Improvements in Hydraulic Recoil-brakes for Ordnance and the like.
Year: 1887

page_text: Date of Application, 15th Nov., 1887
Complete Specification Left, 21st July, 1888
Complete Specification Accepted, 31st Aug., 1888
PROVISIONAL SPECIFICATION.
Improvements in Hydraulic Recoil-brakes for Ordnance and the
like.
I, OTTO KRELL of 11 Quai der Grand Neiva St. Petersburg, Russia, director of
the St. Petersburger Metallwaaren Fabrik, do hereby declare the nature of this
invention to be as follows:-
This invention relates to a hydraulic recoil-brake for ordnance and the like, that
can be worked by a single cylinder, or by two cylinders acting independently of each
other, and that is so arranged that the sectional area of the passage for the fluid is
automatically varied according to the required uniform decrease of the recoil motion,
while the return motion may be effected in any desired predetermined manner.
Fig. 1 of the accompanying drawings shews the general arrangement of a gun
carriage in which the gun rests with its trunnions in brackets formed on the hydraulic
cylinder a, or two independent cylinders a, so that the cylinder moves backward and
forward with the gun. The cylinder is guided by a fixed piston rod n and piston
having channels through it for the passage of liquid. The arrangement of these
parts may however also be reversed, the cylinder being fixed, and the piston and
piston rod made to move with the gun. Figs. 2 and 3 shew respectively a vertical
and a horizontal part, longitudinal section through the hydraulic cylinder, Fig. 4
shews the arrangement for the automatic regulation of the valve i that controls the
running out motion; Figs. 5 and 6 shew the mechanism for the valve i in the closed
and open positions, as also the regulation thereof by hand by means of a lever on
the gun carriage, Fig. 1; Figs. 7 and 8 shew two cross sections through the cylinder
on lines 2-2 and 1-1 Fig. 2. Figs. 9 and 10 are two cross sections on line 3-3
and 4-4 Fig. 4; Fig. 11 shews the opening in the piston and the annular slide
therein, for a particular case.
The hydraulic cylinder a has at each end a stuffing box through which passes the
piston rod n of uniform diameter, so that the cylinder, which is filled entirely with
liquid, is perfectly closed.
The piston rod n has a piston which has openings c and passages e for the passage
of the liquid from one side of the piston to the other.

page_text: On firing the gun the hydraulic brako-cylinder a is driven backward by the recoil,
and consequently forces the liquid in front of the piston to pass through the openings c
and passages e of the latter into the back end.
The openings c are controlled by means of an annular slide d capable of revolving
upon the piston but prevented from shifting longitudinally thereon. The ring-slide d
has openings the form of which is shewn by way of example, for a particular case,
at Fig. 11, and the partial rotation of the slide so as to bring these openings into the
required positions relatively to the openings c of the piston is effected by means of
helical grooves formed in the sides of the cylinder, into which the studs g on the
slide enter; so that as the cylinder moves to and fro, the slide is turned alternately in
opposite directions. The openings are so formed, that as the cylinder is moved
backward by the recoil, the openings c of the piston are gradually more and more
restricted by the slide, and are entirely closed when such backward motion is com-
pleted, so that by this means a uniform resistance is opposed to the recoil, causing a
uniforin decrease in the speed thereof in such manner that its extent can be accurately
determined.
During the recoil a valve i situated in the piston & between the inlet openings c for
the liquid and the passages e through which the liquid issues, is opened automatically
by the pressure of the liquid against the weaker pressure of the spring k acting on
the outer end of the valve stem and tending to close the valve.
At the end of the recoil the valve is closed by its spring and would, if entirely
closed prevent the running forward of the gun. But if the complete closing of the
valve is prevented by an adjusting device such as, for example, the screw nuts m on
the valve stem as shewn in Fig. 4, which are arranged to bear against a seating c
before the valve i closes, the running forward of the gun will take place at a speed
determined by the extent to which the valve i is kept open.
If two independent hydraulic brake cylinders are employed, the piston of one of
these cylinders may be provided with the above described automatic arrangement for
permitting the running forward of the gun, while the piston valve i of the second
cylinder is controlled by a lever 7 on the gun carriage as shewn at Figs. 1, 5, and 6 so
that according to the position of this lever, the valve i is either left perfectly free to
close entirely, or it may be held completely open.
In the first case, the running forward cannot commence, notwithstanding that the
valve of the first cylinder is not completely closed, because such motion is effectually
prevented by the complete closure of the valve of the second cylinder. In the second
case, the running forward will take place at a speed determined by the opening of
the first valve although the second valve is completely open. Thus by moving the
lever of the second valve, into the one position or the other, the gun may either be
made to run forward automatically or be held in the backward position.
If the gun be kept for some time in the backward position a certain, though it may
be only slight, forward motion of the gun might be caused by leakage through the
closed valve or past the pistons. In order to prevent this, there is provided on the
gun carriage a spring catch or pawl Z that takes into notches in the hydraulic cylinder
when in the backward position; the said pawl being connected by rods with the
lever in such a manner as to be drawn out of gear with the cylinder notches thereby
when the lever is in position for allowing the automatic forward motion of the gun.
The connection of the pawl with the lever is effected through the medium of a
spring k¹, so that it can be drawn out of gear independently of the lever for per-
mitting the running forward of the gun.
Dated this 15th day of November 1887.
ABEL & IMRAY,
Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in Hydraulic Recoil Brakes for Ordnance and the
like.
I, OTTO KRELL of 11 Quai der Grand Neiva, St. Petersburg, Russia, director of
the St. Petersburger Metallwaaren Fabrik, do hereby declare the nature of this inven-
tion 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 a hydraulic recoil brake for ordnance and the like, that
can be worked by a single cylinder, or by two cylinders acting independently of each
other and that is so arranged that the sectional area of the passage for the fluid is
automatically varied according to the required uniform decrease of the recoil motion
while the return motion may be effected in any desired predetermined manner.
shew
Fig. 1 of the drawings accompanying my Provisional Specification shews the
general arrangement of a gun carriage in which the gun rests with its trunnions in
brackets formed on the hydraulic cylinder a or two independent cylinders a so that
the cylinder moves backward and forward with the gun. The cylinder is guided by
a fixed piston rod n and piston having channels through it for the passage of liquid.
The arrangement of these parts may however also be reversed, the cylinder being
fixed, and the piston and piston rod made to move with the gun. Figs. 2 and
respectively a vertical and a horizontal part longitudinal section through the hydraulic
cylinder. Fig. 4 shews the arrangement for the automatic regulation of the valve i
that controlls the running out motion; Figs. 5 and 6 shew the mechanism for the
valve i in the closed and open positions as also the regulation thereof by hand by
means of a lever on the gun carriage Fig. 1. Figs. 7 and 8 shew two cross sections
through the cylinder on lines 2-2 and 1-1 Fig. 2. Figs. 9 and 10 are two cross
sections on line 3-3 and 4-4 Fig. 4; Fig. 11 shews the opening in the piston and
the annular slide therein, for a particular case.
The hydraulic cylinder a has at each end a stuffing box through which passes the
piston rod n of uniform diameter, so that the cylinder which is filled entirely with
liquid is perfectly closed.
The piston rod n has a piston b which has openings e and passages e for the passage
of the liquid from one side of the piston to the other.
On firing the gun the hydraulic brake cylinder a is driven backward by the recoil,
and consequently forces the liquid in front of the piston to pass through the openings c
and passages e of the latter into the back end.
The openings c are controlled by means of an annular slide d capable of revolving
upon the piston but prevented from shifting longitudinally thereon. The ring slide.d
has openings / the form of which is shewn by way of example for a particular case,
at Fig. 11, and the partial rotation of the slide so as to bring these openings into the
required positions relatively to the openings c of the piston is effected by means of

page_text: helical grooves formed in the sides of the cylinder into which the studs g on the
slide enter, so that as the cylinder moves to and fro the slide is turned alternately in
opposite directions. The openings h are so formed that as the cylinder is moved
backward by the recoil the openings e of the piston are gradually more and more
restricted by the slide, and are entirely closed when such backward motion is com-
pleted, so that by this means a uniform resistance is opposed to the recoil causing a
uniform decrease in the speed thereof in such manner that its extent can be accurately
determined.
During the recoil a valve i situated in the piston between the inlet openings c for
the liquid and the passages e through which the liquid issues is opened automatically
by the pressure of the liquid against the weaker pressure of the spring acting on
the outer end of the valve stem and tending to close the valve.
At the end of the recoil the valve is closed by its spring and would if entirely
closed prevent the running forward of the gun. But if the complete closing of the
valve is prevented by an adjusting device such as, for example the screw nuts m on
the valve stem as shewn in Fig. 4, which are arranged to bear against a seating
before the valve i closes, the running forward of the gun will take place at a speed
determined by the extent to which the valve i is kept open.
KC
If two independent hydraulic brake cylinders are employed the piston of one of
these cylinders may be provided with the above described automatic arrangement for
permitting the running forward of the gun while the piston valve i of the second
cylinder is controlled by a lever on the gun carriage as shewn at Figs. 1, 5 and 6 so
that according to the position of this lever, the valve i is either left perfectly free to
close entirely, or it may be held completely open.
In the first case the running forward cannot commence, notwithstanding that the
valve of the first cylinder is not completely closed, because such motion is effectually
prevented by the complete closure of the valve of the second cylinder. In the second
case, the running forward will take place at a speed determined by the opening of the
first valve, although the second valve is completely open. Thus by moving the lever
of the second valve, into the one position or the other, the gun may either be made
to run forward automatically or be held in the backward position.
If the gun be kept for some time in the backward position a certain, though it
may be only slight forward motion of the gun might be caused by leakage through
the closed valve or past the pistons. In order to prevent this, there is provided on
the gun carriage a spring catch or pawl Z that takes into notches in the hydraulic
cylinder when in the backward position; the said pawl being connected by rods with
the lever in such a manner as to be drawn out of gear with the cylinder notches
thereby when the lever is in position for allowing the automatic forward motion of
the gun. The connection of the pawl with the lever is effected through the medium
of a spring k¹, so that it can be drawn out of gear independently of the lever for
permitting the running forward of the gun.
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. A hydraulic recoil brake wherein the following devices are employed in com-
bination:
a, a piston 6 having a central passage through it and carrying an annular slide d
prevented from moving longitudinally thereon but capable of being rotated by
the action of lugs g working in grooves fin the cylinder, the said piston having
openings c corresponding to openings / in the slide.
b. a check valve i that closes automatically on the return motion of the piston
arranged between the openings c for the inlet of the liquid and openings e for
the outlet thereof, and capable of adjustment from the outside.
2. In recoil brake apparatus such as is referred to in the preceding claim, the
combination of two hydraulic cylinders in such manner that in the one cylinder the
check valve operates in the manner set forth in the preceding claim so as to allow
the running forward at a certain speed, while in the other cylinder the valve i is

page_text: opened or closed by a lever / so as either to allow the running forward at a speed
determined by the first named valve, or to hold the gun in the backward position
after recoil, substantially as herein described.
3. In combination with the lever of the second brake cylinder referred to in the
preceding claim, the use of a spring pawl or catch Z that holds the gun in the back-
ward position and is connected to the level 7 so as to release the gun when the valve i
is opened by the lever for allowing the forward motion substantially as herein
described.