August 7, 1914.

THE COLLIERY GUARDIAN.

321

Some Recent Improvements in Prussian Mining Practice.

ZEITSCHR1FT FUR BERG=, HUTTEN- UND SALINENWESEN.

Preventing Accidents after Miss-Fires.—Trials n ade
in the Kdnigshutte State Colliery with the Muller safety
plug (fig. 1) for preventing accidents in boring out miss-
fire cartridges, have resulted in the general application
of this plug throughout the pit. As shown in fig. 1, two
wooden plugs are inserted into the shot-hole after the
blasting charge, and the fuse is passed through a central
bore in the plugs, which prevent the boring out tool from
coming into direct contact with, and exploding the
charge, since, on the one hand, the wood offers mere
resistance to the tool than the stemming, and on the

JE. " w"a
z 'ilr. 2nd Pluv

Fig. 1.

Pit (Herne) for about 18 months. The frame a, into
which the tub b is run, is provided with vertical shafts
c, d, e, f, driven by belt pulleys h, at the. top, and
carrying the scrapers g. These shafts are connected in
pairs by jointed levers i, which in turn are connected by
levers I. The ropes m and n, which pass over the rollers
u, and carry the counterweights, engage with the middle
of the lever I, as does also the rope o, which is passed
over rollers w, wound round the drum x, and attached
to the under side of the counterweight. All the joints
have sufficient play to allow for slight differences in the
vertical position of the shafts, and enable the latter to
operate when the encrusting material in the tubs is of
irregular thickness. The belt pulleys h, are driven from
the shaft q, and the vertical thrust is taken up by the
ball bearings r and s. On throwing the four spindles into
gear, the motion is transmitted by straight and crossed
belts t, pulleys for which are loosely mounted on their
shafts when at rest. The friction couplings v1, which
slide on keys, turn the pinions r1, R1 (keyed on the
shafts v) and transmit clockwise motion or the reverse
to the drum xf according as the spindles c, d, e, f are to
be raised or lowered. The couplings are operated by the
lever y. The tubs are moved by hand, a 7J-horse power
polyphase motor being used for driving the machine.
When the crusted dirt in the tub has been loosened by
the steel brushes of the scrapers, the tub is pushed into
a tippler, and discharges the loosened material into a
storage bunker. About 860 tubs are cleaned per double
shift, and 14 to 16 tub loads of small coal are recovered.
Each tub is cleaned about once every three days. The
machine requires the services of one man and two
youths.

Side-Tippler for Stowage Tubs (fig. 3).—This tippler
is used at the Neu-Iserlohn II. shaft. It consists of a
fixed frame a, and a cradle 6, the latter provided with
angle irons c, which engage with the tub axles. A lever
d keeps the cradle normally in a horizontal position,
but when a tub is run on to the tippler, and the locking

the latter have to be attached to the chain at intervals
of about 45 ft. For this purpose the automatic
regulator is set up about 6yds. away from the branch
roads where the full tubs enter the main road. The
device consists of a brake beam a, hinged on a wall
of the roadway; a wooden wedge b, adapted to move up
and down behind the beam a; rollers c and d (with
draught rope), for moving the wedge; a stop lever e,
mounted on the track about 6 ft. from the beam a; and
a releasing lever /, mounted at tub height on the wall
of the road, 45 ft. from the brake beam. The lever e
is connected to the thin end of the wedge, and the
lever /, to the thick end, by i in. ropes passing over
the rollers c and d. When tub 1 passes the turned back
brake beam a, the lever e is turned over by contact with
the tub axle, and draws down the wedge b, bringing
the beam a into the position shown. Tub 2 on reaching
tl^e brake beam is pressed by the latter against a rail g,
and is thus stopped. After tub 1 has caught on to the
chain at xf its forward movement brings it in contact
with the releasing lever f, which draws up the wedge
and releases tub 2. The series of operations is repeated
on tub 3 and the others in succession.

Automatic Distributing Switch at Pit Eye (fig. 5).—
At the same pit an automatic distributing switch is in
use to facilitate loading the cages at the pit eye. The
tongues of the switch are connected together by a flat
crossbar a, to which a bolt b is secured in the centre.
Near this bar is a fixed stay c, connected to the rails
and carrying at its centre a bolt d, on which pivots a
3-arm lever e. Near the root of the switch a 2-arm
lever f is arranged on each track, each of which levers,
alternately, projects far enough above the rail head to
strike against, and be turned over by the angle irons
on the underframe of the tubs. Rods connect the
levers f with the 3-arm lever e, so that there is always
one lever standing up and the other out of
the way. The third arm of the lever e is
connected by a spring g to the bolt b of the
movable crossbar a. As soon as either of the levers /
is depressed by an oncoming tub, the other lever is
raised, the 3-arm lever e is reversed, the spring g
pulls the crossbar a, and the switch points towards the
opposite side. The spring g causes the points to fit

Elevation.

Cross-section.

Side v ew.

7t





Plan.

other the appearance of the wooden shavings indicates
that it is time to stop boring any further. When the
fresh charge is inserted and fired, the flame passes
through the holes in the plugs and ignites the old charge.
By using two plugs only the front one is destroyed in
boring out the hole after a miss-fire; and the charge
remains protected until re-fired.

Machine for Cleaning Pit Tubs.—The machine illus-
trated in fig. 2 has been in use at the Victor III./IV.

device is released, the tub over-balances and tilts the
cradle until the angle irons c rest in recesses in a trestle
e. The tub can be easily lifted upright again.

Regulating the Distance of Tubs in Haulage Roads
(fig. 4).—At the Riesser lignite mine, Arnsdorf (West
Halle), the distance between the tubs in the main
haulage road is regulated automatically. This road
consists of a number of inclined sections with level
sections between, and to prevent the tubs from colliding,

Fig. 2.

closely every time, so that the working of the switch
is not endangered by any lost motion in the parts.

In addition, a main distributing switch ranges four
tubs—a cage load—at a time on to one track. In this
switch the crossbar a, of the two movable tongues is
prolonged on both sides, and is provided on one side
with a block h. The points are operated by the tubs,
for which purpose a single lever i is mounted so as to
pivot at k, in the adjacent rail. Under the rail is a
bolt Z, carrying a ratchet wheel m with disc n, and a
2-arm lever o, with pawl p, spring q, and counter-
weight r. The shorter arm of the lever o is connected
to the lever i by lashings s. The counterweight keeps
the lever i in the upright position. The ratchet wheel m
has 16 teeth, and the disc n, secured to same, is pro-
vided with four peripheral openings, shaped so as to
allow free passage to the block h on the crossbar a. Each
time the lever i is depressed by the flanges of a tub
wheel, the ratchet wheel m, and the disc n are moved
forward a distance of one tooth. When the wheel has
advanced four teeth, and four tubs have passed the
switch, the block h on the crossbar a is forced into
one of the openings in the disc n by the pull of the
spring g, which changes the switch over. Consequently
the next tub (the fifth) runs on to the other track,
depressing the lever f and stretching the spring g in the
other direction, until the eighth tub has passed, where-
upon the switch changes over again in the same way
as before. To the longer arm of the lever o is attached
a wire t, which is carried close up to the pit eye and
enables the hooker-on to work the switch, when timber
tubs, etc., are being hauled. In such case the second
pawl u holds the ratchet wheel in position to allow the
tub to run through. A similar installation is provided
at the pit bank.