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Counterbalancing mechanism for an edge-of-dock dockboard

  • US 4,665,579 A
  • Filed: 10/28/1985
  • Issued: 05/19/1987
  • Est. Priority Date: 10/28/1985
  • Status: Expired due to Term
First Claim
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1. In combination, a loading dock having a generally vertical front face, a manually operated edge-of-dock dockboard mounted on the loading dock and including a frame, a center plate having an inner end hinged to the frame and having an outer end and an under surface, said center plate being movable from a generally horizontal position wherein said center plate extends outwardly from said front face to a generally vertical position, a lip pivotally connected to the outer end of the center plate and movable between a downwardly hanging pendant position and an extended position where it forms an extension to said center plate, said lip having an under surface, a linkage comprising a first link having one end pivotally connected to the under surface of the center plate at a first pivot and a second link having one end pivotally connected to the under surface of the lip at a second pivot, the opposite ends of said first and second links being connected together at a third pivot, and biasing means interconnecting said frame and said linkage for partially counterbalancing the weight of said center plate and said lip to thereby aid in pivoting the center plate and the lip to the vertical position, said linkage and said biasing means being constructed and arranged so that when the center plate is in the horizontal storage position the force of said biasing means acts to urge the lip toward said pendant position and when the center plate is in the vertical position the force of said biasing means acts to urge the lip to said extended position.

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