IMPROVEMENTS IN ELECTRIC CARTRIDGES
Year: 1885

page_text: COMPLETE SPECIFICATION.
I SAMUEL RUSSELL, of N° 122, Montague Street, in the City of Brooklyn,
United States of America, Physician do hereby declare the nature of my invention
for "IMPROVEMENTS IN ELECTRIC CARTRIDGES" and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement:-
This invention relatos to that class of cartridges, for guns or other fire arms,
which are fired by electricity. The cartridge is constructed with a small electric
conductor of high resistance, usually a fine platinum wire, arranged in contact with
the powder, which conductor, upon the passage through it of a sufficient electric
current, is heated to incandescence and ignites the powder. This invention consists
in certain improvements in the construction of the cartridge, as fully hereinafter
described.
ก
Figure 1 of the accompanying drawings is an enlarged longitudinal mid-section
of a cartridge for a shot-gun constructed according to my invention. Figure 2 is
a transverse section thereof cut along the line 2 - 2 in Figure 1. Figure 3 is a
longitudinal mid-section of a bullet-cartridge for a rifle.
The distinguishing feature of this cartridge is that the incandescing conductor is
connected to the forward end of a primer or post which projects into the cartridge-
shell, from the base thereof. This primer consists of a tubular insulating sheath,
with one metallic conductor inside of it, and another metallic conductor on its
outside. The outside conductor is in electrical contact with the metallic base of
the shell, and the inside conductor is insulated from the base by the sheath. The
incandescing conductor is joined at one end to the said inside conductor, and at its
other end to the said outside conductor.
Referring to the drawings, A is the cartridge-shell, and B is the electric primer
or post projecting into the powder space in the shell. The shell has a metallic
base a; b is the tubular insulating sheath; c is the inside conductor, which is in the
form of a metal-pin; and d is the outside conductor which is shown as made of a
slender strip of metal, preferably copper or brass. The incandescing conductor e
lies across the front end of the tube 6 and is joined at one end to the front end of
the pin c, and at its other end to the copper strip d. This conductor e is preferably
a short piece of fine platinum wire, but a carbon filament or any other high
resistance conductor may be used. The primer is supported by being closely fitted
into a tubular neck a¹ forming part of the metallic base a. Thus the strip d, being
confined between the sheath 6 and neck a¹ is brought into electrical contact with
this neck, and hence with the base a.

page_text: Figures 1 and 2 show a paper cartridge shell, with metallic base a and charged
with the usual shot f and wads g, g. Figure 3, shows a metallic shell and a leaden
bullet f¹.
It is preferable that the incandescing conductor e be arranged near the front of
the charge of powder, in order that the powder may be ignited at its front, and
burn backward, thus preventing the blowing out of any unignited powder. The
conductor e may lie close against the end of the sheath b, as best shown in Figure 3,
in which case it is supported by the sheath and is protected from injury during
the explosion, thus enabling the shell to be recharged and used several times
successively. Or, the incandescing conductor may be formed in a loose projecting
loop.
This improved cartridge is superior to electric cartridges as heretofore made by
reason of its simplicity and cheapness, its durability, and the ability to ignite the
front of the charge of powder. The incandescing conductor is very short and
small, and is so mounted as to avoid liability of displacement while charging the
shell.
The cartridge is fired by being placed in an electric gun adapted to it whereby
the base a and the rear end of the pin c are connected with opposite terminal
connections of an electric battery, the circuit of which is closed by pulling the
trigger. The current then passes through the base a, conducting strip d, incan-
descing conductor e, and pin b, tl creby heating the conductor e to a red or white
heat, and igniting the powder with which it is in contact. The best electric gun
for this purpose of which I am aware is the one embodied in my application for
patent No 14,008 dated 22nd October, 1884.
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. An electric cartridge consisting of the combination with the cartridge shell
having a metallic base of a metallic conductor extending from the centre of the
base forward into the powder space, and insulated from the base, another metallic
conductor in electrical connection with the base and also extending forward within
the shell, and an incandescing conductor having its opposite ends connected
respectively to the front ends of said metallic conductors, substantially as and to
the effect hereinbefore set forth.
2. An electric cartridge consisting of a shell having a metallic base, a tubular
insulating sheath projecting into said shell from the base, an inside conductor
extending through said sheath and insulated thereby from the base, an outside
conductor extending along the outside of said sheath and in electrical connection
with the base, and an incandescing conductor at the front end of said sheath with
its opposite ends connected respectively to the front ends of said inside and outside
conductors, all combined and adapted to operato substantially as hereinbefore set
forth.
n
"
J. C. MEWBURN,
169, Fleet Street, London,
Agent.