Patent US4748298A successfully refreshed from Google Patents.
Patent US4939512A successfully refreshed from Google Patents.
Patent US5235225A successfully refreshed from Google Patents.
US5235225A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Linear electrostatic actuator with means for concatenation
Assignee: Northwestern University
•
Filing: 1990-08-31
•
Granted: 1993-08-10
•
Expires: 2010-08-31
Abstract
Abstract Miniaturized linear electrostatic motor comprising a plurality of parallel stators and a flexible rotor disposed between adjacent stators. The stators may be fabricated by depositing a plurality of conductive electrodes on each facing surface of the stator or the electrodes may alternatively be placed on the flexible rotor element. The electrodes are selectively energized by a commutating circuit in a manner to effect movement of the rotor relative to the stator in a perpendicular to parallel motion. The electrostatic motor is particularly suitable for fabrication using photo-lithographic techniques and the formation of multi-layered, concatenated motor structures.
Inventors
- 👤 James E. Colgate
- 👤 Mark E. Axland
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 18:57
CPC Classifications
B; B82; B82Y; B82Y15/00; H; H02; H02K; H02K99/00; H02K41/00; H02N; H02N1/00; H02N1/002; H02N1/004
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
106 words
An electric linear actuator comprising: a plurality of substantially parallel stators; a flexible rotor disposed between at least two of the plurality of a substantially parallel stators; and a signal generator to generate a sequence of drive signals to generate electromagnetic fields between the stators and the rotor to effect a progressive transfer of the flexible rotor between the stators such that the rotor is transferred in a progressive manner in a direction substantially perpendicular to the stators from one stator to another stator to produce a motion of the rotor in a direction substantially parallel to the stator to provide a perpendicular to parallel motion.
Claim 2
Dependent Claim
106 words
An electric linear actuator comprising: a plurality of substantially parallel stators; a flexible rotor disposed between at least two of the plurality of a substantially parallel stators; and a signal generator to generate a sequence of drive signals to generate electromagnetic fields between the stators and the rotor to effect a progressive transfer of the flexible rotor between the stators such that the rotor is transferred in a progressive manner in a direction substantially perpendicular to the stators from one stator to another stator to produce a motion of the rotor in a direction substantially parallel to the stator to provide a perpendicular to parallel motion.
Claim 3
Dependent Claim
41 words
The electric linear actuator of claim 1 wherein each stator has a set of electrodes disposed on a surface facing another one of the substantially parallel plurality of stators and wherein the sequence of drive signals is coupled to the electrodes.
Claim 4
Dependent Claim
24 words
The electric linear actuator of claim 2 wherein the flexible rotor comprises a plastic film covered on two sides with a thin conductive layer.
Claim 5
Dependent Claim
25 words
The electric linear actuator of claim 2 wherein the flexible rotor comprises a thin flexible sheet having a plurality of perforations forming a screen-like structure.
Claim 6
Dependent Claim
32 words
The electric linear actuator of claim 1 wherein the stators are configured in a series structure and a plurality of rotors are disposed between the stators to form a series concatenated structure.
Claim 7
Dependent Claim
42 words
The electric linear actuator of claim 1 wherein the plurality of substantially parallel stators are arranged in a series-parallel configuration and a plurality of rotors are arranged in a series-parallel configuration and disposed between the stators to form a series-parallel concatenated structure.
Claim 8
Dependent Claim
42 words
The electric linear actuator of claim 2 wherein the rotor comprises a flexible conductive element which is maintained at a constant electrical potential and the signal generator comprises a switching circuit which generates drive signals as a sequence of rectangular voltage waveforms.
Claim 9
Dependent Claim
27 words
The electric linear actuator of claim 2 wherein the rotor comprises a central portion coupled to a load extension and to at least one flexible side extension.
Claim 10
Dependent Claim
16 words
The electric linear actuator of claim 2 wherein the electrodes are covered with an insulating layer.
Claim 11
Dependent Claim
22 words
The electric linear actuator of claim 2 wherein the rotor comprises a thin flexible conductive sheet covered with a layer of insulator.
Claim 12
Dependent Claim
29 words
The electric linear actuator of claim 1 wherein the rotor has a set of electrodes disposed thereon and wherein the sequence of drive signals is coupled to the electrodes.
Claim 13
Dependent Claim
30 words
The electric linear actuator of claim 11 wherein each of the stator comprises a conductive element maintained at a constant electrical potential and is covered with a thin insulating layer.
Claim 14
Dependent Claim
23 words
The electric linear actuator of claim 11 wherein the rotor comprises a thin flexible sheet having a plurality of perforations through the sheet.
Claim 15
Dependent Claim
16 words
The electric linear actuator of claim 11 wherein the electrodes are covered with an insulating layer.
Claim 16
Dependent Claim
32 words
The electric linear actuator of claim 11 wherein the stators are configured in a series structure and a plurality of rotors are disposed between the stators to form a series concatenated structure.
Claim 17
Dependent Claim
42 words
The electric linear actuator of claim 11 wherein the plurality of substantially parallel stators are arranged in a series-parallel configuration and a plurality of rotors are arranged in the series-parallel configuration and disposed between the stators to form a series-parallel concatenated structure.
Claim 18
Dependent Claim
35 words
The electric linear actuator of claim 1 further comprising sense means for sensing rotor position and wherein the signal generator comprises commutation means for generating the sequence of drive signals responsive to the sense means.
Claim 19
Dependent Claim
20 words
The electric linear actuator of claim 17 wherein the sense means comprises a set of contacts located on the rotor.
Claim 20
Dependent Claim
77 words
An electric actuator comprising: a plurality of substantial parallel stators spaced apart from each other; a flexible rotor disposed between at least two of the stators; and means for activating progressive transfer of the rotor between the stators such that the rotor is transferred in a progressive manner in a direction substantially perpendicular to the stator from one stator to another stator to produce a motion of the rotor in a direction substantially parallel to the stators.
Claim 21
Dependent Claim
77 words
An electric actuator comprising: a plurality of substantial parallel stators spaced apart from each other; a flexible rotor disposed between at least two of the stators; and means for activating progressive transfer of the rotor between the stators such that the rotor is transferred in a progressive manner in a direction substantially perpendicular to the stator from one stator to another stator to produce a motion of the rotor in a direction substantially parallel to the stators.
References Cited (Backward Citations)
DE972380C
Cited
US2975307A
Cited
US2893041A
Cited
US3838299A
Cited
US3805511A
Cited
US4205362A
Cited
SU744877A1
Cited
SU694962A1
Cited
US4736127A
Cited
US4642504A
Cited
US4520375A
Cited
US4689529A
Cited
US4814657A
Cited
US4922143A
Cited
US4754185A
Cited
JPS63136978A
Cited
US4760302A
Cited
US4767973A
Cited
US4789803A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-08-09 | 1997-02-08 | 1997-08-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-08-09 | 2001-02-08 | 2001-08-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-08-09 | 2005-02-08 | 2005-08-10 | $7700.00 | Window Closed / Lapsed |