Improvements in Mining Machines.
Year: 1890

page_text: Date of Application, 3rd Oct., 1890-Accepted, 8th Nov., 1890
COMPLETE SPECIFICATION.
[Communicated from abroad by ELMER AMBROSE SPERRY, of 201, South Canal
Street, Chicago, Illinois, United States of America, Electrical Engineer.]
Improvements in Mining Machines.
I, CHARLES DENTON ABEL, of No. 28 Southampton Buildings, Chancery Lane, in
the County of London, Consulting Engineer and Patent Agent, 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 :-
This invention relates to mining machines of the kind wherein a percussive cutting'
tool carried by a portable framing has its working forward movement imparted to it
by a spring, the tool being drawn back so as to compress the spring by a motor
engine also mounted upon the framing and worked by electrical energy or other
motive force, the tool being released by a detent or otherwise for effecting its forward
stroke.
In the Specification to Patent No. 9509 of 1889 was described a machine of this
description in which the tool was connected to a crank pin by a pitman made elastic
in the direction of its length and having a slotted connection with the crank, the
latter being so connected to the motor that after having drawn the tool back against
its spring, it became detached from the motor so that it permitted the tool to be
thrown forward by its spring, after which it caught up the connecting rod again
so as to repeat the operation, the spring action of the connecting rod, preventing any
violent concussion when it was caught up by the crank pin again.
According to the present invention a still greater degree of elasticity is imparted to
the connection between the motor and the tool, so as more effectually to prevent the
concussions or vibrations to which the tool is subject from being imparted to the
working parts of the motor engine.
For this purpose the tool and the motor are carried upon one and the same rigid
frame as before, the motor being at one end and the tool holder working in guides at
the other end, but the tool holder is connected to. a loosely revolving crank by a
flexible or jointed pitman or connecting rod, while the crank is connected to a
revolving disc or wheel driven by the motor engine by means of a spring connecting
device so arranged that the spring is caused by the disc or wheel to impart to the tool
holder its backward stroke, and the spring connecting device being then disconnected
from the disc or wheel, the tool is thrown forward by its spring, and is then
immediately, at the commencement of the rebound, caught up without shock by the
crank which is elastically connected up with the disc or wheel again, so as to draw
the crank back against its spring again. Thus the force of rebound instead of being
spent in producing concussion and vibration is utilised for effecting the backward
stroke and consequently enables the motive power to be reduced to a proportionate
extent.
The arrangement of the said elastic and flexible connection is capable of being
variously modified. I will proceed to describe by way of example one arrangement
which I employ for this purpose which is shewn on the accompanying drawings.
Fig. 1 is a side view of the machine.
Fig. 2 is a plan view.
Fig. 3 a vertical longitudinal section.
Fig. 4a detail of the tool or pick.
Fig 5 detail of the carbon holder

page_text: on which
the internal gear. is journalled, and the journal box A' for the short shaft A. To
this piece A is secured the handle B and this portion is secured to the opposite
portion of the frame B₁, which is preferably made of a single piece. The two are
bolted together by the bolts B2 B². The portion B' is provided with the trunnion B
journalled the wheel B and to it is secured the electric motor consisting
of the field magnet B³, pole pieces B6, armature B', commutator B and switch B
Upon the pole piece is secured the handle B and the cap B" for the exterior of
the armature. C is a cross shaft passing across frame carrying the armature at one
end and the fly wheel C at the other and journalled at C² on the frame piece B
This shaft also carries the pinion C³ which gears with the wheel C on the shaft A
This shaft also carries the pinion C which gears with the large wheel C which has
a backward extending hollow journal C which is received into the box A³. A
portion of the casting A serves as a casing of this wheel C. The frame B extends
forward as indicated so as to form a suitable guide for the operative parts of the
machine. Journalled within the hollow journal is one end of the crank D the
other end of which is journalled upon the frame or in the field magnet, and the crank
pin of which is provided with the sleeve or pulley D¹ running with a ball bearing D³
on the pin.
Embracing this sleeve or pulley is the pitman strap E pivotted to a pin E' in the
slide E2, the lateral extensions of which E3 E³ rest upon the top of the extended
portion of the frame B' and beneath the guide bars E E which are bolted to the
frame. Secured to the slide E2 by the key F is the reciprocating bar or tool
holder F which passes through the extremity F2 of such projecting frame B¹.
Between this extremity and the slide E2 is disposed the packing or elastic cushion F³
and within the outer cylindrical portion of such end is the tube F within which lies
the helical spring F surrounding the bar F. At the outer extremity of the tube F³
is the slide against which bears the other end of the spiral spring F. G is the
pick point or percussive tool secured by the key G' to one end of the tube G², the
other end of which is secured by the key G³ to the end of the rod F¹. The slide F
encloses the inner end of the tube G². This tube has the transverse slot G* for the
purpose hereinafter set forth. J is a curved spring lying upon and within the gear
wheel C and having the hook or loop J (Fig. 1) at one end secured to the lug J³
on the crank and at the other secured to the pawl R. The fly wheel C' is composed
of the exterior solid portion and the interior part K which is keyed upon the shaft C
and has the projecting ends K'K'. Between these ends and the inner projections K² K²
are disposed the elastic cushions K* K* to make the connections between the shaft
and the heavy portion of the fly wheel elastic.
It is obvious that similar devices could be employed for elastically connecting any
of., the wheels with its respective shaft. These elastic connections are exceedingly
important in a machine of this character.
The spring F is secured to the pawl R which is itself pivotted between the bifurcated
ends of the supporting arm R¹ which is pivotted at R² to the projecting end R³ of the
crank D, and is slotted at R so as to permit of its lateral movement on the pivot R²,
while the journal trunnions R' of the crank D passes through the slot. A circular
ratchet R is formed in the inner portion of the wheel and in it is adapted to
play the pawl R. This pawl is pressed outward against the ratchet teeth by the
spring R
It will be seen from the above that the operation is as follows: On the rotation of
the wheel R' in the direction of the arrow Fig. 3, the pawl R engages the ratchet Re
and thus by means of the spring J draws backward the elastic pitman Ę the end of
the spring J being secured permanently to the pin J³ (Fig. 1) as described.
When the parts have reached a certain position the pawl and ratchet will no longer
hold the spring J against the force of the compressed spring F whereupon this will
force the pick forward and will carry round the crank and pawl and the spring J as
long as the pawl moves faster than its ratchet; as soon as the blow is delivered and
the power is taken from the elastic pitman E, the said pawl will immediately be
acted upon by the ratchet R and will carry the spring F round with it until the crank

page_text: pin again exerts a pull upon the elastic pitman E so as to compress the spring F and
draw back the pick.
T Fig. 5 is a block supported over the commutator B8, and T¹ is a carbon on which
lies the plate T2 which is forced downward by the spring arm T3 to keep the carbon
against the commutator.
The pitman E may either be of the elastic looped form shewn, or it may be of a
flexible or jointed form shewn in my application of equal date herewith. By the
looped form of connection with the crank pin shewn, the latter is free to continue its
rotation independently of the position of the tool and pitman, which may perform either
the full stroke or only part thereof, and by the spring connection of the crank
with the wheel Co, any shock consequent on the reengagement of the crank pin with
the end of the loop of the pitman will be prevented from being transmitted to
the motor.
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 :-
1. In a mining machine operating with a percussive tool the blow of which is
effected by a spring, while the backward motion of the tool against the spring is
effected by a motor engine on the framing of the tool, effecting the connection of the
tool holder with the motor engine through an elastic flexible or jointed pitman or
connecting rod and a crank pin connected with the motor through a spring connecting
link so that the shock of impact of the tool and of the reengagement of the pitman
with the crank pin is in great measure prevented from being imparted to the motor
engine, and the continuous movement of the latter is not checked by the impact of
the tool, substantially as described.
2. In a mining machine operating with a percussive tool the blow of which is
effected by a spring, the connection of the tool holder with a revolving wheel or disc
driven by the motor by means of a curved spring one end of which is attached to the
pin of a loose crank engaging with the looped pitonan of the tool holder while the
other end is provided with a pawl or catch that engages with a toothed ring on
the said wheel or disc in such a manner as to be carried round thereby for effecting
the backward motion of the tool, and to be released therefrom at the forward motion
of the tool, substantially as described.
3. In a mining machine such as is referred to in the preceding claims the use of
an elastic looped pitman E constructed as herein described with reference to the
drawings.
4. In a mining machine operating with a percussive tool, the blow of which is
effected by a spring, the combination of the tool slide E2 with the flexible or elastic
looped pitman E loose crank D, arm R' pivotted to the crank, spring J connected at
one end to the crank D and at the other end to the arm R', and spring pawl R gearing
with the ratchet teeth R of wheel C, substantially as described.
5. In a mining machine operating with a percussive tool, the blow of which is
effected by a spring, the combination of the framing made in two halves A and B',
the slide 2 carrying the tool holder F and sliding in guides E, the elastic buffer F
for the slide to strike against, the elastic looped pitman E pivotted to the slide and
looped round the crank D, the spring J permanently connected at one end to the
crank D and intermittently connected at the other end by the pawl R and ratchet R*
with the wheel C, the electro-motor B' B6 B7 driving the wheel C through toothed
gearing, and the elastically coupled fly wheel K K' K K', substantially as described.
Dated this 3rd day of October 1890.
ABEL & IMRAY,
Agents for the Applicant.