How The Lift Truck Works - UniCarriers FG20 Series Operation & Maintenance Manual

KEEPING THE TRUCK BALANCED
■
Lift trucks are equipped with load handling means
including a mast and forks at its front part. The front
wheels of the truck work as a fulcrum to balance
the center of gravity of the truck and the center of
gravity of the load. The relationship between the
locations of those two centers of gravity is vitally
important for safety.
KNOW THE CENTER OF GRAVITY OF
■
YOUR LOAD
Load's
center
gravity
Distance
Materials of various shapes such as boxes or flat
or cylindrical items may be loaded on the lift truck.
In order to accurately judge the stability of the
truck, it is vitally important for the operator to know
the location of the center of gravity for each type of
load.

HOW THE LIFT TRUCK WORKS?

Weight x distance = moment (constant)
Basic load center
Load center (from fork root) mm
HOW THE CENTER OF GRAVITY
■
SHIFTS
Truck's center of gravity
with high mast raised
Truck's center of gravity
with standard mast raised
The higher the load,
the higher the truck's
center of gravity
Lift truck viewed from front
The stability of the lift truck is determined by the
overall center of gravity, which is the product of the
centers of gravity of the truck and the load. When
the truck is empty, this point is the same as the
center of gravity for the truck, and when it is loaded
it shifts according to the center of gravity of the
load. Since the center of gravity of the load changes
whenever the mast is tilted forward or backward or
the fork is raised or lowered, the overall center of
gravity also changes. The center of gravity is also
governed by the following factors:
Size, weight and shape of the load
•
• Unloading height
• Tilt angle of the fork
• Tire material
• Acceleration, deceleration and turning
Surface condition and gradient of the road
•
Type of attachment
•
1-15
Truck's center of
gravity with truck tilted