January 28, 1916.

THE COLLIERY GUARDIAN.

189

ABSTRACTS OF PATENT SPECIFICATIONS
RECENTLY ACCEPTED.

457 (1915). Improvements in Jigs. W. P. Thompson,
of 6, Lord-street, Liverpool. (Communicated by Guy H.
Elmore, c/o American Concentrator Company, Weightmann
Building, Philadelphia, U.S.A.)—Relates to jigs having float-
controlled electrical connections for operating the discharge
valve. The principal features of novelty are in the valve
actuating mechanism and in connection with the float, as
defined in the claims. The device is generally applicable to
jigs, but for purposes of illustration is shown applied to a
jig for washing coal in the accompanying drawing, in which
fig. 1 is a vertical section through the jig transverse to the
axis of the valve; fig. 2 is a fragmentary elevation of the
side of the jig showing the valve driving pawl and ratchet,
the rocker arm, and the hold-out device; fig. 3 shows the
rocker, pawl, and hold-out mechanism in front elevation, the
float and switch in partial section, with the electrical connec-
tions in diagram; fig. 4 is a section through the head of the
rocker arm showing the mounting of the spring relief yoke
for the pawl. In the drawings 1 represents the jig tank, 2
the plunger, and 3 the driving mechanism for the plunger, by
which it is moved upward and downward in the usual
manner; 4 is the perforated screen on to which the material to
be treated is fed, and through which the water contained in
the tank 1 is caused to make a succession of upward pulsa-
tions by means of the plunger 2; 5 represents the overflow,
over which the lighter material, in the present case, washed
coal, passes; and 6 is a rotary discharge valve for the heavier
material. The valve 6 consists of a rotary cylindrical bar,
having longitudinal grooves or ports in its periphery. The
valve 6 fits closely between sealing plates 7 and 8, the plate
8 being adjustable to secure a tight sealing of the valve. Thus
when the valve is rotated it carries in its grooves or ports the
heavier solid material passing under the guard plate 9,
together with such water as is mixed therewith, but the valve
does not permit the free outflow of water. The valve 6 is
rotated by a shaft 10, which passes through a stuffing box 11,
and carries a ratchet wheel 12. Journalled on the shaft 10,
and straddling the ratchet wheel 12, is a bifurcated rocker
lever or arm 13, which carries a pawl 14. The pawl 14
engages the teeth on the ratchet wheel 12, and is mounted on
a journal pin or bolt 15, which passes through slots 16 in the
sides of the rocker lever 13, and is fastened in the arms of a
bifurcated yoke 17. The yoke 17 bears against the lower end
of a coil spring 18, whose upper end bears against a stop 19.
The stop 19 is carried by a bolt or rod 20, whose lower end
is fixed in the upper end of the rocker lever 13. The rocker
lever 13 is rocked by means of a connecting rod 21, and a
crank disc 22, which last is driven in any suitable way. The
throw of the rocker lever 13 may be varied by adjusting the
point of connection of the rod 21 in the radial slot 23 formed
in the lever 13. Thus during the operation of the jig the
ratchet wheel 12, and with it the connected valve 6, is inter-
mittently rotated by the rocking of the lever 13, and its con-
nected pawl 14. If the rotation of the valve 6 be arrested by
the clogging of the valve, the pawl 14 will yield, compress-
ing the spring 18, and preventing the breaking of any of the
working parts. During the operation of the jig it is essential
to keep on the screen a bed of slate, which should be of sub-

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stantially constant depth. This slate is the heavier material,
and consequently the material drawn off by the valve 6. In
jigs handling mineral ores, the heavier material is the con-
centrate. To regulate this bed, use is made of a flat which
rests in the material on the jig screen, and whose position is
determined by the depth of the slate bed. This float is used
to operate a switch, which energises or de-energises a solenoid
24, mounted on the rocker lever 13. The armature or
plunger 2.5 of the solenoid has a link connection 26 to the
pawl 14, and the pawl 14 is so counterweighted as to be
easily moved. Thus, when the solenoid 24 is energised, the
pawl 14 is withdrawn from the ratchet 12, while upon the
de-energisation of the solenoid 24, the pawl drops into
co-active relation with the ratchet 12. The float mechanism
is generally illustrated in fig. 1, and in greater detail in fig. 3.
It is mounted in a bracket 27 fastened on the side of the jig
tank 1, and is carried by a tubular frame .28, through which
the connecting wires to the switch pass. The switch
mechanism is mounted in a case 29, and consists of a fixed
contact 30, and a pivoted contact arm 31, which has a forked
head 32. A float 33 is so mounted as to rest in the material
on the screen, and is guided in vertical movement by a rod
34, which runs in the case 29, and in the extension case 35
mounted thereon. The rod 34 carries at its upper end a
cup 36 to receive shot or similar weighting material, so as to
adjust the float. The rod 34 carries a flange 37, which works
between the branches of the fork 32 on the pivoted contact
arm 31. When it strikes the upper branch it opens the
switch. When it strikes the lower branch it closes the
switch. The device is commonly constructed with a friction
bearing for the arm 31 to retain it alternately in open and
closed positions, but may be provided with a double-acting
spring mechanism, such as is used in ouick opening switches
to cause a sudden opening and closing of the switch. The
contacts 30 and 31 are connected to wires 38 and 39, which
pass through, the tubular frame, and complete a circuit
through the solenoid 24, and some source of electrical current’.

here indicated as a generator 40, and a storage battery 41.
Where a large number of jigs are used, they may all be con-
nected to a single source of current. It will be observed that
the rise of the float 33 above a certain limit opens the control
switch and allows the pawl 14 to fall to operative position,
so that the valve 6 is actuated to reduce the bed of slate on
the screen. The operation of the valve 6 will be stopped as
soon as the depth of this bed has fallen to the lower limit.
The range of movement of the float may be varied by varying
the spacing of the branches of the fork 32, and the minimum
depth by adjusting the frame 28 in the bracket 27. The
movement of the jigged material across the screen is trans-
verse to the line of movement of the float, and might tend in
some cases to cause the rod 34 to bind in its guides. To
prevent this, a V-shaped shield 42 is hung from the case 29,
and preserves a small bed of material at rest in which the
float may work. (Eight claims.)

1415 (1915). Improvements in Single Rope or Chain
Grabs. S. H. Priestman, and R. Wright, both of
Holderness Foundry, Hull. — Relates to improvements in
single-chain grabs of the type wherein a gallery or the like
is necessary to enable the grab head to be suspended there-
from, whilst the lower shaft of the grab is released and
allowed to fall thereby opening the grab. Fig. 1 is a side
elevation partly in vertical section, the grab being shown in
its open condition. Fig. 2 is a part view, in side elevation,
corresponding to fig. 1, and showing in the closed condition
of the grab the portions of the apparatus to which the inven-
tion relates. To enable the grab to be lifted from its lower
shaft a, and without closing the grab, bearings of the upper
shaft b and lower shaft a are maintained

at their full distance from one another by
means of duplicate toggle links c, each pair
of which is locked to the other pair by means
of a hook d pivoted on the central joint
c1 of one of the toggle links. In engag-
ing, the hook d works automatically. For
disengaging and ' allowing the toggle links
c to fold and the top and bottom shafts of
the grab to approach one another, the hock
d is connected to the grab head e, the fall
of the mushroom f serving to lift the hook.
Under certain conditions of working —■ for
example, where the surface of the material
to be grabbed is unusually uneven—the grab
may ground upon the apex of a mound, so
that the weight is supported upon the
lower shaft or sheave casing a1, instead of

upon the , lips of the shells, the closing of the
grab being thereby interfered with or prevented. In order to
overcome this difficulty, there is provided, by means of the
clearance k, for a certain degree of vertical movement of the
lower shaft a, with its sheave or sheaves, in relation to their

casing, so that in the event of the condition mentioned
supervening, by slackening the rope, the lower shaft is per-
mitted to make a slight downward movement, a further
slight straightening of the toggle links c takes place, and
any resistance to the release of the pivoted hook d is
removed. Alternative designs are also described and illus-
trated. (Six claims.)

4079 (1915). Improvements in Means for. Collectively
Actuating and Controlling Alternating-Current Motors. J.
L. Routin, of 2, Rue Olchanski, Paris.—Relates to combina-
tions of alternating current motors, and means for collectively
actuating and controlling the same, each of the motors having
(in addition to a commutator) a plurality of slip rings sever-
ally connected to different points of the rotor winding, and
the slip rings of the several motors being connected to each
other in pairs, as in specification No. 735/1913. It consists
in using stators each having a coil short circuited upon itself
or otherwise disposed for neutralising the armature induction,
and an exciting winding not in series with the armature, fed
at constant pressure out of phase with the voltage supplied to
the rotor winding. It also includes the use of resistances in
the leads to the commutator brushes, and the use of a two-

phase alternator in combination with a phase transformer
for feeding the stators and rotors respectively. The drawing
shows an installation comprising two receivers only. Each
receiver comprises the stator of a bi-polar alternating-current
commutator motor, having coils 1, 2 and 3, 4 arranged at an
angle of 90 degs. to one another, and a rotor 5 wound like
the armature of a continuous current machine. The brushes

6, 7, which bear on the commutator, are aligned with the
axis of the coil 3, 4, which is short circuited upon itself; self-
induction of the

armature is thus
reduced to a
very low value.
The rotor also
carries three
rings, 8, 9, 10,
connected to
three equidis-
tant points of
its coil. The
rings of the two
rotors are con-
nected to each
other in pairs.
The terminals of

the two coils 1,

2, are constantly connected in parallel, as also are the
brushes 6, 7, and the contacts which bear on the rings 8, 9,
10. The coils 1, 2, are fed under constant pressure by the
phase winding 11, 12, by a bi-phase alternator. The rotors
are fed by the second phase winding 11—13 of the said alter-
nator. A small phase transformer 14 is arranged, which
allows regulation of the relation of phase of voltage supplied
to the armature brushes 6, 7, with respect to the phase of
the voltage supplied to the field coils 1, 2, so as to reduce the
current consumed by the armature to the minimum. To vary
the value and the direction of the pressure of the feed of
the circuits with respect to the flux, an auto-transformer is
used, comprising an annular iron core 15, a coil 16, 17, a
fixed secondary junction 18, and an adjustable secondary
junction 19, the latter being a brush adjustable on a ring of
insulated segments 20 severally connected by tapping wires to
the coil. The terminals of the coil are connected to the
winding 11—13 of the alternator, and the junctions 18 and 19
are connected to the brushes1 6 and 7. It is advisable to place
two resistances 21, 22, in the feed wires of the rotors, so as
to limit the currents which would tend to pass between the
rotors through the feed wires. These resistances also practi-
cally prevent the production of currents in the short circuits,
provided by the feed wires and the wires connecting the slip
rings, when the two rotors are not in- exactly the same posi-
tion. (Three claims.'

1423 (1915). Improvements in or relating to Centrifugal
Fans. S. L. Whitfield, 10, Dane-street, High Holborn,
London.—Relates to fans of the type in which the fluid is
operated in two stages, and especially to fans of the type
in which the vane wheel is divided by a central disc, and is

disposed in a casing having two
central suction orifices and two
volutes, the fluid passing from
one volute to a chamber and
from the chamber to the suction
orifice of the second volute.
In the invention the volutes
are similar and are arranged
on opposite sides of a median
plane. Fig. 1 is a front view;
and fig. 2 is a horizontal
section; a is the fan casing
having two volute chambers b
and c symmetrically arranged;
d is an annular flange within
the casing; e is a -shaft dis-
posed in bearings f and g;
h is a disc mounted on the
shaft e and having vanes j, j
and k, k. The disc h and
annular flange d practically
separate the volute chamber b
from the volute chamber c.
m is the air inlet to the volute
chamber b, and n is the dis-
charge into the intermediate
chamber o. The air from the
chamber o enters the volute

Fig. 2.

chamber c by the axial inlet p. Oil cups q, q, and ducts
r, r, are provided for lubricating the bearings. In use, when
the disc h and vanes forming the rotor are set in motion the
air is drawn into the volute chamber b by the eye m, and
discharged into the intermediate chamber o, from this
chamber it enters the volute chamber c by the inlet p, and
is discharged through the orifice s. The discharge may be
disposed in any desired position. (One claim.)

1560 (1915). Improvements in Apparatus for Separating
Dust from Air. Thomas Robinson and Son Limited, and

0. J. Robinson, both of Railway Works, Rochdale, Lanca-
shire, and T. J. Stevenson, of the same place.—
Relates to that kind of apparatus which acts by a
rotary motion of the air to separate the dust by centrifugal
force, and consists in an improved arrangement whereby
more complete separation of dust is obtained with relatively
less power. Fig. 1 is a side

view ; fig. 2 an end view;
and fig. 3 a plan; fig. 4 is
a plan, to an enlarged scale,
of the conical body of the
cyclone. Two or more separ-
ators a of the cyclone type
in series are disposed with
an expansion or dust
depositing chamber b be-
tween any two separators,
the outlet c from one
separator leading through
the depositing chamber b to
the inlet d of the next
separator, and we use a
fan driven by pulley e to
each separator to draw the,
air therethrough and force
it into the depositing
chamber b, or to the final

outlet f; g is the inlet to the first separator. Referring to
fig. 4, recessed pockets h are placed round the conical cyclone
body at intervals arranged in an approximately vertical
position, in polygonal bodies .preferably at the angles - as
shown, so that dead air spaces are formed within the recesses
where the dust can more quickly settle. By the use of a
separate fan to each separator less power is required, and
a better separation of dust is obtained than when a single
fan is used to draw air through a series of cyclones. (Two
claims.)

1814 (1915). Improvements in and connected with Pit
Props. V. A. Verner, of Spring House, Calow, Chesterfield,
Derbyshire.—The object of the invention is to construct an
improved taper pit prop which is exceedingly strong and
durable, which will give way slightly under great pressure,
and in which but little wood is employed, which latter may
be readily renewed. Fig. 1 is a longitudinal section; and
fig. 2 is an elevation of the same. The upper port of the
prop consists of a tube, a, made of suitable. metal such as
steel, and closed at its lower end by splitting the tube and
turning the tongues towards the
centre, or by means of a suitable
metal plug ; or the tube may be cast
with a closed end. This tube a is
preferably filled with concrete or other
suitable material, b, and is provided
at the top like other pit props with a
suitable metal cap a1. The tube a
fits within and slides in the upper
part, c, of an outer tubular member
which is cylindrical or formed with
parallel sides at its upper part c, and
is conical or flared outwards at its
lower part, c1. The outer tubular
member is slotted vertically on dia-
metrically opposite sides at its upper
part at c2 to receive a bolt or cotter, d,

which passes through a hole, a2, made through both sides
of the inner metal tube a and through the concrete. This
bolt or cotter d allows the parts to slide with relation to each
other,.but prevents them becoming detached, in manner.well
known. A tapered wooden plug, e, is inserted into the lower
open end, e1, of the outer tubular member, and projects a
short distance into the upper cylindrical part, c, of the same.
The closed end of the inner tube a rests upon the narrow end
of the plug e, -and when the latter is subjected to sufficient
pressure it is crushed down inside the outer tubular member
c, c1, which latter is at liberty to rise as more weight comes
on, thus allowing more of the plug e to be crushed. To
extract the crushed plug e after use, the upper part or cap a1
of the prop is beaten on the floor, which action ejects the
plug e through the conical end of the outer tubular member
c, c1. (Five claims.)

22333 (1914). Improvements in Rope Haulage Clips for
Colliery Corves and the like. J. H. Potter, 229, Abbey&eld-
road, Pitsmoor, Sheffield ; F. C. Moorwood, 46, Whirlowdale-
road, Millhouses, Sheffield; and J. A. Potter, 7, Chatham-’

Ry!	Fig. 2