Improvements in Machines for Boring Rocks or other Hard Substances.
Year: 1898

page_text: Date of Application, 10th Oct., 1898-Accepted, 12th Nov., 1898
COMPLETE SPECIFICATION.
Improvements in Machines for Boring Rocks or other Hard
Substances.
We, GRANVILLE SHARP ULLATHORNE, of 63, Queen Victoria Street, in the City
of London, Civil Engineer, and HERBERT PERKINS VACHER, of 63, Queen
Victoria Street, in the City of London, Civil Engineer, do hereby declare the
nature of this invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement:-
The invention relates to and has for its objects, improvements in machines
worked by steam, compressed air, or other motive fluid, for boring rock or other
hard substance-in which a jumper or drill attached to the piston rod is carried
to and fro by the action of a piston working in a cylinder-whereby such
machines may be simpler in construction than other machines of the kind.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 represents a longitudinal section of the machine.
Fig. 2 represents a transverse section through the centre of the inlet chest..
The machine is so constructed that holes or ports in the cylinder and pas-
sages in the piston regulate the distribution and escape of the motive fluid with-
out any slide or other distributing valve usual in machines of this kind.
The piston bis formed in one piece solid with the piston rod d, or built up to
form one piece. The piston has two annular recesses r, s, in it, so that there
may be said to be three pistons in one. Passages f are made through the pis-
ton b from the front annular recess to the space a, in the front end of the
cylinder a, and similarly passages g are made through the piston b from the
back annular recess s to the space a₂ in the back end of the cylinder. The
cylinder a is provided with an inlet chest c and is furnished with back and front
covers. Two sets of holes or ports o p are made from the inlet chest c into the
cylinder a, at some distance apart longitudinally that is to say in the direction
of the length of the cylinder. Through these holes or ports o, p, the motive
fluid is admitted from the inlet chest of the cylinder. The front set of holes or
ports o serve to take the motive fluid to the space a, in the front end of the
cylinder, and the back set of holes p to take the motive fluid to the space a
in the back end of the cylinder as hereinafter described.
The action of the machine is as follows:―
The motive fluid is admitted to the inlet chest c, and when the piston is at
the back end of the stroke as shewn in Fig. 1, the motive fluid is prevented
from entering the cylinder through the front set of holes or ports o, by reason
of a part of the piston 6 covering these holes o, but the motive fluid freely
enters the cylinder through the back set of holes or ports p by reason of the
back recess s of the piston being over these holes 7, and thence the. motive fluid
travels through the passages g to the back end of the cylinder ; at the same
time the front recess r of the piston is over the exhaust holes, allowing the
motive fluid from the front end a₁, of the cylinder to travel through the pas-
sages and so escape through the exhaust holes .r. The result is, the piston b
CD '

page_text: is forced forward in the cylinder by the motive fluid, and is carried by its
momentum to a position at the front end of the cylinder.
The space a, in the front end of the cylinder is then in communication with
the motive fluid through the front holes o, and passages f from the front recess r,
while the space a, at the back end of the cylinder is in communication with the
exhaust holes through the passages g to the back recess s, resulting in the
piston being forced back by the motive fluid to its position at the back end of
the cylinder. Thus the piston is reciprocated.
The partial rotation of the piston, piston rod, and jumper may be effected
automatically by means of a nut n in the piston working on a twisted or rifled
bar similarly as in some other machines of the kind, or by means of other
suitable device.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, we declare that
what we claim is:-
In machines of the kind specified; -The arrangement of holes or ports for the
inlet of the motive fluid direct into the cylinder without any intervening slide
valve, or other distributing valve, combined with the arrangement of two annular
recesses in the piston, with passages through the piston, connecting the front
annular recess with the space in the front end of the cylinder, and the back
annular recess with the space in the back end of the cylinder, and of exhaust
holes direct from the cylinder, the whole forming a means of distribution and
escape of the motive fluid to cause the piston to be actuated to and fro, substan-
tially as described and set forth in the accompanying drawings.
Dated this First day of October 1898.
G. S. ULLATHORNE,
H. P. VACHER.