Year: 1885

page_text: I, GEORGE ANDERSON of Arbroath Foundry Arbroath, Forfarshire, Engineer and
Iron Founder do hereby declare the nature of this invention to be as follows:-
My invention which relates to steam cranes consists mainly of an improved
organization of the winding drums, driving gear and other parts and it also
comprises improvements in details of construction hereinafter referred to.
In a steam derrick crane embodying my improvements I fit upon the same axis
behind and between the side posts of the crane the winding drum or barrel upon
which the lifting wire rope or chain is wound, and the jib chain barrel or drum
upon which is wound the wire rope or chain employed to support and raise or
lower the jib of the crane. Both drums or barrels are of large diameter and are
smooth in order to adapt them particularly for wire ropes which I prefer to employ
instead of chains. The winding drum for raising and lowering the load, is keyed
or otherwise secured on its shaft which passes loosely through the eye of the jib
drum and does not drive it. This shaft passes out beyond the side post and is
driven through intermediate gearing from the crank shaft of the engines which are
fitted as usual in the shoe or sole carrying the side posts and jib. The crank shaft
is carried in front of the side posts at a higher level than the winding drums which
are fitted as low as possible in order that the attendant may have a clear view
over them and between the side posts while occupying a convenient position on.
the platform for operating the engines and other gear. The jib lifting drum is
actuated by means of a worm on a shaft driven by bevel gearing from the crank
shaft the worm being geared with a series of small conical rollers fitted on studs
on the periphery of the drum. These rollers are suitably pitched and serve as cogs
or teeth by means of which the drum is driven from the worm, the object of using
them instead of ordinary fixed cogs being to lessen friction. The bevel wheel on
the crank shaft is loose but is brought into action by means of a clutch which is
thrown out of gear while the inclination of the jib is to remain unaltered. In
order to prevent the running down of the jib by the slipping or turning of the
worm shaft which should hold the jib drum stationary when the clutch is out-of
gear, the worm shaft is fitted with a friction pulley or disc with which a cap,
gland, brake strap or similar device is brought into frictional contact to arrest
any tendency to movement of the worm shaft. The friction cap is conveniently

page_text: operated by the action of the hand lever employed to throw the clutch out of gear,
the handle which acts through levers and connecting links on the clutch lever
being fitted on a spindle on whose end is a screw acting on the friction cap
or strap.
For throwing the heaving barrel driving wheel into and out of gear, an inter-
mediate sliding pinion is employed, and to obtain great strength combined with
lightness the driving gears are formed of steel. The slewing gear is of the
ordinary construction and is operated from the crank shaft through worm gearing
and friction clutches the gearing being carried by one of the side cheeks of the
crane.

page_text: I, GEORGE ANDERSON of Arbroath Foundry, Arbroath, Forfarshire, Engineer
and Iron Founder, 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:—
My invention, which relates to steam cranes, consists mainly of an improved
organization of the winding drums, driving gear and other parts, and it also
comprises improvements in details of construction hereinafter referred to.
In the annexed drawings which illustrate the operative parts of a steam derrick
crane embodying my improvements, figure 1 is a back elevation and figure 2 a side
elevation while figures 3 and 4 are elevations, showing in detail the means employed
for throwing into and out of gear, and braking the jib chain barrel.
In the construction of the improved crane I fit upon the same axis behind and
between the side posts A, A, of the crane, the winding drum or barrel B upon
which the lifting wire rope or chain is wound and the jib chain barrel or drum C
upon which is wound the wire rope or chain employed to support and raise or
lower the jib D of the crane. Both drums or barrels B, C, are of large diameter
and are smooth in order to adapt them particularly for wire ropes which I prefer
to employ instead of chains. The winding drum B, for raising and lowering the
load, is keyed or otherwise secured on its shaft b which passes loosely through the
eye of the jib drum C and does not drive it. This shaft b passes out beyond
the side post A and is driven through intermediate gearing from the crank shaft f
of the engines G which are fitted as usual in the shoe or sole H carrying the side
posts and jib, the driving gear consisting in the present case of a spur wheel E
keyed on the shaft b gearing with a pinion E¹ on a shafte having on it a spur
wheel F fitted to gear with a pinion F¹ on the crank shaft f, the pinion F¹ being
adapted to slide on said shaft into and out of gear with the wheel F. The crank
shaft fis carried in front of the side posts A at a higher level than the winding
drums B, C, which are fitted as low as possible in order that the attendant may
have a clear view over them and between the side posts while occupying a
convenient position on the platform I for operating the engines and other gear.
The jib lifting drum C is actuated by means of a worm J on a shaft j driven by
bevel gearing K, K¹ from the crank shaft of the worm being geared into an ordinary
worm wheel or with a series of small conical rollers fitted on studs on the
periphery of the drum C. These rollers are suitably pitched and serve as cogs or
teeth by means of which the drum is driven from the worm, the object of using
this form of gearing, which I do not claim separately as any part of my invention,
being to lessen friction. The bevel wheel K on the crank shaft fis loose but is
brought into action by means of a clutch k which is thrown out of gear while
the degree of inclination of the jib is to remain unaltered. In order to prevent
the running down of the jib by the slipping or turning of the worm shaft; which
should hold the jib drum C stationary when the clutch / is out of gear, the worm
shaft j is fitted with a friction pulley M with which a cap, gland or brake strap m
or similar device is brought into frictional contact to arrest any tendency to move-
ment of the worm shaft. The friction strap m is conveniently operated by the

page_text: action of the hand lever employed to throw the clutch out of gear, the handle N,
which acts as seen particularly in figures 3 and 4 through levers p and p¹ and a
connecting link p² on the clutch lever P being fitted on a spindle Q, on whose end
is a screw q which on being turned by the movement of the handle N acts on the
friction strap m and applies such pressure to the periphery of the pulley M as to
hold the shaftj stationary.
To obtain great strength combined with lightness the driving gears are formed.
of steel. The slewing gear is of the ordinary construction and is operated from
the crank shaft f through worm gearing R, R, and a friction clutch S, the gearing
being carried by a bracket T, on one of the side cheeks of the crane.
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. The combination of parts constituting the operative mechanism of a steam
derrick crane, substantially as hereinbefore described with reference to the
drawings annexeḍ.
2. In a steam derrick crane the arrangement of mechanism described with
reference to figures 3 and 4 of the drawings for simultaneously disengaging the
driving gear of the jib chain drum, and applying a brake to prevent unwinding of
said drum.