IMPROVEMENTS IN APPARATUS FOR DISCHARGING ORDNANCE
Year: 1868

page_text: LETTERS PATENT to Josiah Vavasseur, of the London Ordnance
Works, Bear Lane, Southwark, for the Invention of "IMPROVEMENTS
وو
PROVISIONAL SPECIFICATION left by the said Josiah Vavasseur at
the Office of the Commissioners of Patents, with his Petition, on
the 2nd November 1868.
I, JOSLAH VAVASSEUR, of the London Ordnance Works, Bear Lane,
Southwark, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN APPARATUS FOR DISCHARGING ORDNANCE," to be as
follows:-
This Invention has for its object improvements in apparatus for 'dis-
charging ordnance. When a piece of ordnance is discharged by means of
a vent, which is left open during the explosion, flame and gases'resulting
from the explosion rush from the bore of the gun into the vent passage,
the vent thus becomes enlarged and the bore of the gun close to where
the vent enters becomes starred or cracked, and the gun often ultimately..

page_text: becomes unserviceable from this cause alone. To avoid this injury to
the vent passage I provide for the firing of the charge whilst the vent is
closed in the following manner, which is also advantageous because it
causes à large volume of flame to be instantaneously thrown amongst
the charge to be ignited---I introduce into the outer end of the vent,
which is suitably chambered to receive it, a capsule like the case of a
cartridge for a breech-loading rifle. This capsule is provided with a per-
cussion priming and is loaded with à charge of gunpowder or similar
explosive material sufficient to produce the volume of flame required.
The capsule is held in the chamber of the vent so that it may not blow
back on firing by means of a suitable cover to the vent strong enough to
resist the pressure of the gas. This cover is also fitted with a needle or
striker for exploding the priming of the capsule. I prefer to arrange
the cover to slide from one side ou to the head of the vent piece so as to
allow the capsule to be withdrawn. This cover may be dovetailed so as
to hold it securely. When the cover is in its place the needle or striker
which it carries stands truly over the priming of the cartridge, and the
piece is fired by liberating a spring hammer which may also be mounted
on the cover so as to allow it to descend on the needle or stinker. The
liberation of the hammer may conveniently be effected by drawing out
a pin or stop by means of a lanyard or cord. On the discharge taking
place the pressure of the gas inside the capsule hermetically closes the
vent just in the same way as the breech of an ordinary military rifle is
closed gas-tight by the cartridge case against the gases produced by the
explosion. An extractor is provided in connection with the chamber of
the vent to eject the capsule.after firing.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Josiah Vavasseur in the Great Seal Patent Office
on the 30th April 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSIAH 30
VAVASSEUR, of the London Ordnance Works, Bear Lane, Southwark,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria; by Her Letters
Patent, bearing date the Second day of November, in the year of our
Lord One thousand eight hundred and sixty-eight, in the thirty-second 3

page_text: year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Josiah Vavasseur, Her special licence that I,
the said Josiah Vavasseur, my executors, administrators, and assigns, or
such others as I, the said Josiah Vavasseur, my executors, adminis-
trators, and assigns, should at any time agree with, and no others, from
time to time and at all times thereafter during the term therein
expressed, should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN APPARATUS
FOR DISCHARGING ORDNANCE," upon the condition (amongst others) that
I, the said Josiah Vavasseur, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and
scals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Scal Patent Office within
six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that I, the said Josiah Vavasseur, do hereby declare
the nature of the said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by
the following. statement thereof, that is to say:
This Invention has for its object improvements in apparatus for dis-
charging ordnance. When a piece of ordnance is discharged by micans
of a vent which is left open during the explosion, flame and gases
resulting from the explosion rush from the bore of the gun into the
vent passage, the vent thus becomes enlarged and the bore of the gun
close to where the vent enters becomes starred or cracked, and the gun
often ultimately becomes unserviceable from this cause alone. • To avoid
this injury to the vent passage I provide for the firing of the charge.
whilst the vent is closed in the following manner, which is also advan-
tageous because it causes a large volume of flame to be instantaneously.
thrown amongst the charge to be ignited:-1 introduce into the outer end
of the vent, which is suitably chambered to receive it, a capsule like the
case of a cartridge for a breech-loading rifle. This capsule is provided
with a percussion priming and is loaded with a charge of gunpowder
or similar explosive material sufficient to produce the volume of fling
required. The capsule is held in the chamber of the rent so that it
may not blow back on firing by means of a suitable cover to the vent

page_text: strong enough to resist the pressure of the gas, this cover is also fitted
with a needle or striker for exploding the priming of the capsule. The
cover slides from one sido on to the head of the vent piece so as to
allow the capsule to be withdrawn. This cover is dovetailed or made to
embrace the head of the vent piece so as to hold it securely. When
the cover is in its place the needle or striker which it carries stands
truly over the priming of the cartridge and the picoc is fired by a hammer
which may also be mounted on the cover. The hammer may conveniently
be actuated by the direct pull of a lanyard or cord. On the discharge
taking place the pressure of the gas inside the capsule hermetically
closes the vent, just in the same way as the breech of an ordinary military
rifle is closed gas-tight by the cartridge case against the gases produced
by the explosion. An extractor is provided in connection with the
chamber of the vent to eject the capsule after firing.
And in order that my said Invention may be most fully understood ]
and readily carried into effect, I will proceed to describe the Drawings
Figure 1 is a longitudinal section of the apparatus together with a
portion of the piece of ordnance to which it is fixed; the apparatus is 2
also shown in plan at Figures 2 and 3. In Figure 2 the vent is covered
and in Figure 3 it is exposed.
a is a veut piece, which is screwed as is shown into a passage formed
for it in the gun or piece of orduance; it has a head a¹ of a dovetail
form, in the centre of which is a cavity or chamber a² to receive a capsule. 2
This chamber is formed somewhat like the cartridge chamber at the
rear end of the barrel of a breech-loading rifle or fowling piece and it is
fitted with an extractor a³. The extractor is more clearly shown in
Figure 4, which is a transverse section of a part of the apparatus. The.
tail of the extractor is formed into a thumb piece, as is shown at
Figure 5. The chamber a³ receives a metallic capsule charged with
powder or other suitable explosive substance and provided at its base
with a percussion cap or similar fulminator. The capsule is shown at
Figure 6. 6 is a cover to secure the capsule in its chamber. This
cover is able to turn on the centre pin carried by an arm fixed to the 3
vent piece a and it fits to the dovetailed head of the vent piece. By
adapting the cover to the head of the vent piece in this way sufficient

page_text: rigidity is attained to withstand the great strain which comes on the
cover when the piece is fired. The cover is turned to one side, as is
shown in Figure 3, to uncover the chamber a for the introduction of
the capsule, and when the capsule has been inserted and the cover is
replaced the striker which the cover carries stands vertically over
the capsule, so that when forced down it strikes it at the centre of its
base where the fulminator is situate. The striker is a pin with a flange
upon it fitted into a cavity in a screw plug b' which the cover carries,
and it is there secured by cap b. A spiral spring holds the striker up
off the capsule until it is forced down by the hammer. Each time that
a capsule is inserted and the cover is brought over it the screw plug is
set down so as to bind the capsule in its place.
Figures 7 show the spanner which is used to work the screw plug.
The hammer c turns at c¹ on a pin carried by the cover b. A lanyard is
attached to the hammer c, and when it is desired to fire the piece by a
sudden pull on the lanyard the hammer is made to descend on the
striker and explode the capsule. is a stop screw fixed in the cover-b;
its end enters a groove in the vent piece a, so as to limit the motion of
the cover to the distance required. a' shows the extractor and the way
in which it is applied; it consists of a bent lever fitted in a recess in the
face of the head a' and turning on a centre. On one end of the lever
the flange of the capsule rests, the other is widened out to form a thumb
piece and is pushed down when the capsule is to be extracted; a spring
returns the extractor to its place. By the combination with the vent of
the cannon of an extracting instrument such as above described, the
capsule after firing is readily withdrawn from the vent, an operation
which otherwise would be difficult.
A capsule such as I prefer to employ is shewn to an enlarged scale at
Figure 6. The tubular part of the capsule I make of copper; it is
forced on to an iron disc or head containing a stout percussion
cap and having a projection on to which the cap is driven by the blow
of the striker. The tube of the capsule contains a small charge of
powder enclosed by a paper wad. The construction of the capsules
may be varied, and they may be made with the fulminating material
placed centrally or in the rim of the base, or the capsule may be made
with a pin to be struck by the hammer to explode the fulminating
material by a pin.
By the use of my Invention not only is the rapid wear of the vent

page_text: prevented, but the necessity of "serving the vent" or stopping with the
thumb during loading is avoided, and all chances of accident arising
from this operation being imperfectly performed are removed.
In applying my Invention to cast-iron guns it will not be necessary
to have a vent tube passing through the metal of the gun, the vent for
the greater part of its length may be simply drilled in the gun itself.
Having thus described the nature of the said Invention, and the
manner of performing the same, I would remark that I have discovered
that it has before been proposed to close the vent during firing, but
the arrangements which have been proposed have not been effectual
for the purpose; but what I claim is, the arranging apparatus for
discharging ordnance, combined and arranged substantially as herein
described.
I also claim the forming the vent cover dovetailed to embrace the
head of the vent piece, as herein described,
I also claim the combining with the vent of ordnance an extractor
such as that herein described to withdraw the capsule used in firing.
In witness whereof, I, the said Josiah Vavasseur, have hereunto
set my hand and seal, this Twenty-ninth day of April, in the
year of our Lord One thousand eight hundred and sixty-nine.