Counterbalance for mechanical dock leveler
AssigneeUnited Dominion Industries, Inc.
InventorJames C. Alexander
Life of this patent
Estimating the term…
Abstract
A dock leveler has a deck pivotally mounted to a frame. A counterbalance mechanism uses a pair of pivoting links connected together at a common point with a tension spring that is coupled at the other end to the deck. The links together with the frame and the deck form a four-bar linkage biased by the spring to counterbalance the weight of the deck.
Claims16
A dock leveler comprising:
- a frame mounted to a dock surface, a deck pivotally mounted to said frame, said deck movable between a stored generally horizontally position and an inclined position, a counterbalance mechanism including a first link pivotally secured to said deck and a second link pivotally secured to said frame, ends of said first and second links joined for relative pivoting movement at a common pivot point, a spring coupled at one end to said deck and at another end operably coupled to said common pivot point, said deck having a pin for attachment of said first link and said first link having a mounting hole sized to have width greater than the diameter of the pin, whereby rolling contact occurs between said pin and a surface of said hole said first link pivots, and said frame having a pin for attachment of said second link and said second link having a mounting hole sized to have a width greater than the diameter of the pin, whereby rolling contact occurs between said pin and a surface of said hole said second pin pivots.
A dock leveler comprising a frame mounted in a pit at a dock, a deck having one end pivotally mounted to said frame, said deck movable between a stored generally horizontally position and an inclined position, a lip pivotally connected to another end of said deck, a counterbalance mechanism including a first link pivotally secured to said deck and a second link pivotally secured to said frame, ends of said first and second links joined for relative pivoting movement at a common pivot point, a spring coupled at one end to said deck and at another end operably coupled to said common pivot point, said deck having a pin for attachment of said first link and said first link having a mounting hole sized to have a width greater than the diameter of the pin, whereby rolling contact occurs between said pin and a surface of said hole said first link pivots, and said frame having a pin for attachment of said second link and said second link having a mounting hole sized to have a diameter greater than the diameter of the pin;
- whereby rolling contact occurs between said pin and a surface of said hole said second pin pivots.
Dependencies are inferred from the claim text.