Dock levelers are essential pieces of loading dock equipment designed to move freight efficiently between the loading dock and a parked, secured truck.
Loading Dock Heights and Dock Leveler Function
Most modern loading docks are designed to be 48 inches high. Incoming truck bed heights, however, commonly vary from 46 inches to 52 inches, measured from the driveway to the top of the truck bed. Trailers transporting ocean containers can reach heights of up to 60 inches.
Dock levelers function as an adjustable-height ramp, allowing them to accommodate these height differences and permit smooth freight flow between the loading dock and the truck bed.
Dock Leveler Lip Position and Operation
When a dock leveler is in the closed, stored position, the hinged lip assembly is vertical. During operation, the deck assembly raises and the hinged lip assembly extends to an angle that is slightly lower than level with the dock leveler platform.
What Is Dock Leveler Lip Crown?
Dock leveler lip crown is the slight downward angle of the extended lip relative to the dock leveler deck.
As the dock leveler lowers, this downward-angled lip rests on the truck bed, allowing consistent contact between the lip tip and the truck bed surface.
Dock leveler lip crown is the slight downward angle of the dock leveler lip that allows the lip to rest properly on the truck bed and maintain smooth load transfer.
Why Lip Crown Is Important
Lip crown ensures the lip assembly always lays in a manner that allows the tip of the lip to contact the truck bed, including situations where the truck bed height is higher than the dock height.
Without lip crown, the extended lip would project upward from the truck bed, creating an obstacle or transition point that would interrupt smooth freight flow and increase the risk of impact or load instability.
Effects of Excessive Lip Crown
Excessive lip crown can create a noticeable bump as lift trucks cross from the dock leveler onto the truck bed. This can result in:
- Operator discomfort
- Premature wear on lift trucks
- Shifting or unstable loads
In applications where the dock height and truck bed height are consistently the same, dock levelers can be ordered with reduced lip crown.
Standard Lip Crown and Manufacturer Recommendations
The standard lip crown provided by dock leveler manufacturers is suitable for the majority of loading dock applications. Reducing lip crown is not recommended unless there is a clear and well-defined application requirement.
Lip Crown and Long-Term Dock Leveler Use
Over time, repeated loading cycles can gradually reduce lip crown. In some cases, a new dock leveler may appear to have excessive crown; however, accounting for long-term wear, an initially higher level of crown can provide better performance over the service life of the equipment.
Dock Leveler Lip Crown – Key Takeaways
- Lip crown is the downward angle of the dock leveler lip
- It ensures proper contact between the lip and truck bed
- Too much crown can cause bumps and wear
- Standard lip crown suits most applications
- Reduced crown should only be specified when justified
Learn More About Pentalift Dock Levelers
For additional information on dock leveler design, lip crown considerations, or any Pentalift product, please contact the Pentalift Sales Department.