When the dock leveler is in the closed/stored position the hinged lip assembly is vertical tucked in behind the front of the dock leveler frame. When the dock leveler is operated the deck raises and the hinged lip rotates outward to the extended position. In the extended position the lip assembly is not parallel with the deck plate it is positioned just slightly lower than parallel to the deck plate, this is referred to as “lip crown”. Dock levelers service varying heights of incoming vehicles; it is important that the dock leveler is able to service trucks that are higher than the dock height. If the lip did not have a crown (if the lip was parallel with the deck surface) with a truck in position above dock height the tip of the lip would project upwards creating a bump when the lift truck enters the trailer and creating a barrier when the lift truck attempts to exit the trailer. It is very important that the hinged lip rest flat on the truck bed when the truck is above dock height, lip crown achieves this purpose. In some applications the dock height and the truck bed height are consistently at the same level, in this case lip crown is not as important therefore the dock leveler can be ordered with reduced lip crown.
Oct 25, 2019