Abstract: A dock leveler includes a pivotally mounted ramp and a lip member pivotally mounted to the distal end of the ramp and moveable between an extended position and a depending position for forming a path between a loading dock and a loadbed of a vehicle. A motor operated linear power screw type actuator is connected to the ramp for moving the ramp to an elevated position and includes an extensible tube member which is engageable with a second tube in telescoped relationship in such a way that the actuator tube may be controlled to be retracted after positioning the ramp to engage the loadbed of a vehicle so that the actuator is not subject to forces exerted by the ramp during oscillatory movement while the vehicle is being loaded or unloaded. In one alternate embodiment the actuator is connected to an intermediate link to allow the pivotal movement of the ramp without exerting damaging forces on the actuator.

Abstract: A dock leveler lip extension mechanism includes a bellcrank pivotally mounted on the leveler ramp and connected to a pull chain, a pushrod for extending the lip and to a counterbalance spring assembly at spaced apart points on the bellcrank. The bellcrank is pivotally mounted on a compensating link connected to a member which is connected to the leveler frame. Upon raising the ramp to the inclined position, the pull chain rotates the bellcrank to extend the lip with the assistance of the counterbalance spring and the compensating link moves to maintain or increase the counterbalance spring force to compensate for changing lip extension force requirements. A lip latch includes a latch link pivotally mounted on a lip moment arm or on the underside of the leveler ramp and supporting a latch member which is yieldably biased into engagement with a latch pin when the lip is moved to the extended position to hold the lip in the extended position until it engages a vehicle loadbed.

Abstract: A self releasing hold-down device for a dock leveler having a ramp mounted for pivotal movement about a hinge axis between a stored position and a working position includes an elongates ratchet bar engageable with a pawl mounted on a body connected to a rod which is anchored at one end to the leveler frame. One end of the rod includes a retainer and release pin member mounted thereon and whose position is adjustable by a nut threadedly engaged with the rod. A coil spring is sleeved over the rod and engageable with the retainer and release pin member. The body includes an elongated tube journalling the coil spring and a portion forming a recess for supporting the pawl. A release actuator is pivotally mounted on the body and is engageable by release pins on the retainer and release pin member in response to forces acting on the ramp to effect momentary release of the hold-down device. A manual release lever is operable, at will, to also effect release of the pawl from the ratchet bar.

Abstract: A dock leveler includes a pivotally mounted ramp and a lip member pivotally mounted to the distal end of the ramp and moveable between an extended position and a depending position for forming a path between a loading dock and a loadbed of a vehicle. A motor operated linear power screw type actuator is connected to the ramp for moving the ramp to an elevated position and includes an extensible tube member which is engageable with a second tube in telescoped relationship in such a way that the actuator tube may be controlled to be retracted after positioning the ramp to engage the loadbed of a vehicle so that the actuator is not subject to forces exerted by the ramp during oscillatory movement while the vehicle is being loaded or unloaded. In one alternate embodiment the actuator is connected to an intermediate link to allow the pivotal movement of the ramp without exerting damaging forces on the actuator.

Abstract: A loading dock leveler adapted for being supported for pivotal movement on a loading dock to provide a pathway between the dock and a vehicle being loaded or unloaded includes a ramp formed of a generally flat plate deck member having a plurality of spaced apart, parallel, channel cross section beams welded to the underside of the deck member and extending between a distal side edge of the deck member and a side edge which is disposed adjacent the loading dock. Plural spaced apart pairs of hinge members are welded to the deck member and to the beams at the distal side edge of the deck member and a truss structure including somewhat V-shaped struts extend between the hinge members and are welded to the hinge members and the deck member to provide a lightweight, rigid and durable support structure for minimizing deflection of the deck member and failure of a hinge connection between the ramp and a dock leveler lip member.