body having an annular hydraulic fluid chamber of a given volume and a passage in a wall thereof communicating with said hydraulic cylinder; at least one tube of volumetric electroexpansive material so disposed in said chamber as to provide a hydraulic drive chamber between said tube and walls of said body; an actuating piston disposed in said cylinder; fluid filling said hydraulic drive chamber and passage to said piston in said cylinder, said fluid surrounding said electroexpansive material on all sides free to move in response to an electrical field applied to said electroexpansive material such that all of said fluid will be at the same pressure at any given time; and means for applying said electric field to said material to cause said material to undergo a total volume increase to hydraulically advance said piston in said cylinder.
Claim 14
Dependent Claim
18 words
Apparatus as defined in claim 10 including an arm extending from said cylinder for actuation of a device.
Claim 15
Dependent Claim
26 words
Apparatus as defined in claim 11 wherein said device is a valve and the end of said arm remote from said piston comprises a valving plunger.
Claim 16
Dependent Claim
26 words
Apparatus as defined in claim 11 wherein said device is a pump and the end of said arm remote from said piston comprises a pumping piston.
Claim 17
Dependent Claim
22 words
Apparatus as defined in claim 13 wherein said pumping piston has a diameter that differs from the diameter of said actuating piston.
Claim 18
Dependent Claim
40 words
Apparatus as defined in claim 10 wherein a second tube of volumetric electroexpansive material is disposed in said chamber and said means functions for said second tube in the same manner as for said one tube of volumetric electroexpansive material.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-08-09 | 1975-02-08 | 1975-08-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-09 | 1979-02-08 | 1979-08-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-09 | 1983-02-08 | 1983-08-10 | $7700.00 | Window Closed / Lapsed |