Year: 1887

page_text: Date of Application, 10th Jan., 1887
Complete Left, 29th Oct., 1887
Complete Accepted, 29th Nov., 1887
100
I, HENRY EDWARD NEWTON of the Office for Patents 6 Bream's Buildings,
Chancery Lane in the County of Middlesex, Civil Engineer do hereby declare the
nature of this invention to be as follows:-
It is a well known fact that comparatively slight windage in guns very materially
reduces the explosive pressure exercised by a given gunpowder charge. Bearing in
mind that that part of a gun wherein the pressure tends to exceed a safe limit
represents but a small part of the entire length of the bore it is evident that if windago
sufficient to lower adequately the excess of pressure could be brought on and cut off
when needed the dangerous extra pressure would be got rid of whilst the waste of
powder gas on account of its short duration would be comparatively small.
Starting from these premises my communicant has devised a safety valve for cannon
which he thus describes.-
The gun is provided with one or more holes, leading from the powder chamber to
the face of the cannon on which is placed a kind of sliding valve which when moved
will open and shut the aforesaid outlet boles. Said sliding valve is connected with a
piston fitting into a small cylinder fixed to the cannon and communicating with its
powder chamber by means of a small hole through which when the charge is fired
powder gas enters into the aforesaid cylinder, pushes forward its piston which in its
turn moves the aforesaid sliding valve and causes it to open and shut the above
mentioned outlet holes in such manner that a discharge of gas from the cannon into
the atmosphere mainly takes place during the extremely short time when the explosive
pressure in the gun tends to be excessive. As the danger zone in guns is well
defined and experimentally determined it is easy to regulate accordingly the motion
of said sliding valve. Besides I affix to the small cylinder here above referred to a
scrow ending with a cone placed over the inlet for the powder gas into the aforesaid
го

page_text: cylinder and permitting of partly shutting that inlet so as to reduce the gas supply and
thereby retard at will the motion of the sliding valve.
It being easy by means of "crusher" measurements to ascertain the influence of
the aforesaid valve in reducing the excessive pressure in the danger zone of cannon,
the size of the holes or craters needed as well as the right duration of their function
can be experimentally found for each calibre of gun and form of shot. There are
two ways of proceeding, viz., either to have part of the crater or craters open when
the charge is being fired, then increase its or their width until the middle of the
danger zone is reached at which point the shutting off should begin; or to have no
outlet when the charge is being fired and let the crater or craters open only at the
point where the danger zone begins, then increasing and reducing the outlet as before
stated.
Instead of a sliding valve as herein described a safety valve somewhat resembling
those used for boilers may be applied. Such a valve may consist of a strong steel
bar or spring fastened to the gun at one end and connected at the other with a small
plug or piston covering a hole which leads into the powder chamber of the cannon.
If the feathering of said steel bar or spring is calculated at say 12 millimeters under
the pressure of 3000 atmospheres and it is desirable that the valve should not let out
gas before the pressure attains 1500 atmospheres then the aforesaid plug or piston
should when not acted on by pressure, enter 6 millimeters into the hole over which it
is placed. The valve then operates as follows:-So long as the pressure does not
exceed 1500 atmospheres the small piston aforesaid moves inside the gun hole and lets
out almost no gas. Beyond that point it opens freely and lets out more and more
gas as the inside pressure rises.
Instead of a straight spring as above stated the gun may be encircled with a steel
ring cut through in one place so as to act as a spring and closing tightly over small
holes bored from the outside into the powder chamber.
When excessive pressure
opens the circular spring, gas escapes which at once brings the pressure down to the
desired level and the grip of the steel ring above mentioned, again tightens.
The construction of the pressure regulator for cannon may be much varied but as
far as I know no safety valve for cannon has ever been proposed or carried out and
it is therefore an improvement resting less on details than on a novel principle.
It may be stated that a sliding valve offers greater facility than a spring valve for
instantaneously throwing off large volumes of gas and would therefore appear to be
most conducive to safety.
Dated this 10th day of January 1887.
NEWTON & SON,
Agents for the Applicant.

page_text: I HENRY EDWARD NEWTON of the Office for Patents, 6 Bream's Buildings,
Chancery Lane in the County of Middlesex Civil Engineer, 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 is a fact well known to Artillerists that comparatively slight windage in guns
very materially reduces the explosive pressure exercised by a given gunpowder
charge.
Bearing in mind that the danger zone in guns, or that part of the bore wherein
the explosive pressure tends to overstrain the metal, is generally limited to a very
small portion of the entire length of the bore, it is now proposed to effect the lateral
discharge of that part of the powder gas which causes excessive pressure. The
mechanical arrangement for effecting the reduction of the excessive gas pressure
admits of great variation.
I will however confine myself to a description of two arrangements by which the
object of the invention may be satisfactorily secured.
In the accompanying drawing,
Fig. 1 shews in longitudinal section the breech end of a gun fitted with a gas escape
valve according to this invention.
A is the body of the gun, B the bore, and C a steel plug screwed into the top side
of the gun within the danger zone, and made flush with the outer and inner peripheries
of the gun. This plug C is drilled out in two diameters to receive a piston valve
which fits the bore 6. of smaller diameter.-The stem of the valve carries wings
(see the plan view Fig. 2, which shows the plug detached from the gun, and the
winged valve in its place).-These wings fit the larger bore of the plug, and act as
guides for the piston valve. At their lower end, these wings rest upon the shoulder
formed in the plug when the piston valve is depressed, as shown at Fig. 1, and the
spaces between them form channels for the exit of the excess of powder gas. The
stem of the valve projects beyond the plug C, and upon it bears a powerful spring D,
affixed to the gun by means of screws d. This spring serves to retain the valve c in
place, and to yield only when an excess of gas pressure within the gun occurs.
facilitate the escape of the gas, the wings are cut away at their lower end, leaving only
a surface sufficient to rest upon the shoulder formed in the plug C.
The above described regulator operates as follows:-
To
So long as the explosive pressure inside the bore of the gun does not exceed a
certain fixed limit, determined at the time of constructing the apparatus, and which
it may be desirable to vary for varying sizes of guns, the piston valve c remains
within the smaller bore of the plug. As soon, however, as such limit is exceeded, the

page_text: spring D will yield to the upward pressure put on the valve, allowing the piston to
rise out of the small bore, and open a passage for the powder gas, which violently
escapes up the plug C into the atmosphere. As soon as the pressure inside the gun
has again subsided to its safe limit, the spring D re-acts on the piston c, causing it
to close the opening for the escape of the gas. The steel spring D, it will be under-
stood, in accordance with well known engineering formulas, is made of such strength
that its deflection, under a given pressure, will yield only for the escape of gas when
exceeding the intended maximum; thus the efficiency of the gun will he in no respect
impaired, while the liability of its bursting will be removed.
Fig. 3 shows another arrangement, which possesses over the one above described
the advantage of effecting a more immediate escape of a large quantity of explosive
gas. In this arrangement, the operation of the valve is regulated by the motion of
the projectile.
This Figure represents the breech end of a gun in longitudinal section, the same
letters of reference for like parts being used as in Fig. 1. E is a steel block made fast
to the gun by bolts e.-This block covers two lateral openings made in the upper side
of the gun. In one of these openings the valve c is fitted. This opening is extended
vertically through the block E, with a slightly increased diameter, to present a shoulder
for the valve to rest upon. Crossing this extension of the opening b is a horizontal
passage e leading to a vertical opening in the block E, which forms a virtual
extension of an opening * drilled through the gun. The extension of bis screwed
to receive a plug F, which is coned at its lower end to fit a coned seat formed for
it below the level of the horizontal passage e-Mounted upon the block E, and
extending to a filling piece E¹ attached to the gun, is a pressure spring D, which
bears upon the top of the valve c, and serves to hold it down in the position of
Fig. 3.
I have said that the epening in which the valve plays, passes through, or is met by
a horizontal passage el. This passage connects the opening &* with the open air
when the screw plug F is raised from its scat, as shewn at Fig. 3. In the upper part
of the valve c (see the transverse section of the gun Fig. 4), a hole is drilled to form
a continuation of the horizontal passage e'. So long, therefore, as the valve remains
in its depressed position, its opening will be in coincidence with the divided
passage el.
This regulating apparatus acts as follows:-
As soon as the projectile with which the gun is charged begins to move, on the
firing of the piece, it will open the passage b, up which the powder gas will rusb,
and turning into the passage el, will escape with great violence into the atmosphere.
If the passage b* is placed so far breechward as to be open even before the projectile
begins to move, it still more effectually prevents dangerous or excessive pressure in
the gun, but on the other hand, the waste of powder gas is thereby increased.
As the projectile, in its onward motion, reaches that part of the bore where the
danger zone is passed, it opens the passage b to the powder gas, which, acting on the
piston c, will press it upward, and cause it to close the passage e¹, thereby preventing
all further escape of powder gas. The return of the valve c to its quiescent position
is effected by the spring D, which should not be so strong as to force down the valve,
and thereby re-open the passage el before the projectile has reached the muzzle of the
gun. The screw plug F serves the purpose of reducing, at will, the outflow of
powder gas through the passage e-By its adjustment, therefore, means is provided
for regulating, at will, the utmost strain to which it is intended to expose the metal
of the gun. The lower end of the valve c is hollowed out, as shewn at Fig. 4, to
permit of the powder gas expanding the metal, and pressing it tightly against the
sides of the hole b wherein it moves. This will effectually prevent any fouling and
hardening in the opening, as the valve c, in moving downwards under the pressure of
the spring D, will remove any fouling from the opening before it has hardened
therein.
Instead of the arrangement herein shown for preventing the sticking of the valve
by fouling, any suitable means of lubricating the same may be adopted.

page_text: An opening is made in the filling piece E' in line with the passage e¹, for the
purpose of facilitating the dispersion into the atmosphere of the escaping powder gas.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me by my
foreign correspondent, I declare that what I claim is :-
1. Reducing the excessive pressure of powder gas in guns by providing a safety
exit for such gas in the manner herein set forth.
2. The means above described for relieving guns of excessive internal pressure, and
controlling the emission of the powder gas.
Dated this 29th day of October 1887
NEWTON & SON,
Agents for the Applicant.