US3589081A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Abrading method
Assignee: Pennwalt Corp
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Filing: 1969-06-03
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Granted: 1971-06-29
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Expires: 1989-06-03
Abstract
Abstract Miniature electrical resistors having a resistive film on a nonconductive substrate are abrasively trimmed to increase their resistance to a desired value by moving an abrasive jet between the resistor terminals, while measuring the rate of resistance increase, and then stopping and reversing the movement of the jet at a projected point in time when resistance has increased to the desired value. Capacitors and other electrical elements can be trimmed by this method.
Inventors
- 👤 Walter Kilischenko
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:53
CPC Classifications
H; H01; H01C; H01C17/00; H01C17/22; H01C17/24; H01C17/245; B; B24; B24C; B24C3/00; B24C3/02; B24C3/06; B24C3/32; B24C3/322
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
137 words
In a method of adjusting to a desired value the electrical value of an electrical element comprising a film on a nonconductive substrate bridging spaced terminals, by abrading a portion of said film with abrasive particles having a nozzle as a source, the steps of: a. holding element in a workpiece holder, b. providing a high velocity jet of airborne abrasive particles, c. directing said jet toward the film at close range, d. moving said jet linearly in a first direction across part of said film in a path between said terminals to reduce the crosssectional area of said film between said terminals, e. stopping and reversing the movement of said jet upon reaching the desired electrical value of said element at a faster rate of travel during reverse movement than during movement in Said first direction.
Claim 2
Dependent Claim
137 words
In a method of adjusting to a desired value the electrical value of an electrical element comprising a film on a nonconductive substrate bridging spaced terminals, by abrading a portion of said film with abrasive particles having a nozzle as a source, the steps of: a. holding element in a workpiece holder, b. providing a high velocity jet of airborne abrasive particles, c. directing said jet toward the film at close range, d. moving said jet linearly in a first direction across part of said film in a path between said terminals to reduce the crosssectional area of said film between said terminals, e. stopping and reversing the movement of said jet upon reaching the desired electrical value of said element at a faster rate of travel during reverse movement than during movement in Said first direction.
Claim 3
Dependent Claim
30 words
A method according to claim 1 wherein said film is electrically resistive, conductive material, the electrical resistance of which is increased by reducing the cross-sectional area thereof between said terminals.
Claim 4
Dependent Claim
33 words
The method according to claim 1 wherein the moving of said jet in step (d) is performed at a constant rate of travel with a constant distance between said film and the nozzle.
Claim 5
Dependent Claim
77 words
The method according to claim 1 wherein said step of providing a high velocity jet of airborne abrasive particles includes mixing pressurized air and a stream of abrasive particles in a mixing chamber, further including vibrating said mixing chamber at a constant frequency of vibration, and setting the concentration of abrasive particles in said jet by adjusting the amplitude of vibration applied to said mixing chamber in direct relation to the desired abrasive capability of said jet.
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) | 1974-06-28 | 1974-12-28 | 1975-06-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-28 | 1978-12-28 | 1979-06-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-28 | 1982-12-28 | 1983-06-29 | $7700.00 | Window Closed / Lapsed |