US3756356A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Brake for manually operated rotary file
Assignee: AVR Inc A CORP OF VA
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Filing: 1971-12-14
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Granted: 1973-09-04
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Expires: 1991-12-14
Abstract
Abstract A circular file is rotatably mounted on a base that includes an annular electromagnet secured against rotation but movable toward and away from the base of the file. The magnet may be electrically energized via one or more switches positioned at various locations around the file in order to cause the electromagnet to frictionally engage and stop rotation of the file at any desired position.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:25
CPC Classifications
G; G06; G06K; G06K17/00; G06K17/0003; G06K17/0009; F; F16; F16D; F16D55/00; F16D2121/00; F16D2121/18; F16D2121/20
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
165 words
A rotary file comprising a circular filing wheel, a base, a fixed vertical shaft secured in said base and extending upwardly therefRom, bearing and support means between said filing wheel and said base for rotatably mounting said wheel around said shaft above said base at a substantially fixed vertical distance therefrom, a magnetic plate secured to the bottom of said wheel, support means secured in said base around said shaft, a plurality of studs projecting upward from said support means, an annular electromagnet disposed around said shaft and normally resting on said support means, said electromagnet having apertures therein in which respective studs are received, whereby said electromagnet is limited in movement to a vertical direction toward and away from said magnetic plate, and means for providing electrical energy to said electromagnet to activate the same, said electromagnet, upon activation, being attracted to and frictionally engageable with said magnetic plate, such that friction between said electromagnet and said plate brakes rotary movement of said wheel.
Claim 2
Dependent Claim
165 words
A rotary file comprising a circular filing wheel, a base, a fixed vertical shaft secured in said base and extending upwardly therefRom, bearing and support means between said filing wheel and said base for rotatably mounting said wheel around said shaft above said base at a substantially fixed vertical distance therefrom, a magnetic plate secured to the bottom of said wheel, support means secured in said base around said shaft, a plurality of studs projecting upward from said support means, an annular electromagnet disposed around said shaft and normally resting on said support means, said electromagnet having apertures therein in which respective studs are received, whereby said electromagnet is limited in movement to a vertical direction toward and away from said magnetic plate, and means for providing electrical energy to said electromagnet to activate the same, said electromagnet, upon activation, being attracted to and frictionally engageable with said magnetic plate, such that friction between said electromagnet and said plate brakes rotary movement of said wheel.
Claim 3
Dependent Claim
54 words
The rotary file of claim 1 wherein said means for providing electrical energy to said electromagnet comprises an electrical circuit connected thereto, and a plurality of switches connected in parallel in said circuit, said switches being provided at spaced locations around said wheel to allow braking of said wheel from each of said locations.
Claim 4
Dependent Claim
53 words
The rotary file of claim 2 wherein control means are provided in said circuit for regulating current through said electromagnet, said control means comprising a triac connected in said series in said circuit, a source of voltage connected to the gate of said triac, and means for regulating the voltage to said gate.
Claim 5
Dependent Claim
99 words
A rotary file comprising a filing wheel, a base beneath said wheel, means for rotatably mounting said wheel over said base, brake means supported upon said base and movable into engagement with said wheel, said brake means comprising an electromagnet having an upwardly facing pole face and means on said base for confining movement of said electromagnet to a direction toward and away from said wheel, a plate composed of a magnetic material is mounted on the bottom of said wheel and is engageable by said electromagnet, and means for energizing said electromagnet from various positions around said wheel.
Claim 6
Dependent Claim
99 words
A rotary file comprising a filing wheel, a base beneath said wheel, means for rotatably mounting said wheel over said base, brake means supported upon said base and movable into engagement with said wheel, said brake means comprising an electromagnet having an upwardly facing pole face and means on said base for confining movement of said electromagnet to a direction toward and away from said wheel, a plate composed of a magnetic material is mounted on the bottom of said wheel and is engageable by said electromagnet, and means for energizing said electromagnet from various positions around said wheel.
Claim 7
Dependent Claim
28 words
The rotary file of claim 4 whprein means are provided for adjusting the flow of current through said electromagnet for regulating the degree of braking force applied thereby.
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) | 1976-09-03 | 1977-03-05 | 1977-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-03 | 1981-03-05 | 1981-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-03 | 1985-03-05 | 1985-09-04 | $7700.00 | Window Closed / Lapsed |