Improvements in Rock Drills and the like.
Year: 1889

page_text: Date of Application, 29th Apr., 1889
Complete Specification Left, 28th Jan., 1890-Accepted, 1st Mar., 1890
PROVISIONAI. SPECIFICATION.
Improvements in Rock Drills and the like.
ARTHUR CHAPMAN Vulcan Iron Works Rhodeswell Road Limehouse London E.
Engineer do hereby declare the nature of this invention to be as follows:-
1st. An improved method of rotating the working rod, or spindle, (holding the
drill) a portion of a revolution between each blow, consisting of a ratchet wheel
fixed upon the working rod, and having teeth at an incline with the axis, formed upon
its periphery, engaging in a slide fitting these teeth, & working in an angular slot,
or groove in the cylinder, or frame of drills, worked by steam, or air, or by hand
power.
2nd. An improved method of actuating the automatic feed of Rock Drills worked
by steam or other power, or by hand power consisting of an elongation of the working
rod, or spindle through the top cover, or frame, and having a cone formed thereon,
which as the Drill, (secured into the other end of the rod) advances into the rock or
other material being bored strikes upon a lever pivotted at one end, and carrying the
pawl which engages the feed ratchet at the other end, giving advance motion to the
Drill by the movement of the feed ratchet nut.
3rd. The construction in a hand power Rock Drill of the mechanism for imparting
the reciprocating motion to the working rod consisting of a loose collar between
2 fixed collars upon the working rod, and having on each side a square extension
working freely in a slot or groove formed in the cylinder or frame, and extending
beyond a sufficient distance to engage upon cams formed of the proper shape for
lifting gradually, and letting go suddenly the extensions of the collar so engaged upon
them. This collar with its square extensions being so formed as to be reversible, and
adjustable enabling each corner of the square to be used as a new wearing surface.
4th. The combination of the above or any one of them in a Rock Drill or similar
instrument.
COMPLETE SPECIFICATION.
Improvements in Rock Drills and the like.
I ARTHUR CHAPMAN, Vulcan Iron Works, Spencer Street, Rhodeswell Road, Lime-
house, in the County of Middlesex, 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 :-
My Invention relates chiefly to Rock Drills worked by manual power, but portions
of it may be used in Rock Drills worked by steam, compressed air, or other motive
power, and having for its object an improved method of imparting a reciprocating
motion to the working rod containing the Drill bit, also an improved mole of actuating
the automatic feed of Rock Drills, and an improved method of rotating the working
or piston rod (containing the Drill bit) a portion of a revolution between each
blow.
In the accompanying Drawings
Fig. 1 is an elevation shewing the general arrangement, and the wheels and handles
for working by manual power.
Fig. 2 is a sectional elevation, shewing the internal arrangement.
Fig. 3 is a plan of top of frame on cylinder cover.
Fig. 4 is an elevation of part of the working rod, shewing fixed collars, cross bar,
ratchet wheel and cone.

page_text: Fig. 6 is an elevation of the working cams.
A is the working (or piston) rod, carrying the Drill bit.
B is the loose collar with a square extension on each side (called the cross bar).
C. C. are the working cains.
Dis the rotating ratchet wheel, secured upon the working (or piston) rod, and
having teeth at an angle with its axis.
E is the slide or catch engaging in the teeth of rotating ratchet.
F is a cone on the top end of the working (or piston) rod, for actuating the
automatic feed.
G is the feed lever and pawl.
H is the feed ratchet nut.
I is a powerful volute spring held between the collar on working rod and cylinder
cover or frame top.
The operation of my Improved Rock Drill is as follows.
On turning the rotating shaft, having the cams C. C. secured thereon, the projections
of the cams engage under the ends of the cross bar B. B. (this cross bar being loose
upon the working rod A and held between two fixed collars on same). As the cams
revolve they lift the cross bar and working rod compressing the volute spring I, at the
top of the stroke the cams suddenly release the cross bar, and the recoil of the spring I
causes the working rod to descend rapidly and forcibly striking a heavy blow.
As the working rod A ascends as before mentioned, the inclined teeth of the ratchet
wheel D engage in the slide or catch E causing a partial rotation of the working
rod A and this being repeated at every stroke gives a gradual rotation of the
Drill bit.
The automatic feed of the Drill so as to advance the drill bit in exact proportion to
the work done is constructed and actuated as follows.
At the top of the working (or riston) rod A a cone F is formed and a lever G
hollowed to fit the working rod A. is pivoted on the top of frame or cover, and has at
its free end a pawl which engages in the teeth of the feed ratchet nut H, and a spiral
or other spring which holds it against the working rod A. The down stroke is regulated
in extent by the depth the drill bit has descended into the material being operated
upon. When it has descended sufficiently to allow the cone F to go below the top of
the cover or frame, as shewn in Fig. 2, the lever G is drawn by the spring over the
cone F, and on the up-stroke the cone F thrusts out the lever G and pawl, giving a
partial rotation to the feed ratchet nut H, repeating this as often as the cone F descends
far enough for the lever G to be drawn over it.
The cross bar B is so formed that by reversing it, fresh wearing faces are presented
to the work until all the four faces have been used.
The cams C. C. are shewn with three projections, but may be made with any
convenient number.
This drill may be fixed on a tripod, frame, stand or column in the usual manner.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed declare that what I
claim is
1st. In Rock Drills worked by manual power, the cross bar with projecting ends
for engaging the cams, such cross bar being loose upon the working rod, and held
between two fixed collars and formed with duplicate wearing surfaces, substantially in
the manner and for the purpose described.
2nd. In Rock Drills worked by manual power, the operating cams of the form
shewn and described.
3rd. In Rock Drills worked by steam compressed air, or manual power, the ratchet
wheel fixed on the working (or piston) rod, having on its periphery teeth on an angle
with its axis, and a slide or catch fitting these teeth, and causing the rotation of the
working (or piston) rod, by its reciprocating motion substantially in the manner and
for the purpose described.

page_text: 4th. In Rock Drills worked by steam, air, or manual power
An elongation of the working (or piston) rod upwards, having a cone or angle
formed thereon, acting upon the feed lever (or rod) and pawl, substantially in the
manner and for the purpose described.
5th. The combination of the various features hereinbefore described or any of them
in any Rock Drill.
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