IMPROVEMENTS IN
Year: 1873

page_text: LETTERS PATENT to George Wightwick Rendel, of Elswick. Works,
Newcastle-upon-Tyne, for the Invention of . IMPROVEMENTS IN
' "
66
Sealed the 20th June 1873, and dated the 27th March 1873.
.
PROVISIONAL SPECIFICATION left by the said George Wightwick
Rendel at the Office of the Commissioners of Patents, with his
Petition, on the 27th March 1873..
I, GEORGE WIGHTWICK RENDEL, of Elswich Works, Newcastle-upon-
Tyne, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN HYDRAULIC MACHINERY FOR WORKING ORDNANCE," to be as follows:-
The improvements are chiefly applicable to cases where the hydraulic
power is obtained by pumps forcing water or other liquid into an
accumulator consisting of a loaded cylinder or. of an air vessel.
I apply the hydraulic power for the purpose of training guns by the
action of hydraulic cylinders or presses. I use these cylinders in a
manner similar to that in which they are employed for turning hydraulic

page_text: cranes, the chain through which the hydraulic power is transmitted to
the gun carriage or platform being passed round and attached to an are
or drum fixed on the gun slide or platforni; and so arranged that when
the water is admitted to one cylinder under pressure, and allowed to
escape from the other, the chain is pulled in one direction and draws
with it the gun, and similarly when the pressure is thrown on the other
cylinder, motion is given to the gun in the opposite direction. Or, the
arc may be dispensed with and the cylinders placed in any convenient
position in the battery, and chains led from them over conveyance
sheaves and attached at will to any desired point in the gun slide or
platform. Or, I employ one or more cylinders acting direct upon the
slide or platform through a connecting rod attached on a pivot to the
platform: Or, the arrangement may be varied by placing the cylinders
or cylinder on the platform or slide, and making the attachments to fixed
points off the slide; or, the cylinders or presses may be applied on any
of the known methods for producing a similar traversing or rotating
motion.
I further apply the hydraulic power in one or more cylinders, each
fitted with a piston and piston rod for the purpose of running the gun in
and out along the slide, the water being admitted to and allowed to
escape from each end of the cylinder by working valves placed in
convenient positions, and I place on the back end of the cylinder a
self-acting valve of the nature of a safety valve, loaded to any required
pressure for the purpose of checking the recoil of the gun when fired.
The cylinder is fixed on the platform or slide in a line parallel to the
direction of recoil, and the end of the piston rod is attached to the
carriage so as to travel with it. Thus, when the hydraulic pressure is
admitted to either side of the piston, it forces the piston along and moves
the carriage with the piston; but, when the gun is fired, the working
valves remaining closed, the water can only escape from the back side
of the piston through the loaded valve, and the obstruction this offers to
its progress arrests the recoil. I apply to the loaded valve a simple
means of adjusting the weight upon it to meet variations of recoil due
to varying charges and conditions of friction, &c.; but, the pressure
required to run the gun in and out being less than that attained in
arresting recoil, the loaded valve is weighted sufficiently to prevent the
escape of the water during the ordinary working of the cylinder. I
supply the cylinder with water to keep it full on the opposite side of the

page_text: piston to that from which the water is expelled by the recoil, by means
of a clack and suction valve communicating with a tank.
I may of course substitute for cach cylinder with piston and piston
rod, a pair of cylinders working in opposite directions with a simple
plunger in each, and I may also obviously use an independent cylinder
or cylinders and valve for arresting recoil, but the arrangement I prefer
is that in which one cylinder accomplishes both the running in and out
and the arresting of recoil in the manner described.
I also use the cylinder as above described in cases where no hydraulic
power is used for the purpose of checking recoil and controlling the
movement of the gun when run in and out by chain gear or other
appliances; and in this case I connect one side of the piston with the
other by means of a small pipe, or otherwise interrupted by a stop valve
which serves to give control over the motion of the gun by governing
the passage of the water from one side of the piston to the other; and
because the volume of water to be displaced from one side of the piston
is greater than can be received on the other by the amount of displace-
ment of the piston rod, I provide an outlet for the superfluous quantity
by a special passage in the stop valve. The deficiency of water which
results from the opposite movement is supplied by the clack or suction
valve already described. Thus the cylinder remains always full and
ready for immediate action. I retain the loaded valve, as described, for
the purpose of checking recoil.
I further apply the hydraulic power for the purpose of depressing and
elevating the gun for loading, or for giving the required elevation when
firing, and for this purpose I use a cylinder and plunger fixed on the
carriage or on the platform in a suitable position near the breech of the
gun.
When the cylinder is fixed on the carriage the water may be admitted
by a passage through the piston rod of the running in and out or recoil
cylinder, with a valve or valves to control the admission and escape of
the water, or the water may be admitted by jointed or flexible pipes, or
by other means. The gun may have preponderance at the breech, so
that when the water is allowed to escape from the cylinder the pre-
ponderance of the gun brings the breech down, and when the plunger is
forced out by the admission of water the gun is depressed at the muzzle.
Or, the cylinder may be made double acting by the use of a piston and

page_text: piston rod instead of a plunger, in which case the gun may be depressed
and elevated by the cylinder independently of preponderance.
If the cylinder instead of travelling with the carriage is made a
fixture beneath the gun I apply it at the points at which the elevation
and depression is to be performed, and if there be more than one such
point I apply more than one cylinder.
"
"
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said George Wightwick Rendel in the Great Seal
Patent Office on the 27th September 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
WIGHTWICK RENDEL, of Elswick Works, Newcastle-upon-Tyne, send.
greeting.
.
WHEREAS Her most Excellent Majesty Queen Victoria, by. Her
Letters Patent, bearing date the Twenty-seventh day of March, in the
year of our Lord One thousand eight hundred and seventy-three, in the
thirty-sixth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said George Wightwick Rendel, Her
special license that I, the said George Wightwick Rendel, my executors,
administrators, and assigns, or such others as I, the said George
Wightwick Rendel, my executors, administrators, and assigns, should
at any time agree with, and no others, from time to time and at
all times thereafter during the term therein expressed, should and
lawfully might make, use, exercise, and vend, within the United
Kingdom of Great Britain and Ireland, the Channel Islands, and
Isle of Man, an Invention for "IMPROVEMENTS IN HYDRAULIC MACHINERY
FOR WORKING ORDNANCE," upon the condition (amongst others) that I,
the said George Wightwick Rendel, my executors or administrators,
by an instrument in writing under my, or their, or one of their hands
and seals, should particularly describe and ascertain the nature of the
said Invention, and in what manner the same was to be performed,
and cause the same to be filed in the Great Seal Patent Office within
six calendar months next and immediately after the date of the said
Letters Patent...

page_text: NOW KNOW YE, that I, the said George Wightwick Rendel, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement thereof, that is to say :-
The improvements are chiefly applicable to cases where the hydraulic
power is obtained by pumps forcing water or other liquid into an
accumulator consisting of a loaded cylinder or of an air vessel. I may
derive the hydraulic power however from the natural head of water
stored at a sufficient elevation or from the direct action of pumps'
without the intervention of accumulators. I may also obviously employ
in certain cases any other liquid such as oil or glycerine in place of
water.
I apply the hydraulic power for the purpose of training guns by the
action of hydraulic cylinders or presses. I use these cylinders in a
manner similar to that in which they are employed for turning hydraulic
cranes, the chain through which the hydraulic power is transmitted to
the gun carriage or platform being passed round and attached to an arc
or drum fixed on the gun slide or platform, and so arranged that when
the water is admitted to one cylinder under pressure and allowed to
escape from the other the chain is pulled in one direction and draws
with it the gun, and similarly when the pressure is thrown on the other
cylinder motion is given to the gun in the opposite direction. Sheet 1
shows an arrangement of this description.
Figure 1 is a side elevation, and Figure 2 is a plan; a is the gun with
its carriage a¹; b is the gun slide or platform mounted on rollers
running on the circular rail c, and also on a centre pivot. 6¹ is an arc
or drum on the slide or platform surrounding the pivot; d, d, are chains
passing. around the arc in opposite directions and over guide pulleys and
pulleys on the heads of the rams e, e, to attachments on the cylinders e¹, e¹,
of the rams by a slide valve; the water under pressure is admitted to
either cylinder, whilst the contents of the other is allowed to escape and
so the gun is trained to one side or the other. Or the arc may be
dispensed with and the cylinders placed in any convenient position in
the battery and chains led from them over conveyance sheaves and.
attached at will to any desired point in the gun slide or platform.
Figure 2, Sheet II., shews in plan an arrangement of this description.
The gun slide or platform is pivotted at 6', and is supported by rollers

page_text: slide and pass
Water under
running on the rail c. The chains d are attached to the
over guide pulleys to the rams and fixed cylinders e, e¹.
pressure is supplied to the cylinders as already described, and to multiply
the length of the stroke the chains are passed over pulleys around the
cylinders and rams as the Drawing indicates; or I employ one or more
cylinders acting direct upon the slide or platform through a connecting
rod attached on a pivot to the platform.
Figure 3, Sheet II., shews in plan an arrangement of this description;
bis the gun slide or platform with its pivot b¹; c, the supporting rail as
before; e is a fixed hydraulic cylinder containing a piston, on either side-
of which the water can be admitted by a slide valve; e² is a connecting
rod coupling the piston rod with the slide or platform; or I may employ
a hydraulic engine to turn toothed wheels gearing into a circular arc or
rack on the gun carriage platform.
Sheet III., shews an arrangement of this nature. Figure 1 is a side
clevation; Figure 2, a plan; and Figure 3 a back view; the parts a, a¹,
b, c, correspond to those similarly marked on Figure.1; d is a hydraulic
engine fixed beneath the slide or platform, and driving the pinion d
gearing with a rack b² on the under side of the slide or platform; or the
arrangements may be varied by placing the cylinders, or cylinder, or
engine on the platform or slide, and making the attachments to fixed
points off the slide, the water being introduced through a pipe at the
centre of motion of the slide in a similar manner to that indicated at Z
on Sheet IV., or it may be through a jointed pipe. Figure 1, Sheet II.,
shews in plan an arrangement of this nature. The cylinders c¹, c¹, in
place of being fixed as in Figure 1 are here mounted upon the gun slide
or platform, and the chain d is attached round a drum fixed on the pivot
block or ground. I further apply the hydraulic power in one or more
cylinders, each fitted with a piston and piston rod for the purpose of
running the gun in and out along the slide, the water being admitted to
and allowed to escape from cach end of the cylinder by working valves
placed in convenient. positions, and I provide an outlet for the water
which is displaced from one side of the piston on recoil past a self-acting
. valve of the nature of a safety valve loaded to any required pressure for
the purpose of checking and arresting the force of recoil of the gun
when fired.
T
aunted to aun haakwouds and forwards

page_text: on a slide or platform, the recoil cylinder may be fixed on the platform
or slide and the piston rod attached to the carriage direct or through a
connecting rod or chain or otherwise, so as to move with the carriage.
Thus when the hydraulic pressure is admitted to either side of the piston
it forces the piston along and moves the gun with the piston, but when
the gun is fired the working valve remaining closed the water can only
escape from the back side of the piston through the loaded valve, and the
obstruction this offers to its passage arrests the recoil. I apply to the loaded
valve a simple means of adjusting the weight upon it to meet variations
of recoil (such as a lever and adjustable spring as in a locomotive steam
safety valve, or a lever and sliding weight), due to varying charges and
conditions of friction, &c., but the pressure required to run the gun out
on a slide being usually less than that attained in arresting recoil, the
loaded or recoil vale when weighted sufficiently to check recoil along a
slide will not rise and allow the water to escape on its being admitted by
the ordinary working valves for the purpose of running the carriage out.
To provide however for cases in which the working pressure in the
cylinder exceeds that due to recoil I arrange the apparatus by which the
working valves are moved, so that its first action is to increase the load
upon the recoil valve either by laying an additional weight upon it or by
admitting the water supplied under pressure from the pumps to a small
press acting on the recoil valve lever. Thus the very act of setting in
motion the working valves for the purpose of admitting water under
pressure from the water supply pipe to the cylinder under the recoil
valve, increases the load on the recoil valve to any exent required to
prevent the escape of the water through that valve, and the stopping of
the action again removes the weight leaving the recoil valve loaded only
to the extent required to check recoil.
Sheet V. shews an arrangement of this nature adapted to a carriage
running on a slide or platform. (A) is the press, it is attached to the
slide or platform, and its piston rod (B) is attached to the gun carriage; .
(C) is a slide valve for admitting the water under pressure from the
pumps or accumulator to the press (A) to set the piston in motion;
(D) is the recoil valve, weighted by a lever (E) and box spring (F);
(G) is the small press for throwing extra load on the recoil valve lever,
(H) are the valves admitting the water to and allowing it to escape
from this small press (G); (I) is the lever for setting in motion the
working valve (C). It will be seen that the first effect of moving the
lever (I) in a direction to admit the water to the side of the press under

page_text: .
the recoil valve is to open the valve admitting water to the press (G),
and so to increase the load on the recoil valve. The lever (I) is so
arranged that when released it always stands in a position to keep
open the exhaust valve, in the valve case (H) in connection with the
small press (G).
On Sheet IV. is shewn a similar arrangement for loading the recoil
valve prior to admitting the water under it, but in this arrangement the
extra load is given by adding a weight (G) instead of by water pressure
acting in a small press as above described. This Figure is lettered to
correspond with the description of Sheet V., a ram B is however here
shewn in place of a piston; this would be employed when the apparatus
is not required to run the gun in. At Z is shewn the arrangement
for bringing up the pressure and exhaust pipes at the centre of the pivot
on to the slide or platform.
:
The arrangements above described for regulating recoil and for
combining the means of doing so with the working of hydraulic presses
for moving the gun are also especially applicable to the case of a gun
mounted so that it may be raised by the action of an hydraulic press or
presses to deliver its fire over a parapet or other protecting cover, the
same press or presses serving to arrest recoil and regulate the fall of
the
gun.
When I use a piston, as shewn on Sheet V., I supply water from a
tank through a clack valve to keep the cylinder full on the opposite side
to that from which the water is expelled by the recoil, or I lead the
water by a direct passage to the opposite side of the piston after it has
passed the recoil valve. I may of course substitute for each cylinder
with piston and piston rod a pair of cylinders working in opposite direc-
tions with a simple plunger in each, and I may also obviously use a
separate cylinder or cylinders for arresting recoil and for moving the
gun. I prefer however in any case an arrangement in which the same
cylinder accomplishes both the movement of the gun and the arresting
of recoil.
I do not always employ a cylinder or cylinders and recoil valve as
above described in combination with hydraulic power for moving the
gun, but I employ it also alone for the purpose of checking and regu-
lating recoil and of giving control over the movement of a gun carriage
on its slide either at sea or on land.

page_text: Sheet VI., Figures 1 and 2, shew an arrangement I prefer to employ.
In this arrangement an outer cylinder K surrounds the recoil press A,
and serves both as a tank and to maintain a connection between the two
ends of the recoil press. D is the recoil valve, L, L, clack valves sup-
plying water from the outer cylinder as from a tank to keep the recoil
cylinder always full. A small rod and lever enables either of these
valves to be lifted by hand at will, and gives control over the motion of
the gun on the slide by governing the passage of the water out of the
inner press on either side of the piston. This design is applicable for
the conversion of the hydraulic buffer now in use in the Government
service.
Sheet VII. shews another arrangement. Figure 1 is a plan, Figure 2
an elevation, and Figure 3 a transverse section. Figures 4 and 5 are
local sections to a larger scale. So far as the parts are similar they are
lettered to correspond with the description of Figure VI. In the present
arrangement a pipe connection between the two ends of the recoil
cylinder is employed, and a small tank M instead of the combined tank
and pipe shewn as in Sheet VI. A loaded valve N may be introduced
as shewn between the tank and the press to maintain during recoil a
sufficient pressure on the piston rod side of the piston to ensure its being
full, and in the case of a gun slide or platform inclined so that the gun
will run out by its own gravity. The pressure on this valve may be so
adjusted as to give sufficient control over the forward motion of the gun.
By means of the lever O it may then be used to regulate and control the
running out after the gun is loaded, or the recoil valve may be lifted to
allow the water to pass and permit the motion of the gun.
In both the arrangements shewn the displacement on each side of the
piston differs by the amount of displacement of the piston rod, and a
small tank or space in the connecting pipe is required to give and take
the varying volume of water; but this may be avoided, where space
admits, by carrying the piston rod through both ends of the cylinder,
when the volume of water in the cylinder will be the same. In all
positions no tank or outlet will be required, and there may be a close
connection between the two ends of the cylinder, interrupted only by
the recoil valve, which may in that case conveniently be made available
for controlling the motion of the gun in running in or out as well as on
recoil by means of a lever or other appliance to raise it at will. Simi-
larly if I replace the cylinder and piston with a pair of cylinders, cach

page_text: A
provided with a plunger and working in opposite directions, a direct and
close communication may be made between them without any tank or
outlet.
T
frame
I may also obviously attach the presses on the carriage or gun
and make the fixed attachment off the carriage or frame instead of the
converse. In cases where I may find it preferable I further apply the
hydraulic power for the purpose of depressing and elevating the gun.in
loading or laying it. I use a double acting press with a piston and
piston rod, coupled. by a link with the gun. Sheet I. illustrates, this
arrangement. fis the cylinder of the press, and g is a piston rod. It'
has a cross head, from which side rods descend to the ring g', which is
able to slide on the outside of the cylinder f; and h is a link jointed to
the ring and to a projection on the breech of the gun. I may make
the press act upon the gun in front of the trunnions if more con-
venient.
.
I may also, instead of applying the press vertically, place it horizon-
tally on the cheeks of the carriage inside or out, as illustrated in
Sheet III., to keep it under cover from gun fire. In this case, as will
be seen, levers E are fixed on the trunnions of the gun, and links F
connect these levers with the rods F¹ of pistons working in the
cylinders D; or if the gun has a preponderance rams may be substi
tuted for pistons, or I may make the press act through a rack and
pinion upon a toothed arc fixed on the gun, in which case I may com-
bine the working of the hydraulic mechanism for elevating with that of
mechanism to be worked by hand, as illustrated by Sheet VIII.
Figure 1 is an elevation partly in section; Figure 2, a transverse
.section on the line S, S, in Figure 1'; and Figure 3 is a section taken on
the line Y, Y, in Figure 2..
A is an hydraulic cylinder mounted on the gun carriage; B, B, racks
driven by the piston rod C; D, a shaft driven either by the racks B,
engaging with pinions upon it or by the hand elevating gear G; E, cog
wheel on the shaft D; gearing with the tooth arc F bolted to the
cascable of the gun; G is the hand gear, consisting of a spur wheel on.
the shaft D driven by a pinion upon the axis of a hand crank.
- (
The gun may at pleasure be worked either by the hydraulic or the
· hand gear. .

page_text: I introduce the water to the carriage by means of a telescopic pipe
from the slide, the water displaced when the pipe closes escaping into
the pressure pipes through relief valves (valves opening to the pressure),
and being supplied when the telescopic pipe draws out through a clack
valve from a tank.
Having thus described the nature of my said Invention, and the
manner of performing the same, I would have it understood that I claim
as my improvements in hydraulic machinery for working ordnance, -
1. The hydraulic mechanisms for training guns, substantially as
described.
2. The method of checking recoil by means of a piston or ram, forcing
water or liquid past a loaded valve.
3. The arrangement of the said loaded valve, so that it is held upon
its seat whilst the gun is run out.
4. The hydraulic mechanisms for controlling the recoil of guns, sub-
stantially as described.
5. The hydraulic mechanisms for elevating and depressing guns, sub-
stantially as described.
In witness whereof, I, the said George Wightwick Rendel, have
hereunto set my hand and seal, this Twenty-fourth day of Sep-
tember, in the year of our Lord One thousand eight hundred and
seventy-three.