Improvements in Dredgers and Excavators.
Year: 1896

page_text: Date of Application, 13th Oct., 1896
Complete Specification Left, 12th Dec., 1896-Accepted, 6th Feb., 1897
PROVISIONAL SPECIFICATION.
Improvements in Dredgers and Excavators.
I WILLIAM JAMES TARRANT Eiffeldale Longfleet Poole Dorset Marine
Engineer and Works Manager do bereby declare the nature of this invention
to be as follows:-
My invention relates more particular to those machines used for excavating
deepening channels canals and the like by means of buckets attached to chains
dragged by power and guided through or across the surface of the material to
be removed in two sets, working simultaneously in opposite directions.
My principle aim has been to obtain a counteraction of the buckets in doing
their work, thereby throwing the least possible strain on the general construction
and moorings, my further object has been to dredge in shallow water, to make
channels for other and larger dredgers, and any boats, and launches, of light
draught, cleaning out canals and the like.
To accomplish this purpose I employ two sets of buckets and disintegrators
working in opposite directions, to further assist, the object I place the buckets
extremely forward working them from side to side and by lowering them thus
cut a channel sufficiently deep & wide to allow the dredger to float through in
one continual action.
Liated this 12th day of October 1896.
Improvements in Dredgers and Excavators.
I WILLIAM JAMES TARRANT "Eiffeldale" Longfleet, Poole in the County of
Dorset Marine and General 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 in this invention is to provide improved and novel means to excavate
channels, trenches, canals, and the like and relates to machinery for dredging or
excavating material above or below water, by means of buckets attached to endles
chains, drawn by power and guided through or across the surface of the material
to be removed and which are not of the ordinary bucket and ladder construction,
but consist essentially of one or more double sets of buckets, disintegrators or
cutters, attached to endless chains, each set having separately its own guides,
frame-work, delivery shoots, driving, and hoisting gear, but working in opposite
directions, thereby creating a counteraction and obtaining a balance of working
strain on the general construction and appliances and producing an approximately
plane and level surface.
To accomplish which, the bucket chains are guided and extended by rollers
fixed in the desired position on the frame-work, the whole of which can be

page_text: withdrawn within the hull when not in use, by means of the hoisting gear fixed to
gantry.
The accompanying drawing illustrates my method of applying my invention,
to dredge or excavate above or below water, whether of harbours, canals, rivers or
swamps and in explanation of same.
Fig. 1. is a transverse section through the machine near one set of buckets.
Fig. 2. is a longitudinal elevation of the same.
F. is the frame-work to which are attached rollers R. R. to guide the chains C
and C¹ on, and between which, are connected the buckets b. b.
At A. and A' are sprocket wheels engaging with the chains and secured to the
shaft, S, which receives its rotary motion by any suitable driving gear from the
motive power, in this instance a worm W. capable of sliding on the vertical
shaft V. and gearing in a worm wheel T. which is also secured to the shaft S.
At H and H is shewn a means of hoisting or lowering the frame-work for the
purpose of regulating the depth of cut feeding the buckets.
D is a shoot to receive and deliver the material discharged from the buckets.
G is a gantry between which the frame-work is guided, also carrying the
hoisting gear H and H mentioned above.
At is another and similar frame-work having corresponding appliances,
namely guide rollers R' chains C3 and C3 buckets bb sprocket wheels A
and A shaft S hoisting gear H¹ and shoot D¹.
The difference being only of position, frame-work F being so placed that the
direction in which its buckets work is opposite to, and above or below, that in
which the others on the frame-work F. act.
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 I
claim is :-
1. A machine for dredging, or excavating material below or above water, having
one or more double sets of buckets and disintegrators, each double set consisting
of two series of buckets and disintegrators affixed to endless chains, extended by,
and guided over suitable rollers, driven in opposite directions, each series of
buckets and disintegrators being independant of the other, and working at different
depths.
2. The combination of the parts F. G. and H for use in conjunction, to lower
and raise the appliance or machine with buckets extended.
3. In a dredger, that when afloat will excavate in shallow water a channel in
any direction, taking two level cuts off the surface the width the buckets are
extended, the first cut being in advance and above the level of the second cut.
Dated this the 11th day of December 1896.
WILLIAM JAMES TARRANT.