IMPROVE. MENTS IN CRANES OR HOISTS FOR WORKING EXCAVATORS OR OTHER APPLIANCES USED IN RAising or LoWERING AND DEPOSITING Materials.
Year: 1881

page_text: LETTERS PATENT to William Duff Bruce, of Calcutta, India, at present of
Victoria Street, in the City of Westminster, for an Invention of "IMPROVE.
MENTS IN CRANES OR HOISTS FOR WORKING EXCAVATORS OR
OTHER
APPLIANCES USED IN RAising or LoWERING AND DEPOSITING Materials.
PROVISIONAL SPECIFICATION left by the said William Duff Bruce at the
Office of the Commissioners of Patents on the 2nd July 1881.
WILLIAM DUFF BRUCE, of Calcutta, India, at present of Victoria Street, in the
City of Westminster. "IMPROVEMENTS IN CRANES OR HOISTS FOR WORKING
EXCAVATORS OR OTHER APPLIANCES USED IN RAISING OR LOWERING AND
DEPOSITING MATERIALS."
My Invention relates to improvements in cranes or hoists for working excavators,
skips, or other appliances in which the blades are opened and closed for the purpose
of depositing or excavating materials.
•
It consists in applying to the winch of a crane or hoist a barrel composed of two
drums, one of which is fixed and the other loose on the spindle or shaft of the
barrel. The loose drum is provided with a friction brake, and the fixed drum
with keys for locking the loose drum when it is necessary to raise the excavator
with the blades open. These keys are thrown in and out of gear with the loose
drum by a sliding disc on the shaft worked by a forked lever.
The two drums are formed with snugs on their inner ends for limiting the
rotation of the loose drum in either direction, independent of the fixed drum, to the
extent required for opening or closing the blades of the excavator or other
appliance.
The opening and lowering rope or chain of the excavator or other appliance is
coiled onto the loose drum, and the lifting and closing rope or chain on the fixed
drum.
When the excavator or other appliance has been lowered open, the fixed drum is
moved by the gearing sufficient to close the excavator. When the snug of the
fixed drum comes against a snug on the loose drum, and the drums revolve

page_text: together, the excavator being then lifted to any required height by the lifting rope.
When the excavator is to be opened the loose drum is held fast by the brake, and
the motion of the fixed drum reversed.
The opening rope is thus held stationary while the lifting rope is allowed to
uncoil sufficiently to open the blades of the excavator. When the fixed drum has
moved this distance, its snug comes against another snug on the loose drum,
thereby taking the latter with it. The excavator can then be lowered by merely
casing the brake.
When necessary to lift the excavator open, the locking keys are thrown into gear
with the loose drum, and the two drums thereby revolving together the excavator
can be lifted.
Suitable clutches are provided for preventing the excavator from rising whilst
its blades are being forced into the soil.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Duff Bruce in the Great Seal Patent Office on the
2nd January 1882.
WILLIAM DUFF BRUCE, of Calcutta, India, at present of Victoria Street, in the
City of Westminster. "IMPROVEMENTS IN CRANES OR HOISTS FOR WORKING
EXCAVATORS OR OTHER APPLIANCES USED IN RAISING OR LOWERING AND
DEPOSITING MATERIALS."
My Invention relates to improvements in cranes or hoists for working excavators,
skips, or other appliances in which the blades are opened and closed for the purpose
of depositing or excavating materials.
It consists in applying to the winch of a crane or hoist a barrel composed of two
drums, one of which is fixed and the other loose on the spindle or shaft of the
barrel. The loose drum is provided with a friction brake, and the fixed drum
with keys for locking the loose drum when it is necessary to raise the excavator
with the blades open. These keys are thrown in and out of gear with the loose
drum by a sliding disc on the shaft worked by a forked lever. The two drums
are formed with snugs on their inner ends for limiting the rotation of the loose
drum in either direction, independent of the fixed drum, to the extent required for
opening or closing the blades of the excavator or other appliance.
The opening and lowering rope or chain of the excavator or other appliance is
coiled onto the loose drum, and the lifting and closing rope or chain on the fixed
drum.
When the excavator or other appliance has been lowered open the fixed drum is
moved by the gearing sufficient to close the excavator when the snug of the fixed
drun comes against a snug on the loose drum, and the drums revolve together, the
excavator being then lifted to any required height by the lifting rope. When the
excavator is to be opened the loose drum is held fast by the brake, and the motion
of the fixed drum reversed. The opening rope is thus held stationary while the
lifting rope is allowed to uncoil sufficiently to open the blades of the excavator.
When the fixed drum has moved this distance, its snug comes against another snug
on the loose drum, thereby taking the latter with it. The excavator can then be
lowered by merely easing the brake. When necessary to lift the excavator open
the locking keys are thrown into gear with the loose drum, and the two drums
thereby revolving together the excavator can be lifted. Suitable clutches are
provided for preventing the excavator from rising whilst its blades are being forced
into the soil.
And in order that my said Invention may be well understood, I shall now
proceed more particularly to describe the same, reference being had to the accom-
panying Sheets of Drawings, like letters of reference indicating corresponding parts
in all the Figures.
Figure 1, Sheet 1, is a side elevation; Figure 2 a plan, and Figures 3, 4, and 5,
detailed views of parts of my improved crane or hoist.
In carrying out my Invention I apply to the winch of a crane or hoist a barrel
composed of two drums A and B (seen in section, Figure 3), one of which A is
fixed, and the other B loose on the spindle or shaft C of the barrel. The loose
drum B is provided with a friction brake D, and the fixed drum A with keys E for
locking the loose drum B when it is necessary to raise the excavator F with its
blades open. These keys E pass through the fixed drum A, and are attached at
their outer ends to a disc G (Figs. 2 and 3), which has a groove H on its periphery
and revolves with the fixed drum A, but is free to move along the shaft C. A
lever I with a forked end (Figs. 1 and 2) fitting into the groove H is employed to
throw the locking keys E in and out of gear as required. The two drums A and B
forming the barrel of the winch are formed with snugs cast on the inner end of
each, and these snugs fix the distance which the loose drum B can move in either

page_text: direction independent of the fixed drum A. They are adjusted so that this
movement is exactly the extent required for opening or closing the blades of the
excavator F. Beyond this limit the drums A and B must revolve in either
direction, so that the opening and lowering rope or chain K is coiled onto the loose
drum B when the excavator F is being lifted at exactly the same rate as the lifting
and closing rope or chain L is coiled onto the fixed drum'A. Similarly when the
excavator F is being lowered, the closing rope or chain L is uncoiled at the same
rate as the lowering chain K, and there is no slack rope in either case. The
operations connected with the working of the excavator F are thus performed.
When it has been lowered open the fixed drum A is moved by the gearing sufficient
to close the excavator F. This being done the snug M on the fixed drum A
(Fig. 5) comes against the snug N on the loose drum B, and the drums A and B
revolve together, so long as the fixed drum A is moved in the same direction.
The excavator F can then be lifted to any required height by the chain or rope L,
while the rope or chain K will be coiled up on the loose drum B at the same rate.
When the excavator F is to be opened the loose drum B is held fast by the
brake D, and the motion of the fixed drum A reversed. The rope or chain K
attached to collar (or its equivalent) O is thus held stationary while the rope or
chain L attached to collar (or equivalent), P is allowed to uncoil sufficiently to open
the blades of the excavator F. When the fixed drum A has travelled this distance
its snug M comes against another snug Q on the loose drum B, and cannot move
further without taking the latter with it. The excavator F can then be lowered
by merely easing the brake D, and the lifting chain L will be uncoiled at the same
rate as the lowering chain K. Should it be necessary to lift the excavator F open,
the locking keys E, E, are inserted by the lever I, and the two drums A and B
will then work together, and the excavator F can be lifted open by the rope or
chain K.
According to another arrangement of crane or hoist, where steam is used as the
operating power, I may use (as shewn in the transverse section and end view
respectively, Figures and 7, Sheet 2) a coupling W actuated by a clutch and
lever in the usual way for locking the loose drum B when required in lieu of the
locking keys E, E, (Figs. 1 and 2), in which case I provide the fixed drum A with
a brake D', so that the drum A and excavator F may be held stationary whilst
swinging or radiating the crane or hoist.
To prevent the excavator F from rising while its blades are being forced into
the soil, the tube R is held by the clutches S and T (Fig. 2), which are worked by
pulling the lever U (Figs. 1 and 2) downwards, when a strain is brought on the
rope or chain V, causing the clutches S, T, to close and grip the tube R securely.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried into
effect, I would observe in conclusion that what I consider novel and original, and
therefore claim as my Invention is,―
The construction and arrangement of winch barrel composed of two drums, one
of which is fixed to the shaft, and the other allowed to revolve loose thereon for
the distance required to open and close the excavator or other appliance, substan-
tially as and for the purposes hereinbefore described and illustrated by the
accompanying Drawing.
In witness whereof, I, the said William Duff Bruce, have hereunto set my
hand and seal, this Second day of January, in the year of our Lord One
thousand eight hundred and eighty two
WM. DUFF BRUCE. (L.S.)