Improvements in Hydraulic Brakes for Ordnance.
Year: 1890

page_text: Date of Application, 6th May, 1890-Accepted, 12th July. 1890
COMPLETE SPECIFICATION.
Improvements in Hydraulic Brakes for Ordnance.
I, ALFRED LONGSDON of 9 New Broad Street in the City of London, Civil
Engineer do hereby declare the nature of this invention (a communication to me
from abroad by the firm of Fried Krupp of Essen in the Empire of Germany, Cast
Steel Manufacturors) 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 improvements in the hydraulic brakes employed for
regulating the recoil and also for shifting forwards and backwards pieces of ordnance,
and consists in means for the attainment of a uniform resistance upon recoil, by the
introduction of a conical rod in the interior of the brake cylinder by which rod the
area or diameter of the passage or escapement from one side to the other of
the piston is correspondingly or proportionately diminished. With these brakes it
has hitherto been necessary upon firing that the fluid forced out of the brake cylinder
by the entrance of the piston rod should be withdrawn at the front end of the cylinder
in order that the contents of the cylinder might fully operate upon the brake. It
is however frequently desirable to withdraw the fluid at the back end of the cylinder,
and to attain this object I introduce into the brake cylinder a tube provided with an
escape valve, which has a variable exterior diameter or the same may also be replaced
by a cylindrical tube, having exterior conical grooves.
This invention will be readily understood by reference to the accompanying
drawings in which similar letters of reference refer to like parts in all the figures.
Figure 1 is a longitudinal section through the hydraulic brake cylindor, showing
its piston rod, a brake valve situated therein, and also an escape valve connected with
the regulating tube.
Figure 2 shews in section an arrangement with a circular brake valve and a
cylindrical tube formed with grooves.
Figure 3 shews in section an arrangement of the conical tube with escape valve in
which the piston is not provided with a brake valve.
Figure 4 represents in section a modification of the brake in which the tube has
inserted into it a conical rod which is fastened in the piston, and the escape valve is
provided with a counter-pressure cylinder.
The arrangement and the fixing of the foregoing brake to a piece of ordnance is
effected by the usual known method namely, that the top carriage is firmly connected
either with the piston or the brake cylinder whilst the respective other part of the
brake cylinder or piston is firmly fastened to the framework of the carriage; the
recoil of the piece of ordnance is received by the part of the brake that is movable
with the top carriage.
The piston rod A of the brake cylinder B represented in Figure 1 is bored so that
it may receive the regulating tube E which is fastened to the cover of the cylinder
and connected with the escape valve. The tube E is shaped conically on the
outside and variation of diameter is determined by calculation and according to
circumstances.
The escape valve consists of the valve L situated in the chamber Z and is kept
against its seat by a spring N. The cover of the brake cylinder is chamber-formed
for the purpose of receiving this valve and closed with a cover plate. The brake
valve C is of a tubular form and is kept against its seat by a spring D. The seat F
of this valve is situated in the body G of the piston which contains an annular
cavity which is in connection with the front portion of the brake cylinder by
apertures H.

page_text: Upon the discharge of the piece of ordnance the brake piston enters the cylinder,
when in consequence of the recoil, the brake valve in the piston is opened, the
connection between the two sides of the piston is effected and the liquid can flow
forwards from the back side of the piston whereupon the suctional area of the
outflow decreases in proportion to the increasing thickness or diameter of the conical
tube.
The fluid situated behind the piston passes through the continually decreasing area
of the outflow in the piston partly towards the front side of the piston and parily
(corresponding to the volume of the piston rod) through the regulating pipe E and
through the escape valve from the cylinder.
The entrance and exit of the pressure fluid upon the forward and backward move-
ment of the piece of ordnance is effected by means of tubular connections fitted to
parts O and P; the escape of the fluid forced out by the recoil is through tho
passage in the cover either into the waste pipe or if an accumulation of power is
intended during the recoil, into an accumulator.
In Figure 2 the elongated tubular brake valve is replaced by a circular valve Cand
the conical shaped tube by a cylindrical tube E with conical grooves. The action is
the same as in above described arrangement.
In the arrangement represented in Figure 3 the piston is without a brake valve.
The pressure fluid enters the cylinder through the passage way P and serves only for
the forward movement of the piston.
The escape valve connecting with the regulating pipe E may be provided_with_a
counter-pressure cylinder, when it is intended to diminish as much as possible the
initial pressure in the cylinder. This arrangement is represented in Figure 4. Tho
shaft of the valve L is connected with a piston K which is movable in a cylinder R.
At V is situated the connection pipe for the pressure fluid, which enters behind the
piston K as soon as the slide valve for the forward movement of the gun is opened.
The valve is thereby held closed because the piston K is of larger area than the
valve L. When the gun and the slide valve serving for the movement thereof are in
firing position by a suitable arrangement of this slide valvo the access of the pressure
fluid to the brake cylinder is cut off and at the same time the discharge of the pressure
fluid from the cylinder R through the passage V is effected so that the valve is loaded
by the spring N which only offers slight resistance to the opening of the said valve.
Instead of a tube as previously described for altering the area of the flow of fluid, u
tube E fastened in the bottom of the cylinder with a conical rod E' fixed into the
hollow piston rod and projecting into the tube may be applied as shown in Figure 4.
This arrangement permits the possibility of the rod being easily changed from the
outside which in some cases may be desirable.
The hereinbefore described improvements may be applied to guns of different
calibres and systems.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is :
First In hydraulic brakes for the regulation of the recoil as also for the forward
and backward movement of a piece of ordnanco, in which the brake piston G or
brake cylinder B is firmly fastened to the top carriage, the arrangement of a tubo E
of varying exterior diameter fixed in the bottom of the cylinder which tube entering
into the hollow piston rod A upon the recoil diminishes the sectional area of the
passage for the flow of fluid and carries away the fluid forced out of the cylinder by
the entrance of the piston rod as set forth.
Second: In hydraulic brakes for ordnance the combination of the tube E as claimed
in claim 1, with a spring loaded escape valvo Z or with counter-prossure cylinder and
spring loaded escape valve as set forth.
Third: In hydraulic brakes for ordnance instead of the tubo E as claimed in
claim 1 of varying exterior diameter for carrying off the fluid forced out of the

page_text: cylinder upon the recoil, the construction and arrangement of a cylindrical tube E
in connection with a rod E' of varying diameter in the interior of the piston rod A
by means of which in the inside of the tube the area of the flow is regulated as set
forth.
Dated this 6th day of May 1890.
ALFRED LONGSDON.
By Brewer & Son,
33, Chancery Lane, London, Patent Agents.