Improvements in Dredgers.
Year: 1889

page_text: Date of Application, 17th Aug., 1889
Complete Specification Left, 15th May, 1890-Accepted, 28th June, 1890
PROVISIONAL SPECIFICATION.
Improvements in Dredgers.
I, ROGER WRIGHT of the Elswick Works, Newcastle upon Tyne, Engineer, do
hereby declare the nature of this invention to be as follows:-
This Invention has for its object improvements in dredgers and refers especially
to dredgers such as those described in the Specification of Batho's Patent No. 3421
in the year 1878 where a bucket is carried on a beam rocking about an axis in a
vertical plane.
Heretofore these dredgers have discharged the spoil by shoots into the spoil barges
or other receptacles and these shoots have been so contrived as to be beneath the
bucket when raised but to move out of the way to permit it to descend.
To avoid the necessity for this I mount the rocking beam upon a post which is able
to turn partly round about a vertical axis so that when the beam with the bucket has
been raised it may be turned to one side over the spoil barge and the bucket then
lowered down into the barge before it is made to discharge its contents.
In carrying my invention into practice I prefer to arrange as follows:-
In a barge or lighter suitable pumping apparatus is provided to supply water under
pressure to hydraulic cylinders which actuate the dredging mechanism. A framework
is also erected upon the barge or lighter and it supports a pillar or post in such
manner that the same is free to turn partly round about pivots arranged vertically.
By means of hydraulic gear such as is employed in cranes the post can be turned in
either direction as may be required.
To the post a long beam is jointed and this when turning about the joint moves
in a vertical plane.
At one end of the beam a grab bucket is carried and at the other a counterpoise.
An hydraulic cylinder is mounted upon the post near its upper end; it is carried
by horizontal trunnions about which it can rock. The cylinder contains a piston and
the rod of this piston is jointed to the beam at some distance from the grab bucket
and between it and the joint which connects the beam with the post. By this
cylinder the beam can be thrust down and the grab which it carries forced against
the ground; by it also the beam can be raised to lift the grab with its contents.
Another hydraulic cylinder forms part of the grap bucket and serves to open and
close its jaws.
The cylinders are supplied with water from the pumping apparatus through the
pivots and trunnions.
Valves operated by hand gear control the admission of water to the cylinders and
its passage from them.
In working the apparatus when the lighter is moored in a suitable position the
beam is caused to descend immediately in front of the bows of the vessel and it then
forces the grab, which has its jaws open to enter the ground. Next the jaws are
made to close around the material which they embrace and the beam then rises,
carrying the grab bucket out of the water. Then the post is turned and the beam
is carried round with it so that the grab bucket is brought over a spoil barge secured
alongside of the dredger and finally the grab is lowered down into the barge and
its jaws are opened to deliver the contents.
Dredging buckets of various sorts may be used in dredgers constructed according
to my invention.
Dated this 17th day of Anonst 1889

page_text: COMPLETE SPECIFICATION.
Improvements in Dredgers.
I, ROGER WRIGHT, of the Elswick Works, Newcastle upon Tyne, 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:--
This invention has for its object improvements in dredgers and refers especially
to dredgers such as those described in the Specification of Batho's Patent No. 3421
in the year 1878 where a bucket is carried on a beam rocking about an axis in a
vertical plane.
Heretofore these dredgers have discharged the spoil by shoots into the spoil barges
or other receptacles and these shoots have been so contrived as to be beneath the
bucket when raised but to move out of the way to permit it to descend.
To avoid the necessity for this I mount the rocking beam upon a post which is
able to turn partly round about a vertical axis so that when the beam with the
bucket has been raised it may be turned to one side over the spoil barge and the
bucket then lowered down into the barge before it is made to discharge its contents.
In
In the annexed drawings Figure 1 is an elevation and Figure 2 is a plan of a
dredging vessel and mechanism arranged in accordance with my invention.
Figure 2 a spoil barge is also shown alongside the dredging vessel.
In carrying my invention into practice I prefer to arrange as follows:-
In a barge or lighter a suitable pumping apparatus is provided to supply water
under pressure to hydraulic cylinders which actuate the dredging mechanism. A
framework c is also erected upon the barge or lighter and it supports a pillar or
post & in such manner that the same is free to turn partly round about pivots d¹ d'
arranged vertically. By means of hydraulic gear e such as is employed in cranes
the post can be turned in either direction as may be required.
To the post d a long beam f is jointed at f¹ and this when turning about the
joint moves in a vertical plane.
At one end of the beam fa grab bucket g is carried and at the other a counterpoise h.
An hydraulic cylinder i is mounted upon the post near its upper end; it is carried
by horizontal trunnions about which it can rock. The cylinder contains a piston
and the rod k of this piston is jointed to the beam f at some distance from the grab
bucket g and between it and the joint which connects the beam with the post.
By this cylinder i the beam can be thrust down and the grab g which it carries
forced against the ground; by it also the beam f can be raised to lift the grab with
its contents.
1
Another hydraulic cylinder g' forms part of the grab bucket and serves to open
and close its jaws.
The cylinders are supplied with water from the pumping apparatus b through the
pivots and trunnions.
Valves operated by hand gear control the admission of water to the cylinders and
its passage from them.
In working the apparatus when the lighter a is moored in a suitable position the
beam is caused to descend immediately in front of the bows of the vessel and it
then forces the grab g which has its jaws open to enter the ground. Next the jaws
are made to close around the material which they embrace and the beam f then rises
carrying the grab bucket 9 out of the water. Then the post d is turned and the
beam is carried round with it so that the grab bucket g is brought over a spoil
barge secured alongside of the dredger and finally the grab g is lowered down
into the barge and its jaws are opened to deliver the contents.
to
Dredging buckets of various sorts may be used in dredgers constructed according
my invention.

page_text: 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 :-
A barge or lighter provided with pumping apparatus and hydraulic machinery
actuating a grab bucket carried upon a beam which by the hydraulic machinery can
be turned about vertical and horizontal axes or pivots in such manner that the
bucket after it has been lowered in front of the vessel, closed and lifted again can
be brought over a spoil barge alongside and made to discharge its contents without
the aid of shoots all substantially as described.
ROGER WRIGHT.