A Fortification Turret Mounting for Quick-firing Guns.
Year: 1889

page_text: Date of Application, 7th June, 1889
Complete Specification Left, 6th Mar., 1890-Accepted, 26th Apr., 1890
PROVISIONAL SPECIFICATION.
A Fortification Turret Mounting for Quick-firing Guns.
I, THORSTEN NORDENFELT, of 53 Parliament Street, in the City of Westminster,
Civil Engineer, do hereby declare the nature of this invention to be as follows:-
This turret is not intended to be lowered level with the ground in critical moments,
but always to be kept at the same height above the ground. The shape given
to the turret, and the mounting, renders it nevertheless safe against hits.
In order to give the turret as small a height above the ground as possible, the gun
is placed at the top of the turret, with the line of sight beneath the centre line of the
gun, close to the ground. In order to give the men, working the turret and the
gun, as much space as possible, the turret is made highest behind the gun at the
spot where the gunner usually stands when working.
The exterior of the turret, from the ground to the top, from front to back forms an
inclining plane, and in the event of a shell striking on this surface it does not
penetrate but ricochets. The shape of the turret immediately over the gun is half a
truncated elliptical cone, whose axis coincides with that of the gun. The truncated
end of the cone where the gun protrudes through the turret is very small but the
cone widens towards the top of the turret. In order to give the turret the utmost
strength coupled with lightness the turret is made thicker on the face facing the
enemy, consequently the interior and exterior circumferences of the turret are
eccentric. The turret has a much smaller diameter than those now in use, but
permits the use of longer guns, as the gun partly protrudes.
The turret rests on a number of rollers kept in position by rings. The rollers are
fixed in the rings by means of spindles, the ends of which furthest from the centre
of the turret rest against a circular flange, cast in one piece with the base ring on
which the rollers run. The base ring rests on brickwork forming the lower structure
of the turret, and enclosing a chamber of convenient dimensions. The base ring
and the upper part of the brickwork are protected by a massive armour ring placed
around it. This armour protects all delicate parts necessary for the working of the
turret and the gun.
Beneath the gun, and well secured to the movable turret, is a bracket carrying
the gun gearing. In order to make all the arrangements as simple as possible, no
traversing gear for the gun is provided, but the turret itself is rotated. This is done
by a worin and worm wheel. The bearings in which the worm is carried are on the
above mentioned bracket and they always retain the same position in relation to the
turret whose vertical axis coincides with that of the worn wheel. This axis is not
however fixed but it is so mounted that it can yield to shocks resulting from rough
treatment to which the turret may be exposed.
The worm wheel however is prevented from turning, its spindle being connected
with the foundation of the turret.
The bracket however is able to rotate around it. The spindle is connected
with the foundation of the turret by means of a double universal joint, which
allows the turret to be slightly displaced in any direction carrying the spindle
with it.
The elevation and depression of the gun are effected by means of a common
screw, the top end of which is connected to the cradle by a pin whilst its lower
end runs through a movable nut, enclosed in a sleeve, provided with trunnions,
the bearings of which are placed in the above mentioned bracket.
The cradle is carried by two side plates so arranged that the gun which usually
brotrudes by more than half its length, can be partly carried inside the turret. The
side plates are fixed to the bracket by two bolts, the longitudinal axes of which are
•

page_text: parallel with that of the cradle trunnions. By removing the lower one of these
bolts, the side plates can, to a certain extent, rotate around the top bolt, thereby
allowing the gun to be drawn back. This manner of fixing the side plates has
the special advantage of allowing the gun to be totally removed from the
turret without necessitating the removal of the bracket and parts connected
therewith.
Dated this 6th dore of Iun 1000
COMPLETE SPECIFICATION.
A Fortification Turret Mounting for Quick-firing Guns.
1, THORSTEN NORDENFELT, of 32 Victoria Street, in the City of Westminster, 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:
This invention has for its object a fortification turret mounting for quick
firing guns.
This turret mounting is shown by the drawings annexed.
Figure 1 is a section of the turret mounting, with the gun and mechanism in side
elevation.
Figure 2 is a section of the turret mounting with the gun and mechanism in rear.
elevation.
Figure 3 is a horizontal section on the line A. B. in Figure 1 with the gun and
mechanism in plan.
a is a massive turret of iron or steel. This turret is not intended to be lowered
level with the ground in critical moments, but always to be kept at the same
height above the ground. The shape given to the turret, and the mounting, renders
it nevertheless safe against hits.
In order to give the turret as small a height above the ground as possible, the
gun bis placed at the top of the turret, with the line of sight C C beneath the centre
Jine of the gun, close to the ground. In order to give the men, working the turret
and the gun, as much space as possible, the turret is made highest behind the gun at
the spot where the gunner usually stands when working.
The exterior of the turret, from the ground to the top, from front to back on
either side of the gun forms an inclining plane, and in the event of a shell striking
on this surface it does not penetrate but ricochets. The shape of the turret
immediately over the gun is half a truncated elliptical cone, whose axis coincides
with that of the gun. The truncated end of the cone where the gun protrudes
through the turret is very small but the cone widens towards the top of the
turret. In order to give the turret the utmost strength coupled with lightness the
turret is made thicker on the face facing the enemy, consequently the interior and
exterior circumferences of the turret are eccentric. The turret has a much smaller
diameter than those now in use, but permits the use of longer guns, as the gun
partly protrudes.
"
The turret rests on a number of rollers dd kept in position by rings ďď. The
rollers are fixed in the rings by means of spindles, the ends of which furthest from
the centre of the turret rest against a circular flange e' cast in one piece with the
baso ring e on which the rollers run. The base ring rests on brickwork ff
forming the lower structure of the turret, and enclosing a chamber of convenient
dimensions. The base ring and the upper part of the brickwork are protected by
a massive armour ring g placed around the former. This armour protects all delicate
parts necessary for the working of the turret and the gun.
Beneath the gun, and well secured to the movable turret, is a bracket / carrying
the turret gearing. In order to make all the arrangements as simple as possible,
no traversing gear for the gun is provided, but the turret itself is rotated. This is.

page_text: done by a worm i and worm wheel k. The bearings in which the worm is carried
are on the above mentioned bracket and they always retain the same position in
relation to the turret whose vertical axis coincides with that of the worm wheel.
This axis is mounted on the bracket so that it can yield to shocks resulting from
rough treatment to which the turret may be exposed, and if the turret be slightly
displaced it carries the worm wheel and worm with it.
The worm wheel however is prevented from turning, its spindle being connected
with the foundation of the turret. The bracket however is able to rotate around
the wheel. The spindle is connected with the foundation of the turret by means of
a double universal joint 1 1.
The elevation and depression of the gun are effected by means of a common
screw m, the top end of which is connected to the cradle n by a ball and socket whilst
its lower end runs through a nut, provided with trunnions, the bearings of which
are placed in the above mentioned bracket h.
The cradle is carried by trunnions n' n¹ which are screwed into it and project
into bearing recesses formed in the turret at the sides of the embrasure. o is an
aperture in the turret for the insertion of the gun; it is securely closed by
a cover.
The breech closing mechanism; the firing mechanism; the recoil mechanism and
the sights are of usual construction.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, 1 declare that what I
claim is :-
1. A fortification turret mounting of substantially the peculiar form described and
supported upon rollers beneath its edge.
2. A fortification turret mounting supported upon rollers beneath its edge and
turned by gear flexibly connected to the foundation.
3. A fortification turret mounting supported upon rollers beneath its edge and
carrying a worm and worm wheel by which it can be turned the worm wheel
being prevented from revolving by a flexible connection with the foundation.
4. A fortification turret mounting carrying the gun at the top of the turret the
embrasure being so formed and the gun being so fitted that the line of sight is beneath
the gun.
5. Fortification turret mountings substantially as described and shown in the
drawings.
Dated this 5th day of March 1890.