Improved Method of Obtaining Increased Safety in Shot Firing in Coal and other Mines.
Year: 1898

page_text: Improved Method of Obtaining Increased Safety in Shot Firing in
Coal and other Mines.
We, CHARLES HERBERT CURTIS, of the Firm of Curtis's & Harvey, of 74, Lom-
bard Street, London, Gunpowder Manufacturers, DAVID JAMES METCALFE, a
Managing Director of John Hall & Son Limited, of 79, Cannon Street, London,
Gunpowder Manufacturers, and ANDREW FULLER HARGREAVES, General Manager,
and ALFRED COPLEY PEARCY, London Manager of Hay, Merricks & Co. Limited,
of Roslin, Midlothian, Gunpowder Manufacturers, do hereby declare the nature
of this invention to be as follows;
-
According to our invention we provide suitable means for manufacturing,
treating or using gunpowder, or other explosive blasting charges, so that by extin-
guishing the flame or incandescent particles of the said explosive and lowering
the temperature of the same when fired increased safety is obtained.
We find that such increased safety is obtained by the use of bicarbonate of potash
(K.H.C.O) and such substance may be used either by the same being incorporated
with the gunpowder or other explosive in process of its manufacture or may be
used by mixing crystals of the same of suitable size with the finished gunpowder
or other explosive after manufacture, or such substance may be used separated
and intact from the gunpowder or other explosive, being either combined in a
cartridge, and preferably so that the said bicarbonate of potash and the said
explosive are not formed into a mixture but are kept separate or intact from each
other either by the use of a diaphragm or the like in those cases where it is
desirable that the extinguishing or cooling substance should be kept separate from
the explosive, or used as an addition to the explosive either loose or in pellets or
any other suitable form
first tamping, or in any other suitable
or desired manner. Bicarbonate of potash for this purpose possesses
many advantages, amongst others it is of considerable density and hard-
ness, it is stable and neither efflorescent nor deliquescent, while it gives off
carbonic acid gas in desirable quantities for the purposes named. The quantity
of such bicarbonate of potash which we find it is desirable to use may vary but we
find that it should not exceed about 50 per cent. of the weight of the gunpowder
or other explosive used but such proportion may be decreased.
as a
Dated this 2nd day of June 1898.
THEO. MCKENNA,
17 and 18, Basinghall Street, London, E.C.,
Applicants' Agent.

page_text: Improved Method of Obtaining Increased Safety in Shot Firing in
Coal and other Mines.
We, CHARLES HERBERT CURTIS, of the Firm of Curtis's & Harvey, of 74, Lom-
bard Street, London, Gunpowder Manufacturers, DAVID JAMES METCALFE, a
Managing Director of John Hall & Son Limited, of 79, Cannon Street, London,
Gunpowder Manufacturers, and ANDREW FULLER HARGREAVES, General Manager,
and ALFRED COPLEY PEARCY, London Manager of Hay, Merricks & Co. Limited,
of Roslin, Midlothian, Gunpowder Manufacturers, do hereby declare the nature
of this invention and in what manner the same is to be performed, to be particu-
larly described and ascertained in and by the following statement:-
According to our invention we provide suitable means for manufacturing treat-
ing or using gunpowder or other like explosive blasting charges so that by extin-
guishing the flame or incandescent particles of the said explosive and lowering the
temperature of the same when fired increased safety is obtained.
We find that such increased safety is obtained by the use of bicarbonate of
potash (K.H.C.03) and such substance may be used either by the same being
incorporated with the gunpowder or other like explosive in process of its manu-
facture or it may be used by mixing crystals of the same of suitable size with the
finished gunpowder or other like explosive after manufacture or such substance
may be used separated and intact from the gunpowder or other like explosive
being either combined in a cartridge so that the bicarbonate of potash and the
said explosive are kept separate or intact from each other by the use of a diaphragm
or the like or used either loose or in pellets or in any other suitable form as a
first tamping or otherwise as an addition to the explosive-in any suitable manner
for the purpose of extinguishing or cooling the flame from the cartridge. When
the bicarbonate of potash is to be used as a cooling agent separate from the explo-
sive charge but combined in the same cartridge therewith it may with advantage
be placed in the receptacle for cooling material provided in the cartridge which
is described in the Specification of a former patent granted to us and Clement
Leigh Watson Smith being No. 232 of the year 1898. When using the said
material as crystals we find the most suitable size to be such as will pass through
a sieve of 6 mesh but we do not limit ourselves to such size. Bicarbonate of potash
for this purpose possesses many advantages amongst others it is of considerable density
and hardness it is stable and neither efflorescent nor deliquescent while it gives off
carbonic acid gas in desirable quantities for the purposes named. The quantity
of such bicarbonate of potash which we find it is desirable to use may vary but we
find that when used with the explosive it should not exceed about 50 per cent. of
the weight of the gunpowder or other like explosive used nor fall short of about
33 per cent of the weight thereof. When used separate from the explosive charge
the bicarbonate of potash may be used in larger quantities.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is:-
1. The employment in connection with gunpowder or other blasting explosive
charge of a like kind of a cooling agent for extinguishing the flame or incan-
descent particles of the said explosive consisting of bicarbonate of potash
(K.H.C.O) incorporated with the explosive in process of its manufacture or mixed
as crystals with the finished explosive after manufacture the bicarbonate of potash

page_text: being added to the explosive in form and proportion substantially as hereinbefore
described.
2. The employment in connection with gunpowder or other explosive blasting
charge of a like kind of a cooling agent for extinguishing the flame or incandescent
particles of the said explosive such cooling agent consisting of a permeable mass
of bicarbonate of potash (K.H.C.O3) kept separate and intact from the gunpowder
or other like explosive blasting charge & contained in a separate compartment
within the cartridge substantially as herein before described.
3. The employment in connection with gunpowder or other explosive blasting
charge of a like kind of a cooling agent for extinguishing the Hame or incan-
descent particles of the said explosive such cooling agent consisting of a permeable
mass of bicarbonate of potash (K.H.C.O) tamped in front of the cartridge in the
bore hole substantially as hereinbefore described.
4. The employment for the purpose of the cooling agent mentioned above in
the 2nd and 3rd claiming clauses of a permeable pellet of bicarbonate of potash
(K.H.C.O) composed of crystals of the kind hereinbefore described adhering to
one another so as to form a coherent mass.
THEO. MCKENNA,
17 and 18, Basinghall Street, London, Patent Agent.