Lip extender for loading dock levelers

A lip extender for use with a loading dock leveler of the type having a vertically directed base plate, a bridge plate pivotally connected to said base plate and a lip pivotally mounted along its inner edge to the outer edge of the bridge plate, said lip extender comprising a lower link pivotally connected at its lower end to said base plate, a toggle arm pivotally connected at its upper end beneath said lip, the opposite ends of said lower link and toggle arm being constructed and arranged so that upon lifting of said bridge plate, the pivotally connected ends of said lower link and toggle arm move into an over-center locking engagement with each other to hold said bridge plate and lip in an elevated position, and a cam mounted beneath said bridge plate, said cam having a cam surface, a cam follower carried by the pivotal connection between said toggle arm and said lower link, and an elongated heavy duty coil spring disposed adjacent to the lower end of said lower link, one end of said coil spring bearing against said base plate and the other end of said coil spring bearing against the lower end of said lower link to counter-balance the weight of said bridge plate and lip through said lower link and toggle arm.