IMPROVEMENTS IN EXCAVATING OR TUNNELLING MACHINES
Year: 1882

page_text: LETTERS PATENT to Thomas Russell Crampton, of No. 4, Victoria Street, in
the City of Westminster, for an invention of "IMPROVEMENTS IN EXCAVATING
OR TUNNELLING MACHINES."
PROVISIONAL SPECIFICATION left by the said Thomas Russell Crampton
at the Office of the Commissioners of Patents on the 27th April 1882.
THOMAS RUSSELL CRAMPTON of No. 4 Victoria Street in the City of Westminster
"IMPROVEMENTS IN EXCAVATING OR TUNNELLING MACHINES."
This Invention has for its object improvements in excavating or tunnelling
machines.
My machinery is adapted to work in chalk or other substance of a like nature
admitting of similar treatment. It operates by means of disc cutters so mounted
on a face plate or on arms as to roll in concentric rings along the face of the work.
The main axis is carried in bearings upon a bed moveable along a stationary
platform and suitably driven preferably by an hydraulic motor. The head having
radial arms or it may be of a disc like form is mounted upon the end of the axis.
The head carries disc like cutters these may be about six or eight inches in
diameter and they are mounted upon spindles or axes which are received into
sockets fixed upon the head. The disc cutters are set with their planes inclined at
a small angle to the working face. The cutters near the periphery of the head are
so inclined that the part of the disc cutter furthest from the main shaft comes
against the working face and is the operating part whilst some of the cutters near
the centre are inclined the opposite way so as to cut on the side nearer the centre.
As the main shaft revolves each disc cutter operates continuously upon the face
in its own circular track which is of a width about equal to one quarter of the
diameter of the disc and removes a thickness dependent on the forward movement
of the machine.
The discs are so set that the track of one cutter is close adjacent upon the track
of another so that the whole working face is travelled over by the cutters during

page_text: one revolution of the axis. The innermost cutter is so set as to cut to within a
short distance of the centre so as to leave uncut only such a piece as will break
down of itself. The disc cutters being free to revolve work as already stated with
a rolling movement which brings every part of the edge into successive operation
in a manner which is found very favorable to the maintenance of the edges in good
working order. Cutters so mounted when operating on chalk I find to work
efficiently both at high and low velocities thus those near the periphery of the
head may be carried round at a speed of 1000 feet a minute or even more, whilst
those near the centre will necessarily be carried on at a much slower rate.
Nevertheless both will act efficiently.
The sockets into which the spindles or axes of the disc cutters are received may
be kept lubricated and free from dust by means of water supplied under pressure
to the inner end of the socket. The water may be taken from the main by which
the hydraulic motor is supplied, and when such a motor is used I make use of the
pressure of the water in the main to force the machine forward towards the
working face. For this purpose I provide a ram attached to the bed of the
machine and entering the pressure main by a joint which is kept tight by leathers or
other usual appliances. To regulate the forward-movement, restraining and aiding
it as may be required, I provide a pinion or worm engaging with a fixed-rack-;-and-
this pinion or worm is geared with the main shaft so as to compel it to turn at a
suitable relative speed. The platform and rack are constructed in pieces so that a
portion of the rack and platform when the machine has passed over it may be
-removed to the front and there fixed to permit the continued forward movement
of the machine.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Thomas Russell Crampton in the Great Seal Patent Office on
the 27th October 1882.
THOMAS RUSSELL CRAMPTON of No. 4 Victoria Street in the City of Westminster.
"IMPROVEMENTS IN EXCAVATING OR TUNNELLING MACHINES."
This Invention has for its object improvements in excavating or tunnelling
machines.
My machinery is adapted to work in chalk or other substance of a like nature
admitting of similar treatment. It operates by means of disc cutters so mounted
on a face plate or on arms as to roll in concentric rings along the face of the work.
The main axis is carried in bearings upon a bed moveable along a stationary plat-
form and suitably driven, preferably by an hydraulic motor. The head having
radial arms, or it may be of a disc like form is mounted upon the end of the axis.
The head carries disc like cutters these may be about six or eight inches in
diameter or other convenient size and they are mounted upon spindles or axes
which are received into sockets fixed upon the head. The disc cutters are set
with their planes inclined at a small angle to the working face. The cutters near
the periphery of the head are so inclined that the part of the disc cutter furthest
from the main shaft comes against the working face and is the operating part;
whilst some of the cutters near the centre are inclined the opposite way so as
to cut on the side nearer the centre.―
As the main shaft revolves each disc cutter operates continuously upon the face
in its own circular track which is of a width about equal to one quarter of the
diameter of the disc and removes a thickness dependent on the forward movement
of the machine. The discs are so set that the track of one cutter is close adjacent
upon the track of another so that the whole working face is travelled over by
the cutters during one revolution of the main axis of the machine. The inner-
most cutter is so set as to cut to within a short distance of the centre so as to
leave uncut only such a piece as will break down of itself. The disc cutters
being free to revolve, work as already stated, with a rolling movement which
brings every part of the edge into successive operation in a manner which is
found very favourable to the maintenance of the edges in good working order.
Cutters so mounted when operating in chalk I find to work efficiently both at
high and low velocities, thus those near the periphery of the head may be carried
round at a speed at their cutting edges of 1,000 feet a minute or even more,
whilst those near the centre will necessarily be carried on at a much slower rate.
Nevertheless both will act efficiently.
The sockets into which the spindles or axes of the disc cutters are received may
be kept lubricated and free from dust by means of water supplied under pressure
to the inner end of the socket. The water may be taken from the main by which
the hydraulic motor is supplied, and when such a motor is used I make use of the
pressure of the water in the main to force the machine forward towards the
working face. For this purpose I provide a ram attached to the bed of the
machine and entering the pressure main by a joint which is kept tight by leathers
or other usual appliances. To regulate the forward movement, restraining and
aiding it as may be required, I provide a pinion or worm engaging with a fixed
rack; and this pinion or worm is geared with the main shaft so as to compel it to
turn at a suitable relative speed. The platform and rack are constructed in pieces
so that a portion of the rack and platform when the machine has passed over it
may be removed to the front and there fixed to permit the continued forward
movement of the machine.

page_text: In order that my invention may be fully understood and readily carried mo
effect I will proceed to describe the drawings hereunto annexed.
DESCRIPTION OF THE DRAWINGS.
Figure I is an elevation, Figure 1I a plan and Figure III an end view of a
tunnelling machine constructed according to my Invention.
A is a face plate with arms, attached to the main shaft B which is actuated by
a hydraulic or other motor C, either direct or by the interposition of gearing.
The whole is placed upon a frame D supported on wheels or on a sliding bed.
EEE are the pieces of platform and rack temporarily jointed together but which
can bo readily detached to allow of the same being taken up in rear of the machine
and removed to the front and relaid there.
This is effected as follows:-The portion E¹. of the platform (i.e. the rails and
sleeper) and rack over which the machine has last passed is unfastened, slightly
raised and attached to a lever F which is pivotted at the centre of the tunnel to
the frame of the machine. The lever is then swung round by a crab or any
convenient-means-until-the-portion El. reaches the position shewn by dotted lines
in Figures III and II. The rails G-G-and trucks. Hare then pulled back into
the position shewn by dotted lines in Figure I the portion E. is then lowered
upon the trucks or frames H, the lever is detached and the rails, trucks and
portion E. are pushed forwards until the rails are in their original positions. The
trucks with the portion E. suspended on thein are then pushed forwards on the
rails until they reach the position h Figure I so that the portion E, is clear of
main frame of the machine at the front. A similar lever F. at the front of the
machine is then attached to the portion E'; the rails with the trucks are pulled
-back-as-before-clear of the portion E' which is then swung down being supported
by the lever F and is dropt into position in front of the machine where it is-
firmly attached to the portion last laid. The trucks are then run back to the
other end of the rails and the rails and truck are pushed forwards together as
shewn in full lines so as to allow the succeeding portion to be raised. This can be
dono without stopping the forward motion (hereinafter described) of the machine
as the portions when attached to each other form a continuous railway and rack.
For the sake of illustration the Drawings shew one portion E¹ ready to be
removed and another at the other end of the machine which has just been laid,
this however would not occur in practice as the two portions would not be
simultaneously in these positions.
In Figures IV and V are shewn the face plate A and the cutting discs numbered
for convenience from 1 to 29.
In order better to shew the way in which the cutter discs are set I shew in
Figures VI and VII a plan and elevation of one of the cutters when in its highest
position. It will there be seen that the projections C. D, of the axis of the cutter
in the two figures each make angles of 18° as shewn to an imaginary line A B
which is perpendicular to the face plate.
In Figure IV the part of the edge of each cutter which enters the chalk is
indicated by a dark line.
The angles at which the cutters are set may however be varied according to
circumstances.
I prefer to set the cutter discs so that the extremities of their cutting edges all
lie in a plano at right angles to the axis of the face plate as is shewn in the
Drawings but some of them may be placed more forward than the others.
As the face plate turns in one direction, the cutting discs will turn in the
opposite sense as shewn by the arrows in Figure IV. The distances between the
dotted rings in that figure indicate the extent of the cut of each disc. In this
figure the discs numbered 1. 2 and 3 are shewn to cut with their inner edges, that
is, towards the centre; while the remainder 4 to 29 cut with their outer edges,

page_text: that is, towards the periphery. The change from one direction to the other is
clearly marked at the points M M in Figure V, it is of course quite immaterial at
which point such change takes place. The discs at the centre are shewn smaller
than the others but they may all be of the saine size.
In Figures VIII and IX is shown the arrangement by which water from the
hydraulic supply may be used for lubricating the spindles of the cutting discs, the
water at the same time also preventing the entrance of any dust into the socket.
a is a cutting disc, b its spindle, c the socket in which it turns which may be lined
if desired with hard wood or any other suitable substance. The socket is attached
to the arm or face plate in any convenient manner. d is a pin to keep the cutting
disc in its place by means of a groove cut in the spindle. c is a pipe with cock
attached to supply and regulate the water, which is introduced through the central
axis of the machine, through a hollow mainshaft or otherwise. The water is thus
made to enter each socket, it passes along the benring and makes its exit at f
whence it passes into the debris. If necessary a spiral groove may be made around
the spindle b.
The machine is caused to advance as follows.-J is a main fixed in the tunnel
for supplying fluid under pressure J¹ is a tube fixed to the main frame of the
machine and conveying the Huid to the motor C. It works telescopically on a
tube J, on the end of J the joint being kept tight by ordinary means. The pressure
of the fluid causes J' to act as a ram by which the machine is forced forwards.
If the waste fluid from the motor has to be pumped back the return main cau
similarly be made to form a rain.
When the machine has advanced so far that J' is near to the end of its run as
shewn at N Figure I. the machine is stopped by closing a valvo near the motor,
the valves K, K', are closed, the junction L between J and J", is unscrewed, the
portion J¹¹ is then moved forwards on J', a small cock O, having been opened to
allow the water displaced by the ram to escape out of the telescope, another
portion of main equal in length to the run of the ram is then inserted, the junctions
are made the small cock O, is closed, the valves K. K'. are opened and the motor
can be started.
The mode of controlling and regulating the advance of the machine is shewn on
Figures I. II and III. there is a worm P on the main shaft which engages with the
worm.wheel Q which by means of another worm R and worm wheel Š genrs with
a pinion T, which works in to the fixed rack E thereby regulating the forward
movement of the machine restraining or aiding it as may be required. The gearing
can be altered according to the rate of advance required.
Having thus described, the nature of my said Invention and the manner of
performing the same I would have it understood that I do not claim rotating
cutting discs for purposes of excavation as this is well known nor do I confine
myself to the particular mode of working here indicated but that what I do.
claim is :-
First. The use of rotating cutting discs, turning each on its own axis in
suitable bearings and placed upon a face plate in such a manner that each disc
will remove a concentric ring from the face of the excavation distinct and separate
from any other such ring cut by another disc substantially as described.
Second. Lubricating the spindles of the cutters with water or other suitable
liquid which is forced along the spindle and makes it exit at the front so as to
prevent the entrance of dirt substantially as described.
Third.-Constructing the main for the supply or return of the fluid for working
the machine to form a ram so that the pressure of the fluid in the main tends to
force the machine forwards substantially as described.
Fourth. The use of a rack or its equivalent and gearing attached to the
machine by means of which the forward movement of the machine, given by the
pressure of the incoming fluid can be controlled and regulated substantially as
described.

page_text: Fifth. The ineans of removing carrying forward and relaying the portions of
platform and rack substantially as described.
Sixth. The construction of excavating or tunnelling machines substantially as
described.
In witness whereof I the said Thomas Russell Crampton have hereunto set my
hand and seal this Twenty seventh day of October in the year of our Lord
One thousand eight hundred and eighty two,
T. R. CRAMPTON (L.S.)