As standard all mechanical, hydraulic and pneumatic dock levelers have a full platform width x 16” long hinged bridge assembly. This 16” long hinged bridge assembly is the Industry standard and in conjunction with 2- 4 ½” thick dock bumpers provides adequate lip penetration into the majority of truck beds at the loading dock.
18” long hinged lip assemblies are available as an option and provide additional lip penetration with a perfectly aligned trailer or provide safer lip penetration onto the truck trailer bed if the truck trailer is backed in position slightly off square
Optional 20” long hinged lip assemblies are also available and are often used on refrigerated trucks or trailers. The majority of refrigerated trucks and trailers have a “ribbed” floor section front to back containing the coolant and the optional 20” long hinged lip assembly projects far enough onto the truck bed to rest on top of the refrigerated floor section eliminating any bumps during product transfer.
Longer lips reduce the above level range of the dock leveler. If the above level capability for a dock leveler is stated as 12 inches. This is based on the use of a 16” Lip. If the same dock leveler is configured with an optional 20” lip then the above level range changes from 12” to 8”.
Roll Off Stop hinged lip assemblies are available on hydraulic dock levelers. With the dock leveler in the closed stored position the Roll off Stop lip assembly is in the vertical position and acts as an 8” high barrier to prevent the lift truck from accidentally driving / falling off the closed stored dock leveler to the grade below which is typically 4’ lower than the building floor.
Page 4 of the brochure link illustrates a conventional dock leveler lip assembly, Item 1 and brochure link Page 6 illustrates a Roll Off Stop hinged lip assembly. Â https://www.pentalift.com/wp-content/uploads/2021/04/Hydraulic-Dock-Leveler-Brochure.pdf
Lip assemblies are also available tapered in width to suit narrower truck bed widths. The optional tapered lip assembly is the full width of the dock leveler platform at the back and then tapers inward up to 6” per side on the truck bed end of the hinged lip assembly to accommodate a truck bed narrower than the full hinged lip width.  This option is not recommended unless there are special width trucks as it reduces the effective width of the dock leveler. Current trailers are sufficiently wide to accommodate lips that are not tapered.
Hinged lip assemblies are also available with reduced bevel often referred to as reduced lip crown. The majority of dock leveler hinged lip assemblies are designed to suit a wide range of incoming truck heights. The lip assembly is not completely level with the deck plate; with the deck assembly raised and the lip fully extended the hinged lip assembly is slightly downward biased. If a truck arrives at the loading dock higher than the shipping floor this slight downward bias on the hinged lip assembly assures the lip will rest flat on the bed of truck during loading/unloading.  As well through use and over time as the metal fatigues the dock leveler crown reduces.
In most cases the hinged lip assembly spools are self-cleaning however in some applications such as a wash down environment lip grease fittings are available with the option to schedule regular lubrication which will in fact prolong the efficient operation of the loading dock hinged lip assembly.
For additional information on any Pentalift Loading Dock Product please contact the Pentalift Sales Department.