IMPROVEMENTS IN MOUNT- ING ORDNANCE
Year: 1865

page_text: LETTERS PATENT to Robert Mallet, of 11, Bridge Street, in the City of
Westminster, Engineer, for the. Invention of "IMPROVEMENTS IN MOUNT-
ING ORDNANCE."
Sealed the 15th May 1866, and dated the 24th November 1865.
PROVISIONAL SPECIFICATION left by the said Robert Mallet at the
Office of the Commissioners of Patents, with his Petition, on the
24th November 1865.
I, ROBERT MALLET, of 11, Bridge Street, in the City of Westminster,
Engineer, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN MOUNTING ORDNANCE," to be as follows:-
This Invention relates to an improved mode of mounting what are known as
muzzle-swivelling ordnance, whereby the pointing of the gun is accomplished
by a simpler and more effective arrangement than those hitherto proposed for
that purpose. According to this Invention the pointing of the gun at any
angle in a vertical plane within the limits of its elevation or depression is
effected by two combined forces, the one tending to lift the gun bodily parallel
to itself, whilst the second force, acting in conjunction with the first, tends to
cause the gun to rotate round the axis of its trunnions. The effect of which
two combined motions simultaneously acting is to maintain the centre of
the actual muzzle of the gun constantly at the same level whatever may be
the angle of elevation or depression of the gun. Both these motions are

page_text: brought into play simultaneously by the force employed for raising or lowering
vertically or nearly vertically the trunnions of the gun; this may be accom-
plished either by the aid of hydraulic cylinders, elevating screws, or other
equivalent contrivances. One mode of practically carrying out my Invention
consists in mounting the trunnions of the gun in two metal blocks, which are
free to move up or down between guiding cheeks in each side of the carriage;
the inner faces of these cheeks being grooved to receive guiding. ribs or pro-
jections on the blocks, and thereby prevent any lateral displacement thereof.
These blocks are secured to the heads of the rams of two hydraulic cylinders,
which themselves rest upon trunnions fitting into seats at the bottom of the
opening left between the guiding cheeks in each side of the carriage, so as to
be easy of removal and replacement in case of fracture, or are otherwise fixed
to the gun carriage. The two hydraulic cylinders may be both supplied from
one main having two branch pipes leading therefrom, one to each cylinder,
so that both shall rise or fall at the same rate, and this main is fed by an
bydraulic accumulator, or by a force pump or pumps, which may be situate
conveniently to the hand of the gunner who points the gun. Concentric with
the trunnions on each side of the gun there is fitted in any convenient
manner a circular disc, or segment of a circle, or segment of any other. more
suitable curve in a vertical plane on the edge or not, and to the upper part
of each of these segments is secured one end of a chain, which is wrapped
round the segment, the other end of which is secured to the lower part of the
carriage at the proper distance from the front or rear thereof, determined by
the required angle for the chain to make with the horizontal part of the
carriage; as the "preponderance" or greater weight of the gun is at the
breech end of the trunnions, the weight of this rear portion will always
tend to maintain the two chains taut. On elevating the trunnion slide blocks
by the action of the hydraulic rams, the consequent strain or pull upon the
chains by acting upon the segments above referred to will tend to turn the
gun upon its trunnions in a vertical plane, and this rotatory action is so
regulated that, combined with the lifting of the gun parallel to itself, it shall
maintain the axis of the gun at the muzzle at the same level whatever may
be the height of the trunnions of the gun within its limits of elevation
or depression.
According to another arrangement the bydraulic cylinders and rams may
be situate horizontally or diagonally in or on the carriage. In this case the
sliding blocks which carry the trunnions may be suspended between the
guiding cheeks by chains or other wrapping connectors, which may pass
through guide or other pulleys attached to parts of the carriage, and be acted

page_text: on by the two horizontal rams. Combinations of rods and link work may be.
also applied to form the connections between the moving power, whether
bydraulic press, screws, or otherwise (when situated as here described) and
the gun trunnions. The blocks containing the trunnions being thus raised or
lowered, as before described. The muzzle of the gun is maintained at a
uniform level during the raising or lowering of the body of the gun by the
arrangement berein-before described with reference to the first modification.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Robert Mallet in the Great Seal Patent Office on the
24th May 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
MALLET, of 11, Bridge Street, in the City of Westminster, Engineer, send
greeting.
⚫ WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of November, in the year of our Lord
One thousand eight hundred and sixty-five, in the 29th year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Robert Mallet, Her special license that I, the said Robert Mallet, my execu-
tors, administrators, and assigns, or such others as I, the said Robert Mallet,
my executors, administrators, or assigns, should at any time agree with, and
no others, from time to time and at all times thereafter during the term therein
expressed, should and lawfully might make, use, exercise, and vend, within
the United Kingdom of Great Britain and Ireland, the Channel. Islands,
and Isle of Man, an Invention for "IMPROVEMENTS IN MOUNTING ORDNANCE,"
upon the condition (amongst others) that I, the said Robert Mallet, my
executors or administrators, by an instrument in writing under my hand
and seal, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and cause
the same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters Patent.
NOW KNOW. YE, that I, the said Robert Mallet, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement, reference being had to the accompanying Drawings, and to the
letters and figures marked thereon, that is to say: -
My said Invention relates to an improved. mode of mounting what are

page_text: known as muzzle-swivelling ordnance, so that the gun can be fired through
an embrasure or aperture but a little larger than the muzzle of the
gun itself,
and whereby the pointing of the gun is accomplished by a simple and more
effective arrangement than those hitherto proposed for this purpose.
My improved system or mode of pointing muzzle-swivelling guns is appli-
cable in batteries or casemates, or ships or vessels afloat, and depends on the
following well-known principle, namely, if a finite right line move through a
given are as radius vector on one of its extremities as a centre, the same
successive positions may be given to the line by causing it to move "parallel
to itself through any chord within its length, and to rotate through a given
angle round the point of intersection of this chord with the line or some other
point in the line. This principle may be applied in various ways, as hercin-
after described, to the pointing of muzzle-swivelling ordnance, the longitudinal
axis of the gun itself being the finite right line above referred to.
According to my Invention the pointing of the gun at any angle in a vertical
plane within the limits of its elevation or depression is effected by two com-
bined forces, the one tending to lift the gun bodily parallel to itself, whilst the
second force, acting in conjunction with the first, tends to cause the gun to.
rotate round the axis of its trunnions, the effect of which two combined
motions simultaneously acting is to maintain the centre of the actual muzzle
of the gun constantly at the same level, whatever may be the angle elevation.
or depression of the gun. Both these motions are brought into play simul-
taneously by the force employed for raising or lowering vertically or nearly
vertically the trunnions of the gun; this may be accomplished either by
the aid of bydraulic cylinders, elevating screws, or other equivalent con-.
trivances.
One mode of practically carrying out my Invention consists in mounting the
trunnions of the gun in two metal blocks which are free to move up or down
between guiding cheeks in each side of the carriage; these blocks are secured.
to the heads of the rams of two hydraulic cylinders, which themselves rest
upon trunnions fitting into seats at the bottom of the opening left between the
guiding cheeks in each side of the carriage, or are suspended from strong
flanges at their upper edges so as to be easy of removal and replacement in
case of fracture, or are otherwise fixed to the gun carriage. The two bydraulic
cylinders may be both supplied from one main having two branch pipes
leading therefrom, one to each cylinder, so that both shall rise or fall at the
same rate, and this main is fed by an hydraulic accumulator, or by a force
pump or pumps, which may be situate conveniently to the hand of the gunner
who points the gun. Concentric with the trunnions on each side of the gun

page_text: there is fitted in any convenient manner a circular disc, or segment of a circle,
or segment of any other more suitable curve in a vertical plane, grooved on the
edge or not, and to the upper part of each of these segments is secured one
end of a chain, which is wrapped round the segment, the other end of which
is secured to the lower part of the carriage at the proper distance from the
front or rear thereof, determined by the required angle for the chain to make
with the horizontal part of the carriage; as the "preponderance" or greater
weight of the gun is at the breech end, the weight of this rear portion will
always tend to maintain the two chains taut. On elevating the trunnion
slide blocks by the action of the hydraulic rams, the consequent strain or pull
upon the chains by acting upon the segments above referred to will tend to
turn the gun upon its trunnions in a vertical plane, and this rotatory action is
so regulated that, combined with the lifting of the gun parallel to itself, it
shall maintain the axis of the gun at the muzzle at the same level whatever
may be the position of the trunnions of the gun within its limits of elevation
or depression.
Acccording to another arrangement the hydraulic cylinders and rams may
be situate horizontally or diagonally in or on the carriage; in this case the
sliding blocks which carry the trunnions must be connected with them by
suitable arrangements. The combination of chains and segments, herein-
before described, is given as the simplest arrangement by which the object
may be approximately effected, but combinations of levers, slides, or link work
are, by preference, applied to form the connections between the moving power,
whether hydraulic press, screws, or otherwise; and the gun trunnions, as
herein-before described.
And in order that my said Invention may be fully understood, I shall now
proceed more particularly to describe the same, and for that purpose shall
refer to the several Figures on the annexed Sheet of Drawings, the same
letters of reference indicating corresponding parts in all the corresponding
Figures.
Figure 1 of the annexed Sheet of Drawings represents a Diagram of the
simplest form I am acquainted with of applying the principle herein-before
described to a muzzle-swivelling gun. C is an elevation of a portion of a gun,
to each side of which there is secured a segment m'; to these segments aro
attached at the points o chains 1, the opposite ends of which are secured to
relatively fixed points F in the gun carriage. D, D', D³, represent the
trunnions at the lowest, the horizontal range, and the highest positions of the
gun. The direction of the fixed point F of each chain must be in a line
perpendicular to and bisecting the line p and p² that shall join the same:

page_text: point in the periphery of the segment at its lowest and highest positions, and
the longer the chain can be made the more nearly the axis of the gun at the
muzzle will maintain the same level throughout the entire range of elevation
and depression.
Figure 2 on the annexed Sheet of Drawings represents a side elevation of a
gun mounted in accordance with my said Invention; Figure 3 is a corre-
sponding plan of the same; and Figure 4 is a Diagram explaining the
principle of its movements or adjustment in a vertical plane.
A is the ordinary slide or other platform, suitable either for ships and
floating batteries or for land forts, by which the horizontal movement is given
to the gun; B is the gun carriage; C, the gun, with its trunnions D, D; and
E is the port-hole or embrasure. I prefer to make the gun carriage of
wrought-iron plates and internal strengthening bars, as shown in my Drawings,
but it may be made of wood or other suitable material, or other modes of
construction may be adopted if preferred. This carriage may be mounted on
wheels in the usual way, and has a vertical straight or slightly curved slot or
opening made in each side under the trunnions, the cheeks of which openings
are formed by strong bars a, a, forming parts of the carriage, and having
slightly V-shaped or rebated 'grooves on their opposite faces, along which the
trunnion blocks b, b, slide when raising or lowering the gun, or these faces
may be plain, and the trunnion provided with lateral guiding jaws; F, F, are
caps bolted to the tops of the vertical slots or openings. To the under side of
each of the trunnion blocks 6 there is secured a ram or plunger c of a
hydraulic cylinder d, the latter being let into the bottom of the slot, and sus-
pended by a strong flange e at its upper edge, so as to be capable of being
easily removed and replaced when requisite. In order to allow of the cylinder
adjusting or accommodating itself in its seat a small swelling or protuberance f
is formed on diametrically opposite sides of the bearing surfaces of the flanges
and transverse to the axis of the gun, upon which the cylinder is free to rock
or play slightly. The ordinary form of hydraulic jack or cylinder ram may
be used, but as it is convenient to have as short a cylinder as possible com-
patible with the desired range of elevation and depression of the trunnions, as
shewn by the red lines 1, 2, (Figure 2,) I prefer to make the ram telescopic,
the part c of the ram being made to slide within a hollow ram c', which latter
works within the cylinder itself. The bottom of the hollow ram should have an
enlargement or shoulder formed thereon in order to prevent it from being expelled
from the cylinder, and a ring or gland which is first passed on to the ram is
screwed into the top of the cylinder as shown; such ring or gland containing
the leather collar and forming a stop against which the shoulder bears when

page_text: the ram is full up, after which the inner ram c continues its upward move-
ment. It is obvious that other contrivances may be adopted for admitting of
the use of telescopic rams. The two hydraulic cylinders are connected
together by the cross pipe g, and are worked either from a single pump or
from separate force pumps h, h, situate either within the two hollow sides of
the carriage if of iron, or bolted to the outsides or insides thereof, whether
of wood or iron, as shown in my Drawings. In either case a portion of the
interior of the carriage, when of iron, may serve as the water cistern for feeding
the pumps, the water being supplied through openings provided with lids or
covers h¹; i, i, are the pipes which connect the pumps with the cylinders,
the pumps themselves being so constructed as to allow the water of the
hydraulic cylinders to be returned to the water reservoirs upon lowering the
gun; k, k, are the handles for working the pumps, which may be convenient
to the hands of the gunner when in the act of pointing the gun. On to one
or both the trunnions of the gun there is keyed a lever arm 1, the extremity of
which is, by the preponderance of the breech end of the gun, kept in contact
with a stationary inclined slide bar m bolted to each of the sides of the gun
carriage. As the trunnions of the gun are raised or lowered so as to raise or
lower the gun parallel to itself, the ends of the lever arms 1, 1, by sliding along
the inclined surface of the bars m, cause the gun at the same time to turn
upon its trunnions, and so maintain the axis of the gun at the muzzle at a
uniform or nearly uniform level. This will be clearly understood on referring
to the Diagram, Figure 4, wherein the black lines C, C', represent the longi-
tudinal axis of the gun or a finite right line at its highest and lowest eleva-
tion; D, D¹, are the trunnions in corresponding positions, and I, I, are the
lever arms secured thereto, and bearing against the stationary inclined surface
or slide bar m. The red lines 1, 3, and 2, 3, represent the extreme limits of
rise and fall of the gun, and 3 represents the muzzle or centre round which:
the gun rotates. The red line 3, 4, represents the axis of the gun when
horizontal. The angle of the slide bar m depends upon the length of the
arins 7, that is to say, the shorter the arms the less will be the angle of the.
bar or surface m from the vertical, and vice versa. The length of the arm
being given, the bar or surface m must be adjusted to such an inclination
that the angle 6, 5; 7, produced by the arms 1, 1, at their highest and lowest
position will be equal to the angle 1, 3, 2.
:
Figure 5 represents another mode of raising and lowering the gun, namely,
by the the aid of elevating screws, and Figure 6 is a corresponding plan of the
same. c represents one of two elevating screws severally secured to the two
trunnion blocks b, so as not to rotate therein. These screws work into nuts d

page_text: pro-
fitted into a wrought-iron block at the bottom of the vertical slots in the two
sides of the gun carriage, and free to rotate therein. At the lower end of
these nuts, which are extended downwards sufficiently far to enable the shaft h
to clear the gun at its lowest position, there is keyed or otherwise secured a
worm wheel i, into each of which gears a worm carried by the transverse
shaft h. This shaft is rotated by the hand wheels k, k, and in order to prevent
any longitudinal thrust or end-on strain upon the bearings of the shaft I
pose to make the worms' right and left handed respectively, so that the lateral
strain or thrust of one should be neutralised by the other, the elevating
screws c being also right and left. The trunnion blocks 6 fit into and work
between the cheeks a, a, of the vertical slots or openings, which may be made
in any suitable manner as already described. The rest of the parts and the
motions of the gun are similar to those herein-before described and illustrated
at Figures 2, 3, and 4 of my Drawings. On imparting a rotatory motion to
the shaft and worm wheels through the hand wheels k, k, the rotation of the
nuts d thereby produced will cause the elevating screws c to rise or fall, and
carry the gun along with them.
Figure 7 représents a Diagram of another arrangement for pointing a
muzzle-swivelling gun, but based upon the principle herein-before set forth.
In this case I substitute a curved bar or sector secured to each side of the
gun for the lever arms / before referred to; and a stationary antifriction roller
or stud m fitted to the inner side of each cheek of the carriage. The curved
bars or sectors are kept in contact with their corresponding studs by the
preponderance of the breech end of the gun. The curve of these sectors m
must be so disposed in relation to the roller or stud.m and the axis of the gun
that the raising or depressing of the trunnions D along the vertical slots. in
the cheeks of the gun carriage shall have the effect of always keeping the
muzzle of the gun at the same level.
Figure 8 is a Diagram of another mode of applying the principle above
referred to. A is a stud secured to the gun below the trunnions at each side;
B, C, is the oblique line which this stud must traverse in order to bring the
muzzle of the gun round as the trunnions T rise vertically, B representing
the lowest and C the highest position of this stud; F is an axis which is fixed
to the gun carriage and carries the rocking lever arm D; A; D, is a radius
bar jointed at one end to the rocking lever D, and vibrating also on the fixed
axis F, the opposite end of this bar being passed over the stud A on the gun
by an eye with some freedom at the rear end to avoid any jar on. the radius
bar A, D, by the recoil of the gun; K represents a circular segmental guide
fixed to the gun carriage, against which the brass or bearing G carried by the

page_text: radius bar is caused to bear by the preponderance of the breech end of the
gun. The radius of the segment guide K is such that the point A moves in
the right line B, C, and is determined in the same way as the. short radius
bar M, N, in the, Diagram of the slightly modified arrangement,. Figure 9,
wherein I have represented the ordinary and well-known parallel motion, the
radius bar M, N, being substituted for the segmental guide K of the last-
described modification, the principle being the same in both.. The point.M
is fixed to the gun carriage and the point N to the long radius bar A, D, the
rest of the letters correspond to those of the Diagram, Figure 8, already
described.
The several arrangements herein-before described assume that the gun, has
the ordinary or some preponderance in the rear of the trunnions, but it is
obvious that the guiding arrangements may be so modified that they shall
produce the same effects upon a gun that has no preponderance or is in equi-
librium upon its trunnions. Although I have not shown any arrangement in
connection with the gun carriage for checking the recoil by friction in relation
to the slide, it is obvious that such may be applied to carriages constructed.
according to this Invention.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried
into effect, I would observe in conclusion that what I consider to be novel and
original, and therefore claim as the Invention secured to me by the herein-
before in part recited Letters Patent is,―
First, the general system or mode of mounting muzzle-swivelling ordnance,
substantially as herein-before described and illustrated by my Drawings.
Second, the system or mode of pointing ordnance by the combined effects
of two simultaneous motions, the one tending to lift the gun bodily parallel to
itself, whilst the other, acting in conjunction with the first, tends to cause the
gun to rotate round the axis of its trunnions.
Third, the combination of a chain and segment with a muzzle-swivelling
gun, operating substantially as and for the purpose herein-before described and
illustrated by Figure 1 of my Drawings.
Fourth, the combination of a lever arm secured to the trunnions of the
gun and a stationary incline slide bar or surface or surfaces, arranged and
operating substantially as and for the purpose herein-before described and
illustrated by Figures 2, 3, 4, 5, and 6 of my Drawings..
Fifth, the combination of a curved or other slide bar or bars attached to
the gun and a relatively [stationary stud or antifriction roller or rollers,

page_text: arranged and operating substantially as and for the purpose herein-before
described and illustrated by Figure 7 of my Drawings.
Sixth, the application and use of a radius link or links combined with and
operating upon a muzzle-swivelling gun, substantially in the manner and for
the purpose herein-before described and illustrated by Figures 8 and 9 of
my Drawings.
Seventh, the combination of any of the before-mentioned appliances for
turning a gun on the axis of its trunnions with hydraulic cylinders and
rams, elevating screws, or other equivalent mechanism operating either below
or above the trunnions with a view to the raising or lowering of the same,
substantially as and for the purpose herein-before described.
In witness whereof, I, the said Robert Mallet, have to this my Specifi-
cation set my hand and seal, the Twenty-third day of May, One
thousand eight hundred and sixty-six.
RODERI MALLET. (U.S.)