An Improved Mounting for a Quick-firing Gun.
Year: 1889

page_text: Date of Application, 24th Dec., 1889
Complete Specification Left, 24th Sept., 1890-Accepted, 1st Nov., 1890
PROVISIONAL SPECIFICATION.
An Improved Mounting for a Quick-firing Gun.
I, JOSIAH VAVASSEUR of the London Ordnance Works, Bear Lane, Southwark, in
the County of Surrey, Engineer, do hereby declare the nature of this invention to be
as follows:-
A
This invention has for its object an improved mounting for a quick-firing gun.
The mounting is carried upon a bed plate which is securely bolted to a deck.
central pin or pivot is fixed into the bed plate and around the pin or pivot there is a
roller track.
A ring of live rollers runs upon the roller track and supports the base or sole plate
of the mounting which has a roller track on its underside and the pivot pin passes
through it at the centre. There are clips upon the sole plate which prevent it from
rising from the bed plate. At a short distance in front of the pivot and at right
angles to the axis of the gun a flat upright armour plate is fired upon the sole plate
of the mounting. This armour plate is supported in rear by two parallel upright
brackets at right angles to it and these are also fixed to the sole plate. A cradle in
which the gun is carried lies between the brackets and is supported by them on
trunnions the bearings of which are inserted through the brackets. The gun is
carried as low down or near to the base plate as is possible consistently with the gun
being elevated to a considerable angle when necessary and with this object the
hydraulic and spring apparatus by which the recoil is controlled and the gun returned
to the firing position is carried upon the cradle above the gun in place of below it or
at the sides as is usual. This recoil apparatus consists of a cylindrical casing parallel
to the axis of the gun in which are coiled springs and within this casing at its hinder
end is the hydraulic control cylinder. A piston works in the cylinder and its rod
passes out from the cylinder rearward and is fixed to an arm projecting upwards from
the breech of the gun. The piston has a notch or water way cut through it and a bar
or rib of suitable form fixed within the cylinder passes through this notch partially
closing the water way and by its form suitably regulating the space left for the passage
of the water at every part of the stroke which the piston makes in the cylinder as the
gun recoils and immediately afterwards returns to the firing position. Two horizontal
rods also are attached to the arm projecting from the gun and these pass along the
cylindrical spring case one on either side of it to the front thereof where they are
attached to lugs upon a piston like plate working within the spring case and upon
which the springs bear. When the recoil takes place this plate is drawn back by the
gun and the springs are compressed. The springs at their rear ends rest upon a solid
abutment in front of the hydraulic cylinder. The piston rod is hollow and a spindle
fixed at the fore end of the cylinder enters within it. The gun in moving forward
after recoil is controlled by the resistance which the spindle offers to the free escape of
liquid from the hollow in the rod.
The gun projects through an embrasure cut through the armour plate and the
sighting is done either over the top of the armour plate or through a notch in its
upper edge, the line of sight being high above the gun. The front and rear sights
are mounted together upon a sight bar, and this is fitted upon a curved arm upon the
cradle. The elevation is given to the sights by traversing the sight bar longitudinally
along the curved arm which for this purpose has a rack cut upon it. A worn upon a
small axis carried by the sight bar engages with the rack teeth and the worm is turned
by means of a milled head upon another axis which is geared by bevilled pinions with
the axis of the worm. The adjustment of the sights is performed by the aid of a scale
graduated upon the parts.
For the training of the gun and mounting a worm wheel is secured unon the centre

page_text: pin or pivot by a frictional connection or clutch and upon the sole plate of the
mounting there is an axis carrying a worm engaged with the worm wheel. This axis
is geared by bevilled gear with a vertical axis carried upon the bracket on the left
side of the gun and upon this vertical axis there is a hand wheel. This hand wheel is
conveniently placed for use by the man at the sighting station. The elevation is given
to the gun by means of a toothed arc fixed upon the cradle on the left side and near
its rear end. A pinion on an horizontal axis carried by the bracket gears with the
toothed arc and on the same axis and frictionally connected with it there is a worm
wheel. A worm on an axis carried by the bracket engages with the worm wheel and
by a hand wheel on the rear end of the axis the worm can be turned and so the
required movement may be given' to the cradle and gun. But the gun inay also be
elevated from the sighting station by the side of the gun where for this purpose
another hand wheel is provided; it is upon a vertical axis geared by bevilled pinions
with the axis of the elevating worm. The gun's crew and the mechanism are
protected by the armour plate and also by a cylindrical shield which, excepting an
opening in rear nearly surrounds the gun. The armour plate extends across the
cylindrical shield from side to side and the shield is fixed to its ends. There is an
embrasure in the cylindrical shield through which the muzzle of the gun projects.
The sighting platform upon which stands the man who controls the direction of the
gun is upon the left side of the gun; it is upon the sole plate of the mounting
immediately behind the armour plate and within the cylindrical shield. The
cylindrical shield is roofed over both in front and rear of the arinour plate by which
further protection is obtained. A sighting station and working gear may be provided
or both sides of the gun if desired.
In place of the central pivot, the mounting may be arranged to turn about a front
pivot but the centre pivot arrangement is usually preferable as it affords greater
protection to the gun's crew.
Dated this 24th day of December 1889
CARPMAEL & Co.,
Agents.
COMPLETE SPECIFICATION.
Au Improved Mounting for a Quick-firing Gun.
I, JOSIAH VAVASSEUR, of the London Ordnance Works, Bear Lane, Southwark in
the County of Surrey, 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 :-
The mounting is formed of a sole plate or turntable turning around a fixed central
pin or pivot and supported around its circumference upon a horizontal ring of rollers.
A flat upright armour plate rises up from the sole plate at right angles to the axis
of the gun and a short distance in front of the pin or pivot. The armour plate is
supported in rear by two parallel upright brackets which rise up from the sole plate.
A cradle in which the gun is carried lies between the brackets and the trunnions of
the cradle are supported in bearings which the brackets carry. The men working
the gun and the mechanism are protected by the armour plate and also by a cylindrical
shield which (excepting an opening in rear) nearly surrounds the gun. The armour
plate extends entirely across the cylindrical shield from side to side which is fixed to
its ends. Immediately in rear of the armour plate and between the upright brackets
which support the armour plate and the cylindrical shield is a sighting station at one
or both sides of the gun the platform on which the man stands in the sighting station
or stations is carried by the sole plate or turntable. The adjustment of the sight bar
and the training and elevating of the gun are done as hereinafter described by hand
wheels from this sighting station or stations.
The gun projects through an embrasure cut through the armour plate and also
through another cut through the front of the cylindrical shield.
The gun is carried as low down or near to the sole plate as is practicable con-

page_text: sistently with the gun being elevated to a considerable angle when necessary, and
with this object the hydraulic and spring apparatus by which the recoil is controlled
and the gun returned to firing position is carried upon the cradle above the gun in
place of below it or at the sides as is usual, The recoil apparatus consists of a
cylindrical casing parallel to the axis of the gun, the hydraulic cylinder occupies the
rear end of the casing, a piston works in the cylinder and its rod passes out rearwards
from the cylinder and is fixed to an arm that projects upwards from the gun. Within
the front of the casing are springs, these at their rear end bear against the front of
the bydraulic cylinder and at the front bear against a plate which by two horizontal
rods is connected to the arm which projects up from the rear end of the gun. The
passage of liquid from one end of the hydraulic cylinder to the other is controlled in
any ordinary manner.
3
The sighting is done through a vertical slot cut through the upper part of the'
armour plate so that the opening is high above the guu. The front and back sights
are both mounted upon a sight bar which is made to project outwards through the
slot so that the back sight may be within or in close proximity to the slot and a large
range of view obtained with but a comparatively narrow slot. The sight bar is
mounted upon the top of the cradle in such a manner that it can be inclined to it to
any desired extent. The roof over the portion of the cylindrical shield which is in
front of the armour plate is below the sighting opening so that the range of vision is
not obstructed by it.
In place of the central pivot the mounting may be arranged to turn about a front
pivot but the central pivot arrangement is usually preferable as it affords better
protection to the men working the gun.
In order that my invention may be fully understood and readily carried into effect I
will proceed to describe the drawings hereunto annexed.
.
3
DESCRIPTION OF THE DRAWINGS.
'
I
Figure 1 of the drawings annexed is a side elevation partly in section of the
mounting.
Figure 2 is a plan view of the same.
Figure 3 is a rear view,
Figure 4 is an elevation showing a modified way of carrying the sight bar.
Figure 5 in a plan view of the same.
Figure 6 is a longitudinal vertical section with parts omitted.
A is a bed plate which is securely bolted to any deck. A central pin or pivot
stands up from the bed plate and around it is a circular roller track on which rests a
ring of rollers B.
C is the sole plate or turntable resting on the rollers—the central
pin or pivot rises up through the centre of this sole plate. 'D D are clips which
prevent the sole plate rising from the bed plate. E is the armour plate which stands
up from the sole plate. F F are the two vertical brackets which support it at the
rear. G is the cylindrical shield surrounding the mounting except at the rear.
H is the gun and I the cradle in which it can slide end wise. are the trunnions of
the cradle; they turn in bearings I2 carried by the brackets. J is a cylindrical casing
formed on the top of the cradle above the gun. K is a hydraulic cylinder occupying
the rear end of this casing. K' is the piston rod extending rearwards and secured
to an arm H¹ which stands upwards from the rear end of the gun. L Lare coiled
springs within the front end of the casing J. L'is a support extending through the
centre of the coils of the springs and baving a central screw L² of which the head
bears against a plate L³ to give initial compression to the spring. L is a second
plate bearing against the front end or compression plate of the springs and having
side lugs from which two rods L extend rearwards and are secured to the arm H¹
which stands up from the gun.
When the recoil takes place the plate is drawn back by the gun and the springs are
compressed. After the recoil the gun is moved forward again as usual by the springs.
The running forward is preferably controlled as has before been done by a spindle

page_text: or ram fixed to the fore end of the hydraulic cylinder, passing into the piston rod
which is made hollow and offering resistance to the free escape of liquid from the
hollow of the piston rod.
To control the recoil the piston has preferably a notch cut from its circumference
and a rib fixed along the interior of the cylinder passes through the notch and by its
form regulates the size of opening left for liquid to pass from one end of the cylinder
to the other at every part of the stroke-this way of controlling the recoil is well
known. M is the sight bar carrying the front and rear sights-it is made to slide into
a dovetail groove formed along the top of a slide, M' which can be moved backwards
or forwards along a curved arm or projection M2, which stands up from the top of
the cradle and in this way the sight bar can be inclined to the cradle to any desired
extent. When not in use it can be drawn back along the dovetail groove in the
slide M¹ so as not to project through the sighting opening. When in use it is thrust
forwards until the rear sight comes within the opening. Movement can be given to
the slide M' by a curved toothed rack upon it gearing into a pinion M³ which can be
turned by a small hand wheel M ou its axis. N is the platform of the sighting
station on the left hand side of the gun-the man standing on this platform can not
only adjust and use the sights, but, also train and give the required elevation to
the gun.
i
.
The training is effected by turning the hand wheel O'and the elevation is given by
turning the hand wheel P. The axes of these wheels are carried in bearings by one
of the upright brackets F,
The hand wheel O is at the upper end of a vertical axis O' which at its lower end
gives motion by bevil wheels (2 to a horizontal axis O' which passes through the
bracket and on its inner end carries a worm O' that gears with a worm wheel Os fixed
as usual by a frictional connection or clutch to the central pin or pivot which stands
up from the bed plate A.
The hand wheel P gives motion by hevil wheels P¹ to an inclined axis Poo which
is a worm P³ that gears into a worm wheel P which by a friction clip Ps is held fast
to an axis Po on which is a pinion P7 that gears into a curved toothed rack which is
fixed to the gun cradle I.
The axis P also carries a hand wheel P8 on its rear end so that elevation can be
given to the gan either by turning the band wheel P or the hand wheel PB.
In place of the sights being carried by a bar that can be slidden backwards or
forwards along a curved arm as shown at Figure 1 the bar may be carried by a block
or tubular bearing that is jointed to an arm that stands out from the saddle and may
be set to any desired inclination by means of an arm extending rearwards from the
block as shown in Figures 4 and 5.
In these Figures M is the sight bar capable of being slidden backwards in a block
or tubular bearing jointed at Q to an arm M² which stands up from the cradle.
Qis an arm extending rearwards from the bearing Q and carrying at its end a small
pinion Q to gear into a curved toothed rack Q' fixed to the cradle or inner end of the
projecting arm M² so that by turning the pinion in one or other direction the sight
bar can be set at any desired inclination.
When carrying the sight bar in this way the back sight may conveniently he on
the bearing and the front sight only on the bar. When not in use the bar is
slidden back in the bearing Q so as to be out of the way or both sights may be on
the bar and the whole arranged to slide back for removal from the bearing. The
arm M² which stands up from the cradle can also be slidden backwards so that
when the sights on either side of the gun are not in use the sighting aperture
may be closed.
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 :-
... In combination with a turntable having an armour plate rising up from and
1111
in the sumans wlate at the

page_text: rear and a cylindrical shield extending around the gun except at the rear and a gun
cradle lying between the brackets with,its trunnions supported in bearings carried by
the brackets, a sighting station or stations at the side or sides of the gun within the
cylindrical shield and just in rear of the armour plate and training and elevating
mechanism worked by hand wheels from this sighting station or stations.
2. In combination with a turntable having an armour plate rising up from it in which
is a port hole through which the gun projects and with a gun carried within a cradle
turning on trunnions just in rear of the armour plate, a sight bar carried by the
cradle and projecting out through a separate sight opening formed through the
armour plate so that the back sight may be in close proximity to the sighting
opening.
3. The combination of the gun, the cradle in which it lies and spring and hydraulic
recoil and running out gear mounted on the top of the cradle instead of below it or at
the sides.
4. The combination of the gun, the cradle in which it lies and sights on a bar which
is carried on the top part of the cradle and is capable of being inclined to it to any
desired extent.
5. A gun mounting substantially as described and illustrated by the annexed
drawings.