IMPROVED ELECTRICAL IGNITER FOR ORDNANCE
Year: 1885

page_text: I, CHARLES DENTON ABEL of N° 28 Southampton Buildings, Chancery Lane
in the County of Middlesex, Consulting Engineer and Patent Agent do bereby
declare the nature of my invention for "IMPROVED ELECTRICAL IGNITER FOR
ORDNANCE" and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement
1
This invention relates to an improved construction of igniter for firing ordnance
by means of an electric current, the construction of which will be understood on
reference to the accompanying drawing in which Figs 1 and 2 shew longitudinal
sections to an exaggerated scale of different modifications of the igniter, and Fig 3
shews a part of the breech apparatus of a gun to a smaller scale, with the igniter
inserted The outer brass casing D Fig 1 of this igniter which is cylindrical and
which has a hole through its hollowed end, has inserted into it a brass or copper
capsule E¹ fitting accurately into the casing and constituting the electrode capsule,
which contains the electrode head J provided with a paper covering and pressed
firmly into it For the purpose of firmly securing the insulating paper covering
on the latter it is provided with a circular groove which has, at the same time, the
purpose of securing the head in position by means of a bulge H in the capsule
fitting into it In addition, the electrode head is secured by means of its groove
to the conducting wire K passing through the holo of the casing, and which is also
insulated by means of a paper cover The extension M of the conducting wire
consists of a brass wire covered with india rubber the connection being made by
overlapping the two ends of the wire, soldering them together, and after winding
fine copper wire round the same, it is insulated by means of a paper covering
To the front of the electrode head, accurately in the centre thereof, the one end
of a very fine platinum wire is soldered, the other end of this wire being con-
nected in a similar manner to the inner face of the electrode capsule
space Z in front of the electrode head is filled with a firing composition con-
sisting of equal parts of chlorate of potash and sulphide of antimony, loosely filled
in and enclosed in front by means of a paper disc free from acid. Lastly, the
space P of the igniter casing is filled with a firing composition consisting of fine,
The

page_text: and above this a metal cap
of the same construction as
place of the platinum wire a
somewhat pulverised, gunpowder which is enclosed by means of a cardboard disc
Fig 2 shews a modification of this igniter, which is
that above described with the sole difference that in
graphite bridge R is employed consisting of a ring
in contact with the edge of the electrode head which is also rubbed with
graphite
The igniter is inserted by means of the wire H into the touch hole of the firing
mechanism A as shewn, at Fig 3, and having been enclosed therein by the cap B,
the conducting wire is connected directly with the one pole of the source of
electricity while the second pole of the latter is put in connection with the gun
On closing the circuit, the current goes from the one pole to the electrode head,
from this through the wire or graphite bridge which in consequence thereof is
rendered incandescent, to the electrode capsule and through the casing D and the
gun, back to the second pole of the source of electricity In consequence of the
incandescense of the bridge, the igniting and firing charges are ignited whereby
the electrode head together with the electrode capsule are forced firmly against
the end of the casing D thereby effecting a perfect gas-tight closure of the touch
hole
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 The use in combination with an electrical igniter, of a special electrode
capsule E substantially as herein described with reference to Figs 1 and 2 of the
drawings
.
2 The use in combination with an electrical igniter of the electrode head J
Fig 1 arranged and operating substantially as herein described
E 3 In combination with an electrical igniter, the annular graphite bridge R
formed by coating the periphery of the insulating paper covering of the electrode
head J with graphite