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Wells—A Steel Strip Coiler
When the coiler is ready for operation the
driving rollers are running and turning the mandrel
and the flappers are closed.
As the nose of the strip enters the coiler, it is
guided round the mandrel by the 3 rollers and
the flappers. The "steering gear," as the mechanism for opening out the rollers is called, has now
started to move and when the strip has taken
2 or 3 turns the flappers open. The steering
gear must open out at a speed sufficient to keep
the rollers lightly resting on the. strip as the coil
builds up, i.e. fast enough to allow the coil room,
but,slow enough to keep the coil turning. If it
does not open fast enough, then the.coil will seize
on to the mandrel. If it opens too fast, the coil
will stop turning and the rest of the strip will shoot
straight through.
This motion continues until the coil is complete,
when the steering gear stops. Dynamic braking
is applied to the rollers by 25 volts d.c. being
introduced to the stator windings of the motors.
Then the whole coiler moves laterally by means
of the "shifting gear." The coil itself is prevented
from moving with the coiler by a stationary wall.
When the mandrel has been fully extracted, the
coil drops on to a runway and rolls on to a transfer
chair, which places it on to a hook of a conveyor
chain where it is taken to the unloading bank.
When the coil is clear of the coiler, the steering
gear re-starts and completes its cycle of operation,
bringing the rollers back on to the mandrel, and
the rollers re-start. The shifting gear moves the
coiler back into position and the flappers close.
The coiler is now ready for the next strip.
Electrical Control
The electrical control of the coiler is effected
by a cam controller, time relays and changeover
relays.
The cam controller consists of a number of
cam-operated switches turned by a small motor
operating off the variable frequency supply, driving
through a magnetic clutch. Each of the cams is
adjustable, and suitable interlocks are provided
to ensure the regular operation of the sequence
of events just described.
The whole operation is thus entirely automatic
and is giving excellent service.
MISCELLANEA
An Induction Theory of Hypnosis
Plastics in the Radio Industry. By E. G. Couzens,
B.Sc, A.R.CS.', and W. G. Wearmouth,
Ph.D.
(Hulton. Pp. 57. 2s. 6d.)
SIR,
M. M. Frceland may be interested in two
This is one of the "Electronic Engineering"
facts about body currents.
monographs and deals with a subject of conWhen a person is involved in a process of the siderable importance to the electrical engineer of
will, such as, "Shall I for some reason, or shall to-day. The first chapter is devoted to a brief
I not, drink this nasty liquid?" currents flow, discussion on the nature of plastics, showing how
but cease as soon as a decision is reached.
this property is derived from the peculiar arrangeNeural currents have a propagation velocity of ment of the molecules in long chains by the process
about lOm/s.
of polymerization.
The first fact is not out of accord with an
The next chapter deals with the manufacture,
induction theory. The latter is less promising, firstly, of the basic plastic substance and its
since it suggests we are not dealing with the com- manipulation into forms suitable for manufacture
mon phenomena of electricity and magnetism. and then the actual manufacture of the article
Thus the propagation mechanism cannot be the itself. There is, of course, a variety of techniques
simple electromagnetic one of a transmission here, some materials being thermoplastic and
line, for if so the nerve fibres would possess others, such as bakelite, being thermo-setting and
enormous inductance or capacity or both, which actually changing their chemical construction
clearly they do not. The mechanism is un- during the production of the article.
doubtedly chemical and ionic.
A separate chapter is devoted to the later types
Apart from these considerations there are of cellulose plastic, including the styrene and vinyl
others, some highly adverse.
types which'have become so prominent recently.
With circuits of such small inductance and
Chapter IV deals with the physical properties
particularly when the significant frequencies are of a number of thermoplastics in common use
so low one would not expect appreciable induction while Chapter V deals with the manipulation of
effects. Normal neural currents induce no effects the plastics, showing how they can be worked,
in other persons.
cemented together, moulded and laminated. •
Speech is a common and necessary link between
The final chapter deals with the electrical propthe minds of hypnotist and subject in much erties of plastics and a series of appendices prohypnosis. If all hypnosis were an induction vides additional practical data and an extensive
effect this would not be so.
bibliography.
Hypnotic action is usually personally selective.
The book is well illustrated and constitutes a
This asks a lot of magnetic induction. If as an practical and concise review of a most important
onlooker one stood behind or close to the subject subject. Although the title suggests that the book
one would experience nothing.
is applicable mainly to the radio industry, the
Yours sincerely,
rapidly increasing use of plastics throughout electrical engineering makes the book of considerably
J. E. BEST.
wider appeal.
J. R.
London, 5. W.I6
56 —
THE EDITOR,
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