Patent US3724174A successfully refreshed from Google Patents.
US3724174A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrically operated dust mask
Assignee: Bergwerksverband GmbH
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Filing: 1970-09-28
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Granted: 1973-04-03
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Expires: 1990-09-28
Abstract
Abstract A breathing filter for dust filtering masks in which electrodes in the form of insulated metal wires are employed. The polarity of the electrodes changes in periods which are of greater duration than the duration of dust particles in the filter, but is less than the time required for equalizing the difference in potential of the electrodes. Hardly any electrical energy is used so that a source of voltage of low yield can be used.
Inventors
- 👤 W Walkenhorst
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:52
CPC Classifications
B; B03; B03C; B03C3/00; B03C3/32; Y; Y10; Y10S; Y10S55/00; Y10S55/35
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
161 words
Breathing filter especially for dust masks, for the separation of dust particles from gases comprising a plurality of frames arranged in superposed relation, positively and negatively charged electrodes on each frame, said electrodes comprising two similar layers of metal wires extending back and forth between the sides of each frame, the wires of one layer being charged positively and those wires of the other layer being negatively charged, a moisture-repellent insulating coating for each of said wires, each wire being of a diameter of approximately 0.1 mm. and wires of different polarity being spaced approximately 0.5 mm., hills and valleys on the surface of said wires for the reinforced non-homogenization of the electric field, and spacers separating one frame from another, whereby the polarity of the electrodes may be changed in periods which are greater than the duration of the dust particles in the filter but less than the time rEquired for the equalization of the potential difference of the electrodes.
Claim 2
Dependent Claim
161 words
Breathing filter especially for dust masks, for the separation of dust particles from gases comprising a plurality of frames arranged in superposed relation, positively and negatively charged electrodes on each frame, said electrodes comprising two similar layers of metal wires extending back and forth between the sides of each frame, the wires of one layer being charged positively and those wires of the other layer being negatively charged, a moisture-repellent insulating coating for each of said wires, each wire being of a diameter of approximately 0.1 mm. and wires of different polarity being spaced approximately 0.5 mm., hills and valleys on the surface of said wires for the reinforced non-homogenization of the electric field, and spacers separating one frame from another, whereby the polarity of the electrodes may be changed in periods which are greater than the duration of the dust particles in the filter but less than the time rEquired for the equalization of the potential difference of the electrodes.
Claim 3
Dependent Claim
15 words
Breathing filter according to claim 1, in which the wire layers are harp-like in arrangement.
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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) | 1976-04-02 | 1976-10-02 | 1977-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-02 | 1980-10-02 | 1981-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-02 | 1984-10-02 | 1985-04-03 | $7700.00 | Window Closed / Lapsed |