Improvements in Rock Boring and Drilling Machines.
Year: 1888

page_text: Complete Specification Left, 12th Oct., 1889-Accepted, 16th Nov., 1889
PROVISIONAL SPECIFICATION.
Improvements in Rock Boring and Drilling Machines.
We JOHN EVAN POWELL, ROBERT JONES POWELL and WILLIAM WHITAKER all of
Cambrian Iron Works, Wrexham, in the county of Denbigh, Engineers, do hereby
declare the nature of this invention to be as follows:-
Our invention relates to rock boring and drilling machines, and has for its object
to simplify the construction of such machines and to render the same more efficient
in operation than heretofore; and to these ends it comprises the improvements herein
after described.
According to our said invention a piston-rod is provided with two pistons, each of
which works in connection with an independent set of ports formed in the cylinder
of the drill; these pistons are of considerable length and provided with metallic
packing, so that a large wearing surface is formed.
One of the said pistons has passing through it a twist-bar, by means of which the
piston-rod with the tool is gradually rotated. This twist-bar carries at its outer end
u ratchet wheel, in connection with which are double ended pawls which allow of the
rotation of the ratchet wheel in one direction and prevent any movement in the
opposite direction.
The two sets of ports are located within a dove-tailed slide which is formed integral
with the cylinder and slides in the cradle, so that they are protected from accidental
damage more effectually than if placed on any other part of the cylinder.
In order to prevent any escape of air between the cylinder and the piston-rod, the
stuffing box through which the piston-rod passes is packed with metallic rings
behind which are placed india rubber rings, the latter serving to tightly compress
the metallic rings, upon the rod and thereby ensure an uniform tightness.
We also employ a clip of novel construction, this clip is formed without ears or
lugs and is provided with only a single bolt and nut, by means of which the stretcher
bar and cradle can be locked at one operation.
Date the 14th JD 1000
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in Rock-boring and Drilling Machines.
We, JOHN EVAN POWELL, ROBERT JONES POWELL and WILLIAM WHITAKER, all
of Cambrian Iron Works, Wrexham, in the county of Denbigh, Engineers, 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 :-
Our invention relates to rock-boring and drilling machines, and has for its object
to simplify the construction of such machines and to render the samo more efficient
in operation than heretofore; and to these ends it comprises the improvements
hereinafter described.
In the accompanying drawing,-
Figure 1 is a longitudinal section of a rock-boring and drilling machine constructed
according to our invention; and,
Rigure is a plan of the same

page_text: Figures 8 to 11 are views of details more fully hereinafter described.
Similar reference letters indicate similar parts throughout the drawing.
In carrying out our invention we form the ports a (figures 1 and 4) through
which the compressed air or the like passes to operate the pistons b, within the dove-
tailed slide c, as shown most clearly in the said figures, the said slide being formed
integral with the cylinder d and sliding in the cradle e in a well known manner.
By this arrangement the ports a are protected from accidental damage more
effectually than if placed on any other part of the cylinder.
The ports a are formed equidistant from each end of the cylinder, and the main
inlet to the cylinder is formed midway between its ends and on both sides as shown
in figures 1 and 5. so that the sail cylinder can be reversed end for end in the
cradle e without difficulty in order to equalize the wear caused by the pistons b. By
thus allowing of the reversal of the cylinder it is enabled to last a longer time
without reboring than is the case with the cylinders of other rock-boring and drilling
machines.
In order to prevent any escape of air where the piston rod g passes into the
cylinder, instead of a stuffing box and gland as generally used, we make use of a
stuffing box has shown in figures 1, 2 and 3 in which we arrange one or more
metallic rings cut into two or more seginents. Around the rings we place india-
rubber or other elastic rings which serve to tightly compress the said rings upon
the piston rod g and thereby ensure an uniform tightness. h¹ is a plate which we
interpose between the box and cylinder & to keep the rings i and j in place.
i
The pistons are rotated in a well known manner by means of the twist-bar k,
ratchet wheel and pawls m figures 1 and 6. These pawls, however, we construct
double ended or with two bossus or projections m¹, one on each side, as shown in
figures 6 to 9, figures 8 and 9 representing a side elevation and plan of one of the
said pawls. The bosses or projections m take into holes in a platen and cover o
which form the chamber p within which the said pawls and ratchet wheel are
located. By this arrangement the pawls are supported on both sides which prevents
any liability of their breaking off, which often occurs when supported on one side:
only as in rock-boring or drilling machines as heretofore constructed.
In order to obtain additional air space at the rear end of the cylinder & we connect
the chamber p to the said cylinder by forming holes n' in the plate n. By this
arrangement we obtain additional air space without lengthening the cylinder, which
if carried out, would have to be effected at both ends of the said cylinder on account
of its reversibility. 9' are two bolts for holding the stuffing box h, plate h³,
cylinder d, plate n and cover o together.
For attaching the drill to the stretcher bar we provide a spring clip of novel
construction, as shown in combination with the drill in figures 1, 2 and 5, and
detached in side and end elevation in figures 10 and 11 respectively. The clip is
formed with two openings and s in which the bolt (attached to the cradle e) and
stretcher bar respectively are located. The metal surrounding the opening r is,
however, split midway between its ends so as to form two portions, as shown
clearly in figure 11, so that by the operation of tightening the nut t¹ upon the
bolt against the washer u, the portions are drawn together so as to clamp the
clip upon the stretcher bar g and at the same time fix the drill rigidly to the said
clip. By this construction of clip we dispense with the second bolt beretofore used
for clamping the said clip upon the stretcher bar and also with the lugs or ears used
in conjunction therewith; which lugs or ears have been frequently broken off when
the clip has been in use.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what
we claim is :-
(1) In a rock-boring or drilling machine of the kind herein described, forming
the ports within the

page_text: (2) In a rock-boring or drilling machine, the use of metallic rings formed in
segments in combination with india rubber or other elastic rings for producing an
air-tight joint where the piston rod passes into the cylinder, substantially as herein-
before described.
(3) In a rock-boring or drilling machine of the kind herein described, constructing
and arranging the pawls which operate in conjunction with the ratchet-wheel for
turning the cutter, so as to be supported on both sides, substantially as set forth.
(+) A new kind of clip, in which a single bolt and nut serves to lock the stretcher
bar to the rock-boring or drilling machine, substantially as described..
(5) The improved clip, substantially as herein before described and illustrated in
the accompanying drawing.
(6) The manufacture and use of the improved rock-boring or drilling machine,
substantially as hereinbefore described and illustrated in the accompanying
drawing.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.