IMPROVEMENTS IN DRILL HEADS FOR ROCK BURING AND TUNNELLING
Year: 1873

page_text: LETTERS PATENT to John Macvicar Rigby, of Manchester, in tho
County of Lancaster, Engineer, for the Invention of "IMPROVEMENTS
IN DRILL HEADS FOR ROCK BURING AND TUNNELLING."
Scaled the 9th September 1875, and dated the 11th March 1873.
PROVISIONAL SPECIFICATION left by the said John Macvicar Rigby
at the Office of the Commissioners of Patents, with his Petition,
on the 11th March 1873.
I, JOHN MACVICAR RIGBY, of Manchester, in the County of Lancaster,
Engineer, do hereby declare the nature of the said Invention for "Ix-
PROVEMENTS IN DRILL HEADS FOR ROCK BORING AND TUNNELLING,” to be as
follows:-
My improvements relate to thoso machines for boring and tunnelling
rocks which are known as diamond borers, or to others of a similar
character, and consist in a method of actuating the boring bar and nut
for the purpose of rotating, advancing, and withdrawing the tool, which
objects I propose to effect with one driving wheel.
For this purpose a
disc is placed upon the main shaft, provided with two sets of teeth
gearing into two wheels mounted loosely on collars surrounding tho

page_text: boring bar, but capable of being connected thereto by clutch boxes,
One of these collars drives the boring bar by means of a groove and
feather, and the other is formed as a nut, taking into the screw of the
boring bar. The wheel connected to the nut has a different number of
teeth to that which drives the boring bar, and will therefore rotate with
a different velocity, consequently advancing the feed.
When it is desired to withdraw the boring bar, one of the clutches
which locks the toothed wheel to its collar is disconnected, and the
boring bar still continuing to rotate is withdrawn.
The cutting tool is of any usual construction, and may be driven by
friction as now practised.
SPECIFICATION in pursuance of the conditions of the Letters Patent
filed by the said John Macvicar Rigby in the Great Scal Patent
Office on the 11th September 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
MACVICAR RIGBY, of Manchester, in the County of Lancaster, Engineer,:
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eleventh day of March, Ono thousand
eight hundred and seventy-three, in the thirty-sixth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me,
the said John Macvicar Rigby, Her special license that I, the said John
Macvicar Rigby, my executors administrators, and assigns, or such others
as I, the said John Macvicar Rigby, my executors, administrators, and
assigns, should at any time agree with, and no others, from time to time
and at all times thercafter during the term therein expressed, should
and lawfully might make, use, excrcise, and vend, within the United
Kingdom of Great Britain and Ireland, the Channel Islands, and Isle
of Man, an Invention for "IMPROVEMENTS IN DRILL HEADS FOR ROCK BORING
AND TUNNELLING," upon the condition, (amongst others), that I, the said
John Macvicar Rigby, by an instrument in writing under my hand and
scal, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and cause

page_text: 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 John Macvicar Rigby, do hereby
declare the nature of my said Invention, and in what manner the samo
is to be performed, to be particularly described and ascertained in and
by the following statement (and accompanying Drawings) that is to
say:
My improvements relate to those machines for boring and tunnelling
rocks which are known as diamond borers, or to others of a similar.
character, and consists in a method of actuating the boring bar and nut
for the purposes of rotating, alvancing, and withdrawing the toọ), which
objects I effect from ono main driving wheel.
In the accompanying Drawings Fig. 1 represents the drill head in
longitudinal section; and Fig. 2 is a longitudinal view looking under
Fig. 1.
At a is the usual frame, which carries the drill head, capable of being
turned into any required position and of being retained thero by nuts &
in the ordinary manner; at c is the tube through which the boring bar
(shewn by the red lines) passes, the said tube being supported at d by the
frame a; and ate is the nut, also supported by the frame a, and by
which tho bar is caused to move to and fro, the said bar being threaded
as usual and provided with a groove, in which is situate a key, formed
upon the interior of the tube c. The main driving wheel is shown at ƒ,
mounted on the shaft g, and provided according to my Invention with
two sets of teeth h, h*, the arrangement being equivalent to two wheels
fast with each, and these teeth take respectively into wheels i, k, mounted
loosely on the tube c, the one being so arranged as to revolve at a
different rate rate to the other . Atlis a clutch, mounted on the tubo o
by means of a feather, and capable of being put into gear with a clutch
box m formed on the wheel 7, the movement of the said clutch being
effected by a lever n, which carries a nut o, situato within a circular
slot P. and on this nut being tightened the said lover is retained in a
desired position. The wheel & is provided with a collar 9, which carries
a friction coner, extending into a ring 8, mounted loose upon the tube c,
and provided with an annular recess, in which is situated a friction
hoopt, capable of being tightened or loosened in the said, recess by

page_text: means of a nut n, but between the flanges of the hoop is a pin »,
extending from a boss w formed on the nut e. The friction cone 1 is
mounted on the collar q with a feather, and is provided with a recess x,
within which are pins y, projecting from levers z, mounted on a shaft 1,
which carries a worm wheel 2, in gear with a worm 3, carried by a shaft 5
on which there is a pulley handle 4, by turning which the said pins y
may cause the friction coner to bind with the rings or be free from it.
At 6 is a block of wood fixed on a plate, which is hinged at 7, and the
said block is capable of being pressed against the boss of the nut e to
act as a break by means of a screw 8; and at 9 is a similar block, 1
which by means of a screw 10 may be caused to act as a break the
upon
tube c.
According to the position of the parts shewn in the Drawing, the
boring bar is being withdrawn, that is, moved in the direction of the
arrow. To accomplish this the block 6 has been loosened, the friction 1
coner placed in gear with the rings by the pulley handle 4, and the
block 9 tightened by the screw 10 upon the tube c, the clutch box l, m,
being out of gear. The shaft q being driven will cause the wheel i
simply to revolve loosely on the tube c, effecting no result, and the wheel
constituted by the teeth & will also revolve loosely on the same tube, but 2
as it is fast with the cone r, which is in gear with the ring 8, it will
cause that part to revolve, and the friction hoop t will carry round the
nute, and thus the withdrawal of the bar will be effected. If now it is
desired to cause the bar to move quickly to its boring position, the
friction coner is removed from the ring s, so that the nut e may remain 2
stationary, it being held by the brake 6, and the clutch l, m, is put into
gear, thereby locking the wheel i to the tube c, which being thus caused
to be fast therewith, will revolve and turn the boring bar in the nut e,
thereby running it down to its boring position, after which it is necessary,
as is well known, that the said bar shall advance slower. To effect this 3
the break 6 is removed and the friction concr put into gear, and thus
the boring bar and nut e will both be caused to revolve. If these
motions took place at equal rates it is evident that no advance of the bar
would take place, but the wheels h, h*, i, k, are so arranged that the
nut e by running shall by its motion neutralize a sufficient portion of
the traverse which was used to run the bar down.
The relative speeds of the nut and bar may be varied for different rates
the haala

page_text: Having thus described tlio nature of my said Invention, and the
manner in which the same is to be performed, I desiro it to bo
understood that I claim as secured to me under the abovo in part
recited Letters Patent, the arrangement of drill head, substantially as
shown and described, the main features being that the parts which effect
the several motions of the boring bar are all placed upon the tube which
carries it, and aro all actuated by one driving wheel.
'
In witness whereof, I, the said John Macvicar Rigby, have here.
unto set my hand and scal, this Tenth day of September, in
the year of our Lord One thousand eight hundred and seventy-
throo