IMPROVEMENTS IN HYDRAULIC FORGING MACHINERY
Year: 1884

page_text: I CHARLES DAVY of 24 Lawson Road Sheffield in the County of York, Engineer
do hereby declare the nature of the said invention for "IMPROVEMENTS IN HYDRAULIC
FORGING MACHINERY" to be as follows:-
This Invention relates to improvements in bydraulic forging machinery specially
applicable to forging large masses of steel or iron.
To carry out my invention I construct a press having two rams hereinafter
called the main rams, acting vertically upon a moving crosshead or tool holder
and forcing it downwards, thus applying the necessary pressure to an ingot or
other piece of steel or iron to be forged.
The rams work in ram cases supported in the usual manner on two or more
columns attached to a foundation plate or bed plate. The rams are hollow
cylinders closed at their upper ends, and are provided with connecting rods having
simple, or preferably universal joints at either end, the lower ends being connected
to the moving crosshead or tool holder.
The moving crosshead is provided in the centre of its length with an arm pro-
jecting upwards into a guide supported midway between the two ram cases, the
upper end of the arm being made to fit the guide loosely. The ends of the moving
crosshead are provided with loosely fitted guide blocks encircling the supporting
columns or otherwise guided.
For the purpose of lifting the moving crosshead, after a downward stroke,
I employ one or more rams, hereinafter called the lifting rams, with their cases and
their appurtenances of smaller size than the main rams, but preferably of the same
length of stroke, and connected to the moving crosshead by simple, or preferably,
universal jointed rods.
It is an essential part of my invention, to relieve the rams and the guides from
undue side strains and consequent friction, arising from the nature of the work or
from the expansion of the moving crosshead by heat, and I accomplish my object
by the system of guides and jointed connecting rods already described.
The apparatus in connection with the press, consists essentially of an air
receiver, which is partially filled with water at a low pressure; a set of high
pressure pumps, capable of being stopped or started quickly; and a system of
valves for the admission and discharge of water to and from the main ram cases
and lifting ram case or cases.

page_text: I connect the main ram cases to the lower part of the air receiver, by a range of
pipes in which I place a valve for opening or closing communication. The suction
valves of the high pressure pumps and the discharge valve or valves of the lifting
ram case or cases, are in communication with the air receiver by pipes. The
delivery pipe or pipes from the high pressure pumps are furnished with two valves,
one of which opens or closes communication between the high pressure pumps and
the main rain cases, and the other fulfils the same purpose in respect to the lifting
ram case or cases.
By opening and closing alternately in proper sequence, the admission and
discharge valves, I place the main ram cases and lifting ram case or cases alternately
in communication with the air receiver and with the high pressure pumps, and
I thereby obtain, at will, either a rapid or slow motion of the rams and parts
connected therewith.
By this arrangement, when the pressure pumps are placed in communication
with the main ram cases, the water in the lifting ram case or cases is forced back
into the air receiver; and vice versa when the high pressure pumps are placed in
communication with the lifting ram case or cases, the water in the main ram cases
is forced back into the receiver, so that it is only necessary to pump sufficient
water into the receiver to compensate for leakage.
Instead of returning the water to the air receiver as above described, the high
pressure pumps may draw their water from an open tank; and the water from the
rain cases may be allowed to run to waste. In this case it will be necessary to
provide separate pumps of sufficient capacity for maintaining the pressure in the
air receiver.
I prefer to drive the high pressure pumps by a pair of steam or other engines
the regulating valve of which may be opened and closed by mechanism so arranged
that the engines will make any desired number of revolutions or parts of a
revolution.
For this purpose I provide two screws carried in journals and placed with their
axes parallel and at a convenient distance apart. One of the screws is provided
with a hand wheel or its equivalent, and may be caused to rotate on its axis by an
attendant, the other screw being rotated in a contrary direction by spur or other
gear taking motion from any revolving part of the engines. A worm wheel whose
teeth gear with the screws, is mounted on an axle, and is placed midway between
the screws in such a way that it is free to reciprocate bodily in a direction parallel
therewith. A rod or rods, connected in a convenient way to the axle of the worm
wheel, conveys motion to the regulating valve of the engines.

page_text: I CHARLES DAVY of 24 Lawson Road Sheffield in the County of York, Engineer
do hereby declare the nature of my invention for IMPROVEMENTS IN HYDRAULIC
FORGING MACHINERY 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 bydraulic forging machinery specially
applicable to forging large masses of steel or iron.
The invention has for its object to avoid undue friction on the working parts
(rams, guides &c) of the press, in consequence of the expansion by heat of the parts
in proximity to the ingot, or in consequence of the nature or position of the work;
and also to more effectually guide the moving crosshead of the press; and to
provide an improved method of working the main and lifting rams of the press by
high and low pressure water in such manner as to economize the high pressure
water, and obtain a quick motion of the moving crosshend towards and away from
its work.
•
In order that the invention may be more readily understood I have illustrated it
in the accompanying drawings forming part of this specification wherein
Figure 1 is a front elevation partly in section, of the press. Figure 2 is a corre-
sponding elevation of the engines, valve gear, and air vessel, showing the pipe
connections to the various rams of the press. Figure 3 is a plan, partly in section,
of the press head and rams. Figure 4 is a vertical section (partly through the
central guide of the moving crosshead). Figures 5 and 6 are respectively an end
elevation and plan of the guide blocks of the moving crosshead. Figures 7 and 8
show details, on a larger scale, of the connections of the lifting rains and their
crossheads. Figures 9 and 10 are front and side elevations (on a larger scale) of
the valve gear shown in Figure 2. Figure 11 is a central vertical section on a
larger scale of one of the compound automatic valves, shown applied to the pressing
ramis in figure 1. Figure 12 shows a slight modification of figure 11. Figure 13
is a central vertical section (on a larger scale) of one of the hydraulic valves shown
in figures 2, 9 and 10.
The particular construction of the valves shown in figures 11, 12, and 13 forms
the subject of another application for Letters Patent dated February 25th 1885.
To carry out my invention I construct a press having a pair of inverted rams a a
(hereinafter called the pressing rams) which act upon a movable crosshead or tool
holder b, and force it in the direction of the work, for applying the necessary
pressure to an ingot or other piece of steel or iron to be forged.
The pressing rams a work in ram cases c fixed in the press-head and supported
in the usual manner on four columns attached to a foundation or bed plate. The
rams a are bollow cylinders or trunks closed at their upper ends, and they transmit
the pressure to the crosshead b, through thrust rods d having simple (or preferably,
universal ie ball and socket) joints at their upper and lower ends in order to

page_text: permit of any horizontal deviation, or rocking motion, of the crosshead (due to the
above mentioned causes) without throwing undue lateral strains on the rams a, or
their cases c. The movable crosshead b is provided in the centre of its length with
a rigid arm or tail piece e, projecting upwards and terminating in a head or block
that works loosely in a cylindrical guide frigidly supported on the press head
midway between the two ram cases c. The rigid arm or tail piece e may be cast
upon, or forged solid with, the crosshead, or secured thereto by bolts or by hoops
shrunk on projecting half bosses on the tail-piece and crosshead. The ends of the
moving crosshead b, terminate in gudgeons b₁ and fit (with sufficient clearance to
allow of the expansion of the crosshead by heat) in the manner of a ball and sockot,
in guide blocks g, which guide blocks g encircle and work upon the supporting
columns or are otherwise guided, the gudgeons being midway between a pair of
columns (when four are used) as shown in figure 7.
For the purpose of lifting the moving crosshead b after a downward stroke,
I employ one or more rams h (preferably two) hereinafter called the lifting rams.
These rams are contained in cases i and they are of considerably smaller area
than the pressing rams, but preferably of the same length of stroke; and they are
connected to the end gudgeons b' of the moving crosshead b, by pairs of rods
and small crossheads which are connected to the rains h, and gudgeons b' of
crosshead b, in such way as to form simple (or preferably universal) joints as
shown.
To facilitate the changing of the packing, the lifting rams h have flanges forged
or cast upon their upper ends for the purpose of securing them to the crossheads h¹
and at the same time to permit of their easy removal; and the crossheads h¹ have
holes in them sufficiently large to allow of the lifting rams passing through, and
are also provided with bolt holes corresponding with holes in the flanges of the
rams, so that when the bolts are removed the rams may be withdrawn from their
cases through the crossheads.
If only one lifting ram is used it may be fixed centrally over the tail piece e
and be connected thereto or to the crosshead b by suitable rods and joints.
It is an essential object of my invention to relieve the rams, particularly the
pressing rams, and the columns (or other guides of the moving crosshead) from
undue side strains and consequent friction arising from the nature of the work
or from the expansion of the moving crosshead by heat; and I accomplish my
object by the system of guides and ball and socket thrust rod bearings already
described.
The press may be arranged to work horizontally instead of vertically as will be
readily understood.
The apparatus in connection with the press consists of an air vessel (or an
accumulator) which is partially filled with water at a pressure sufficient to cause
the pressing ram cases to be filled with water when the rams and crosshead
descend with the rapidity desired; a set of high pressure pumps m capable of
being stopped or started quickly; and a system of valves Nos 1, and 1 and
Numbers 2. 3. 4 for the admission and discharge of water to and from the pressing
ram cases and lifting ram case or cases.
The upper ends of the pressing ram cases c are connected to the lower part of
the air vessel 1, by the low pressure main n, on which (as near as possible to the
rams) are placed the compound automatic valves 1 and 1 (or a single valve) for
automatically opening and closing communication of the pressing rain cases c with
the air vessel. The chambers of valves Numbers 1 and 1 are also connected (above
the valves) by a pipe q with the delivery pipe p of the high pressure pumps the
communication being controlled by valve N° 3.
The lower ends of the lifting ram cases i are connected by a pipe o, with the low
pressure main n, and with the other delivery pipe p' of the high pressure pumps m,
the communication of said pipe o, with the main n or with the delivery pipe pl
being controlled by the valves Numbers 2 and 4 respectively.

page_text: The suction valves of the high pressure pumps m are in communication with
the low pressure main n and air vessel Z.
I will here describe the construction and operation of the compound automatic
valves Nos 1, 1.
Referring to figures 11 and 12 this valve consists of a tubular plug w contained
in a suitable casing w said plug closing against a seat at the lower part of the
casing and controlling the communication between the pressing ram case c and the
low pressure main n. This plug w is of two diameters and is fitted to slide in a
corresponding bushing w provided with suitable cup leather or other packings w³.
Between the plug and bushing an annular chamber w* is formed which is in free
communication by a pipe w with the lifting.ram cases or the pipe o so that on
admitting high pressure water to the lifting ram cases it is at same time admitted
to the annular chamber w whereby the plug w is lifted from its seat to allow the
water in the pressing ram cases to return through the low pressure main n to the
air vessel.
This annular chamber is of such area that the pressure exerted therein is
sufficient to keep the valve w open to the low pressure main n in order to allow
the pressing ram cases c to be refilled with water on the descent of the pressing
rains a. Within the tubular plug wis seated an inner valve w opening in the
opposite direction to the plug or valve w and controlling the communication
through the tubular valve w of the high pressure main g with the pressing ram
cases c. This inner valve w opens with the pressure and is loaded by a spring w
sufficiently to cause the plug w to be closed (by the high pressure water from
main q acting on the back or upper end of plug w) before the inner valve we will
open to allow the high pressure water to enter the pressing ram cases c. The
pressure which tends to close the plug w suffices to keep it closed and prevent high
pressure water leaking past it into the low pressure main n.
The spring wis contained in a chamber within plug w and is compressed
between the end of said chamber and a flanged head w attached to the rod wº of
valve the spring being confined in the chamber by a lining w⁰ to which the
head w is attached.
The area of the upper or rear side of the plug w although always greater than
the orifice of its seat inay be less than that shown in figure 11 by surrounding the
plug with a second annular chamber (as shown in figure 12) which is in free com-
munication by a hole wl with the atmosphere so as to minimise the pressure
tending to close the plug wou to its seat and allow the pressure exerted in the
first mentioned annular chamber w to act with greater effect when it contains
only low pressure water (as for instance whilst the press is at rest) whereby tho
plug w will under ordinary circumstances be maintained in its open position.
I will now describe the construction and operation of the valves No. 2, 3, and 4
for controlling the admission and exhaust of water to and from the pressing and
lifting ram cases. These valves are alike and one of them is represented in
figure 13. This valve is of the "floating" or "pilot" type that is to say it is com-
posed of an outer tubular valve or plug z and an inner or "pilot" valve y seated
within the outer valve and opening in the same. direction. The valve or plug
slides within a suitably packed guide cylinder or bushing closed at the upper
part in which the plug works as a piston in a cylinder the plug x being so fitted
therein as to allow a slight leakage of water to pass to the top side of the plug (or
a bye pass being provided for the same purpose) in order to admit sufficient
pressure to the upper side of the plug x to keep it closed down on its seat this
pressure being released when the pilot valve is opened, the plug x being then in
equilibrium and therefore easily lifted.
The pilot valve y is attached to or formed on the end of the spindle y' which is
provided with wings y having a limited play in the plug in order to cause the
latter to be raised from its seat after the pilot valve y has been opened by the
motion of said spindle y'. The special feature of improvement in the construction

page_text: of these valves consists in providing a balancing ram y³ working in a cylinder y
at the opposite end of the spindle to that at which the pilot valve y is situated the
said balancing ram being of about the same area as the pilot valve y and its
cylinder being in communication by a pipe with the space at the underside of
the valve; the plug x and valve y being thus both in a condition of equilibrium.
The motion is imparted to the spindle y¹ for opening valves y in the order above
mentioned and for closing them in the opposite order by an auxiliary piston z
acting on a lever 2³ connected to spindle y' the said piston working in a cylinder
and being acted on by fluid pressure derived from the air vessel (or it may be
from an independent source or by steam power).
The supply and exhaust pipes to and from the various cylinders of the valves
No 2, 3 and 4 in figures 29 and 10 are controlled by three small slide valves
working in a common chamber v (or it may be separate chambers) and respectively
actuated by three hand levers 2 3 4 corresponding respectively to the valves
N° 2, 3, 4.
I will now describe the method of working the press and the proper sequence
for opening and closing the valves. Assuming the air vessel to be charged, the
crosshead b to be at the bottom of its stroke, and the valves N° 23 and 4 closed,
the valve N° 4 is first opened. The pumps being then started high pressure water
is forced through pipe o into the lifting ram cases i and into the annular chamber
of each valve N° 1 whereby the valves N° 1, 1 are opened. The superior pressure
exerted on the lifting rams raises the crosshead b, and forces the water from the
pressing ram cases through the low pressure main n into the air vessel, where the
power expended in overcoming the action of the low pressure water on the pressing
rams, is stored up. As the delivery of the pumps is large relatively to the capacity
of the lifting ram cases the ascent of the crosshend is very rapid. When the
crosshead is raised to the desired height the pumps are stopped and the valve
N° 4 is closed. The crosshead is lowered when required by opening the valve N° 2
the valves N° 1, 1, being held open by the pressure in pipe o acting in their
annular chambers whereupon the crosshead and pressing rams descend to the
required point by their own gravity (in the case of a vertical press such as that
illustrated) aided by the differential pressure due to the difference of area of the
pressing and lifting rams, (or wholly by such differential pressure in the case of
a horizontal press) the water in the lifting ram cases i being returned to the air
vessel through the low pressure main n whilst the pressing ram cases are filled
with low pressure water. The valves 1, 1, and pipe being of large diameter the
descent of the crosshead may be very rapid. Valve No 2 being left open the
working pressure is applied at the required moment by opening valve N° 3 and
starting the pumps whereupon the valves N° 1, 1 automatically close the com-
munication between the air vessel and the pressing ram cases c and open the
communication with the pipe q whereby high pressure is applied in the pressing
ram cases c and the forging is subjected to the necessary pressure. The pumps
being stopped, the valves 2 and 3 are closed and the cycle of operations repeated.
By this arrangement it is only necessary to pump sufficient water into the air
vessel to compensate for leakage.
Instead of returning the water to the air vessel as above described, the high
pressure pumps may draw their water from an open tank; and the water from the
ram cases may be allowed to run to waste. In this case it will be necessary to
provide separate pumps of sufficient capacity for maintaining the pressure in the
air vessel.
I prefer to drive the high pressure pumps m by a pair of steam or other engines
the regulating valve of which may be opened and closed by mechanism so arranged
that the engines will make any desired number of revolutions or parts of a
revolution and then stop automatically. For this purpose I control the regulating
valve by means of what is designated a "hunting gear" the preferred arrangement
consisting of two similar screws 7. 8 figures 9 and 10 placed with their axes

page_text: parallel and journaled in bearings at a convenient distance apart. One of the
screws is provided with a hand wheel, or its equivalent, and may be caused to
rotate on its axis by an attendant, the other screw being rotated in a contrary
direction by spur or other gear taking motion from any revolving part of the
engines. A worm wheel t mounted between the screws, gears with both of them
at once, and its axle is carried by slide blocks fitted in guides. When one of the
screws is rotated the wheel is caused to turn, the other screw acting for the time
being as a rack, a reciprocating motion being thereby imparted to the wheel axle
for the purpose of operating the regulating valve of the engine, with which the
said axle is connected by any suitable means. The one screw is turned by land
when it is desired to start the engines, the other screws being driven in the
opposite direction by spur or other gear u receiving motion from the engine shaft,
and thus counteracting the effect of turning the hand screw, and tending to return
the wheel to its normal position which corresponds to the closed position of the
valve. By this means the valve is eventually closed in a longer or shorter time
after the hand screw is stopped according to the distance the wheel was displaced
from its normal position.
The screw 8 is driven through the medium of a friction clutch 81 in order to
guard against the possibility of the pumping engines continuing in motion after
the steain is shut off, owing to the presence of steam in the steam chests. Should
"the hand wheel the friction clutch will be lifted
the pumping engines "overrun
out of gear by the T shaped lever connected with the worm wheel axle thus
avoiding breakage.
The method of working above described is not limited to the particular press
herein before described but is applicable to other hydraulic forging presses in which
one or more pressing rams and one or more return or lifting rams acting in the
opposite direction to the pressing rams are used.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is
1st In a hydraulic forging press the combination with the moving crosshead or
tool holder, of a rigid arm or tailpiece extending through the presshead and working
in a vertical guide above or beyond the presshead, substantially as shown and
described for the purpose specified.
2nd In a hydraulic forging press the construction of each pressing ram in the
form of a hollow trunk or cylinder, closed at the inner end, and the combination
therewith and with the moving crosshead, of a thrust rod working on a joint at
each end substantially in the manner and for the purpose specified.
3rd The combination and arrangement substantially as shown and described of
the moving crosshead or toolholder, its central rigid arm or tailpiece and guide-
cylinder therefor, the pair of pressing ram cases and rams constructed in the form
of hollow trunks, thrust rods working on universal joints between the rams and
crosshead, and the universal joints between the ends of the crosshead and their
guide blocks, all for the purpose of permitting a slight horizontal deviation or
rocking motion of the crosshead without throwing undue side strains on the rams
and guides of the press.
4th The combination with the subject of the last preceding claim, of the system
of jointed connections coupling the lifting rams and crosshead, substantially as
described.
5th The combination with a hydraulic forging press having pressing and lifting
or return rams (one or more of each) acting in opposite directions and of different
areas, of an air vessel (or an accumulator) a set of high pressure pumps, pipe
connections, and valves, so arranged and operated that the crosshead will be
brought into working position in the manner described; the working pressure
applied by the differential power of high pressure water acting on the pressing

page_text: ram or rams opposed by low pressure water on the lifting ram or rams; and the
crosshead raised out of work by the differential power of high pressure water
acting on the lifting ram or rams, and opposed by low pressure water acting on the
pressing ram or rams; whereby power is economized, a quick motion of the cross-
head towards and away from its work is obtained, and the same water used over
and over again substantially as specified.