Improvements in Automatic Guns.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in Automatic Guns.
We, KYNOCH LIMITED, of Lion Works, Witton, in the County of Stafford, and
GEORGE HOOKHAM, of New Bartholomew Street, in the City of Birmingham,
Manufacturers, do hereby declare the nature of this invention to be as follows:
Our invention relates to automatic guns, and its object is to more effectively
cool the barrel of such guns without the use of water.
Our invention consists in a combination of heat radiating ribs or surfaces
attached to the barrel, and a mechanical air draught induced by each discharge
of the gun either using the impulse of the gases as they leave the muzzle to act
as a pump or ejector, or using the recoil of the gun to operate a pump or fan.
In carrying our invention into effect according to one method, we provide the
automatic gun with heat radiating ribs which may form circles round the gun
barrel, or helices, or the ribs may be parallel in direction to the gun barrel.
Whichever form of radiating rib be used, we enclose the ribs in a thin casing
and we carry this casing forward to or connected to the muzzle of the gun in such
a manner that the gases discharged at each shot from the muzzle of the gun act
as an ejector or air pump, and produce a powerful rush of air along the surfaces
of the heat radiating ribs. We provide suitable conical or other terminations
within which the gases produced by the explosion act to form an air pump, and
we provide a large area to enable great volumes of air to be dragged over the
cooling surfaces.
Instead of using a jet air pump of this kind, we may use the movement of
the gun produced by recoil or by reaction, to operate an air pump or fan, and
thus to discharge air over the radiating surfaces.
Our invention may be modified in other ways, provided we adhere to the com-
bination of heat radiating surfaces and forced draught for cooling the gun barrel.
Dated this 2nd March 1898
MARKS & CLERK.
18, Southampton Buildings, London, W.C., and
13, Temple Street, Birmingham, Agents.
Improvements in Automatic Guns.
We, KYNOCH LTD., of Lion Works, Witton, in the County of Stafford, and
GEORGE HOOKHAM, of New Bartholomew Street. in the City of Birmingham,
Manufacturers, do hereby declare the nature of this invention and in what
Price 71

page_text: manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:—
This invention relates to automatic guns, and its object is to more effectively
cool the barrel of such guns without the use of water.
The invention consists generally in a combination of heat radiating ribs or
surfaces attached to the barrel and a mechanical air draught induced by each dis-
charge of the gun and in any means employed to produce such mechanical air
draught where the impulse of the gases as they leave the muzzle at each dis-
charge acts as a pump or ejector.
The accompanying sheets of drawings illustrate various methods of carrying
the invention into effect.
Figure 1 is a longitudinal section through the front end of an automatic or
magazine gun illustrating the mechanism employed to produce the induced
draught.
Figure 2 is a similar longitudinal section with certain variations in the position
and shape of the cooling ribs.
Figure 3 is also a longitudinal section similar to Figure 1 with a third varia-
tion in the shape of the cooling ribs.
Figure 4 is a transverse section on the line Figure 3, showing the casing
only.
Figures 5 and 6 are part longitudinal sections through the improved device
illustrating further modifications in the arrangement of the cooling ribs.
Figures 7, 8, 9, and 10 are longitudinal sections of alternative forms of ejector
nozzles which may be employed.
Figure 11 is a part side elevation of one arrangement of the cooling ribs
applied to a .303 automatic or magazine gun.
Figure 12 is a transverse section on the line cd Figure 11.
rear end is spirally fluted or
such
as
a
These
In carrying the invention into effect as illustrated in Figure 1 of the drawings
the construction and operation is as follows;-The barrel A. of an automatic
magazine gun towards the rear end B is increased in diameter
shown, and this
manner that a large number of radiating ribs C
grooved in
are formed.
radiating ribs C are clearly shown in the tuansverse section Figures 4
and 12. The extreme rear of the barrel D is not fluted but passes or slides through
a bush carried with the ordinary mechanism of the magazine gun so that upon
discharge the travel of the barrel due to the recoil is allowed for. Attached to
any suitable portion of the ordinary gun mechanism, distinct from the barrel, is
a chambered piece, such as E and this chambered piece has screwed, rivetted or
otherwise fixed to it a long sleeve or casing F enclosing both the fluted and plain
portions of the gun barrel and terminating at the outer end in a removable
nozzle, such as G. The chamber E leads by suitable port or passages H to
atmosphere. When the machine gun is in use it is evident that as each dis-
charge takes place within the nozzle G, and that ports or openings H lead to
the containing casing F, an ejector or pumping action will be set up by the
sudden rush of the expanding gases into atmosphere so that strong air currents
will be induced to flow over the ribs of the barrel in the direction clearly shown
by arrows. It is further evident that the velocity and volume of this air current
will depend upon the shape and size of the containing nozzle within which the
gun discharges and the shape and size of the passages and radiating ribs of the
casing F and gun barrel B, and it is always preferred to so arrange the conical
nozzle or other terminations within which the gases produced by the explosion
act to form an air ejector of such an area that great volumes of air are dragged
over the cooling surfaces.
Figure 2 of the drawings illustrates a cooling arrangement of a somewhat
similar nature to that shown in Figure 1, the parts which are not modified 5
having like letters to that figure. The modification consists in providing the

page_text: exterior containing casing F with a series of transverse radiating rings I prefer-
ably formed integral with the said casing and approaching to within a short dis-
tance of the fluted portion B of the gun barrel A. By this arrangement the major
portion of the induced air current is formed to travel between the flutings of the
ribs C. The direction of flow is also indicated here by arrows.
Figures 3 and 4 of the drawings illustrate a cooling arrangement also of a
somewhat similar nature to that shown in Figure 1, the parts which are not modified
having like letters to that figure. The modification illustrated in these figures
consists in arranging the containing casing F with a number of longitudinal
radiating ribs both on the interior and exterior of the casing. The exterior ribs
are lettered K and the interior J and their shape and arrangement is clearly
shown in both the figures in question. The operation of this modification is pre-
cisely similar to those herein before described and therefore requires no further
description. Arrows again indicate the flow of the induced air current.
Figures 5 and 6 are partial views which illustrate further modifications of the
radiating ribs. In Figure 5 a spiral rib L is formed round the gun barrel A and
the interior surface of the casing F almost touches the said spiral so that the
air current induced by the nozzle would be forced to take a helical course round
the barrel. Figure 6 on the other hand shows rings M and N attached alter-
nately to the barrel A and the casing F so that the induced air current would take
a tortuous path alternately towards the casing and towards the barrel.
The different forms of nozzles illustrated in Figures 7, 8, 9, and 10 may be
employed as substitutes for the nozzle G when required. Figure 7 is a nozzle
of ordinary construction where the diameter is gradually decreased towards the
exit. In Figure 8 the diameter of the nozzle quickly decreases to about the
centre of its length and then rapidly expands again, straight line surfaces being
employed. In Figure 9 the nozzle is at its smallest diameter about the centre
of its length but the increases in size are less rapid and the lines are curved.
In Figure 10 the smallest diameter is nearly coincident with the mouth of the
gun barrel about a first third of the nozzle's length and a gradual increase
towards the orifice then takes place.
Figures 11 and 12 show full sized drawings of portion of the rear end B cf
a .303 magazine gun illustrating the special form of radiating rib and spiral
grooves which it is preferred to employ in all the modifications. The grooves (
practically amount to a great number of screw threads or helices of very large
pitch cut upon the increased diameter B of the gun barrel A.
It is to be clearly understood that any form of ejector nozzle may be applied
to the casing and also that any form of radiating rib may be attached to either
the casing or the gun barrel.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed we declare that what
we claim is;-
1. In automatic, machine, or other guns, providing a casing around the barrel
open to atmosphere at the rear or breech end and terminated at the front or
nozzle end by a ejector nozzle of any suitable shape, all as a means of utilizing
each or any discharge of the gun to cool the barrel by inducing our currents to
pass between the said barrel and casing.
2. In automatic, machine, or other guns, in which the barrel is arranged within
a casing as specified, providing the said barrel with radiating ribs of any shape
or construction combined with a straight casing or a casing also provided with
corresponding ribs of any shape or construction and all in such a manner that
the induced air is compelled to take a tortuous or deflected path and so increase
the desired cooling effect.
3. The improved cooling device for automatic, machine or other guns. substan-
tially as herein before described with reference to Figure 1, 11, and 12 of the
accompanying drawings

page_text: 4. The improved cooling device for automatic machine or other guns, substan-
tially as herein before described with reference to Figure 2 of the accompanying
drawings.
5. The improved cooling device for automatic, machine or other guns, substan-
tially as herein before described with reference to Figures 3 and 4 of the accom-
panying drawings.
Dated the 20th 1
MARKS & CLERK,
18, Southampton Buildings, London, W.C., and
13, Temple Street, Birmingham, Agents.