IMPROVEMENTS IN CAPS OR PRIMING FOR MINE CARTRIDGES AND OTHER SIMILAR PURPOSES
Year: 1880

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields, in the
County of Middlesex, Gentleman, for an Invention of "IMPROVEMENTS IN
CAPS OR PRIMING FOR MINE CARTRIDGES AND OTHER SIMILAR PURPOSES." A
communication from abroad by Eugène François Désiré Ruggieri, of Paris, in
the Republic of France.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at the
Office of the Commissioners of Patents on the 3rd March 1880.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN CAPS OR PRIMING FOR MINE CARTRIDGES AND
OTHER SIMILAR PURPOSES." A communication from abroad by Eugène François
Désiré Ruggieri, of Paris, in the Republic of France.
This Invention has for its chief objects the production of a cap or priming, by
means of which the blasting charge of a mine may be exploded without the employ-
ment of a light, and also preventing the projection of fame to the exterior when
the priming is ignited. The Invention is particularly adapted for use in mines
subject to fire damp; but it is also applicable otherwise for blasting purposes, and
to the caps and cartridges used for fire arms.
In carrying out the said Invention as applied to the explosion of cartridges for
blasting purposes the apparatus is constructed in the following manner, viz. -A
tube is employed (by preference of copper) one end of which is closed but formed
with a central orifice for the passage of a rod carrying a serrated extremity for the
ignition of the fulminate by friction. The fulminate is contained within an internal
central tube which is surrounded with a card board tube, the latter being in its
turn enclosed by the external tube before referred to, and the rod of the igniter
also passes through the centre of the fulminate. Within the external tube, at its
base or outer end, and between it and the end of the fulminate tube, is placed sand
stone powder, pulverised glass, or any other suitable inert matter contained between
two washers of india rubber or other suitable material, the whole forming a tight
joint so as to prevent the egress of flame to the exterior at the time of igniting the
fulminate

page_text: The washer nearest to the igniter bears against a shoulder formed by a con-
traction of the external tube for the purpose of preventing this washer from
compressing the pulverised material contained between the washers, as hereinbefore
described, and rendering the same too compact when the rod of the igniter is
pulled. The external tube is mounted upon a cardboard cylinder of the requisite
length containing a central quick match.
In carrying out the operations of blasting the cap thus constructed is fixed at
the entrance of a hole in the mine charged in the ordinary manner, and the rod of
the igniter (which may be operated by means of a cord from a distance) is pulled,
whereby the fulminate is ignited under the action of the serrated extremity of the
rod. The match is thus lighted and projected to the end of the hole in the mine,
thus exploding the charge of powder, whilst by the mode of maintaining a tight
joint hereinbefore described any escape of the flame from the ignition of the
fulminate is entirely prevented.
The details of the cap will necessarily be somewhat modified when it is used
for the explosion of cartridges in small arms and ordnance, but the principle and
method of securing a light joint, herein before described, are retained.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Henry Johnson in the Great Seal Patent Office on the 26th
August 1880.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN CAPS OR PRIMING FOR MINE CARTRIDGES AND
OTHER SIMILAR PURPOSES." A communication from abroad by Eugène François
Désiré Ruggieri, of Paris, in the Republic of France.
The said Invention has for its chief objects the production of a cap or priming,
by means of which the blasting charge of a mine may be exploded without the
employment of a light, and also the prevention of the egress of flame to the exterior
when the priming is ignited. The Invention is particularly adapted for use in
mines subject to fire damp, but is also applicable otherwise for blasting purposes,
and to the caps and cartridges used for fire arms.
And in order that the said Invention may be fully understood, I shall now
proceed more particularly to describe the same, and for that purpose shall refer to
the several Figures on the annexed Sheet of Drawings, the same letters of reference
indicating corresponding parts in the Figures.
Figure 1 of the accompanying Drawings represents a longitudinal section of an
apparatus constructed according to the said Invention, and adapted for blasting
purposes; Figure 2 is another longitudinal section of the same apparatus, the
section being taken at right angles to the section in Figure 1; and Figure 3 is a
corresponding elevation.
This igniting apparatus is composed of a copper tube a, the end b of which is
formed with a central orifice for the passage of a rod c carrying a serrated
extremity & for the ignition of the fulminate by friction. An internal central
tube e contains a certain quantity of fulminate g, and is surrounded with a card
board tube f, the latter being in its turn enclosed by the external tube a, and the
rod of the igniter passes through the centre of the fulminate g. Within the
external tube a, at its base or outer end, and between it and the end of the fulminate
tube e is placed a packing h of sand stone powder, pulverized glass, or any other
suitable inert matter contained between two washers i and j of india rubber or
other suitable material, the whole forming a tight joint so as to prevent the egress
of flame to exterior at the time of igniting the fulminate. The washer j nearest to
the igniter bears against a shoulder o formed by a contraction of the external
tube a for the purpose of preventing this washer from compressing the pulverized
material contained between the washers i and ), and rendering the same too
compact when the rod of the igniter is pulled. The external tube a is mounted
upon a card board cylinder k of the requisite length containing a central quick
match l
In carrying out the operations of blasting the cap thus constructed is fixed at
the entrance of a hole charged in the ordinary manner, and the rod c of the igniter d
(which may be operated from a distance by means of a cord attached to a ring m)
is pulled, whereby the fulminate g is ignited under the action of the serrated
extremity or igniter_d_of_the_rod c. The match-l-is-thus-lighted,-and-the-flame-
is conducted to the end of the hole, thus exploding the charge of powder, whilst by
the mode of maintaining a tight joint, herein before described, any escape of the
flame from the ignition of the fulminate is entirely prevented.
The details of the cap will necessarily be somewhat modified when it is used for
the explosion of charges or cartridges in small arms and ordnance, but the principle
and method of securing a tight joint, herein before described, are retained.
By means of the said Invention the objectionable discharge of flame from
the rear part of a cap or cartridge is entirely obviated, and considerable advantage
is thereby obtained in working heavy guns and guns for artillery.

page_text: Having now described and particularly ascertained the nature of the said
Invention and the manner in which the same is or may be used or carried into
effect, I would observe in conclusion that what I consider to be novel and original,
and therefore claim as the Invention secured to me by the hereinbefore in part
recited Letters Patent is,-
The improved cap or priming for mine cartridges and other similar purposes, the
said cap or priming having the peculiar packing herein mentioned, and being
constructed and arranged generally, substantially in the manner hereinbefore
described.
In witness whereof, I, the said John Henry Johnson, have to this my Specifi-
cation set my hand and seal, this Twenty third day of August, One thousand
eight hundred and eighty.
J. HENRY JOHNSON. (L.s.)