Universal involute checker

Claim 1

AN INVOLUTE CHECKER COMPRISING A BASE, GEAR SUPPORT MEANS ON SAID BASE FOR SUPPORTING A GEAR IN FIXED POSITION DURING A CHECKING OPERATION, GENERATING MECHANISM ON SAID BASE FOR GENERATING INVOLUTES OF DIFFERENT BASE CIRCLES COMPRISING A FIXED MEMBER HAVING AN ARCUATE GENERATING SURFACE OF PREDETERMINED RADIUS, A BAR HAVING A RECTILINEAR SURFACE, TAPES CONNECTED BETWEEN SAID BAR AND MEMBER TO PREVENT SLIPPAGE AS SAID BAR IS ROCKED ABOUT THE ARCUATE SURFACE OF SAID MEMBER, ADJUSTABLE PARALLEL LINKAGE CONSTITUTING AN ADJUSTABLE PANTOGRAPH PIVOTALLY MOUNTED ON SAID BASE ADJACENT SAID BAR, PIVOT MEANS CONNECTING SAID PANTOGRAPH TO SAID BAR AT A POINT THEREON MOVABLE IN A PATH WHICH IS AN INVOLUTE OF A BASE CIRCLE EQUAL IN DIAMETER TO THE DIAMETER OF THE ARCUATE GENERATING SURFACE AS SAID BAR IS ROCKED ABOUT THE AXIS OF SAID FIXED MEMBER, SAID PANTOGRAPH HAVING AMOVABLE SUPPORT, A CONTACT ELEMENT ON SAID SUPPORT NORMALLY MOVABLE THEREWITH IN A PATH WHICH IS AN INVOLUTE OF A BASE CIRCLE WHOSE DIAMETER DEPENDS ON THE RATIO ADJUSTMENT OF SAID PANTOGRAPH, SAID CONTACT ELEMENT BEING MOVABLE RELATIVE TO SAID SUPPORT, MEANS FOR SENSING MOVEMENT OF SAID ELEMENT RELATIVE TO SAID SUPPORT, MEANS FOR RELATIVELY ADJUSTING A GEAR ON SAID GEAR SUPPORT AND SAID GENERATING MECHANISM TO POSITION SAID CONTACT ELEMENT ON A TOOTH SURFACE OF THE GEAR FOR MOVEMENT IN AN INVOLUTE PATH CORRESPONDING TO THE CORRECT INVOLUTE SURFACE OF SUCH TOOTH, AND MEANS FOR ROCKING SAID BAR RELATIVE TO SAID MEMBER AND PIVOTING SAID PANTOGRAPH ON SAID BASE TO MOVE SAID CONTACT ELEMENT IN THE REQUIRED INVOLUTE PATH.