A NEW OR IMPROVED HAND DREDGER FOR SINKING WELLS IN FOUNDATIONS OF BRIDGES, AND FOR OTHER SIMILAR USEFUL PURPOSES
Year: 1874

page_text: LETTERS PATENT to William Bull, of Ewell, in the County of Surrey,
Civil Engineer, for the Invention of "A NEW OR IMPROVED HAND
DREDGER FOR SINKING WELLS IN FOUNDATIONS OF BRIDGES, AND FOR
OTHER SIMILAR USEFUL PURPOSES.”
Sealed the 7th August 1874, and dated the 8th May 1874.
PROVISIONAL SPECIFICATION left by the said William Bull at the
Office of the Commissioners of Patents, with his Petition, on the
8th May 1874.
I, WILLIAM BULL, of Ewell, in the County of Surrey, Civil Engineer,
do hereby declare the nature of the said Invention for "A NEW OR
IMPROVED HAND DREDGER FOR SINKING WELLS IN FOUNDATIONS OF BRIDGES, AND
FOR OTHER SIMILAR USEFUL PURPOSES," to be as follows:-
This Invention relates to a novel construction of dredger to be worked
by hand, for the purpose chiefly of working in sand, but which is also
applicable for dredging in other earthy substances such as may exist in
sinking wells for the foundations of bridges, the dredger being capable
of bringing up any loose materials which it can grip, in fact the dredger

page_text: utilizes the well-known principle which causes any tool or instrument to
sink in sand by reason of its own weight, assisted by an agitating or
upward-and-downward motion imparted to it.
The dredger consist of a semicircular or semi-cylindrical metal
receiver made in two parts and working on a joint or simple shaft of
round iron, four arms being attached to the ends or corners of the
quadrants or quarter cylinders, the outer ends of the arms being joined
by cross bars, on which two pulleys or guides are fixed near the ends of
the arms.
Two lengths of chain pass over the top of the receiver (when set ready
for descent) and under the pulleys or guides, the ends of each being
joined by a ring, and the two sections or divisions of the receiver are
now kept from closing by a key consisting of a hook-and-eyė piece, the
eye being secured permanently to one section of the receiver, the hook
fitting temporarily into the other section while descending, but releasing
it when contact is made with the material to be excavated.
In working the machine it is opened on a platform and the key fixed.
It is then lowered on to the material to be raised, and on reaching it the
key releases itself as explained. Then a gentle pulling-and-giving
motion should be applied by means of a thin rope attached to the rings
of the chains. By these means the cutting edges of the machine are
caused to cut into the material to be excavated.
The strain should gradually be increased till there is no further
yielding to the pull which can be applied to the rope.
The machine having now been filled can be raised and landed on the
wooden platform or other elevation, and the operation of resetting it for
lowering again releases the load of subsoil brought up and saves all
trouble of emptying.
It will thus be evident that the feature of originality in this Invention
consists in its capability of being worked by its own gravity, aided by
agitating motion and its penetrating power, whereby the machine
gradually works into the material to be excavated without any sup-
plementary arrangement whatever.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Bull in the Great Seal Patent Office
on the 10th August 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
BULL, of Ewell, in the County of Surrey, Civil Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighth day of May, in the year
of our Lord One thousand eight hundred and seventy-four, in the
thirty-seventh year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said William Bull, Her special
licence, that I, the said William Bull, my executors, administrators,
and assigns, or such others as I, the said William Bull, my execu-
tors, administrators, 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 "A NEW OR
IMPROVED HAND DREDGER FOR SINKING WELLS IN THE FOUNDATION OF BRIDGES,
AND FOR OTHER SIMILAR USEFUL PURPOSES," upon the condition (amongst
others) that I, the said William Bull, 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 William Bull, 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 relates to a novel construction of dredger to be worked.
by hand or otherwise for the purpose chiefly of operating in sand and
similar soft deposits, but which is also applicable for dredging in other
earthy substances such as may exist in sinking wells for the foundations
of bridges and other constructions, the dredger being capable of bringing

page_text: up any loose material which it can grip; in fact the dredger utilizes the
well-known principle which causes any tool or instrument to sink in
sand or soft, material by reason of its own weight, assisted by an
agitating or upward and downward motion imparted to it.
This dredger consists of a semicircular or semi-cylindrical metal
receiver made in two parts and working on a joint or a simple shaft of
round iron or other suitable metal or material, four arms being attached
to the ends or corners of the quadrants or quarter cylinders of which
the body of the dredger is composed, the outer ends of the said arms
being jointed by cross bars, on which two pulleys or guides are fixed
near the ends of the arms.
Two lengths of chain pass over the top of the receiver (when set up
ready for descent) and under the pulleys or guides, the ends of each
length being joined above by a ring, to which should be attached a rope,
and the two sections or divisions of the receiver are now kept from
closing by a key consisting of a hook-and-eye piece, the key being
secured permanently to one section of the receiver, and the hook fitting
temporarily into the other section while descending, but releasing it when
contact is made with the material to be excavated.
In working the machine it is opened and the key fixed. It is then
lowered on the material to be raised, and on reaching the same the key
releases itself as explained. A gentle pulling-and-giving motion should
then be applied by means of the rope attached to the rings of the chain,
and thus the cutting edges of the machine are caused to enter into the
material to be excavated.
The strain should gradually be increased till there is no further
yielding to the pull which can be applied to the rope.
The machine having now been filled can be raised and landed on the
wooden platform, cart, barge, or other recipient, and the operation of
resetting and lowering again releases the load of the subsoil brought up
and saves all trouble of emptying.
In case however of large and powerful machines being used to be
worked by steam or other power it would be preferable to dispense with
the key which is shown in Fig. 4, and instead thereof to use a chain
with two ends, one fastened to each section of the dredger in the place
which the key otherwise would occupy.

page_text: This chain would be loose until the dredger full of sand; mud, or other
material raised had been brought over the platform, barge, cart, or other
recipient, then by putting a strain on it and slacking the other
chains h, h, shown in Figs. 1 and 2, the sections will open and the
contents drop out. In this arrangement the dredger would be lowered.
by the double-ended chain referred to, and when it meets the surface of
the material to be raised the said chain slackens of itself, and the other
chains represented in Figs. 1 and 2 then come into play for filling and
raising the dredger; the machine thus being set for working without the
aid of or necessity for any manual labour.
On the annexed Sheet of Drawings Fig. 1 shows an end elevation of
the dredger complete when the two sections or sectors are closed fully
upon the excavated material ready to be hoisted to the platform or other
recipient.
Fig. 2 represents a similar view of the dredger whilst opened for
discharging the material or in the act of beginning to work its way
into the sand.
Fig. 3 is a plan of the dredger, the chain gear being removed.
Fig. 4 shows the hook-and-eye piece for keeping the receiver open
until it reaches the bottom.
a, a, the two sections, sectors, or quadrants with their cutting
edges at b, b; c, joint or simple shaft; d, d, arms; e, e, cross bars;
ff, loose guide pulleys with guards 9, 9, fixed on them; h, h, two
lengths of chain, with the connecting ring i for the working rope;
k, key by which the sections a, a, of the receiver are locked together
at the top and held open at the bottom previously to its touching the
material to be dredged or excavated, when it automatically opens as
described. This key occupies the central portion of the upper longi-
tudinal edges m, m, of the sections a, a; n, n, are rivets on the
receiver; o, material excavated.
From the preceding description of the nature of this Invention and
of the manner in which it is or may be carried into operation it will be
evident that the feature of originality claimed in this Invention consists
in its admitting of the dredger, as herein-before specified, being worked
by its own gravity, aided by an agitating motion and its own penetrating
power, whereby the machine gradually works into the material to be

page_text: excavated without any supplementary or outside arrangement whatever
being required.
In witness whereof, I, the said William Bull, have hereunto set
my hand and seal, this Ninth day of July, A.D. 1874.