IMPROVEMENTS IN FLOATING DREDGERS OR MACHINERY FOR LOOSENING, RAISING, TRANSPORTING, AND DEPOSITING SAND, GRAVEL, AND MUD
Year: 1870

page_text: LETTERS PATENT to Thomas Burt, of Northampton, in the County of
Northampton, Civil Engineer, for the Invention of " IMPROVEMENTS IN
FLOATING DREDGERS OR MACHINERY FOR LOOSENING, RAISING, TRANSPORTING,
AND DEPOSITING SAND, GRAVEL, AND MUD." -A communication from
abroad by James Burt, of Velsen, North Holland.
Sealed the 7th March 1871, and dated the 9th September 1870.
PROVISIONAL SPECIFICATION left by the said Thomas Burt at the
Office of the Commissioners of Patents, with his Petition, on the
9th September 1870..
I, THOMAS BURT, of Northampton, in the County of Northampton,
Civil Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN FLOATING DREDGERS, OR MACHINERY FOR LOOSENING, RAISING,
TRANSPORTING, AND DEPOSITING SAND, GRAVEL, AND MUD," to be as follows:-
The improvements consist in protecting the bottom bearing of the
pump shaft, which by preference is made to work on a pivot, from the
action of the sand or other gritty matter, and giving to the end of the
suction pipe a constant reciprocating motion by means of self-ac.ing.

page_text: machinery for the purpose of loosening the matters to be lifted in
conjunction with water.
The first is effected by causing the end of the pump shaft to work on a
piece of leather, supported by india-rubber of such a thickness as to
prevent the passage of water, the pivot being lubricated with oil con-
tained in a cavity bored in the centre of the shaft for that purpose, and
from whence it can be expelled at intervals by means of a syringe, when
it is desired to renew it.
The second object is attained by arming the end of the suction pipe
with prongs for tearing up the matter to be operated upon. These
prongs are to be kept continually vibrating by machinery herein-after
described, which, combined with_a_transverse movement of the vessel,
-will-bring a great amount of matter within range of the action of the
pump. The mechanism for giving the above-described motion to the
suction pipe, consists of a barrel on which the chain for elevating and
depressing the pipe is wound. This barrel, which receives motion in
opposite directions through gearing from a pulley driven alternately by a
straight and crossed strap, carries at its outer end a pinion giving motion
to a rack. This rack is furnished with tappets or projections that can
be fixed on any desired part, which coming in contact with a bent lever
alternately bring the straight and crossed strap on the fast pulley, and
thus reverse the action of the machine.
In order to prevent the pump or pipe running down whilst the straps
are being shifted by the reversing gear a worm wheel and screw are
introduced to effect the same purpose as is usually attained by a ratchet
wheel and detent.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Thomas Burt in the Great Seal Patent Office on
the 9th March 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS 3
BURT, of Northampton, in the County of Northampton, Civil Engineer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Ninth day of September, in the year

page_text: of our Lord One thousand eight hundred and seventy, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Thomas Burt, Her special licence
that I, the said Thomas Burt, my executors, administrators, and assigns,
or such others as I, the said Thomas Burt, my executors, adminis-
trators, and assigns, should at any time agree with, and no others,
from time to time and at all times thereafter during the term therein
expressed, should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN FLOATING
DREDGERS OR MACHINERY FOR LOOSENING, RAISING, TRANSPORTING, AND DEPOSITING
SAND, GRAVEL, AND MUD," a communication to me from abroad by James
Burt, of Velsen, North Holland, upon the condition (amongst others)
that I, the said Thomas Burt, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and seals,
should particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the same
to be filed in the Great Seal Patent Office within six calendar months
next and immediately after the date of the said Letters Patent.
་
NOW KNOW YE, that I, the said Thomas Burt, do hereby declare
the nature of my said 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 the construction of improved
machinery for loosening, raising, and transporting sand, gravel, and mud
from the bottoms of waters and watercourses; and the improvements
consist, firstly, in protecting the bottom bearing of the pump shaft,
which by preference is made to work on a pivot from the destructive or
injurious action of sand or other sharp or gritty matter; and secondly, in
giving to the end of the suction pipe a constant reciprocating motion by
means of self-acting machinery for the purpose of loosening the matters
to be lifted or raised in conjunction with water.
In carrying out the said Invention I employ a centrifugal pump
mounted on trunnions, and supported by two bearings fixed on a floating
vessel in such a manner as to admit of the suction pipe taking a radial
motion whilst being worked. The pump which may be driven by steam
or other power discharges the dredged materials through one of the
trunions either into barges alongside, or by means of floating pipes

page_text: materiais.
The first improvement is effected by causing the end of the pump
shaft to work on a piece of leather, supported by india-rubber of such
thickness as will prevent the passage of water, the pivot being lubricated
with oil contained in a cavity bored in the centre of the shaft for that
purpose, and from whence it can be expelled or withdrawn at intervals
by means of a syringe when it is desired to renew it.
The second improvement is attained by arming the end of the suction
pipe with prongs for tearing up or otherwise loosening the materials
to be dredged or operated upon. These prongs are kept continually
vibrating in any required_direction-by-means of the machinery herein-
after described, which vibratory motion combined with a transverse move-
ment of the vessel, will bring a great amount of matter within range of
the action of the pump.
The mechanism for giving the herein-before described motion to the
suction pipe consists of a barrel on which the chain for elevating and
depressing the pipe is wound; this barrel which receives motion in
opposite directions through gearing from a pulley driven alternately by
a straight and crossed strap carries at its outer end a pinion giving
motion to a rack; this rack is furnished with tappets or projections that
may be fixed at any desired part of the rack, which coming in contact
with a bent lever alternately bring the straight and crossed straps on to
the fast pulley, and thus reverse the action of the machinery. In order
to prevent the pump or pipe running down whilst the straps are being
shifted by the reversing gear, a worm wheel and worm or screw are
introduced to effect the same purpose as is usually attained by a ratchet
wheel and detent. A counter weight is also added for the purpose of
increasing the speed of the oscillation when working with the pipe nearly
vertical.
In order that the said Invention may be more fully understood, I
shall now proceed to describe the same with reference to the several
Figures on the anexed Sheet of Drawings; where Fig. 1 is a side view
of the general arrangement; and Fig. 2 a plan of the same.
A is a centrifugal pump fixed in framing and supported by trunnions
B, B', on a floating vessel, this pump receives motion by the shaft C,
which shaft is actuated by means of the bevel wheels d, d, and the
pulley e from the steam engine f; G is the suction pipe, and h, h, h, are

page_text: prongs fixed to the end thereof for loosening the materials to be dredged
or operated upon; y, is a rod opening and closing a door y¹ for obtaining
access to the interior of the pump. The distance of the pump from the
surface of the water is not material, provided it be such that no portion
of the pump casing during its oscillation comes out of or above the
water so as to draw air. I is the delivery pipe and is carried through
the trunnion B', where it is connected by means of an india-rubber
pipe B' with floating pipes, or the discharge can be made into a barge
or other vessel alongside; j, j, are studs for attaching the two irons k, k,
one of which is connected with the lifting gear 1, and the other with
the counter weight m.
Fig. 3 is a plan; and Fig. 4 an elevation of the lifting gear; n is the
fast pulley, and n³, n², are loose pulleys; the pulley n which receives the
power from the engine by either a straight or a crossed strap, drives by
means of the two bevelled wheels o, o, and the worm p the barrel q,.
on which barrel the chain for elevating and depressing the suction pipe
is wound. The axle of the barrel q carries on its outer end a pinion r,
giving motion to the rack S, on which rack are fastened where desired
the two tappets t, t; u is an upright shaft carrying the arms 1, 2, and 3.
The arm 2 gives motion to the bar for shifting either of the straps on
to the fast pulley n, which movement is imparted to the said arm 2 by
the tappets t, t, coming in contact with the arm 1; the barrel will then
continue to revolve in one direction until the other tappet comes in
contact with the arm 1; this will cause by means of the arm 2 a change
of the straps on the fast pulley, and thus reverse the action of the
machine. The arm 3 with the lever 4 is for the purpose of reversing
the crab by hand when desired. It will readily be seen that by fixing
the tappets t, t, on the rack S at various distances apart a smaller or
greater amount of oscillation of the pump will be obtained.
Fig. 5 is a section of the lower end of the shaft c, shewing the pivot
bearing and the mode of lubricating it, and also the means employed
for excluding sand and other gritty matters. The space between the
bottom of the bearing cup u and the iron support of the pivot is filled,
so as to be water-tight by a disc of india-rubber which is covered on
the top with leather as shewn. Provision is made for lubrication by
boring a hole in the centre of the shaft for the purpose of containing
the oil, which oil can be introduced or withdrawn or expelled by removing

page_text: the screw V; to expel the oil it is necessary to slightly lift the shaft off
the leather disc and to apply a syringe at the hole V..
Having now described the nature of the said Invention and the
manner of carrying the same into effect, I hereby declare that what I
more particularly claim and desire to secure by the before-mentioned in
part recited Letters Patent are, the following improvements applicable to
pumps and machinery for dredging purposes.
Firstly. The constant reciprocating motion given to the end of the
suction pipe, and the general arrangement of the self-acting machinery
for giving such reciprocating motion to the said suction pipe, substan-
tially as described.
Secondly. Arming the end of the suction pipe with prongs for the
purpose of loosening the materials to be dredged or operated upon.
Thirdly. Protecting the bottom bearing of the pump shaft from the
action of sand or other gritty or injurious matters.
In witness whereof, I, the said Thomas Burt, have hereunto set my
hand and seal, this Third day of March, in the year of our Lord
One thousand cight hundred and seventy-one.
THOMAS BURT. (L.S.)