Improvements in Apparatus for Pumping and Dredging.
Year: 1895

page_text: Date of Application, 11th Dec., 1895
Complete Specification Left, 9th Oct., 1896-Accepted, 11th Dec., 1896
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Pumping and Dredging.
We, JOHN GWYNNE, of Hammersmith Iron Works, Hammersmith, in the
County of Middlesex, Engineer, and EDWARD WASHBOURN SARGEANT, of
Hammersmith Iron Works, aforesaid, Engineer, do hereby declare the nature of
this invention to be as follows:—
This invention has reference to improvements in apparatus for pumping and
dredging, the pump being of centrifugal type. For suction dredging apparatus
has been employed comprising a centrifugal pump, a length or lengths of pipe
connected to the inlet of the pump and capable of being lowered to the bed of the
river or other place to be dredged, and a mouth piece connected to the lower end
of such pipe. In a pump such as referred to it is essential to maintain an adequate
velocity of the liquid and matter passing through to which end pumps have been
so constructed that the spaces enclosed between the pump casing and any two
propeller vanes or blades have constituted passages whose cross sectional area,
that is the area in a plane at right angles to the flow through the passage, has
been the same, or approximately so, in extent though not in shape from the end
nearer the pump axis to the discharge end, near the encircling outlet or delivery
passage of the pump and this has been done by making that part of the pump
casing occupied by the appropriately formed rotary propeller of gradually
decreasing width towards the outer circumference thereof communicating with.
the encircling outlet passage. But this construction of pump is liable to be
clogged by portions of dredged matter accumulating in the narrower parts of the
passages formed as aforesaid by and between the casing and propeller vanes or
blades.
Now in order to obviate this disadvantage without impairing the efficiency of
the pump, its casing is according to this invention so constructed and arranged
that the side walls of the propeller containing chamber are where the vanes or
blades travel between them parallel and the vanes or blades of the propeller are so
formed that where a passage occurs between the back of one blade and the
adjacent face of another the cross-sectional area (not the shape) of such passage
shall as heretofore be the same or approximately so at different points in the
length of the passage but without the gradual diminution in width towards the
discharge end of such passage. Instead of the passage or space between each two
blades being at both sides in communication with the suction pipe, they are
arranged so that the inlets to alternate passages or spaces are located at opposite
sides of the propeller in order to balance the propeller or in other words to obviate
liability to its being forced to one side or other of its enclosing chamber.
In one construction each vane or blade comprises a front portion, a backwardly
curved rear portion and a connecting web and each passage through the propeller
extends between the front portion of one such vane or blade and the rearward
portion of the vane or blade next to it and is a curved passage starting within the
body part of the propeller to one side of its centre or boss and having one of its
sides formed by a portion of the propeller and as it proceeds outward gradually
approaching the wall at the corresponding side of the casing; at the outer side of
each passage there is, at its inner end, a lateral projection from the propeller which
forms a portion of an annulus bevelled at its outer edge and extending from the.
front face of one vane or blade to a little beyond the inner portion of the front

page_text: face of the next vane or blade in rear.
In the casing there are at the respective
sides annular faces opposite which the just mentioned lateral projections of the
propeller travel.
Pumps with alternately arranged passages through the propellers as described
may be constructed in various forms.
A mouth piece according to this invention comprises a chamber or casing which,
or part of which, is without a bottom or floor and which is provided with louvre
like plates or parts with means for readily adjusting them in suchwise that they
may be caused to assume angles such that water entering the chamber or casing
through openings in the upper part thereof will be directed downwardly in such a
way as to have a more or less scooping action upon the surface to be dredged, but
that, in the event of clogging, the positions of the louvre like plates or parts can
be readily changed so that water entering from the top, instead of being projected
against the surface to be dredged as above mentioned, will be allowed to flow
directly to the auction pipe. The details of construction will depend to some
extent upon particular applications.
In one construction, the chamber or casing is pivoted or hinged to the suction
pipe so as to enable it to take a proper bearing on the surface to be dredged and
is formed at the top with openings, on the suction side of each of which is arranged
a louvre-like plate secured to a pivot mounted in the sides of the chamber and
having an adjusting lever extending to the exterior of the chamber or casing.
The adjusting levers are linked together and connected to the piston rod of a
hydraulic cylinder, which is mounted on the chamber or casing and provided with
means whereby water under pressure can be conducted to either side of its piston
at will and the position of the louvre-like plates thus changed according to
requirement. Other means, such as a lever arrangement, may be employed to
actuate the plates, if desired. The plates or louvres are preferably corrugated or
pleated so that the water is directed against the surface to be dredged in jet-like
forms.
In another construction, on the suction side of the openings through which the
water passes to the chamber or casing, inclined plates are fixed, movable plates
being arranged on the other side of the openings, in such a manner that by
adjusting the latter the passages between the two sets of plates can be regulated and
the water thus directed with more or less force against the surface to be dredged.
In some cases instead of employing adjustable louvre-like plates or parts, fixed
plates may be arranged across the chamber or casing so as at all times to direct
the water on to the surface to he dredged in a direction so inclined as to have a
scoop-like action, or, in other words, to pass on towards the pump carrying with it
matter dislodged from the surface being dredged.
Dated this 11th day of December 1895.
COMPLETE SPECIFICATION.
Improvements in Apparatus for Pumping and Dredging.
We, JOHN GWYNNE, of Hammersmith Iron Works, Hammersmith, in the
County of Middlesex, Engineer, and EDWARD WASHBOURN SARGEANT, of
Hammersmith Iron Works, aforesaid, 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 reference to improvements in apparatus for pumping and

page_text: dredging, the pump being of centrifugal type. For suction dredging, apparatus
has been employed comprising a centrifugal pump, a length or lengths of pipe
connected to the inlet of the pump and capable of being lowered to the bed' of the
river or other place to be dredged, and a mouth piece connected to the lower end
of such pipe. In a pump such as referred to, it is essential to maintain an adequate
velocity of the liquid and matter passing through, to which end pumps have been
so constructed that the spaces enclosed between the pump casing and any two
propeller vanes or blades have constituted passages whose cross sectional area,
that is the area in a plane at right angles to the flow through the passage, has
been the same, or approximately so, in extent, though not in shape, from the end
nearer the pump axis to the discharge end near the encircling outlet or delivery
passage of the pump, and this has been done by making that part of the pump
casing occupied by the appropriately formed rotary propeller of gradually
decreasing width towards the outer circumference thereof where it communicates
with the encircling outlet passage. But this construction of pump is liable to be
clogged by portions of dredged matter accumulating in the narrower parts of the
passages formed as aforesaid by and between the casing and propeller vanes or
blades.
Now in order to obviate this disadvantage without impairing the efficiency of
the pump, its casing is according to this invention so constructed and arranged
that the side walls of the propeller containing chamber are, where the vanes or
blades travel between them, parallel or approximately so, and the vaues or blades
of the propeller are so formed that where a passage occurs between the back of
one blade and the adjacent face of another the cross-sectional area (not the shape)
of such passage shall as heretofore be the same or approximately so at different
points in the length of the passage but without the gradual diminution in width
towards the discharge end of such passage. Instead of the passage or space
between each two blades being at both sides in communication with the suction
pipe, they are arranged so that the inlets to alternate passages or spaces are located
at opposite sides of the propeller in order to balance the propeller or in other
words to obviate liability to its being forced to one side or other of its enclosing
chamber.
Pumps with such alternately arranged passages through the propellers may be
constructed in various forms.
In the accompanying drawings, Figs. 1 and 2 illustrate a construction of pump
according to this invention, Fig. 1 being a section in a plane passing through the
axis of the pump, the casing of which is indicated in dotted lines, the propeller in
full lines; and Fig. 2 is a side elevation of the propeller removed from the
casing.
The side walls 1, 1 of the propeller containing chainber are parallel where the
propeller vanes or blades which are correspondingly formed as regards width,
travel between them.
Each vane or blade comprises a front portion 2 a backwardly curved rear
portion 2b and a connecting web 2° and each passage 3 through the propeller
leading from the inlet to the outlet passage of the pump extends between the front
portion of one such vane or blade and the rearward portion of the vane or blade next
to it and is a curved passage starting within the body part of the propeller to one
side of its centre or boss 4 and having one of its sides formed by a portion 5 of
the propeller and as it proceeds outward gradually approaching the wall at the
corresponding side of the casing; at the outer side of each passage there is, at its
inner end, a lateral projection 6 from the propeller which forms a portion of an
annulus bevelled at its outer edge and extending from the front face of one vade
or blade to a little beyond the inner portion of the front face of the next vane or
blade in rear.
In the example there are four passages 3, the inlets to alternate
passages being at opposite sides of the propeller, but it is obvious the number of
passages may vary. In the casing there are at the respective sides annular

page_text: faces 7 opposite which the just mentioned lateral projections of the propeller
travel.
The faces 7 are in the example illustrated formed on a removable lining 8 that
is fitted within the propeller containing chamber and can be renewed from time to
time as it becomes worn by the abrasion of the dredged material passing through
the pump:
Fig. 3 is a corresponding view to Fig. 1 and Fig. 4 shews a side elevation partly
in section of a modified construction wherein the propeller has six alternately
arranged passages and in which the propeller is partly shrouded for the purpose
of obviating abrasion of the lining 8 by dredged material. 99 are the side
shroudings of the vanes; they are formed with annular lateral projections 6 that
travel opposite annular faces 7 in the casing. The webs between the parts 2 and 2b
of the vanes or blades are dispensed with, as the shroudings serve to connect those
parts together.
A mouth piece according to this invention comprises a chamber or casing which,
or part of which, is without a bottom or floor and which is provided with louvre
like plates or parts with means for readily adjusting them in such wise that they
may be caused to assume angles such that water entering the chamber or casing
through openings in the upper part thereof will be directed downwardly in such a
way as to have a more or less scooping action upon the surface to be dredged, but
that, in the event of clogging, the positions of the louvre like plates or parts can
be readily changed so that water entering from the top, instead of being projected
against the surface to be dredged as above mentioned, will be allowed to flow
directly to the suction pipe. The details of construction will depend to some
extent upon particular applications.
In some cases instead of employing adjustable louvre-like plates or parts, fixed
plates may be arranged across the chamber or casing so as at all times to direct
the water on to the surface to be dredged in a direction so inclined as to have a
scoop-like action, or, in other words, to pass on towards the pump carrying with it
matter dislodged from the surface being dredged.
Figs. 5 to 10 inclusive of the accompanying drawings illustrate several
constructions of mouth-pieces, like reference numbers being used to indicate similar
parts.
Fig. 5 is a longitudinal section of a construction in which the chamber or
casing 10 is pivoted or hinged to the suction pipe 11 so as to be able to take a
proper bearing on the surface to be dredged and is formed at the top with
openings 12, on the suction side of each of which is arranged a louvre-like
plate 13 secured to a pivot 14 mounted in the sides of the chamber and having an
adjusting lever 15 extending to the exterior of the chamber or casing. The
adjusting levers are linked together by a link 16 and connected to the piston rod
of a bydraulic cylinder 17, which is mounted on the chamber or casing and
provided with means which may be such as hereinafter described whereby water
under pressure can be conducted to either side of its piston at will and the position
of the louvre-like plates thus changed according to requirement. Other means,
such as a lever arrangement, may be employed to actuate the plates, if desired.
The chamber or casing 10 is without a bottom or floor beneath the plates 13 which
are preferably corrugated or pleated as shown so that the water is directed against
the surface to be dredged in jet-like forms. The movement of the mouthpiece is
limited by a chain connecting its outer end to an arm 18 attached to the suction
pipe.
Figs. 6 and 7 illustrate in longitudinal vertical section and plan respectively
another construction of mouthpiece in which 12, 12, are the inlet openings for
admitting water to the chamber or casing 10; and 20 are fixed plates arranged
across it so as to direct the water on to the surface to be dredged in a direction so
inclined as to give a scoop like action thence to the pump. 13, 13ª are louvre-like
plates mounted on pivots 14 and 14ª. The pivot 14 has an adjusting lever 15

page_text: connected to the piston of the hydraulic cylinder 17. The free end of the
plate 13* rests on the free end of the plate 13, so that upon the piston being forced
out, the plates 13, 13 will be turned upwardly about their pivots as indicated by
dotted lines and the water entering the chamber, instead of being projected
against the surface to be dredged to the extent as indicated by the arrow (Fig. 6),
will be allowed to flow more directly to the pump. 19, 19 are flexible pipes
connecting the cylinder at opposite sides of the piston with pipes 21, and 21*
attached to the suction pipe 11 and connected to a source of water under pressure.
10 is a balance weight for ensuring the mouth piece taking a proper bearing on
the surface to be dredged.
Fig. 8 illustrates in longitudinal vertical section a mouth piece in which there
are fixed plates 20 and there is an opening 21 controlled by a louvre like plate 13
operated in a similar manner to the plate 13 of the arrangement shown in Figs. 6
and 7. By means of this plate all the water entering the chamber or casing 10
can be projected against the surface to be dredged, or, if the opening 21 be
uncovered as shown only part of the water will be downwardly projected, the
remainder passing through the passage 22 and hole 23 directly to the suction
pipe.
Figs. 9 and 10 are respectively a longitudinal vertical section and a plan with
parts removed of a mouth piece somewhat similar to that illustrated in Fig. 8 but
in which the water entering through the openings 12 is at all times directed on to
the surface to be dredged, the passage 22 is dispensed with and an opening 21 is
provided in the inclined plate 20 forming part of the top of the casing, the
passage of water from the exterior to the interior of the chamber or casing 10
through said opening being controlled by a hydraulically operated louvre like
plates 13.
Fig. 11 is a side view of a portion of a dredger barge fitted with apparatus
such as described for pumping and dredging according to this invention. The
mouth piece is of the kind illustrated in Figs. 6 and 7 and the hydraulic cylinder 17
is connected to a steam pump 24 by the pipes 19, 19* 21, 21" and flexible connecting
pipes 25, 25*.
Fig. 12 illustrates the steam pump 24 and its connections to a larger scale.
26 is a pipe conducting water to the pipes 25 and 25* with the latter of which it
freely communicates at all times whilst its communication with the former is
controlled by a three way cock 27 adapted to place the pipe 25 in connection with
the pipe 26 or with an exhaust pipe 28. If the pipe 25 be in communication with
the pipe 26 water under pressure will be on both sides of the piston of the
hydraulic cylinder 17 and as the effective area of the outer side of the piston is
less than that of the inner, the piston will be moved outward and the plates 13 will
be moved so as to allow water to pass directly to the suction pipe 11. On the
cock being turned so as to place the pipe 25 in communication with the exhaust
pipe, 28, the piston will be moved back and the plates 13 be operated so as to
prevent the flow of water direct to the suction pipe.
To provide for the opening and closing of the cock 27 at regular intervals its
lever 27 is connected by a rod 29 to a crank 30 continuously driven from the
pump 23 through a connecting rod 31, pawl lever 32, pawl 33 and a ratchet wheel 34
fixed on the crank shaft 35.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. In pumping apparatus of the kind herein referred to constructing the pro-
peller with passages substantially such as described each between the back of one
vane or blade and the adjacent face of another, such passages being not only of the
same or approximately the same cross-sectional area at different points in their
length but also without gradual diminution in width towards their discharge ends
as set forth,

page_text: 2. A centrifugal pump, propeller wherein the passages between the vanes or
blades are arranged with their inlets alternately at opposite sides of the propeller,
substantially as described.
3. My improved centrifugal pumping apparatus substantially as described with
reference to and illustrated in Figs. 1 and 2, and in Figs. 3 and 4 respectively of
the accompanying drawings.
4. In apparatus for pumping and dredging as herein referred to constructing the
mouth piece of the suction pipe in the form of a chamber or casing which, or part
of which, is without a bottom or floor, and which has inlet openings in its upper
part and is provided with louvre-like plates or parts and with means for readily
adjusting them in such wise that they may be caused to assume angles such that
water entering the chamber or casing through the inlet openings will be directed
downwardly so as to have what we term a more or less scooping action upon the
surface to be dredged, substantially as described.
5. In apparatus for pumping and dredging as herein referred to the combination
and arrangement of parts described with reference to and illustrated in Fig. 5 of
the drawings for the purpose mentioned.
6. In apparatus for pumping and dredging as herein referred to the construction
of mouthpieces comprising casings with open bottoms and with inlet openings fixed
plates for directing water on to the surface to be dredged in a direction so inclined
as to have what we term a scoop like action as set forth.
7. In apparatus for pumping and dredging as herein referred to the construction
of mouthpieces comprising casings with open bottoms and with inlet openings and
plates for directing water on to the surface to be dredged in a direction so inclined
as to have what we term a scoop-like action substantially as described with
reference respectively to Figs. 6 and 7, Fig. 8 and Figs. 9 and 10 of the
accompanying illustrative drawings.
Dated this 9th day of October 1830.
For the Applicant,
W. Lloyd Wise,
JOHN GWYNNE.
46 Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.