IMPROVEMENTS IN CRANES TO BE WORKED BY HYDRAULIC OR OTHER POWER
Year: 1877

page_text: LETTERS PATENT to George Low, of Ipswich, in the County of Suffolk, for
the Invention of "IMPROVEMENTS IN CRANES TO BE WORKED BY HYDRAULIC
OR OTHER POWER."
Sealed the 13th June 1878, and dated the 21st December 1877.
PROVISIONAL SPECIFICATION left by the said George Low at the Office of
the Commissioners of Patents on the 21st December 1877.
GEORGE LOW, of Ipswich, in the County of Suffolk.
TO BE WORKED BY HYDRAULIC OR OTHER POWER."
**IMPROVEMENTS IN CRANES
This Invention has for its object improvements in cranes to be worked by
hydraulic or other power. I construct such cranes with a jib moveable about an
horizontal axis, so that it can travel through the vertical from one side to the other
of its standard or support. This motion is given to the jib by connecting it with an
hydraulic press, to the cylinder of which water under pressure is admitted by a
valve.
The valve is controlled automatically by instruments in connection with the jib,
and operating, so that the valve, having been opened by hand to admit water to
the press, and raise the jib with the load attached to it as the jib passes the vertical,
the supply passage is automatically closed, and the exhaust opened, so as to
allow the jib to descend on the other side; and when the jib has reached the point to
which the apparatus has been previously set, the exhaust is in turn closed, and the
water being imprisoned in the cylinder of the press the jib is brought to rest.
The valve which I employ is a disc held by the pressure of the supply against a
face, in which are passages leading into a chamber open at all times to the cylinder
press. The valve disc has a hollow stem passing out of the valve box through a
stuffing box, and receiving a handle by which the valve can be turned. The
sectional area of the valve stem is such as to adjust suitably the pressure of
the valve on the valve face. The exhaust takes place through the stem of the
valve which is in communication with the exhaust passages in the face of the disc.
CD 1071

page_text: The valve works through an arc of somewhat less than half a circle, its play being
limited by stops
When the valve is at either end of its course, the supply is open to the cylinder of
the press. At two intermediate points the valve closes entirely the passages leading
to the cylinder, and when the valve is in its central position, the exhaust from the
cylinder is full open. The stem of the valve has upon it two tappet arms, and on
the same axis with the jib of the crane there are three arms or wipers.
The action of these parts is as follows:-In order to raise the jib with its load, the
valve is moved by hand to one or other of its two extreme positions, according to the
side on which the jib happens to stand at the time. Thus the jib is brought to the
vertical position, and one of the arms or wipers moving with the jib strikes the tappet
or arin on the stem of the valve, and moves the valve at once to its central position,
thereby opening the exhaust and permitting the motion of the jib to be continued
by its own weight until another of the arms or wipers upon the axis of the jib
comes round, and in a similar manner moves the valve further, thereby closing the
passages leading to the cylinder, and stopping the further motion of the jib.
To cause the return of the jib, the valve is moved a step further in the same
direction, and the automatic actions repeat themselves; first, when the jib reaches
the vertical position, the central wiper causes the exhaust to be opened, and after-
wards when the jib has descended sufficiently far the other outer wiper (which in
the previous stroke was inoperative) sets the valve, so as to close the cylinder of
the press, preventing the escape of the water from it, and so bringing the jib to
rest.
There is a relief valve to prevent the cylinder being exposed to undue strains,
and permitting the water to pass back to the supply valve when the pressure in
the cylinder exceeds that in the supply pipe. A valve in the exhaust passage serves
to regulate the speed of motion.
For the purpose of raising and lowering independently of the movement of the
jib, the crane is supplied with another hydraulic press, which actuates a pitch
chain gearing with a pinion, the axis of which is carried upon the jib. On the
same axis there is also a drum, upon which the crane chain is wound, and the chain
passes from the drum over guide pulleys on the jib head to the load. The size of
the drum is such as to multiply to the desired extent the motion of the pitch chain;
the chain is led from the drum on the side of the axis on which the pitch chain
operates upon the pinion. The arrangement at the jib head is such as to admit of
the load swinging clear as it passes from side to side.
In some cases I make one hydraulic press serve for lifting the load and for
swinging the jib. I connect the ram by a chain passing between guide pulleys on
the lower end of the jib, with a small drum on the same axis with the drum on
which the lifting chain is wound. The first part of the movement of the rain draws
the chain off the small drum, and winds up the lifting chain; and this being done,
the ram acts through the same chain to draw the jib to a vertical position.
Cranes similar to those herein described may be operated by steam or other
fluid; for steam I employ larger and jacketted cylinders, and make provision for the
escape of condensed water.
I also apply a self-acting pawl, or catch, or an hydraulic controlling cylinder to
control the motion of the apparatus.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said George Low in the Great Seal Patent Office on the 21st June
1878.
GEORGE LOW, of Ipswich, in the County of Suffolk.
TO BE WORKED BY HYDRAULIC OR OTHER POWER."
"IMPROVEMENTS IN CRANES
This Invention has for its object improvements in hydraulic cranes.
I construct
such cranes with a jib moveable about an horizontal axis, so that it can travel
through the vertical from one side to the other of its standard or support. This
motion is given to the jib by connecting it with an hydraulic press to the cylinder,
of which water under pressure is admitted by a valve.
The valve is controlled automatically by instruments in connection with the jib
(the valve having been opened by hand to admit water to the press, and raise the jib
with the load attached to it). When the jib passes the vertical the supply passage is
automatically closed, and the exhaust passage is opened (so as to allow the jib to
descend on the other side). When the jib has reached the point to which the
apparatus has been previously set, the exhaust is in turn closed, and the water
being imprisoned in the cylinder of the piess, the jib is brought to rest.
The valve which I employ is a disc held by the pressure of the supply against a
face, in which are passages leading into a chamber open at all times to the cylinder
of the press. The valve disc has a hollow stem passing out of the valve box through &
stuffing box, and receiving a handle by which the valve can be turned. The sectional
area of the valve stem is such as to adjust suitably the pressure of the valve on the
valve face. The exhaust takes place through the stem of the valve, which is in
communication with the exhaust passages in the face of the disc The valve works
through an arc of somewhat less than half a circle, its play being limited by
stops.
When the valve is at either end of its course, the supply is open to the cylinder
of the press. At two intermediate points the valve closes entirely the passages
leading to the cylinder, and when the valve is in its central position, the exhaust
from the cylinder is full open. The stem of the valve has upon it two tappet
arms, and on the same axis with the jib of the crane there are three arms or
wipers.
The action of these parts is as follows:-In order to raise the jib with its load,
the valve is moved by hand to one or other of its two extreme positions, according
to the side on which the jib happens to stand at the time. Thus the jib is brought
to the vertical position, and one of the arms or wipers moving with the jib strikes
the tappet or arm on the stem of the valve, and moves the valve at once to its
central position, thereby opening the exhaust, and permitting the motion of the jib
to be continued by its own weight until another of the arms or wipers upon the
axis of the jib comes round, and in a similar manner moves the valve further,
thereby closing the passages leading to the cylinder, and stopping the further
motion of the jib.
To cause the return of the jib the valve is moved a step further in the same
direction, and the automatic actions repeat themselves; first, when the jib reaches
the vertical position, the central wiper causes the exhaust to be opened, and after-
wards when the jib has descended sufficiently far, the other outer wiper (which in
the previous stroke was inoperative) sets the valve, so as to close the cylinder of
the press, preventing the escape of the water from it, and so bringing the jib to
rest.
There is a relief valve to prevent the cylinder being exposed to undue strains,
and permitting the water to pass back to the supply when the pressure in the
cylinder exceeds that in the supply pipe. A valve in the exhaust passage serves to
regulate the speed of motion.

page_text: For the purpose of raising and lowering, independently of the movement of the
jib, the crane is supplied with another hydraulic press, which actuates a pitch
chain gearing with a pinion, the axis of which is carried upon the jib. On the same
axis there is also a dṛum, upon which the crane chain is wound, and the chain
passes from the drum over guide pulleys on the jib head to the load. The size of
the drum is such as to multiply to the desired extent the motion of the pitch
chain, the chain is led from the drum on the side of the axis on which the pitch
chain operates upon the pinion. The arrangement at the jib head is such as to
admit of the load swinging clear as it passes from side to side.
In some cases I make one hydraulic press serve for lifting the load and for
swinging the jib. I connect the ram by a chain passing between guide pulleys on
the lower end of the jib with a small drum on the same axis with the drum on
which the lifting chain is wound. The first part of the movement of the ram draws
the chain off the small drum, and winds up the lifting chain, and this being done,
the ram acts through the same chain to draw the jib to a vertical position.
Cranes similar to those herein described may be operated by steam or other fluid;
for stoam I employ larger and jacketted cylinders, and make provision for the
escape of condensed water.
I also apply a self-acting pawl, or catch, or an hydraulic controlling cylinder to
control the motion of the apparatus.
In order that my said Invention may be most fully understood and readily
carried into effect, I will proceed to describe the Drawings hereunto annexed.
A second position of the crane jib is indicated in dotted lines.
Figure 2 is a side elevation of the jib head.
Figure 3 is a sectional fiont elevation of the crane
Figure 4 is a front elevation of the jib head.
Figure 5 is a plan with some of the upper parts removed; and Figure 6 is a 3
portion of a side elevation, showing especially the arrangement of the controlling
arms or wipers.
Figure 7 shows a longitudinal section of the valve and the parts in connection
therewith; Figure 8 is a fiont elevation, partly in section, of the same.
The upper
part of the valve, as represented in Figure 7, is a section taken on the line A, B, in 3
Figure 8; and the lower part of the valve, as represented in Figure 7, is a section
taken on the line B, C, in Figure 8.
Figure 9 is a plan.
Figure 10 shows the valve seat.
Figure 11 is also the valve seat with the valve, represented partly in section, 4
resting upon it.
Figure 12 is a plan of the levers by which the valve is moved, and in the same
Figure the arms or wipers for moving them are represented in section. These
Figures are drawn to the full size or thereabout.
The crane has a double jib A with two gudgeons B, B, which work in bearings 4
in the frames C, C, placed on each side, and which are bolted to a turntable D (or
it may be on a hollow column working on a footstep) when a slewing motion is
required; but when not required, the aforesaid frames C, C, are bolted to a simple
holding-down plate Immediately below the fulcrums of the jib, and in bearings cast
on the turntable or plate (or it may be inside a hollow column), the trunnions 5
F, F, of the hydraulic cylinder E work, allowing the cylinder to oscillate. The

page_text: piston rod G is attached to the lower end of the jib by two links g, g; these press
on flanges h, h, cast on jib frame in order that the full leverage may be obtained
when the jib is at the lowest point.
The water pressure is admitted from the self-acting equilibrium valve through
one of the trunnions F,F, which oscillates on the pipe by a cupped leather swivel
joint. The piston when moved in turn pulls the jib up to a vertical point, when by
means of the self-acting valve the water is turned off, and the exhaust opened simul-
taneously, allowing the jib to descend down on other side till arrested at any
desired point.
On the outside of one of the A frames the improved self-acting equilibrium four-way
valve N is fixed; this valve is fully shown in the full sized figures, and consists of
a disc O revolving against the face in valve box. In the valve box face are two
openings P, P, radiating from the centre, and in the valve disc are two double inlet
ports QQ, and two exhaust ports R, R; these are so placed that the inlet, exhaust, and
stop can be obtained whichever direction the jib turns over on the valve disc O, and
in one piece with it is the exhaust pipe p, which also acts as spindle, it is carried
through the valve box in cup leather bearings. The diameter of this spindle is so
proportioned as to leave a small extra area on the valve disc in order that the latter
inay be kept up to its face with a small portion of the pressure. The valve is by
this means equilibriated, and is thus relieved from injurious pressure. On the
spindle are keyed two levers S, S, on each of which there is a roller s. One of these
levers is lengthened beyond the roller, and bent to serve as a handle.
A face plate T carrying three striking arms or wipers t, t', t", is keyed on one of
the gudgeons of jib; the middle one t¹ is a fixture, and plumb with the jib; it is
wide enough to strike on either lever S, S, of valve to open the exhaust when the
jib transits over the vertical point. The two outside arms t, (1, are to stop the
jib by closing the exhaust. One of these arms is to act with the jib moving in one
direction on its corresponding valve lever, and the other with the jib moving in the
reverse direction on its corresponding valve lever. These arms are fastened by bolts
and nuts in the circular groove of face plate in any part, according to where it is
desired to stop the jib. The action of the arms is indicated in Figure 6.
Moving the hand lever of the valve outward against either stop (according to the
position of the jib) opens the inlet, admitting the water at the top of the hydraulic
piston, and pulling the jib up to a vertical point. The middle arm t¹ then strikes
one of the valve levers, shutting the inlet, and opening the exhaust almost simul-
taneously. The jib is thus allowed to descend on the other side until arrested by
the following arm t or t" (which are somewhat longer than t'), striking the lever, and
moving the valve another step round, so shutting the exhaust and holding the
jib. When it is desired that the jib should return, this is brought about by moving
the hand lever still further until it comes against the other stop; the water is
now again admitted to the cylinder E, moving the jib in the opposite direction with
the same result as described above.
A very slight momentum of the jib is sufficient to carry it over the extreme
dead point, or the period of closing the inlet and opening the exhaust.
The exhaust water escapes through hollow spindle of the valve, and through four
holes into a chamber formed in the cover of the valve case, and from this chamber
into a pipe leading into the tank of accumulator pump, so that the water may be
used over again, a regulating cone tap may be placed in the outlet pipe to regulate
the speed of the descent of the jib.
A second hydraulic cylinder K is placed between the cheeks of the double jib
below the fulcrums, and is bolted inside a hollow cast-iron frame, which connects
the two cheeks together and carries the fulcrum gudgeons. The piston rod is
attached to a pitch chain L working upon a pitch chain wheel pulling it round,
and with it a drum M of, say, three or more times its diameter to increase the
stroke of the cylinder to the load chain, which is wound on and unwound from the
barrel to bring the bucket to any desired distance from the end' of the jib. .

page_text: The cylinder K is worked from another equilibrium hydraulic valve X similar to
that described, but used in this case as a two-way valve, and moved by hand.
It admits the water through one of the gudgeons to the upper part of hydraulic
cylinder. This valve box is attached by a swivel-cupped leather joint inside the
end of the gudgeon, allowing the latter to revolve with the movements of the jib.
The bucket or load chain passes up the side of one of the cheeks of the jibs over a
pulley placed at right angles, and down between two pulleys on the transit line;
this is to allow the bucket to swing from one side to the other when the jib transits
over the vertical point, and clear the up chain. When a single jib is used the chain
passes through a hollow swinging projecting point, turning round with the bucket
or load when the jib transits over the vertical point.
Figure 13 is a side elevation, and Figure 14 is a front elevation of a transit
crane in which one cylinder serves both to work the jib and to wind and unwind
the load chain. The arrangement here shown is adapted for steamers and ships,
more especially such as trade to ports devoid of crane accommodation. It is
particularly adapted for unloading ships into lighters, or for loading them from
Lighters.
A is the power cylinder; within it works an inverted ram B, and chains C pass
from the ram between the guide pulleys D, D, on the frame, and over other pulleys
E, E, on the jib to small drums F, F, from which the ram unwinds the chains as it
descends. The drums F, F, turn upon the axis carrying the jib, and they are fast
with the larger drum G, upon which the load or bucket chain is wound to raise the
bucket or load.
When the crane is in operation the first portion of the stroke of the ram raises
the bucket or load to the jib head, as the drums will turn upon the axis of the jib
with less strain than is required to raise the jib. On the descending side moveable
stops are provided to receive the jib, they are set to the position in which the jib
is stopped by the closing of the exhaust passage, and when the jib is thus supported
the load chain can be allowed to unwind by re-opening the valve.
Figure 15 is a side elevation; and Figure 16 is a front elevation of a similar crane
specially adapted for use in warehouses; the power cylinder in this case is arranged
in an horizontal position
In many cases it will be advantageous to provide for the supply of these cranes
with water at two or three different degrees of prossure, say, a heavy pressure, such
as 700 pounds to the inch for doing the heavy work; a pressure of about half the
amount, or 350 pounds, for doing the light work; and a third pressure, such as
can be obtained from a stand pipe, or clevated cistern, for moving the crane when
unloaded.
Cranes such as those herein described may be worked by steam pressure, in which
case the power cylinder being made of suitable size I place one or two hydraulic
cylinders on the side or sides of the steam cylinder, and the three piston rods I
connect to one cross head. The hydraulic cylinders have a connection from one end
of the cylinder to the other, and in this connection or passage there is a tap or
valve worked in unison with the main valve, and closing with it, but standing open
whenever the main is open either for steam or exhaust.
When employing steam I provide for the escape of water resulting from con-
densation by fitting a valve, which, when the ram is moving into the cylinder
during the time of exhaust, is held back off its scat by means of a frictional con-
nection with a stationary part, which, when the movement of the ram is in the
other direction, the valve is returned to its seat.
Having thus described the nature of my said Invention and the manner of per-
forming the same, I would have it understood that I claim,―
First. The construction of a crane with a jib mounted upon an horizontal axis,
and actuated by an hydraulic or other power cylinder, and ram (or their equivalents),
acting upon the jib either directly, or through a chain or other connection, sub-
stantially as described.

page_text: Second. The means for automatically arresting the supply of water or other fluid
to and permitting its escape from the power cylinder as the jib passes its highest
position, and for arresting the escape or passage of fluid when it is required that the
jib should be brought to rest, substantially as described.
Third. The construction of cranes, substantially as described and represented in
the annexed Drawings.
In witness whereof, I, the said George Low, have hereunto set my hand and
seal, this 19th day of June, in the year of our Lord One thousand eight
hundred and seventy-eight.
GEORGE LOW. (L.S.)