1. Control box assembly (fig. 5-14). The control
box consists of the three-position wiper switch, the
wiper arm heater switch, a light to indicate when the
heater is energized, a variable powerstat for wiper
control, motor and system overload protectors, and a
full-wave bridge rectifier.
2. Drive unit (fig. 5-15). The drive unit consists of
a dc motor and a drive mechanism, which converts the
rotary motion of the drive motor to a back-and-forth
motion necessary for wiper operation.
3. Wiper arm. The wiper arm consists of upper and
lower arms and the wiper blade. The upper arm is a
stainless steel tube containing a 36-watt heating
element. The lower arm is 20 inches long and is bent
and cut during installation to suit the particular
installation. The wiper blade, attached to the lower arm,
Figure 5-15.--Drive unit.
is constructed of neoprene rubber and is used to clean
the window of water during operation.
the 40 to 1 reduction gear ratio, this means that the wiper
blade completes approximately 90 sweeps per minute at
OPERATION
high speed. With the wiper switch in the ON position,
voltage to the motor is variable through the powerstat
Placing the wiper ON/OFF/PARK switch in the ON
from 68 to 115 volts dc. With the switch in the PARK
position completes the circuit from the variable
position, voltage is fixed at 40 volts dc.
powerstat, through the motor protector, to the bridge
Placing the wiper switch in the PARK position also
rectifier. The ac power is rectified and fed to the drive
completes the circuit to the motor. When the switch is
motor through a fuse and a radio frequency filter.
released it springs back to the OFF position. This is
The motor speed (fig. 5-16) is adjusted through the
convenient for placing the wiper blade out of view when
setting of the variable powerstat in the control box. At
the window wiper is not is use.
full-load speed, the motor shaft turns at 3,600rpm. With
MAINTENANCE
Following prescribed preventive maintenance will
keep the window wiper operational for extended
periods. Refer to NAVSEA S9625-AF-MMA-010 for
procedures on adjusting the wiper blade alignment, the
travel, and the contact pressure.
SUMMARY
The pendulum window wiper is one of the simplest
pieces of equipment the EM will encounter. Since it is
needed when the weather is at its worst, good
maintenance procedures during good weather periods
will preclude having to work outside in the rain.
ULTRASONIC CLEANING MACHINE
Ultrasonic cleaners can be used to clean most items
that can be submerged in aqueous solutions. Besides
Figure 5-14.--Control box assembly.
cleaning small parts, the cleaner is especially useful for
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