An Improvement in the Mounting of Moncrieff or Disappearing Guns.
Year: 1887

page_text: Date of Application, 15th Jan., 1887
Complete Left, 12th Oct., 1887
Complete Accepted, 15th Nov., 1887
PROVISIONAL SPECIFICATION.
An Improvement in the Mounting of Moncrieff or Disappearing
Guns.
I, ALEXANDER MONCRIEFF of No. 15 Vicarage Gates, Kensington in the County
of Middlesex, Colonel, do hereby declare the nature of this invention to be as
follows:-
My invention relates to the mounting of guns which, according to what is known
as the Moncrieff system, disappear on firing and take a position where they may be
charged or otherwise manipulated in shelter. The object which I have in view is to
counterbalance the gun in such a way that at the moment when the recoil begins to
act the strain on the counterweight is very small, but the counterweight becomes more
and more effective as the gun recoils until it Ginally brings it to rest, in which
position the gun is held until it is again released and caused to ascend to its firing
position.
For this purpose, the curved elevators which support the trunnions of the gun, and
which roll backwards along the platform or slide, are made of a special curvature and
have attached to them at their point of greatest radius (reckoned from the centre of
the trunnion) chains ropes or bands which carry counterweights that can descend in a
well or pit under the carriage. The point of attachment of each of these ropes bands
or chains to the curve of the elevator is such as to be coincident or nearly so with the
point of contact of the elevator curve with the platform when the gun is raised to its
firing position, and as each rope, band or chain passes over a pulley, this point of
attachment rises and moves backwards as the gun recoils in such a manner that the
counterweight exerts an increasing leverage to resist the recoil movement. Instead
of connecting the rope, chain or band directly to the counterweight it may be attached
to and wound partly round one pulley while the chain or its equivalent is attached to
and wound partly round another pulley on the same shaft, and either or both of these
pullies, instead of being circular, may be cam shaped so as to modify the action of the
weight at different parts of their revolution. To these pullies
or to the shaft on which
they are fixed, I apply a ratchet and pawl or a brake which allows them to revolve in
the one direction suited to the recoil movement, but prevents their reversal. By

page_text: working the pawl. by worm or other gearing, or releasing the brake, the weight causes
the gun to ascend to its firing position. The gun carriage rests on rollers running on
rails around the mouth of the well or pit and it has guide rollers within that mouth
so that it can turn round the centre of the well as an axis.
When the gun, instead of being mounted on curved elevators, is mounted on arms
working round fixed pivots, I apply to those arms curves round which the ropes
chains or bands strained by the counterweights are wound as the gun recoils, the
curves being such that the counterweight acts with more and more leverage as the
recoil movement goes on.
Dated this 15th day of January 1887

page_text: COMPLETE SPECIFICATION.
An Improvement in the Mounting of Moncrieff or Disappearing
Guns.
I ALEXANDER MONCRIEFF of No. 15 Vicarage Gates Kensington in the County of
Middlesex Colonel, 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 :-
My invention relates to the mounting of guns, which according to what is known
as the Moncrieff system, disappear on firing and take a position where they may be
charged or otherwise manipulated in shelter. The object which I have in view is to
counterbalanco the gun in such a way that, at the moment when the recoil begins to
act, the strain on the counterweight is very small, but the counterweight becomes
more and more effective as the gun recoils until it finally brings it to rest, in which
position the gun is held until it is again released and caused to ascend to its firing
position. When the gun is carried on curved elevators which roll backwards along
the platform or slide, I adopt the construction and arrangement shewn in Fig. 1 of
the accompanying drawings which represents the gun G in firing position and also
in dotted lines in the position to which it recoils. The trunnions T of the gun work in
bearings in the upper ends of the elevators E which are made of suitable curvature
and have attached to them the chains, ropes, or bands C that carry the counter-
weights W which descend in a well or pit under the gun carriage.
The attachınent of the chain C to the elevator E is at a point A coinciding or
nearly so with the point where the line of the platforın is tangential to the curve of
the elevator when the gun is in firing position.
The chain passes over a pulley P and as the gun recoils the point of attachment A
rises and moves backwards raising the counterweight W in such a manner that it
exerts an increasing leverage to resist the recoil movement. The elevator and platform
may be provided with teeth or cogs as shewn, to ensure the rolling of the elevators
without slip along the platform
Instead of simply passing the chain C from the counterweights over the pulley P
and attaching it to the elevator it may be attached to and wound partly round the
pulley P while another chain from the elevator is attached to and partly wound on
another pulley fixed on the same shaft with P. Either or both of these pullies,
instead of being circular may be cam shaped so as to modify the action of the weight
at different parts of their revolution.
To these pullies or to the shaft on which they are fixed I apply ratchets and pawls
with a brake, and manipulating gear which may be arranged as shewn by Figs. 14
and 1, Fig. 1 shewing the brake and ratchet, and Fig. 1 shewing the ratchet and
manipulating gear. On the shaft which carries the pulley or pullies P are fixed
two discs D, each carrying several spring pawls E and E' and on the shaft Q are
loosely fitted a brake wheel F having internal ratchet teeth engaged by the pawls E

page_text: and a spur wheel F' having internal ratchet teeth engaged by the pawls E. The
brake wheel F is surrounded by a brake band G having its lever loaded by a
weight g and the spur wheel F is connected by intermediate gear, which may be
worm gear, to a winch handle H Fig. 1. It will be seen that the pawls E E¹ are set
to act in opposite directions of revolution. When the gun recoils the pawls E carry
round with them the brake wheel F the friction of the brake band checking recoil,
but the other pawls E' slip without driving the spur wheel F. When the gun has
recoiled the pawls E' engaging with the teeth of F¹ prevent the gun from being raised
again by the weights, W, unless the gear commanded by the handle H be left free
or worked in the one direction whilst by working the gear in the opposite direction
the gun can be lowered from firing position.
The gun carriage rests on rollers R running on rails around the well, and it is
guided around the mouth of the well so as to turn round the centre of the well as an
axis.
When the gun, instead of being mounted on curved elevators, is mounted
on arms working round fixed pivots I apply to these arms curves round which the
ropes chains or bands strained by the counterweights are wound as the gun recoils,
the curves being such that the counterweights act with more and more leverage as
the recoil movement goes on. Fig. 2 represents a gun mounted in this
way.
The trunnions T of the gun G are mounted in bearings at the ends of lever arms L
which can revolve on the fixed pivot or transverse axis F. To the lever LI attach a
curved arm A round which the rope chain or band C suspending the counterweight W
it wound as the gun recoils as indicated at A¹. The chain C passes over a guide
pulley P so arranged that when the gun is in firing position the chain hangs vertically
in the line of the centre of the pivot F just touching the pulley P. To the shaft of
the pulley P may be applied ratchets and pawls with brake and manipulating gear as
above described, with reference to Fig. 1.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed I declare that what I claim is :-
:-
1. For a Moncrieff disappearing gun carriage having curved rolling elevators,
attaching counterweights to these elevators by flexible connections in such manner that
when the gun is in firing position the effect of the counterweights in resisting recoil is
nil or nearly so, but that it increases as the recoil movement proceeds, substantially as
described with reference to Fig 1.
2. For a Moncrieff disappearing gun carriage having lever arms which carry the
gun and rock on a cross shaft, attaching to these arms curved arms on which are
.wound cords, chains or bands suspending counterweights attached, in such manner
that when the gun is in firing position the effect of the counterweights in resisting
recoil is nil or nearly so, but that it increases as the recoil movement proceeds
substantially as described with reference to Fig. 2.
3. In combination with pullies worked by counterweights applied to disappearing
gun carriages in the manner referred to in the preceding claims, ratchets and pawls
with brake and manipulating gear arranged and operating substantially as described
with reference to Figs. 1, 14 and 1B.
ABEL & IMRAY,
Agents for the Applicant.