IMPROVEMENTS IN TUNNELLING MACHINERY
Year: 1875

page_text: LETTERS PATENT to Frederick Edward Blackett Beaumont, of No. 2,
Westminster Chambers, Victoria Street, in the County of Middlesex,
:
PROVISIONAL SPECIFICATION left by the said Frederick Edward
Blackett Beaumont at the Office of the Commissioners of Patents,
with his Petition,, on the 2nd December 1875.
I, FREDERICK EDWARD BLACKETT BEAUMONT, of No. 2, Westminster
Chambers, Victoria Street, in the County of Middlesex, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN TUNNELLING
MACHINERY," to be as follows:-
My Invention relates to machinery for driving tunnels or galleries in
soft rock, shales, or strata, such as chalk, by the scraping action of a
number of steel cutters. For this purpose I mount upon the end of a

page_text: revolving horizontal shaft a crown or head in the shape of two or more
radial arms, in which are a number of sockets for the reception of steel
cutters, the sockets and cutters being arranged in the form of steps
receding on each side from the centre of the head, so that when this is
brought against the face of the rock and rotated each cutter scrapes
away the face of the material in the form of a circular ledge or step
somewhat in advance of the next cutter outside of it, there being a
central cutter in the line of the axis of the boring shaft which cuts away
a central cylindrical recess. By this arrangement all the debris produced
by the cutters will readily fall to the bottom of the tunnel or gallery,
whence they can be removed by means of an endless band, or a screw or
creeper, such as is used in flour mills, delivering the debris into trucks
behind the carriage, or by workmen who can shovel it away when it has
fallen clear of the cutters. The shaft of the boring head is by preference
mounted on a carriage running on rails on the bottom of the gallery, on:
which carriage is a motor engine or set of engines imparting a slow
rotary motion to the boring shaft by suitable speed reducing gearing.
The advance of the boring head as the work proceeds may either be
effected by advancing the carriage on which it is supported, or by sliding
forward the shaft of the boring head by any known means.
For comparatively short headings the motion may be imparted to
the boring shaft by a wire or other rope worked by any suitable motor
outside.
For large tunnels, instead of using one boring head of the full size of
the tunnel, several such boring heads may be arranged to work parallel a
to each other, the portions of material left between the circular cuts of
the several heads being afterwards cut or broken away.
If it should be desired to equalise the speed of the cutters at their
various distances from the centre the boring head might be made up of
separate concentric circles, each having an increased speed of rotation as
it is nearer to the centre.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Frederick Edward Blackett Beaumont in the
Great Seal Patent Office on the 1st June 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FREDERICK
EDWARD BLACKETT BEAUMONT, of No. 2, Westminster Chambers,
Victoria Street, in the County of Middlesex, send greeting.
WHEREAS. Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Second day of December, in the
year of our Lord One thousand eight hundred and seventy-five, in the
thirty-ninth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Frederick Edward Blackett
Beaumont, Her special license that I, the said Frederick Edward
Blackett Beaumont, my executors, administrators, and assigns, or such
others as I, the said Frederick Edward Blackett Beaumont, my executors,
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 "IMPROVEMENTS IN
TUNNELLING MACHINERY," upon the condition (amongst others) that I, the
said Frederick Edward Blackett Beaumont, my executors or admini-
strators, 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 Frederick Edward Blackett
Beaumont, do hereby declare the nature of the said Invention, and in
what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement thereof, reference
being had to the accompanying Sheet of Drawings, and to the figures
and letters marked thereon, that is to say :-
°
-
My Invention relates to machinery for driving tunnels or galleries in
soft rock, shales, or strata, such as chalk, by the scraping action of a
number of steel cutters. For this purpose I mount upon the end of a

page_text: Upon the end of the shaft A is fixed the crown or head B formed
with steps b, b, in each of which is mounted a cutter C. These cutters
have each a broad cutting edge at c, so that as the boring head revolves
they cut or scrape away the face of the rock D in the form of steps, as
before described. The cutters are so formed that the outer edge thereof
projects somewhat beyond its base, as indicated, so that there is no
scraping action at the side of the cutter.
The form of the cutters may be variously modified to suit different
kinds of rock upon which the machine has to operate. Thus they may
be formed simply with a chisel edge slightly inclined forward in the
direction in which they rotate, as shewn at Figs. 2 and 3; or they may
be formed with a projecting beak, as shewn at Fig. 4, so as to act upon
the rock at a more acute angle.
The central cutter C¹ may be formed as an ordinary drill, as shewn.
=
As before stated the boring head may be mounted and driven in
various
ways..
One arrangement is shewn at Figs. 5, 6, and 7, which represent
respectively a longitudinal section, an end view, and a plan of the tunnel
driving machine.
The boring shaft A with its boring head B is mounted in bearings E¹, E³,
on the carriage E, the bearing Es being provided with thrust collars, as
shewn, while the advance of the carriage with the boring head as the
work of boring proceeds is effected either by a screw spindle bearing
against the carriage and against a fixed abutment behind the same, or
by any other known contrivance.
The rotation of the boring head is effected by means of any suitable
motor engine situated at the back of the machine, driving the pulley F
by a band or rope F¹, the pulley F being fixed on a shaft G having two
worms G¹, G', in gear with worm wheels H¹, H', on two shafts H, H,
carried by the carriage, which shafts have at their front ends spur
pinions H, H2, in gear with a spur wheel I fixed on the shaft A.
The debris, as they collect at the foot of the boring head, are removed
by an endless travelling belt K passing round a roller K' on the
carriage, which belt may extend back to the motor engine driving the
same, or to any convenient point where the belt may be made to deliver
the debris into trucks.

page_text: Having thus described the nature of my Invention, and in what
manner the same is to be performed, I claim, the use for driving tunnels
or galleries of a boring head consisting of two or more arms carrying
cutters arranged in the form of steps receding on each side from the
centre of the bead in such manner that by the rotation of the boring
head the rock will be cut away in the form of a series of concentric
circular ledges or steps, substantially as herein-before set forth.
In witness whereof, I, the said Frederick Edward Blackett
Beaumont, have hereunto set my hand and seal, this Thirteenth
day of May, in the year of our Lord One thousand eight-hundred
and seventy-six.
F. E. B. BEAUMONT. (L.S.)