Improvements in Rock Drills.
Year: 1891

page_text: Improvements in Rock Drills.
I, HORACE GUERNSEY WILLIAMS, of the Town of Lykens, in the County
of Dauphin, and State of Pennsylvania, one of the United States of America,
Rock Contractor, do hereby declare the nature of my invention for "IMPROVE-
MENTS IN ROCK DRILLS" 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 rock drills; and it consists in the novel construction
and combination of the parts by which the drill is actuated, as hereinafter fully
described and claimed.
In the drawings:
Figure 1 is a longitudinal section through the cylinder of the rock drill, taken on
the line in Figure 2.
Figure 2 is a cross-section through the cylinder and one of the air valves, taken
on the line y y in Figure 1.
Figure 3 is a cross-section through the piston rod and distance piece, taken on
the line z z in Figure 1.
B is a long piston working in the cylinder and provided with
a piston rod 6 at one end for connecting it to the drill or other mechanical device
to be worked by the piston.
A is the cylinder.
The piston rod 6 is provided with spiral flat portions 2 which slide back and forth
in a correspondingly shaped hole in a ratchet wheel 3. This ratchet wheel 3
revolves in a chamber 4 in the distance piece 5 which is bolted to the front end of
the cylinder. A stuffing box 6 is secured to the front end of the distance piece,
and that part of the piston rod which passes through the stuffing box is round.
The ratchet wheel is prevented from moving longitudinally by the shoulder 7 of
the distance piece, and the collar 8 arranged between the distance piece and the
cylinder. Washers 9 are arranged on each side of the ratchet wheel to reduce the
friction.
The ratchet wheel 3 is provided with pawls 10 sliding in bosses 11 on the
distance piece. These pawls are adapted to permit the ratchet wheel to revolve
in one direction, and to prevent its return movement. Springs 12 are provided for
pressing the pawls into gear with the teeth of the ratchet wheel, and 13 are caps
screwed into the bosses 11 and adapted to guide the stems of the pawls and to adjust
the pressure of the springs.
When the piston is pushed forward the piston rod turns the ratchet wheel, but
when the piston rod is pushed backward the pawls prevent the ratchet wheel from
turning backward and the flat spiral portions on the piston rod cause it to be
partially revolved thereby giving the drill its necessary rotatory movement at each
in-stroke.
Care india rubber buffers at each end of the cylinder. The cylinder back cover,
and the other parts of the rock drill which are not hereinafter described, and which
are not shown in the drawings, are of ordinary approved construction.
D is the inlet for compressed air or steam, and d is a longitudinal passage
communicating therewith and formed in the side of the cylinder casting.
E are the inlet valves to the cylinder, resting upon the seats E' at the ends of
the passage d, and e are the inlet ports extending from the underside of the inlet
valves and entering the cylinder near its ends.
The passage d is placed in the center, and the ports e are arranged longitudinally
on each side of it in the cylinder casting.
Both the inlet valves and their passages are exactly alike, and each inlet valve
is arranged at that end of the cylinder to which it does not pertain. Thus, the

page_text: valve E at the front end of the cylinder admits the compressed air to the rear end
of the cylinder, and the valve at the rear end admits the compressed air to the
front end of the cylinder. The object of this arrangement is to obtain a large air
space between the underside of each inlet valve and the cylinder. The air is
compressed by the piston into these spaces so that a very great compression in the
ends of the cylinder is avoided.
Fare valves resting upon the seats F1 above the said valves E, the holes
through the seats being a little larger than the valves E so that the valves E
project upward through the said holes and join onto the valves F.
Gare removable caps for closing the valve chambers g, and the said caps are
secured to the valve chambers in any approved manner. The valve stems e' slide
in the guides fin the cylinder and in the caps G, but the valves may be guided in
any other approved manner.
H are small ports which connect the valve chambers g above the valves F with
the middle portion of the cylinder, and g¹ are bosses or pipes in the passage d for
the ports H to pass through. The ports H extend longitudinally past each other
in the cylinder casting.
A circumferential groove 6' is formed in the piston, and this groove has its length
substantially equal to the distance between the ports H.
I are the exhaust ports formed through the side of the cylinder, and provided
with an outlet opening I. Small ports i are also formed through the side of the
cylinder, substantially in line with the ends of the ports H, and open into the said
exhaust ports I.
The action of the engine is as follows: When the parts are in the positions
shown in the drawing and compressed air is allowed to enter the inlet D, the
compressed air raises the valves E and F at the front end of the cylinder, because
the diameter of the hole through the valve seat F' is greater than the diameter of
the valve E, and because the chamber 9 above the valve F is in communication
with the atmosphere through the ports H and i, the groove b¹ and the exhaust
port I.
The compressed air passes through the valve E, down the port e into the rear
end of the cylinder, and propels the piston in the direction of the arrow in Figure 1.
The forward motion of the piston closes the exhaust port I at the front end of the
cylinder, and also closes the small port H at the rear part of the cylinder. The
expansion of the compressed air in the cylinder, together with the momentum of
the reciprocating parts, carries the piston onward until the exhaust port I at the
rear end of the cylinder is uncovered, the air being compressed in the front end of
the cylinder and in the port e communicating with it during the latter part of the
stroke of the piston. The forward motion of the piston also places the chamber g
above the valve F, at the rear end of the cylinder, in communication with the
exhaust port I, at the front end of the cylinder, directly after it closes the small
port H at the rear end of the cylinder. The piston however continues its forward
stroke after uncovering the exhaust port at the rear end of the cylinder, because it
moves with a very high velocity, and because it takes a certain space of time for
the compressed air to raise the valves E and F and to rush from the passage d
through the valve E and down the port e into the front end of the cylinder..
Directly the piston arrives at the end of its forward stroke it is propelled rear-
wardly by the air compressed by it in the front end of the cylinder and in the
port e leading into that end, and by the compressed air which rushes in through
the valve E.
The piston returns to the rear end of the cylinder, and will continue to
reciprocate in the cylinder as long as compressed air is supplied.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that" what 'I'
claim is:
.:.... chai bil=
1. The combination, with a cylinder provided with inlet ports, of a long piston

page_text: working in the cylinder, and separate lift valves resting upon seats at each end of
the cylinder and normally closing the said inlet ports and adapted to open
automatically when the pressure behind them is released by the said piston,
substantially as set forth.
2. The combination, with a cylinder provided with inlet ports and the small
ports H, of a long sliding piston provided with a groove, and separate lift valves
resting upon seats at each end of the cylinder and normally closing the said inlet
ports and adapted to open automatically when the pressure behind them is allowed
to escape through the said small ports and groove, substantially as set forth.
4. The combination, with a cylinder provided with the inlet passage d, the valve
seats E and F, the inlet port e, the valve chamber above the valve seat F',
and the small port H between the said chamber and the cylinder; of the two
valves connected together and normally resting on the said seats, and a long piston
provided with a groove adapted to uncover the said port H, thereby relieving the
pressure in the said chamber and permitting the valves to open automatically,
substantially as and for the purpose set forth.
5. The combination, with a cylinder provided with an inlet port and an exhaust
port, of a long piston adapted to cover and uncover the said exhaust port and
provided with a groove, a valve normally closing the said inlet port, a small port
opening into the cylinder and adapted to relieve the pressure behind the said
valve and permit the valve to open automatically when the small port is uncovered
by the said groove, and a second small port extending from the cylinder into the
said exhaust port and also adapted to be uncovered by the said groove, substan-
tially as set forth.
6. The combination, with the cylinder, and the long grooved piston sliding
therein, of separate lift valves resting upon seats at those ends of the cylinder to
which they do not pertain, the said cylinder being provided with ports extending
longitudinally past each other and connecting the said valves with the ends of the
cylinder to which they do pertain, and having small ports also extending past each
other and adapted to relieve the pressure behind the said valves and to permit
them to open automatically when the said small ports are uncovered by the piston
in the cylinder, substantially as set forth.
7. The combination, with the piston rod provided with spiral flat portions, of a
ratchet wheel mounted on the said portions, the distance piece inclosing the
piston rod and ratchet wheel and provided with a stuffing-box at its front end, and
the spring-actuated pawls adapted to engage with the ratchet wheel, whereby the
piston rod may be partially revolved at each in-stroke, substantially as set forth.
Dated this 6th day of October 1891.
WHEATLEY & MACKENZIE,
Agents for Applicant.