A dockboard to be mounted on the front surface of a loading dock and adapted to bridge the gap between the dock and the bed of a carrier. The dockboard includes a ramp which is composed of a deck plate and an extension lip. The rear edge of the deck plate is hinged to the frame of the dockboard by a series of hinge loops, while the lip is pivotally connected to the forward edge of the deck plate and is adapted to engage the bed of the carrier when the ramp is in the operating position. In the storage position, the deck plate is located in a generally horizontal position and the lip hangs downwardly from the deck plate in a generally vertical pendant position. To move the ramp to the operating position, the deckplate, which is not counter-balanced, is manually pivoted upwardly to a generally vertical position, and a lug that is pivotally connected to the undersurface of the lip engages an abutment on the frame to lock the deckplate in the vertical position. The deck plate is then forced outwardly away from the dock and the linkage between the deck plate, the lip and the frame enables the outer edge of the lip to inscribe a generally curved path in which it initially moves upwardly to clear the bed of the carrier and then downwardly into engagement with the carrier bed. After loading, the carrier merely pulls away from the dock and the ramp will move by gravity to the storage position.
A ramp assembly for connection with a loading dock to bridge the usual gap between the bed of a truck and the loading dock while the truck is being loaded or unloaded at the dock. The ramp assembly includes a pair of hinged load bearing ramp plates to be secured to a metal bar or plate forming a part of the front of the loading dock and adapted to be selectively positioned to provide a load bearing surface between a truck bed and the dock surface. The plates are hinged together and one of the plates is provided with a longitudinal edge hinge secured to an angle member which is welded to the steel plate in the dock. A pair of bump blocks are secured to the dock face at opposite ends of the loading plates. Stop means are secured on the inside faces of the bump blocks to position a first of the ramp plates at a near horizontal position and a spring assembly is connected between the plates and the angle and one of the bump blocks for biasing the plates upwardly to reduce the force required to lift them when positioning them on a loading truck bed.
An improved counterbalancing mechanism for an edge-of-dock dockboard. The dockboard comprises a frame mounted on a loading dock and one end of a center plate is pivotally connected to the frame. A lip is hinged to the opposite end of the center plate and is movable between a downwardly hanging pendant position and an extended position where the lip forms an extension to the center plate. A counterbalancing mechanism includes a first link pivotally connected to the center plate, and a second link pivotally connected to the lip. The opposite ends of the links are connected together, and a counterbalancing mechanism, such as a spring, interconnects the first link and the frame of the dockboard. The linkage is constructed and arranged so that when the center plate is in a horizontal storage position and the lip is pendant, the force of the counterbalancing spring will urge the lip in toward the dock. When the lip is manually elevated, the counterbalancing spring will assist in pivoting the center plate from the horizontal to the vertical position and then assist in pivoting the lip to the vertical extended position. In the operational position of the dockboard, in which the extended lip rests on the bed of the truck, the force of the counterbalancing spring aids in maintaining the lip in the extended position.
A lip extender for use with a loading dock leveler. The lip extender includes a lower link connected at its lower end to the base plate of the leveler and a toggle arm connected at its upper end beneath the lip. The opposite ends of the toggle arm and lower link are pivotally connected together. Upward movement of the hinge connection between the bridge plate and lip moves them both upwardly to a cocked position in which they are supported by the toggle arm and lower link, which pivot into an over-center position. Downward force exerted on the upper part of the bridge plate causes a cam follower carried by the pivotal connection between the toggle arm and lower link to engage a cam surface mounted beneath the bridge plate. The lip is thereby extended simultaneously upwardly and outwardly over the rear edge of a truck disposed adjacent to the dock. When the lip reaches its fully extended position, the toggle arm moves past the center position and allows the lip to drop onto the truck bed.
A vertically stored dockboard. The dockboard includes a frame or supporting structure which is mounted on a loading dock and a rap or deck plate is hinged at its rear edge to the frame and is movable between a generally vertical storage position and a horizontal operating position where the ramp bridges the gap between the loading dock and a truck parked in front of the dock. The ramp is moved upwardly to the vertical storage position by a hydraulic cylinder mechanism and is locked in the storage position by a toggle assembly. As the ramp is moved upwardly to the vertical storage position, the toggle assembly will be automatically moved to an over-center position to lock the ramp in the storage position. The toggle assembly can be released by a manually operated toggle release arm to enable the ramp to fall by gravity to the horizontal storage position.
The invention is incorporated in a dock leveler of the type having a base plate adapted to be attached to a side edge of a dock, a bridge plate having a first edge pivotally coupled to the upper edge of the base plate and a lip plate pivotally coupled to the other edge of the bridge plate. First and second linkages have first ends respectively pivotally coupled together. The other end of the first linkage is pivotally coupled to the under side of the bridge plate. The other end of the second linkage is pivotally coupled to the base plate for pivotal movement about a pivot axis that is fixed relative to the base plate. A catch member has a first end pivotally coupled to the under side of the lip plate and a free end adapted to hang downward therefrom. The catch member has an engaging portion adapted to releasably engage structure of the first linkage when the bridge plate is moved to its rearward position for holding the free end of the lip plate away from and forward of the bridge plate as the bridge plate is moved from its rearward position toward its forward extended position for allowing the lip plate to engage the bed of a vehicle.
