Dockboard having improved lip lifting mechanism
AssigneeKelley Company, Inc.
InventorThomas Artzberger
Life of this patent
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Abstract
A dockboard having an improved lip lifting mechanism. The dockboard includes a ramp hinged at its rear edge to a loading dock, and the ramp is adapted to be moved from a generally horizontal cross traffic position to an upwardly inclined position by a counterbalancing spring assembly. A lip is hinged to the front edge of the ramp and can be pivoted from a pendant, downwardly hanging, position to a partially extended position just short of its fully extended position by a lip lifting mechanism which is actuated as a consequence of the ramp moving downwardly from the inclined position toward the cross traffic position.
Claims11
A dockboard, comprising a supporting structure, a ramp hinged at its rear edge to the supporting structure and movable between a generally horizontal cross traffic position and an upwardly inclined position, a lip hinged to the forward edge of the ramp and movable between a downwardly hanging pendant position and an outwardly extending position where the lip forms an extension to the ramp, lip lifting means operably connected to the lip and including a first toggle member pivotally connected to the ramp and a second toggle member pivotally connected to the first toggle member, said toggle members being movable from a first unlocked position, wherein said toggle members are disposed at an acute angle with respect to each other, to a second locked position, said second toggle member being operably connected to the lip and disposed to exert to force against the underside of the lip as the toggle members are moved from the unlocked to the locked position to thereby move said lip to a partially extended position short of its fully extended position, and operating means releasibly engageable with the lip lifting means and responsive to downward movement of the ramp from the upwardly inclined position toward the horizontal cross traffic position for actuating said lip lifting means and moving the toggle members from the unlocked to the locked position to thereby move the lip from the pendant position to the partially extended position, initial upward movement of the ramp from the cross traffic position toward said inclined position acting to operably engage said operating means with said lip lifting means and subsequent downward movement of the ramp causing said operating means to operate said lip lifting means to move the lip toward the partially extended position, movement of the lip to the fully extended position as the lip engages the bed of a carrier located in front of the dock acting to remove the weight of the lip from the second toggle member and permit the toggle members to move from the locked position to the unlocked position to thereby permit the lip to return freely to the pendant position when the carrier moves away from the dock.
A dockboard, comprising a supporting structure, a ramp hinged at its rear edge to the supporting structure and movable between a generally horizontal cross traffic position and an upwardly inclined position, a lip hinged to the forward edge of the ramp and movable between a downwardly hanging pendant position and an outwardly extending position where the lip forms an extension to the ramp, lip lifting means operably connected to the lip and including a link member pivotally connected to the ramp and an elongated member pivotally connected to the link member, said elongated member being operably connected to the lip, said link member and elongated member mounted for movement between a first undercenter position wherein said members are disposed at an acute angle with respect to each other, through an on-center position wherein said members are disposed in alignment, to an over-center position wherein said members are disposed at an angle with respect to each other, and a rigid operating member disposed to operably connect the supporting structure with the lip lifting means and responsive to downward movement of the ramp from the upwardly inclined position toward the cross traffic position for actuating said lip lifting means and moving the members from the undercenter position through said on-center position to said over-center position to thereby move the lip from the pendant position to a partially extended position short of a fully extended position, movement of the lip to the fully extended position as the lip engages a carrier located in front of the dock on further downward movement of the ramp acting to remove the weight of the lip from the elongated member and effecting movement of said members from the over-center position to the undercenter position to thereby permit the lip to return freely to the pendant position when the carrier moves away from the dock.
Dependencies are inferred from the claim text.