Improvements in Breech Mechanism for Breech-loading Ordnance,
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in Breech Mechanism for Breech-loading Ordnance,
We, ARTHUR TREVOR DAWSON, Superintendent of Ordnance Works, and
GEORGE THOMAS BUCKHAM, Engineer, both of Messrs. Vickers, Sons & Maxim,
Limited, of No. 28, Victoria Street, Westminster, in the County of London, do
hereby declare the nature of this invention to be as follows:
Our invention relates to mechanism for opening and closing the breech of
a breech loading gun and to a safety arrangement, for the firing gear combined
therewith. The breech mechanism to which our invention is applied is of the
kind in which the breech of the gun is closed by a screw plug which has inter-
rupted or segmental threads or rings, and is locked or unlocked by a partial
rotation on its axis.
This plug is carried on a swinging arm or carrier which is hinged to one side,
at the breech of the gun, and is, moved by a hand lever or by worm gear worked
by hand.
The form of obturator which we employ is such that the breech plug can be
swung out of the gun without any longitudinal withdrawal directly after it is
unlocked.
We shall describe our invention referring to the accompanying drawings.
Fig. 1 is a front view and Fig. 2 is a plan of the carrier and breech mechanism.
Fig. 3 is a part section on the line 3-3 of Fig. 2 and Fig. 4 is an elevation
of part of the breech of the gun with the plug and carrier in section.
A is the carrier and B the breech plug which are shewn in the open position
by the dotted lines A B in Fig. 2 the carrier swinging on its hinge pin C.
On this pin about midway of its height we fix a toothed segment D which gears
with a segment of a pinion E, pivotted in a recess in the carrier.
Part of the periphery of the pinion E has skew teeth gearing with similar
teeth on a pinion F, which is also pivotted in a recess of the carrier so that
it can revolve in a plane parallel to the breech face of the gun. From the
pinion F projects a short arm G having a pin f connected by a link H to a
pin b, projecting rearwards from the face of the breech plug. The link H and
the short arm G are so arranged as to be in a nearly straight line when the
breech is locked, the pin f being then somewhat past the dead centre and
the link H bearing against the upper side of the recess of the carrier in which
the parts are accommodated. Thus when the breech is closed the breech plug is
locked against any tendency to become unlocked by the shock of the explosion.
The hinge pin C, on which the carrier A, is fixed may be rotated by hand
or by worm gear K, as shewn.
.
When the firing gear L is of the kind described in the Specification to Patent
No. 10606 of 1896 the nut and slide are so arranged that the slide instead of
moving vertically down to cock the firing pin for safety it is moved horizontally
towards the pivot of the carrier. In order to effect this movement we employ
a connecting bar M sliding in a groove on the rear face of the carrier A and
having its one end connected to the slide of the firing gear by a spring pin m

page_text: and at its other end there is a second spring pin n which projects forward into
the recess in the carrier in which the pinion F is pivotted so as to enter a
cam slot N formed in the rear part of the arm G. This cam slot is so formed
as to give the connecting bar M a very quick motion towards the pivot of the
carrier during the first part of the movement of the arm G, before the breech
plug is unlocked that is before the pin f has moved back beyond the dead
centre.
This ensures that the charge cannot be fired except when the breech plug is
locked in the gun.
By the continued movement the cam slot N moves the connecting bar M of
the firing gear still further towards the side of the gun causing automatic
ejection of the fired primer as described in the Specification No. 10606 of 1896
above referred to.
The pins m and are held engaged by springs but can be drawn back by
hand when it is desired to remove the firing gear.
Dated this 27th day of October 1898
ABEL & IMRAY,
Agents for the Applicants.
We, ARTHUR TREVOR DAWSON, Superintendent of Ordnance Works, and
GEORGE THOMAS BUCKHAM, Engineer, both of Messrs. Vickers, Sons, & Maxim,
Limited, of 28, Victoria Street, Westminster, in the County of London, 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:-
Our invention relates to mechanism for opening and closing the breech of
a breech loading gun and to a safety arrangement for the firing gear combined
therewith. The breech mechanism to which our invention is applied is of the
kind in which the breech of the gun is closed by a screw plug which has inter-
rupted or segmental threads or rings, and is locked or unlocked by a partial
rotation on its axis.
This plug is carried on a swinging arm or carrier which is hinged to one side,
at the breech of the gun, and is, moved by a hand lever or by worm gear worked
by hand.
The form of obturator which we employ is such that the breech plug can be
swung out of the gun without any longitudinal withdrawal directly after it is
unlocked.
We shall describe our invention referring to the drawings accompanying our
Provisional Specification.
Fig. 1 is a front view and Fig. 2 is a plan of the carrier and breech mechanism.
Fig. 3 is a part section on the line 33 of Fig. 2 and Fig. 4 is an elevation
of part of the breech of the gun with the plug and carrier in section.
A is the carrier and B the breech plug which are sliewn in the open position
by the dotted lines A B in Fig. 2 the carrier swinging on its hinge pin C.
On this pin about midway of its height we fix a toothed segment D which gears
with a segment of a pinion E, pivotted in a recess in the carrier.
Part of the periphery of the pinion E has skew teeth gearing with similar
teeth on a pinion F, which is also pivotted in a recess of the carrier so that
it can revolve in a plane parallel to the breech face of the gun. From the

page_text: pinion projects a short arm G having a pin f connected by a link H to a
pin b, projecting rearwards from the face of the breech plug. The link H and
the short arm G are so arranged as to be in a nearly straight line when the
breech is locked, the pin f being then somewhat past the dead centre and
the link H bearing against the upper side h of the recess of the carrier in which
the parts are accommodated. Thus when the breech is closed the breech plug is
locked against any tendency to become unlocked by the shock of the explosion.
The hinge pin C, on which the carrier A, is fixed may be rotated by hand
or by worm gear K, as shewn.
When the firing gear L is of the kind described in the Specification to Patent
No. 10606 of 1896, the nut and slide are so arranged that the slide instead of
moving vertically down to cock the firing pin for safety it is moved horizontally
towards the pivot of the carrier. In order to effect this movement we employ
a connecting bar M sliding in a groove on the rear face of the carrier A and
having its one end connected to the slide of the firing gear by a spring pin m
and at its other end there is a second spring pin n which projects forward into
the recess in the carrier in which the pinion F is pivotted so as to enter a
cam slot N formed in the rear part of the arm G. This cam slot is so formed
as to give the connecting bar M a very quick motion towards the pivot of the
carrier during the first part of the movement of the arm G, before the breech
plug is unlocked that is before the pin f has moved back beyond the dead
centre.
This ensures that the charge cannot be fired except when the breech plug is
locked in the gun.
By the continued movement the cam slot N moves the connecting bar M of
the firing gear still further towards the side of the gun causing automatic
ejection of the fired primer as described in the Specification No. 10606 of 1896
above referred to.
The pins m and n are held engaged by springs but can be drawn back by
hand when it is desired to remove the firing gear.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we declare that what
we claim is:-
1. In breech mechanism for breech loading ordnance, in combination with
the carrier of the breech plug and its hinged pin, a toothed segment on the pin
gearing with a segment of a pinion pivotted in a recess of the carrier, this
pinion having a skew toothed segment gearing with a segment of another pinion
which has a short arm linked to a pin projecting rearward from the breech
plug the short arm and link forming a toggle which is just past its dead centre
when the breech plug is locked substantially as described.
2. In combination with the short arm above referred to a cam slot engaged
by a pin on a horizontal connecting bar connected by a pin to the firing gear
substantially as described.
1000