Improvements in the Breech Mechanism of Guns.
Year: 1895

page_text: Date of Application, 27th Apr, 1895 ..
Complete Specification Left, 25th Jan., 1896-Accepted, 29th Feb, 1896
PROVISIONAL SPECIFICATION.
Improvements in the Breech Mechanism of Guns.
1, AXEL WELIN, of 9 London Street, in the City of London, Mechanical
Engineer, do hereby declare the nature of this invention to be as follows:-
--
In guns, especially those of the quick-firing type, it is often desirable that the
breech block should be withdrawn by simply swinging it about a pivot. In order
to enable this to be done the breech block has in some cases been made conical.
This method however as hitherto carried out has involved the weakening of the
divided screws by which the block is secured in the breech because owing to the
conical form of the breech and block the slope at the rear of each thread in the gun
and the front of each thread on the block is longer than the other slope and
the difference between these lengths represents metal' which presents no resistance
to a sheering strain in other words if the breech block were blown out the total
width of the metal shorn away from the top of the threads of the screws in the gun
and on the block would be less than the length of the threaded part of the breech
block.
According to this invention I obviate this objection by modifying the screws
causing the rear face of each thread in the gun and the front face of each thread on"
the block in place of being sloped as heretofore to be generated by a line at
right angles to the axis of the gun and block the other faces being sloped
as before.
It will be obvious that by simply making the one slope steeper than the other,
part of the advantage gained by this invention would be attained..
Dated this 27th day of April 1895.
ՎԱԼՍԱՄԱՆԵՂԾ ԵԶԵԵՆ ԱՂԵՍՈՒԱՐԱՄ 0 ցած
I, AXEL WELIN of 9 London Street, in the City of London, Mechanical
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 :-
In guns, especially those of the quick firing type, it is often desirable that the
breech block should be withdrawn by simply swinging it about a pivot. In order
to enable this to be done the breech block has in some cases been made tapered or
conical. This method however as hitherto carried out has involved the weakening
of the divided screws by which the block is secured in the breach because owing to
the conical form of the breach and block the slope at the rear of each thread in the
gun and the front of each thread on the block is longer than the other slope and
the difference between these lengths represents metal which presents no resistance
to a shearing strain-in other words if the breech block were blown out the total
width of the metal shorn away from the top of the threads of the screws in the gun
and on the block would be less than the length of the threaded part of the breech
block.

page_text: According to this invention I obviate this objection by modifying the screws
causing the rear face of each thread in the gun and the front face of each thread on
the block in place of being sloped as heretofore to be generated by a line at right
angles to the axis of the gun and block the other faces being sloped as before.
Figure 1 is a longitudinal section of part of a breech block and gun with
the screw threads made in the ordinary way. Figure 2 is a similar view illustrating
my invention.
In these figures.a is the gun and b. the breech block.
It will be seen that the breech block, Figure 1, could be blown out by shearing
away a length of metal equal to B.C. +DE+ FG+HII which is less than that of
the threaded part of the breech block by AB + CD + EF + GH IJ whereas
in the arrangement shewn in Figure 2 the breech block could only be blown out by
shearing away a length of metal equal to the length of the threaded part of the
breech block.
It will be obvious that by simply making the one slope. steeper than the other,
part of the advantage gained by this invention would be attained..
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 combination of a tapering breech block, a corresponding breech opening,
a divided screw on the block such that the front face of each of the threads makes
a greater angle with the axis of the block than the rear face, and a corresponding
screw in the breech.
2. The combination of a tapering breech block, a corresponding breech opening,
a divided screw on the block having the front face of each of its threads at right
angles to the axis of the block and the rear face inclined thereto and a corresponding
screw. in the breech.
Dated this thth dan İn
1004
AXEL WELIN.