Year: 1894

page_text: Date of Application, 21st Sept., 1894
Complete Specification Left, 18th June, 1895-Accepted, 27th July,
1895
A communication from CHARLES ARTHUR MARCHANT, Supervisor, Public Works
Department, Dehree, India."
I, JOHN GILLESPIE, of 121, West George Street, in the County of the City of
Glasgow, North Britain, Engineer, do hereby declare the nature of this invention
to be as follows, that is to say :-
The said invention has for its object the construction of excavators or dredgers
in an improved manner so as whilst greatly increasing the efficiency of the
excavator or dredger to reduce in number and simplify the construction of the
various parts thereby reducing the cost.
In carrying out the invention two grabs or jaws are provided which together
form the bucket. Each grab is, by preference, more or less in the form of a
quadrant of a circle and is constructed with teeth or other excavating device in any
desired manner to suit the material in which it works. The grabs are each centered
in the framing of the excavator at a point as far as possible from what will be the
centre of the bucket consistent with allowing the meeting faces of the grabs to
come together when the bucket is closed, and thus permitting of the greatest force
being exercised at the commencement of the bite when it is most needed for
penetration and vice versú less force will be required for opening the grabs. Two
long levers are formed in connection with each grab these levers turning on the
same centre as the grab and having a weighted rod extending between the outer
ends of each pair on which rods are pulleys round which the chains pass from
where they are fixed in the framing to the jib head and winch barrel. On one of
the grabs a rod or bar is centered, which bar is made long enough to extend across
to the other grab and a hook on its end engages with a rod on that grab when the
bucket has just been emptied and stops the grabs from closing fully when the chains
are beginning to be wound. The hooked bar is connected by a chain with one end
of a lever centered at the upper part of the framing, the outer end of which lever
is acted on by the lower end of a weighted tumbler lever at a certain part of the
operations as hereinafter described. The tumbler lever is made with a book and
cam surface on its upper end. Suspended from the jib head is a bell-like frame
with a ring with which the hook on the tumbler lever engages so as to suspend the
excavator when discharging, the frame and ring being then eccentric to a vertical
line drawn from the jib head through the centre of the bucket.
The parts being in the position described, when it is desired to lower the
excavator the chains connected with the winch barrel are wound sufficiently to
raise the hook on the tumbler lever off the ring of the bell-like frame which will
at once find its own centre of gravity and swing clear of the hook. The excavator
which is partly closed and fixed in that position by the hooked bar extending
between the two grabs as hereinbefore described, may now be lowered by
unwinding the chain on the winch barrel and on touching the silt the grabs will
open out fully thus releasing the hooked bar. The weighted tumbler lever is then
able to act on the outer end of the lever centered at the upper part of the framing
and this lever through the chain attached to its other end and extending down to
the hooked bar lifts that bar clear of the rod with which it was engaged. The
chains connected with the winch may now be wound, and the strains acting through

page_text: the long levers centered on each grab will cause the grabs to close and afterwards
on continuing to wind the chains the excavator will be raised. When raised the
cam surface on the upper end of the tumbler lever (which is kept from descending
too far by a stop) acts on the mouth of the ring of the bell-like frame so as to push
it to one side and allow the hook on the end of the lever to engage with the ring as
bereinbefore stated, then on 'the chains being unwound the grabs will open out and
discharge their contents by the action of the weight of the rods extending
between each pair of levers on the grabs and the hooked bar on the grabs will
fall into position ready to lock the grabs in their open position before being
lowered again which locking action takes place when 'the winch chains are wound
sufficient to lift the hook off the bell.
The action of the excavator with its closing and opening is largely automatic,
and it is worked from the single chain by which it is suspended from the crane or
other apparatus used for lowering and raising it.
Dated this Twentieth day of September 1894
EDMUND HUNT,
Applicant's Agent.
.
A communication from CHARLES ARTHUR MARCHANT, Supervisor, Public Works
Department, Dehree; India.
I, JOHN GILLESPIE, of 121, West George Street, in the County of the City
of Glasgow, North Britain, Engineer, do hereby declare the nature of this inven-
tion and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement, that is to say:-
1
t.
.
The said invention has for its object the construction of excavators or dredgers
in an improved manner, so as whilst greatly increasing the efficiency of the
excavator or dredger to reduce in number, and simplify the construction of the
various parts, thereby reducing the cost.
...
.1
Part of an excavator, as made according to my invention, is shown on three
accompanying sheets of explanatory drawings, Figure, 1, on Sheet, 1, thereof
being a sectional elevation of details, and Figure, 2, an elevation, as at right angles
to Figure, 1, of the bucket (and other parts) in a nearly full open position.
Figure, 3, on Sheet, 2, is an elevation of the bucket (and other parts) in a full
open position, Figures, 4, and 5, are elevations, as at right 'hngles to each other,
with the bucket in a closed position. In these drawings the same reference
letters and numerals are used to mark the same or like parts wherever they are
repeated.
In carrying out the invention two grabs or jaws, A, and B, are provided which
together form the bucket. Each grab, A, B, is, by preference, more or less in the
form of a quadrant of a cylinder, and is constructed with teeth, A 1, and B 1, or
other excavating device in' any desired manner, to suit the material in which it
works. The grabs, A, and, B, are each centered in the framing, C, of the excavator,
on spindles, A 2, and B 2, at a point as far as possible from what will be the centre
of the bucket consistently with allowing "the meeting faces of the 'grabs to come
together, when the bucket is closed, and thus permitting of the greatest force being
exerted at the commencement of the bite when it is most needed for penetration,
whilst, vice versa, less force will be required for opening the grabs. Two long
levers, D, are fixed to each grab, A, B, these levers' turning on the same centres as
the grabs, and having heavy rods or bars, G, H, exténding between and connecting
the outer ends of each pair. On the middle of each bar, G, H, there is jointed a
block fitted with a pulley, J; and round the two pulleys, J, chains, K, pass from

page_text: points of attachment at the upper part of the framing, C, to single chain, K 1,
Figure 3, proceeding to the jib head. On one grab, B, a rod or bar, L, is centered
on a spindle, L1, and this bar is made long enough to extend across to the other
grab, A, and a hook on its end engages with a rod; M, on the grab, A, when the
bucket has just been emptied, and stops the grabs from closing fully when the
chain, K 1, is beginning to be drawn up. The hooked bar, L, is connected by a
chain, L2, with one end of a lever, N, centered at the upper part of the framing, C,
on a pin; N 1, the outer end of which lever is acted on by the lower end of a
weighted tumbler lever, P, centered on a pin, P 1, at a certain part of the opera-
tions hereinafter described. The tumbler lever, P, is made with a book, P 2, and
a cam surface, P 3, on its upper end. Suspended from the jib head is a bell-like
frame, Q, with a ring, Q1, with which the hook, P2, on the tumbler lever, P,
engages so as to suspend the excavator when discharging, the frame and ring being
then eccentric or to one side of a vertical line drawn from the jib head through
the centre of the bucket.
The parts being in the position described, when it is desired to lower the
excavator, the chain, K. 1, connected with the winding machinery is drawn up
sufficiently to raise the hook, P 2, on the tumbler lever, P, off the ring, Q 1, of
the bell-like frame, Q, which will at once by its own weight swing into a central'
position clear of the hook. The hook, P2, of the tumbler lever, P, being clear
of the ring, Q1, the lower end of the lever rests on the outer end of the lever, N,.
which has its other end connected by the chain, L 2, to the hooked bar, L, engaging
the rod, M. The excavator, which is partly closed and fixed in that position by
the hooked bar, L, extending between the two grabs, A, and B, and locking them
together, may now be lowered and on touching the silt or bottom the grabs will be
fully opened out by the action of the weighted levers, D, thus releasing the hooked
bar from its engagement with the rod, M. The weighted tumbler, P, then acts on
the outer end of the lever, N, and this lever through the chain, L 2, attached to its
other end and extending down to the hooked bar, L, lifts that bar upwards away
from the rod, M, with which it was engaged. The chain, K1, connected with the
winding machinery may now be drawn up and the strains acting through the long
levers, D, fixed to the grabs, A, and B, will cause the grabs to close and afterwards
on the drawing up being continued the excavator will be raised. When raised the
cam surface, P3, on the upper end of the tumbler lever, P, (which is kept from
descending too far by a stop, R) acts on the mouth of the ring, Q1, of the bell-
like frame so as to push it to one side and allow the hook, P 2, on the end of the
lever, P, to engage with the ring, Q1, as hereinbefore stated, then on the
chain, K1, being lowered the grabs, A, and B, will be opened out and their
contents discharged, by the action of the weight of the rods or bars, G, and H,
extending between each pair of levers, D, on the grabs, and the booked bar, L,
will fall into position ready to lock the grabs in their nearly full open position
before being lowered again, which locking action takes place when the chain, K 1,.
is drawn up sufficiently to lift the hook off the bell.
The action of the excavator with its closing and opening is largely automatic ;
and it is worked from the chain, K 1, by which it is suspended from the crane or
other apparatus used for lowering and raising it.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The construction, arrangement, and combination of parts constituting my
improved excavator or dredger substantially as herein before described and as
shown in the accompanying drawings.
2. In an excavator or dredger, two grabs or jaws, comprising the excavator
bucket, each centered at a point the farthest from the bucket centre that will allow
the grabs to meet, and made with long levers, to which the hoisting chain is.
connected in a manner to cause the grabs to bite, and which are weighted to cause

page_text: the bucket jaws to open and discharge their contents, when the hoisting chain is
slack substantially as hereinbefore described.
3. In an excavator or dredger, a hooked bar hinged to one bucket grab and
locking with a rod on the other bucket grab, when the grabs are almost full
open, this hooked bar being freed and withdrawn from the locking rod when the
grabs open fully, substantially as hereinbefore described.
4. In combination with the subject matter of Claim, 2, a weighted lever
hinged to the bucket frame and engaging, when the bucket is raised, with a
suspended bell-like frame so as to depend therefrom when the hoisting chain is
slackened, and allow the weighted levers on the bucket to open it and discharge
its contents substantially as hereinbefore described.
Dated this Seventeenth day of June 1895.
EDMUND HUNT,
Applicant's Agent.