IMPROVEMENTS IN TUNNELLING MACHINERY
Year: 1876

page_text: LETTERS PATENT to John Dickinson Brunton and George Brunton, both of
Leighton Crescent, Kentish Town, in the County of Middlesex, Civil Engineers,
for the Invention of "IMPROVEMENTS IN TUNNELLING MACHINERY."
PROVISIONAL SPECIFICATION left by the said John Dickinson Brunton
and George Brunton at the Office of the Commissioners of Patents on the 3rd
April 1876.
JOHN DICKINSON BRUNTON and GEORGE BRUNTON, both of Leighton Crescent,
Kentish Town, in the County of Middlesex, Civil Engineers. "IMPROVEMENTS IN
TUNNELLING MACHINERY."
Our Invention relates to improved combinations and arrangements of apparatus
to be employed in tunnelling, whereby the operations of boring the tunnel, guiding
and securing the machinery, and removing the materials excavated are performed
with facility in a rapid and efficient manner.
In carrying out our Invention we employ a revolving cutting head, by preference
of a hemispherical shape built up of plates, so bent and spirally arranged and
inclined that their protruding edges shall form cutters whereby the chalk or other
material shall during the revolution of the head be pared away, spaces being left
between the protruding and intruding edges of these plates for the escape of the
inaterials excavated into the interior of the head. The anterior portions of these
plates are firmly held together by each being attached to a circular "centre piece"
which likewise forms the fulcrum of a "steering pipe" herein-after referred to,
whilst the posterior portions are tightly fixed to a large ring which forms a journal
for the head. The interior of the "head" is divided radially into boxes or buckets,
into which as the "head" revolves the material removed by the cutters falls.
The steering pipe herein-before mentioned, which is intended to facilitate the
guiding or directing of the head in its motion, passes through the centre of the head
and protrudes slightly from its exterior; it rests on the centre piece herein-before
mentioned in a spherical bearing, by which it is enabled to move in any required
direction. A passage is made for the pipe in advance of the "head" by means of a
screw augur on its interior, driven from the engine herein-after mentioned by any
convenient means, and the borings so formed in its progress fall through openings in
[Price Gd.]

page_text: the pipe. This pipe is guided by an arrangement of screws and adjusting nuts, or
by other suitable means.
We also employ in combination with the revolving head two or more expanding
chambers capable of being immoveably jammed in the tunnel at pleasure, and of
being separated or drawn towards each other, as required, in order to perform
the work.
The expanding chambers, which are constructed by preference of boiler plate, are
split or divided longitudinally in order to allow of their expansion, which we
accomplish by means of small hydraulic presses. This expansion fixes or jams the
chambers tightly within the tunnel, and enables them to resist the pressure
necessary for the excavation and for the moving of each other to and fro within it.
The chambers are arranged longitudinally the one behind the other.
To the anterior portion of the leading chamber there is firmly fixed a ring, into
which the "head" ring before mentioned is introduced, and by which the required
position of the head is maintained and the same is kept up to its work.
In the anterior portion of the following chamber there are fixed hydraulic jacks,
the rams of which are attached to the posterior portions of the leading chamber, and
the jacks are so constructed that by altering the direction of the water they may be
nade to draw the chambers closer to each other or to repulse them, the chamber
which draws or pushes being expanded, and the chamber which is drawn or pushed
being allowed to contract.
To the lower outer surface of the chambers there are attached keel pieces, the
object of which is to plough up a groove in the interior surface of the tunnel for
their own passage, and in which they may be imbedded, whereby they are enabled
to resist the tendency of the hydraulic jacks to turn the chambers instead of the
head.
The boxes or buckets into which the interior of the "head" is divided rise on the
delivery side as the head rotates, and the material which has fallen into them is
prevented from being discharged prematurely by means of an overfall plate which
extends upwards to a sufficient distance and is then turned down and forms a
shoot for the material, and which directs it on to an endless band supported by
brackets and worked by a power engine at a sufficient velocity to convey away all
the material as fast as it is excavated to wagons provided for its discharge.
The method above described of collecting and disposing of the material excavated
may be employed in connection with other tunnelling machines.
In some cases we should however employ in substitution for the arrangement of
boxes or buckets herein-before referred to a series of scoops which are arranged
obliquely on the circumference of a conical drum and work in contact with a semi-
annular plate forming a portion of the frustum of a cone, in such a manner that as
the drum revolves the scoops collect and carry up the material excavated, and
discharge it over the top edge of the semi-annular plate down a shoot on to an
endless band, which conveys it away in the manner herein-before described.
The hydraulic machinery consists of two or more, but we prefer six hydraulic
jacks which but on brackets attached to the interior of the leading chamber, and
their rams engage into ratchet teeth provided on the head. Where four or more or
any other even number of jacks are used we divide them into pairs, in such a
manner that one of each pair acts whilst the ram of the other is being drawn back,
the outward movement of one ram causing by means of chains or otherwise the
other ram to return into its cylinder. The head may however be actuated by
means of wheel gearing, screws, or other equivalent means in lieu of by hydraulic
pressure, and the details of the apparatus generally may be varied according to
circumstances.
An air or other suitable motive-power engine is employed for driving the
hydraulic machinery, boring the hole in front of and for the passage of the steering
pipe, and for imparting motion to the endless band.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Dickinson Brunton and George Brunton in the Great Seal
Patent Office on the 3rd October 1876.
JOHN DICKINSON BRUNTON and GEORGE BRUNTON, both of Leighton Crescent,
Kentish Town, in the County of Middlesex, Civil Engineers. "IMPROVEMENTS IN
TUNNELLING MACHINERY."
This Invention relates to improved combinations and arrangements of apparatus
to be employed in tunnelling, whereby the operations of boring the tunnel, guiding
and securing the machinery, and removing the materials excavated are performed
with facility in a rapid and efficient manner.
And in order that our said Invention may be fully understood we shall now
proceed more particularly to describe the same, and for that purpose shall refer to
the several Figures on the annexed Sheet of Drawings, the same letters of reference
indicating corresponding parts in all the Figures..
Figure 1 of the accompanying Sheet of Drawings represents a longitudinal section
of our improved tunnelling machine, and Figures 2, 3, and 4 arc transverse sections
of the same taken along the lines 1, 2, 3, 4, and 5, 6, respectively.
In carrying out our Invention we employ a revolving cutting head A', by
preference of a hemispherical shape, built up of plates B so bent and spirally
arranged and inclined that their protruding edges a form cutters, which as the head
revolves pare or cut away the chalk or other material being acted upon, spaces b
being left between the protuding edges a and the intruding edges c of the plates
or cutters B, through which spaces the material as it is excavated passes into the
interior of the head. The anterior portions of the plates or cutters are firmly
attached to a circular "centre piece" C, whilst the posterior portions are fixed to a
ring D which forms a journal for the head A. The interior of the "head" is divided
radially by plates d, so as to form with the rear part e of the plates B boxes or
buckets E, which as the "head" revolves receive the material removed by the
cutters.
The boxes or buckets E rise on the delivery side as the head rotates in the
direction of the arrow in Figures 2 and 3, and the material which has fallen into
them is prevented from being discharged prematurely by means of an overfall
plate F which extends upwards to a sufficient distance, and is then turned down, as
shewn at G, so as to form with other plates G1, G2, a shute for directing the debris
on to an endless band H. The endless band H is supported on rollers I carried in
the frame K, and is worked by a power engine at a sufficient velocity to convey
away all the material as fast as it is excavated, and deposit it into wagons provided
for its reception. This method of collecting and disposing of the material excavated
may be employed in connection with other descriptions of tunnelling machines.
In lieu of the arrangement of boxes or buckets herein-before described for
elevating the debris a series of scoops arranged obliquely on the circumference of a
conical drum may be employed, so as to work in contact with a semi-annular plate
forming a portion of the frustum of a cone, in such a manner that as the conical
drum revolves the scoops collect and carry up the material excavated, and discharge
it over the top edge of the semi-annular plate down a shute on to an endless band,
which conveys it away in the manner herein-before described.
The head A is caused to revolve by means of hydraulic machinery herein-after
referred to, and in order to facilitate the guiding or directing of the head in its
motion a steering pipe L is provided, which passes through the centre of the head,
and protrudes slightly from its exterior. This pipe rests in a spherical bearing M
formed on the centre picce C, herein-before referred to, so as to render it capable of
being moved in any required direction by means of adjusting screws and nuts f, f,
or by any other suitable means. A passage for the pipe L is made in the chalk or
other material, being operated upon in advance of the "head" by means of a screw

page_text: auger N arranged in the interior thereof, and driven from the engine herein-after
referred to by any convenient means, and the borings or debris formed by the screw
auger in its progess fall through openings in the pipe into the interior of the head,
and are conducted away by the endless band H.
We also employ in combination with the revolving head two or more expanding
chambers 0, 0¹, capable of being immoveably jammed in the tunnel at pleasure,
and of being separated or drawn towards each other, as required, in order to perform
the work.
The expanding chambers, which are constructed by preference of boiler plate, are
split or divided longitudinally at g in order to allow of their expansion, which we
accomplish by means of small hydraulic presses P. The expansion of the chambers
fixes or jams them tightly within the tunnel, and enables them to resist the
pressure necessary for the excavation, and for the moving of each other to and fro
as required within the tunnel. The chamber O¹ is arranged longitudinally behind
the other chamber O, and to the anterior portion of the leading chamber O thero is
firmly fixed a ring Q, into which the "head" ring D is introduced, and by which
the required position of the head is maintained and kept up to its work.
In the interior portion of the chamber O¹ there are fixed hydraulic jacks R, the
rams S of which are attached to the posterior portions of the leading chamber O, or
vice versa, and the jacks are so constructed that by altering the direction of the
water they may be made to draw the chambers closer to each other, or to separato
them as required. The chamber which for the time being is acting so as to draw
or push the other chamber is expanded within the tunnel, so as to maintain it
stationary, whilst the chamber which is being drawn or pushed is allowed to
contract in order to facilitate its motion. By this means as the cutting proceeds
the apparatus is caused to advance, and thereby keep the cutting head up to its
work.
To the lower outer system of the chambers 0, 0¹, there are attached keel pieces h,
the object of which is to plough up a groove in the interior surface of the tunnel
for their own passage, and in which they may be imbedded in order to resist the
tendency of the hydraulic jacks to turn the chambers when the head is being
rotated.
The hydraulic machinery for effecting the rotation of the head A consists of two or
more (we prefer six) hydraulic jacks T, which abut and oscillate on brackets i
attached to the interior of the chamber O, and their rams k engage into the ratchet
teeth fitted or formed on the ring D of the head A. When four or any other
even number of jacks are employed we divide them into pairs, and connect each
pair together by means of a chain m in such a manner that the outward movement
of the ram of one of the pair of jacks causes the ram of the other jack to return
into its cylinder. The cutting head may however be actuated by means of wheel
gearing screws or other equivalent means in lieu of by hydraulic pressure, and the
details of the apparatus generally may be varied according to circumstances.
An air or other suitable motive-power engine U is employed for driving the
hydraulic machinery for actuating the screw auger, and for imparting motion to
the endless band, any suitable arrangements of connections for transmitting the
motion being employed, but which we have not considered necessary to illustrate.
Having now described and particularly ascertained the nature of our said Inven-
tion, and the manner in which the same is or may be used or carried into effect, we
would observe in conclusion that what we consider to be novel and original, and
therefore claim as the Invention secured to us by the herein-before in part recited
Letters Patent is,-
First. The employment in tunnelling machines of a rotating cutting head
provided with buckets for clevating and discharging the debris, in combination
with a directing or steering tube and screw auger, the whole constructed, arranged,
and operated substantially in the manner herein-before described and as illustrated
by our Drawings.
Second. Effecting the longitudinal traverse of a tunnelling machine by means

page_text: of two or more expanding and contracting chambers arranged and operated substan-
tially in the manner herein-before described and illustrated by our Drawings.
In witness whereof, I, the said John Dickinson Brunton, on behalf of myself
and the said George Brunton, have to this our Specification set my hand
and seal, the Second day of October, One thousand eight hundred and
seventy-six.
JOHN DICKINSON BRUNTON. (L.S.)