AN IMPROVED EXCAVATING MACHINE FOR BORING TUNNELS AND PERFORMING OTHER EXCAVA-TING OPERATIONS
Year: 1860

page_text: LETTERS PATENT to Richard Archibald Brooman, of 166, Fleet Street,
in the City of London, Patent Agent, for the Invention of "AN IMPROVED
EXCAVATING MACHINE FOR BORING TUNNELS AND PERFORMING OTHER EXCAVA-
TING OPERATIONS."-A communication from abroad by Messrs Hippolyte
Amédée Buquet, and Raoul Jacques Marie Destrem, of Paris, and Jean
Baptiste Valauri, of Turin.
Sealed the 7th February 1861, and dated the 8th August 1860.
PROVISIONAL SPECIFICATION left by the said Richard Archibald Brooman
at the Office of the Commissioners of Patents, with his Petition, on the
8th August 1860.
I, RICHARD ARCHIBALD BROOMAN, of 166, Fleet Street, in the City of
London, Patent Agent, do hereby declare the nature of the said Invention for
"AN IMPROVED EXCAVATING MACHINE FOR BORING TUNNELS AND PERFORMING OTHER
EXCAVATING OPERATIONS," (communicated to me from abroad by Messrs.
Hippolyte Amédée Buquet, and Raoul Jacques Marie Destrem, of Paris, and
Jean Baptiste Valauri, of Turin,) to be as follows:-
This machine consists of a strong under carriage or bed mounted on wheels
or rollers, upon which a frame carrying an engine gear work, and the ex-
cavating tools hereafter described is free to be moved to and fro. The

page_text: excavating tools consist of a series of circular frames, wheels, or discs, carrying
on a portion of their circumference movable teeth or chisels. These tools act
as circular saws; they are keyed on the same shaft, say, to the number of five,
more or less, with a space between every two. The engine is worked by pre-
ference with compressed air, which after performing its function in the
cylinder escapes and aids in ventilating the tunnel or other confined work being
excavated. As fast as the saws cut their way, so is the frame advanced, until
they have penetrated to nearly one-half of their diameter; the whole machine
is then drawn back, and the portions of rock or earth between the saw cuts are
readily knocked out by levers, wedges, and other suitable tools, and removed;
the excavator is again advanced and operates as before. A jet of water
directed against the stuff to be acted upon by the saws, will not only
tend to its disaggregation, but will aid in preserving the temper of the cutting
teeth.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Richard Archibald Brooman in the Great Seal Patent Office
on the 8th February 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, RICHARD
ARCHIBALD BROOMAN, of 166, Fleet Street, in the City of London, Patent
Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighth day of August, in the year of our Lord
One thousand eight hundred and sixty, in the twenty-fourth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Richard Archibald Brooman, Her special licence that I, the said Richard
Archibald Brooman, my executors, administrators, and assigns, or such others
as I, the said Richard Archibald Brooman, 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 "AN IMPROVED EXCAVATING MACHINE FOR BORING TUNNELS AND
PERFORMING OTHER EXCAVATING OPERATIONS," (communicated to me from
abroad by Messieurs Hippolyte Amédée Buquet, and Raoul Jacques. Marie
Destrein, of Paris, and Jean Baptiste Valauri, of Turin,) upon the con-

page_text: lition (amongst others) that I, the said Richard Archibald Brooman, my
executors or administrators, by an instrument in writing under my, or
heir, or one of their hands and seals, should particularly describe and
scertain the nature of the said Invention, and in what manner the same
vas 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 Richard Archibald Brooman, 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 Drawings hereunto
annexed, that is to say :-
This machine consists of a strong under carriage or bed mounted on wheels
or rollers, upon which a frame carrying an engine gear work and the ex-
cavating tools hereafter described is free to be moved to and fro. The
excavating tools consist of a series of circular frames, wheels, or discs carrying
on a portion of their circumference movable teeth or chisels. These tools act
as circular saws; they are keyed on the same shaft, say, to the number
of five, more or less, with a space between every two. The engine is worked
by preference with compressed air, which after performing its function in
the cylinder, escapes and aids in ventilating the tunnel or other confined
work being excavated. As fast as the saws cut their way so is the frame
advanced until they have penetrated to nearly one-half of their diameter; the
whole machine is then drawn back, and the portions of rock or earth between
the saw cuts are readily knocked out by levers, wedges, and other suitable
.tools, and removed; the excavator is again advanced and operates as before.
A jet of water directed against the stuff to be acted upon by the saws will
not only tend to its disaggregation, but will aid in preserving the temper
of the
cutting teeth.
•
. The accompanying Drawings illustrate the manner in which my Invention
is carried into effect...
Figure 1, Sheet 1, is a longitudinal section of the excavating machine on
the line A, B, of Figure 2, which is a plan of the same machine; Figure 3,
Sheet 2, is a section on the the line C, D, of the plan Figure 2; Figure 4
shews in detail. the construction of the circular saw..
a is an under carriage or bed supported and running on wheels or rollers a³,
a¹;. b is a frame free to slide to and fro in the bed a. The fore part of the
frame carries a horizontal shaft, on which are: fixed the discs or saws c, c,

page_text: armed with the movable teeth or chisels round a portion of their circumference,
as shewn at Figure 4. The movable teeth or chisels with which.these discs are
fitted, project on each side from the discs, in order that they may cut the
grooves broad enough to prevent the discs coming in contact with the sides of
the grooves; f is the driving cylinder placed at the back of the sliding frame
and fed, by preference with compressed air; the air after being used in the
cylinder is allowed to escape and serves for the ventilation of the tunnel or
other work being excavated. Steam or any other motive agent may be sub-
stituted for air to drive the saws. Motion is transmitted from the crank shaft
to which the piston is connected to the shaft on which the discs are mounted
by means of toothed gear and endless chains, as shewn in Figures 1 and 2:
By turning the pressure screw 9 the frame is pushed slowly forward, and the
bite of the saws upon the rock or other material to be excavated is maintained
until the discs have penetrated to a distance equal to nearly one-half of their
diameter. The whole machine is then drawn back, and the portions of rock
remaining between the saw cuts are knocked out. by wedges, levers, and
'other suitable tools and removed, when the machine is advanced to operate
as before.
In boring tunnels the diameter of the discs must be proportioned to
the work, and for large excavations several series of excavating machines may
be used.
To open a tunnel with the excavating machine two similar machines on the
same level are used, one somewhat in advance of the other, so that when the
first machine has finished cutting its grooves it is drawn back, and the second
one advanced, while the workmen demolish the partitions left between the saw
cuts of the first machine, and also between the courses of the two machines,
and clear away the rubbish. This arrangement is shewn at Figure 5; it will
also be seen by reference to this Figure, that the machine No. 1 has cut
grooves at A, and has been withdrawn as far as the line B, C, to leave a
passage between the points C, D, to allow workmen to enter and clear away
the stuff between the saw cuts at A, and that which formed the partition h,
between the courses of the two machines. In the meanwhile the machine
No. 2 is advanced to act upon the material at E, cutting fresh grooves as
before, and so on.
I do not limit myself to the precise arrangement of the parts herein-before
described, as for instance, the saws may be carried by a franie separate and
distinct from the frame which carries the motive power, and the saws may
be driven by belts from an engine placed in any convenient position.

page_text: And having now described the nature of the said Invention, and in what
manner the same is to be performed, I declare. that I claim, the improved
excavating machine for boring tunnels, and performing other excavating opera-
tions, constructed and acting.substantially in manner herein-before described
and illustrated in the accompanying Drawings.:
R. A. BROOMAŃ. (L.S.)