Improvements in and relating to Electric Primers or Igniters for Blasting or Firing Mines, Torpedoes, Guns, and the like.
Year: 1888

page_text: Date of Application, 28th Dec., 1888
Complete Specification Left, 27th Sept., 1889-Accepted, 16th Nov., 1889°
PROVISIONAL SPECIFICATION.
Improvements in and relating to Electric Primers or Igniters for
Blasting or Firing Mines, Torpedoes, Guns, and the like.
We, EDMUND LOUIS ZALINSKI. Captain of Artillery United States Army, stationed
at the City, County and State of New York, and HENRY JULIUS SMITH, Electrician,
residing at Pompton, in the County of Passaic and State of New Jersey, United
States of America, do hereby declare the nature of said invention to be as follows:-
Detonators such as are used in firing dynamite and similar cartridges are well known
and procurable in most mining regions. Usually such consist of a thin metallic tube,
which tube contains a small charge of fulminate of mercury.
Primers or detonators so constructed are however dangerous to transport the object
of this invention being to avoid this danger by keeping the igniting or initial charge
separate from the detonator.
To this end the invention consists in a primer in which the igniting or initial charge
is kept separate from the detonator.
This may be accomplished by connecting the insulated wire ends by a fine platinuu
filament or bridge that becomes highly heated with the passage of an electric current
and said wires are held rigidly apart by any suitable means, such as a clamp. The
bridge and wire ends are or may be coated or covered with fulminate of mercury,
the wires so connected and provided with the fulminate may then be embedded in a
block of powder first rendered plastic and then compressed around the wire ends.
A safer primer may be obtained by embedding the wires in a block of sulphur or a
material or a compound of such fusible at a low temperature may be employed.
The block of sulphur or other material may be coated with rubber or a varnish to
render the primer water-proof.
In submarine mining the wires and charge may be coated with rubber, varnish, or
the like, as an extra precaution to exclude moisture.
When desirable a delay can be had in the explosion of the primer by interposing a
delay match between the igniter and detonator, this match may be of wood, plaster or
other material constructed to receive the detonator and a charge of slow burning
powder to convey fire from the igniter to the detonator.
This construction is of advantage in quarrying and mining when it is frequently
desirable to drill a number of holes around a central core and after blowing out or
breaking this core to explode other charges around it. It is difficult if not
impossible to prepare all these successive charges for firing by electricity in the
ordinary manner, as the explosion of the first charge is likely to disarrange the wires
or break the bridges of the other charges.
Dotad ibis 28th 1.1000
EDMUND LOUIS ZALINSKI.
HENRY JULIUS SMITH.
By Jensen & Son,
77. Chancery Lane, London, W.C., Patent Agents.
COMPLETE SPECIFICATION.
Improvements in and relating to Electric Primers or Igniters for
Blasting or Firing Mines, Torpedoes, Guns, and the like.
We, EDMUND LOUIS ZALINSKI, Captain of Artillery, United States Army, stationed
at the City, County, and State of Now York, and HENRY JULIUS SMITH, Electrician,
residing at Pompton, in the County of Passaic, and State of New Jersey, United
States of America, do hereby declare the nature of this invention, and in what manner
D

page_text: the same is to be performed, to be particularly described and ascertained in and
by the following statement:-
The invention consists. in a primer in which the igniting or initial charge is
kept separate from the detonator, so that the primers, which contain very small
quantities of suitable inflammable or explosive material, can be transported without
danger. The platinum bridge of the igniter is supported in the inflammable or
explosive material and when desirable a delay can be bad in the explosion of the
detonator after the igniter is fired. As suitable inflammable or explosive may be
mentioned compressed gun-cotton, fulminute of mercury; or mixtures thereof with
gun-cotton or gunpowder. In some cases where required by reason of legal restriction
such gunpowder or other mixtures are used as are permitted for unrestricted or less
restricted transport than the first named materials.
Detonators such as are used in firing dynamite and similar cartridges are well
known and procurable in most mining regions. Usually such consist of a thin
metallic tube, as at A, Figures 5 and 6, which tubes contain a small charge, B, of
fulminate of mercury.
Referring to the accompanying drawings
Figure 1 is a side elevation and cross section of the primer wires and connections.
Figure 2, similar views of a primer, with the initial charge enclosed in a cake of
compressed powder.
Figure 3, similar views indicating the position of the wires, initial charge, and
double waterproof coating.
Figure 4, similar views of a primer with single waterproof coating.
Figure 5, primer and section of detonator with interposed delay action squib.
Figure 6 primer and section of detonator.
Figure 7 is an end view to illustrate the application of a number of delay action
primers in connection with a quick acting prinier arranged as for tunnelling or similar
blasting operations.
Letters a, a, indicate the usual conducting or battery wires. These wires are con-
nected by a fine filament or bridge b, shown in figure i of platinum or other material
which becomes highly heated with the passage of an electric current.
The wires are insulated by any usual covering c, and held at a suitable distance
apart, near the end, by a small metallic clasp d, Figure 1 or by stitching or winding
figure 2. Of course the wires a will be insulated from each other, save as electric
connection is made by bridge, b, this bridge being soldered to the wires.
The clasp d, figure 1, or the stitching fig. 2 holds the wires a, a, rigidly at a little
distance apart. The bridge is very delicate, and must be protected against breakage
as far as possible. A coating, e, of fulminate of mercury and collodion or other
suitable inflammable material as previously mentioned is applied to the bridge and the
ends of the wires by dipping the ends of the wires into the material while the latter is
in a plastic state.
The end of the primer may now be enclosed in a block of powder (Figure 2)
the latter being compressed on the primer while moist and afterwards dried. The
primer thus made is easily transportable, and there is little danger of breaking the
bridge.
A safer igniter, 1), however, is made by enclosing the ends of the wires and igniter
or match, e, in a block of sulphur, g, Figure 4, the same being melted and cast
around the wires. A compound of plaster, or papier maché, or metal which fuses
at a low temperature may be used, but sulphur has been found to answer exceedingly
well.
The sulphur may be provided with a coating of rubber or varnish, h, easily
applied by dipping. This makes a good water-proofing and serves to attach the
igniter to the detonator when applied as in figure 6. Or instead of rubber or
varnish the sulphur may he dipped in melted wax of various descriptions of a water-
proofing nature.
When the igniters D, are to be used in submarine mining or such work where extra
precaution to exclude moisture is required, the wires and charge, e, may as shewn in

page_text: figure receive a coating of varnish, rubber, paraffine; or other waterproofing
materiali, before the application of sulphur g.
Igniters constructed as described and shown in Figures 3 and 4, may be shipped
in bundles, and are so safe from explosion that one may be fired without
exploding another in the bundle.
In quarrying and mining it is frequently desirable to drill a number of holes
around a central core, and after blowing out or breaking up this core to explode
other charges around it. It is difficult or impossible to prepare all these successive
charges for firing by electricity in the ordinary manner, as the explosion of the
first charge is likely to disarrange or break the conducting wires. It also causes
delay as some time must necessarily elapse, if in a tunnel, mine, or other confined
space, before the noxious gases generated by an explosion are dissipated and the
miner can enter without danger of suffocation or other injurious effect.
Figure shews a delay action match which is interposed between the igniter D
and the detonator A. This match E may be a block of wood, plaster, or other
suitable material m, having a recess; n, to receive the igniter, a projection. o, to enter
the detonator, and a charge of slow burning powder, to convey fire from the
igniter to the detonator. These delay action matches can be placed in connection
with all of the outer charges of a blast, while the inner charges are fired instan-
taneously by the same electric circuit. All the igniters will be fired at once by
closing the circuit with an electrical battery or exploding machine. The central
charge or charges will explode at once, but the igniters in the outer circles will
only ignite the matches, which in turn will fire the detonators. This delay action
will generally be for only the small fraction of a second. The block m, may have
vent holes m', which are preferably closed with paraffin, in which the whole block
may be dipped. The upper surface of the slow match should be covered by an
easily ignited priming material in order to ensure ignition from the igniter.
Primers constructed in the manner described will be available for use in any
number on an electric circuit limited only by the strength of the current used and the
sensitiveness of the primer and the resistance of the circuit. The conditions of
resistance of each bridge and of the surrounding material being the same,
the ignition
of all the initial charges will be simultaneous.
In Figure 7 the central primer Qis of the construction shown in Figure 6 whilst
the primers RR arranged around it are of the construction shown in Figure 5. All
the primers and Rare connected up on a single electrical firing circuit and upon
the current being sent through the same the primer Q explodes its charge and causes
an initial shattering or breaking at the centre. At the same instant however the
primers RR, have also ignited but owing to the delay action contained in them they
do not at once ignite or explode their respective charges but do so some very short
space of time after the central cartridge has done its shattering work; we thus
obtain a larger shattering effect with a given charge than if as heretofore all the
charges were exploded simultaneously.
Sometimes where it is desirable to have a succession of delays in order to produce
successive firings delay action primers with different lengths of slow match are
employed.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is,
1. An electric igniter or primer of the character described having the insulated
conducting wires and a bridge, the latter covered and supported by a suitable indam-
mable or explosive compound which is enclosed in a covering material of the character
described, and adapted to enter a detonator.
2. An electrical igniter having the bridge covered with a suitable inflammable or
explosive material which is enclosed in the manner described and a delay-action match
of the character described for use with an explosive detonator.

page_text: 3. An electrical igniter having the bridge surrounded and supported by the igniting
eliarge enclosed in a block of a shape to fit a detonator, and covered with a water-
proofing composition.
4. The igniter described having the wires and bridge and igniting charge covered
with a waterproofing material which is enclosed in a block of a shape to fit a detonator
and said block covered with a varnish, or other suitable waterproofing material, substan-
tially as described.
5. The combination with the igniter of the character described of the delay-action
match and the detonator, all adapted for connection together in substantially the
manner hereinabove set forth.
6. The mode of combining upon a single electrical circuit, a series of delay-action
primers with one or more quick acting primers, so that although all the aforesaid
primers are simultaneously ignited by electricity, the explosion of the charges and
the consequent shattering effect takes place at different or varying periods of time
according to the will of the operator and the length of delay of the delay primers
substantially as described.
Dated this 27th day of September 1889
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.