Rate of drive
RESTRICTED
It is assumed that the sight is correctly
calibrated.
The student
must remember that the
rate quadrant at the start of any bombing opera-
tion is at
zero or approximately zero.
dent must also remember that the rate quadrant
moves
from zero to maximum value of the tangent
function, and
that the telescope quadrant moves
Trom maximum sighting angle toward zero sighting
angle.
With this in mind
we will set up the rate
of drive as follows. When the rate knob is rotat-
ed clockwise the intermediate gears drive the rate
bevel pinion which drives the rate bevel gear
is attached to the scindle screw with
a retain-
ing pin.
As the rate bevel gear rotates the spin-
dle screw is rotated.
and down oniy as
The
spindle screw moves up
the trail arm
is rotated.
The
roller carriage is threaded and as the spindle
screw
rotates the carriage moves up
or
down
the spindle
screw:.
As the rate knob
rotated
clockwise
the roller carriage moves upward
on
the
spindle screw
thereby moving the roller up
from
the center of the disc.
The spindle screw turns
the spindle gear, thus driving the rate drive gear,
rate
rack
drive pinion, the
rate
rack and
ground
speed drum
dri ye
translation
gear.
The
the
rate rack is
driven
a distance proportional to
actual
range if
trails
set
in
and orooortional
to whole
range if no trail is
set in.
At time of
synchronization the rate
cam
follower or
stud,
riding
in tane rate quadrant
camway,
t-an s-
lates the
rate quadrant and
angular distance oro-
portional
to
the whole range angle,
has
not been
se I
in, or actua:
range angle if
has
been
se t
when we synehronize, the roller is a distance
to whole range from the center of
ine cis.
The
telescope
is driven proport-
0.a •
• ground
speed.
The telescope is driven
a 2 angula: sceed equal to ground speed.
Four
things are
accomplished
the rate
..-o is rotated:
1.
The roller is positioned on the disc.
2. The automatic release points
are posit-
ioned.
3.
Ground
speed in knots is indicated by
ground peed dial.
4.
The actua! range angle--in terms of
function--is indicated by the
rate
tan
in -
dicator.
72