Improvements in Hand Electrical Firing Apparatus, applicable for Firing Ordnance, Grenades, Mining Charges, and the like.
Year: 1897

page_text: Date of Application, 11th Aug., 1897
Complete Specification Left, 4th May, 1898-Accepted, 18th June, 1898
Improvements in Hand Electrical Firing Apparatus, applicable for
Firing Ordnance, Grenades, Mining Charges, and the like.
I, CHARLES AMBROSE MCEVOY, of 69, Victoria Street, Westminster, in the
County of Middlesex, Engineer, do hereby declare the nature of this invention
to be as follows:-
-,
The electrical firing apparatus is composed of a cylindrical tubular casing which
can be held in one hand and which contains a dry battery cell. One end of the
tubular casing is closed by a disc of non-conducting material having two metal
stems extending out from it each carrying a binding screw; the other end is
closed by a metallic screw cap. The dry battery cell is of such a length as not to
completely fill the tubular casing but is held tight within it by a ring screwed
into the end of this tube and an interposed packing ring of wood. A cylindrical
stem can slide freely through the cap and is formed with a head on its outer end,
it is pressed outwards away from the battery cell by a coiled spring, a head on
the inner end of the stem limits the distance to which this stem or contact pin
can be thrust outwards. A forked safety key may be provided to prevent pre-
mature or accidental movement of the head.
One terminal wire of the battery which passes out from the inner end of the
battery cell is bent round to form a spring coil which when the battery cell is in
its place within the outer cylindrical casing bears against a metallic disc on the
central portion of the inner face of the non conducting disc which forms one end
of this casing. One of the metal stems which extend outwards from the non-
conducting disc is kept in electrical connection with the metallic disc by a metallic
spring contained in a recess in its inner end-one end of the spring bearing against
the disc and the other on the bottom of the recess.
The other terminal of the battery is led to a contact piece which is opposite to
the inner end of the stem or contact pin carried by the screw cap.
The contact pin is always in electrical connection with the metal of the outer
casing and so with the second binding or terminal screw which is also in metallic
connection with the casing. In this way whenever the head is pressed inwards
the end of the contact pin which it carries is brought against the contact on the
end of the battery cell and the battery circuit is thereby completed, through any
line passing from one terminal screw to the other.
The man using the apparatus holds the battery case with one hand with the
moveable head of this casing towards himself. To close the circuit he presses the
battery cell casing towards himself thereby forcing the head inwards and com-
pleting the battery circuit.
Dry battery cells and contact apparatus arranged as above described can be used
for firing the powder charges of ordnance, grenades, mining charges and such
like.

page_text: COMPLETE SPECIFICATION.
Improvements in Hand Electrical Firing Apparatus, applicable for
Firing Ordnance, Grenades, Mining Charges, and the like.
I, CHARLES AMBROSE MCEVOY, of 69, Victoria Street, Westminster, in the
County of Middlesex, Engineer, 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:
:
1 +
The electrical firing apparatus is composed as shewn in longitudinal section in
Figure 1 of the drawings annexed of a cylindrical tubular casing A which can
be held in one hand and which contains a dry battery cell B. One end of the
tubular casing is closed by a disc C of non-conducting material having two metal
stems DD extending out from it each carrying a binding screw; the other end
is closed by a metallic screw cap E. The dry battery cell is of such a length as
not to completely fill the tubular casing but is held tight within it by a ring F
screwed into the end of this tube and an interposed packing ring G of wood. A
cylindrical stem H can slide freely through the cap E and is formed with a
head on its outer end, it is pressed outwards away from the battery cell by a
coiled spring I, a head H2 on the inner end of the stem limits the distance to which
this stem or contact pin H can be thrust outwards. A forked safety key such as
shewn at Figures 2 may be inserted between the head H¹ and the screw cap: E to.
prevent premature or accidental movement of the head.
One terminal wire of the battery which passes out from the inner end of the
battery cell is bent round to form a spring coil J which when the battery cell is
in its place within the outer cylindrical casing bears against a metallic disc Kon
the central portion of the inner face of the non conducting disc C which forms one
end of this casing. One of the metal stems D which extend outwards from the
non-conducting disc is kept in electrical connection with the metallic disc K by a
metallic spring L contained in a recess in its inner end--one end of the spring bear-
ing against the disc and the other on the bottom of the recess.
The spring
may conveniently be either a coiled spring as shewn in Figure 1 or a bent spring
such as shewn in Figure 3.
The other terminal of the battery is led to or carries a contact piece M which is
opposite to the inner end of the stem or contact pin H carried by the screw cap E.
The contact pin is always in electrical connection with the metal of the outer
casing A. and so with the second binding or terminal screw D which is also in
metallic connection with the casing through a metallic strip N. In this way
whenever the head is pressed inwards the end of the contact pin H which it carries
is brought against the contact M on the end of the battery cell and the battery
circuit is thereby completed, through any line passing from one terminal screw
to the other.
The man using the apparatus holds the battery case with one hand with the
moveable head of this casing towards himself. To close the circuit he presses the
battery cell casing towards himself thereby forcing the head inwards and com-
pleting the battery circuit.
Dry battery cells and contact apparatus arranged as above described can be
used for firing the powder charges of ordnance, grenades, mining charges and such
like.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
1. In electrical firing apparatus the combination of an outer cylindrical case A

page_text: closed at one end by a non-conducting disc carrying two terminal pieces D and at
the other by a cap E-a dry battery cell held down within the casing so that one
pole of the battery is always in electrical connection with one terminal piece D-
a metallic connection between the other terminal piece D and the outer casing A
and a contact pin H carried by the cap E and normally held by a spring out of
contact with the other pole of the battery but which can be brought against it
by pressing the contact pin inwards.
2. Electrical firing apparatus constructed substantially as herein before
described and illustrated in drawing annexed.