Improvements in Apparatus for Firing Ordnance.
Year: 1892

page_text: Date of Application, 22nd Oct., 1892
Complete Specification Left, 10th July, 1893-Accepted, 12th Aug., 1893
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Firing Ordnance.
I, HENRY CAPEL LOFFT HOLDEN Captain Royal Artillery Royal Arsenal
Woolwich do hereby declare the nature of this invention to be as follows:-
In order to obtain the advantage of the simplicity of an open vent without the
disadvantage which is associated with its employment, namely the more or less
rapid erosion or wearing away of the metal in the interior of the said vent, due to
the mechanical and chemical action of the gas rushing through it, I employ an
arrangement which works on the following principles. When an ordinary gun is
fired the charge of explosive which it contains is converted more or less rapidly
into gas and exerts a pressure upon the base of the projectile, which latter tends
to move in virtue of this pressure exerted upon it at a velocity which is inversely
proportional to its weight; if the gun have an open vent by means of which it is
fired, then the tube used to fire it may be considered as a projectile also, and will
obey the known laws of motion in a similar manner.
If the weight of this tube per unit of area exposed to the pressure of the gases,
be the same as that of the projectile, then the space through which it has moved
in a given time will be the same as that of the projectile, but if the unit of weight
per unit of area be greater than that of the projectile then the space traversed
will be proportionately less, so that by suitable proportions of the area and weight
of the tube to that of the projectile, it is possible to arrange that the tube shall
move an altogether insignificant distance compared to the projectile whilst the
latter is passing down the bore of the gun; as soon as the projectile has left the
gun, the pressure in the bore is very rapidly reduced to that of the atmosphere,
and the tube therefore when this action has taken place moves on only with the
momentum it has previously acquired, and by the time that it leaves the vent, the
pressure in the gun has been so reduced that there is no scoring or erosion produced
in the vent by the rush of the gases through it.
In the attached drawings descriptive of my invention and in which Figs. 1
and 2 represent the complete arrangement on the gun, whilst Figs. 3 and 4 show
the tube used, A. Fig. 1. is a weight suitably proportioned to the size of the gun,
the area of the vent, and to the weight and characteristics of the powder charge
as well as to the weight of the projectile.
This weight is hinged on the bolt B Fig. 1 which is fastened to the gun G
Fig. 1 and which is capable of a small amount of vertical movement upwards in a
slot, so as to enable the block whose centre of gravity is over the tube T. Fig. 1. to
rise with the latter a short distance when the gun is fired, before it turns over on
its pivot the bolt B Fig. 1.
The tube used & shown in Figs. 3 and 4 is a vent sealing one and consists of a
strong metal body M containing in its upper part or head the friction bar F., the
friction composition C, the metal plug P and the gunpowder or other suitable
explosive E. On firing the tube the flash from the friction composition C passes
down the channel through the centre of M firing the powder E, which latter fires
the charge, the pressure thus produced drives the plug P upwards to the top of the
tube past the aperture at F and the gas is thereby prevented from escaping, until
the tube has left the vent.
The tube may also be constructed so as to be fired by electrical means or by
percussion in a similar manner to other gun tubes.
Dated this 20th day of October 1892.
H. C. L. HOLDEN,
Capt., R.A.

page_text: :
Improvements in Apparatus for Firing Ordnance.
HENRY CAPEL LOFFT HOLDEN Major, Royal Artillery Royal Arsenal
Woolwich 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 :-
In order to obtain the advantage of the simplicity of an open vent without the
disadvantage which is associated with its employment, namely, the more or less
rapid erosion or wearing away of the metal in the interior of the said vent due to
the mechanical and chemical action of the gas rushing through it, 1 employ an
arrangement which works on the following principle.
When an ordinary gun is fired the charge of explosive which it contains is
converted more or less rapidly into gas, and exerts a pressure upon the base of
the projectile which latter tends to move in virtue of this pressure exerted upon it
at a velocity which is inversely proportional to its weight; if the gun has an open
vent by means of which it is fired, then the tube used to fire it may be considered
as a projectile also and will obey the known laws of motion in a similar manner.
If the weight of this tube, per unit of area exposed to the pressure of the gases,
be the same as that of the projectile, then the space through which it has moved
in a given time will be the same as that of the projectile, but if the unit of weight
per unit of area be greater than that of the projectile then the space traversed
will be proportionately less, so that by suitable proportions of the area and weight
of the tube to that of the projectile, it is possible to arrange that the tube shall
move an altogether insignificant distance compared to the projectile, whilst the
latter is passing down the bore of the gun; as soon as the projectile has left the
gun the pressure in the bore is very rapidly reduced to that of the atmosphere,
and the tube therefore when this action has taken place moves on only with the
momentum it has previously acquired, and by the time that it leaves the vent, the
pressure in the gun has been so reduced that there is no scoring or erosion
produced in the vent by the rush of the gases through it.
In the drawings filed with my Provisional Specification descriptive of my
invention, and in which Figs. 1. and 2 represent the complete arrangement in the
gun, whilst Figs. 3. and 4. show the tube used, A. Fig. 1. is a weight suitably
proportioned to the size of the gun, the area of the vent, and to the weight and
characteristics of the powder charge, as well as to the weight of the projectile.
This weight is hinged on the bolt B. Fig. 1. which is fastened to the gun G. Fig. 1.
and which is capable of a small amount of vertical movement upwards in a slot,
so as to enable the block, whose centre of gravity is over the tube T. Fig. 1. to
rise with the latter a short distance when the gun is fired, before it turns over on
its pivot, the bolt B, Fig. 1.
The tube used is a vent scaling one and consists of a strong metal body M
containing in its upper part or head the friction bar. F the friction composition C
the metal plug P and the gunpowder or other explosive E; on firing the tube, the
flash from the friction composition C passes down the channel through the centre
of M firing the powder E., which latter fires the charge, the pressure thus,
produced drives the plug P upwards to the top of the tube past the aperture at F,
and the gas is thereby prevented from escaping, until the tube has left the, vent.
The tube may also be constructed so as to be fired by electrical means or by
percussion in a similar manner to other gun tubes, and a spring may in like inanner
be substituted for the weight A.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed :-I declare that what I
claim is :
Improvements in apparatus for firing ordnance, substantially as described,
whereby the advantage of the simplicity of an open vent is obtained without the
disadvantage of the erosion or wearing away of the same.
Dated this 8th day of July 1802
H. C. L. HOLDEN,
Major, R.A.