Lip extension and control device for dock levelers

A dock leveler assembly for carrying traffic between a dock and a vehicle parked adjacent to the dock comprising:

• a support frame;
• a ramp pivotally connected to the support frame and having a front edge;
• lifting means operatively connected to the ramp means for moving the ramp between a stored position, a preparatory position, and an operative position;
• a lip pivotally connected to the front edge for pivoting between a pendant position and an extended position for engaging the vehicle;
• and
• a lip extension and control assembly operatively connected to the lip for automatically extending the lip from the pendant position to the extended position in response to the upward rotation of the ramp, and for automatically rotating the lip from the extended position toward the pendant position after the lip is rotated to the extended position while selectively and controllably adjusting the downward rate of rotation of the lip to increase as it approaches the pendant position after the lip is released from the extended position.

A method for extending and controlling a lip used in a dock leveler for carrying traffic between a dock and a vehicle parked adjacent to the dock, the dock leveler having a support frame, a ramp pivotally connected to the support frame and having a front edge, lifting means operatively connected to the ramp for lifting the ramp between inoperative and operative positions, the lip pivotally connected to the front edge for pivoting between a pendant position in the inoperative position and an extended position for engaging the vehicle in the operative position, an extension assembly operatively connected to the lip for extending the lip from the pendant position to the extended position in response to the upward rotation of the ramp, and a pivot controlling assembly operatively connected to the lip for automatically controlling the rate of rotation of the lip;

• the method comprising:
• raising the ramp to the operative position;
• extending the lip to the extended position;
• lowering the ramp and the extended lip to engage the vehicle;
• and
• selectively and controllably adjusting the downward rotation of the lip with said pivot controlling assembly so that the rate of rotation of the lip automatically increases in a programmed manner from the extended position as the lip approaches the pendant position.

A lip extension and control assembly for use in a dock leveler system having a frame for mounting to a loading dock for vehicles, a ramp having a free front portion and a rear portion hingedly attached to the frame, and lifting means for moving the ramp between a stored position, a preparatory position and an operative position for loading and unloading a vehicle, the lip extension and control assembly comprising:

• a lip having a first edge connected to the ramp front portion for movement between a pendant position for the stored ramp position, an extended position for said preparatory ramp position, and an operative position for said operative ramp position for operative engagement with a vehicle;
• an extension assembly operatively connected to the lip for extending the lip to the extended position in response to rotation of the ramp to the preparatory position;
• and
• a pivot controlling assembly operatively connected to the lip to control the initial downward rate of rotation of the lip as the ramp moves from the preparatory position toward the operative position and to selectively control the rotation of the lip at an increased rate thereafter.

A lip extension and control assembly for use in a dock leveler system wherein the dock leveler system is provided with a frame mounted to a loading dock, a ramp having a free front edge and a rear edge pivotally attached to the frame, and lifting means for moving the ramp between a stored position, a preparatory position, and an operative position for loading and unloading a vehicle, and a lip having a first portion pivotally connected to the ramp for pivoting between a pendant position and an extended position and a second portion adapted for engaging the vehicle in the operative position,

• wherein the lip extension and control assembly comprises a lip control assembly operatively connected to the lip for automatically extending the lip from the pendant position to the extended position in response to the upward rotation of the ramp and for automatically rotating the lip from the extended position toward the pendant position after the lip is rotated to the extended position while selectively and controllably increasing the downward rate of rotation of the lip from the extended position to the pendant position after the lip is released from the extended position, and
• wherein the lip control assembly comprises a biasing assembly operatively connected to the lip by a crank such that the moment arm of the biasing assembly on the crank increases as the lip rotates from the pendant position to the extended position.