Year: 1888

page_text: Date of Application, 23rd Feb., 1888
Complete Specification Left, 25th Oct., 1888
Complete Specification Accepted, 30th Nov., 1888
I, DAVID MEFFORD MEFFORD of Toledo Ohio in the United States of America
Gentleman do hereby declare the nature of this invention to be as follows :—
It has been proposed to use compressed air for the propulsion of artillery projectiles;
but the compressed air for this purpose being retained in a reservoir of limited
capacity, its pressure after several discharges becomes so far reduced that the
compressing apparatus must be employed to restore the necessary pressure.
My invention relates to a method of and apparatus for propelling artillery projectiles
by the combined use of compressed air and explosive, whereby I am enabled to give a
high velocity to the projectile and also to restore to a greater or less extent the pressure
in the reservoir. For this purpose, when the projectile is placed in the gun, I place
immediately behind it a case containing a charge of gunpowder or other explosive,
this case being provided with a friction firing tube having attached to it one end of a
lanyard that is fixed at its other end and is coiled loosely on a conical holder which
may be accommodated in a recess of the bore near the breech. On opening for an
instant a valve in the passage from the reservoir to the gun, the compressed air
admitted to the bore propels the projectile and the charge case, the lanyard uncoiling
itself as they advance along the bore. When they have attained a certain distance
from the breech, depending on the length of the lanyard, the strain on the lanyard
when it is quite uncoiled fires the friction tube and the charge in the case which
producing a large volume of gases behind the projectile not only accelerates the
projectile but also forces the compressed air back from the bore to the reservoir, the
valve being arranged to act as a check valve.
Instead of employing a separate case to hold the explosive charge, this
charge may be accommodated in a cavity provided for it in the base of the
projectile.
Detail this 22ml day of Kohrunry 1888
1
ABEL & IMRAY,
Agents for the Applicant.

page_text: An Improvement in the Method of and Apparatus for Discharging
Artillery Projectiles.
I, DAVID MEFFORD MEFFORD of Toledo, Ohio in the United States of America
Gentleman 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 :-
;
It has been proposed to use compressed air for the propulsion of artillery
projectiles but the compressed air for this purpose being retained in a reservoir
of limited capacity, its pressure after several discharges becomes so far reduced
that the conipressing apparatus must be employed to restore the necessary
pressure.
My invention relates to a method of and apparatus for propelling artillery
projectiles by the combined use of compressed air and explosive whereby
am enabled
to give a high velocity to the projectile and also to restore to a greater or less extent
the pressure in the reservoir. For this purpose, when the projectile is placed in the
gun, I place immediately behind it a case containing a charge of gunpowder or other
explosive, this case being provided with a friction firing tube having attached to it one
end of a lanyard that is fixed at its other end and is coiled loosely in a recess of the
bore near the breech. On opening for an instant a check valve in the passage from
the compressed air reservoir to the bore, the projectile and charge are propelled
pneumatically the lanyard uncoiling itself as they advance along the bore. When
they have attained a certain distance from the breech depending on the length of the
lanyard, the strain on the lanyard when it is quite uncoiled fires the friction fuse and
the explosive charge in the case which producing a large volume of gases behind the
projectile not only accelerates the projectile but also forces the compressed air back
from the bore to the reservoir.
Instead of employing a separate case to hold the explosive charge, this charge may
be accomodated in a cavity provided for it in the base of the projectile..
The accompanying drawing represents a sectional plan of the apparatus, which I
employ, which is shewn as if it were broken into parts, indicating that those parts may
be of any suitable or convenient length. The apparatus generally resembles
in construction a known form of pneumatic cannon or gun having on each side of its
barrel a tubular reservoir or magazine charged with coinpressed air.
A is the barrel, B B are the tubular reservoirs one on each side of the barrel
communicating freely with the space Cimmediately behind the breech.
The barrel has its hinder part I provided with trunnions T on which it can swing
opening the breech at the cylindrical joint J so as to give access for introducing the
charge through the breech. At this part the barrel is widened out to form a chamber
a little larger than the bore to accomodate a coil of lanyard L.
From the space C there is-a-passage the mouth of which forms a seating for a
valve V

page_text: The stem of this valve is extended backwards through a stuffing box and has fixed
on it a piston R which is fitted to work in a cylinder D. To this cylinder there is
from the space C a small passage governed by a stop cock E that can be opened by
band so as to adinit compressed air to act on the piston R. The stem of the valve V
extends beyond the piston R and terminates in a yoke Y engaging a cam lever F. The
projectile P which may be solid or hollow has behind it a case G containing gunpowder
or other suitable explosive and provided with a friction firing fuse to which is
attached one end of the lanyard L, the other end being fixed to the breech of the
barrel.
The reservoirs B B and C being charged with compressed air or other gas under
pressure the valve V being closed and the barrel A being swung on its trunnions T so
as to present its breech open, the projectile P and explosive case G are introduced into
the bore and also the coil of lanyard Land the barrel is then swung on its trunnions to
the position making good the joint J.
to
When the projectile has to be discharged the cock E is opened, if necessary,
subject the piston R to the pressure, and thereby to balance or nearly balance the
pressure on the valve V. By a quick stroke of the cam lever F the valve V is
opened for a moment and the pressure acting on the explosive case G propels
it and the projectile P so that they advance along the bore uncoiling the
lanyard L.
When they have advanced a distance determined by the length of the lanyard it
becomes strained and by pulling the fuse H fires the explosive in G.
The force of the explosion acting on the projectile P already in motion greatly
accelerates it, and at the same time the high pressure gases produced by the explosion
drive back from the bore a great part of the compressed air causing it to open and pass
the valve V and to return to the reservoirs, thus maintaining to a great extent the
pressure in the reservoir.
Instead of using a case G for containing the explosive separate from the
projectile, the explosive might be accomodated in a compartment of the projectile
itself.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to he performed I declare that what I
claim is :-
1. The herein described method of discharging a projectile by propelling it
pneumatically through part of the bore of a gun along with a charge of explosive,
and then automatically firing the said explosive, as and for the purposes set
forth.
2. In a pneumatic gun, the combination of the valve V its stem connecting it to the
piston R the cylinder 1) with cock or valve E, the yoke Y and cam lever F, arranged
and operating substantially as described.
3. For use in a pneumatic gun, in combination with the projectile P a charge
of explosive G with friction fuse H, and the lanyard L substantially as
described.
ABEL & IMRAY,
Agents for the Applicant.