IMPROVEMENTS IN APPLIANCES FOR DISCHARGING ORDNANCE
Year: 1879

page_text: PROVISIONAL SPECIFICATION left by Josiah Vavasseur at the Office o
the Commissioners of Patents on the 12th April 1879.
JOSIAH VAVASSEUR, of the London Ordnance Works, Bear Lane, Southwark
Engineer. "IMPROVEMENTS IN APPLIANCES FOR DISCHARGING ORDNANCE."
This Invention has for its object an improved method of discharging ordnance,
so that the charge may be ignited at any desired point within its mass by means
of electricity, without any vent or firing orifice being required. This is effected in
the following manner:-I insert a plug of steel or other suitable metal, so that its
inner end may be at any suitable point in the chamber of the gun, but by
preference in the line of the axis. This plug may be made so as to be readily
removeable by being screwed in, the screw having either complete or interrupted
threads. Through the centre of the plug passes a rod of steel or other suitable
metal, having at its inner end, where it is in the chamber of the gun, a head of
larger size than the rod. The rod is supported in the centre of the plug by
bearings of ebonite or other suitable insulating material, the ebonite not extending
to the inner end of the plug. The outer end of the rod is fixed in an ebonite
collar, which can slide in a suitable bearing made in the plug. A spring bearing
against the inner face of the ebonite tends to force the collar and with it the rod
outwards from the gun, and thus keeps the enlarged head of the rod bearing
against the inner face of the plug. To the outer end of the rod is attached by a
screw or other suitable means the connecting wire from the electric battery or
machine by which the gun is fired. On the gun being loaded a metal plate fixed
in the cartridge (as hereafter described) bears against the head of the rod, but
before the gun can be fired the rod must be moved inwards, so as to break the
contact between the head of the rod and the plug (since while this contact remains
the current of electricity would be short circuited without firing the gun). This is
effected by means of a short lever having a forked end, which takes in a groove
turned in the ebonite collar, the opposite end of the lever being made with an eye
for attaching a lanyard, by pulling on which the rod will be forced into the gun,
and immediately the contact is broken between the head of the rod and the end of
the plug it is insulated from the gun by the ebonite bearings, and the head being
in contact with the metal plate of the cartridge a current from the battery will
pass through the rod, and ignite the cartridge in the manner hereafter described.
On the lanyard being released the spring and, also on the gun being fired, the
pressure of the gases will force the head of the rod back against the inner face of
the plug, and thus prevent entirely, or very nearly so, all escape; but should any
gas pass between the head of the rod and the end of the plug. before the rod is
forced back on its seat, it passes into an annular space between the end of the

page_text: ebonite and the inner end of the plug, thence by a transverse hole into a central
longitudinal hole made in the rod, and finally passes into the atmosphere at the
outer end of the rod. The action of the gases will also force the metal plate of the
cartridge back over the head of the plug, thus entirely protecting the joint from
the action of the gases and rendering any escape still less probable. I also employ
a steel or metal plug placed as previously described, but fitted in the following
manner At the inner end of this plug it is recessed for a certain depth, and has
at the bottom of the recess a piece of ebonite or other suitable insulating material,
in the centre of which is fitted a short pointed piece of copper or other suitable
metal, the pointed end extending out of the plug and for a short distance into the
bore. This piece is made of smaller size than the recess in the plug, the space
between the two being filled up with ebonite, glass, asbestos, papier maché, or
other material, not readily or not at all combustible, and at the same time a
sufficiently good insulator. Should it be found desirable to protect the insulating
material from the action of the flame and heat caused by the explosion of the
charge, I fit on this point a cap of copper or other suitable material that is a good
conductor, with a flange or rim of sufficient size that, when driven back by the
explosion of the charge it will cover the insulating material. The cap will be so
made that before the gun is fired no part of it will be in contact with the body of
the metal of which the gun is composed, so as to avoid having a short circuit, this
cap or cover would probably have to be renewed every round. To the rear end of
the pointed piece, I attach an electrical conducting wire and take the same through
the centre of plug, it being insulated from the metal thereof, and on the outside of
the gun terminates in a loop or any suitable way, so that. the connecting wire from
'one pole of an electrical machine or battery may be attached thereto.
On the gun
being loaded the metal plate in the cartridge (hereafter described) is in contact
with the point, and a current being transmitted from the battery or machine will
pass through the point and ignite the charge in the manner hereafter described.
In
In the case of breech loading guns I prefer to put the steel or metal plug as
before described in the centre of the wedge or breech block, so that the metal point
is in line with the axis of the bore, and no hole is made in the tube of the gun.
some cases I insert the metal point with the insulating material into the wedge or
breech block itself, without employing the separate plug or holder. In wedge guns
I bring the central insulated conductor out to the side of the wedge block for more
convenient attachment of the battery wire. In order that the current from the
electric machine or battery may ignite the charge, I attach to the bottom of the
cartridge or at the required point thereof that will come well in contact with the
sliding head or metal point, a plate of metal, copper, or zinc, by preference, and of
suitable form so as not to touch the metal of the gun, to which plate I attach by
soldering or other suitable means to give a good connection, a conducting wire, or
strip of metal, of copper, zinc, or other suitable material, either insulated or not, as
may be necessary, which passes to a fuze placed at any desired position in the
charge. The fuze may be of high or low tension, suitably primed to suit the
nature of the electrical machine or battery by which it is to be exploded. A second
conducting wire or strip of metal is attached to the other pole of the fuze, and is
taken to the outside of the cartridge and allowed to project sufficiently to insure
the end of the same being in contact with the side of the bore of the gun or with
the base of the projectile, the latter being in direct metallic contact with the gun.
The return current to the battery or electrical machine takes place through a
conductor attached to some convenient point on the outside of the gun by a screw
or other simple means.
....