Improvements in Breech Mechanism for Ordnance.
Year: 1888

page_text: Date of Application, 11th Oct., 1888
Complete Specification Left, 9th July, 1889-Accepted; 10th Aug.,
1889
PROVISIONAL SPECIFICATION.
Improvements in Breech Mechanism for Ordnance.
I, JOHN FIELDING of the Atlas Works in the city and County of Gloucester
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention refers to breech loading ordnance in which the breech block is
secured by means of an interrupted screw thread formed on the exterior of the block
and in the interior of breech of gun, on what is known as the French system, the
block when withdrawn being carried in a tray or ring hinged to the Gun for the
purpose of swinging the block clear of the breech to allow of the loading 'of
the gun.
In order to open the breech it is first necessary to turn the block far enough to
disengage the threads and bring those on the block opposite the spaces in the breech
thread, it is then drawn straight out until it can be swung out of the way in the hinged
tray or ring.
According to this invention these three movements are performed by turning a
winch handle continuously in the same direction from the commencement of the first
until the completion of the last movement, and the reverse movement of the handle
causes the block to be replaced and secured.
The construction by which this result is obtained is as follows, viz. :-
The winch handle is formed or keyed on a shaft working in a bole bored
eccentrically in the breech block, parallel with the axis and opposite or in line with
the centre of one of the threaded parts of the block.
On the shaft also are keyed or formed a short segment of a spur pinion, and a
worm. The segment when the block is "home" gears with a short internal segment.
on the hinge box of tray or ring. The worm when the breech block is turned so as to
bring its threads opposite the spaces in breech, gears with a suitable worm rack cut
in one of the said spaces.
The worm rack is continued from the rear of the breech for a distance around
the hinge boss on rear of gun, the teeth on the latter forming a segment of a worm
wheel.
The block is removed in the following manner viz. :—
The first movement of the winch handle unscrews the block by means of the
pinion segment gearing with internal segment, at the same time the worm is brought
into gear with the rack and the continued rotation of the winch handle withdraws
the block far enough to enable it to be swung clear away which is done by the further
rotation of the handle.
I
In lieu of a spur pinion and segment for unscrewing the block, a finger on the
winch shaft may engage in a slot formed on the tray or ring.
By a slight inodification, the block, instead of being swung away from the breech
in the manner described above may be traversed across the rear face of gun, either
in a straight line or around a pivot fixed to the rear of the gun parallel with its axis,
a.spur pinion on the winch shaft gearing into a straight or segmental rack, the block
resting in a tray or guide working in suitable slide or upon the pivot.
In lieu of the shaft being turned manually by the winch handle, it may be driven
by a hydraulic, steam, air, electric, or other motor.
JOHN FIELDING

page_text: COMPLETE SPECIFICATION.
Improvements in Breech Mechanism for Ordnance.
.I, JOHN FIELDING of the Atlas Works in the City of Gloucester, Engineer 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
.
This invention refers to breech loading ordnance in which the breech block is
secured by means of an interrupted screw thread formed on the exterior of the block
and in the interior of breech of gun, on what is known as the French system, the
block when withdrawn being carried in a tray or ring hinged to the gun for the
purpose of swinging the block clear of the breech to allow of the loading of
the gun.
In order to open the breech, it is first necessary to turn the block far enough to
disengage the threads and bring those on the block opposite the spaces in the breech
thread, it is then drawn straight out until it can be swung out of the way in the
hinged tray or ring.
According to this invention these three movements are performed by turning a
winch handle continuously in the same direction from the commencement of the first
until the completion of the last movement, and the reverse movement of the handle
causes the block to be replaced and secured.
The construction by which this result is obtained is as follows, viz. :—
The winch handle is formed or keyed on a shaft working in a hole bored eccentrically
in the breech block, parallel with the axis and opposite or in line with the centre of
one of the threaded parts of the block.
23
On the shaft also are keyed or formed a short segment of a spur pinion, and a
worm. The segment when the block is "home gears with a short internal segment
on the hinge box of tray or ring. The worm when the breech block is turned so as
to bring its threads opposite the spaces in breech, gears with à suitable worm rack cut
in one of the said spaces.
The worm rack is continued from the rear of the breech for a distance around the
hinge boss on rear of gun, the teeth on the latter forming a segment of a worm
wheel.
The block is removed in the following manner, viz. :—
The first movement of the winch handle unscrews the block by means of the
pinion segment gearing with internal segment, at the same time the worm is brought
into gear with the rack and the continued rotation of the winch handle, withdraws
the block far enough to enable it to be swung clear away, which is done by the further
. rotation of the handle.
In lieu of a spur pinion and segment for unscrewing the block, a finger on the
winch shaft may engage in a slot formed on the tray or ring.
By a slight modification the block instead of being swung away from the breech
in the manner described above, may be traversed across the rear face of
gun, either
in a straight line or around a pivot fixed to the rear of the gun, parallel with its
axis, a spur pinion on the winch shaft gearing into a straight segmental rack, the
block resting in a tray or guide working in suitable slide or upon the pivot.
In lieu of the shaft being turned manually by the winch handle, it may be driven
.by.a. hydraulic, steam, air, electric, or other motor.
DESCRIPTION OF THE DRAWINGS.
Fig. 1. is an end elevation of the breech of the gun, the block being secured ready
for firing.
Fig. 2. is a horizontal section of the same.
Fig. 3. is similar to Fig. 1. except that the block is unlocked.
Fig. 4. is a horizontal section of Fig. 3. the dotted lines shew the block home, the

page_text: Fig. 5. is a horizontal section similar to Fig. 4. but with the block swung clear for
loading.
Fig. 6. is a cross section of gun through the breech thread and helical rack.
Referring to the various figures on this drawing, A. is the gun, B the breech
block C. the block ring, D. the hinge plate on which C. is pivotted, E is a shaft
carrying a winch handle F. on the boss of which is cut a segment of a pinion G,
gearing with another segment H, fixed on block ring C. The shaft E. also carries
a quick pitched worm I. gearing when the block is unlocked with a helical rack J,
cut in one of the spaces between the threads in breech of gun. The rack J. is
continued beyond the breech through the hinge plate D. and also some distance
around the hinge boss on which it forms a segment of a worm wheel.
The breech is opened in the following manner, viz. :-The handle F is turned from
the position shewn in Fig. 1. to that shewn in Fig. 3 which causes the segment G to
work in H. unlocking the block, the unlocking of block brings the worm I. into gear
with rack J. and the continued rotation of the shaft E. draws the block first straight
out into the position shewn by full lines in Fig. 4. and then into the angular
position shewn on Fig. 5.
The rotation of the shaft E in the reverse direction first replaces the block, and then
locks it.
In order to ensure the proper sequence of the sliding and swinging movements of
the breech block a catch bolt may be fitted to the block ring C, and breech plate D
in the manner shewn in Sauvee's specification-No. 9813 of 1887 or any suitable
equivalent arrangement.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. The construction and use of apparatus for working the breech blocks of breech
loading ordnance, substantially as herein described in reference to the accompanying
drawings.
2. In combination with breech block B block ring and hinge plate D, the use of
a shaft E carrying worm I and toothed segment or finger G, working respectively
in rack J and segment or slot H, arranged and operating substantially as described.
Dated this 8th day of July 1889.
JOHN FIELDING.