Improvements in and relating to Dredging Machines.
Year: 1892

page_text: Date of Application, 22nd Jan., 1892-Accepted, 23rd Apr., 1892
COMPLETE SPECIFICATION.
Improvements in and relating to Dredging Machines.
1, ADOLPHE LACOMBE, of 1958 Calle Rivadavia, Buenos Ayres, in the Argen-
tine Republic, 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 relates to the construction of an improved dredging machine to be
called the Lacombe extractor and has for object to provide a machine for
dredging slime and sand from the beds of rivers and the like at any depth, the
improved machine being essentially characterized by the suction of the slime and
sand which is obtained by forcing water into what I term a circular section,
capable of being adjusted as required, formed at the entrance of the suction pipe
for the said slime and sand
My invention consists in certain arrangements of parts which I will describe in
detail with reference to the annexed drawings, in which :-
Figure 1 is a sectional elevation of a dredging machine constructed according to
my invention.
Figure 2 is a plan partly in section.
Figure 3 is a sectional elevation drawn to a larger scale of the end of the
extractor hereinafter described shewing the manner in which the size of the opening
of the suction section can be regulated from the deck.
Figures 4 and 5 are details. .
Figures 6 and 7 are sectional views of parts of the apparatus drawn to a larger
scale.
The improved apparatus is constructed of the following principal parts
:-
A hull having an opening in a longitudinal axial line extending from the stern to
the engine for the vertical working of the inlet pipe V and the outlet pipe X; a
steam boiler A is placed at the forward part of the vessel and is supplied with water
from suction apparatus H. A treble action suction and force pump C communi-
cating by means of the pipe T with an air receiver U is operated by the motor P.
From this receiver passes a pipe V₁ which communicates with the pipe V provided
at its lower part with a water chamber V2 containing the suction apparatus A
which after working forces water and matters through the discharge tube X.
The pumps C draw in water at I through the pipe M provided with a condenser G;
a sight hole N allows of this suction operation being watched.
The sucker A2 which forms the principal part of the apparatus is constructed
of two converging and concentric cones A³, J specially arranged to work by means
of water pressure. It is divided into two parts; the front part A³ is the con-
tinuation of the pipe X and terminates in a trumpet mouth, an external socket J³
is provided which with the part A³ forms a circular chamber V2 into which water
under pressure is forced through the tube V.
The body of the apparatus is formed of two parts A³ and J³ connected together
by bolts, the two converging and concentric cones are adjusted one within the
other leaving between them an opening which I term "circular section." The
water chamber V having no other outlet than this section it results that the water
accumulated in the chamber at a determined pressure passes through this section
at a speed proportionate to the pressure.
This speed produces à vacuum whereby a suction results which increases in
energy as the pressure increases and this suction raises water and matters which
are found in proximity to the mouth of the sucker. When this water and these
matters so sucked in reach the circular section, they are forced into the outlet,

page_text: tube to be discharged into a barge or thrown 200 to 300 meters away by means
of conducting pipes.
A physical law teaches that the columns of water in the pipes V and X, which
are of different diameters, equilibrate themselves; so that the real work of elevation
consists in raising the column of water from the level of the water to the highest
part of the pipe X adding to this work the additional difference of the specific
gravity of the matters to be extracted.
To facilitate the suction of the matters to be extracted I have provided a
disaggregator composed of a shaft B2 passing axially through the body of the
water chamber and the concentric cones and having for support the upper part of
the chamber. This shaft is continued between the two pipes V and X to the
support where it rests. The outer end of the shaft B carries disaggregating
knives and the end is held by a support C bolted on the mouth of the sucker as
shewn in the drawing. These knives which are of steel and of helicoidal form
have a rapid movement of rotation which tends to throw back into the sucker the
matters drawn in and which facilitates their absorption. These knives easily cut
very hard earths and are operated by a steam engine Y as hereinafter described.
The shaft B2 on the other side of the circular section passes through a stuffing
box B³ formed integral with the pipes V and X and the inner end of the shaft is
provided with a bevel wheel D which is operated in the following manner :—
In order to understand the movement of the shaft B combined with that serving
to raise and lower the sucker it should be noticed that the inner ends of the
pipes X and V being curved at right angles, serve as shafts on which the sucker
oscillates. These axial parts of the pipes are supported by a cast iron bracket E²
strongly bolted to the deck of the dredger. The pinion which drives the bevel
wheel is carried by a shaft G2 which traverses the pipe V in its axis of oscil-
lation. This shaft G2 receives its movement from a wheel H² operated by a
pinion mounted on the motor shaft of a machine Y. It will thus be clearly seen
that in lowering or raising the sucker the bevel wheel D² is always in contact with
the pinion whatever the position of the sucker.
To facilitate the disaggregation of the matters whether sand, mud or slime, I
have placed in the semicircular part of the outer end of the sucker, a series of
pipes (Figure 7) which take water from the water chamber at a high pressure.
This water in escaping through the slightly curved outer end of these pipes
effectively aids the suction and the cleansing of the knives.
It is important to properly adjust the relative positions of the cones A.³ and J² con-
stituting the circular section, that is to say, that with the minimum quantity of water
there may be obtained the largest extraction of matter. For this purpose I arrange
the movable cone J2 so as to form a ring and be capable of being moved to and
fro by suitable means operated from the deck of the dredger. I provide the
movable cone with lugs placed diametrically opposite to each other; to these
lugs are bolted two rods K which meet and form one rod K³ at their inner ends.
This rod K is screw-threaded and works in a fixed nut whereby by means of a
crank handle or a hand-wheel the movable cone J can be operated and the size of
the opening of the circular section can be thereby increased or diminished as inay
be required. This combination is very important and I claim the application to
any dredger of a similar apparatus whether the vacuum is obtained by means of
water, air, or steam, for it allows of the size of the opening of the circular section
being easily adjusted to fulfil the conditions of work above mentioned, that is to
say, obtain the greatest extraction possible with the minimum of water, the
adjustment being effected without interfering with the working. This arrange-
ment also allows of varying the circular section according to the different specific
gravity of the matters to be extracted which necessitate a more or less forcible
suction. My apparatus thus constitutes a suction dredger which can be adjusted
according to the specific gravity of the matters to be extracted.
It sometimes happens that the circular section becomes choked by foreign
substances drawn in by the suction and force pump; its freeing in the manner

page_text: bove described which allows of increasing the size of the ope
and does not interrupt the working which is very important.
By this invention it is equally easy if not easier to dred
meters as at 5 meters.
The suction is always produced at a height varying fr
meter 50 centimeters (the distance from the sucker m
section) after which the forcing is effected. According to wh
redge at a greater or less depth, intermediate pipes ar
between the mouth of the sucker and the axial parts of the 1
haft B as well as the rods K, K' for regulating the circula
with constituent pipes equivalent to those of the pipes V and
easy to reach the desired depth.
The towing movement of the dredge is effected in the f
pulley A mounted on the motor shaft of the pump drives by
pulley Q mounted on a shaft E', provided with endless
the winch barrels G, H, K, on which are wound the respe
movement shewn in dotted lines in Figure 2 and guided by p
The raising and lowering of the extractor is also effected
barrel which is operated by the pump in a similar manner
barrels.
At the stern of the dredge a framing L is provided to pr
any shock when it is in the horizontal position shewn in th
say, when not working.
The machinery is so arranged as to economically utilize t
the boiler A to the motors Band Y and any others necessary
D is the single acting air-pump.
E is the feed pump of the boiler.
F is the valve box of this pump.
I is the steam supply cock of the engine on the boiler.
J is the steam pipe.
Kis the discharge pipe to the condenser.
O is the outlet of the air pump.
P is the water supply pipe of the feed pump.
Q is the force pipe from the feed pump to the boiler.
R is the return pipe of the feed pump.
S is the collecting force pipe of the injecting pumps.
B is the steam cock of the small engine on the boiler.
C¹ is the steam pipe of this engine.
D' is the exhaust pipe to the condenser.
Fshews the friction gearing of the endless screws of E.
L' the winches for hauling barges.
M' the lawse holes of the chains from the winches.
N¹ the chain receptacle.
M² the tillers.
No covers of hatchways, and
()² the chain for raising the sucker.
Having now particularly described and ascertained the na
ion and in what manner the same is to be performed, I
claim is
The new dredging machine above described, operating by
njection of this water into the immersed end of the dredgin
to create in this pipe or pipes an ascending and suction c
determined force and speed, the said apparatus comprising,
1. A. vessel of suitable shape and size cut away in the d
from the stern to the machinery in the fore part, whereby
dredging machine is ensured.
Having now particularly described and ascertained the nature of my said inven-
ion and in what manner the same is to be performed, I declare that what I
claim is
The new dredging machine above described, operating by forcing water and the
njection of this water into the immersed end of the dredging pipe or pipes so as
to create in this pipe or pipes an ascending and suction current or currents of
determined force and speed, the said apparatus comprising,
1. A vessel of suitable shape and size cut away in the direction of its length
from the stern to the machinery in the fore part, whereby the stability of the
dredging machine is ensured.

page_text: 2. An arrangement of machinery placed in the fore part of the vessel comprising
one or more steam generators, pumps for drawing in water and forcing it into the
extractor ejectors, condensers &c., motors for operating the pumps, the disaggre-
gator, the winches &c.
3. The extracting apparatus properly so-called constructed of a pipe for forcing
water under pressure, a suction pipe and sucker of special construction into which
these pipes open, the sucker being constructed with a water chamber with an
internal circular section capable of being regulated from the deck of the vessel
and through which circular section passes the water forced in under pressure
which produces, by the upward direction of the injection, the drawing in of
slime and sand and their elevation to the suction pipe, which pipe and that through
which the water is forced out can turn on their inner ends, which constitute axes,
and thus allow of the outer end of the extractor being raised or lowered as
required.
4. The disaggregator having helicoidal knives arranged in the mouth of the
extractor and turning mechanically with a continuous movement independently of
the oscillating movements of the extractor.
5. The use of pipes for conducting a part of the water forced into the entrance
of the sucker for assisting the suction and cleansing the knives of the disaggre-
gator.
6. The combination of parts forming the improved dredging machine herein-
before described and illustrated in the accompanying drawings.
Dated the 22nd day of January 1805
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.