IMPROVEMENTS IN MACHINERY OR APPARATUS FOR TUNNELLING, SHAFT SINKING, AND EXCAVATING
Year: 1881

page_text: LETTERS PATENT to John Dickinson Brunton, of Great George Street, in the
City of Westminster, for an Invention of "IMPROVEMENTS IN MACHINERY
OR APPARATUS FOR TUNNELLING, SHAFT SINKING, AND EXCAVATING."
PROVISIONAL SPECIFICATION left by the said John Dickinson Brunton at
the Office of the Commissioners of Patents on the 23rd September 1881.
JOHN DICKINSON BRUNTON, of Great George Street, in the City of Westminster.
"IMPROVEMENTS IN MACHINERY OR APPARATUS FOR TUNNELLING, SHAFT SINKING,
AND EXCAVATING."
My Invention has reference to improvements in tunnelling machinery of the
typo of what are known as Brunton's tunnelling machine, and it consists:-First,
of an improved method of supporting the tunnelling machine in the tunnel so as
to render it more steady, and at the same time not necessarily to interfere with its
continuous progression; secondly, of an improved method of lubricating the chucks
and parts adjacent thereto; thirdly, of an improved mode of applying water
when required to the face of the tunnel while excavating; fourthly, of certain
improvements in the details of the construction and arrangement of the chucks
and cutters, as hereinafter described.
In carrying out this Invention I substitute for the two side beams with their
wheels, as ordinarily employed in the class of apparatus herein before referred to,
whether resting on rails or on the surface of the tunnel, two side beams supported
by foot plates or feet arranged and operated in the following manner :-
The side beams are each provided with two pairs of sliding pieces held by and
moving in guides in the interior of the said beams, and projecting for a part of
their length at each end. Each sliding piece is raised or lowered, or held in any
desired position in the side beams by a screw or screws, which can be actuated
either by hand or by automatic motion from the prime mover, and each pair of
sliding pieces is connected to a foot capable of resting on the internal surface of
the tunnel, as hereinafter described. I prefer to fix wormwheels upon the upper
ends of the screws, and to command each pair of slides, that is to say, the two slides
FD 031

page_text: which are in line with one another and carry the same foot by one shaft carrying
corresponding worms, and thus to raise or lower the sliding pieces or slides of each
pair simultaneously. The longitudinal foot at the lower part of each pair of slides
is raised or lowered by means of the slides and screws, and from time to time rest
on the interior surface of the tunnel. Each pair of slides is capable of sliding
forwards upon its foot on guides formed upon the feet, and also carries a longitu-
dinal screw working in a nut attached to the foot, and by which the foot can
be caused to slide forwards upon the corresponding pair of slides, or this longitu-
dinal screw may be carried on the side beam and operate from thence on the foot.
In order to facilitate the manipulation I prefer to make this nut in two parts,
the upper part only being provided with a thread corresponding with the screw,
and by a belt or cord, or other suitable means to keep the screw constantly
rotating. When the upper half of the nut is raised out of gear the rotation of this
longitudinal screw has no practical effect either to advance the feet on the slides
or to prevent the advance of the slides on the feet.
The apparatus operates in the following manner :-Assuming that the tunnelling
apparatus is provided with four foct, the two outer feet, for example, are first
planted on the lower surface of the tunnel, and by turning the screws first men-
tioned the axis of the machine is brought into its proper central position, whilst
tho two inner feet are raised so as not to touch the tunnel surface. When thus
supported on the two outer feet the machine is set in motion and advances in its
work all the four pairs of slides, moving forwards with it, the two outer pair sliding
forwards upon their corresponding feet which remain stationary, whilst the two
inner pair of slides carry the inner pair of fect forward.
When the machine approaches the end of the distance intended to be accom-
plished while resting upon the external pair of feet, the half nuts, corresponding
to the inner pair of feet, are brought down and caused to engage with the corre
sponding longitudinal screws, with the immediate result that the said inner pair of
feet aro carried forwards to tho requisite advanced position, and at the proper
moment are screwed downwards by the screws first mentioned acting through the
slides until they relieve the outer pair of feet of the weight of the machine, and in
their turn sustain this weight as the unachine continues to advance. As soon as
the outer pair is thus relieved these feet are raised and brought forward, and in
their turn again take tho weight of the machine, and so on alternately, the
operation of the transference of the weight of the machine from one pair of feet
to the other necessitating no interruption of the progress of the work.
In some cases only one pair of feet may be employed, either the outer or inner
pair being dispensed with. In such cases I cast in the side of the side beam strong
Jugs provided with screws carrying and resting on suitable foot plates. By means
of the screws the weight of the machine is taken up (the foot plates resting in the
surface of the tunnel), and it is maintained in its place while the feet are raised
and advanced, as in the arrangement hereinbefore described. With such an
arrangement however the working and advance of the machine is necessarily
intermittent, as it must be stopped while advancing and readjusting the feet.
In lieu of screws herein before described hydraulic presses may be employed for
ncluating the slides and feet, and also for effecting the horizontal or longitudinal
motions of these parts of the machine. By the employment of hydraulic presses
the continuous forward motion of the machine is obtained with great facility in
the following manner, vis. A set of inner perpendicular presses is employed to
move the inner pair of feet in a plane at right angles to the axis of the tunnel,
and a corresponding set of outer perpendicular presses is employed to impart the
same motion to the outer pair of feet. A set of inner longitudinal presses imparts
motion in a direction parallel with the axis of the tunnel to the inner pair of feet,
and a set of outer longitudinal presses imparts similar motion to the outer pair of
feet. Assuming that the machine is at work, and supported for the time being
upon the inner pair of feet, for example, and has thus advanced a certain distance
forwards, a tappet on one of the corresponding slides comes in contact with a lever,

page_text: and thereby causes the outer pair of feet to be brought to bear upon the surface of
the tunnel by reversing the valves of the outer perpendicular presses.
At this moment the machine being on the point of reaching the limit of its
forward motion upon the inner feet another tappet causes this pair of feet to be
lifted off the surface of the tunnel by reversing the valves of the inner perpen-
dicular presses, and the machine is then enabled to continue its forward motion
without interruption upon the outer pair of feet, whilst at the same time
continuous pressure of water in the inner longitudinal presses serves to bring the
inner feet forward in readiness to again support the machine ns before, and so on
in succession; compressed air may be employed in the presses in lieu of water, or
may be caused to impart the required pressure to the water, and in this case the
pressure may be increased if necessary by employing pistons of differential areas
between the two fluids.
The slides or supports may be provided with rollers running on the upper
surfaces of the feet or foot plates in order to reduce the friction in lieu of being
caused to slido.on guides on the said plates, as hereinbefore described.
For the purpose of lubricating the apparatus I use a solution of soap and soda
in water, and in order to convey it to the parts of the machine to be lubricated
I surround the main central screw of the machine with a collar, having a hollow
space all round its interior. This collar does not revolve with the screw, but is
held stationary by any convenient attachment to the back carriage or frame of the
machine, and is placed in communication by means of a suitable tube with a
reservoir containing the solution of soap and soda in water. Circular glands
enclosing any suitable packing material, so as to constitute a stuffing box, are
employed for the purpose of preventing leakage on each side of the collar.
From the hollow space in the collar hereinbefore described I carry a tube
through a hole in the body of the main screw, and along the interior of the said
screw to the crosshead, and thenco through the centre of the chuck pivot to the
interior of the chuck, which latter is filled or partly filled with the solution. From
the interior of the chuck the solution is conducted by appropriate channels to the
cutter spindle bearings and to the chuck pivot which are the parts chiefly designed
to be lubricated by this means.
In order to apply water to the face of the tunnel I employ the improved
arrangement next hereinafter described. Surrounding the main screw, and working
against a face forming a water tight joint (being pressed against the said face by
means of small springs embedded in the frame of the machine), I place a ring
which does not revolve and which communicates by means of a tube and socket
with a reservoir of water under sufficient pressure. I hollow the face of the ring
through an arc of, say, about one hundred and twenty degrees, and to each arm
of the delivery drum which revolves independently of the main screw I attach a
tube communicating by a hole through the boss of the drum with the water
contained in the hollow space in the ring hereinbefore described, and which is so
arranged that the arc shall extend to, say, about 60° on one side and 60° on the
other side of a vertical lino passing through its centre.
As cach tube passes over the hollow in the ring hereinbefore described water is
forced through it and projected on to the upper part of the face of the tunnel,
whence the water descends over the whole face, but when the orifice leading to the
tube has passed the hollow are the tube is cut off from the supply. By this means,
with the least quantity of water possible, the surface of the rock is moistened
continually and dust is avoided. The surfaces of the bearings of the chuck pivot
are protected from dust by means of a strip of flexible material, such as leather,
india rubber, or felt, for example, attached to the frame of the machine and pressed
against the hinder part of the chuck by means of a spring or an india rubber ring,
and each cutter spindle is similarly protected by means of corresponding caps or
covers and rings or washers.
Scrapers are arranged between the cutters for the purposes of removing irregu-
larities in the sides of the tunnel and of throwing back the rubbish, in order to

page_text: enable it to be shovelled up by the scoops of the delivery drum with greater
facility.
When two cutting discs on one spindle are employed a pointed piece of stout
wire is attached to the chuck and bent round, so as to scrape or clean the angle
between the cutting edges of the two discs and prevent it from becoming clogged
with dust or fragments.
An arrangement for facilitating the exchange or removal of the cutters without
moving the machine away from the face of the rock consists in placing the cutters
at the back of the chuck.
The cutter spindles are provided at the rear end with a screwed flange in the
form of a cap, on to which the cutting discs are secured by means of a ring screwed
over the cap, and the point end of the said spindles may be provided with a bevel
wheel in gear with a bevel wheel fast on a shaft passing through the chuck pivot in
order to impart a positive motion to the cutter. A plate bolted to the front of the
chuck serves to protect the gearing from dust, and dust is likewise excluded from
the rear end of the cutter spindles by means of suitable packing interposed between
the flange hereinbefore described and the back of the chuck,

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Dickinson Brunton in the Great Seal Patent Office on the
23rd March 1882.
JOHN DICKINSON BRUNTON, of Great George Street, in the City of Westminster.
"IMPROVEMENTS IN MACHINERY OR APPARATUS FOR TUNNELLING, SHAFT SINKING,
AND EXCAVATING."
My Invention has reference to improvements in tunnelling machinery of the
type known as Brunton's tunnelling machine, and it consists, first, of an improved
method of supporting the tunnelling machine in the tunnel so as to render it more
steady; secondly, of an improved method of lubricating the chucks and parts
adjacent thereto; thirdly, of an improved mode of or means for applying water
when required to the face of the tunnel while excavating; fourthly, of certain
improvements in details as hereinafter described.
According to the first part of this Invention I substitute for the two side beams:
with their wheels (resting on rails or on the surface of the tunnel) as ordinarily.
employed in the class of apparatus herein before referred to, two side beams
supported by foot plates or feet arranged and operated in the following manner :-
The side beams are each provided with two pairs of sliding pieces held by and
moving in guides in the said beams, and each sliding piece is raised or lowered to
any desired position in the said beams and held in that position by a screw or
screws which can be actuated either by hand or automatically from the primo
mover, and each pair of sliding pieces is connected to a foot capable of resting on
the internal surface of the tunnel as hereinbefore described. I prefer to fix worm
wheels upon the upper ends of the screws and to operate each pair of slides (that
is to say the two slides which are in line with one another and which carry the
same foot) by one shaft carrying corresponding worms and to raise or lower tho
sliding pieces or slides of each corresponding pair on opposite sides of the main
line simultaneously. The longitudinal foot at the lower part of each pair of slides.
is raised or lowered by means of the slides and screws and from time to time rest
on the interior surface of the tunnel. Each pair of slides is capable of sliding.
forwards upon guides formed upon the feet and also carries a longitudinal screw.
working in a nut attached to the foot by which the foot can be caused to slide
forwards upon the corresponding pair of slides, or this longitudinal screw may be
carried on the side beam and operate from thence on the foot. In order to
facilitate the manipulation I prefer to make this nut in two parts, the upper part
only being provided with a thread corresponding with the screw which is provided
with means for keeping the screw constantly rotating. When the upper half of
the nut is raised out of gear the rotation of this longitudinal screw has no
practical effect either to advance the feet on the slides or to prevent the advanco
of the slides of the feet.
The apparatus operates in the following manner :-
Assuming as an example that the tunnelling apparatus is provided with four
feet, two feet (one on either side of the machine) aro planted on the lower surface
of the tunnel, and by turning the screws first mentioned the axis of the machine
is brought into its proper central position whilst the two other feet are raised.
so as not to touch the tunnel surface. When thus supported on two feet the
macbine is set in motion, and as it advances in its work it carries forward with it
all the four pairs of slides, those of the feet which rest on the tunnel sliding
forward upon the said feet which remain stationary, whilst the two other pair of
slides carry the raised pair of feet forward with them as the machine procceds.
When the machine approaches. the end of...the distance. intended to bẻ.

page_text: accomplished while resting upon the lowered pair of feet, the half nuts,
corresponding to the raised pair of feet, are brought down and caused to engage
with the corresponding longitudinal screws, with the immediate result that the
said pair of feet are carried forward upon their slides to the requisite position in
advance of the other pair of feet, and at the proper moment are screwed downwards
hy the screws just mentioned acting through the slides until the said feet bear
upon the face of the tunnel and relieve the other pair of feet of the weight of the
machine and in their turn sustain this weight as the machine continues to advance.
After the relieved pair of feet are raised they are carried forward as described
with regard to the other pair, and in their turn again take the weight of the
machine, and so on alternately, the operation of the transference of the weight
of the machine from one pair of feet to the other necessitating no interruption of
the progress of the work.
In some cases only one pair of feet may be employed, either the outer or inner
pair being dispensed with. In such cases I cast in or fix to the side of the side
beam strong lugs provided with screws carrying and resting on foot plates. By
means of the screws the weight of the machine is taken up (the foot plates resting
on the surface of the tunnel) and it is maintained in its place while the feet are
raised and advanced, as in the arrangement herein before described. With such an
arrangement however the working and advance of the machine is necessarily
intermittent, as it must be stopped while advancing and readjusting the feet.
Instead of screws hereinbefore described hydraulic presses may be employed for
raising and lowering the slides and feet, and also for effecting the horizontal or
longitudinal motions of these parts of the machine. By the employment of
hydraulic presses the continuous forward motion of the machine is attained with
great facility in the following manner:-A set of inner perpendicular presses is
employed to move the one pair of feet in a plane at right angles to the axis of the
tunnel, and a corresponding set of outer perpendicular presses is employed to
impart the same motion to the other pair of feet. A set of inner perpendicular
presses is employed to impart motion in a direction parallel with the axis of the
tunnel to the one pair of feet, and a set of outer longitudinal presses imparts similar
motion to the other pair of feet.
The slides or supports may be provided with rollers running on the upper surfaces
of the feet or foot plates in order to reduce the friction.
For the purpose of lubricating the apparatus I use a solution of soap or soap and
soda in water, and in order to convey it to the parts of the machine to be lubricated
I surround the main central screw of the machine with a collar having a hollow
space all round its interior. This collar does not revolve with the screw, but is
held stationary by any convenient attachment to the back carriage or frame of the
machine, and is placed in communication with a reservoir containing the solution of
the soap and soda in water. Circular glands enclosing packing material are
employed for the purpose of preventing leakage on each side of the collar.
From the hollow space in the collar I carry a tube through a hole in the body of
the main screw, and along the interior of the suid screw to the cross-head, and
thence through the centre of the chuck pivot to the interior of the chuck, which
latter is filled or partly filled with the solution. From the interior of the chuck
the solution is conducted by channels to the cutter spindle bearings, and to the
chuck pivot, which are the parts chiefly designed to be lubricated by this means.
In order to apply water to the face of the tunnel I employ the improved arrange-
ment next hereinafter described. Surrounding the main screw and working against
a face forming a water-tight joint (being pressed against the said face by means of
springs embedded in the frame of the machine), I place a ring which does not revolve
and which communicates with a reservoir of water. I hollow the face of the ring
through an arc of, say, about one hundred and twenty degrees, and to each arm of
the delivery drum, which revolves independently of the main screw, I attach a
tube communicating by a hole through the boss of the drum or the wheel by which
the drum is rotated with the water contained in the hollow space in the ring

page_text: herein before described. The ring is so placed that the hollow therein is at the upper
part, and as each tube passes over the said hollow in the ring water is forced through
it and projected on to the upper part of the face of the tunnel, whence the water
descends over the whole face, but when the orifice leading to the tube has passed
the hollow are the supply of water is cut off. By this means, with the least
quantity of water possible, the surface of the rock is moistened continually, and
dust is avoided. The surfaces of the bearings of the chuck pivot are protected from
dust by means of a strip of flexible material, such as leather, india-rubber, or felt,
for example, attached to the frame of the machine and pressed against the hinder
part of the chuck. Each cutter spindle may be similarly protected.
Scrapers aro arranged between the cuttors for the purposes of removing
irregularities in the sides of the tunnel, and of throwing back the rubbish in order
to enable it to be shovelled up by the scoops of the delivery drum with greater
facility.
When two cutting discs on one spindle are employed, a pointed piece of stout
wire is attached to the chuck and bent round, so as to scrape or clean the anglo
between the cutting edges of the two discs, and prevent it from becoming clogged
with dust or fragments.
An arrangement for facilitating the exchange or removal of the cutters without
moving the machino away from the face of the rock consists in placing the cutters
at the back of the chuck. The cutter spindles are provided at the rear end with a
screwed flange in the form of a cap, on to which the cutting discs are secured by
means of a ring screwed over the cap, and the forward end of the said spindles may be
provided with a bevel wheel in gear with a bevel wheel fast on a shaft passing
through the chuck pivot in order to impart a positive motion to the cutter. A plate
bolted to the front of the chuck serves to protect the gearing from dust, and dust is
likewise excluded from the rear end of the cutter spindles by means of packing
interposed between the flange herein before described and the back of the chuck.
And in order that my said Invention may be fully understood I shall now proceed
more particularly to describe the same, and for that purpose shall refer to the
several Figures on the annexed Sheets of Drawings, the same letters of referenco
indicating corresponding parts in all the Figures.
Figure 1 of tho accompanying Drawings is a longitudinal section, and Figure 2 a
transverse section of so much of a "Brunton's" tunnelling machine as is necessary
to illustrate the application thereto of my improvements in accordance with the
said first part of the Invention. The parts not shewn are or may be of the
construction common to such machines; Figure 3 is a longitudinal section of one
end of one of the parts of the framing and the foot carried by it and its adjuncts.
At each side of the framing of the machine and fixed thereto or forming part
thereof are double castings A, at either end of each of which is a sliding piece or
block B capable of being raised and lowered in the said castings A by means of
screws C, engaging with screw boxes in the said sliding pieces; the upper ends of
these screws are provided with worn wheels D, with which worms E on the shaft F
engage to give rotatory motion to the said screws for raising and lowering the
sliding pieces C. The lower part of the sliding pieces B is formed with slides, upon
which take and slide feet G, there being a pair of such feet at each end of the
machine, and each foot slides upon and is held by each pair (longitudinally
considered) of sliding pieces. There is a worm for each worm wheel and screw,
but in order to enable one worm shaft to operate the worms for both the pairs of
sliding pieces on the one side of the machine the following arrangement is
adopted-The worm shaft F for each side of the machine is situated between the
two pairs of sliding pieces, as shewn clearly in Figure 2; the worms, except as
hereinafter stated, are capable of revolving on the said shaft. The worms are
confined between lugs H from the framing. The worm wheels of the one
longitudinal pair of sliding pieces which support the one foot are set out of the
transverse plane of the worm wheels of the other pair of screws which support the
other foot. At each of the parts of the shaft F which extend through the worm

page_text: wheels a feather is formed of the same length as, or a little less than the length of
the space between two adjacent worms. In the said worms are corresponding
grooves. The position of each of these feathers on the same shaft with relation to
all of the pairs of worms with which they are used is the same, so that by sliding
the said shaft into one position the feathers engage with all the worms of the
screws which operate the sliding pieces of one of the feet, and on sliding the shaft
into another position the feathers engage with all the other worms, videlicet, thoso
of the screws which operate the sliding pieces of the other foot on the same side of
the machine. It will be understood that this arrangement is the same with each
pair of feet on either side of the machine, also that the arrangement (which I now
proceed to describe with regard to one foot) for feeding forward to a new position
the feet when raised is applied to each of the feet on both sides of the machine.
Turning in bearings in the frame A is a screwed shaft I (see Figure 3-and the left
hand side of Figure 2). Upon the foot is a standard or bracket piece K, between
the horns of which the screw shaft passes. Above the said shaft is a half nut L,
capable of being raised and lowered in or upon these horns which constitute guides
therefor. This raising and lowering is effected by any convenient means, for
example, by levers attached to the shafts M turning in bearings in the frame,
which shafts by the said levers are turned, and through arms N and connecting
links are caused to effect the raising or lowering of the said half nuts. The said
arms N are attached to the shaft by a groove and feather or equivalent means, so
that they turn with the said shafts but are free to run thereupon in order to
follow the motion of the half nuts. The screw shafts I receive motion of rotation
from any convenient rotating part of the machine, they being provided with
gearing or belt pulleys for receiving such motion.
Then when the half nut is lowered into the screw the said screw causes the said
nut and the foot with which it is connected to be moved forward upon its guides
on the sliding pieces B of the said foot.
When the machine is in operation one of the feet on each side of the machine is
in its lowered position to rest upon the sides of the tunnel and support the machine,
the other of the feet on each side of the machine being held by its slides in a raised
position. As the machine travels forward the sliding pieces B of the depressed feet
slide on the said feet, the frame carrying forward with it the raised foet. When
the machine has travelled forward the requisite distance upon the depressed feet,
the half nuts of the pair of raised feet are brought down upon their corresponding
screws, so that the raised feet to which the said nuts are attached are moved
forward in advance of the feet upon which the machine at this time is resting.
The shafts F are then moved into such a position that their feathers engage with
the worms of the screws which are upon the slides of the raised pair of feet, so
that the said feet are lowered to bear upon the sides of the tunnel and relieve the
other feet. The said shaft is then moved so that its feathers are disengaged from
the said worms and are engaged with the worms of the other pair of feet, which
worms are thereby caused to so operate upon the worm wheels E of that pair as
to cause the screws C to raise the said pair of feet. The machine then travels
forward upon this depressed pair of feet carrying with it the other raised pair,
which are afterwards moved forward in advance of the depressed pair and then
lowered to take the weight of the machine, the other pair being then raised and
carried forward and so on alternately, the said feet by acting in this step by step
manner causes the machine to travel forward upon first one pair of feet and thon
upon the other pair of feet as it proceeds with the cutting of the tunnel. The
shafts may be rotated by hand, or they may be connected by gearing and a clutch
arrangement with a rotating part of the machine so as to be operated therefrom at
the required periods.
In order to facilitate the engagement of the feathers on the shaft F with the
worms which it is necessary to operate at one time, the face of each worm on the
side at which the feather enters has a spiral form, as shewn in Figure 3ª, where 15
shows the spiral face and 16 the groove which-receives the feather of the shaft,

page_text: the side of which groove is in line or flush with the projecting end or tooth 17
formed by the highest part of the spiral. Thus by turning the shaft in tho
direction of the arrow all the feathers on the shaft are eventually brought up
against all the teeth 17 of the spiral faces of the worms, and in that position can
readily enter the grooves 10. In place of operating the worm wheels of both feet
on the same side of the machine by a single shaft F placed between them, each
foot may be operated upon by separate shafts, as indicated by dotted lines at F¹
and Fu
Figure 4 represents a modification wherein only a single pair of feet is employed,
one foot at each side of the machine. The arrangement at one side only is shewn,
but it will be understood that a similar arrangement is provided at the other side;
also the main body of the machino is omitted from this figure, but the beam A is
part of or fixed to the framing of the machine, as before described. A strong lug O
is cast or fixed to the side beam, and in it runs a screw P carrying a foot
plate Q. When the feet are to be raised and move forward the action of the
machine is stopped, and the screws on either side of the machine are turned so as
to depress the plates Q against the sides of the tunnel and sustain the machine
whilst the feet are being raised and moved forward for the further action of the
machine. A strut or struts is or are provided to keep the machine from turning or
canting up as its cutters act, the said strut or struts being provided with a screw,
as at R, for wedging it in position and releasing it as required.
There may be any number of the lugs O, screws P, and plates Q in combination
with each foot, and in place of the screw P for depressing the plate hydraulic
pressure may be employed.
Figure 5 is a transverse section of a sliding piece provided with a wheel or
wheels, as at S, to run upon the foot to lessen friction.
Figure 6 is a similar section of a modified form of the apparatus illustrating
the application of hydraulic in place of screw power for raising and lowering the
sliding pieces carrying the feet. Above each sliding piece B a hydraulic cylinder T
is mounted, the ram of which is attached to the said sliding piece. Figure 7
illustrates a mode of applying bydraulic in place of screw power for feeding
forward the feet when they are in their raised position. U is a double acting
hydraulic cylinder affixed to the beam A, thero being a similar arrangement for
each foot. The ram or piston V of the cylinder is connected by its rod and
block W with a slotted piece X firmly bolted to the foot G. A passage is provided
for the acting water to one side of the ram, and another passage is provided for
the exit of the exhaust water from the other side of the ram, the said passages
communicating with a valve chest Y having a sliding valve, the rod of which can
be shifted into one or the other position by the lever Z to admit the water from
the supply pipe a and by the passage b to the one side of the ram of the cylinder,
the exbaust water passing from the opposite side of the ram by the passage c, and
passing from the cylinder through the valve and away from apparatus by a pipe
not shewn. The continuation of the rod of the ram is supported in a bracket
pieco d which is free to slide on the said rod. Thus when the machine is travelling
upon the feet, which are down, the cylinder U slides over the ram V and the
bracket piece d slides on the rod e. When it is required to press the feet forward,
water is admitted by the pipe b to the cylinder U when the ram is pressed forward,
and through its rode and block W moves forward the foot G, the rod e sliding
through the bracket piece d. The slot in the piece X allows the foot to be raised
with its sliding pieces. By admitting water by the passage the foot can be
moved in the opposite direction if required.
The valves which admits water to the various presses may be either acted upon
by hand, or, if desired, they may be acted upon by projections from the machine,
for example, as follows:-
Assuming that the machine is at work, and supported for the time being upon
one pair of feet (one foot at each side of the machine), and has thus advanced a
certain distance forward, a tappet on one of the corresponding slides comes in

page_text: contact with a lever, and thereby causes the elevated pair of feet to be brought to
bear upon the surface of the tunnel by reversing the valves of the perpendicular
presses in connection with that pair of feet. At this moment the machine, being
on the point of reaching the limit of its forward motion upon the first mentioned
pair of feet, another tappet causes this pair of feet to be lifted off the surface of
the tunnel by reversing the valves of the perpendicular presses in connection
therewith, and the machine is then enabled to continue its forward motion without
interruption upon the pair. of feet which are bearing upon the tunnel. By
admitting water to the longitudinal presses in connection with the elevated feet,
the said feet are brought forward in readiness to again s pport the machine, as
before, and so on in succession. Compressed air may be employed in the presses
instead of water, or may be caused to impart the required pressure to the water,
and in this case the pressure may be increased, if necessary, by employing pistons
of differential area between the two fluids.
In Figure 8 I have shown a longitudinal section of a portion of the main screw,
shewing the arrangement by which the apparatus is lubricated by soap and water,
or soap and soda and water.
The main screw is surrounded by a collar fhaving a space or channel & between
its interior and the exterior of the screw g. This collar does not revolve with the
screw, but is held stationary by being connected with any suitable part of the
machine. Glands at h enclose packing, and prevent leakage. This channel k is by
means of a tube i placed in communication with a reservoir containing the lubricant.
From the space the lubricant passes by the pipe through and along the body of
the main screw to the cross head, and thence through the centre of the chuck pivot
to the interior of the chuck by the branch passages m and o, which latter leads
from a groove formed all round the bearings of the chuck into the space or interior
of the chuck at n (shewn at Figure 9), which thus receives a supply of lubricant
which is conducted by the passages o¹, o¹, to the cutter spindle bearings.
The chuck pivot receives lubricant from the groove formed as before mentioned
around the 'chuck bearing.
In Figure 1 I have shewn the arrangement for supplying water to the upper
part of the face of the tunnel. Surrounding the main screw 9 is a ring P, shown
detached in face view in Figure 14, which does not revolve, and which has a
recess g of the form of an arc in the upper part of its side presented towards the
face of the tunnel. A pipe leading from a reservoir or source of water supply
under pressure communicates with this space. To each arm of the delivery drum 8
I attach a tube t secured at one end in a hole or passage through the toothed
wheel u, by which the drum receives its motion, each tubo t terminating at its
other end in a nozzle in proximity to the face of the tunnel. Although but two
tubes are shewn in the Drawing, yet it will be understood that a greater number
is or may be employed. As each opening v passes over or in front of the recess 7,
water passes through it and through the pipe and nozzle, and is projected over the
upper part of the face of the tunnel, and descends over the whole face. When the
openings have passed the recess q and come opposite the flat face of the ring p, no
water passes to the nozzles. The ring may be prevented from revolving by being
connected with any convenient part of the machine, and it may be pressed firmly
against the face of the wheel by means of springs, as at w.
The interior of the cross head is inclosed, and the surfaces of the bearings of the
chuck pivot thereby protected from dust by means of a strip or annular piece x
(Figure 9) of flexible material, such as india rubber, leather, or felt, extending
around the parts, the said strip being at one edge or side attached to the covering
plate y of the cross head by pins, as at z, the other side or edge being pressed all
round by a spring (which may be a tubular india rubber ring, as at 1) against the
hinder part of the chuck. Each cutter spindle is similarly protected by circular
strips or rings of felt or other suitable substance surrounding their collars, as at 14
in Figure 9.
Figure 10 is a front view of a part of a chuck, and Figure 11 is a tranverse section

page_text: shewing scrapers 2 arranged between the cutters 3 for removing irregularities in
the sides of the tunnels and throwing back the rubbish in order that it may be
removed with greater facility. The said scrapers are skewed so as to throw back
the rubbish. The position of the acting surface of these scrapers (of which thero
may be one between each two adjacent cutters) will be immediately to the rear of
the path of the cutters.
4 in Figure 9 represents a pointed pieco of stout wire which is attached to the
chuck covering plate, and bent round into a position between the two cutter discs
so as to scrape or clean the angle between the cutting edges of the two discs and
prevent it from becoming clogged. A similar cleaner will be used with each pair
of cutter discs, or between all adjacent cutters where. more than two cutters are
used on the same spindle.
Figure 12 represents the arrangement for facilitating the exchange or removal of
the cutters without moving the machine away from the face of the rock. The
cutter spindle 5 has upon its rear end a cup like termination 6, into which the
boss 7 of the arm of the chuck takes. This cap piece is screwed on its exterior
and has around it a flange 8. The cutters are placed at the back of the chuck
over this cap pieco and hear against the said flange; a wedge shaped ring 9 is
screwed upon the cap piece and firmly secures the cutters in place. To give a
positive motion to the cutters each cutter spindle carries a bevel pinion 10 in gear
with a bevel wheel or toothed ring 11 fast upon the shaft 12, passing through the
chuck pivot.
A plate, as shown at 13, can bo bolted over the front of the chuck to prevent
access of dust, the said plate being of a disc form, and affixed by screws or other-
wise to the arms of the chuck, as shown with regard to ono of them. A packing
ring 14 is placed in an annular groove, formed partly in the inner side of the cap
piece 6 and partly in the back of the chuck, which will keep dust out from the
cutter spindles.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried into
effect, I would observe in conclusion that what I consider to be novel and original,
and therefore claim as the Invention secured to me by the hereinbefore in part
recited Letters Patent is,-
First. In machinery or apparatus for tunnelling and the like, the employment of
fect upon which the machine rests, the said feet being raised and lowered
relatively to the machine itself, substantially as and for the purpose hereinbefore
described with reference to Figures 1 to 7 of the accompanying Drawings.
Second. The combination of double pairs of feet for the machine to travel upon,
so arranged and operated that the machine travels alternately upon one pair, and
the other as the said machine progresses with its work, substantially as described
and illustrated in Figures 1, 2, and 3 of the accompanying Drawings.
Third. The combination of single feet for the machine to rest and travel forward
upon with rests or supports, upon which the machine is supported whilst the feet
are fed forward for the further operation of the machine, substantially as herein-
before described with reference to Figure 4 of the accompanying Drawings.
Fourth. The means for effecting the lubrication of the chuck pivot or axis
and of the cutter spindle bearings, substantially as herein before described and
illustrated in Figures 8 and 9 of the accompanying Drawings.
Fifth. The means for applying water to the face of the tunnel, substantially
as hereinbefore described and illustrated in Figures 1 and 1ª of the accompanying
Drawings.
Sixth. The means for protecting the bearings of the chuck on its pivot or axis
and of the cutter spindles from dust, substantially as herein before described and
illustrated with regard to the protection of the chuck pivot in Figure 9 of the
accompanying Drawings, and with regard to the protection of the cutter spindles
in Figures 9 and 12 of the accompanying Drawings.
Seventh. The combination with the chuck and cutters of scrapers (2) arranged

page_text: and operating substantially as and for the purpose hereinbefore described and
illustrated in Figures 10 and 11 of the accompanying Drawings.
Eighth. The combination with two or more cutters carried by one spindle of the
scrapers or cleaners 4, as illustrated in Figure 9 of the accompanying Drawings
for the purpose described.
Ninth. The means for enabling the cutters to be placed at the back of the
chuck, substantially as and for the purpose described and illustrated in Figure 12
of the accompanying Drawings.
In witness whereof, I, the said John Dickinson Brunton, have to this my
Specification set my hand and seal, this Twenty first day of March, One
thousand eight hundred and eighty two.
JOHN DICKINSON BRUNTON. (LS.)