IMPROVEMENTS IN ROCK OR STONE DRILLING APPARATUS
Year: 1873

page_text: PROVISIONAL SPECIFICATION left by Frederick Edward Blackett
Beaumont at the Office of the Commissioners of Patents, with his
Petition, on the 28th May 1873.
I, FREDERICK EDWARD BLACKETT BEAUMONT, of No. 2, Westminster
Chambers, Victoria Street, in the City of Westminster, a Major in the
Royal Engineers, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN ROCK OR STONE DRILLING APPARATUS," to be as
follows:-
My Invention relates to that description of rock or stone drilling
apparatus wherein a boring tool is made to operate by percussive action
by means of compressed air or other elastic fluid operating in a cylinder,
so as to impart a reciprocating motion to a piston, to the rod of which
the boring tool is attached. In such apparatus as heretofore employed
when a number of such rock drills are used, the cylinder of each rock
drill has been provided with its own slide or other valve for regulating
the passage of the elastic fluid to and from the cylinder, and thus more
or less complex valve gear is necessarily brought into direct connection

page_text: with the boring cylinder, and is consequently liable to injury from the
very nature of the work done.
Now according to my present Invention I dispense with the separate
valves and gear to each drill cylinder, and I provide one single slide
valve for operating a group of such drills, such slide valve being entirely
separate from the drill cylinders and by preference situated at some
distance therefrom. This slide valve is worked by an independent
engine, and the ports of the drill cylinders are connected by flexible or
jointed pipes to the inlet and exhaust ports of the slide valve casing, so
that by the motion of the slide valve the elastic fluid is caused to pass
simultaneously to the one end of all the drill cylinders while the elastic
fluid passes simultaneously from the other ends of all the drill cylinders
to the exhaust port of the slide valve.
By preference I arrange such drill cylinders on the vertical standards
or uprights of a framing constructed as described in the Specification to
Letters Patent granted to myself and C. J. Appleby, on the 7th
February 1872, No. 392, or as described in the Specification to other
Letters Patent granted to myself and C. J. Appleby, on the 21st of May
1868, No. 1682, the drill cylinders being carried by the adjustable face
plates of such standards.
The partial rotation of the drills or borers at each stroke is effected by
a small cylinder supplied with air from the supply pipes to the drill
cylinders and having a piston the rod of which actuates a ratchet in
gear with a ratchet wheel on a rod passing from the drill piston through
the back end of the drill cylinder.
For effecting the advance of the drill cylinder as the boring proceeds,
the drill cylinder (which slides in guides on the before mentioned face
plates on the uprights) is provided with a bracket carrying a ratchet
wheel fitting with a female screw on to a screw spindle carried by the
face plate. The before mentioned rod passing from the drill piston
through the back of the drill cylinder is provided with a curved incline
or cone (depending on the degree and quality of motion required), which
on the back stroke of the drill piston is made to act on a ratchet in gear
with the said ratchet wheel carried by the drill cylinder, so that at each
back stroke of the piston the ratchet wheel is turned slightly on the
screw spindle and thus the advance of the drill cylinder is effected. The

page_text: screw spindle is provided with a hand wheel so that it can be rotated by
hand for drawing the drill cylinder back after a hole has been bored, the
rotation of the screw spindle while the drill cylinder is at work being
prevented by a catch or other suitable known contrivance.