Teac FD-55 Series, Maintenance Manual

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(5) Head load mechanism or CSS mechanism
The head load mechanism is used for models with head load solenoid and
the CSS mechanism is used for double sided CSS model without head load
solenoid. Neither of these mechanisms are used for single sided CSS
model.
The head load mechanism functions to make the head in contact with the
disk when only required so as to reduce disk and magnetic head wear.
This mechanism is constructed with head load solenoid , arm lifter, etc.
For a single sided FDD, the head pad attached to the pad arm of the. head
carriage is depressed against the SIDE 1 of the disk with appropriate
pressure and the disk is held with head and head pad. For a double
sided FDD, the SIDE 1 head is depressed with appropriate pressure
instead of the head pad, as well as the single sided FDD.
In the CSS model, the magnetic head is always in contact with a disk
as far as the disk is installed. In order to elongate the disk and
head lives, it is required to make the disk rotate only when it is
necessary. The CSS mechanism (double sided) is constructed with a CSS
Ass * y which is. designed to protect the contact of SIDE 0 and SIDE 1
heads when the front lever is closed if a disk is not installed. For
the purpose of protecting the head beeing cought and damaged by the
head window edge during disk insertion and ejection, the head protector
to lift up the jacket a little is equipped to the CSS Ass'y. The head
protector is also used in the models with head load solenoid.
(6) Head seek mechanism
The head seek mechanism consists mainly of stepping motor with a capstan
(pooly), steel belt (band), guide shafts, and carriage. The carriage
is connected to the capstan of the stepping motor through the steel belt
core section of the FDD and is specially assembled with high precision.
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