Operation, Automatic reset feature (arf) – SAF-HOLLAND XL-AR363-02 EDL/ARF Feature User Manual
Page 6

FIGURE 10
Sensor Valve Detail
XL-AR363-02 Rev. D
6
OPERATION
Automatic Reset Feature (ARF)
The Automatic Reset Feature (ARF) is designed to ensure that the
External Dock Lock (EDL) flipper plates are not trapped down while
the trailer is being operated. This is accomplished by the use of two
valves. A pilot valve is used to monitor emergency brake pressure to
determine if the trailer is parked or in motion. A sensor valve is used
to monitor the position of the EDL flipper plates (either up or down)
(FIGURE 10).
FIGURE 11
Primary Height Control Valve Detail
Sensor
Valve
Check Valve
Pilot Valve
Primary Height Control Valve
Emergency
Line
Sensor Valve
Primary Height
Control Valve
Pilot Valve
Check Valve
Link
Flipper Plate
Pressure Protection Valve
Emergency Line
To Actuator
Chamber
To actuator
chamber
Air Reservoir Tank
To air springs
To center port
of sensor valve
To PPV
To pilot
valve
To air springs
FIGURE 12
Automatic Reset Feature
The primary height control valve has full function under two
conditions: (1) parking brakes are engaged or disengaged with flipper
plates up or (2) parking brakes are engaged with flipper plates down. If
however, parking brakes are disengaged with flipper plates
down, the sensor valve will add air directly to the air springs.
After the air springs have sufficient air pressure to raise the flipper
plates up off the load pads, the flipper plates rotate up and out of the
way. This disengages the sensor valve and allows the primary height
control valve to resume full function (FIGURE 12).
NOTE:
For further ARF information contact SAF-HOLLAND
Customer Service at 1-888-396-6501.