Shotgun cartridge rock breaker
- Eagan, NM
- Bloomington, MN
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.
- Research Organization:
- National Energy Technology Laboratory (NETL), Pittsburgh, PA, Morgantown, WV (United States)
- Assignee:
- United States of America as represented by Secretary of (Washington, DC)
- Patent Number(s):
- US 5474364
- OSTI ID:
- 870200
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
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
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