Motive Power to Cranes, Sheer Legs, and the like.
Year: 1888

page_text: Motive Power to Cranes, Sheer Legs, and the like.
I RICHARD RICHARDSON HUTCHINSON of 114 Edith Grove, Brompton London S.W.
Electrical and Mechanical 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 following statement :-
The object of my Invention is the application of a current of electricity as a motive
power, to cranes, sheer legs, and similar contrivances employed for lifting and moving
heavy weights, said electric current being derived from any convenient source, either
in the proximity of said crane or the like, or at any distance from the same.
In order that my Invention may be clearly understood reference may be made to
the accompanying sheet of drawings in which Figure 1 represents an elevation of an
ordinary jib crane with an electric motor attached thereto. Figuro 2 is a plan view
of the same, and Figure 3 is an end view of a double geared crane for lifting and
moving very heavy weights.
In carrying out my Invention, and applying same to an ordinary jib crane,
Figures 1, and 2, I attach an electric motor a to the frame thereof, in such a manner
that a pinion c keyed or otherwise fixed to the motor spindle, may gear with the spur
wheel 6 upon the chain barrel e, A current of electricity being caused to traverse
the coils of the motor a will thus actuate the chain barrel e by means of pinion c and
spur wheel b, and either wind the chain upon said barrel e, and thus raise the weight
suspended to it, or unwind said chain and lower the weight aforesaid-Motion in
either direction may be effected by reversing the motor, either by reversing the
angle of commutation, a suitable brush holder and hand gear being provided for the
purpose, or by reversing the direction of the electric current through the field
imagnets, thereby changing the magnetic polarity of the latter relatively to that of
the armature, this being accomplished by means of a suitable switch, in both cases
however the regulating appliance is placed so as to be readily accessible to the
attendant in charge of said crane, or other lifting apparatus. I further provide a
sleeve clutch, operated by the handle d for disconnecting the electric motor a from
the barrel e when desired-In the jib crane illustrated by Figures 1 and 2 I have
shown an ordinary strap brake, actuated by the pedal i but I may substitute for this
or any other mechanical brake, an electro-magnetic brake or I may provide, in con-
nection with the electric motor, a set of resistance coils, so that when the weight

page_text: suspended from the crane is to be lowered the electric current passing through the
motor may be regulated in such a manner that the armature fulfils the functions of
a brake.
Figure 3 shews the method adopted by me when applying my Invention for the
purpose of actuating larger and more massive cranes than those referred to in the
foregoing example-The electric motor a is attached, as before, to the frame, and two
pinions c and c are supported by the spindle thereof, so that they may freely revolve
independently of said spindle, being controlled by a. sleeve clutch sliding upon a
feather on said spindle, and operated by the lever d so as to engage with the clutch
jaws upon either pinion. The pinion c gears directly with the spur wheel upon the
chain barrel e, and the other pinion cl with a second spur wheel g upon a counter
shaft, which, when the clutch is engaged with the pinion e drives the barrel e by
reason of the pinion gearing with the spur wheel b. In this manner I am enabled
to revolve the barrel e by the electric motor a either quickly, with small leverage, for
small weights, or slowly with greater leverage, for heavy weights. I may also by
means of suitable gearing, cause the crane to revolve upon the central pillar h,
raise or lower the jib thereof, by means of the electric motor, and may use either an
electro magnetic brake, or cause the motor to act as such, as hereinbefore described or
may employ any suitable type of mechanical brake-In cases where such a crane is
mounted upon wheels for moving, loaded or otherwise, upon a suitable track, I
provide gearing so as to produce such motion from the spindle of the electric
motor.
or may
When applying my Invention to sheer legs, I employ the hauling gear, as shewn by
Figure 3 for actuating the chain, but may provide a second electric motor for raising
the legs, or connect the screw, or other appliance used for this purpose, by means of
suitable gearing, to the electric motor used for hauling.
In cases where my Invention is applied to a travelling crane, I may conduct the
electric current from the generator to the motor by the rails, insulating these from
each other, or by separate conductors and moveable collectors, and I prefer to employ
one or more electric motors, with suitable gearing for reducing the initial speed, and
increasing the leverage, for moving the travelling crane bodily upon the rails, and a
separate motor or motors for actuating the chain barrel, and moving the carriage
.thereof transversely upon the cross beams of the crane.
Having now particularly described and ascertained the nature of my said Inven-
tion and in what manner the same is to be performed, I declare that what 1
claim is.
First. In a jib crane, the application of an electric motor for operating the chain
'barrel, with suitable gearing interposed between the spindle of said motor and said
chain barrel, substantially as herein described and shewn in the accompanying sheet
of drawings.
Second. The application to the hauling, raising, travelling and swaying gear of jib
and travelling cranes, and sheer legs, of an electric motor or motors for the purpose
of operating said gear, and obtaining the desired motion and power, substantially as
herein described and set forth.
Third. The combination of an electric motor or motors with a crane or sheer legs,
either with or without an electro-magnetic brake, substantially as and for the purposes
herein described and set forth.