Apparatus for positioning building board

Claim 1

IN APPARATUS FOR POSITIONING BUILDING BOARD, A DOLLY, A VERTICAL MAST MOUNTED ON THE DOLLY, A TELESCOPING EXTENSION SLIDABLY MOUNTED FOR VERTICAL MOVEMENT IN SAID MAST, MEANS CARRIED BY THE MAST FOR RAISING AND LOWERING THE TELESCOPING EXTENSION, A SUBSTANTIALLY RECTANGULAR FRAMEWORK FORMING A FIRST BOARD SUPPORTING MEANS AND PIVOTALLY MOUNTED WITH RESPECT TO SAID TELESCOPING EXTENSION AND CARRIED AT THE UPPER END THEREOF FOR MOVEMENT BETWEEN A SUBSTANTIALLY VERTICAL POSITION AND A SUBSTANTIALLY HORIZONTAL POSITION, A SECOND BUILDING BOARD SUPPORTING MEANS HAVING AN ARM PIVOTALLY CONNECTED TO THE TELESCOPING EXTENSION AT A POINT SPACED FROM THE AXIS ON WHICH THE FRAMEWORK IS PIVOTALLY MOUNTED, COOPERATIVE ENGAGING MEANS CARRIED BY THE FRAMEWORK AND THE SECOND BOARD SUPPORTING MEANS SO THAT THE FRAMEWORK AS THE FRAMEWORK MEANS IS CARRIED WITH THE FRAMEWORK AS THE FRAMEWORK IS MOVED FROM A SUBSTANTIALLY VERTICAL POSITION TO A SUBSTANTIALLY HORIZONTAL POSITION TO THEREBY SUPPORT THE BOARD UNTIL THE WEIGHT OF THE BOARD IS TRANSFERED TO THE FRAMEWORK, THE COOPERATIVE MEANS BEING FORMED SO THAT IT AUTOMATICALLY RELEASES AT A POINT BEFORE THE FRAMEWORK REACHES A HORIZONTAL POSITION, AND LATCH MEANS FOR RETAINING SAID FRAMEWORK IN A SUBSTANTIALLY HORIZONTAL POSITION.