Lock mechanism for drafting table

Claim 1

IN COMBINATION WITH A DRAFTING TABLE INCLUDING A DRAWING BOARD, FIRST AND SECOND RELATIVELY MOVABLE MEMBERS FOR ADJUSTABLY SUPPORTING SAID BOARD, MEANS FOR LOCKING SAID BOARD IN SELECTIVELY ADJUSTED POSITIONS COMPRISING, A ROD ATTACHED TO SAID FIRST MEMBER, BEARING MEANS ON SAID SECOND MEMBER, SHAFT MEANS ROTATABLY MOUNTED IN SAID BEARING MEANS ON SAID SECOND MEMBER FOR ROTATION ABOUT AN AXIS TRANSVERSE TO SAID ROD, A LOCKING BLOCK HAVING AN OPENING LOOSELY RECEIVING SAID ROD AND OPERATIVE WHEN TILTED RELATIVE TO THE ROD TO BIND THEREAGAINST AND LOCK THE ROD AND BLOCK AGAINST RELATIVE MOVEMENT, MEANS MOUNTING SAID LOCKING BLOCK ON SAID SHAFT MEANS IN SUBSTANTIAL ALIGNMENT WITH THE AXIS OF THE SHAFT MEANS FOR TURNING MOVEMENT THEREWITH AND FOR LIMITED MOVEMENT RELATIVE TO THE SHAFT MEANS IN A DIRECTION AXIALLY AND CROSSWISE OF THE SHAFT MEANS TO ACCOMMODATE VARIATIONS IN THE RELATIVE SPACING BETWEEN THE ROD AND SHAFT MEANS AS SAID FIRST AND SECOND MEMBERS MOVE RELATIVE TO EACH OTHER, MEANS YIELDABLY TURNING SAID SHAFT MEANS IN ONE DIRECTION ABOUT ITS AXIS TO NORMALLY TILT THE BLOCK RELATIVE TO THE ROD AND LOCK THE MEMBERS AGAINST RELATIVE MOVEMENT, AND MANUALLY OPERABLE MEANS FOR SELECTIVELY TURNING THE SHAFT MEANS IN THE OPPOSITE DIRECTION TO RELEASE THE ROD.