Improvements in the Construction and Arrangements of Machines for Cutting Coal and other Minerals.
Year: 1889

page_text: This Specification was, upon the 14th day of December 1891, Amended under
Sections 18 to 21 of the Patents, Designs, and Trade Marks Act, 1883.
The Amendments are shown in erased tuve.]
Date of Application, 6th Sept., 1889-Accepted, 28th Dec., 1889
AAMDI BATE
CUBCON
Improvements in the Construction and Arrangements of Machines
for Cutting Coal and other Minerals.
LLEWELYN BIRCHALL ATKINSON, Erwood, Beckenham, Kent, Civil Engineer
CLAUDE WILLIAM ATKINSON, Erwood, Beckenham, Kent, Engineer, WALTER THOMAS
GOOLDEN, Woodfield Road, Harrow Road, London W. Electrical 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:—
This invention has for its object the improvement of machinery for cutting coal
or other minerals, by electric power, by providing a compact combination of electric
motor & coal cutting machine, in which the magnetic framework of the motor
and the framing of the machine are combined. The machine shewn in figs. 1, 2, 3
consists of a base (a) mounted on wheels with double or single flanges to work on
the rails of the mine or pit.
In the centre of this base is a circular cavity having a central pin in which is
secured by guides the circular base of the machine, as described in the Specification
of Letters Patent No. 1409087.*
The whole machine consisting of the motor, gearing, & cutter shaft can he
rotated by means of the worm wheel and worm segment "c" and "d."
Figs. 1 & 2 shew the arrangement where a horizontal double field motor is used.
Here the block (e) which is in one casting with the circular base forms the support
for the bearings of the shaft which carries the cutter (f.) the shaft passing right
through the block which also forms the bottom pole piece of the motor. The
extensions of this block in front and behind carry the bearings of the armature shaft,
which is parallel to the lower or cutter shaft, and gears with it by means of the
wheels (9) (h) which are preferably double helical teeth wheels. The caseing (),
preferably of non-magnetic metal, covers in the wheels to prevent the access of dirt.
The armature is enclosed by the side plates (k) (k) and the front end cover (l.) and
back covers (m.) which are removable, these covers being to exclude dirt and to
provide against danger from explosive gases as described in letters patent No. 1267687.
The magnetizing coils are wound on wrought iron cores, and the top pole piece (o)
completes the motor.
The lubrication is effected by the lubricators (p.) which have spring lids readily
opened; without loose parts. The internal lubricator comprises a drip lubricator, the
drip being started or stopped by turning the catch (q.) a quarter of a turn which
slightly raises the coned spindle' (r.) allowing oil to pass. Pipes lead from these
lubricators to the bearings, and the excess oil drains into reservoirs cored in the
framework of the machine, and into the wheel box, which is made oil tight, thus
thoroughly lubricating the gearing.
The magnet coils are enclosed in a sheet steel or copper lagging to protect
the wire from mechanical injury and to diminish the electric monentam of the
circuit.
Fig. 3 shews the modified arrangement where the motor is of the inverted vertical
type, and shews an arrangement of chain gear which may be adopted instead of wheel

page_text: gearing. The coverings & general arrangement are in this case similar to those
already described.
The electric motor is started and stopped by the switch constructed as follows. On
an insulating base bolted to the machine is mounted a switch fig. 4 with four or
more consecutive contacts (a, a, a, a) and one isolated contact (6). Round the
switch proper is an insulated metal cylinder on which a resistance wire is wound,
and connected at intervals to the points of the switch. The whole is enclosed in a
metal caseing practically air and gas tight (d). Fig. 5 shews diagramatically the
arrangement of the switch, and its connections to the motors shewn in figs. 1, 2 & 3
the switch in the latter case being preferably attached to the back of the pole piece.
The action is as follows
On making the circuit the switch bar passes over the various points of the switch
and thereby short-circuits the resistance gradually, allowing the machine to start
steadily.
On moving the switch to stop the motor the resistance is gradually inserted
and finally, at the moment of breaking, by means of the isolated point of
contact (b) the magnet coils are short circuited thus diminishing the spark very
considerably.
In certain cases for convenience of transport of the machine, in addition to the
ordinary wheels on which the machine is worked, two other cross axles and wheels,
with bearers are provided, the said bearers fitting into recesses on the under side of
the machine. When it is required to move the machine about, the machine is raised
and these axles and wheels placed underneath, and the machine then being lifted
off its ordinary wheels can be run on the rails of the pit and round curves of short
radius.
Having now particularly described and ascertained the nature of our said
invention, and in what manner it is to be performed, we declare that what we
claim is
1. The construction of machines for cutting coal or other minerals by electric
power, in which the framework of the coal cutter forms part of the magnetic frame-
work of the motor as described.
2. The construction of machines for cutting coal or other minerals, composed of a
horizontal or vertical electric motor, with a cutter shaft below or parallel to the
armature shaft, and gearing with it, the said shaft, being carried in or upon the
pole piece or magnet yoke of the motor as described.
3. The construction and arrangement of electric coal or mineral cutting machines
as described and illustrated by Figs. 1. 2. 3.
4. The combination with coal cutters as described of a separate pair of axles,
attachable to the underside by raising the machine above its working wheels, and
having a shorter wheel base than the working wheels.
5.-The--construction--and--arrangement--of-switch, comprising-switch-resistance
wound-on-metal-cylinder, contacts, & short cireuiting point, enclosed in metal covering
as-described-&-illustrated-in-figs. 4-und-a.
Dated this 5th day of Santamber 1990
LLEWELYN B. ATKINSON.
CLAUDE W. ATKINSON.
WALTER T. GOOLDEN.