Improvements in Hoisting Appliances.
Year: 1897

page_text: Date of Application, 20th Jan., 1897
Complete Specification Left, 18th Oct., 1897-Accepted, 15th Jan., 1898
PROVISIONAL DE MULTIVATION.
Improvements in Hoisting Appliances.
We, GEORGE WALKER, of 95, Leadenhall Street, London, Engineer, and ALFRED
HILLYARD MITCHELL, of 95, Leadenhall Street, London, Engineer, do hereby declare
the nature of this invention to be as follows:-
In ordinary hoisting derrick pole appliances, the load is first raised to the
required height, and then it is moved round to the right or left side about its axis,
where it is fastened to the mast or pole, so that the load may be deposited to either
side of the place lifted. This motion is generally performed by manual labour,
by acting on the end of the jib.
If the load is required to be lifted from or deposited at a spot, nearer to er
farther away from the mast or pole, the derrick pole or jib, has to be raised or
lowered.
According to this invention, we provide a means of slewing or moving the load
to the right or left, other than that mentioned above, and also we provide a means
of travelling the load in or out, so as to bring it nearer to, or take it further away
from the mast or pole, other than that of lifting or lowering the derrick pole or
jib; and both these motions can be performed at certain angles of inclination
of the jib or derrick pole.
For the purpose of slewing or swinging the load to the right or left, a crosstree
is fixed to the mast or pole, or to the jib or derrick pole, and chains led from the
end of the jib, or any intermediate part, over pulleys on the ends of the crosstree,
and then over a drum which is coupled to and driven by worm and worm wheel,
or cog and pinion wheel gearing.
When the drum revolves it takes up chain on one side, and pays it out on the
other, thus moving the jib about its axis.
Or a right and left handed screw, similar to those used for steering gears, is
fixed to the mast or pole, or to some other convenient part, and the chains led from
the travelling nut over the pulleys as aforesaid, or coupled direct.
Or the right and left handed screw may be fixed to the jib itself, and the ends
of the rods which are connected to the travelling nuts, are fastened to the cross-
tree on the mast or post, so that if the screw be turned it swings the jib to the right
or left, travelling with the jib itself in so doing.
All the gears mentioned above may be driven from the winch, or by separate
motive power such as, an electro motor, seperate steam, gas, oil, or air engines,
and may be either coupled direct or by gearing.
The slewing can also be accomplished by a hydraulic ram or rams, acting in such a
manner that whilst one takes up the chain, or pushes or pulls the jib over to one
side; the other is allowing the necessary amount of chain to pay out, or the jib
to make the necessary movement, by exhausting itself whilst the other ram" is
acting or filling; and these rams can be either fixed direct to the jib, or coupled
by means of suitable gearing, they being fixed on the floor, or any convenient
place

page_text: For the purpose of travelling the load nearer to or further away from the mast
or pole, we pass the lifting chain over a traveller, which traveller is made to move
along the jib. To keep the load at the same distance from the jib, and make it
travel parallel to it, a compensating block is introduced into the circuit of the
lifting and compensating gear chains.
The essential part of this block consists of two wheels fastened in one frame,
the lifting chain passing over the one, and the pulling out chain over the other.
The lifting chain being led over the wheel in the block, is carried back over a
pulley which is fixed at the end of the jib, so that the doubled lengths of chain
may be as nearly as possible parallel, and from there it passes over the wheel in
the traveller.
The gear or compensating chain, is fastened to the outer end of the traveller,
passes over a pulley at the outer end of the jib, is carried over the second wheel in
the compensating block, and is fixed at a point near to the end pulley, so that the
doubled lengths of chain may be as nearly as possible parallel.
A pulling in and out chain is, for more conveniently travelling the load, fixed
to the inside end of the traveller, passes over a guide pulley to bring it as nearly
as possible parallel to the lifting chain, over the winch or motive gear, back over an
additional pulley fixed in the compensating block, and is fixed at a point near the
inner end of the jib, in such a manner that the doubled lengths of chain may be
as nearly as possible parallel.
If this pulling in and out chain be moved so as to pull the traveller towards the
mast or pole, it will cause the block to travel in the opposite direction, or if the
block be pulled in towards the mast or pole, the traveller will move outwards, due
to the pull of the compensating gear chain, which by transmission of power
through the block becomes a pulling out chain.
In each case the block travels half the distance of the traveller, but it so pays out
and takes up the lifting chain that the load moves along the jib at the same
distance from the jib as it was originally lifted, and travels parallel to it.
Dated this 20th day of January 1897.
GEO. WALKER.
ALFRED HILLYARD MITCHELL.
Improvements in Hoisting Appliances.
We, GEORGE WALKER, of 95 Leadenhall Street, London, Engineer, and
ALFRED HILLYARD MITCHELL, of 95 Leadenhall Street, London, Engineer, do
hereby declare the nature of this invention and in what manner the same is to
be performed, to be particularly described and ascertained in and by the follow-
ing statement:
-
In ordinary hoisting derrick pole appliances, the load is first raised to the
required height, and then it is moved round to the right or left side about its axis
where it is fastened to the mast or pole, so that the load may be deposited on either
side of the place lifted.
This motion is generally performed by manual labor, by acting on the end of
the jib.
If the load is required to be lifted from, or deposited at, a spot nearer to, or
further away from the mast, or pole, the derrick pole or jib has to be raised or
lowered.
According to this invention we provide a means of slewing or moving the load
to the right or left, other than that mentioned above, and also of moving the ivad

page_text: nearer to or further away from the mast, other than that of lifting or lowering the
jib, and both these motions can be performed at certain angles of inclination of
the jib.
For the purpose of slewing the load we provide apparatus as shewn in
Figures 1, 2, 3, 4 and 5 which we will now proceed to describe.
In Figures 1 and 2 W is a worm wheel attached to a barrel B, or B can be
replaced by a gipsy wheel when desirable. W is driven by a worm O which is driven
by a driving wheel I worked by a messenger chain from the winch, or by other
gear. C is a chain connected to the jib and guided from there round pulleys PPI
and then over the barrel B. P and P1 may be fixed at any convenient part of the
ship such as the bulwarks or deck or rigging or to a spar or crosstree suspended
from or fixed to the mast or rigging. When W is made to revolve it will wind
in C on one side and pay it out on the other and in so doing since C is fastened to
the jib, it will be slewed to the right or left.
Figure 3 is a plan in which M is the mast J the jib and J is at right angles to
a crosstree or levers marked C and fixed on the mast or other convenient place.
F is a fulcrum or pivot on which J swings.
Figure 4 is another plan shewing J slewed to the left. S is a right and left
handed screw each being the same length and pitch meeting at B which is sup-
ported by a bearing if necessary. B and B are end bearings by which the screw
is fixed to the jib. Attached to some convenient part of S is a gipsy wheel or
other gear, by means of which it can be made to revolve.
N and N are nuts, one fitted to each screw, which when S revolves, move along
it, away from or towards each other according to the direction of rotation. Gi
and G2 are guide rods to keep the nuts from turning with the screw and to reduce
the strain upon S. From the ends of these travelling nuts N¹ and N2, connecting
reds Rand R2 are led to points 1 and P2 on C. The centre points of these con-
nections are all at an equal distance from the centre line of the screw when the
jib is at right angles to C. When S is made to revolve the nuts N¹ and N² travel
along it and because M and C are fixed the jib J is swung to the right or left.
If so desired the screw gear can be fitted vertically to the mast the nuts N¹ and N
being connected by chains and pulleys or by levers or rods to any convenient part
of the jib.
In Figure 5, C is a crosstree fixed as in Figure 4 described above, M is the mast
J the ji R and R2 are hydraulic cylinders pivoted on the crosstree C at P¹
and their other ends being fixed at and F2 The supply and exhaust valves
are so arranged that when one is open the other 1S closed and also
SO that both may be closed at once, but both cannot be opened at
once. When water is admitted to R the ram will be forced out
moving the jib over, and the Ram of R2 will be forced in. If water is admitted
to Re the opposite effect will be produced. The cylinders may also be fitted on the
mast or to the deck the rams being connected to J by pulleys and chains, or rods
or levers suitably placed, or they may be fixed to the jib, the rams acting on P
and in the opposite way to that shewn in the drawing.
For the purpose of moving the load in or out a compensating block B consisting
of % wheels in I frame is used as shewn in Figure 6. Or this may consist of two
separate single blocks joined together.
In Figure 7 M is the mast, J the jib, B is the block containing 2 wheels B₁
and B. P, P2, P3, are pulleys, T is a traveller with wheels for travelling along the
jib. G is a gear chain with one end fixed at F. From there it is carried
round B over P2 which is fixed on the mast so as to bring the two strands of chain
as nearly as possible parallel, then over P3 fixed at the end of the jib, and is
fastened by its other end to the traveller T. H is the lifting chain, it is brought
from the hoisting gear over B2 down under P so that the two strands be parallel
as above, and it is then taken over the wheel of the traveller T, the load being
suspended at L. A third chain for moving the traveller along the jib, and
marked X is fixed by one end to T, carried over P4 over a gipsy wheel or barrel G,

page_text: up over another pulley attached to or fitted in the block and marked B³ and its
other end fixed to any convenient part say F².
If G be made to revolve it will move X over it pulling down B or pulling in T
according to the direction of rotation. Provided H be fixed at the hoisting gear,
since the amount paid out on the one side of B is equal to the amount taken up
on the other, the load which is suspended at L will be moved in or out parallel
with the angle of inclination of the jib.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is:
1. To swing the jib or boom of hoisting appliances from one side to another by
mechanical means substantially as described and shewn in the drawings hereunto
annexed and marked Figures 1, 2, 3, 4, and 5.
2. To lift and lower weights attached to hoisting machinery, and to move the
same in or out along the jib, by means of travelling carriages, in a line parallel
to the jib by means of a compensating block and gear substantially as described,
and shewn in the drawings hereunto annexed, and marked Figures 6 and 7.
Dated this 18th day of October 1897.
GEO. WALKER.
ALFRED HILLYARD MITCHELL.