Improvements in Cranes and the like.
Year: 1898

page_text: Improvements in Cranes and the like.
I, WILLIAM ROBERT GREEN, of the Newington Iron Works, Falmouth Road,
London, S.E., Engineer, do hereby declare the nature of this invention to be
as follows:-
My invention relates to improvements in hydraulic and other cranes and the
like fitted with luffing or derricking jibs and has for its object the application
of a means of balancing a portion of the weight of. the jib for the purpose
amongst others of economizing the lifting power for the jib. The apparatus
of my invention may be applied to all forms of derricking or luffing cranes and
the like and is altogether separate from the gear or apparatus by which the jib
is luffed in and out.
In carrying out one form of my invention I attach one end of a chain or rope
to the jib or arrange it so that it acts on the jib some other way and connect
the other end to a snail or volute mounted on a shaft carrying another snail or
volute fitted with a rope or chain carrying a counterweight.
This shaft is
mounted on the post or pillar of the crane or on any other convenient structure
the ropes or chains being led respectively to the jib and counterweight either
direct or over or under conveyance sheaves as may be most convenient.
In some other cases I may use only one snail or volute the other-rope being
arranged to wind on and off a plain drum, or I may use any known contrivance
other than the snail or volute to attain the same result by varying the leverage
at which the weight acts on the jib to compensate for the varying pull of the
jib as it luffs in and out; such as for instance a flat chain wrapping around a
narrow drum in superimposed layers or the like.
I may also substitute for the weight an hydraulic or other cylinder supplied
constantly with fluid under pressure.
The balancing chain may be attached to the end or other part of the jib. In
some cases I make the attachment at a point somewhere near the centre of
gravity of the jib to support it and prevent sagging, the rope connected to the
luffing gear being attached to the top.
T
1011
1
1 1900

page_text: what manner the same is to be performed to be particularly described and
ascertained in and by the following statement:—
My invention relates to improvements in hydraulic and other cranes and the
like fitted with lufting or derricking jibs and has for its object the application
of a means of balancing a portion of the weight of the jib for the purpose
amongst others of economizing the power required to lift it. The apparatus
of my invention may be applied to all forms of derricking or luffing cranes or
the like and is altogether separate from the gear or apparatus by which the jib
is luffed in or out.
In carrying out one form of my invention I attach one end of a chain or rope
to the jib or arrange it so that it acts on the jib in some other manner and connect
the other end to a snail or volute mounted on a shaft carrying another snail or
volute fitted with a rope or chain carrying a counterweight.
This shaft is
mounted on the post or pillar of the crane or on any other convenient structure
the ropes or chains being led respectively to the jib and counterweight either
direct or over or under conveyance sheaves as may be most convenient.
In some other cases I may use only one snail or volute, the other rope being
arranged to wind on and off a plain drum, or I may use any known contrivance
other than the snail or volute to attain the same result by varying the leverage
at which the weight acts on the jib to compensate for the varying pull of the
jib as it luffs in and out, such as for instance a flat chain wrapping around a
narrow drum in superimposed layers or the like.
I may also substitute for the weight an hydraulic or other cylinder supplied
constantly with fluid under pressure so as to exert a constant pull on the rope.
The balancing chain may be attached to the end or other part of the jib. In
some cases I make the attachment at a point somewhere near the centre of
gravity of the jib to support it and prevent sagging, the rope connected to the
luffing gear being attached to the top.
The accompanying drawing shows the manner in which I preferably carry
out my invention, Fig. 1 being a side elevation and Fig. 2 an end elevation of a
wall derrick or crane.
or
The jib A is "luffed"
sheaves and led away to
and lowered by a rope C.
sent invention. They may
is connected at one end e¹ to the jib and at the other to the drum E fixed to a
shaft carried by the pillar D) of the crane. The drum E is preferably made
narrow so that the rope coils thereon in superimposed layers. On the outer ends
of the shaft d are mounted two snails F having ropes f connected to the
crossbar f¹ of a counterweight G sliding on guides H fixed to the pillar D.
In some cases I attach the counterweight rope to the drum E and connect the
"snail" ropes to the jib.
derricked" in and out by a rope B passing around
be operated in any known manner.
The load is lifted
These ropes and their gear form no part of the pre-
A flat rope e
be operated in any convenient manner.
66
"
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is:-
(1.) In cranes and like apparatus fitted with luffing or derricking jibs, balanc-
ing a portion of the weight of the jib by counterweights or their equivalent
arranged to act with varying leverage or effect substantially as and for the pur-
pose described.