Ordnance and the Running Out after Recoil.
Year: 1885

page_text: Ordnance and the Running Out after Recoil.
I, JOSIAH VAVASSEUR of the London Ordnance Works, Bear Lane Southwark
in the County of Surrey Engineer do hereby declare the nature of this invention
to be as follows:-
..
This invention relates to gun carriages in which the recoil is controlled by two
hydraulic compressors in which the piston rods are in tension during recoil and
travel out of the cylinders.
Instead of making both the pistons with the ports or orifices which give passage
to the liquid alike in the two pistons giving an equal pressure in each cylinder
during recoil I make them sufficiently dissimilar to cause throughout the recoil a
greater pressure in one cylinder than in the other. I make a communicating
passage between the cylinders at the end under pressure during recoil so that the
difference of pressure in the cylinders will cause a flow of liquid from the one with
the greater pressure to the one with the lower pressure; the liquid thus added to
the latter passing through the ports or orifices in the piston and filling up the
space at the rear left by the withdrawal of the piston rod during recoil. I make the
communicating passage as large as convenient so that the required velocity of
liquid therein may be small and also that the difference of pressure in the
cylinders may be slight so as not to cause any injurious twisting action.
In the communicating passage I fit a non return valve opening from the cylinder
at the higher pressure. On the carriage tending to run out, the piston rod entering
the low pressure cylinder causes pressure which (the non-return valve being closed)
stops the carriage. To allow the carriage to run out at any required rate without
its being necessary to disturb the non-return valve, I make a bye pass channel
between the two sides of the valve and provide the same with a plug or valve
which if left closed when firing will keep the gun in at the end of recoil and by
suitably opening it the speed of running out can be regulated as desired.
I also in some cases arrange the non-return valve so that it is automatically
raised when the carriage is very nearly run out thereby opening the passage prior
to firing.

page_text: Ordnance and the Running Out after Recoil.
I JOSIAH VAVASSEUR of the London Ordnance Works, Bear Lane Southwark in
the County of Surrey 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 relates to gun carriages in which the recoil is controlled by two 5
hydraulic compressors in which the piston rods are in tension during recoil and
travel out of the cylinders.
Instead of making both the pistons with the ports or orifices which give passage
to the liquid alike in the two pistons giving an equal pressure in each cylinder
during recoil 1 make them sufficiently dissimilar to cause throughout the recoil a 1
greater pressure in one cylinder than in the other. I make a communicating
passage between the cylinders at the end under pressure during recoil so that the
difference of pressure in the cylinders will cause a flow of liquid from the one with
the greater pressure to the one with the lower pressure, the liquid thus added to
the latter passing through the ports or orifices in the piston and filling up the 1
space at the rear left by the withdrawal of the piston rod during recoil. I make
the communicating passage as large as convenient so that the required velocity of
liquid therein may be small and also that the difference of pressure in the
cylinders may be slight so as not to cause any injurious twisting action.
In the communicating passage I fit a non returu valve opening from the cylinder
at the higher pressure. On the carriage tending to run out, the piston rod,
entering the low pressure cylinder causes pressure which (the non return valve
being closed) stops the carriage. To allow the carriage to run out at any required
rate without its being necessary to disturb the non retura valve, I make a by pass
channel between the two sides of the valve and provide the same with a plug or
valve which if left closed when firing will keep the gun in at the end of recoil and
by suitably opening it the speed of running out can be regulated as desired.
I also in some cases arrange the non-return valve so that it is automatically
raised when the carriage is very nearly run out thereby opening the passage prior
to firing.
In order that my said invention may be fully understood and readily carried into
effect I will proceed to describe the drawings hereunto annexed.

page_text: A A are bearings in which the trunnions of the gun are carried-and A¹ A² are
the cylinders of the hydraulic compressers; they are formed in the two side cheeks
of the gun carriage. B is the slide which the carriage ascends when the gun
recoils. On the front of the slide are projections B¹ B to which are fixed the
rods CC of the pistons D1 D2 which are contained in the compressor cylinders.
There are orifices D* in the pistons, and these orifices are progressively closed as
the gun runs back. For this purpose there is on each piston a moveable disc
which engages with rifle grooves formed in the compressor cylinders; the disc is
thus caused to partially rotate as the gun recoils and shut the orifices. This
method of closing the orifices in the pistons of hydraulic compressors is now well
known and it forms no part of my present invention, but, as will be observed,
I make the orifices in the two pistons of different dimensions so that a higher
pressure is generated during recoil in front of the piston with the smaller orifices
than occurs in the cylinder of the other hydraulic compressor. The two cylinders
are connected by a cross passage E and in consequence of the difference of pressure
in the two cylinders liquid flows during the recoil from the one cylinder to the
other. It lifts in its passage the valve F which immediately closes to prevent
return. Or if desired mechanism may be provided to hold this valve open when
the gun is fully run out ready for firing, so that as little resistance as may be shall
be offered to the passage of liquid from one cylinder to the other.
In consequence of these arrangements it happens that at the end of the recoil
one of the cylinders viz; that containing the piston with the larger apertures, is
full of liquid notwithstanding that the piston rod has passed out from the cylinder
during the rearward motion of the gun. The liquid now cannot flow back from
this cylinder to the other cylinder because the valve F closes against it and the gun
consequently cannot run out down the inclined slide because the piston rod is
unable to enter the cylinder which is full of liquid. Hence the gun consequently
remains at rest until it is desired that it should run out, and then to permit it to
do so the valve G on the bye-pass passage is opened, the excess of liquid in the
cylinder A² then passes back into the cylinder A¹ whilst the gun runs forward to
the firing position.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is:-
1. Apparatus for controlling the recoil and the running out of ordnance and
consisting of two bydraulic compressors in the cylinders of which unequal pressure
is produced during recoil and liquid caused to pass from one cylinder to another;
such liquid then filling the void space left on withdrawal of a piston rod so that
the said rod cannot return or the gun run out until a passage for the liquid is
opened.
2. Apparatus substantially as represented by the annexed drawings for controlling
the recoil and running out of ordnance.