Patent US5099762A successfully refreshed from Google Patents.
US5099762A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrostatic discharge immune electric initiator
Assignee: Special Devices Inc
•
Filing: 1990-12-05
•
Granted: 1992-03-31
•
Expires: 2010-12-05
Abstract
Abstract An electro-explosive initiator which may be either a coaxial or floating case type, for example, and which is constructed to be immune from the effects of electrostatic discharges. The initiator includes a bridgewire and contact pins for carrying an electric igniting signal to the bridgewire. The initiator has a discrete capacitor connected across the contact pins to shunt out the energy resulting from an electrostatic discharge pulse, and for preventing such energy from reaching the bridgewire.
Inventors
- 👤 Thaddeus R. Drapala
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 15:57
CPC Classifications
F; F42; F42B; F42B3/00; F42B3/10; F42B3/18; F42B3/182; F42B3/188
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
167 words
An electro-explosive initiator constructed to be immune from electro-static discharge pulses resulting from ambient electro-static fields encountered by the initiator, said initiator comprising: a casing; an explosive charge mounted within said casing; a bridgewire mounted within said casing for igniting said charge in response to an electric current through said bridgewire; first and second terminal pins directly connected to said bridgewire for supplying an electric current to said bridgewire for igniting said explosive charge; first and second leads; first and second splice members respectively connecting said leads to said first and second pins; and a discrete capacitor having a capacity substantially in the range of 0.1 microfarad to 10.0 microfared, said capacitor having first and second lead wires respectively connected to said leads to said first and second splice members whereby substantially all of the energy of an electro-static discharge pulse resulting from an ambient electro-static field encountered by the initiator is shunted so as to prevent energy resulting from said discharge pulse from reaching the bridgewire.
Claim 2
Dependent Claim
167 words
An electro-explosive initiator constructed to be immune from electro-static discharge pulses resulting from ambient electro-static fields encountered by the initiator, said initiator comprising: a casing; an explosive charge mounted within said casing; a bridgewire mounted within said casing for igniting said charge in response to an electric current through said bridgewire; first and second terminal pins directly connected to said bridgewire for supplying an electric current to said bridgewire for igniting said explosive charge; first and second leads; first and second splice members respectively connecting said leads to said first and second pins; and a discrete capacitor having a capacity substantially in the range of 0.1 microfarad to 10.0 microfared, said capacitor having first and second lead wires respectively connected to said leads to said first and second splice members whereby substantially all of the energy of an electro-static discharge pulse resulting from an ambient electro-static field encountered by the initiator is shunted so as to prevent energy resulting from said discharge pulse from reaching the bridgewire.
Claim 3
Dependent Claim
24 words
The initiator defined in claim 1, in which said lead wires of said capacitor are resistance welded to said first and second splice members.
Claim 4
Dependent Claim
17 words
The initiator defined in claim 1, in which said capacitor capacity of the order of 0.33 microfarads.
Claim 5
Dependent Claim
20 words
The initiator defined in claim 1, in which said capacitor has a voltage rating of the order of 50 Volts.
Claim 6
Dependent Claim
36 words
The initiator defined in claim 1, and which includes a radio frequency filter interposed between said first and second terminal pins to absorb radio frequency signals and prevent spurious ignition of the initiator by such signals.
References Cited (Backward Citations)
US2802421A
Cited
US2818020A
Cited
US3018733A
Cited
US3180262A
Cited
US3343491A
Cited
US3306202A
Cited
US3572247A
Cited
US3640224A
Cited
US3804018A
Cited
US3783788A
Cited
US3966224A
Cited
US3793954A
Cited
US4261263A
Cited
US4378738A
Cited
US4384734A
Cited
US4438424A
Cited
US4592280A
Cited
US4933570A
Cited
US4938504A
Cited
US4845377A
Cited
US4944224A
Cited
US4851705A
Cited
US4893109A
Cited
US4967665A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-03-31 | 1995-09-30 | 1996-03-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-03-31 | 1999-09-30 | 2000-03-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-03-31 | 2003-09-30 | 2004-03-31 | $7700.00 | Window Closed / Lapsed |