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Title: Shotgun cartridge rock breaker

Abstract

A rock breaker uses shotgun cartridges or other firearm ammunition as the explosive charge at the bottom of a drilled borehole. The breaker includes a heavy steel rod or bar, a gun with a firing chamber for the ammunition which screws onto the rod, a long firing pin running through a central passage in the rod, and a firing trigger mechanism at the external end of the bar which strikes the firing pin to fire the cartridge within the borehole. A tubular sleeve surround the main body of the rod and includes slits the end to allow it to expand. The rod has a conical taper at the internal end against which the end of the sleeve expands when the sleeve is forced along the rod toward the taper by a nut threaded onto the external end of the rod. As the sleeve end expands, it pushes against the borehole and holds the explosive gasses within, and also prevents the breaker from flying out of the borehole. The trigger mechanism includes a hammer with a slot and a hole for accepting a drawbar or drawpin which, when pulled by a long cord, allows the cartridge to be fired from amore » remote location.« less

Inventors:
 [1];  [2]
  1. Eagan, NM
  2. Bloomington, MN
Issue Date:
Research Org.:
National Energy Technology Laboratory, Pittsburgh, PA, and Morgantown, WV
OSTI Identifier:
870200
Patent Number(s):
5474364
Assignee:
United States of America as represented by Secretary of (Washington, DC)
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
shotgun; cartridge; rock; breaker; cartridges; firearm; ammunition; explosive; charge; bottom; drilled; borehole; heavy; steel; rod; bar; gun; firing; chamber; screws; running; central; passage; trigger; mechanism; external; strikes; fire; tubular; sleeve; surround; main; slits; allow; expand; conical; taper; internal; expands; forced; nut; threaded; pushes; holds; gasses; prevents; flying; hammer; slot; accepting; drawbar; drawpin; pulled; cord; allows; fired; remote; location; central passage; steel rod; explosive charge; remote location; trigger mechanism; tubular sleeve; rock breaker; shotgun cartridge; sleeve surround; conical taper; /299/102/

Citation Formats

Ruzzi, Peter L, and Morrell, Roger J. Shotgun cartridge rock breaker. United States: N. p., 1995. Web.
Ruzzi, Peter L, & Morrell, Roger J. Shotgun cartridge rock breaker. United States.
Ruzzi, Peter L, and Morrell, Roger J. Sun . "Shotgun cartridge rock breaker". United States. https://www.osti.gov/servlets/purl/870200.
@article{osti_870200,
title = {Shotgun cartridge rock breaker},
author = {Ruzzi, Peter L and Morrell, Roger J},
abstractNote = {A rock breaker uses shotgun cartridges or other firearm ammunition as the explosive charge at the bottom of a drilled borehole. The breaker includes a heavy steel rod or bar, a gun with a firing chamber for the ammunition which screws onto the rod, a long firing pin running through a central passage in the rod, and a firing trigger mechanism at the external end of the bar which strikes the firing pin to fire the cartridge within the borehole. A tubular sleeve surround the main body of the rod and includes slits the end to allow it to expand. The rod has a conical taper at the internal end against which the end of the sleeve expands when the sleeve is forced along the rod toward the taper by a nut threaded onto the external end of the rod. As the sleeve end expands, it pushes against the borehole and holds the explosive gasses within, and also prevents the breaker from flying out of the borehole. The trigger mechanism includes a hammer with a slot and a hole for accepting a drawbar or drawpin which, when pulled by a long cord, allows the cartridge to be fired from a remote location.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1995},
month = {1}
}

Patent:

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