US3767992A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Servo apparatus
Assignee: Lewis Engineering Co
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Filing: 1971-08-23
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Granted: 1973-10-23
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Expires: 1991-08-23
Abstract
Abstract A servo device which has but a single movable part that is essentially frictionless and which thus eliminates the usual gears and instead utilizes a galvanometer-type movement in a servo feedback loop arrangement. The galvanometer is associated with a bridge circuit and a novel light-cell control which is actuated by the galvanometer. The novel control comprises a movable element adapted to modify a light beam which is produced for the purpose of striking the light cell disposed in one bridge leg, and which originates at an electric lamp. Another leg of the bridge includes a condition-responsive element responding to heat, cold or other conditions in a manner to unbalance the bridge, the balance of which is then re-established by deflection of the galvanometer to activate the light control so as to modify the influence of the light cell (in the one bridge leg). The position of the movable element or coil of the galvanometer can be an indication of the magnitude of the cold, heat or other condition which is being monitored. The device can function as a position transducer for angular or linear values, as a basic function generator, including an electrical as well as mechanical output. By virtue of the single moving part there is had a desirable simplicity and reduced cost, with lower maintenance expense while at the same time accuracy is not sacrificed.
Inventors
- 👤 H Edwards
- 👤 S Bottorf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 07:43
CPC Classifications
G; G05; G05B; G05B1/00; G05B1/01; G05B1/04; G05B1/06; G01; G01D; G01D5/00; G01D5/12; G01D5/14; G01D5/20; G01D5/22; G01D5/26; G01D5/32; G01D5/34; G01R; G01R17/00; G01R17/02
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
275 words
A galvanometer-type servo device comprising in combination: a. a bridge having four legs which constitute interrelated circuits, b. condition-responsive means connected with one leg of said bridge for effecting an unbalance of the latter in response to changes in a condition, c. said bridge having terminals comprising output means connected to said legs, d. amplifying means having input and output circuitry, said input circuitry being connected to said output means to receive energy therefrom, e. a galvanometer connected to the output circuitry of the amplifying means to be operated thereby, f. a movable light-control member coupled to the galvanometer to be actuated thereby, g. a source of light having substantially constant amplitude, h. a light-sensitive conversion device connected to one of the legs of said bridge and adapted to receive light from said source, i. said movable light-control member being disposed in the path of light from the source to said conversion device and having light-controlling means cooperable with said light source and conversion device, for progressively diminishing or increasing the amount of light which passes from the source to the conversion device in response to movement of the member whereby any change in said condition which causes an unbalance of the bridge results in a deflection of the galvanometer to alter the light striking said conversion device in a manner that causes reestablishment of the bridge balance, and j. indicating means coupled to said galvanometer to be actuated thereby, said indicating means, comprising a scale having indicia adapted to designate values, and an index member, said scale and said index member being movable with respect to one another for designating values on said scale.
Claim 2
Dependent Claim
275 words
A galvanometer-type servo device comprising in combination: a. a bridge having four legs which constitute interrelated circuits, b. condition-responsive means connected with one leg of said bridge for effecting an unbalance of the latter in response to changes in a condition, c. said bridge having terminals comprising output means connected to said legs, d. amplifying means having input and output circuitry, said input circuitry being connected to said output means to receive energy therefrom, e. a galvanometer connected to the output circuitry of the amplifying means to be operated thereby, f. a movable light-control member coupled to the galvanometer to be actuated thereby, g. a source of light having substantially constant amplitude, h. a light-sensitive conversion device connected to one of the legs of said bridge and adapted to receive light from said source, i. said movable light-control member being disposed in the path of light from the source to said conversion device and having light-controlling means cooperable with said light source and conversion device, for progressively diminishing or increasing the amount of light which passes from the source to the conversion device in response to movement of the member whereby any change in said condition which causes an unbalance of the bridge results in a deflection of the galvanometer to alter the light striking said conversion device in a manner that causes reestablishment of the bridge balance, and j. indicating means coupled to said galvanometer to be actuated thereby, said indicating means, comprising a scale having indicia adapted to designate values, and an index member, said scale and said index member being movable with respect to one another for designating values on said scale.
Claim 3
Dependent Claim
34 words
The invention as set forth in claim 1, wherein: a. said light-controlling means comprises a turnably mounted reflector having a tapered reflecting surface, said reflector being adjustable through an arc of less than 360*.
Claim 4
Dependent Claim
42 words
The invention as set forth in claim 2, wherein: a. said movable control member is rotatably mounted and comprises a segment of a cylinder, and b. said tapered reflector has a curvature with a center at the axis of the control member.
Claim 5
Dependent Claim
34 words
The invention as set forth in claim 1, wherein: a. the movable control member is rotatably mounted and comprises a segment of a cylinder, b. said light-controlling means comprising edge portions of the member.
Claim 6
Dependent Claim
20 words
The invention as set forth in claim 4, wherein: a. said edge portions of the member comprise an aperture therethrough.
Claim 7
Dependent Claim
28 words
The invention as set forth in claim 1, wherein: a. said movable control member is carried directly by the moving system of the galvanometer and has arcuate movement.
Claim 8
Dependent Claim
49 words
The invention as set forth in claim 1, wherein: a. said control member comprises a sheet-like formation having opposite sides, and b. said light-controlling means constitutes a tapered configuration of said control member, enabling more or less light to pass from one side of the member to the other.
Claim 9
Dependent Claim
23 words
The invention as set forth in claim 7, wherein: a. said tapered configuration comprises edge porTions of an aperture in the control member.
Claim 10
Dependent Claim
33 words
The invention as set forth in claim 1, wherein: a. the control member comprises a sheet-like formation having opposite sides, and b. said light-controlling means comprises a tapered reflector carried by said member.
Claim 11
Dependent Claim
23 words
The invention as set forth in claim 1, wherein: a. said light-controlling means comprises edge portions of a tapered aperture in the member.
Claim 12
Dependent Claim
39 words
The invention as defined in claim 1, wherein: a. the light-controlling means constitutes edge portions of an aperture in the member, and b. a translucent film disposed across the aperture to reduce the intensity of the light passing therethrough.
Claim 13
Dependent Claim
28 words
The invention as defined in claim 1, wherein: a. said amplifying means comprises a pair of amplifiers providing output circuitry respectively of opposite polarity to operate the galvanometer.
Claim 14
Dependent Claim
45 words
The invention as defined in claim 12, wherein: a. the input circuitry of the first amplifier is connected across the condition-responsive means, and b. the input circuitry of the second amplifier is connected to legs of the bridge which do not include the condition-responsive means.
Claim 15
Dependent Claim
27 words
The invention as defined in claim 1, wherein: a. said light-controlling means is non-monotonous, thereby to enable various predetermined operation characteristics of the servo-device to be had.
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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) | 1976-10-22 | 1977-04-23 | 1977-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-22 | 1981-04-23 | 1981-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-22 | 1985-04-23 | 1985-10-23 | $7700.00 | Window Closed / Lapsed |