Improvements in Barbette Gun Mountings.
Year: 1893

page_text: Date of Application, 24th Oct., 1893
Complete Specification Left, 21st July, 1894-Accepted, 25th Aug.,
1894
PROVISIONAL SPECIFICATION.
Improvements in Barbette Gun Mountings.
I, JOSIAH VAVASSEUR, of 8 Great George Street, Westminster in the County
of Middlesex, Engineer, do hereby declare the nature of this invention to be as
follows:-
In barbette gun mountings the gun is usually supported on trunnions situated on
a line passing across its centre of gravity. The gun is elevated or depressed by
raising or lowering its breech end therefore the breech has to be raised or lowered
considerably to give the requisite elevation and when the gun is elevated the
breech comes below the level of the top of the fixed protecting wall by which the
turntable which carries the gun is surrounded. Consequently sufficient space has to be
provided between the breech end of the gun and the protecting wall to allow of
the gun running back on recoil. If space also is allowed for loading the diameter
of the cylindrical armoured wall becomes considerably more especially when long
guns are used even though the trunnions of the gun are brought near to the wall
when the gun is run out into firing position.
The object of this invention is to allow of cylindrical armoured walls of smaller
diameter being used and yet to allow of the weights carried by the turntable being
balanced or approximately so on its opposite sides. To effect these objects in
place of having the trunnions of the gun crossing its centre of gravity I place
them near its breech end and support them on a carriage which runs on guides
that stand up from the turntable the fore part of the gun I support preferably
at its centre of gravity upon another carriage which runs on guides parallel with
the first and formed on a frame which can be raised or lowered for giving the
requisite elevation to the gun the frame works between guides which stand up
from the turntable in close proximity to the wall. The weight of the supports
and gun upon them I counterbalance or approximately so by a loading platform
carried upon the opposite side of the platform to that from which the gun projects.
The platform is protected by protecting walls and roof which extend outwards
beyond and above the outer protecting wall. An opening is made through the
front protecting wall of the loading platform for the gun to pass through-but as
this wall is situated only just in front of the trunnions by which the breech end of
the gun is supported the opening need be but little larger than the gun itself-just
sufficient space being left to allow the gun to run back at any elevation.
On one or other side of the gun an opening may be formed through the loading
platform through which ammunition can be handed up either by men on the turn-
table or otherwise.
The platform also may be made large enough for a reserve store of projectiles
to be carried upon it. In order also that the gun may be elevated just as readily
as when it is balanced about its trunnions I counterbalance the weight of the
rising and falling frame which supports the fore part of the gun and the weight
of the gun resting on it by chains or wire ropes passing over guide pulleys to a
counterbalance weight which can rise and fall between guides situated below the
centre of the turntable; or, in the case of large and heavy guns, hydraulic power
might be used for elevating the rising and falling frame or slide which supports
the fore part of the gun.
Preferably in order to diminish the size of this weight I use multiplying pulleys
in such a way that the balance weight rises and falls a greater distance than the
frame which supports the fore part of the gun.
The training gear may be at one side of the turntable below the outer fixed

page_text: protecting wall and be worked by men standing upon the turntable. The elevating
gear and the firer may also be on the same side of the turntable and the firer can
therefore communicate directly with the men who effect the training.
The front sight may be a fixed one carried from the turntable and the movable
back sight be carried upon the rising and falling frame by which the fore part of
the gun is supported.
COMPLETE SPECIFICATION.
Improvements in Barbette Gun Mountings.
I, JOSIAH VAVASSEUR, of 8 Great George Street, Westminster, in the County
of Middlesex, 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 :-
In barbette gun mountings the gun is usually supported on trunnions situated on
a line passing across its centre of gravity. The gun is elevated or depressed by
raising or lowering its breech and therefore the breech has to be raised or lowered
considerably to give the requisite elevation and when the gun is elevated the
breech comes below the level of the top of the fixed protecting wall. by which
the turntable which carries the gun is surrounded. Consequently sufficient space
has to be provided between the breech end of the gun and the protecting wall to
allow of the gun running back on recoil. If space also is allowed for loading the
diameter of the cylindrical armoured wall becomes considerably more especially
when long guns are used even though the trunnions of the gun are brought near to
the wall when the gun is run out into firing position.
The object of this invention is to allow of cylindrical armoured walls of smaller
diameter being used and yet to allow of the weights carried by the turntable
being balanced or approximately so on its opposite sides. To effect these objects
in place of having the trunnions of the gun crossing its centre of gravity I
place them near its breech end and support them on a carriage which runs on
guides that stand up from the turntable-the fore part of the gun 1 support
preferably at its centre of gravity upon another carriage which runs on guides
parallel with the first and formed on a frame which can be raised or lowered for
giving the requisite elevation to the gun-the frame works between guides which
stand up from the turntable in close proximity to the wall. The weight of the
supports and gun upon them I counterbalance or approximately so by a loading
platform carried upon the opposite side of the platform to that from which the
gun projects. The platform is protected by protecting walls and roof which extend
outwards beyond and above the outer protecting wall. An opening is made
through the front protecting wall of the loading platform for the gun to pass
through-but as this wall is situated only just in front of the trunnions by which
the breech end of the gun is supported the opening need be but little larger than
the gun itself just sufficient space being left to allow the gun to run back at any
elevation.
On one or other side of the gun an opening may be formed through the loading
-platform through which ammunition can be handed up either by men on the
turntable or otherwise.
The platform also may be made large enough for a reserve store of projectiles to
be carried upon it. In order also that the gun may be elevated just as readily as
when it is balanced about its trunnions I counterbalance the weight of the rising
and falling frame which supports the fore part of the gun and the weight of the
gun resting on it by chains or wire ropes passing over guide pulleys to a counter-
balance weight which can rise and fall between guides situated below the centre of

page_text: the turntable; or, in the case of large and heavy guns, hydraulic power
might be used for elevating the rising and falling frame or slide which supports
the fore part of the gun.
Preferably in order to diminish the size of this weight I use multiplying pulleys
in such a way that the balance weight rises and falls a greater distance than the
frame which supports the fore part of the gun.
The training gear may be at one side of the turntable below the outer fixed
protecting wall and be worked by men standing upon the turntable. The elevating
gear and the firer may also be on the same side of the turntable and the firer can
therefore communicate directly with the men who effect the training.
The front sight may be a fixed one carried from the turntable and the moveable
back sight be carried upon the rising and falling frame by which the fore part of
the gun is supported.
Figure 1 is a plan view and Figure 2 a vertical section of a barbette guu
mounting constructed according to my invention.
Figure 2 is a front elevation of carriage and slide.
Figure 3 is a part plan and Figure 4 a part vertical section of a modification
in which the gun is balanced by a balance weight acting through hydraulic
mechanism.
from
In Figures 1 and 2 A is the gun supported on trunnions B near its breech end,
the trunnions themselves being supported on a carriage C. The carriage rests on
inclined guideways on the top of two parallel upright frames D that stand пр
a turntable E. The turntable rests upon and is supported by a ring of rollers in
the ordinary manner.
A' is an arm extending downwards from the gun near its centre of gravity and
jointed at its lower end to a slide F which rests on inclined guides G formed on the
top of a slide G¹ which can be raised or lowered between vertical guides which
stand up from the turntable E.
H is a chain attached to the bottom of the slide G¹ passed over a guide pulley I
and secured to a pulley J.
A chain K secured at one end to a fixed point is led one, two or more times
around the pulley J and a second pulley L mounted upon the turntable in such a
position that the chain may hang down from it and be attached to a counter-
balance M that can rise and fall inside a vertical tubular guide N below the centre
of the turntable.
O is an armoured wall surrounding the turntable and the mounting upon it.
P is an outer or rear platform fixed to the uprights D and other uprights D¹ that
stand up from the turntable E. This platform extends over and beyond the wall O
and is surrounded by and connected to an armoured wall Q through which is an
opening Q of just sufficient width for the gun to pass through and covered by a
roof through which suitable provision may be made for ventilation. P' is an inner
platform to facilitate loading and working the gun. R are projectiles stored at the
rear of the outer platform P; S is an opening formed through the turntable
through which ammunition can be handed up and passed on to the inner plat-
form P by men standing on the turntable.
The training aud elevating gear may be of any ordinary description and be
worked by men standing on the turntable.
The front sight T is secured to an upright from the turntable at a level just
above the top of the wall O. The back sight U can be set higher or lower upon a
slide V which can move up and down in vertical guides and is geared with the
slide G' in such a way that when one is raised the other is lowered.
In the drawings the slide G' is shewn to be raised or lowered by the turning of
a hand wheel W geared by bevil pinions with a spindle W' on which is a worm W
gearing into a worm wheel W on the spindle of which is a pinion W₁ gearing into
a toothed rack G* on the slide G¹. The toothed rack G' also has gearing with it
a pinion X the spindle of which by bevil toothed gear gives notion to a spindle X'
on which is a pinion X³ gearing into a toothed rack X' on the slide V which

page_text: carries the moveable back sight. In this way the slide V is lowered when
slide G¹ is raised.
In the modification shewn at Figures 3 and 4 provision is made for storing
projectiles on the turntable E in rear of the gun-they may also be stored on the
outer platform as in Figures 1 and 2.
The counterbalance weight M is made to surround a vertical tube which
descends from the centre of the turntable and up through which ammunition may
be hoisted and delivered through an inclined-swivelling tube at the top to any
position desired to be handed up to the loading platform.
The carriage C which at its rear end supports the gun trunnions has fixed to its
front end two vertical cylinders Y Z open at the top and each fitted with a piston
and filled with liquid below these pistons. The piston of the cylinder Y is coupled
by a connecting rod Y' with the gun near its centre of gravity. The piston of the
cylinder Z is forced downwards by a chain H passing over a fixed bar H¹ round
the forward end of the carriage C and over pulleys H³ on the top of the piston as
the two ends pass from guide pulleys H to guide pulleys H supported on
the carriage C and from the guide pulleys H they pass over other guide
pulleys H supported on the turntable and then downwards and secured to
pulleys J which are drawn downwards by chains K passing around these pulleys,
one end of which chains are fixed below to side supports going down from
the turntable and at their other ends to the counterbalance weight M.
Z is a passage passing from the bottom of the cylinder Z to the bottom of the
cylinder Y. Z is a valve opening from the passage Z₁ into the cylinder Y.
Normally when there is the same pressure in the cylinders Y and Z this valve is
held open by a coiled spring Z by which it is surrounded so that liquid can pass
freely from one to the other. When the gun recoils the downward pressure on the
piston of the cylinder Y is increased causing the valve Z³ to at once close and
thereby preventing any alteration in the elevation given to the gun. The
downward pressure due to recoil may be diminished by placing the trunnions of the
gun below its axis. In place of the valve Z³ normally held open by a spring a
stop valve may be used as shewn at Figs. 5 and 6. In this case the stop valve
would be closed whenever the gun was about to be fired and opened whenever the
elevation of the gun is required to be altered.
The whole of the outer or rear platform is not shewn in Fig. 4; it may be the
same as in Figure 1.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what I
claim is :-
1. A gun supported near its rear end on trunnions and near its centre of gravity
upon a slide that can be raised or lowered and is acted on by a counterbalance
weight to approximately balance the weight of the gun.
2. The combination with a gun supported in the above way of hydraulic
mechanism for preventing the downward thrust of the gun from altering the
elevation at the time of recoil.
3. The combination of the turntable the gun supported upon it in the above
way, the armour wall surrounding the turntable and gun slide and the armour
protected loading platform projecting over the top of the armour wali in rear
of the gun.
4. The construction of barbette gun mountings substantially as bereinbefore
-described and illustrated at Figures 1 and 2.
5. The construction of barbette gun mountings substantially as herein before
described and illustrated at Figures 3 and 4.
J. VAVASSEUR.