Adjustable dockboard

Claim 1

IN AN ADJUSTABLE DOCKBOARD HAVING A STATIONARY MOUNTING STRUCTURC, A RAMP WITH FRONE AND REAR EDGES, MEANS HINGEDLY CONNECTING THE REAR EDGE PORTION OF THE RAMP WITH THE MOUNTING STRUCTURE SO THAT THE RAMP MAY SWING UP AND DOWN ABOUT A HORIZONTAL AXIS, AND MEANS OPERATIVELY CONNECTED WITH THE RAMP TO RAISE THE RAMP, THE IMNPROVEMENT WHICH COMPRISES: A LIP HINGED TO THE FRONT EDGE OF THE RAMP AND SWINGABLE ABOUT ITS HINGE AXIS FROM A PENDENT POSITION HANGING DOWN IN FRONT OF THE RAMP TO A DEFINED OPERATIVE POSITION AT WHICH THE LIP FORM AN EXTENSION OF THE RAMP; LIP LIFTING MEANS CARRIED BY THE RAMP AND OPERABLE UPON ACTUATION THEREOF TO LIFT THE LIP TO A PREDETERMINED POSITION SHORT OF ITS DEFINED OPERATIVE POSITION, SAID LIP LIFTING MEANS BEING BIASED TO AN INOPERATIVE POSITION; MEANS CONNECTED WITH THE LIP LIFTING MEANS AND ACTIVATED BY UPWARD MOTION OF THE RAMP TO ACTUATE THE LIP LIFTING MEANS, SO THAT THE LIP IS AUTOMATICALLY SWUNG TO A POSITION SHORT OF ITS DEFINED POSITION AS THE RAMP IS RAISED; A LIP HOLDER MOUNTED ON THE RAMP AND MOVABLE BETWEEN AN INOPERATIVE POSITION IN WHICH IT DOES NOT INTERFERE WITH THE LIP OCCUPYING ITS PENDENT POSITION, TO AN OPERATIVE POSITION AT WHICH IT SUPPORTS THE LIP IN A LIFTED POSITION SHORT OF ITS DEFINED OPERATIVE POSITION AS LONG AS THE WEIGHT OF THE LIP IS BORNE BY THE LIP HOLDER, THE LIP HOLDER BEING BIASED TO ITS INOPERATIVE POSITION; AND MEANS RESPONSIVE TO ACTUATION OF THE LIP LIFTING MEANS TO EFFECT MOVEMENT OF THE LIP HOLDER TO ITS OPERATIVE POSITION AS THE LIP LIFTING MEANS IS ACTUATED TO LIFT THE LIP, SAID LAST NAMED MEANS BEING RENDERED INEFFECTIVE TO MAINTAIN THE LIP HOLDER IN ITS OPERATIVE LIP SUPPORTING POSITION BY RETURN OF THE LIP LIFTING MEANS TO ITS INOPERATIVE POSITION SO THAT UPON LOWERING OF THE RAMP AND REMOVAL OF THE WEIGHT OF THE LIP ON THE LIP HOLDER AS A RESULT OF THE LIP BEING LIFTED BEYOND SAID POSITION SHORT OF ITS DEFINED OPERATIVE POSITION, THE LIP HOLDER RETURNS TO ITS INOPERATIVE POSITION.