IMPROVEMENTS IN STEAM CRANES
Year: 1867

page_text: LETTERS PATENT to George Russell, of Glasgow, in the County of
Lanark, Engineer, for the Invention of "IMPROVEMENTS IN STEAM
CRANES."
Sealed the 26th July 1867, and dated the 1st February 1867.
PROVISIONAL SPECIFICATION left by the said George Russell at the
Office of the Commissioners of Patents, with his Petition, on the
1st February 1867.
I, GEORGE RUSSELL, of Glasgow, in the County of Lanark, North Britain,
Engineer, do hereby declare the nature of my said Invention for "IMPROVE-
MENTS IN STRAM CRANES," to be as follows:-
This Invention relates to steam cranes which have gearing for swinging
ór sluing the crane by means of steam power, and has for object to prevent
breakages or accidents by arranging the sluing gear in such a manner that
should the jib or other part of the crane be obstructed while in process of
sluing the crane may cease to swing, while at the same time the engines or
motive power continues in motion, and also, that when the sluing motion is.
put in gear with the motive power the crane will start gradually and not be
suddenly jerked.

page_text: In carrying out this Invention according to one modification two revolving
shafts, which are part of the sluing gear, are connected together by an endless
chain or band working on suitable pulleys, one pulley on each shaft. The
power is thus communicated by the friction of the chain or band on the
pulleys. The chain or band is by preference adjusted to any required degree
of tension by means of weights. Springs or other equivalents applied to
either or both of the pulleys, or an intermediate moveable adjustable pulley
may be applied to the chain or band for the same purpose; as little, power is
required to swing a crane the chain or band is so adjusted that it will slip on
one or both of the pulleys whenever the crane is prevented from sluing while
the sluing motion is in gear.
This Invention may also be applied to cranes not worked by steam,
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said George Russell in the Great Seal Patent Office on the
29th July 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
RUSSELL, of Glasgow, in the County of Lanark, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the First day of February, in the year of our Lord One
thousand eight hundred and sixty-seven, in the thirtieth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
George Russell, Her special licence that I, the said George Russell, my
executors, administrators, and assigns, or such others as I, the said George
Russell, 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 berein 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 STEAM
CRANES," upon the condition (amongst others) that I, the said George Russell,
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 Russell, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement in writing, reference being had to the accompanying Drawings,
and to the letters and figures marked thereon, that is to say:-
My said Invention relates to steam cranes, and also to cranes which are
moved by any other power, which swing or slew the load in a circle by means
of gearing, and has for object to prevent breakages or accidents by arranging
the slewing gear in such a manner that should the jib or other part of the
crane be obstructed while in process of slewing the crane may cease to swing,
while at the same time the engines or motive power continue in motion, and
also that when the slewing motion is put in gear with the motive power the
crane will start gradually and not be suddenly jerked.
And in order that my said Invention and the manner of performing the
same may be properly understood, I have hereunto appended a Sheet of
explanatory Drawings, shewing two modifications of my Invention.
Figure 1 is a side elevation, and Figure 2 is a ground plan (the portion of
plan, Figure 2, at. the right-hand side of centre line being in section) of the
principal parts of a steam crane constructed according to one modification of
my Invention.
B is the boiler; C, the cylinders of engines. Rotary motion is com-
municated from the engine shaft to the shaft on which is placed the hoisting
barrel L by a spur wheel and pinion; on this spur wheel a grooved pulley D,
such as shewn in Figure 5, is fixed, so that the grooved pulley and spur wheel
always revolve together. A clutch. M, moved by suitable levers or other
means, engages or disengages the hoisting motion; an endless chain connects
the pulley D with the pulley E, and communicates a rotary motion; a
clutch N, moved by suitable levers or other meaus, engages or disengages the
worm shaft O. with the pulley E. When it is required to swing or slew the
crane the clutch N is put in gear with the pulley E, which causes the worin
O to revolve, and being in gear with a suitable worm wheel P fixed on central
pillar the crane revolves at a reduced speed. A moveable bar H carrying
a pulley G may be used for adjusting the endless chain F to any required
degree of tightness in order to communicate sufficient power to overcome the
friction of swinging the crane. This pulley G may be kept in contact with
the chain F by means of one or more springs, weights, or other equivalents,
or, as shewn in the Drawing, one end of the bar H may be screwed and
adjusted by means of a nut or nuts pressing against one of the standards which
support the bar H.

page_text: Figure 3 is a side elevation, Figure 4 a ground plan, and Figure 6 a cross
section of the principal parts of a crane constructed according to another
modification of my Invention. The power is communicated for hoisting and
swinging the load from a rotating shaft in fixed bearings to a revolving jib.
A rotating shaft has a barrel Land a grooved pulley D placed on it, the shaft
being free to revolve, while the barrel L and pulley D remain stationary.
A double clutch N fixed by a key so as to revolve with the shaft, but free to
move longitudinally, is moved by levers or other suitable means so that it can
be made to engage either the barrel L or the pulley D. When the pulley D
is made to revolve the rotary motion is communicated through the endless
chain F to the pulley E.and the worm O, which gears with a worm wheel
fixed on the mast or bottom socket of the mast R of crane, which causes the
mast and jib of crane to revolve. The box Q, which forms the sole or support
for the mast, has within it a pulley S which guides the hoisting chain A from
the barrel L vertically up the centre line of the mast to the top, when it leads
over another similar pulley to pulley at upper end of jib in the usual manner.
The mast is formed with a suitable space to allow chain A to work perfectly
vertical, so that in slewing the length of the chain from pulley S at bottom
to the pulley, at top will remain constant. The barrel L must have a friction
or ratchet wheel or some equivalent, so that the load may be fixed suspended
while slewing. Rotary motion may be communicated to the barrel shaft by
other means than steam power, such as manual or hydraulic power, when
the endless chain F acts horizontally or nearly so, the weight of the chain is
found in practice to be sufficient to communicate the necessary power for
slewing without any arrangement for adjusting or tightening.
In either of these two arrangements or modifications of my Invention other
forms of gearing could be substituted for the worm and wheel to reduce the
speed; the endless chain F could also be adjusted by arranging one or both
of the pulleys with a moveable axis. The chain may be of any form of link,
such as is commonly used for hoisting chains in cranes, or a band or cord of
any convenient section may be employed.
Having thus particularly described my said Invention, and the manner in
which the same is or may be performed, I have to state that I do not restrict
myself to the precise details herein described or delineated; but that what I
believe to be novel and original, and claim as the Invention secured to ine
by the herein-before in part recited Letters Patent is, the improved method of
communicating the power for swinging or slewing the jib of a crane by an
endless chain or band working on pulleys in such a manner that the chain or
band will slip on either or both of the pulleys should the jib or crane

page_text: become obstructed while swinging or slewing substantially as herein-before
described.
In witness whereof, I, the said George Russell, have hereunto set my
hand and seal, this Twenty-sixth day of July, in the year of our Lord
One thousand eight hundred and sixty-seven.
Witness,
JOHN GRIEVE,
Engineer,
Motherwell,
N.B.
GEORGE RUSSELL. (L.B.)