Improvements in Rock Drilling Apparatus.
Year: 1897

page_text: Date of Application, 22nd Mar., 1897
Complete Specification Left, 11th Dec., 1897-Accepted, 5th Feb., 1898
PROVISIONAL SPECIFICATION.
Improvements in Rock Drilling Apparatus.
We, JULIEN DULAIT, of 1, Rue Prunieau, Charleroi, in the Kingdom of Belgium,
Engineer, and ROBERT FORGET, of 56, Rue de Londres, Paris, in the Republic
of France, Manufacturer, do hereby declare the nature of this invention to be
as follows:-
Our invention relates to a rock drill which is of special construction in all its
parts and is distinguished substantially by an elastic operating device transmitting
to the drill, during its feed and rotation, an axial percussion or to-and-fro move-
ment by a flexible part constituted by balls serving to transmit the rotary move-
ment of the motor to the mechanism for operating the rock drill.
In the improved rock drill the drill effects its percussion movement owing to
the mounting of its shaft in a spindle on the one hand under the action of a
spring and on the other hand under the action of an eccentric carried away by
an elastic fly wheel operated by gear wheels connected with the motor by the
flexible linked part.
The drill shaft which carries the drill is screw threaded throughout its length
and passed into the hollow spindle interiorly screw threaded so as to advance
axially in the spindle when it is turned with the aid of the fly wheel, the nave
of which turns on the spot in a corresponding bored boss of the frame and carries
away the drill shaft in its rotation by a key of a sleeve fitted and fixed by the
screws in the nave and whose aforesaid key travels in a corresponding groove
extending throughout the length of the drill shaft.
In a boss at the opposite extremity of the frame is fixed a sleeve held moreover
at its interior extremity by a nipple cast on the frame and passing laterally into a
corresponding cavity in the collar of the sleeve provided with a bearing in which
is guided in the middle the spindle guided moreover at its lower extremity by
two hoops in the enlargement of the sleeve. A strong helical spring wound
around the spindle and bearing on the one hand upon the said hoops and on the
other hand against the shoulder formed by the edges of the bearing tends to
move the spindle, shaft and drill outwards and thus keeps them in their normal
position. The spindle is guided at a third point in the frame by a transverse
piece fastened upon the upper extremity of the spindle by conical fitting and held
in its place by a ring screwed and secured by a pin upon the spindle which it
terminates. In a cavity in the transverse piece is placed a roller adapted to turn
loosely upon a bolt driven into the transverse piece and against the periphery of
the said roller acts the curved part of the eccentric in order to move back the
spindle and compress the spring which throws it again forward as soon as the
pressure of the eccentric upon the roller discontinues so as to realize by its two
actions the percussion movement of the drill which is also held exactly in the
axis of the system by a special tightening device in the thickness of the screw-
threaded drill shaft. The tightening device is composed of an oval sleeve which
is on the one hand engaged with the key having free play in a groove provided
in any desired manner at the extremity of the drill shaft and on the other hand

page_text: by a strong binding screw whose corresponding point bears upon the drill shaft.
The key rounded so as to fit the form of the rear part of the drill may be firmly
tightened against the latter through the medium of the sleeve by tightening the
binding screw. By this means I realize three essential points for the effective.
operation of the rock drill:
(1). A perfect solidarity of the drill shaft and drill.
(2). A perfectly rectilineal prolongation of the axes of this shaft and drill.
(3). The certainty of the contact of the flat extremity of the drill with the
bottom of the cavity in the piece.
We obtain moreover a great rapidity in the removal of the drill and lastly, when
it passes into the rock or for various reasons as regards the operation, by loosening
the binding screw it is possible to turn the drill shaft without carrying away
the drill.
The eccentric or cam is keyed upon a vertical cam shaft one extremity of which
turns and is guided in the collar of the spindle, whilst its opposite extremity is
free and carries the outer one of the halves in the form of a sleeve, of the elastic
fly wheel. The other or inner half of the latter presents the form of a double
cross provided on the vertical gear shaft which turns in the corresponding boss
of the frame and carries at the opposite extremity the bevel wheel with which gears
the bevel pinion keyed upon the shaft hereinafter called the motive shaft with
which is connected the motor by the flexible connection.
'
The nave of outer half of the fly wheel fits loosely into the nave of the inner
half so as to strengthen and to guide at the centre the two independent halves,
but connected to each other by helical springs hooked on both sides to pins passing
into the feet of the outer half and into the points of the crosses of the inner half.
By this elastic operating mechanism the action of the cam for compressing the
spring is transmitted progressively and thus prevents secondary strains and violent
shocks which might put the system out of order and twist or break the flexible
shaft which transmits them.
This flexible shaft is characterized by a junction by free balls of the limbs or
links which compose it. These limbs or links are sleeves presenting an exterior
profile which is preferably made oval, the two extremities being cut so as to form
claws having three claws alternately opposed. Between the claws interiorly
hollowed is placed a ball and the claws of one sleeve are placed
in the spaces between those of the following sleeve. The extremities
of the contiguous claws are squeezed or bent
which
upon the ball
is thus imprisoned between the six branches in such a manner that the sleeves
thus assembled can turn in all directions except the direction of rotation in which
they are operated. When thus operated the sleeves acting laterally against each
other are like a rigid shaft.
This chain of sleeves articulated upon balls is surrounded with a sheath capable
of following all the bending movements and at its extremities the flexible shaft
thus constituted is provided with the devices necessary for being attached to the
shaft of the motor and to the shaft of the percussion mechanism.
The rock drill is suspended as usual by suitable journals cast in one piece with
the sleeve carrying the drill shaft, in the adjustable lugs of a frame of appropriate
construction generally made of two rods connected by transverse pieces provided
with claws for securing the frame in position.
The motor, which may be of any suitable kind, as for example an electric
motor, is adjustable upon a column fastened upon the platform of a truck or
carriage with the aid of a support the essential part of which is a box articulated
upon the support and in which turns a cone cast on the frame of the motor so that
the latter may be placed and inclined in conformity with all the positions which
the rock drill may occupy.
At the front part of the platform of the truck or carriage is arranged a rigid
trestle of angle iron, the front transverse piece of which has two retreating parts
which embrace the rods or shafts of the frame when the carriage is pushed against

page_text: them in order to rock the frame upon the carriage or truck with a view to
facilitating the transport of all the material.
The operation of the system will be easily understood from the preceding
description.
When the rock drill suspended by its journals in the frame and the latter
placed upon the trestle has been transported to the spot where the work is to be
done, the frame is rocked, moved back and fixed in its place by its tightening
screws; the rock drill is inclined in the direction of the hole to be drilled and
tightened in the lugs of the frame. Then the flexible part attached on the one
hand to the motor is connected on the other hand to the shaft motive of the
elastic operating device, whose cam moves back the spindle and the drill shaft
with the drill then thrown forward again by the spring. In the meantime the
workman attending the machine turns the fly wheel and with it the drill which,
as it turns and advances, bores quantities of materials corresponding to the hard-
ness of the rock which is to be detached.
Dated this 22nd day of March 1897
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicants.
Improvements in Rock Drilling Apparatus.
We, JULIEN DULAIT, of 1, Rue Prunieau, Charleroi, in the Kingdom of Belgium,
Engineer, and ROBERT FORGET, of 56, Rue de Londres, Paris, in the Republic
of France, Manufacturer, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
Our invention relates to a rock drill which is of special construction and is
distinguished substantially by an elastic operating device transmitting to the
drill, during its feed and rotation, an axial percussion or to and fro movement
by a flexible shaft serving to transmit the rotary movement of the motor to the
mechanism for operating the rock drill.
The invention is represented in the accompanying drawings in which
Figure 1 is a longitudinal section of the rock drill with its percussion operating
device.
Figure 2 is a plan of the elastic fly wheel of the said operating device, and
Figure 3 is a plan of the escapement cam.
Figure 4 is an elevation of the frame carrying the rock drill.
Figures 5 and 6 are respectively a side elevation and a plan of the transporting
truck with the motor for operating the percussion mechanism, and
Figures 7, 8, 9, 10, 11 and 12 are details of the flexible shaft.
In the improved rock drill the drill effects its percussion movement owing to
the mounting of its shaft in a spindle on the one hand under the action of a
spring and on the other hand under the action of an eccentric operated by an
elastic fly wheel driven by gear wheels connected with the motor by the flexible
shaft.
The drill shaft A which carries the drill L is screw threaded throughout its
length and passes through an interiorly screw-threaded hollow spindle F so as
to advance in an axial direction in the spindle when it is turned. by means of
the fly wheel N. The nave M of this fly wheel turns in a correspondingly bored
boss of the frame C and operates the drill shaft A in its rotation through the
medium of a key c of a sleeve M¹ fitted and fixed by screws in the said nave M

page_text: the aforesaid key traversing in a corresponding groove extending throughout.the
length of the drill shaft A.
"
In a boss at the opposite extremity of the frame C is fixed a sleeve K held at
one of its extremities by a nipple t cast on the frame and pressing laterally into a
corresponding cavity in the collar of the said sleeve K. This sleeve is provided
with a bearings in which is guided the spindle F provided at its extremity with
two hoops or guide rings f f working in the enlargement of the sleeve. A strong
helical spring R wound around the spindle F and bearing on the one hand
upon the said hoops or rings and on the other hand against the
shoulder formed by the edges of the bearing S tends to move the
spindle, shaft and drill outwards and thus keep them in their normal position.
The spindle F is guided at a third point in the frame C by a transverse piece T
fastened to the other extremity of the spindle by conical fitting and held in its
place by a nut or washer B screwed and secured by a pin upon the spindle. In a
cavity in the transverse piece T is placed a roller g adapted to turn loosely upon
a bolt driven into the transverse piece and against the periphery of the said
roller acts the curved part of the eccentric E in order to move back the spindle F
-and compress the spring R which throws it again forward as soon as the pressure
of the eccentric upon the roller discontinues so as to effect by its two actions the
percussion movement of the drill L which is also held exactly in the axis of the
shaft by a special tightening device in the screw threaded drill shaft A. The
tightening device is composed of an oval sleeve 12 which is on the one hand
engaged with the key D having free play in a groove provided in any desired
manner at the extremity of the drill shaft A and on the other hand by a strong
binding screw I whose corresponding point bears upon the drill shaft A as shown
in the drawing. The key D rounded so as to fit the form of the rear part of
the drill L may be firmly tightened against the latter through the medium of
the sleeve Me by tightening the binding screws I. By this means we realize
three essential points for the effective operation of the rock drill:
(1). Perfect rigidity of the drill shaft A and drill L.
(2): A perfectly rectilineal prolongation of the axes of this shaft and drill.
(3). The certainty of the contact of the flat extremity of the drill with the
bottom of the cavity in the shaft.
We obtain moreover a great rapidity in the removal of the drill and lastly, when
it passes into the rock or for various reasons as regards the operation, by loosening
the binding screws I it is possible to turn the drill shaft A without moving the
drill.
The eccentric or cam E is keyed upon a vertical cam shaft A' one extremity
of which turns and is guided in the collar of the sleeve K whilst its opposite
extremity is free and carries one of the halves m in the form of a sleeve, of the
elastic fly wheel V. The other half m¹ of the latter presents the form of a double
cross provided on the vertical gear shaft A2 which turns in the corresponding
boss of the frame and carries at the opposite extremity the bevel wheel with
which gears the bevel pinion P keyed upon the shaft A³ with which is connected
the motor by the flexible connection or shaft G.
The nave of the outer half m of the fly wheel V fits loosely into the nave of
the inner half m¹ so as to strengthen and to guide at the centre the two independent
halves, but connected to each other by helical springs r hooked on both sides to
pins e passing into the feet p of the outer half m and into the points p¹ of the
crosses of the inner half m¹.
By this elastic operating mechanism the action of the cam E for compressing
the spring R is transmitted progressively and thus prevents secondary strains and
violent shocks which might put the system out of order and twist or break the
flexible shaft.
This flexible shaft is characterised by a junction by free balls of the limbs or
links which compose it. These limbs or links (Figures 9, 10, 11, 12) consist of
sleeves H presenting an exterior profile which is preferably made oval, the two

page_text: extremities being cut so as to form claws h having three claws alternately
opposed. Between the claws hollowed interiorly, is placed a ball i and the claws of
one sleeve are placed in the spaces between those of the following sleeve. The
extremities of the contiguous claws are squeezed or bent upon the balls i which
is thus imprisoned between the six branches in such a manner that the sleeves H
thus assembled can turn in all directions except the direction of rotation in which
they are operated. When thus operated the sleeves acting laterally against each
other are like a rigid shaft.
This chain of sleeves articulated 'upon balls is surrounded with a sheath G
capable of following all the bending movements and at its extremities the flexible
shaft thus constituted is provided with the devices necessary for being attached
to the shaft of the motor and to the shaft of the percussion mechanism.
The rock drill is suspended as usual by suitable journals Qcast in one piece
with the sleeve K in the adjustable lugs Ŭ of a frame of appropriate construction
generally made of two rods connected by transverse pieces provided with claws
for securing the frame in position.
The motor X which may be of any suitable kind, as for example an electric
motor is adjustable upon a column W fastened upon the platform of a truck or
carriage with the aid of a support S the essential part of which is a box S¹
articulated upon the support and in which turns a cone cast on the frame of the
motor so that the latter may be placed and inclined in conformity with all the
positions which the rock drill may occupy.
At the front part of the platform of the truck or carriage is arranged a rigid
trestle Z of angle iron, the front transverse piece 7 of which has two retreating
parts z which embrace the rods or shafts of the frame when the carriage is
pushed against them in order to rock the frame upon the carriage or truck with
a view to facilitating the transport of all the material.
The operation of the system will be easily understood from the preceding
description.
When the rock drill suspended by its journals Q in the frame and the latter
placed upon the trestle Z has been transported to the spot where the work is to be
done, the frame is rocked, moved back and fixed in its place by its tightening
screws; the rock drill is inclined in the direction of the hole to be drilled and
tightened in the lugs U of the frame. Then the flexible shaft attached on the
one hand to the motor X is connected on the other hand to the shaft B of the
elastic operating device, whose cam moves back the spindle F and the drill
shaft A and the drill is then thrown forward again by the spring R. In the
meantime the workman attending the machine turns the fly wheel N and with it
the drill which, as it turns and advances, bores quantities of materials corre-
sponding to the hardness of the rock which is to be detached.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:-
First. A rock drill characterized by the combination of a non-rotary spindle
in which is mounted the drill shaft with a screw thread enabling the shaft to
advance and turn independently of the spindle with an elastic operating device
actuated by a flexible shaft transmitting an axial to and fro or percussion move-
ment to the spindle and to the drill.
Second. In the rock drill herein before set forth the construction of the elastic
operating device characterized by a fly wheel made in two halves the naves of
which are fitted loosely into each other and the respective peripheries connected
with each other by intermediate springs, one of the halves being fixed upon the
driving shaft and the other half connected with an eccentric shaft or cam turning
against a roller upon the spindle and moving the latter back, the said drill shaft
being then thrown forwards by a strong spring surrounding it and tending to
move it in the direction in which the drilling is taking place.

page_text: Third. In the rock drill herein before set forth the flexible linked shaft charac-
terized by a succession of sleeves articulated together by their extremities
arranged in the form of alternative claws enclosing an intermediate ball between
two successive sleeves so as to be able to bend in all directions and to be operated
in the rotation by the lateral contact of the claws.
Dated th 10th de of Decombo 1907
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicants.