IMPROVEMENTS IN MACHINERY OR APPARATUS FOR DRIVING HOLES OR DRIFTWAYS IN Rocks
Year: 1871

page_text: PROVISIONAL SPECIFICATION left by Emile Watteeu at the Office
of the Commissioners of Patents, with his Petition, on the 8th
November 1871.-A communication from abroad by Joseph
Francois and Guillaume Dubois, both of Liége, in the Kingdom of
Belgium.
.I, EMILE WATTEEU, of The Royal Exchange, Middlesboro'-on-Tees,
in the County of York, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN MACHINERY OR APPARATUS FOR DRIVING HOLES
OR DRIFTWAYS IN Rocks," to be as follows:-
This Invention has reference to an improved construction of machinery
or apparatus operated by compressed air, steam, or other fluid under
pressure for driving holes or driftways in rocks, of which the principal
parts are shown in the longitudinal section of the machine on the
accompanying Drawing.
The Invention consists mainly in peculiar and novel devices for
operating the slide valve of the machine, and for effecting the rotation of
the cutting tool or chisel.

page_text: On the Drawing B is a cylinder carried by a suitable framing, in which
cylinder works the piston C, to the end of the piston rod C' of which is
attached the cutting tool or chisel. The piston O has the requisite
reciprocating motion imparted to it by the admission of compressed air,
steam, or other fluid under pressure alternately through the passages or
ports Z, Z', the slide valve N being made to control such admission by
the following means:-Upon the piston rod O' is formed or fixed a
circular tappet D, which at the end of each back stroke of the piston rod
is caused to come in contact with the pedal or trigger E turning on a
pin F. This trigger in being actuated by the tappet D strikes against
the stem G¹ of a valve G, closing. an escape aperture in the slide valvo
box K, the valve G being kept closed by a spring H when not actuated
by the trigger. The slide valve N is connected by two rods M, M', to
two pistons I, L, working in cylindrical parts K', K', of the slide valve
box. The piston L is smaller in diameter than I; on its inner face it is
acted upon by the pressure of the air or steam in the valve box K, while
on its outer face it is only acted upon by the atmospheric pressure, the
cylindrical hole K' being open at the outer end. The piston I is acted
upon on both faces by the pressure of the air or steam in the valve box,
the rod M' being for this purpose formed with a hollow passage P, into
which opens a small lateral hole O, so that the steam or air can pass
through the rod M¹ to the space K' on the outer side of the piston.
From this arrangement it will be seen that if the valve G is closed, the
pressure upon the piston I being in equilibrio, while the pressure on the
inner face of the piston L is in excess of the atmospheric pressure on its
outer face, the slide valve will be moved over so as to uncover the port Z',
and thus admit steam or air to the front of the piston O for effecting the
back stroke of the piston rod and chisel. In thus moving back the
tappet D is brought in contact with the trigger E, whereby the valve G
will be forced open. The air or steam will now escape from the space.K'
quicker than it can flow through the small opening O, and the pressure
of the air or steam upon the inner face of the piston I in overbalancing
the pressure upon the smaller area of the piston L, will cause the slide
valve to move over so as to open the port Z for effecting the forward or
working stroke of the piston C and cutting tool. As soon as the tappet
D has moved forward sufficiently to release the trigger E the spring H
will close the valve G, and an equilibrium of pressure on the piston I
being thus re-established the slide valve will be again moved over as first

page_text: described for producing the next back stroke of the piston O. U, U, are
fixed stops for limiting the motion of the slide valve N.
For partially rotating the cutting chisel at each stroke, the piston rod
C¹ (the front part of which is formed of a triangular or polygonal
section) slides through a bush capable of rotating in the front part of
the framing, and carrying a ratchet wheel, in gear with which is a pawl
carried by an arm on the end of the rod c; this rod is of a square section,
and passes through cylindrical bushes V₁ carried by a bracket V, and also
through a sleeve S having two opposite lateral tappets which are raised
alternately, so as to impart the requisite rocking motion to the rod c for
actuating the pawl and ratchet wheel by two pistons working in
cylindrical recesses on each side of the slide valve box, into which
cylindrical recesses steam or air under pressure is admitted alternately
through the hole T, T', in the ports Z, Z', of the cylinder B so as to raise
the said pistons.