IMPROVE- MENTS IN MACHINE OR BATTERY GUNS
Year: 1879

page_text: LETTERS PATENT to John Frederic Trotter, of No. 20, Southampton Buildings,
Chancery Lane, in the County of Middlesex, for the Invention of "IMPROVE-
MENTS IN MACHINE OR BATTERY GUNS."
Sealed the 8th April 1879, and dated the 7th February 1879.
PROVISIONAL SPECIFICATION left by the said John Frederic Trotter at the
Office of the Commissioners of Patents on the 7th February 1879.
JOHN FREDERIC TROTTER, of No. 20, Southampton Buildings, Chancery Lane,
in the County of Middlesex. "IMPROVEMENTS IN MACHINE OR BATTERY GUNS."
My Invention relates to a construction of "machine" or "battery gun," for which
Letters Patent were granted to W. R. Lake, as a communication from F. L. Bailey,
on the 21st April 1876, No. 1703.
According to my present improvements I construct such guns as follows:-The
gun barrels, which receive a longitudinal motion in a revolving frame by means of
feathers or studs thereon working on or in cam guides on the inner surface of the
fixed framing, as in the original arrangement, are made of equal external diameter
throughout their length, instead of tapering as before, and the holes in the front
revolving disc through which they slide are slotted, so that when the frame with
the cam guides is opened the barrels can be separately drawn out at the front ends,
their studs or feathers passing through the slots of the disc.
The cam guides on the inner faces of the opening gun frame, which have hitherto
been fixed thereon, are by preference made as loose pieces, fitting with studs into
the cylindrical frame. By this means, when the barrels are replaced in the gun
after removal, they can be readily adjusted into their proper positions relatively to
the cam guides, the frame remaining open while this is being done. On closing the
frame the studs on the guides enter the holes in the frame, and are thus securely
held thereby. In place of or in addition to the above arrangement a loose
gauge may be provided, having a configuration corresponding to the cam guides, so
that by applying such cam gauge to the front end of the gun frame, and sliding in

page_text: the barrels until their muzzles are in line with the cam shaped face of the gauge,
their studs will be brought into the proper position for fitting the cam guides.
The central-spindle-or-shaft by which the barrels are rotated may be made hollow,
so as both to lighten it and impart elasticity thereto. At the rear end it has fixed-
on it the lever or crank-handle by which it is rotated, and this lever carries a sliding
piece or disc of circular-form-which can be adjusted thereon from a position in which
the centre of the disc coincides-with-the-centre-line of the revolving shaft into a
position in which the disc is considerably excentric to the shaft. The said disc is
situated between projecting cheeks on the support-for-the-breech-of-the-gun frame,
so that when the disc is adjusted excentrically to the shaft it will, in being rotated
-with-the latter, at the same time cause it, and also the barrels and frame, to sweep
or traverse horizontally backwards and forwards, so as to spread the fire more-or-
less. The degree of such excentricity, and consequently the extent of the traverse,
is regulated either by a link connected to the sliding disc and to a slide on the
lever, so that by adjusting this slide by hand to a scale marked on the lever, and
then fixing its position by a setting screw, the disc is brought to the required
degree of excentricity; or the adjustment may be effected by a screw screwed
through the upper end of the lever, and connected to or acting on the disc. The
breech end of the gun frame is formed in plan as an arc, the radius of which is
taken from the centre on which the gun is pivotted, and it has a dovetailed feather,
which slides to and fro in a dovetail groove in the correspondingly curved face of
the supporting piece; this latter is carried by an elevated screw swivelling in a loop
pivotted to the supporting piece, and screwing through a socket mounted so as to
swing in bearings on the gun carriage.
In place of mounting the gun on side trunnions, as before, it is carried by a ball
and socket or other suitable support placed centrally beneath it, which permits both
the vertical and horizontal angling of the gun; the spherical socket is formed or
fixed on a slide that can be traversed in a transverse groove on the carriage for the
purpose of fine sighting the gun, such traversing being effected by a toothed pinion
in gear with a rack on the slide, and turned by means of a spindle extending
towards the breech of the gun, where it is provided with a hand wheel.
The socket is made in two halves, the lower half being fixed to the traversing
slide, while the upper half is removeable for introducing the ball; it is for this
purpose by preference also inade in two halves, hinged together at one side, so that
when the ball on the gun has been placed in the lower part of the socket the upper
hinged half is made to embrace the ball, and is then secured by a screw or catéh.
The ball has a stem which is screwed into the underside of the gun, so that it can
be readily removed by unscrewing should it become damaged, and be replaced by
another one. The hole in the socket through which the stem passes is slotted in
the direction of the axis of the gun, so that this can be brought to any inclination
in the vertical plane of its axis for firing, and can also be turned to any hori-
zontal angle, but the sides-of-the-slot-in-the.socket prevent the gun from tilting
over laterally.
The cartridge holders instead of being fixed to the belt by which they are fed
into the gun, as described in the before-mentioned Patent; are formed at bottom
with long narrow loops, through which the belt is threaded; the under portions of
the loop serve as the ribs of the belt that fit into the grooves of the revolving space
wheel, by which they are brought consecutively into position for firing: The ribs
and grooves may be of slightly bevilled form, so as to readily fit each other. The
holders may be provided with lateral arms for keeping them the proper distances
apart on the belt, and the end of the latter, which is first introduced into the gun,
may be provided with a roughened tongue of metal or other rigid material, so as to
be readily laid hold of by the revolving space wheel.
For directing the cartridge belt into gear with the latter a curved guide is pro-
vided, carried by the gun frame.
In order to prevent the gun being rendered useless when in action; either by the

page_text: ordinary cartridge belts being all expended or owing to their having been delayed
in transit, I provide on the gun carriage a box containing a length of belt with the
cartridge holders, which belt can be passed through the gun and over a guide pulley
provided below, and then have its two ends connected together so as to form an
endless belt. At a convenient point a small hopper or receiver is placed, through
which any cartridges supplied to the troops are inserted into the cartridge holders
of the belt as these pass out of the gun on one side, which cartridges are then
carried on by the belt and into the feeding side of the gun again. Such cartridge
belt, as also those ordinarily used with the gun, are by preference made of such
material or compound of different materials that will not be readily affected by heat
or moisture.
The entire gun with its frame is enclosed by a light metal casing, on which lateral
sights are provided for range finding and for aiming at such ranges.

page_text: JOHN FREDERIC TROTTER,-of-No.-20, Southampton Buildings, Chancery Lane, in
the-County of Middlesex. IMPROVEMENTS IN MACHINE OR BATTERY GUNS:"
My Invention relates to a construction of "machine" or "battery guns."-for-which-
Letters Patent were granted to W. R. Lake, as a communication from F..L. Bailey,..
on the 21st April 1876, No: 1703.
According to my present improvement I construct such guns as follows:-The
gun barrels, which receive a longitudinal motion in a revolving frame by means of
feathers or studs thereon, working on or in cam guides on the inner surface of the
fixed framing, as in the original arrangement, are made of equal external diameter
throughout their length instead of tapering as before, and the holes in the front
revolving disc through which they slide are slotted, so that when the frame with
the cam guides is opened the barrels can be separately drawn out at the front ends,
their studs or feathers passing through the slots of the disc.
The cam guides on the inner faces of the opening gun frame, which have hitherto
been fixed thereon, are by preference made as loose pieces, fitting with studs into
the cylindrical frame. By this means when the barrels are replaced in the gun
after removal they can be readily adjusted into their proper positions relatively to
the cam guides, the frame remaining open while this is being done. On closing the
frame the studs on the guides enter the holes in the frame, and are thus securely
held thereby. In place of or in addition to the above arrangement a loose gauge
may be provided having a configuration corresponding to the cam guides, so that by
applying such cam gauge to the front end of the gun frame and sliding in the
barrels until their muzzles are in line with the cam shaped face of the gauge, their
studs will be brought into the proper position for fitting the cam guides.
The central spindle or shaft by which the barrels are rotated may be made
hollow, so as both to lighten it and impart elasticity thereto. At the rear end it
has fixed on it the lever or crank handle, by which it is rotated, and this lever
carries a sliding piece or disc of circular form which can be adjusted thereon from
a position in which the centre of the disc coincides with the centre line of the
revolving shaft into a position in which the disc is considerably eccentric to the
shaft. The said disc is situated between projecting cheeks on the support for
the breech of the gun frame, so that when the disc is adjusted eccentrically to the shaft
it will in being rotated with the latter at the same time cause it and also the barrels
and frame to sweep or traverse horizontally backwards and forwards so as to spread
-the-fire-more or less. The degree of such eccentricity, and consequently theextent
of the traverse, is regulated either by a link connected-to-the-sliding-disc.and.to_a_
slide on the lever, so that by adjusting this slide by hand to a scale marked on the
lever, and then fixing its position by a setting screw, the disc is brought to the
required degree of eccentricity, or the adjustment may be effected by a screw
screwed through the upper end of the lever and connected to or acting on the disc.
The breech end of the gun frame is formed in plan as an arc, the radius of which
is taken from the centre on which the gun is pivotted, and it has a dovetailed
feather which slides to and fro in a dovetail groove in the correspondingly curved
face of the supporting piece. This latter is carried by an elevating screw swivelling
in a loop pivotted to the supporting piece, and screwing through a socket mounted
so as to swing in bearings on the gun carriage.
In place of mounting the gun on side trunnions as before it is carried by a ball
and socket or other suitable support placed centrally beneath it, which permits both
the vertical and horizontal angling of the gun. The spherical socket is formed or
fixed on a slide that can be traversed in a transverse groove on the carriage for the

page_text: purpose of fine sighting the gun, such traversing being effected by a toothed pinion
in gear with a rack on the slide, and turned by means of a spindle extending
towards the breech of the gun, where it is provided with a hand wheel.
or
The socket is made in two halves, the lower half being fixed to the traversing
slide, while the upper half is removeable for introducing the ball. It is for this
purpose by preference also made in two halves hinged together at one side, so that
when the ball on the gun has been placed in the lower part of the socket the upper
hinged half is made to embrace the ball, and is then secured by a screw
catch. The ball has a stem, which is screwed into the underside of the gun, so that
it can be readily removed by unscrewing should it become damaged and be replaced
by another one. The hole in the socket through which the stem passes is slotted
in the direction of the axis of the gun, so that this can be brought to any inclination
in the vertical plane of its axis for firing, and can also be turned to any horizontal
angle, but the sides of the slot in the socket prevent the gun from tilting over
laterally.
The cartridge holders, instead of being fixed to the belt by which they are fed
into the gun, as described in the before-mentioned Patent, are formed at bottom
with long narrow loops, through which the belt is threaded. The under portions
of the loop serve as the ribs of the belt that fit into the grooves of the revolving
space wheel, by which they are brought consecutively into position for firing. The
ribs and grooves may be of slightly bevilled form, so as to readily fit each other.
The holders may be provided with lateral arms for keeping them the proper distances
apart on the belt, and the end of the latter, which is first introduced into the gun,
may be provided with a roughened tongue of metal or other rigid material, so as
to be readily laid hold of by the revolving space wheel.
For directing the cartridge belt into gear with the latter a curved guide is pro-
vided carried by the gun frame.
In order to prevent the gun being rendered useless when in action, either by the
ordinary cartridge belts being all expended or owing to their having been delayed
in transit, I provide on the gun carriage a box containing a length of belt with the
cartridge holders, which belt can be passed through the gun and over a guide pulley
provided below and then have its two ends connected together so as to form
an endless belt. At a convenient point a small hopper or receiver is placed through
which any cartridges supplied to the troops are inserted into the cartridge holders
of the belt as these pass out of the gun on one side, which cartridges are then carried
on by the belt and into the feeding side of the gun again.
Such cartridge belt, as also those ordinarily used with the gun, are by preference
made of such a material or compound of different materials that will not be readily
affected by heat or moisture.
The entire gun with its frame is enclosed by a light metal casing on which lateral
sights are provided for range finding and for aiming at such ranges.
:
DESCRIPTION OF THE DRAWINGS
Fig. 1 is a side elevation of the before described improved battery gun; Fig. 2
shews a longitudinal section to an enlarged scale; Fig. 3 shews a sectional front
end view, and Fig. 4 shews a plan of the under support; Fig. 5 shews a longitudinal
section of the breech end of the gun to a still larger scale; Figs. 6 and 7 shew end
views of the same; Fig. 8 shews a plan, and Fig. 9 shews a cross section. The gun
consists mainly of a casing or frame A, A³, mounted on a support S and carriage B,
and carrying within it a shaft C capable of rotation by means of the crank handle D.
On this shaft are fixed dises E, E, having holes round their circumference in which
gun barrels F, F, are free to slide backwards and forwards parallel to the shaft C,
the barrels receiving such longitudinal motion as they are carried round by the
shaft C by means of a cam guide G attached to the casing A. and taking into notches
the tal
Fig. 1 is a side elevation of the before described improved battery gun; Fig. 2
shews a longitudinal section to an enlarged scale; Fig. 3 shews a sectional front
end view, and Fig. 4 shews a plan of the under support; Fig. 5 shews a longitudinal
section of the breech end of the gun to a still larger scale; Figs. 6 and 7 shew end
views of the same; Fig. 8 shews a plan, and Fig. 9 shews a cross section. The gun
consists mainly of a casing or frame A, A³, mounted on a support S and carriage B,
and carrying within it a shaft C capable of rotation by means of the crank handle D.
On this shaft are fixed dises E, E, having holes round their circumference in which
gun barrels F, F, are free to slide backwards and forwards parallel to the shaft C,
the barrels receiving such longitudinal motion as they are carried round by the
shaft C by means of a cam guide G attached to the casing A. and taking into notches
in feathers Fou the barrels, which cam is so formed, as shown in the development

page_text: thereof at Fig. 10, that as the barrels revolve round that part of the circumference
marked 1-2 at Figs. 3 and 10, they are moved forward some distance away from a
disc H fixed on the shaft while they travel; from 2 to 3 they are maintained in such
forward position; from 3 to 4-they-approach-the-disc again; from 4 to 1 they are
held firmly close against it both-by-the cam G. and by a second cam G₁, as during-
that time, namely, when the barrels arrive in the position marked X at Figs. 3, 5, 6,
-and-10-the-charge is fired; lastly, while travelling from 1 to 2 the barrels are moved
outwards again. The object of such longitudinal motion of the barrels is as follows :—
The cartridges-I-are-placed_in_holders J that are threaded on a belt of leather K
or other suitable material, as shewn in plan and section-at-Figs-1-1-and 12, and this
belt is introduced through an opening A¹ in the bottom of the casing and is led over
a drum L fixed on the shaft C, such drum being provided with longitudinal grooves
for the reception of the lower part J' of the cartridge holders as shewn at-Figs. 5
and 9, so that as the drum revolves the belt with the cartridge holders and cartridges
is caused to travel round with it towards the point X where the cartridge is fired
and thence out through the opening A¹ again. The distances of the cartridges on
the belt and the corresponding grooves of the drum are gauged to agree exactly
with the distances apart of the barrels F, so that as the cartridge holders pass on to
the drum each cartridge holder, and cartridge is situated exactly in line with the
barrel and with a corresponding striking pin H¹in the disc H, against which the
rear end of the cartridge fits closely. In order to enable the cartridge holders and
cartridges to assume this position on the drum the barrels must be moved forward
away from the disc H a distance slightly exceeding the length of the cartridge, and
such forward motion is imparted by the portion 1-2 of the cam guide G, as above
described, the barrels being kept in such forward position by the part 2-3 while
the cartridges are moving on to the drum, after which the barrels are moved back-
wards by the part 3-4 so as to close over the cartridges, as shewn at Fig. 5, and
while they are held firmly in this position by the part 4-1 the cartridge is fired.
The barrels are then again moved forward by the part 1-2 in order to allow the
belt with the empty cartridge cases to pass off the drum again and out through
the opening A¹. The firing of the cartridges as they arrive in the position at X is
effected as follows:-
In the breech end of the casing A is fixed a tube M. containing two spring
hammers M1, M2, each of which is of semi-circular cross section so as to fit the tube.
Each hammer is pressed forward by a spring M³, M, and has a tail M5, M6, pro-
jecting through a slot in the bottom of the tube M, the tail M5 of the hammer M'
being made to project down through a slot in the hammer M² as indicated. On the
shaft C are fixed two cam discs N1, N2, each of which has a series of cams on its
circumference, those on the disc N¹ being made to act on the tail of the hammer M¹
so as by their rotation to move the hammer back from its forward position to the
backward position indicated against tho action of the spring and then to let it fly
forward-so-as.to_strike the striking pin H', which is thereby made to fire the
cartridge presented to it. In like manner the cams-on-N2 act upon the hammer M²,
the two sets of cams being so arranged as to act alternately on the hammers so that
these fire alternate charges, that is to say, a cam on N2 having caused the hammer M²
to fire the cartridge in front of the striking pin H, as at Fig. 5, a cam on N¹ next
releases the hammer M¹ so as to strike the next pin H¹ presented to it and thus to fire
the cartridge in the next following barrel, and so on. It will be seen that the
striking pins H' are in such a position, that each one can receive the blow from
either the hammer M¹ or M2. The pins H¹ are held in the disc H by means of
screws H2 taking into grooves in the pins so as to allow these the requisite amount
of motion for striking. The discs E, E, carrying the barrels (which are of the same
diameter throughout), have slots E' at their circumference, and the top of the casing
A opens on binges at A, so that the cam guide G being thus raised out of the
notches in the feathers F¹ of the barrels, these can be drawn out of the framing at
the muzzle end when required, the slots E¹ permitting the feathers F1 to pass out.
For facilitating the setting of the barrels in position in the framing, the cam guides

page_text: G are by preference made as separate pieces from the casing, with studs G³ (Fig. 10)
fitting into holes in the casing, so that the barrels can be set accurately in position
relatively to the cam guides while the frame is open, and on closing the latter, the
pins G will enter the holes in the casing, and the cam guides will thus be held
securely thereby. In place of or in addition to this arrangement, a loose gauge or
template may be provided, having a configuration corresponding to the cam guides,
so that by applying this cam gauge to the front end of the gun frame, and sliding
in the barrels until their muzzles are in line with the face of the gauge, they will
be brought into proper position for the cam to fit into them. The shaft C, which is
by preference made hollow for the sake of lightness and elasticity, has fixed on its
rear end a crank lever D by which it is rotated. This lever carries a circular disc
O grooved on its front face so as to be capable of sliding up and down on the
lever, so as to assume any position thereon between the two limits indicated at
Figs. 6 and 7. To permit of this motion, the part behind the lever D has a slotted
hole O' through which the shaft C passes. The adjustment of the disc upon the lever
D is effected by means of a slide P sliding on the lower part of the lever D, and
connected to the back part of the disc O by a link P' and screw P2 passing through
a slot in the lever. The back part of the disc O fits between two cheeks Q¹ of the
saddle piece Q on which the breech end of the gun rests. When O is in the
position shewn at Fig. 6, that is with its centre coinciding with the centre of the
shaft C, and the shaft be rotated by means of the crank lever, there will be no
lateral motion of the gun, but when O is moved down, say, into the position shewn
at Fig. 7, and the lever be rotated, then owing to the eccentric position of the disc
relatively to the shaft, it will, in being rotated between the stationary cheeks Q',
impart to the breech of the gun a horizontal to and fro motion as indicated by the
dotted positions, Fig. 7, the gun turning upon its pivot at R, and thus the muzzle
end of the gun in receiving a similar lateral to and fro motion will cause the fire to
be spread to a corresponding extent. The lever has a scale marked upon it as
shewn at Fig. 6, so that the disc O can be set to any desired degree of eccentricity
by means of the slide P, to afford a certain amount of lateral motion and consequent
spread of fire. The slide has a setting screw P³ for securing it in the position in
which it is set.
The saddle piece Q on which the breech end of the gun casing rests, has a dove-
tail groove at Q2, in which fits a dovetail feather on the casing A, whereby the gun
is securely held on the saddle while moving to and fro laterally upon it as described.
The end surface of the breech and that of the saddle piece against which it works
are of course both curved to a radius corresponding to the centre of the pivot R, as
indicated on plan at Fig. 8. This pivot consists of a ball with stem screwed into a
stirrup A* fixed to the side bars A³ of the frame, and fitting in to a spherical socket
R¹, the top part of which consists of two separate halves hinged together and
secured by a screw R², so that by opening out the halves of the cap, the gun can be
removed from or fitted into the socket. The hole in the cap is slotted as shewn at
Fig. 4, so as to permit of the vertical angling of the gun in sighting, while the sides
of the slot prevent the gun from tilting over laterally. The socket R¹ is carried on
a slide R³ in a dovetail groove on the support S, the slide having a rack R* with
which gears a pinion S₁ on a spindle carried by the support S, and rotated by a
hand wheel, by which means the slide, and with it the pivot of the gun, can be
traversed laterally on its carriage for lateral fine sighting. The saddle piece Qis
connected to the elevating screw T by a link T jointed at T to allow of the
vertical angling of the gun as the screw is screwed up or down in its socket U, the
latter being hung on pivots at U in the support S, so as to follow the more or less
angular position assumed by the screw. The belts K carrying the cartridge holders
J are of any convenient length, and pass into the gun from a box Y on the carriage,
as shewn at Fig. 1, and when in use, the end of the belt passing through the gun
may be attached by any suitable fastening to the end of the next belt, so as to
insure an uninterrupted feed of cartridges in to the gun. A curved guide V,
Fig. 9, is provided attached to the gun frame for guiding the belt with its cartridge

page_text: F
holders correctly on to the drum L, and the belt may be provided with a metal
tongue at its entering end in order to facilitate it entering on to the drum. The
frame-of-the-gun-consists firstly of the cylindrical casing A above described, and
secondly of the strap A3 which is secured to each side of the casing-A, and.extends.
round the front end of the gun, where it serves as the bearing for the end of the
shaft C. This frame may-be-enclosed_in_a_light steel casing W, as shewn in the
elevation at Fig 1, which-casing is also made to open on hinges.
Having thus described the nature of my Invention, and in what manner the-
same is to be performed, I-claim-in-respect-of_machine or battery guns of the kind
herein referred to,-
First.. Supporting the gun barrels in discs, having slots at their circumference for
enabling the barrels to be withdrawn at the muzzle end, substantially as described.
Second. Constructing the cam guides for the barrel as separate pieces from the
casing, substantially as and for the purposes described.
Third. Regulating the lateral motion of the gun for spreading the fire by means
of a disc on the crank lever working between cheeks on the support, the eccentric
position of which disc is regulated by a slide and scale on the lever, substantially
as herein described.
Fourth. Supporting the gun on a ball and socket pivot, allowing both vertical
angling of the gun for sighting, and lateral motion for spreading the fire.
Fifth. Mounting the pivot of the gun on a slide capable of transverse motion on
the carriage for lateral sighting, substantially as described.
Sixth. Supporting the breech end of the gun in a saddle piece to which the
elevating screw is jointed, while the socket of such screw is mounted on trunnions
on the support, substantially as described.
Seventh. Constructing the cartridge holders with loops by which they are
threaded on to the belt, substantially as described.
Eighth. Providing a guide to the feed drum for guiding the cartridge belt into
position on the drum, substantially as described.
Ninth. Providing a steel casing for enclosing the whole of the gun, substantially
as described.
Tenth. The herein described combination of parts constituting the improved
machine or battery gun.
In witness whereof, I, the said John Frederic Trotter, have hereunto set my
hand and seal, this Sixth day of August, in the year of our Lord One
thousand eight hundred and seventy nine.
TOHN
TROTTER (rol