Improvements in the Breech Closing Mechanism of Ordnance.
Year: 1890

page_text: Date of Application, 31st Oct., 1890
Complete Specification Left, 29th July, 1891-Accepted, 29th Aug.,
1891
PROVISIONAL SPECIFICATION.
Improvements in the Breech Closing Mechanism of Ordnance.
I, HENRI SCHNEIDER of Le Creusot in the Republic of France, Manufacturer,
do hereby declare the nature of this invention to be as follows:--
In heavy ordnance the operations of opening and closing the breech by hand
present great difficulties owing to the great weight of the parts to be moved.
By means of my invention the breech of a piece of ordnance is enabled to be
opened or closed with great facility by means of a continuous rotary movement
obtained as hereinafter explained.
The breech screw has interrupted threads which engage with corresponding
threads in the chamber in the usual manner and when disengaged from the breech
is supported by a swinging bracket.
A bar provided with two toothed racks slides in an undercut groove in the
breech face. One of the racks gears with a pinion on a vertical shaft forming the
pivot of the hinge of the bracket and the other gears with a toothed quadrant on
the breech screw.
Another pinion or quadrant of larger diameter is likewise
keyed on the same vertical shaft at such an angle that when the small pinion quits
its rack the quadrant or lower pinion engages with a horizontal rack in the side of
the breech screw.
In order to ensure the correct re-engagement of the teeth when the movement
of the pinion is reversed one tooth of the pinion is prolonged and acts as a stop.
The breech is opened by causing the vertical hinge shaft carrying the pinion and
quadrant to partake of a continuous rotary motion and the breech is closed by
rotating the said shaft in the opposite direction. In guns of large size this rotation
is preferably obtained by means of a crank handle on a horizontal shaft carrying
an endless screw or worm driving a worm wheel on the said vertical shaft.
To open the breech the crank handle is rotated and this movement is transmitted
to the vertical shaft or pivot of the hinge by the intervention of the worm and
worm wheel. The vertical shaft causes the pinion and quadrant to rotate the
pinion drives the horizontal rack bar and thereby causes the breech screw to
describe one sixth of a revolution. When the sixth of a revolution is completed
the interrupted screw threads are disengaged the pinion quits its rack and the lower
pinion or quadrant which up to this moment has rotated without gearing with its
rack comes opposite to the teeth of the horizontal rack on the breech screw.
"
The rotation of the vertical hinge shaft continuing, the quadrant exerts force
upon this rack and draws the breech screw out of its chamber. During this period
the cylindrical part of the pinion engages with a corresponding hollow formed in
the rack bar so that the latter is rendered immovable during the following
operations. The breech screw being moved completely out of its chamber rests
upon projections on the claws of the bracket, at this moment the bracket which
was previously rigidly connected to the gun barrel by a vertical bolt engaging with
a catch or scar becomes free, this bolt being pushed up by means of an incline on
its lower end and the upper end being capable of entering a suitable recess in the
underside of the breech screw.
The force of rotation of the quadrant on the vertical hinge shaft is transmitted
to the bracket and directly this rotation commences the bolt rises and locks the
breech screw to the bracket; at the same time a horizontal bolt acted on by a
spring retains the vertical bolt in position by means of inclined projections on the
one bolt engaging with corresponding recesses in the other. This prevents the
return of the breech screw into its chamber until the horizontal bolt has been

page_text: to IES place by coming in contact with the rear face of the breech and
thereby depressing the vertical bolt. The continuous movement of rotation of the
vertical hinge shaft is converted by the action of the pinion and quadrant into two
reciprocating rectilinear movements of the racks one of which produces the engage-
ment or disengagement of the interrupted screw threads the other producing the
removal of the breech screw and also into a movement of rotation causing the
bracket and the screw to oscillate upon the hinge in order to clear the opening of
the breech.
Dated this 31st day of October 1890
J. H. JOHNSON & Co..
47, Lincoln's Inn Fields, London, Agents.
COMPLETE SPECIFICATION.
Improvements in the Breech Closing Mechanism of Ordnance.
I HENRI SCHNEIDER Le Creusot in the Republic of France Manufacturer 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 relates to improvements in the breech closing mechanism of
ordnance. In heavy ordnance the operations of opening and closing the breech by
hand present great difficulties owing to the great weight of the parts to be moved.
The improved breech closing mechanism constructed according to this invention
enables the breech of a piece of ordnance to be opened or closed with great facility
by means of a continuous rotary movement applied as hereinafter described.
And in order that my said invention may be fully understood I shall now proceed
more particularly to describe the same and for that purpose shall refer to the several
figures on the annexed sheets of drawings the same letters of reference indicating
corresponding parts in all the figures.
Figure 1 of the accompanying drawings represents the mechanism in vertical
section.
Figure 2 is a front elevation of the same.
Figure 3 represents a part of the breech in a horizontal section taken through
the axis of the barrel and
Figure 4 represents the mechanism in plan.
In this mechanism a breech screw 1 is provided with interrupted threads which
engage with corresponding threads in the chamber or breech 2 in the usual manner.
When disengaged from the breech this screw is supported by a swinging support
or bracket 3. The breech mechanism is constructed with two racks A and J
placed at right angles to one another (Figure 4) and worked by two pinions Band D
of different diameters keyed upon a vertical shaft E forming the axis of oscillation
of the breech block support 3.
The upper rack A is provided with vertical teeth A' gearing with the pinion B
and slides in a horizontal groove or guide way cut in the face of the breech. This
rack is further provided with horizontal teeth A gearing with a toothed segment C
on the breech screw bearing such a proportion to the driving pinion Bas
in order to enable the movement of the support 3 to produce one sixth of a
necessary
revolution of the breech block for the purpose of releasing the threads of the
breech screw.
The lower pinion D which drives the straight rack J is provided with teeth for
about one half of a circle only and produces the rectilinear movement required for
withdrawing the breech block from the breech. This pinion or toothed segment D
is keyed upon the shaft E at such an angle relatively to the racks that when the 5
pinion B goes out of gear with the rack teeth A' the lower pinion D or segment D
goes into gear with the second rack J the teeth of which are cut in the side of the
breech screw as represented in Figure 3.

page_text: When the breech is closed it can be opened by rotating the crank handle F cou-
tinuously in one direction. This movement is transmitted to the shaft E or pivot
of the hinge by the action of the shaft H' worm H and worm wheel I. By these
means rotary motion is transmitted to the pinions B and D the pinion B first moves
the rack A in such a manner as to cause the rack teeth A2 to act upon the toothed
sector C and cause the breech screw 1 to describe one sixth of a revolution for the
purpose of disengaging the screw threads. When this fraction of a revolution is
completed (Fig. 4) the pinion B runs out of gear with the rack A and the lower
pinion or segment D which up to this moment has rotated without acting on the
rack J now engages with the teeth of the said rack.
The rotation of the hinge shaft E continuing the action of the segment D upon
the rack J compels the breech block to retire or move out of its chamber.
During this period the cylindrical part m n of the upper pinion B engages with a
corresponding concave or recess op formed in the rack A so that the latter is
rendered immovable relatively to the breech block support during the period
occupied by the subsequent operations. The breech block being moved completely
out of its chamber rests upon the projections K on the swinging support or bracket
and at the same time the bracket or support which up to this point is rigidly
connected to the breech by a bolt L Fig. I engaging with a catch M becomes free
as the breech block in moving out of the breech presents a recess 5 over the bolt L
so as to enable it to be pushed up by the action of an incline acted on by a corre-
sponding incline on the catch M. At the same time the upper end of the bolt L
enters the recess 5 in the underside of the breech block and locks the latter to the
bracket. The rotary movement of the toothed segment D is then transmitted to
the bracket and at the same time a horizontal bolt P acted on by a spring N retains
the vertical bolt 1 in position by means of inclined slots engaging with corre-
sponding projections r on the vertical bolt L. By these means the breech screw is
prevented from returning into its chamber when the movement of the support is
reversed until after the bolt P has been returned to its original position (as
represented in Figure 1) by coming in contact with the rear face of the breech
and thereby depressing the vertical bolt L. The continuous movement of rotation
of the hinge shaft E is thus converted by the action of the pinion and toothed
segment into two reciprocating rectilinear movements one of which produces the
engagement or disengagement of the screw threads in the breech the other pro-
ducing the withdrawal of the breech screw a movement of rotation being also
obtained, causing the bracket and the breech block to swing together upon the hinge
shaft E in order to clear the opening of the breech.
The materials proportions forms and dimensions as well as the accessory arrange-
ments hereinbefore described may evidently be modified according to circumstances
without affecting the spirit of the invention.

page_text: Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. In a breech closing mechanism for ordnance the combination of a rack A
sliding in the face of the breech and transmitting a rotary movement to a breech
block provided with a toothed sector C, and a rack J attached to the breech block
and transmitting a rectilinear movement to the said block the said racks receiving
motion respectively from a pinion B and a pinion or segment D, fixed on a shaft E
forming the pivot or axis of oscillation of the bracket which receives the breech
block when disengaged from the breech the movements necessary for opening or
closing the breech being obtained by a continuous rotary motion of the said shaft
substantially as hereinbefore described with reference to the accompanying
drawings.
2. In combination with the mechanism formed by the combination of the two
racks A. and J and the two pinions B and D carried by a common shaft E the
arrangement of the bolt L serving to lock the breech block on the bracket when
withdrawn from the breech the said bolt being itself retained or locked in turn by
a bolt P whilst the breech block swings upon the shaft forming the hinge of the
supporting bracket all operating in. the manner substantially as hereinbefore
described with reference to the accompanying drawing.
3. The combination of a breech closing mechanism for ordnance comprising
two racks A and J, two pinions B and D placed upon a common shaft E and two
locking bolts L and P as hereinbefore described and claimed with means for
operating the said mechanism consisting of a worm wheel I receiving motion from
a worm H fixed on a shaft H provided with a crank handle F all substantially as
and for the purpose hereinbefore explained with reference to the accompanying
drawing.
4. The arrangements and combinations of parts constituting the improvements
in breech closing mechanism of ordnance substantially as hereinbefore described
with reference to the accompanying drawings.
Dated this 29th day of July 1891.
J. H. JOHNSON & Co.,
Agents.