US4961065A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fail-safe resistor
Assignee: CTS Corp
•
Filing: 1989-03-27
•
Granted: 1990-10-02
•
Expires: 2009-03-27
Abstract
Abstract An electrical resistor is formed upon the substrate. The substrate is laser scribed, preformed, or notched in such a way as to control accurately the breakage of the substrate dependent upon the thermal stress load produced by the resistor. By varying the position of the scribe or notch, the device can be programmed to repeatably shatter at an infinite number of time-load points. The method for applying this technique is also described for other substates or configurations.
Inventors
- 👤 Eric B. Taylor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 05:49
CPC Classifications
H; H01; H01H; H01H85/00; H01H85/02; H01H85/04; H01H85/041; H01H85/048; H01C; H01C1/00; H01C1/01; H01C1/012; H01H85/0039; H01H85/0073
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
109 words
A fail-safe resistor comprising: a relatively electrically non-conductive frangible substrate; a means for conducting electricity, said conducting means being thermally coupled to said substrate; a flaw within or upon said substrate, said flaw having one of multiple possible predetermined controlled dimension and multiple possible predetermined position combinations relative to said substrate; whereby a predictable time duration for a particular power dissipation in said conducting means is required and sufficient to cause a break in said frangible substrate and to cause electrical discontinuity of said conducting means, said time duration dependent upon which one of said multiple controlled dimension and position combinations is further combined with said particular power dissipation.
Claim 2
Dependent Claim
109 words
A fail-safe resistor comprising: a relatively electrically non-conductive frangible substrate; a means for conducting electricity, said conducting means being thermally coupled to said substrate; a flaw within or upon said substrate, said flaw having one of multiple possible predetermined controlled dimension and multiple possible predetermined position combinations relative to said substrate; whereby a predictable time duration for a particular power dissipation in said conducting means is required and sufficient to cause a break in said frangible substrate and to cause electrical discontinuity of said conducting means, said time duration dependent upon which one of said multiple controlled dimension and position combinations is further combined with said particular power dissipation.
Claim 3
Dependent Claim
29 words
The fail-safe resistor of claim 1 wherein said substrate is comprised by a material which is relatively strong in compressive strength and which is relatively weak in tensile strength.
Claim 4
Dependent Claim
34 words
The fail-safe resistor of claim 2 wherein said flaw is dimensioned and positioned at the exterior perimeter of said substrate, said flaw extending a relatively small distance towards an interior region of said substrate.
Claim 5
Dependent Claim
73 words
A fail-safe resistor comprising a relatively electrically non-conductive fracturable substrate, a relatively electrically conductive material thermally and physically coupled to said substrate, and a means for regulating the amount and duration of thermal energy required to fracture said substrate and simultaneously fracture said relatively electrically conductive material, said amount and duration of said thermal energy required governed and variable by alteration of a predetermined position of said regulating means relative to said substrate.
Claim 6
Dependent Claim
73 words
A fail-safe resistor comprising a relatively electrically non-conductive fracturable substrate, a relatively electrically conductive material thermally and physically coupled to said substrate, and a means for regulating the amount and duration of thermal energy required to fracture said substrate and simultaneously fracture said relatively electrically conductive material, said amount and duration of said thermal energy required governed and variable by alteration of a predetermined position of said regulating means relative to said substrate.
Claim 7
Dependent Claim
30 words
The fail-safe resistor of claim 4 wherein said means for regulating the amount and duration of thermal energy required is not in physical or electrical contact with said electrical conductor.
References Cited (Backward Citations)
US2263752A
Cited
US2730598A
Cited
US3836883A
Cited
US3978443A
Cited
US4134096A
Cited
US4208645A
Cited
US4263574A
Cited
US4315235A
Cited
US4494104A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-10-01 | 1994-04-02 | 1994-10-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-10-01 | 1998-04-02 | 1998-10-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-10-01 | 2002-04-02 | 2002-10-02 | $7700.00 | Window Closed / Lapsed |