Year: 1887

page_text: 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:-
This invention has for its object an improved centre pivotted mounting for a rapid
firing gun.
.
The base plate which is nearly flat is provided with a central cylindrical pivot
around which is a track for a series of balls of hardened steel. These balls support a
centre piece of bronze forming a part of a turntable and adjustable by means of a
screw thread to insure that a due proportion of the weight shall be supported upon the
balls, whilst a comparatively light load is borne by wheels or rollers which are
provided at the periphery of the turn-table, and which revolve upon radial axes.
These wheels or rollers are conical on the face and they run upon a corresponding
track on the base plate. Clips are also provided upon the turn-iable and these
embrace a flange upon the edge of the base plate, so that there may be no risk
of the turn-table being displaced by the shock of the recoil. Upon the turn-
table, in front of the pivot, there is fixed, in an upright position, a straight
armour plate, preferably of an height not to interfere with the sighting of the
gun and the upper edge of this armour plate is cut away in the centre to form an
embrasure for the gun. The armour plate is supported in rear by another plate
of the full depth of the armour plate and bent to a U form the armour plate forms
a cross tie in front. This support also is firmly secured to the turn-table; it is
cut away in rear nearly to the bottom to give passage to the breech end of the
gun. On this U form support an arm is fixed terminating in a shoulder piece, by
pressure against which the gun mounting with the gun upon it can be turned to
train the gun to bear upon the object. Upon the turn-table and on either side of the
U form support, where they are protected by the armour plate, lockers are provided
in which about a dozen rounds of ammunition can be stored.
On the upper part of the U form. support; near-to the front, bearings are provided
to receive trunnions formed upon a ring or hoop which is part of a frame in which
D.

page_text: the
gun is able to slide to and fro, recoiling always in the line of fire. The gun is
preferably made without trunnions and is suitably guided in the frame so that its
direction is invariably maintained during recoil. This frame is continued beneath the
gun, and at its rear end it carries another ring which embraces the gun near its
hinder end. The rings may also be connected together at the top. The gun sights
are fixed upon these rings and not upon the gun
itself. In the part of this trunnion
frame extending from ring to ring beneath the gun a hydraulic control cylinder is
provided and also a spring which is compressed during the recoil of the gun and
afterwards brings the gun forward again.
The recoil cylinder moderates the recoil and also the return movement and for this
latter purpose a plug is provided at the end of the cylinder which enters a cavity in
the face of the piston or rod.
Beneath the gun at the breech end there is a lug, and to this lug the piston rod
of the piston working in the control cylinder is attached. It passes through a
gland in rear of the cylinder. Two other rods are attached to the same lug,
they project forward passing one on either side of the control cylinder to a cross-
head and against the back of this a base disc at the end of the spring previously
mentioned abuts. This spring, when the gun recoils, becomes compressed between
the cross-head and the fore part of the control cylinder, which serves as the
abutinent for the spring. The spring does not hear directly upon the control
cylinder but upon the flange of a core piece which occupies the interior of the
spring, and the base disc at the other end of the spring is connected with the
core piece by a screw stem upon which it can slide. The stem serves to apply
to the spring a suitable initial compression.
The arm, on which is the shoulder-piece, carries gear by which the gun can be
elevated, and also locking gear to restrain the training movement. The locking gear
consists of an inclined axis with a hand wheel upon it, and also a screw thread near its
lower end. The screw thread works in a corresponding screw socket attached to
the form support, and by turning the hand wheel, a shoe at the end of the
axis is jammed against the face of the base plate; so the turn-table is rendered
immovable.
The elevating gear consists of a horizontal axis with a hand wheel at its outer
end and connected by bevelled pinions with an axis, on which is a screw thread
working into a trunnion nut supported by an arm projecting from the side of the
hydraulic control cylinder.
For the further protection of the gunners and mechanism an outer shield is also
provided. It also is of a U form with the convex part forward.
In the upper
edge of this convex part is cut the embrasure through which the gun projects, and
this is of such dimensions as to admit of the gun being depressed as far as may be
considered necessary. The lower edge of this shield overlaps the edge of the base
plate and serves to protect it from injury. The ends of the straight armour plate on
the turn-table meet the shield on either side and are firmly fixed to it, and it is in this
way that the shield is carried. The shield extends up on either side as far as may be
deemed necessary for the protection of the gunners, and these side projections support
a pivotted shutter shield extending from side to side over the gun; it can he turned
down so that its edge meets the top of the armour plate, and when in this position it
is inclined at a considerable angle and projectiles striking it are deflected so that
this shutter shield serves very completely to shelter the men from light projectiles. It
is so mounted that found to be in the way it can be readily removed or turned in a
horizontal position so as not to interfere with the view in front of the gun.
Dated this 10th day of T 1007

page_text: 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 :-
This invention has for its object an improved centre pivotted mounting for a rapid
firing gun.
The base plate which is nearly flat is provided with a central cylindrical pivot around
which is a track for a series of balls of hardened steel. These balls support a centre
piece of bronze forming a part of a turntable and adjustable by means of a screw thread
to ensure that a due proportion of the weight shall be supported upon the balls, whilst
a comparatively light load is borne by wheels or rollers which are provided at the
periphery of the turntable and which revolve upon radial axes. These wheels or rollers
are conical on the face and they run upon a corresponding track on the base plate.
Clips are also provided upon the turntable and these embrace a flange upon the edge
of the base plate, so that there may be no risk of the turntable being displaced by the
shock of the recoil. Upon the turntable, in front of the pivot, there is fixed, in an
upright position, a straight armour plate, preferably of a height not to interfere with
the sighting of the gun and the upper edge of this armour plate is cut away in the
centre to form an embrasure for the gun. The armour plate is supported in rear by
another plate of the full depth of the armour plate and bent to a U form; the armour
plate forms a cross tie in front. This support also is firmly secured to the turntable;
it is cut away in rear nearly to the bottom to give passage to the breech end of the
gun. On this form support an arm is fixed terminating in a shoulder piece, by
pressure against which the gun mounting with the gun upon it can be turned to train
the gun to bear upon the object. Upon the turn-table and on either side of the U form
support, where they are protected by the armour plate, lockers are provided in which
about a dozen rounds of ammunition can be stored.
On the upper part of the U form support, near to the front, bearings are provided
to receive trunnions formed upon a ring or hoop which is part of a frame in which
the gun is able to slide to and fro, recoiling always in the line of fire. The gun is
preferably made without trunnions and is suitably guided in the frame so that its
direction is invariably maintained during recoil. This frame is continued beneath the
gun, and at its rear end it carries another ring which embraces the gun near its hinder
end. The rings may also be connected together at the top. The gun sights are fixed
upon these rings and not upon the gun itself. In the part of this trunnion frame
extending from ring to ring beneath the gun a hydraulic control cylinder is provided
and also a spring which is compressed during the recoil of the gun and afterwards
brings the gun forward again.
The recoil cylinder moderates the recoil and also the return movement and for this
latter purpose a plug is provided at the end of the cylinder which enters a cavity in
the face of the piston or rod.
Beneath the gun, at the breech end, there is a lug, and to this lug the piston rod of

page_text: the piston working in the control cylinder is attached. It passes through a gland in
rear of the cylinder. Two other rods are attached to the same lug, they project
forward passing one on either side of the control cylinder to a cross-head and against
the back of this a base disc at the end of the spring previously mentioned abuts. This
spring, when the gun recoils, becomes compressed between the cross-head and the fore
part of the control cylinder, which serves as the abutment for the spring. The spring
does not bear directly upon the control cylinder, but upon the flange of a core piece
which occupies the interior of the spring, and the base disc at the other end of the
spring is connected with the core piece by a screw stem upon which it can slide.
The stem serves to apply to the spring a suitable initial compression.
The arm, on which is the shoulder piece, carries gear by which the gun can be
elevated, and also locking gear to restrain the training movement. The locking gear
consists of an inclined axis with a hand wheel upon it, and. also a screw thread near
its lower end. The screw-thread works in a corresponding screw socket attached to
the U form support, and by turning the hand wheel, a shoe at the end of the axis is
jammed against the face of the base plate; so the turn-table is rendered immoveable.
The elevating gear consists of a horizontal axis with a hand wheel at its outer end
and connected by bevelled pinions with an axis, on which is a screw-thread working
into a trunnion nut supported by an arm projecting from the side of the hydraulic
control cylinder.
For the further protection of the gunners and mechanism an outer shield is also
provided. It also is of a Ụ form with the convex part forward. In the upper edge
of this convex part is cut the embrasure through which the gun projects, and this is
of such dimensions as to admit of the gun being depressed as far as may be considered
necessary. The lower edge of this shield overlaps the edge of the base plate and
serves to protect it from injury. The ends of the straight armour plate on the turn-
table meet the shield on either side and are firmly fixed to it, and it is in this way that
the shield is carried. The shield extends up on either side as far as may be deemed
necessary for the protection of the gunners, and these side projections support a
pivotted shutter shield extending from side to side over the gun; it can be turned
down so that its edge meets the top of the armour plate, and when in this position it
is inclined at a considerable angle and projectiles striking it are deflected; so that this
shutter shield serves very completely to shelter the men from light projectiles.
It is so mounted that if found to be in the way it can be readily removed or
turned in a horizontal position so as not to interfere with the view in front of
the gun.
In order that my said invention may be most fully understood and readily carried
into effect I will proceed to describe the drawings hereunto annexed.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a plan of a gun mounting constructed in accordance with my
invention.
Figure 2 is an elevation partly in section of the same.
Figure 3 is a rear elevation.
Figure 4 is a vertical section of a portion of the mechanism.
Figure 5 is a horizontal section taken on the line A A in Figure 4.
A is the base plate; it is firmly secured to a suitable foundation. It has at its
centre a pivot Al and around the pivot is a circular groove A² in which run balls
supporting the upper parts of the mechanism. The base plate has also a conical roller
track around it at A3 A3 and it is provided with a flange A to be embraced by clips
on the turn-table. B is the turn-table; it has an opening in the centre into which a
bronze block C is screwed. This block bears upon the balls D and at its under side
is grooved to receive the balls. The block C is adjusted by screwing it more or less
far into the central hole of the turn-table B, so that whilst the main portion of the
weight is taken on the block still the rollers at the periphery of the turn-table are not
lifted from the roller track A³. When the block Chas been suitably set it is fixed in
Invention.
Figure 2 is an elevation partly in section of the same.
Figure 3 is a rear elevation.
Figure 4 is a vertical section of a portion of the mechanism.
Figure 5 is a horizontal section taken on the line A A in Figure 4.
A is the base plate; it is firmly secured to a suitable foundation. It has at its
centre a pivot Ai and around the pivot is a circular groove A² in which run balls
supporting the upper parts of the mechanism. The base plate has also a conical roller
track around it at A3 A3 and it is provided with a flange A to be embraced by clips
on the turn-table. B is the turn-table; it has an opening in the centre into which a
bronze block C is screwed. This block bears upon the balls D and at its under side
is grooved to receive the balls. The block C is adjusted by screwing it more or less
far into the central hole of the turn-table B, so that whilst the main portion of the
weight is taken on the block still the rollers at the periphery of the turn-table are not
lifted from the roller track A³. When the block Chas been suitably set it is fixed in

page_text: position by locking pins. E are rollers at the periphery of the turn table; they are
received into recesses prepared for them and are carried upon radial pins or axes F F.
As represented in the drawings three rollers E one in front and two in rear are provided,
and these will be found sufficient.
The turn-table is provided with a transverse vertical flange B¹ to which an armour
plate or stout plate, which I shall term an armour plate, is attached; this plate is a
main element in the mounting. The turn-table B is also provided with a curved
flange B2 of horseshoe form to receive the U form support in rear of the armour plate.
B3 B are clips which engage with the flange A'. G is the armour plate; preferably
it is sufficiently thick not to be penetrated or injured by any of the lighter sort of
projectiles. The mounting so made is much less liable to injury and the gunners are
much better protected than if a lighter plate be employed.
The plate G is arranged vertically and extends transversely across the turn-table,
projecting on either side. At its bottom edge the plate G is firmly fixed to the
Hange B. His a U form support of iron or steel plate in rear of the armour plate G ;
it is rivetted all around its lower edge to the flange B2 on the turn-table. This Ụ form
support stands up high on the two sides where it has trunnion bearings H¹ H' fixed
to it, but in rear it is deeply cut away in order to allow of the gun being elevated to
a sufficient angle. This support H might be made in two separate pieces, one on either
side, but it is preferable to make it in a single piece, and I shall speak of it throughout
as if so made.
are
The trunnion bearings H'H' receive into them the trunnions I' of the frame I.
This frame is composed of two rings I I³ the front ring 12 having the trunnions.
These rings are connected beneath the gun by a hollow cylindrical casing I which is
cast with the rings, the rings can also be connected on the top. Within the part I'
the control mechanism is provided. The gun is without trunnions and is able to slide
freely to and fro in the rings 1213; it is prevented from turning by a longitudinal
groove on the top of the casing I into which a key or keys I fixed into the
received. L is the gun; it has at its rear end a lug L₁ to which the rod M of the
piston M is fixed. The piston rod passes through a gland 1 into a cylindrical
chamber 1 containing oil or other liquid. When the gun is forward the liquid fills
the entire capacity of the cylinder excepting that occupied by the piston and piston-
rod. Narrow passages are provided in any usual way, by which, when the gun recoils,
the liquid in the cylinder is able to pass from the rear to the front of the piston ;
and preferably the passage is controlled, so that as the recoil proceeds the area is
diminished.
I is a fixed plug in the cylinder I which, when the gun is forward, enters a
corresponding cavity in the end of the piston-rod M'; it serves, when the gun moves
forward, to bring it gradually to rest; the liquid in the cavity of the rod being able
to escape past the plug with difficulty and comparatively slowly. The liquid is forced
into the cavity during recoil through a transverse hole I on the pressure side of the
piston. L L are rods connected with the lug L' upon the gun and passing forward
to a cross-head L. Against this cross-head the disc N pressed forward by the coiled
spring O abuts. P is a hollow core piece occupying the interior of the coiled spring O;
it is flanged outwards at its rear end, and the spring bears upon the flange holding it
up to the end of the cylinder I. Q is a bolt passing through the disc N and screwing
into the end of the core piece P; this bolt Q thus confines the spring O but allows it
to be compressed as the gun recoils. R is a curved shield fixed to the two ends of
the armour plate G; it extends down nearly to the ground line so as to protect the
mechanism and gunners as efficiently as possible; it extends up on either side of
the gun, but in front it is kept low not to interfere with the sighting of the gun or the
view in front. The shield carries a light pivotted shield S which, at pleasure, can
be closed down until its lower edge rests upon the top of the armour plate G. The
gun mounting is then completely closed in at the front with the exception of the openings
which are indispensable to the sighting and working of the gun.
T is an arm terminating in a shoulder piece T¹; it is fixed to the support H on the
left side. By lateral pressure against this shoulder piece the training movement is

page_text: sight carried by the ring P.
Figures 6, 7, 8 and 9 show a gun of larger dimensions also mounted according to
my invention.
Figure 6 is a side elevation with the shield partly in section.
Figure 7 is a longitudinal section.
Figure 8 is a rear clevation, and
Figure 9 is a plan.
In this case the turn-table is not carried on a pivot but ou a ring of live rollers.
The main frame as in the preceding figures consists of a transverse armour plate G
with a support or supports H upon the turn-table in rear of the armour plate.
The trunnion frame and the control apparatus are as will be seen from the drawings
substantially as already described.
There is also in front as before a curved shield R fixed to the ends of the armour
plate G; the top shield is partly fixed and is partly movable traversing in guides.
The training, elevating and locking gear is differently arranged and although it is
represented by the drawings, no claim is made in relation to it."
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. The pivot mechanism, consisting of the base A with its pivot A¹, annular
groove A², roller track A³ and flange A*; the turntable B with its clips B³; the central
adjustable block C; the balls D and the rollers E, substantially as described.
2. The main frame consisting of the turn-table B: the transverse armour plate G
and the support H in rear of the armour plate and both firmly fixed to the armour
plate substantially as described.
3. The trunnion frame and control apparatus consisting of the rings I² I³ connected
by the part I beneath the gun; the cylinder 1 within the part 14, the piston M with
its rod M' fixed to a lug on the breech of the gun; and the spring O compressed
on recoil by the cross head L³ which is also connected with the lug on the gun
substantially as described.
4. The shield arrangements consisting of the armour plate.G and the curved shield R
carried upon the ends of the armour plate G and with or without the pivotted shield S
substantially as described.
.
5. The training, elevating and locking gear consisting of the arm T and shoulder
piece T'; the hand wheel U and axis U; the hand wheel V, screw W and trunnion
nut W substantially as described.
6. My improved centre pivotted mounting for a rapid firing gun substantially as
represented by the annexed drawings.
Dated this 19th day of October 1887
CARPMAEL & Co.,
Agents for the Applicant.