FRIDEN STW - Page 7

6-15-50
FRIDEN
CALCULATING
MACHINE
CO.,
INC.
Paye
7
HOW
THE
MACHINE
WORKS
MODEL STW
SELECTING KEYS-
ACOMILATOR DIAL
A.ROTO-FLOW
DRIVE:
The
principle
of
the
Roto-Flow
Drive
in
the
Friden
Calculating
Ma-
chine
is
that
all
the
main
rotating
parts
in
the
machine
revolve
in
ONE
DIRECTION
at
alltimes,
whether
the
operation
be
Addition,
Subtraction
or
Shifting
the
Carriage
to
Right
or
Left.
This
prin-
ciple
of
Drive
goes
tar
to
simplify
the
Calculat-
ing
Mechanism
and
especially
the
Transfer
Mech-
anism,
Since
the
rotating
parts
of
the
machine
always
revolve
in
one
direction,
only
one
set
of
Transfer
Gears
and
Levers
is
necessary.
In
the
process
of
switching
from
Addition
to
Subtrac-
tion,
only
the
Accumulator
Dials
are
reversed.
This
action
is
accomplished
through
the
action
ofthe
Addand
Subtract
Gear,
which,
in
reality,
is
two
gears
on
one
hub.
The
Product
Dial
Gear
is
located
between
these
two
Gears.
The
Addand
Subtract
Gear
slides
an
the
Add
and
SubtractGear
Shaft.
Thus,
when
the
front
part
of
this
Gear
en-
gages
the
Product
Dial
Gear,
the
result
is
AD-
DITION:
and
when
the
Rear
part
engages.
the
re-
sult
is
SUBTRACTION.
The
Add
and
Subtract
Gear
always
rotates
in
the
same
direction,
but
the
Accumulator
Dial
Gear
will
rotate
in
either
direction,
depending
upon
whether
it
is
in
mesh
with
the
Frant
Gear
or
Rear
Gear,
FRIDEN
SERVICE
doesn't
COST
the
customer
anything
compared
to
the
DIVIDENDS
it
PAYS