IMPROVEMENTS IN SAFETY LIGHTERS AND APPARATUS FOR IGNITING CHARGES FOR BLASTING PURPOSES
Year: 1873

page_text: LETTERS PATENT to Simon Davey, Manufacturer of Safety Fuse, and
James Watson, Civil Engineer, both of Rouen, France, for the
Invention of "IMPROVEMENTS IN SAFETY LIGHTERS AND APPARATUS For
Scaled the 30th September 1873, and dated the 5th April 1873.
PROVISIONAL SPECIFICATION left by the said Simon Davey and
James Watson at the Office of the Commissioners of Patents, with
their Petition, on the 5th April 1878.
We, SIMON DAVEY, Manufacturer of Safety Fuse, and JAMES WATSON,
Civil Engineer, both of Rouen, France, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN SAFETY LIGHTERS AND APPARATUS
FOR IGNITING CHARGES FOR BLASTING PURPOSES," to be as follows:-

page_text: ignition at the will of the miner, and forming a sort of capsule or
covering to the end of the fuse, preventing any escape of sparks or
flame, yet suitably ventilated to allow of the safe exit of the heated gases
produced by the ignition.
Secondly. To attaching such tube in a secure manner to the end of t
the safety fuse.
Thirdly. To the application of percussion caps or fulminates to the
lighting of safety fuse.
Fourthly. To the use of needles or metallic rods with or without
springs for safely igniting the said caps.
Fifthly. The ventilating of the tube by a contrivance of a chamber
or chambers communicating with each other or with the external
atmosphere only through sufficiently small apertures or interstices,
giving the same protection against the passage of flame as in the Davy
lamp, such interstices to be preferably through metallic surfaces, whether
in wire gauze or in pierced or creased metal.
Sixthly. The use of a lighting charge within such tube, whether
fixed to the end of the safety fuse or introduced as a disc or wad within
the tube.
Seventhly. The use of sulphuric acid and chlorate of potash for
the purpose of obtaining ignition without percussion caps within the
tube.
Eighthly. The application to the lighting of safety fuse of metallic
cartridge cases, such as are used for fire-arms with the requisite additions
and adaptations, as described.
Ninthly. The use in combination with our safety lighter of a special
strongly made taped fuse, so prepared as that no spark or fire can come
through its outer envelope; and for distinction's sake we prefer to make
the same of a yellow colour, employing non-inflammable materials, such
as aluminous or siliceous paste, in the manufacture of such paste between
the tissues which compose its envelope, and on the outer surface thereof,
but with the distinctive yellow colour.
Tenthly. The use of a proper tool or tools for the purpose of the chief
miner to give the ignition when desired, whether by a hammer or
needle, or both, with or without a spring movement or a properly

page_text: graduated recipient to drop sulphuric acid into an orifice protected, all
as herein-after described.
Our Invention provides a means of communicating to any blasting
charge the necessary ignition without any flame, spark, or reddened
surface being used or visible externally, thus removing as far as is possible.
all danger of accidents from fire in mines, where this our Invention is
exclusively to be employed for the lighting of the various shots required,
and wherein consequently no matches, open flames, or other dangerous
means should on any account whatever be allowed.
We employ for this purpose a specially prepared tape safety fuse, as
shown in the accompanying Drawings, Figures 1 and 2, which we reserve
to ourselves the right to supply and vend with the safety lighters, also
shown, this special safety fuse A, made with care, and of the strongest and
best materials only, is of a yellow colour, so that it may be readily distin-
guished from any inferior or weak safety fuse unsuitable for our purpose.
The inner end of the safety fuse is introduced in the usual manner into
the blasting charge, and is tamped up carefully. On the outer end is
securely fixed our safety lighter B, which consists of a tube a so adapted
to the safety fuse as to effectually cover and protect the end thereof, and
to allow the smoke or vapour produced by the combustion to escape
without any sparks or danger of any kind.
The safety lighter tube a is preferably in the form of a rifle cartridge
case, the rear 6 thereof being metallic, and the remainder c in strong
double pasteboard of the best and strongest construction, and lined with
copper d. In the rear of the tube a percussion cap is fixed in a metallic
chamber, protected by compressed pasteboard e within the metallic end
of the tube, and a small metal rod f, Figures 1, 2, and 4, is introduced
therein for the purpose of igniting the cap in the usual way when
desired. In front of the percussion cap we place a small lighting charge g,
preferably in the form of a disc of paper or linen, covered with powder
paste, and the end of the safety fuse A is made to abut against this disc
or nearly so.
Around the safety fuse and within the external tube is an elastic
packing of pasteboard and thin metal h, so arranged as that by external
35 compression at one, two, or more places a chamber (or chambers) is formed
between the compressions, and the metal lining is at the same time

page_text: corrugated into narrow plaits or folds, between which folds the smoke,
vapours, or gases of combustion make their exit from chamber to chamber
with perfect freedom, but at the same time through a series of small
interstices repeated at each compression, as in Figure 3, and giving in
each instance the same security against the passage of fire or flame as is
afforded by the wire gauze of the Davy lamp.
As a special security against any movement or displacement of our
safety lighters from the end of the safety fuse we fix it firmly thereto by
a metallic pin, rivet, or nail, so that the contents and internal arrange-
ment may not be tampered with before using, and so that by no possibility
can the force of the issuing gases blow off the safety lighter at the time
of ignition.
The shot is fired by the chief miner only, who is provided for the
purpose with a sort of pistol butt and lock, as in Figure 5, but with an
open guide seat i and slot ; to receive the safety lighter in the place of
the ordinary barrel of the arm.
We reserve to ourselves to supply and vend these arms with the safety
lighters wherever needed, also to vary the external form or arrangement
of the materials employed or the materials themselves, but so as always
to secure a thoroughly strong and incombustible outer case, with secure
means of escape for the gases within through small interstices, and to
firmly fix the same by rivets, pins, clips, or ties to the suitable strong
safety fuse.
We also reserve to ourselves the right to vary the mode of ignition,
replacing the percussion cap by frictional surfaces properly prepared and
charged, to be actuated from without by percussion by twisting, by
pushing, or by dragging, whether with rods, bands, or strings; also the
use of suitably prepared chlorate pastes, to be fired by the introduction of
a drop or drops of sulphuric acid, as described with reference to Figures 6
and 7, änd in such case the introduction thereof through suitably pro-
tected orifices with small interstices and air chambers between, so that
no flame can issue thereby; also the supply of proper and safe recipients
for containing and dropping the sulphuric acid.
The action of this is as follows:-The screw plug D being raised
causes the small groove in its side to rise above the rim of the recipient C,

page_text: thereby admitting air through the said groove into the upper portion of
recipient C, and so allowing a drop or drops of acid to fall from the hole
in the lower portion of O into the funnel e, fixed on the upper side of
cartridge case, and containing two distinct wire gauze linings k and I,
through which the acid percolates to reach the threads m, smeared with
a paste composed of chlorate of potash contained in a special metallic
charge chamber, in front of which is the disc charge g near end of fuse.
But for reasons of economy in manufacture and the perfection already
attained in the manufacture of metallic cartridge cases for fire-arms, we
purpose at least in the first instance, and where not especially required
otherwise, to use the same as herein-before described.
We likewise reserve to ourselves the substituting for the pistol butt
and lock any other means of piercing or igniting the cap within the
safety lighter, whether by any arrangement of a spring (or springs)
acting on a needle to pierce the said cap, such needle either fixed to
such spring or independent thereof, or by any snap, hammer, or other
percussive means, but in every case so as that no spark shall escape
when the ignition takes place.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Simon Davey and James Watson in the Great
Seal Patent Office on the 4th October 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, SIMON
DAVEY, Manufacturer of Safety Fuse, and JAMES WATSON, Civil
Engineer, both of Rouen, France, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifth day of April, in the year of our
Lord One thousand eight hundred and seventy-three, in the thirty-
sixth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto us, the said Simon Davey and James Watson, Her
special licence that we, the said Simon Davey and James Watson, our
executors, administrators, and assigns, or such others as we, the said
Simon Davey and James Watson, our executors, administrators, and
assigns, should at any time agree with, and no others, from time to

page_text: time and at all times thereafter during the term therein expressed,
should and lawfully might make, use, exercise, and vend, within the
United Kingdom of Great Britain and Ireland, the Channel Islands,
and Isle of Man, an Invention for "IMPROVEMENTS IN SAFETY LIGHTERS
AND APPARATUS FOR IGNITING CHARGES FOR BLASTING PURPOSES," upon the 5
condition (amongst others) that we, the said Simon Davey and James
Watson, or one of us, our executors or administrators, by an instrument
in writing under our, or one of our or their, or one of their hands and
seals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and 1
cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that we, the said Simon Davey and James Watson,
do hereby declare the nature of our said Invention, and in what ]
manner the same is to be performed, to be particularly described and
ascertained in and by the following statement thereof, reference being
had to the Drawings hereunto annexed, that is to say :-
Our Invention provides a means of communicating to any blasting
charge the necessary ignition without any flame, spark, or reddened a
surface being used or visible externally, thus removing as far as is
possible all danger of accidents from fire in mines, where this our
Invention is exclusively to be employed for the lighting of the various
shots required, and wherein consequently no matches, open flames, or
other dangerous means should on any account whatever be allowed.
We employ for this purpose a specially prepared tape safety fuze, as
shown in the accompanying Drawings, Figures 1 and 2, which we
reserve to ourselves the right to supply and vend with the safety
lighters, also shown. This special safety fuze A, made with care and
of the strongest and best materials only, is of a yellow colour, so that it
may be readily distinguished from any inferior or weak safety fuze
unsuitable for our purpose. The inner end of the safety fuze is intro-
duced in the usual manner into the blasting charge, and is tamped up
carefully. On the outer end is securely fixed our safety lighter B, which
consists of a tube a, so adapted to the safety fuze as to effectually cover
and protect the end thereof, and to allow the smoke or vapour produced
by the combustion to escape without any sparks or danger of any kind.

page_text: The safety lighter tube a is preferably in the form of a rifle cartridge
case, the rear 6 thereof being metallic, and the remainder o in strong
double pasteboard of the best and strongest construction, and lined with
copper d. In the rear of the tube a percussion cap is fixed in a metallio
chamber, protected by compressed pasteboard e within the metallic end
of the tube, and a small metal rod f, Figures 1, 2, and 4, is introduced
therein for the purpose of igniting the cap in the usual way when
desired. In front of the percussion cap we place a small lighting
charge g, preferably in the form of a disc, of paper or linen covered with
powder paste, and the end of the safety fuze A is made to abut against
this disc, or nearly so.
Around the safety fuse and within the external tube is an elastic
packing of pasteboard and thin metal h, so arranged as that by external
compression at one, two, or more places a chamber (or chambers) is
formed between the compressions, and the metal lining is at the same
time corrugated into narrow plaits or folds, between which folds the
smoke, vapours, or gases of combustion make their exit from chamber to
chamber with perfect freedom, but at the same time through a series of
small interstices repeated at each compression, as in Figure 3, and giving
in each instance the same security against the passage of fire or flame as
is afforded by the wire gauze of the Davy lamp.
As a special security against any movement or displacement of our
safety lighters from the end of the safety fuze, we fix it firmly thereto
by a metallic pin, rivet, or nail, so that the contents and internal
arrangement may not be tampered with before using, and so that by no
possibility can the force of the issuing gases blow off the safety lighter at
the time of ignition.
The shot is fired by the chief miner only, who is provided for the
purpose with a sort of pistol butt and lock, as in Figure 5, but with an
open guide seat i and slot j to receive the safety lighter in the place of
the ordinary barrel of the arm.
We reserve to ourselves to supply and vend these arms with the safety
lighters wherever needed; also to vary the external form or arrangement
of the materials employed or the materials themselves, but so as always
to secure a thoroughly strong and incombustible outer case, with secure
means of escape for the gases within through small interstices, and to

page_text: firmly fix the same by rivets, pins, clips, or ties to the suitable strong
safety fuze.
We also reserve to ourselves the right to vary the mode of ignition,
replacing the percussion cap by frictional surfaces properly prepared
and charged, to be actuated from without by percussion, by twisting, by
pushing, or by dragging, whether with rods, bands, or strings; also the
use of suitably prepared chlorate pastes, to be fired by the introduction
of a drop or drops of sulphuric acid, as described with reference to
Figures 6 and 7, and in such case the introduction thereof through
suitably protected orifices with small interstices and air chamber
between, so that no flame can issue thereby; also the supply of proper
and safe recipients for containing and dropping the sulphuric acid.
The action of this is as follows:-The screw plug D being raised
causes the small groove in its side to rise above the rim of the reci-
pient C, thereby admitting air through the said groove into the upper
portion of recipient C, and so allowing a drop or drops of acid to fall
from the hole in the lower portion of O into the funnel E, fixed on the
upper side of cartridge case, and containing two distinct wire gauze
linings / and 1, through which the acid percolates to reach the threads m,
smeared with a paste composed of chlorate of potash, contained in
a special metallic charge chamber, in front of which is the disc charge g
near end of fuze. But for reasons of economy in manufacture, and the
perfection already attained in the manufacture of metallic cartridge
cases for fire-arms, we propose, at least in the first instance and
when not special required otherwise, to use the same as herein-before
described.
We likewise reserve to ourselves the substituting for the pistol butt
and lock any other means of piercing or igniting the cap within the
safety lighter, whether by any arrangement of a spring (or springs)
acting on a needle to pierce the said cap, such needle either fixed to such
spring or independent thereof, or by any snap, hammer, or other per-
cussive means; but in every case so as that no spark shall escape when
the ignition takes place.
We specially claim as essential or component parts of this our In-
vention of safety lighters for mines,-
1. The application to the end of a proper safety fuze of a tube closed
9

page_text: at the outer end, such tube containing within itself the means of ignition
at the will of the miner, and forming a sort of capsule or covering to
the end of the fuze, preventing any escape of sparks or flame, yet
suitably ventilated to allow of the safe exit of the heated gases produced
by the ignition.
at the outer end, such tube containing within itself the means of ignition
at the will of the miner, and forming a sort of capsule or covering to
the end of the fuze, preventing any escape of sparks or flame, yet
suitably ventilated to allow of the safe exit of the heated gases produced
by the ignition.
2. The attaching such tube in a secure manner to the end of the safety
fuze.
3. The application of percussion caps or fulminates to the lighting of
safety fuze.
4. The use of needles or metallic rods, with or without springs, for
safely igniting the said caps.
5. The ventilating of the tube by the contrivance of a chamber or
chambers communicating with each other or with the external atmo-
sphere only through sufficiently small apertures or interstices, giving the
same protection against the passage of flame as in the Davy lamp, such
interstices to be preferably through metallic surfaces, whether in wire
gauze, or in pierced or creased metal.
6. The use of a lighting charge within such tube, whether fixed to the
end of the safety fuze or introduced as a disc or wad within the tube.
7. The use of sulphuric acid and chlorate of potash for the purpose of
obtaining ignition without percussion caps within the tubes.
8. The application to the lighting of safety fuze of metallic cartridge
cases, such as are used for fire-arms, with the requisite additions and
adaptations, as described.
9. The use in combination with our safety lighter of a special strongly
made taped fuze, so prepared that no spark or fire can come through its
outer envelope; and for distinction's sake we prefer to make the same
of a yellow colour, employing non-inflammable materials, such as alu-
minous or siliceous paste in the manufacture of such fuse between the
tissues which compose its envelope and on the outer surface thereof, but
with the distinctive yellow colour.
10. The use of a proper tool or tools for the purpose of the chief miner
to give the ignition when desired, whether by a hammer or needle or
both, with or without a spring movement, or a properly graduated

page_text: recipient to drop sulphuric acid into an orifice, protected all as herein-
before described.
In witness whereof, we, the said James Watson and the said Simon
Davey, have hereunto set our hands and seals, this Second day of
October One thousand eight hundred and seventy-three.
S. DAVEY. (L.S.) JAS. WATSON. (L.S.)