IMPROVEMENTS IN ROCK DRILL MACHINES
Year: 1885

page_text: I RICHARD STEPHENS of Wheal Crofty Works, Carn Brea, Illogan in the county
of Cornwall, Mining Engineer do hereby declare the nature of the said invention
for "IMPROVEMENTS IN ROCK DRILL MACHINES" to be as follows:-
This invention relates to improvements in rock drill machines the improvements
consisting in the employment of a lengthened cam or tappet of a particular form
which enables the machine to dispense with lengthy ports for the receiving and
disposing of air or other motive power thus saving travelling time to the said air
and enabling the machine to run faster the said tappet or can being actuated
gently and quickly by a ball on the piston; in placing the valves at or near the
end of the receiver so as to shorten the length of passage through which the air or
motive power is supplied to the machine thereby saving time in the supply and
exhaust and allowing of quicker and more direct and therefore more effective
feeding of the machine; and as the valves are made single valves and placed so
that they move freely either at the ends or sides of the said tappet or cam they
further assist in the economizing of air and allow of the shortened ports being used
and further the valves being placed at the ends of the cylinder or receiver enables
me to use the said valves and tappet in the manner hereinafter described.
The improved machine is constructed of a cylinder and receiver or valve chest,
the one placed at the said of the other and communicating by ports or channels
as hereinafter described and a piston connected by a rod on which rod is placed
a ball.
In the receiver or valve chest is placed a tappet or cam with long arms into or
on the ends of which cam or tappet or into or on the sides of which is cut or
placed niches or projections or other appliances for connecting the valves with the
said cam or tappet. At each end of the valve chest and receiver are ports or air
channels for the purpose of conducting the air to the cylinder and actuating
the piston and also for the purpose of receiving the exhaust air from the said
cylinder.
In the accompanying drawing A A, is the piston; a, a, a, is the ball on the said
piston; B B is the cylinder; C, C, the valve chest and receiver; c, c, the tappet
or cam; D, D, the valves fixed in the ends of the said tappet or cam; E E the
ports or air channels for the purpose of conducting the air or other motive fluid to

page_text: the cylinder and piston; F, F, the exhaust ports for the purpose of receiving the
waste air from this cylinder, after the same air has been utilised; G, is the aperture
for receiving motive power.
The mode of working my machine is as follows:-
Compressed air, steam, gas or other motive fluid is introduced in the machine
through the aperture G, the motive fluid then spreads itself through the receiver or
valve chest C, C, and one of the ports E, being open the motive fluid rushes
through the same port into the cylinder B B; the effect of this is to force the
piston AA backwards or forwards towards the opposite end of the machine to that
from which the motive fluid entered in the said passage of the cylinder the
ball a, a, will slide along the unequal surface or side of the tappet or cam and so
raise the end of the tappet to which is affixed the valve opposite the valve first
moved. This will have the effect of admitting the motive fluid from the end of
the receiver through the port or channel at that end and so driving the piston
back to its former position which however in its passage back will again by means
of the said ball and tappet or cam actuate the opposite valve and will thus again
be returned. On the return of the piston the air that has been used will by the
raising of the tappet be all allowed to escape from the cylinder into the port E E
and thence through the exhaust ports F, F out of the machine.
G. F. REDFERN,
4, South Street, Finsbury, London,
Agent for the Applicant.

page_text: I RICHARD STEPHENS, of Wheal Crofty Works, Carn Bred, Illogan in the county
of Cornwall, Mining 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:-
This invention relates to improvements in rock drill machines the said improve-
ments consisting in the employment of a lengthened cam or tappet of a particular
form which enables the machine to dispense with lengthy ports for the receiving
and disposing of air or other motive power, thus saving travelling time to the said
air and enabling the machine to run faster, the said tappet or cam being actuated
gently and quickly by a ball or spherical enlargement on the piston; in placing
the valves at or near the end of the receiver so as to shorten the length of the
passages or ports through which the air or motive power is supplied to the machine
thereby saving time in the supply and exhaust and allowing of quicker and more
direct and therefore more effective feeding of the machine; and as the valves are
made single valves and placed so that they move freely either at the ends or sides
of the said tappet or cam they further assist in the economizing of air and allow of
the shortened ports being used and further the valves being placed at the ends of
the cylinder or receiver enables me to use the said valves and tappet in the
manner hereinafter described.
The improved machine is constructed of a cylinder and receiver or valve chest
the one placed at the side of the other and communicating by ports or channels as
hereinafter described and a piston the two ends of which are connected by a rod
on which rod is formed a ball or spherical enlargement.
In the receiver or valve chest is placed a tappet or cam with long arins into or
on the ends of which cam or tappet or into or on the sides of which are cut or
placed niches or projections or other appliances for connecting the valves (which
have corresponding projections) with the said cam or tappet. At each end of the
valve chest and receiver are the ports or air channels for the purpose of conducting
the air to the cylinder and actuating the piston and also for the purpose of
receiving the exhaust air from the said cylinder.
In order to enable my invention to be fully understood I will proceed to describe
the same by reference to the accompanying drawing in which figure 1, represents a
side elevation of a rock drilling machine constructed according to my invention the
valve chest cover being removed and figure 2 represents a central horizontal section
of the same. Similar letters of reference refer to similar parts in both the figures
of the drawing.
A, A', represent the piston and A2, the rod connecting the ends of the same,
a, is the ball or spherical enlargement formed on the piston rod A²; B, represents
the cylinder on the side of which is formed the valve chest and receiver C; c, is
the tappet or cam and d, are the niches formed in the ends of the same, c, are the
projections on the valves D, D¹, which projections correspond and engage with the
niches d; E, E, are the ports or air channels at each end of the valve chest and
receiver C, for the purpose of conducting the air or other motive fluid to the

page_text: cylinder B, and piston A, A¹; F, F, are the exhaust ports for the purpose of
receiving the waste air from the cylinder B, after the same air has been utilised.
In the cover f, of the valve chest is formed an aperture G, for receiving the air or
other motive power.
The mode of working the improved machine is as follows:-
Compressed air, steam, gas or other motive fluid being introduced into the
machine through the aperture G, the motive fluid will spread itself through the
receiver or valve chest C, and one of the ports E, being open as shewn at the left
hand side of figure 2, the motive fluid will rush through the said port into the
cylinder B, and act upon the end A, of the piston; the effect of this is to force
the piston A, A', towards the opposite end of the cylinder at the same time the
ball a, will slide along the unequal surface or side g, (shewn in figure 2) of the
tappet or cam c, and so raise the opposite end of the tappet to which is affixed
the valve D. This will have the effect of admitting the motive fluid from the end
of the receiver through the port or channel E', and which by acting on the end A¹,
of the piston will drive the piston A, A¹, back to its former position.
The said backward movement however will again by means of the said ball a,
and tappet or cam c, actuate the opposite valve and the piston A, A', will thus
again be returned and so on. At each stroke of the piston A, A1, the air that has
.been used to effect its previous stroke will by the raising of one end of the tappet
and consequently the valve to which it is attached be allowed to escape from the
end of the cylinder in which it is contained into the port E or E', at the said end,
and thence through the exhaust port F or F', out of the machine.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
1. In a rock drill machine a lengthened cam or tappet of the form herein
described and shewn arranged to be operated by a ball or spherical enlargement on
the piston substantially in the manner and for the purposes hereinbefore described
and represented in the accompanying drawing.
2. In a rock drill machine arranging the valves at or near the end of the
receiver so as to shorten the length of passage through which the air or motive
power is supplied to the machine substantially as and for the purposes hereinbefore
described and represented in the accompanying drawing.
3. In a rock drill the employment of single valves arranged to move freely
either at the ends or sides of the herein described tappet or cam thereby assisting
in the economizing of air and allowing of the shortened ports being used sub-
stantially as herein before described and represented in the accompanying drawing.
4. The improved rock drill machine hereinbefore described and represented in
the accompanying drawing.
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