US4294648A
Expired / Lapsed
US
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Method for increasing the resistance of igniter elements of given geometry
Assignee: Dynamit Nobel AG
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Filing: 1980-02-26
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Granted: 1981-10-13
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Expires: 2000-02-26
Abstract
Abstract A method for increasing the resistance of an igniter element of given geometry in an electrical circuit to a predetermined, specific value by the removal of resistance material, which comprises heating the resistance material situated between two acid-resistance electrodes simultaneously etching the resistance material with acid until the desired resistance value has been established.
Inventors
- 👤 Uwe Brede
- 👤 Heinz Kern
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 10:10
CPC Classifications
F; F42; F42B; F42B3/00; F42B3/10; F42B3/103; F42B3/12; F42B3/128; H; H01; H01C; H01C17/00; H01C17/22; H01C17/24; H01C17/2416
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
54 words
A method for increasing the resistance of an igniter element of given geometry in an electrical circuit to a predetermined, specific value by the removal of resistance material, which comprises heating the resistance material situated between two acid-resistance electrodes simultaneously etching the resistance material with acid until the desired resistance value has been established.
Claim 2
Independent Claim
54 words
A method for increasing the resistance of an igniter element of given geometry in an electrical circuit to a predetermined, specific value by the removal of resistance material, which comprises heating the resistance material situated between two acid-resistance electrodes simultaneously etching the resistance material with acid until the desired resistance value has been established.
Claim 3
Dependent Claim
27 words
A method according to claim 1, wherein the resistance material is heated electrically and the current flow is shut off after the desired resistance value is reached.
Claim 4
Dependent Claim
21 words
A method according to claim 1, wherein the resistance value of the resistance material is measured continuously during the acid treatment.
Claim 5
Dependent Claim
34 words
A method according to claim 1, wherein the acid treatment is performed with the aid of an absorbent material carrying the acid and the resistance material so ablated is absorbed by the absorbent material.
Claim 6
Dependent Claim
46 words
A method according to claim 4, wherein the absorbent material carrying the acid is moved in a gliding or rubbing movement on the resistance material by means of a plunger, until, after the desired resistance value is reached, it is lifted away from the resistance material.
Claim 7
Dependent Claim
13 words
A method according to claim 4, wherein felt is used as absorbent material.
Claim 8
Dependent Claim
15 words
A method according to claim 1, wherein dilute nitric acid is used as the acid.
References Cited (Backward Citations)
US3860465A
Cited
US4188258A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-10-12 | 1985-04-13 | 1985-10-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-10-12 | 1989-04-13 | 1989-10-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-10-12 | 1993-04-13 | 1993-10-13 | $7700.00 | Window Closed / Lapsed |