After becoming familiar with the backhoe operation, practice coordinated use of the controls in a safe open area at reduced engine speed. Gradually increase engine speed as the technique is mastered.
Operate backhoe gently and smoothly. Avoid swinging boom into mainframe. Sudden stopping or jerking could result in serious damage to tractor and backhoe.
Strive to develop a smooth digging cycle. Avoid abrupt or jerky movements. This is accomplished by operating two or more controls at the same time and not allowing the cylinders to reach the limit of travel.
Should you become confused during operation, simply let go of the controls. The valve control handles will automatically return to neutral.
START EXCAVATION
Only use dipperstick and bucket during the digging cycle. As the dipperstick moves the bucket through the soil, curl bucket to maintain proper bucket position.
At the end of the pass, or when bucket is full, curl bucket completely, lift bucket from excavation and swing boom to dump site.
To obtain a cleaner trench and avoid material buildup directly in front of backhoe, extend dipperstick and curl bucket completely while starting to lift it out of the exca- vation. This will allow excess material to fall back into the excavation.
Consult local utilities before working. Know location of all underground cables, pipelines, over- head wires, and other hazards in working area and avoid contact.
To start the excavation, position backhoe as shown for maximum breakout force.
Actuate the dipperstick cylinder to start digging. Approximately halfway through digging cycle, start bucket curl while continuing to crowd dipperstick in. Should bucket stall, raise boom slightly.
Do not use down pressure on the boom when starting to dig, as this will lift the machine and move it out of alignment with the work.
Figure 3. Starting Position
FILL BUCKET
Control bucket attitude throughout digging cycle to keep teeth parallel to bottom of excavation. This will provide best penetration angle and minimize dragging and scraping bucket through the ground.
Penetration depth is determined by soil condition and type.
Figure 4. Fill Bucket
DUMP AND RETURN CYCLE
Keep the
When bucket is empty, dipperstick and bucket are in position to resume digging upon return to the excava- tion.
TRENCHING AND EXCAVATING
Refer to Figure 5.
Trenching is the most basic backhoe digging operation. Other operations are variations of this basic function.
To maintain a level trench bottom, set bucket at proper approach angle and while crowding
When handle is placed in the float position, pressure on both sides of boom cylinder is released.
Digging near center of swing so material may be dumped on either side will produce good results. Never dig near stabilizers.
Continue the trench by moving machine along trench centerline away from existing excavation. Move machine approximately
14 Operation | MAN0306 (Rev. 5/23/2008) |
|
|
