IMPROVEMENTS IN BREECH LOADING FIRE-ARMS
Year: 1882

page_text: LETTERS PATENT to John Robertson of George Yard Wardour Street in the
County of Middlesex Gun Maker for an Invention of "IMPROVEMENTS IN
BREECH LOADING FIRE-ARMS "
PROVISIONAL SPECIFICATION left by the said John Robertson at the Office
of the Commissioners of Patents on the 15th June 1882
JOHN ROBERTSON of George Yard Wardour Street, in the County of Middlesex
Gun Maker "IMPROVEMENTS IN BREECH LOADING FIRE ARMS
"
This Invention has for its object improvements in breech loading fire arms, and
relates especially to double barrel guns in which the barrels are mounted upon a
transverse horizontal pin or axis, and in which the breeches are opened by the
movement of the barrels about this pin or axis; the muzzles being depressed whilst
the breeches are raised and exposed to receive the cartridges.
My gun is provided with internal hammers or tumblers, and these are operated
by coiled springs. The springs are lodged in grooves or recesses on either side of
the body and in front of the hammers or tumblers and they thrust upon them at
the lower part or beneath the studs upon which they work.
There is a stem jointed to each bammer or tumbler and it passes forward through
the interior of the coiled spring. At its forward end the stem is bent inwards and
made to engage with or enter a slot in the side of the hook or lump beneath the
barrels which catches upon the pin or axis about which the barrels turn.
The hammers or tumblers are cocked by the act of opening the gun, the slots in
the hook or lump being so formed as to cause the stems jointed to the hammers or
tumblers to be drawn forward as the breeches open. The hammers are then caught
and retained by sears in the usual way.
Or each stem may be jointed at its forward end to one extremity of a bent lever,
the other extremity entering the cavity in the body into which the hook or lump

page_text: is received. The hook or lump is then so formed that in leaving its place in the
body it thrusts back the ends of the bent levers against which it abuts.
The head of each hammer or tumbler as it is brought to full cock raises and
passes a safety hook which is jointed to the tang of the body. Immediately the
hammer or tumbler has passed the safety hook returns being caused to do so by a
spring and consequently the hammer or tumbler cannot fall until the safety hook
has been removed, even should the sear fail to hold it. When however the trigger
is drawn back in the act of firing the safety hook is raised immediately before the
hammer or tumbler is released by the sear, this is effected by a stem jointed to the
safety hook and descending to the trigger and the trigger pushes upon it at the
proper moment. In place of a hook jointed to the tang I may employ a safety bolt
sliding therein with a spring and which at the instant of firing is displaced by the
trigger as already described in respect to the safety hook.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Robertson in the Great Seal Patent Office on the
15th December 1882.
JOHN ROBERTSON of George Yard Wardour Street in the County of Middlesex
Gun Maker IMPROVEMENTS IN BREECH LOADING FIRE ARMS."
#1
This Invention has for its object improvements in breech loading fire arms, and
relates especially to double barrel guns in which the barrels are mounted upon a
transverse horizontal pin or axis, and in which the breeches are opened by the
movement of the barrels about this pin or axis; the muzzles being depressed whilst
the breeches are raised and exposed to receive the cartridges. The locks of such
guns I provide as is now commonly done with internal hammers or tumblers which
are set back to full cock each time that the breech is opened. The setting back of
the hammers to full cock at the time of opening the breech I effect as hereinafter
described and illustrated at Figures 1, 2, 3, 4 and 5.
Each hammer or tumbler as it is brought to full cock I also cause to raise and
pass behind a safety hook which is jointed to the tang of the body. Immediately
the hammer or tumbler has passed, the safety book is by means of a spring made to
descend in front of the hammer and consequently the hammer or tumbler cannot
fall until the safety hook has been removed, even should the sear fail to hold it.
When however the trigger is drawn back in the act of firing the safety hook is
raised immediately before the hammer or tumbler is released by the sear, this is
effected at the proper moment by the movement of the trigger.
In the drawings hereunto annexed I have shewn examples of safety hooks
applied as above described to different forms of locks of breech loading fire arms.
Figure 1 is a longitudinal section and Figure 2 a plan view of the body of a
breech loading fire arm fitted with one form of lock and safety hook. Figure 3
shows separately a side elevation of one of the locks and Figures 4 shew separate
views of its internal hammer. Figure 5 shews a longitudinal section of the body-
in this figure the hammer of one of the locks is represented as caught by its safety
hook.
A is the body. B the pin at its forward end about which the barrels turn in the
ordinary manner. C is the ordinary locking bolt operated by a lever arm D. E is
the hammer of each lock operated by a coiled spring F. The spring surrounds a
rod G which is jointed to the hammer below the stud or axis upon which the
hammer turns. The rod lies along the inside of the front end of the lock plate and
passes through a guide H fixed to this plate. The guide H also forms an abutment
for the spring F to rest against. The opposite end of the spring bears against a
shoulder upon the rod G. I is a pin projecting inwards from the end of the rod G
its end passes into the slot K in the body into which the lump on the under-side
of the barrels enters in the ordinary way. The pins I of the two locks enter slots L
in the opposite side of the lump-the slot on one side of the lump is shewn at
Figure 1.
When the gun is opened the pins I are by the form of the slots drawn forwards
and the hammers so set back until they are caught by the sears.
In place of the slots being formed in the sides of the lump on the underside of
the barrels they might be formed in two small plates placed one on either side of
the lump and made to pivot on the pin upon which the barrels turn, and also to
extend forwards a distance beyond his pin so that when the barrels are turned on
the pin the plates shall turn also.
.M are the safety hooks jointed to the underside of the tang. N are springs which
turn the hooks downwards. O is a link jointed to the hook near its rear end. The

page_text: lower end of the link enters a small hole drilled into the top of the trigger. It will
be seen that when the trigger is pulled the hook turns upwards. P is a projection
at one side of the hammer. The rear end of this projection is inclined and when
the hammer is set back to full cock the incline passes below and lifts the hook.
When the projection P has passed beyond the hook the spring N returns the hook
to its former position. Should the hammer then be jarred off or escape from the
sear without the trigger being pulled the hook will catch the front end of the
projection P and hold back the hammer.
At Figure 6 I have shewn how a safety catch may be similarly applied to
another form of lock which is of well known construction. With this lock the
hammer is set back to full cock at the time when the breech is opened by means
of a lever R. The lever is made to turn by the barrels as they turn down to open
the breech, as the forward end of the lever enters a recess in the lever O which is
secured to the underside of the barrels as usual. The hammer of the lock is shewn
set back at full cock and caught by the sear.
M. is the safety catch jointed at its upper end to the under side of the tang. At
its lower end it has a small pin projecting from it which comes above a small
incline on the top of the trigger. The safety catch is formed with a small
projecting nose to come in front of a corresponding nose on the top of the hammer
when the hammer is set back to full cock.
The action of the safety catch is just the same as in the construction shewn at
Figures 1 to 5. It is pressed away by the hammer, when the hammer is set back
and is returned by a spring after the hammer has passed, and is similarly moved
out of the way of the hammer when the trigger is pulled but catches the hammer
if in any way it gets released from the sear without the trigger being pulled.
Figures 7, 8 and 9 shew a modification of the construction shewn at Figure 6.
Figures 7 and 8 are longitudinal sections. In Figure 7 the hammer is shewn to be
down. In Figure 8 it is shewn caught by the safety catch M.
It will be seen that the bent lever forming the safety catch is set more forward
and that a slot is formed in it through which the upper end of the hammer E
passes when it is set back to full cock. The slot is shewn in Figure 9 which is a
cross section through the line A, B Figure 8. It will also be seen that the nose
which is to be caught by the safety catch is at the back of the hammer instead of
on the top of the hammer as shewn at Figure 6.
In the arrangement shewn at Figures 1 and 5 the safety hook M instead of being
jointed by a pin joint to the tang might be formed at the front end of a long
spring which is secured at its rear end to the tang as shewn by the dotted lines R
in figure 1. A link O would then be carried down from the spring to the
trigger.
Or in place of the spring R being fixed to the tang it might be fixed to the
trigger plate as shewn at Figures 10 and 11. In this case a pin standing out from
the side of the spring is made to come above the trigger. The pin stands out from
one side of the spring the catch stands out from the opposite side as shewn in the
plan view of the spring at Figure 12. If preferred the rear end of the spring
might be secured to the side lock plate instead of to the trigger plate. In Figure 10
the hammer is shown to be down-the safety catch then rests on the top of a
projection standing out from the side of the hammer. When the hammer is set
back to full cock the spring moves the catch down so that it comes in front of this
projection and if the hammer escapes from the sear the projection on the hammer
is caught by the catch as shewn at Figure 11.
Having thus described the nature of my Invention and the manner of performing
the same I would have it understood that I do not claim generally the employment
of a catch to prevent the harumer from falling should it escape from the sear
without the trigger being pulled as various arrangements of safety catches to act in
this manner have before been proposed but I claim :-
First. The combinations of safety catch mechanism substantially as hereinbefore
described with reference to Figures 1 to 5

page_text: Second. The combination of safety catch mechanism substantially as hereinbefore
described with reference to Figure 6.
Third. The combination of safety catch mechanism substantially as hereinbefore
described with reference to Figures, 7 8 and 9.
Fourth. The combination of safety catch mechanism substantially as herein before
described with reference to figures 10 and 11.
Fifth. The combination of mechanism for setting the hammers back to full cock
at the time when the breech is opened substantially as herein before described with
reference to figures 1 to 5 and the modification of this combination
In witness whereof I the said John Robertson have hereunto set my hand
and seal this Fifteenth day of December in the year of our Lord One
thousand eight hundred and eighty two.
JOHN ROBERTSON (LS)
.
JOHN ROBERTSON (Ls.)}