IMPROVEMEnts in HydraULIC MACHINERY
Year: 1875

page_text: LETTERS PATENT to Benjamin Walker and John Frederick Augustus
Pflaum, Engineers, both of Leeds, in the County of York, for the
Invention of "IMPROVEMEnts in HydraULIC MACHINERY.”
Sealed the 10th August 1875, and dated the 26th February 1875.
PROVISIONAL SPECIFICATION left by the said Benjamin Walker and
John Frederick Augustus Pflaum at the Office of the Commis-
sioners of Patents, with their Petition, on the 26th February
1875.
We, BENJAMIN WALKER and JOHN FREDERICK AUGUSTUS Pflaum,
Engineers, both of Leeds, in the County of York, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN HYDRAULIC
MACHINERY," to be as follows:—

page_text: quantity of water drawn from the accumulator is the same whether the
load be light or heavy. To remove this defect we employ the following
arrangement: We pass the chain which is attached to the hydraulic
ram over a guide pulley, and so to a skeleton pulley or drum, which is
so constructed that its effective diameter or its diameter where the chain
takes its bearing can be increased or diminished at pleasure. The pulley
or drum is constructed with two sets of bars inclined in opposite
directions and crossing each other, and the chain lies in the V form
channel between them, and by sliding the bars of the two sets past each
other the distance of their crossing points from the centre of the shaft
which carries the skeleton drum or pulley can be adjusted at pleasure.
There is another drum on the same shaft on which another chain is
wound, and it passes over a guide pulley on the jib to the load.
The action is as follows:-When water is admitted to the hydraulic
cylinder, and so motion is given to the ram, it unwinds the chain from
off the skeleton drum, causing it to rotate, and the drum on the same
shaft is thereby rotated and caused to wind its chain upon it, thereby
lifting the load. If the loads with which the crane is working be light
the skeleton drum is so adjusted as to have a large effective diameter,
and the traverse of the ram will then be short by comparison with the
lift of the load. On the other hand, if the loads be heavy the skeleton
drum is adjusted to a small effective diameter, and then the ram will
traverse over a longer distance.
When applied to hydraulic capstan engines we either place the
skeleton drum on the crank shaft, or use it through the intervention of
belts and wheels, and we sometimes make the pull of the rope bring the
skeleton drum into a line with the pull.
In some cases we attain the same economy without the use of a
skeleton drum by the use of two cylinders and rams. The two rams are
arranged end to end and the hydraulic cylinders are mounted one over
the other; the smaller ram works through a stuffing box at the top of
the lower cylinder. No cup leathers are required; the water does not
go in and out of the cylinders without doing work, and only two glands
are necessary. The valves are so connected with a hand lever that the
first motion of the lever, for the purpose of lifting the load, admits
water from the accumulator to the upper cylinder, where it exerts an
effective pressure on the annulus, corresponding with the difference in

page_text: areas of the two rams.
Should this pressure be insufficient to start the
load the lever hand is moved further, and it then shuts off the upper
cylinder from the accumulator and puts the lower cylinder in com-
munication with it. If in turn this should be found insufficient the
lever is moved a third step, which is the full extent of its motion, and
then both cylinders will be simultaneously in communication with the
accumulator, and the full power of the crane will be exerted.
In the use of ingot cranes as at present constructed a great deal of
power is wasted. In these cranes the jib or arm is mounted on the top
of the ram and is raised at every lift. Now the weight of this jib or
arm and of the ram is very great in comparison with the load of the
crane, and the power expended in lifting them is wasted. To avoid this
we place a second ram and cylinder beneath the main ram and cylinder,
and this auxiliary cylinder is placed in constant communication with the
accumulator. The auxiliary ram aids the main ram in lifting the load,
but when the water is drawn off from beneath the main ram it is
inadequate from its small area to support the weight of the jib and
rams, and these parts descend, forcing back water out of the auxiliary
cylinder into the accumulator.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Benjamin Walker and John Frederick Augustus
Pflaum in the Great Seal Patent Office on the 26th August 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, BENJAMIN
WALKER and JOHN FREDERICK AUGUSTUS PFLAUM, Engineers, both of
Leeds, in the County of York, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-sixth day of February, in the
year of our Lord One thousand eight hundred and seventy-five, in the
thirty-eighth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto us, the said Benjamin Walker and John Frederick
Augustus Pflaum, Her special license that we, the said Benjamin
Walker and John Frederick Augustus Pflaum, our executors, admini-
strators, and assigns, or such others as we, the said Benjamin Walker
and John Frederick Augustus Pflaum, our executors, administrators,

page_text: 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,"
upon the condition (amongst others) that we, the said Benjamin Walker
and John Frederick Augustus Pflaum, our executors or administrators,
by an instrument in writing under our or their hands and seals, or
under the hand and seal of one of us or them, 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.
NOW KNOW YE, that I, the said John Frederick Augustus Pflaum,
on behalf of myself and the said Benjamin Walker, 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:
-
This Invention has for its object improvements in hydraulic
machinery.
When hydraulic cranes or machines of ordinary construction have to
work with varying loads, there is a serious waste of power for the
quantity of water drawn from the accumulator is the same whether the
load be light or heavy. To remove this defect we employ the following
arrangement: We pass the chain which is attached to the hydraulic
ram over a guide pulley, and so to a skeleton pulley or drum which is so
constructed that its effective diameter or its diameter where the chain
takes its bearing can be increased or diminished at pleasure. The
pulley or drum is constructed with two sets of bars inclined in opposite
directions and crossing each other, and the chain lies in the V form
channel between them, and by sliding the bars of the one set past the
other the distance of their crossing points from the centre of the shaft
which carries the skeleton drum or pulley can be adjusted at pleasure.
There is another drum on the same shaft on which another chain is
wound, and it passes over a guide pulley on the jib to the load.
The action is as follows:-When water is admitted to the
hydraulic cylinder and so motion is given to the ram it unwinds the

page_text: chain from off the skeleton drum causing it to rotate, and the drum on
the same shaft is thereby rotated and caused to wind its chain upon it,
thereby lifting the load. If the loads with which the crane is working
be light the skeleton drum is so adjusted as to have a large effective
diameter, and the traverse of the ram will then be short by comparison
with the lift of the load. On the other hand if the loads be heavy the
skeleton drum is adjusted to a small effective diameter, and then the ram
will traverse over a longer distance.
When applied to hydraulic capstan engines we either place the skeleton
drum on the crank shaft or use it through the intervention of belts and
wheels, and we sometimes make the pull of the rope bring the skeleton
drum into a line with the pull.
In some cases we attain the same economy without the use of a
skeleton drum by the use of two cylinders and rams. The two rams are
arranged end to end and the hydraulic cylinders are mounted one over
the other; the smaller ram works through a stuffing box at the top of
the lower cylinder; no cup leathers are required; the water does not go
in and out of the cylinders without doing work; and only two glands are
necessary. The valves are so connected with a hand lever that the first
motion of the lever for the purpose of lifting the load admits water from
the accumulator to the upper cylinder, where it exerts an effective
pressure on the annulus, corresponding with the difference in areas of the
two rams. Should this pressure be insufficient to start the load the
lever hand is moved further, and it then shuts off the upper cylinder
from the accumulator and puts the lower cylinder in communication
with it. If in turn this should be found insufficient the lever is moved
a third step which is the full extent of its motion, and then both
cylinders will be simultaneously in communication with the accumulator
and the full power of the crane will be exerted.
In the use of ingot cranes as at present constructed a great deal of
power is wasted. In these cranes the jib or arm is mounted on the top
of the ram and is raised at every lift. Now the weight of this jib or arm
and of the ram is very great in comparison with the load of the crane,
and the power expended in lifting them is wasted. To avoid this we
place a second ram and cylinder beneath the main ram and cylinder,
and this auxiliary cylinder is placed in constant communication with
the accumulator. The auxiliary ram aids the main ram in lifting the

page_text: In order that our said Invention may be most fully understood and
readily carried into effect we will proceed to describe the Drawings
hereunto annexed.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a side elevation, and Figure 2 is a front elevation, both
partly in section, of a variable power hydraulic crane in which two lifting
rams and cylinders are employed. a, a, is the bed plate and standard
which supports the two hydraulic cylinders b and c, fixed one over the
other, and d and e are the two rams which work in these cylinders.
The rams are formed end to end, and the smaller ram only passes
through a stuffing box which is so constructed, as herein-after described,
as to prevent leakage from both the cylinders b and c. a¹ and a³ are two
water passages in the standard, the one leading into the cylinder b, and
the other by the pipe f into the cylinder c. The flow of the water by
these passages from an accumulator into the cylinders, and out of the
cylinders to the exhaust or free escape is controlled by valves which are
herein-after described. g is a ring encircling the standard a; it has fixed
to it the two standards g¹, g¹,which at their upper ends are also fixed to
the top pivot 92; 9³ is the jib of the crane fixed to the parts g and gª.
The whole of the parts marked 9 are able to rotate about the standard a
and cylinders 6 and c. On the head of the ram e is mounted a pulley h
so as to be able to turn with the parts marked g, and the standards g¹
serve as guides for the pulley has it is raised and lowered. The chain i
is made fast to the ring 9, passes over the pulley h, and then descends
to the drum k, the axes of which are carried by a bracket ¹ fixed to the
standards g¹. The drum k is of two diameters, small at one end and
large at the other end, and the chain i is attached to and wound around
it at the smaller end. Another chain is attached to and wound around
the larger part of the drum and passes away from it over the guide
pulleys on the jib to the load.
The chains are so arranged that as the pulley h is raised by the rams
and the chain i is unwound from the drum, the chain is wound up and
so the load attached to it is lifted.

page_text: In order to turn the jib and parts to which it is connected two
hydraulic cylinders and rams m, m, are employed; the rams are provided
with pulleys over which chains fixed at their ends at n, n, pass; o, o, are
guides for the rams. The chains are lapped around the drum g' which
is formed upon the ring 9, so that the advance of one of the rams m
causes the jib to swing to the right, and when this ram retires and the
other advances the jib swings to the left; p is one of the valve levers.
To prevent risk of the rams d and e being raised too high the ring q is
employed, and two long bolts q', q', pass up from it through the frame
of the pulley h and along the standards g¹. When the pulley h has been
raised as high as the heads of the bolts q¹, and nearly as high as it is
intended to allow it to rise the bolts q¹ are lifted and the ring q with
them. The flange of the ring q in rising gives motion to the lever r,
which in turn is connected with the valve which admits water into the
cylinders b and c and the motion of the lever closes the valve. Should
any leakage past the valve take place it will do no injury, for the
bolts are competent to sustain the full strain which the water can
convey.
The method of forming the stuffing box between the cylinders b and c
so that a single packed joint serves to retain the water in the two
cylinders, forms an important feature of our Invention.
The cylinders b and c are formed with flanges which are bolted
together. The cylinder at its upper end is formed as is usual with a
cavity 6* to receive packing. The cavity 6* is made so large as to receive
within it the neck c* formed on the lower end of the cylinder c, and this
neck abuts on the packing in the cavity. The neck c* is encircled
by a ring or gland
the lower end of
which is of a size to enter
the cavity. The ring is formed with flanges receiving bolts by which
the ring is forced down on to the packing and made to compress it until
the joint is fluid tight. The same arrangement of forming a neck on one
hydraulic cylinder to enter a packing cavity formed on the other side
is also applicable to double action plunger pumps.
Figure 3 is a plan and Figure 4 is an elevation partly in section of
such a pump.
a and b are the two cylinders with the single stuffing
box between them, serving to prevent the escape of water from both
cylinders where the ram c passes. The ram c receives motion from the
rod d passing through a stuffing box at the outer end of the cylinder a.

page_text: The rod d may be connected direct, as the Drawing indicates, to the
piston of a steam engine for working the pump; e is the suction, and ƒ
the delivery valve of the cylinder b.
Figure 5 is a side view, and Figure 6 an end view, both partly in
section, of the valve apparatus which we employ to work the variable
power crane; Figure 7 is a plan shewing the seating for the valves, the
valves themselves and the cover being removed. a is the inlet from the
accumulator; it is capable of being closed by the screw plug valve b,
but when the valve is open the water from the accumulator is free to
pass by the port c into the valve case d, which contains two slide valves,
one, an ordinary D valve, works over the three ports e¹, e³, e³, and the
other, which is shewn in section in Figure 5, works over the three
ports f,f,f. The ports e¹ and e³ communicate respectively with the
passages and g¹, and these are connected with the cylinders m, m,
Figures 1 and 2, which swing the crane. The port e communicates
with the exit passage h, by which the water, after it has done its work,
finds a free escape. The port e² is always covered by the D valve,
and
when the valve is so placed as to allow the water to pass out of the valve
chamber by one of the ports e¹ or e³ it allows the water to return by the
other of these ports, and so to pass to the exit h. The port f¹ leads
into the passage i, which is connected with the water passage a³ and
cylinder c, Figure 1. The port f* leads into the passage j, which is
connected with the water passage a¹ and cylinder b, Figure 1. The
port communicates with the exit passage h. The valve k, which
works over the ports f¹‚ƒ³,ƒ³, when in the position in which it is shewn
in the Drawing, admits water through the transverse groove k¹ to the
portf, and so to the cylinder c, Figure 1; the crane then works with its
lower power. A short movement of the valve to the left closes the port f¹
and the crane stops, holding the weight suspended; a further movement
to the left opens the port f' to the exit and the weight descends. On
the other hand the movement of the valve to the right causes water to
enter the port f* and pass to the cylinder 6, Figure 1, whilst the port f¹
is closed; the crane then works with its second or intermediate power.
A further movement of the valve to the right again allows water to
enter the port f¹, whilst fi is still supplied, the crane then works with
its third or highest power. The valves are moved by hand levers.
In place of the slide valve k weighted valves arranged like ordinary
safety valves may be employed: Figure 8 shews a side view of the

page_text: arrangement; Figure 9, a plan; and Figure 10, a transverse section.
The weighted valve a when lifted supplies water to the upper lifting
cylinder of the crane, and the valve 6 when lifted allows the water to
escape from this cylinder. The valve c when lifted supplies water to
the lower lifting cylinder of the crane; and the valve d when lifted
allows water to escape from this cylinder; e is an axis, on which are
formed tappets e*, and it has a hand wheel ƒ fixed upon it. The
tappets ex when the axis is turned act upon friction pulleys mounted,
as the Drawing shows, upon arms connected with the valve levers. There
are six tappets ex, and on turning the wheel, say, to the right, the first
which operates opens the valve a, the next opens b, the third opens c, the
fourth opens d, the fifth opens a and c, and the sixth opens 6 and d.
Figures 11 and 12 are longitudinal sections, and Figure 13 is a
transverse section of the skeleton drum, by means of which we obtain
variable power in hydraulic cranes, with the use of but one hydraulic
lifting cylinder. a is the axis of the drum, it is hollow, and is cast of
a piece with the end disc b. Within the axis a is a nut c; it has two
wings, one on either side, which project through slots in the axis and
connect the nut with the star form piece d; e is a screw engaging with
the nut, and when it is turned the nut, together with the piece d,
traverse along the axis; f is the other end disc of the drum ; it is fixed
upon the axis a, and the bars f¹ are cast with it; g, g, are other bars
jointed to the disc b, they are received between the arms f¹. The chain
from the hydraulic ram is attached to one of the arms g, this skeleton
drum taking the place of the drum k in Figure 1. By turning the
screw e the bars g are made to slide past the bars f¹ and to assume a
more or less inclined position, so that the crane chain beds upon the.
bars at a greater or less distance from the centre; h is the drum on
which the chain passing to the load is wound. The more obliquely the
bars g are set the greater will be the distance from the centre at which
the chain from the lifting cylinder will bed upon the bars, and the
longer the travel of the ram to lift the load a given distance the available
lifting power of the crane varies in like proportion.
Figure 14 is an elevation, partly in section, of an ingot crane
constructed according to our Invention. a and b are two hydraulic
cylinders in which the rams c and d work, and there is a single stuffing
box between the two cylinders arranged as already described. The
cylinders a and b are supported on the bed frame e, which is secured

page_text: to the foundation f. The arm of the crane, and the parts in connection
with it, are arranged and mounted in the usual manner on the head of
the ram d; g is a pipe which provides a permanent connection between
the cylinder a and the accumulator, and the pressure which is thus com-
municated to the ram c is sufficient nearly but not quite to carry the
weight of all the moving parts of the crane; h is another pipe con-
necting the cylinder 6 with valves, by which at pleasure water can be
admitted to the cylinder from the accumulator to lift the crane arm and
the load upon it, or by which water can be drawn out of the cylinder 6
to allow the crane arm to descend; during this latter motion water is 1
forced out of the cylinder a back into the accumulator.
Having thus described the nature of our said Invention, and the
manner of performing the same, we would have it understood that we
claim as our improvements in hydraulic machinery,―
First. The construction of hydrulic cranes with chain drums of 1
variable diameter, substantially as described.
Second. The construction of hydraulic cranes with two lifting
cylinders combined, so as to work separately or in unison, and yielding
variable powers, substantially as described.
Third. The arrangements in connection with the valves of a variable 2
power hydraulic crane, substantially as described.
Fourth. The means of connecting two hydraulic cylinders end to end,
so that one stuffing box around one ram serves to prevent leakage from
both cylinders, substantially as described.
Fifth. The construction of ingot cranes with an auxiliary hydraulic 2
cylinder in connection with the accumulator to compensate for the
weight of the rising and falling parts of the crane, substantially as
described.
In witness whereof, I, the said John Frederick Augustus Pflaum,
have hereunto set my hand and seal, this Twenty-fourth day of 3
August, in the year of our Lord One thousand eight hundred
and seventy-five.