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US3713384A Expired / Lapsed US ⏱️ 0.0 years remaining

Blasting method

Assignee: Imperial Chemical Industries Ltd
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Filing: 1970-03-23
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Granted: 1973-01-30
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Expires: 1990-03-23
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Abstract

Abstract A blasting method and primer assembly for blasting agents wherein the primer assembly comprises a high explosive priming charge, a connector and an intermediate length of detonating cord, the connector being adapted to hold the detonating cord in close lengthwise proximity to and slidably movable along a downline of detonating cord.

Inventors

  • 👤 B Turnbull

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 17:37
CPC Classifications
F; F42; F42D; F42D1/00; F42D1/04

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 144 words
A primer assembly for initiating a blasting agent which comprises a priming charge of high explosive, a connecting length of detonating cord attached at one end in detonation transmission relationship to the said explosive charge, and a connector attached to the other end of said connecting length for slidably connecting the assembly of priming charge and connecting length to a downline of detonating cord, said connector comprising a body member having bore means therethrough which surround a portion of said connecting length, the bore means having a longitudinal wall portion adapted to slidably engage a downline of detonating cord when the latter is inserted through said bore means and said bore means having a further longitudinal wall portion firmly holding said connecting length and positioning the same in parallel detonating relationship with the downline when the latter has been inserted through the bore means.
Claim 2
Dependent Claim 144 words
A primer assembly for initiating a blasting agent which comprises a priming charge of high explosive, a connecting length of detonating cord attached at one end in detonation transmission relationship to the said explosive charge, and a connector attached to the other end of said connecting length for slidably connecting the assembly of priming charge and connecting length to a downline of detonating cord, said connector comprising a body member having bore means therethrough which surround a portion of said connecting length, the bore means having a longitudinal wall portion adapted to slidably engage a downline of detonating cord when the latter is inserted through said bore means and said bore means having a further longitudinal wall portion firmly holding said connecting length and positioning the same in parallel detonating relationship with the downline when the latter has been inserted through the bore means.
Claim 3
Dependent Claim 29 words
A primer assembly as claimed in claim 1 wherein the connector is formed with two substantially parallel bores to accommodate the downline and connecting length of detonating cord respectively.
Claim 4
Dependent Claim 34 words
A primer assembly as claimed in claim 2 wherein the bores overlap in cross-section to provide direct communication between the bores and to permit the downline and connecting length to be held in contact.
Claim 5
Dependent Claim 41 words
A primer assembly as claimed in claim 1 wherein the body member of the connector is provided with a chamber into which the end of the connecting length may be inserted after being drawn through the body member and doubled backwards.
Claim 6
Dependent Claim 18 words
A primer assembly as claimed in claim 1 wherein the body member is formed from synthetic plastics material.
Claim 7
Dependent Claim 23 words
A primer assembly as claimed in claim 1 wherein the priming charge is a castable explosive which is cast around the detonating cord.
Claim 8
Dependent Claim 34 words
A primer assembly as claimed in claim 1 wherein the end of the detonating cord intended for connection to the downline is covered by a waterproofing composition comprising silicone-rubber and/or a metal end cap.
Claim 9
Dependent Claim 39 words
A primer assembly as claimed in claim 1 wherein the priming composition comprises cast or pressed Pentolite consisting of PETN and TNT in a ratio of 40:60 to 60:40 by weiGht tetryl, cyclotrimethylenetrinitramine or mixtures of cyclotrimethylenetrinitramine and TNT.

References Cited (Backward Citations)

No citation records indexed.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1976-01-30 1976-07-31 1977-01-30 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1980-01-30 1980-07-31 1981-01-30 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1984-01-30 1984-07-31 1985-01-30 $7700.00 Window Closed / Lapsed

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