US3754506A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spark gap detonator
Assignee: United States Atomic Energy Commission
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Filing: 1971-05-07
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Granted: 1973-08-28
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Expires: 1991-05-07
Abstract
Abstract An improved spark gap detonator having a central electrode and surrounding annular electrode which project into a recess formed in one end of the detonator cavity. When explosive powder is pressed into the cavity, the powder flowing past the projecting annular electrode experiences an abrupt pressure drop such that the powder filling the recess packs at a lower density than the powder in the rest of the detonator cavity. This allows the detonator to be filled with only a single powder pressing, while providing a relatively low density powder, which is easier to detonate, adjacent the electrodes, and whereby the electrode configuration has a lower inductance, resulting in a shorter rise time of the firing voltage and hence improved timing of detonation.
Inventors
- 👤 R Parker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:45
CPC Classifications
F; F42; F42B; F42B3/00; F42B3/10; F42B3/14
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
169 words
A spark gap detonator comprising: a body means defining a chamber therein, said body means comprising a pair of sleeve-like members, one of said pair of sleeve-like members being operatively secured within a countersunk portion of the other of said pair of sleeve-like members, annular electrode means secured in said body means intermediate said pair of sleeve-like members and projecting radially and annularly into said chamber partially dividing said chamber into two sections, said annular electrode having a radially projecting inner periphery of a cross-section less than cross-sections of said two sections of said chamber, central electrode means insulatively secured within said body means in spaced relation with respect to said radially projecting annular electrode means defining an annular space therebetween and extending through at least one of said two sections of said chamber, and explosive powder contained in said chamber, said explosive powder in said one of said two sections of said chamber being at a lower density than the explosive powder in the remainder of said chamber.
Claim 2
Dependent Claim
169 words
A spark gap detonator comprising: a body means defining a chamber therein, said body means comprising a pair of sleeve-like members, one of said pair of sleeve-like members being operatively secured within a countersunk portion of the other of said pair of sleeve-like members, annular electrode means secured in said body means intermediate said pair of sleeve-like members and projecting radially and annularly into said chamber partially dividing said chamber into two sections, said annular electrode having a radially projecting inner periphery of a cross-section less than cross-sections of said two sections of said chamber, central electrode means insulatively secured within said body means in spaced relation with respect to said radially projecting annular electrode means defining an annular space therebetween and extending through at least one of said two sections of said chamber, and explosive powder contained in said chamber, said explosive powder in said one of said two sections of said chamber being at a lower density than the explosive powder in the remainder of said chamber.
Claim 3
Dependent Claim
24 words
The spark gap detonator defined in claim 1, wherein said annular electrode means is electrically connected to one of said pair of sleeve-like members.
Claim 4
Dependent Claim
31 words
The spark gap detonator defined in claim 1, wherein said central electrode means is insulatively secured in an insulator member, said insulator member being secured in one of said sleeve-like members.
Claim 5
Dependent Claim
42 words
The spark gap detonator defined in claim 3, wherein said insulator member is provided with a cavity at the end thereof adjacent said annular electrode means, said cavity having a larger cross-section than the inner periphery cross-section of said annular electrode means.
Claim 6
Dependent Claim
154 words
The spark gap detonator defined in claim 1, wherein said pair of sleeve-like members are constructed so as to contain a substantially identical internal diameter, wherein said annular electrode means is secured intermediate an end of said one of said pair of sleeve-like members and a shoulder portion of said countersunk portion of said other of said pair of sleeve-like members, wherein said central electrode means is insulatively secured in an insulator member secured in said one of said sleeve-like member, said insulator member being positioned in substantial abuttment with said annular electrode means and containing a cavity in the portion thereof adjacent said annular electrode means defining said one of said two sections of said chamber and having a diameter larger than the inner periphery cross-section of said annular electrode means, said central electrode extending through said insulator member, said cavity in said insulator member and at least through said annular electrode means.
Claim 7
Dependent Claim
24 words
The spark gap detonator defined in claim 5, wherein said annular electrode is electrically connected to said one of said pair of sleeve-like members.
Claim 8
Independent Claim
186 words
A method of manufacturing a spark gap detonator utilizing a single explosive powder pressing operation comprising the steps of: forming a detonator cavity, positioning an annular electrode means in radially and annularly projecting relationship with respect to the cavity dividing the cavity into two sections having croSs-sections larger than the inner periphery cross-section of the annular electrode means, positioning a central electrode means in the cavity so as to extend through one of the two sections thereof and in spaced relationship with respect to the radially projecting annular electrode means, electrically insulting the central electrode means from the annular electrode means, and pressing explosive powder into the cavity with the powder flowing past the annular projecting edge of the annular electrode experiencing an abrupt pressure drop such that the powder filling the section of the cavity through which the central electrode extends is at a density lower than the density of the powder filling the other section of the cavity, whereby a spark between the central electrode means and the annular electrode means detonates the lower density explosive powder which detonates the higher density explosive powder.
Claim 9
Independent Claim
186 words
A method of manufacturing a spark gap detonator utilizing a single explosive powder pressing operation comprising the steps of: forming a detonator cavity, positioning an annular electrode means in radially and annularly projecting relationship with respect to the cavity dividing the cavity into two sections having croSs-sections larger than the inner periphery cross-section of the annular electrode means, positioning a central electrode means in the cavity so as to extend through one of the two sections thereof and in spaced relationship with respect to the radially projecting annular electrode means, electrically insulting the central electrode means from the annular electrode means, and pressing explosive powder into the cavity with the powder flowing past the annular projecting edge of the annular electrode experiencing an abrupt pressure drop such that the powder filling the section of the cavity through which the central electrode extends is at a density lower than the density of the powder filling the other section of the cavity, whereby a spark between the central electrode means and the annular electrode means detonates the lower density explosive powder which detonates the higher density explosive powder.
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) | 1976-08-27 | 1977-02-26 | 1977-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-27 | 1981-02-26 | 1981-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-27 | 1985-02-26 | 1985-08-28 | $7700.00 | Window Closed / Lapsed |