Improvements in the Art of Blasting, and Means for Performing the same.
Year: 1895

page_text: Date of Application, 19th Feb., 1895-Accepted, 23rd Mar., 1895
CUM LELE DIECIFICATION.
Improvements in the Art of Blasting, and Means for Performing
the same.
I, HENRY JULIUS SMITH, of Pampton Lakes, County of Passaic, State of New
Jersey, United States of America, Manufacturer, 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 relates, primarily, to blasting operations wherein an electrical
current is employed to ignite the fuses for the explosion of the blasting-charges in
the rock or other material to be dislodged; but my invention is applicable to other
operations wherein electricity may be employed to ignite ignitable devices.
In the utilization of electricity for purposes of ignition, such as the ignition of fuses
in blasting, and in analogous operations, it has been the prevalent custom to employ
a portable appliance, such as the dynamo-magneto electric machines now in general
use, for the generation of the electric-current at such various places in the field of
operations as may be necessary and expedient for its effective application to an
electric-circuit in which the fuses are interposed; in which appliance or machine it is
usual to accomplish the generation of the current by a single impulse, or the move-
ment through a definite and predetermined interval, of the generator-actuating device
at the hands of the operator. Means have been provided whereby the generated
current, accumulated in the appliance or machine, when it has attained the requisite
volume and intensity, is passed to and traverses a single working-circuit containing
the fuses or other ignitable devices.
But, owing, in part, to the fact that the energy accumulated in the machine is
not instantly dissipated when the current is passed therefrom to and traverses said
single working-circuit, and, in part, to the conservation of such energy. by a con-
tinuance, in a degree, of the generation of the current subsequently to its passing
to the said circuit, the current will possess or maintain a potency which will endure
at least until the force imparted by the current to the ignitable devices is therein
exhausted.
One object of this invention is to utilize, for purposes of ignition in blasting and
analogous operations, this said enduring potency of the electric-current. To this
end, my invention includes the method of utilizing electricity for purposes of
ignition in the art of blasting, etc., which comprises passing an electric-current,
from a circuit in which it is generated and accumulated, over a circuit in which
ignitable devices are interposed; and subsequently, and before the potentiality
successively imparted by the said current to the ignitable devices in the several
circuits is therein respectively exhausted, passing the said current over an additional
independent circuit, or circuits, one or more, successively, in which are interposed
further ignitable devices.
In many cases in blasting operations, and particularly in the excavation of
headings or tunnels, it is desirable to dislodge several layers or portions of the rock
in succession; first breaking and throwing down that portion at the rock-surface
and following this dislodgement with the successive breaking and throwing down
of layers or portions which are progressively further distant from the surface, and
to accomplish this by a single operation of firing of the blast-holes.
My invention also comprises the method of blasting which consists in locating
blast-holes in the rock to be dislodged, at progressively increasing distances,
successively, from the surface or outward face of the rock-wall; constituting a

page_text: series of independent electric-circuits, extending, severally, from an electrical
generator to the blast-holes, respectively, with the fuses or other ignitable devices
of the blasting-charges in said several holes respectively interposed in said circuits;
and causing a single electric-current to traverse said several circuits, successively,
before the potentiality thereby successively imparted to the blasting-charges in
the said several circuits is therein respectively exhausted; whereby the charges
in the holes nearest the rock-surface may be initially fired, and the charges in
the holes, which are progressively further distant from said rock-surface, may be
consequently successively fired.
In the dynamo-machines which are generally employed to develop an electric-
current for the purpose stated, the developed current is accumulated in the
electro-magnets until a sufficient volume and intensity to effect the desired
purpose have been obtained. The current during its development passes over a
circuit which is divided through a portion of its length into two unequal parts,
the shorter of which comprises the magnet-coils and their intermediate connec-
tions and connections to the pole-posts of the machine, while the longer consists
in the line-wires leading from said posts to the blasts and in which the fuses
are interposed. The said shorter part of the circuit is commonly called the
"condensing-circuit," it being that in which, owing to its lesser resistance, the
current accumulates as it is developed; while the longer portion is denominated
the "working-circuit," or circuit of application, the resistance of which is the
greater; whereby, during the development of the current; only a minor portion
thereof traverses it. In heretofore utilizing the current accumulated in the said
condensing-circuit, the said circuit has been broken when the current has been
fully developed, which has obliged the said developed and accumulated current
to traverse the outside or working-circuit wherein it encounters the resistance in
each fuse of a platinum bridge which, by that resistance, is heated to redness,
or more, thus igniting the priming in each fuse and firing the blasts.
In the drawings
Figure 1 illustrates a means which may be employed in performing my invention,
the condensing-circuit in the machine being shown broken.
Figure 2 illustrates a modification of said machine; and
Figure 3 illustrates my invention as applied to an improved method of blasting,
as set forth.
In practicing my invention the electric-current may be, and preferably is, developed
by the well-known dynamo-magnetic machine now generally in use for generating
electricity in blasting-operations. Such machine comprises an electro-magnet, A,
between the cores of which is arranged the rotary armature, B, journalled by its
arbor, C, to rotate in brackets secured to opposite ends of the magnet-poles. Upon
one end of the armature-arbor is arranged a commutator, D, consisting of the usual
_semi-cylindrical plates suitably insulated from each other and the armature, and
each connected with one end of the wire with which the armature is wound, and
springs, D', bearing respectively on said plates and connected respectively with the
magnet-coil terminals. The opposite magnet-coil terminals are connected to screw-
posts, or poles, F, F1, respectively, and said posts are respectively connected by
wires, e, e¹, with a bridge, G, and spring-terminal H, the said bridge spanning the
upwardly extended end of said terminal which is in contact with the bridge, and
which contact is preserved by the tension of said terminal when in normal position.
The circuit thus formed by the magnet-coils, wires, e, e', and their described
terminals in contact, and which constitutes the "condensing-circuit," is thus kept
closed. During the development of the current by the rotation of the armature,
the current is traversing two circuits, or a main-circuit divided through a portion
of its length into two unequal parts, of which one, constituted by the wires m, m³,
running from the posts F, F, respectively, is an outside or working-circuit in which
fuses, n, are interposed; and through this outside circuit only a small portion of
the volume of the current passes during its development, as the resistance of this
longer circuit is the greater; while to the said condensing-circuit within the

page_text: machine the larger portion of the current passes and therein accumulates, as the
resistance of this shorter circuit is the lesser.
In this machine the armature-operating device consists in a reciprocatory rack-
bar, K, which meshes with a loose pinion, I, mounted on an end of the armature-
arbor and adapted, by means of the clutch, I', and spring, i, when rotated in one
lirection, to rotate the armature, but to rotate freely in the opposite direction
without moving the armature. The bar, K, is of such a length that when it
approximates the limit of its movement in the direction to rotate the armature, and
the armature has attained its maximum velocity, the end of the bar will impinge
upon the free extremity of the spring-terminal, H, which is for this purpose located
in the path of the movement of sail bar, and remove said terminal from contact
with said bridge, G. By this means the current accumulated in the condensing-
circuit is shifted therefrom to the working-circuit, m, m', and fires the fuses
therein.
The devices thus far described are not novel and I make no claim to them herein.
Nor do I confine myself in this present invention to the combination with the
further devices to be presently herein described, of the specific devices hereinbefore
set forth, as a means for performing my invention; inasmuch as any known or
equivalent appliance may be employed to generate and accumulate the electric-
current, and the armature may be operated by levers, segments or other devices
for producing intermittent or reciprocatory motion; while the shifting of the
accumulated current may be effected, from the condensing-circuit to the working-
circuit, by any positively-operated device, or switch, located in such relation to
the armature-operating device as to have mechanical connection established with,
and to be actuated by the movement of, the armature-operating device to rotate
the armature.
In carrying out a feature of my invention, I pass the current, subsequently to
its traverse of the working-circuit, m, m', to an additional independent circuit, or
circuits, successively, in which further ignitable devices are interposed, and before
the potentiality successively imparted by said current to the ignitable devices in
the several circuits is therein respectively exhausted.
At H', I show a terminal or anvil which is located relatively to the terminal, H,
so as to be struck by, and have electrical connection established with it by, the
said terminal, H, by a continuance of the movement of the bar, K, in the direction
to rotate the armature, after contact between the bridge-terminal, G, of the
condensing-circuit, and said terminal, H, has been broken by the flexure or
movement of the terminal, H, due to the impingement upon it of said bar, K.
The terminal, H', is electrically connected to a screw-post, or pole, F2, by a wire, e³,
and from said post extends a line-wire, m², which is united to wire, m', by wire, m³,
thus constituting an additional independent working-circuit, m², m³, m³, in which
fuses, n', are interposed.
At H2, I show a second spring terminal interposed between the terminal, H,
and the terminal, H', and suitably insulated, and located, relatively to said
terminal, H, so as to be struck by, and have electrical contact thereby established
with it by, said terminal, H, by the continued movement of the bar, K, in the
direction to rotate the armature, and relatively to the terminal, H³, so as to
subsequently strike and thereby establish electrical contact with said terminal, by
the flexure or movement of said terminal, H', together with that of terminal, H,
due to a further continued movement of said bar, K, in the direction to rotate the
armature. The said terminal, H³, is electrically connected to a screw-post, or
pole, F³, by a wire, e³, and from said post extends a line-wire, m³, which is united
to wires, m², m³, by a wire, m³, thus constituting a further additional independent.
working-circuit in which fuses, n³, are interposed.
It is evident that during the movement of the bar, K, in the direction to rotate
the armature, and preferably when the armature thereby approximates the
maximum of its velocity, mechanical connection will be made between said bar
and the terminal, H, thereby shifting the developed current from the circuit in

page_text: the machine, in which it has been generated and accumulated, to the first
described working-circuit in which are the fuses, n, which are thereby fired, and,
thereafter, establishing contact between the terminals, H and H2; or successively
establishing contact between terminals, H, H2, and H', so that the current may pass
successively from the condensing-circuit to said first working-circuit, firing the
fuses therein, and the second described working-circuit, firing the fuses, n',
tberein; or successively from the condensing-circuit to the several described
working-circuits, successively firing the fuses, n, n¹ and n², respectively interposed
therein.
And it is evident that the said several described terminals may be arranged
relatively to each other and to the armature-operating device, that so limited
though appreciable spaces of time will successively elapse between the passing
of the current from the condensing-circuit to the several described working-circuits,
that the current, the energy of which in the condensing-circuit, after it has been
initially passed to the first working-circuit, is conserved by a continuance of the
rotation of the armature, due to the continued movement of the bar, K, in the
direction to rotate said armature, in successively establishing the several described
terminal contacts, will successively pass to the several working-circuits before the
potentiality successively imparted by it to the fuses-respectively interposed in the
several circuits is therein respectively exhausted.
In practicing my improved method of blasting, as illustrated in Figure 3,
blast-holes, as shown at A, B, C, are located in the rock to be dislodged at
progressively increasing distances, successively, from the outward face, R, of the
rock-wall. These holes may be a succession of single ones, or, as illustrated,
a succession of series of holes.
The independent working-circuits, m, m³ ; m³, m³, m²; and m³, m³, m³, m², are
arranged to extend, respectively, from the described generator to the several holes,
or series of holes, A, B, C, as shown in Figure 3, with the fuses or other
ignitable devices of the blasting-charges in the holes, respectively interposed in said
circuits.
The single electric-current developed and accumulated in the dynamo-magneto
machine shown in Figure 3, and herein before fully described, is as herein before set
forth, successively passed over the said several working-circuits, whereupon the
charges in the hole, or holes, nearest the rock-surface will be initially fired,
and the outermost layer or portion of said rock will be first dislodged and thrown
down, and the charges in the holes successively progressively distant from the
rock-surface will be successively fired and the several layers of rock in which they
are located will be consequently successively dislodged and thrown down.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :
1. The method of utilizing electricity for purposes of ignition in blasting opera-
tions, etc., which consists in passing an electric-current, from a circuit in which it is
generated and accumulated, over a circuit in which ignitable devices are interposed,
and subsequently, and before the potentiality successively imparted by the said
current to the ignitable devices in the several circuits is therein respectively
exhausted, passing the said current over an additional independent circuit, or
circuits, successively, in which further ignitable devices are interposed; sub-
stantially as and for the purpose specified.
2. The improvement in the art of blasting which consists in locating blast-holes,
in the rock or other material to be dislodged, at progressively increasing distances,
sucessively, from the outward face of the rock-wall; constituting a series of
independent electric-circuits extending, severally, from an electrical-generator to
the blast-bules, respectively, with the fuses, or other ignitable devices of the
blasting-charges in the several holes respectively interposed in said circuits; and
causing a single electric-current to successively traverse said. several circuits before

page_text: the potentiality thereby successively imparted to the blasting-charges interposed in
the several circuits is therein respectively exhausted; whereby the blasting-charges
in the hole, or holes, nearest to the rock-face may be initially fired, and the
charges in the holes which are progressively further distant from the rock-face
may be successively fired, substantially as and for the purpose specified.
3. In a dynamo-magneto electric machine, the combination with the armature-
operating device and a switch located, relatively to said armature-operating device,
to have mechanical connection established with, and to be actuated by the movement
to rotate said armature of, said armature-operating device, and adapted to shift the
developed current from the circuit in the machine in which it is generated and
condensed to an outside or working-circuit, by said mechanical connection of said
device with said switch, of an additional switch, or switches, terminal or terminals,
one or more, adapted to successively shift the current from said first working-circuit
to an additional independent working-circuit, or circuits, one or more, and located
to have electrical contact successively established with the first said switch and with
each other by a continuance of the movement of said armature-operating device
in the direction to rotate said armature, substantially as and for the purpose
specified.
Dad thin 10th day of abruary 1805
ALLISON BROS.,
Agents for the Applicant.