Dock levelers have a component called a lip plate that is used to rest in the bed of a trailer for loading or unloading product.
The lip plate stores pendent on the face of the dock leveler, and is usually activated by the upward momentum of the dock leveler when activated by a pull chain on a mechanical dock leveler. A powered dock leveler generally uses a hydraulic cylinder to raise and drop a lip plate.
On a pull chain style of leveler, the lip plate has a curved arm weldment connected to a chain that, when activated, pulls the weldment arm down causing the lip to push outward. The weight of the lip plate is countered by a lip assist spring.
A dock leveler uses a gas shock or spring to slow the fall of the lip plate onto the bed of a trailer. The standard drop time of a 16" long lip plate is around 10-15 seconds.
Lip plates are generally offered in several lengths, including 16", 18", 20" and 22" long. These vary based on application, dock parameters, and truck type at your dock. The most common is 16" long.
On a powered dock leveler, a hydraulic cylinder is used to activate the lip plate and slow its' descent onto a trailer.
