Improvements in Apparatus for Boring or Perforating Rock.
Year: 1898

page_text: Date of Application, 25th Feb., 1898
Complete Specification Left, 23rd Nov., 1898-Accepted, 25th Feb., 1899
Improvements in Apparatus for Boring or Perforating Rock.
I, JOHN OWDEN O'BRIEN, M.I.Mech. E., of the Firm of W. P. Thompson and
Co., of G, Bank Street, Manchester, Liverpool, and London, in the Counties of
Lancaster and Middlesex, respectively, Patent Agents, (a communiation to me
from Camille Bornet, of Rue Saint Ferdinand, Paris, in the Republic of France,
Engineer,) do hereby declare the nature of this invention to be as follows:-
This invention relates to improvements in connection with a new percussion
and air spring perforating machine. The perforator is composed of a cylinder
preferably cast iron, enclosing the percussion rod and the parts which serve
to operate it and carrying in front my central water injection arrangement for
the automatic clearing of the shot hole in a mine, and at the back the driving
shaft operated either by a flexible belt or a rotary electric, or other motor and
driving by means of a connecting rod and crank the percussion rod. Finally the
part can slide lengthwise on to a support which controls the direction of the per-
forator and carries the screw.
This perforator, being worked by a crank and connecting rod, requires inter-
posed between the percussion rod and the driving bar on the crank of the shaft
some elastic fitting for the purpose of preventing the shock of the blow upon
the rock from reacting direct on the driving shaft. For this purpose the follow-
ing construction is employed;-
The frame is composed of two cylindrical parts of different diameters, and the
percussion rod is fitted with a long cylinder which can slide into the cylindrical
part and carries externally a long loose sleeve movable in the cylindrical part,
the function of this ring being to cause the tool to revolve upon itself after cach
blow struck upon the rock, as will be described subsequently.
In the interior of the cylinder a piston moves, which is composed of two pieces
connected by a rod and derives its motion from the rod linked to the crank of
the driving shaft. Between the two pistons is placed a full disc fixed to the
cylinder in such a way that two air chambers are formed at the sides of this
disc and act in the following manner.
When the pistons recoil a partial vacuum is created in one chamber whilst
the air in the other chamber is compressed and forces the disc and therefore the
percussion rod to recoil; and when the pistons advance the reverse takes place;
the air contained in the chamber is compressed, acts on the disc and forces the
percussion rod forward as well as the punch attached to the end.
This application of an air spring to percussion perforators possesses this impor-
tant advantage; it supersedes the metal springs hitherto used for the same pur-
pose and which are liable to break after being in use for some time owing to the
numerous and incessant concussions to which they are subjected.
In order to prevent air escaping from the periphery of the pistons, which
would quickly frustrate the effect intended, there are made in the frame of the
cylinder openings which, without interfering with the working of the contriv-

page_text: ance, allows the external air to penetrate the chambers during the periods when
a partial vacuum is produced as explained already.
When the pistons recoil and the air is rarified in the first chamber this cham-
ber soon gets into communication with an opening terminating externally and
through which a certain quantity of air will be able to at once enter the cham-
ber. in the same way when the pistons advance and the air of the other chamber
is rarified there will be simultaneously produced an influx of air into tuis cham-
ber coming through the opening.
In order to ensure the perfect lubrication of this apparatus the cylinder is made
with two orifices the former being used for lubricating the sleeve and the latter
for lubricating the pistons and the rod carries two lubricators, one for the crank
and the other for the pin connecting the said rod with the piston and finally a
cover of sheet metal encloses the back part of the perforator and prevents the
dust from the mine gaining access to the mechanismi.
To complete the description of the perforator I will explain in a few words the
working of its principal remaining parts such as the arrangement for the central
injection of water, the rotating mechanism of the percussion rod, and the appa-
ratus for advancing or moving it forward.
In the arrangement described the injection of water for clearing the bore hole
of the mine is effected as follows;-
The second cast iron cylinder carries a small tube through which the water
under pressure passes, and enters an annular chamber through which runs the
percussion rod.
This rod has a central channel communicating by means of an.
oblique passage with the chamber, serving to carry the water into a conduit
made in the axle of the tool which is fixed in the cavity in the end by means
of a binding screw.
In order to prevent any escape of water, the annular chamber is adjusted in a
long socket the ends of which are made watertight by means of packing rings
which are kept close fitting by a screw cap. For the same purpose the cavity is
made with an annular groove in which an india rubber ring is fitted and forms a
joint with the end of the bar of the punch which is fitted into this cavity.
In this arrangement the chamber constantly fed by water under pressure only
occupies the front part of the socket, so that the oblique end of the channel
ceases communication with this water chamber every time the percussion shaft
recoils, the result being that the injection of water only takes place when the
percussion shaft completes its forward movement and commences its backward
movement, so that the consumption of water does not exceed the quantity neces-
sary for the work in hand.
in order to cause the tool to revolve after each impact of the punch the peri-
phery of the above mentioned sleeve is made with oblique grooves, the sides of
which are inclined in such a way as to enable them to slide under the similarly
inclined top of the spring snug fixed in the part cast upon the frame, conse-
quently every time the percussion shaft recoils it is forced to turn upon itself at
an angle corresponding to the width of one of the grooves of the sleeve. This
arrangement often used for the same purpose may be replaced by any equivalent
one which may be desired.
In conclusion the advancing and withdrawing movement of the perforator is
produced simply by means of the screw which is driven by hand by means of
the handle and is kept in its place by a rod firmly connected with the above
mentioned support in which the cylinder slides. This support also carries on its
upper part a wormed or screwed cone which holds a cross bar connecting the
perforator with a frame fixed to the sides of the gallery and enables it to be
turned in any direction according to the requirements of the work.
1
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1000

page_text: Wing statement
This invention relates to improvements in connection with a new percussion
and air buffer boring machine.
Referring to the drawings;-
Fig. 1 is a longitudinal section.
Fig. 2. Ground plan.
Fig. 3. Back view.
The apparatus is composed of a cylindrical body A, preferably cast iron, enclos-
ing the percussion rod C and the parts which serve to operate it and carrying
in front a central water injection arrangement B for the automatic clearing of
the shot hole in a mine, and at the back the driving shaft D operated either
by a flexible belt or a rotary electric or other motor, and driving by means of
a connecting rod and crank, the percussion rod. Finally the part A can slide
lengthwise upon a support E which controls the direction of the boring tool and
carries the screw F.
་
This boring tool being worked by a crank and connecting rod requires inter-
posed between the percussion rod C and the driving bar G on the crank of the
shaft some elastic fitting for the purpose of preventing the shock of the blow
upon the rock from reacting direct on the driving shaft. For this purpose the
following construction is employed.
The body A, as will be seen from Fig. 1, is composed of two cylindrical
parts a and a of different diameters, and the percussion rod C is fitted with a
long cylinder J which can slide into the cylindrical part a' and carries externally
a long loose sleeve H movable in the cylindrical part a, the function of this
sleeve being to cause the tool to revolve upon itself after each blow struck upon
the rock, as will be described subsequently.
In the interior of the cylinder Ja piston moves, which is composed of two
pieces, and i¹ connected by a rod I and derives its motion from the connecting
rod G linked to the crank d of the driving shaft D. Between the two pistons, i
and is placed a solid disk k fixed to the cylinder J in such a way that two air
chambers g and glare formed at the sides of this disk and act in the following
manner.
When the pistons i, i move back a partial vacuum is created in the chamber g,
whilst the air in chamber g¹ is compressed and causes the disk k and therefore
the percussion rod to move back; and when the pistons i, advance the reverse
takes place; the air contained in chamber is compressed, acts on the disk k
and forces the percussion rod forward as well as the punch attached to the end.
This application of an air cushion or buffer to percussion boring tools possesses
this important advantage it supersedes the metal springs hitherto used for the
same purpose and which are liable to break after being in use for some time
owing to the numerous and incessant concussions to which they are subjected.
In order to prevent air escaping around the periphery of the pistons, which
would quickly nullify the effect intended, there are made in the wall of the

page_text: cylinder J apertures and which, without interfering with the working of the
contrivance allows the external air to penetrate the chambers g and g during
the periods when a partial vacuum is produced as explained already.
When the pistons and move back (see Fig. 1) and the air is rarified in
chamber this chamber is put into communication with the aperture terminat-
ing externally, and through which a certain quantity of air will be able to at
once enter the chamber. In the same way when the pistons and advance,
and the air of the chamber g' is rarified there will be simultaneously produced
an influx of air into this chamber through the aperture 4.
Fig. 4, shows a simpler arrangement which is often preferable to the cylinder
in which the air acts as a spring or buffer. In this case the form of the body A
and the cylinder J Fig. 1, is slightly modified and takes that shown in A' and J
(Fig. 4). The partition in Fig. 1 is omitted and a single piston moves in the
interior of the cylinder J which is closed at the back by a cover screwed on
the cylinder. The top of the rod G₁ serves to guide the rod in a rectilineal move-
ment. The introduction of air instead of being effected by two apertures such
as and of Fig. 1 is made by the single opening 2 situated in the middle of
the cylinder. Before the piston begins its forward movement, that is, to pro-
ject the percussion rod, the aperture allows air to enter in the front of the
cylinder which is compressed by the piston which closes the opening 12. When
the piston is at the end of its forward stroke the air enters at the back of
the cylinder by the opening 12 and is there compressed by the piston as it moves
backwards closing at the same time the opening . The other part of the
arrangement and functions are similar to that explained in Fig. 1.
To ensure the perfect lubrication of the mechanism the body A (Fig. 1) is pro-
vided with orifices m and m¹ the first serving to oil the sleeve H, and the second
to oil the pistons and it, and the connecting rod G carries the two lubricators,
one for the crank d and another j for the pivot which attaches this rod with
the piston i. A sheet iron cover n encloses the back part of the apparatus and
prevents the dust from the mine penetrating into the mechanism.
The following, description shows the functions of the other principal parts of
the boring apparatus, such as the arrangement of the central injection of water,
the mechanism for rotating the percussion rod, and the feed mechanism.
In the arrangement shown, the injection of water for clearing the shot hole is
effected in the following manner;-
The iron frame B has an inlet tube b through which the water under pressure
flows in to the annular chamber b¹ traversed by the percussion rod C. This rod
is pierced by a central passage e¹ communicating by an oblique passage with the
chamber and serving to direct the water in the pipe prepared in the axis of the
punch or tool which is fixed in the socket c² by means of a set screw.
To prevent any escape of water, the annular chamber 6 is provided with a long
socket 6 the ends of which are rendered watertight by means of round washers
of greased leather 63 which are kept in position by a cap b+ as is shown in the
drawing. For the same purpose the bottom of the socket is provided with a
circular groove which contains a ring of india-rubber which forms a joint with
the end of the punch or tool which is fitted into this socket.
In this arrangement the chamber b is continually fed with water under pres-
sure which does not extend to the back part of the end of the sleeve so that
the oblique end of the passage c¹ ceases to communicate with this water chamber
cach time the percussion rod moves back; as a result the injection of water only
takes place when the percussion rod has finished its forward stroke and begun
its return so that it reduces the outlay of water and the quantity necessary to
obtain the desired purpose.
To effect the rotation of the tool after each impact of the punch the sleeve H
is provided (as shown in Figs. 5 and 6) along its periphery with helical or spiral
grooves, one side of such groove a being perpendicular to the axis of the sleeve

page_text: and the other side a¹ inclined. In lugs h¹ cast upon the frame. A, a pin or
tooth his held in position by a spring, and the nose of such pin h is shaped to
be adapted in the oblique grooves. The feature is such that when the per-
cussion rod is moving backward, that is in the direction of the arrow K, the ver
tical faces a of the groove and of the pin are in contact and the tool is caused to
rotate to a degree corresponding to the circumferential inclination of one of the
grooves, but when the percussion rod is moving forward in the direction of the
arrow K¹ the inclined faces a¹ of the pin and of the groove are pressed one against
the other and on account of the percussion rod opposing resistance to rotate by
reason of the frictional contact with the rock, the nose of the pin h-which is
kept in position on the inclined face a¹ by the spring-mounts the oblique face
of the groove and falls into the next, in such manner that at each stroke the
tooth passes from one groove to another. This arrangement often employed for
the same purpose can be replaced by any equivalent one if wished.
The feed and withdrawal of the boring tool is effected by means
of the screw F which is worked by hand by the handle f and is kept in
place by a rod e firmly attached to the support E in which the frame A
slides as shown in Figs. 2 and 3. This support E carries also on its upper part a
lug or socket with internal screw which engages a transverse bar K which serves
to connect the apparatus with a frame fixed to the sides of the gallery and
enables it to be set or turned in any direction according to the nature of the work
to be effected.
The said boring apparatus is arranged for working by a motor, an air com-
presser, hydraulic or electric, either by intermediate flexible shaft or by any other
appropriate means.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is:
1. A percussion boring apparatus actuated by a rod and crank or by any other
appropriate fashion in combination with a buffer or cushion of air interposed
between the moving part and the percussion rod to replace the metallic springs
previously employed in the manner substantially as described.
2. In a boring apparatus, a metallic cylinder carrying at the end a percussion
rod, in which cylinder moves a double piston actuated by a moving rod and of
which the two parts are separated by a solid disk fixed to the cylinder in such
a manner as to form two air-tight chambers in which the air is alternately com-
pressed and expanded and thus causing without shock the backward and forward
movement of the percussion rod substantially as described.
3. To compensate the escape of air in the two piston chambers, apertures in
the walls of the chambers arranged in such a way that the working of the pistons
opens them alternately and allows the exterior air to penetrate at the moment
when the air which they enclose is most rarified, substantially as described.
4. In a boring apparatus, a metallic cylinder attached to the back of the per-
cussion rod, as shown in Fig. 4 in which cylinder a single piston moves, enclosed
by a cover and worked by a movable rod, a single aperture for the entrance
of air practically in the middle of the cylinder J¹, such aperture being uncovered
by the piston 22 in its extreme positions to allow the entrance of air which is
then compressed in the front part of the cylinder when the piston moves forward
and in the back part of the cylinder when the piston moves backwards substan-
tially as described.
5. The special construction and arrangement of boring apparatus represented
in the drawings comprising;-
;-
a. An air cushioned piston working the percussion rod and actuated by a
rod and crank by means of a shaft receiving movement from a flexible
transmitter, a rotary electric or other motor,

page_text: b. A passage or channel for the central injection of water through the exis
of the tool holder to insure the clearing of the shot hole in the mine after
each impact or blow of the tool.
c. An automatic mechanism to cause the rotation of the percussion rod
carrying the punch.
d. A grooved support with a feed screw fitted to a frame to allow the
setting of the apparatus.
Dated this 22nd day of November 1898.
WM. P. THOMPSON & Co.,
Manchester, Liverpool, & London, Patent Agents.