The diamond drill. (Crystal Falls, Iron County, Mich.) 1887-1996, 1891-10-24

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Harrington $
BLOCK SIGMA r closed an iron cylin-
DANGER der boltcd 10 the
croSs-tirs
This is the operating mechanism Of
the switch, he said. Here are the
two small pipes for compressed air
which come down from the tower
feeding from the three-inch supply
pine Air is admitted To this cylinder
by a ~ valve when the operator
throws the lever on the pneumatic ma
chine The AIR forces the piston rod
forward. The extension Of tho piston
roi is attached 20 what Is called the
sliding plate, which, by means OF bell
crank come ctions, throws the switch
points and so makes cross.ovcr,' or
switch from one track 10 the other.
The semaphore is also moved by
compressed air, but It's cylinder valve
is opened and closed by an electro
magnet connected with storage bat
teries and controlled by signal lever
OF the pneumatic machine. When air
is admitted 10 the cylinder the piston
rod Is forced up and the semaphore
blade Is lowered When the air is ex-
hausted the counterpoise on the soma
phore brings IL 10 danger again.
although the operating mechan-
isms Of the switch and signal nre Sepa-
rate, the switch and its signal are far
from being independent OF each other.
by ingenious automatic devices, me.
chanicnl and electrical. IL is made inn
possible for the o1crator 20 know
clear signal uatil after switch Is
moved and securely locked in the
proper position and each signal when
cleared automatically locks the lever
operating IL and prevents It's being
used 10 release conflicting signals or
switches until il has been again placed
completely at danger These auto.
matte devices are called the interlock-
ing mechanism.
Owe the pneumatic machine, in
closed in a glass case, is a miniature
model Of the switching yard showing
every track. switch. frog aud every
movable frog between Taylor street
and the station. Whenevera switch is
moved the model switch moves too. 30
that the operator can tell NJ glance
the position OF affairs in the yard under
his charge
After the old-timcr had satisfied hrs
mechanical curiosity by examining
every switch in the yard. the party
swarmed aboard n switch engine aud
rolled on 10 the main track toward
Robey street To look into the electric
pneumatic block signaling system.
Electrician Ray called attention 10 a
high post on the right side of the track
having two large scmaphorc blades
the upper one red, the lower green.
Tlis j. block signal and the move
ment ~ the scmaphorcs is controlled
entirely and automatically by the en-
CINE, car o. hand car passing over the
rails. a block Is the section OF track
lotwcen two such signals the lengths
OF blocks varying according 10 circum
stances and eNigcncicS The semi
phorcs arc thrown 10 safety or clear
that Is, tho blades then point down az
nm angie Of 90 degrees, by compressed
air. Mike he semaphores on switch
signals. block scmnphorcs stand nor
mally at clear Now, u little electro
magnate operates the waive which adj
mits or exhausts the compressed air
into the cylinder of The mechanism
which moves the scmaphorcs
A current OF electricity is passed
around piece ~ soft iron. giving tho
property OF magnetism 90 he iron only
40 long as the current is on. Now, the
steel rails Of the track within a block
are the conductors which carry the
electric current generated by common
gravity batteries. through the electro
magnet which operates the com
pressed air valve OF tho signal mcchan.
ism The rails are connected with
each other al the splice ars by wire
and. as the rails OF each block are en-
tirely insulated from those adjoining.
each block has its own circuit
AZ the current Is always on. the arma
tcre Of the magnet operating the valve
nolts II open. and the air pressure
keeps tho scmaphorc blades NJ
safety Tut suppose the electric
urrcnt = suddenly switched Oft the
electro magnet. IL loses is magnetism
the urmaturc no longer attracted 90 10
~ dra wn lack by n spring the valve
turns, shutting OF the mir pressure and
the heavy counter weights ON tho
scmaphore causesIt 10 rise 30 u hort on.
tai position and - indicates danger
AZ Toxic japan. n concern employees
an al 81 NOT 80 trut.aH III afsnu. ffs-