through Shot-firing in Mines.
Year: 1884

page_text: through Shot-firing in Mines.
I, FREDERICK AUGUSTUS ABEL, Knight, of the Royal Arsenal Woolwich in the
County of Kent, Chemist to the War Department, do hereby declare the nature
of my invention for "IMPROVED METHOD OF AND APPLIANCES FOR PREVENTING
ACCIDENTS THROUGH SHOT-FIRING IN MINES" to be as follows:-
My invention has for its object the attainment of security against the possible
ignition of fire-damp or of explosive mixtures of fire-damp and air in mines by the
operation known as "shot-firing," and it consists in causing the explosion of the firing
charge in the blast hole to effect the liberation of a charge of gas, such as carbonic
acid or nitrogen, that will not support combustion, such charge being contained in
a compressed or condensed condition in a suitable casing, within or in close
proximity to which the explosive charge is situated.
Such charge of compressed gas, being liberated by the explosion, readily expands
so as to fill the space surrounding the seat of the explosion, thereby either
displacing the immediately surrounding air or gaseous mixture, or mixing with it
in such proportions as to render it incapable of supporting combustion or of igniting
or exploding, while at the same time any flame or incandescent solid matter
resulting from the explosion is immediately extinguished by envelopment in or
projection into the expanding gas released thereby.
Various arrangements may be adopted for carrying my said invention into
practice; thus according to one arrangement, a vessel, by preference cylindrical,
having closed ends, the one solid and the other removeable, and being of such a
diameter as to admit of its introduction into the bore hole and of a length
proportional to the charge employed, is constructed of wrought iron, steel, phosphor-
bronze or other suitable metal or alloy of adequate strength to resist the pressure
exercised by the condensed gas with which it is to be partially charged.
The cylinder or cartridge is provided at its solid end with a removeable
perforated screw plug serving to receive the union of the pipe leading either to the
reservoir of condensed gas with which the cylinder is to be charged, or to n
compressing pump by means of which the gas is compressed directly in the
cylinder. Inside the cylinder at this end is placed a leather disc serving as a check'
valve for preventing the escape of the compressed gas from the charging hole or
perforation, while the perforated screw plug is being removed and replaced by
a solid one. The other end of the cylindrical vessel, which is in the form of a

page_text: removeable wrought iron screw plug, is provided with a conical perforation to
receive a plug of gutta percha or other suitablo material. It carries a fuze or the
electrical wires leading to the detonator contained in the confined charge of
explosive, and which, being conical inwards, forms a gas tight joint or plug. The
operation of preparing this cylinder for use is as follows:-
The explosive charge having been fitted with its detonator and fuze or electrical
wires enclosed in insulation in the well known manner, the conical plug of gutta
percha or other suitable material is fitted upon the fuse or wire conductor. The
removeable plug-end is then removed from the cylinder or cartridge and the gutta
percha plug is inserted into the perforation in the plug-end, the charge is introduced
into the cartridge and the plug is replaced and screwed home tightly. The
cylinder or cartridge is then connected at the other end with the apparatus for
charging it with condensed gas, which by preference would be either carbonic acid
or nitrogen, and when the operation of filling with gas is completed, the perforated
plug is removed and replaced by the solid screw plug. The cartridge is then ready
for use, being inserted into the blast hole with or without the superposition of
tamping applied in the ordinary manner. According to another arrangement the
explosive charge, instead of being contained within the cylinder containing the
compressed gas, is arranged in an extension at the rear end of the cylinder,
the fuze or electric wires being passed through a passage formed in the side of the
cylinder containing the compressed gas. Or, according to another arrangement
the chamber containing the explosive charge is placed at the front end of the
cylinder containing the compressed gas.
ABEL & IMRAY,
Agents for the Applicant,
28, Southampton Buildings,
London, W.C.
improveй мешой отани арриансса IV1 IIOVсны ду
through Shot-firing in Mines.
I, FREDERICK AUGUSTUS ABEL, Knight, of the Royal Arsenal Woolwich in the
County of Kent, Chemist to the War Department, do hereby declare the nature of
this invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
My invention has for its object the attainment of security against the possible
ignition of fire-damp or of explosive mixtures of fire-damp and air in mines by the
operation known as shot-firing, and it consists in causing the explosion of the firing

page_text: charge in the blast hole to effect the liberation of a charge of gas, such as carbonic
acid or nitrogen, that will not support combustion, such charge being contained in
a compressed or condensed condition in a suitable casing, within or in close
proximity to which the explosive charge is situated.
Such charge of compressed or condensed gas, being liberated by the explosion,
readily expands so as to fill the space surrounding the seat of the explosion, thereby
either displacing the immediately surrounding air or gaseous mixture, or mixing
with it in such proportions as to render it incapable of supporting combustion or
of igniting or exploding, while at the same time any flame or incandescent solid
matter resulting from the explosion is immediately extinguished by envelopement
in or projection into the expanding gas released thereby.
Various arrangements may be adopted for carrying my said invention into
practice; thus according to one arrangement, a vessel, by preference cylindrical,
having closed ends, the one solid and the other removeable, and being of such a
diameter as to admit of its introduction into the bore hole and of a length
proportional to the charge employed, is constructed of wrought iron, steel, phosphor
bronze or other suitable metal or alloy of arlequate strength to resist the pressure
exercised by the condensed gas with which it is to be charged.
The cylinder or cartridge is provided at its solid end with a removeable
perforated screw plug serving to receive the union of the pipe leading either to
the reservoir of condensed gas with which the cylinder is to be charged, or to a
compressing pump by means of which the gas is compressed directly in the
cylinder. Inside the cylinder at this end is placed a leather disc serving as a check
valve for preventing the escape of the gas from the charging hole or perforation
while the perforated screw plug is being removed and replaced by a solid one.
The other end of the cylindrical vessel, which is in the form of a removeable
wrought iron screw plug, is provided with a conical perforation to receive a plug
of gutta percha or other suitable material. It carries a fuze or the electrical wires
leading to the detonator contained in the confined charge of explosive, and which
being conical inwards forms a gas-tight joint or plug. The operation of preparing
this cylinder for use is as follows:-
The
The explosive charge having been fitted with its detonator and fuze or electrical
wires enclosed in insulation in the well known manner, the conical plug of gutta
percha or other suitable material is fitted upon the fuze or wire conductor. The
removeable plug-end is then removed from the cylinder or cartridge and the gutta
percha plug is inserted into the perforation in the plug-end, the charge is introduced
into the cartridge and the plug is replaced and screwed home tightly.
cylinder or cartridge is then connected at the other end with the apparatus for
charging it with condensed gas, which by preference would be either carbonic acid
or nitrogen, and when the operation of filling with gas is completed, the perforated
plug is removed and replaced by the solid screw plug. The cartridge is then
ready for use, being inserted into the blast hole with or without the superposition
of tamping applied in the ordinary manner. According to another arrangement
the explosive charge instead of being contained within the cylinder containing
the gas, is arranged in an extension at the rear end of the cylinder, the fuze or
electric wires being either outside the cylinder, between it and the wall of the
blast hole or passed through a passage formed in the side of the cylinder containing
the gas; or the cylinder containing the gas may be quite separate from the blasting
charge, which may be introduced into the blast hole in the ordinary manner either
above or below the gas cylinder, or between two gas cylinders.
The accompanying drawing shows various arrangements for carrying out my
before described invention. In the longitudinal section shewn at Fig. 1 A is a
cylindrical vessel containing the condensed gas, within one end of which is formed
a chamber B containing the blasting charge; this chamber is closed at its outer
end by a plug C having a hole through which pass the clectrical wires or fuze
connected to the detonator. The cylinder A is provided at its other end with a
nozzle D screwed into it, through which it is charged with the condensed gas.

page_text: For this purpose the nozzle is provided with a passage D' through which the gas
passes into the cylinder when the nozzle is connected to a charging reservoir or
forcing pump by a union screwed on at D³; at D³ is provided a screw plug, which,
when the vessel is charged with gas, is screwed inwards so as to close the
passage D¹ in a gas-tight manner before disconnecting the vessel from the reservoir.
In the longitudinal section shewn at Fig. 2, the chamber B containing the
blasting charge is formed as an extension of the gas cylinder A instead of within
it; the partition E is brazed or otherwise secured in a coned seating, so that the
pressure of the gas will tend to tighten it outwards, while on the explosion of the
blasting charge it will be readily forced inwards. The construction is otherwise
the same as at Fig. 1.
Fig. 3 shews a section of a cylinder for containing the condensed gas, to be used
separate from the blasting charge, which is placed in close contiguity thereto, so
as to effect its disruption by the explosion. The nozzle D is in this case provided
with a flexible flap valve D' for automatically closing the charging passage D¹,
which is in addition closed by a screw-plug D³ when the vessel is disconnected
from the charging reservoir or pump.
This construction may also be employed for containing the blasting charge
immediately within the gas receptacle as before described; in this case the end of
the gas cylinder A would be closed with a screwed plug D, as shewn at Fig. 4,
which is removed for the introduction of the blasting charge, before the cylinder
is charged with gas, and which has a tapering hole for the reception of a conical
plug F of gutta percha or other suitable material, through which pass the electrical
wires of the blasting charge. The pressure of the gas tightens the plug F in its
hole and also round the wires G so as to form a perfectly gas-tight joint.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is
1. Preventing the ignition of inflammable or explosive gases in mines by causing
the explosion of a firing charge to liberate condensed gas confined in contiguity
thereto, such gas being of a nature that will not support combustion.
2. The use in combination with a firing charge for blasting purposes, of a
receptacle containing condensed gas of a nature that will not support combustion,
substantially as and for the purposes herein described.