Machine for measuring roundness

Claim 1

IN A MACHINE FOR MEASURING THE VARIATIONS IN ROUNDNESS AND CONCENTRICITY OF CYLINDRICAL OR CONICAL SURFACES OF A PART AS WELL AS THEIR SQUARENESS IN RELATION TO AN ANNULAR SURFACE ON SAID PART, A FIRST ELECTRONIC DISPLACEMENT INDICATOR PROVIDED WITH A CONTACT TIP ADAPTED TO CONTACT THE MOVING CYLINDRICAL SURFACE OF A PART TO BE MEASURED, A POLAR COORDINATE CHART RECORDER INCLUDING A ROTARY CHART DISC ADAPTED TO HAVE A RECORDING CHART POSITIONED THEREON AND A RECORDER PEN RESPONSIVE TO THE SIGNAL FROM THE INDICATOR GENERATED BY THE CONTACT OF SUCH TIP WITH SUCH MOVING SURFACE AND ADAPTED TO TRACE A GRAPH OF SUCH CYLINDRICAL SURFACE ON SAID RECORDING CHART, A ROTARY HIGH PRECISION SPINDLE, RADIAL AND AXIAL THRUST ANTI-FRICTION PRECISION BEARINGS SUPPORTING SAID SPINDLE FOR ROTATION ABOUT A FIXED VERTICAL AXIS WHILE PREVENTING AXIAL MOVEMENT OF SAID SPINDLE, MEANS FOR ROTATING SAID SPINDLE ABOUT ITS AXIS, SAID CHART DISC BEING SYNCHRONIZED WITH THE ROTATION OF SAID SPINDLE, A CHUCK CARRIED BY THE SPINDLE AND ARRANGED TO HOLD AND SUPPORT THE PART TO BE MEASURED FOR ROTATION THEREWITH IN FIXED RELATION TO SAID SPINDLE, ADJUSTABLE MEANS SUPPORTING SAID CHUCK IN FIXED RELATION ON SAID SPINDLE FOR ROTATION THEREWITH WHEREBY SAID CHUCK CAN BE ADJUSTED SO THAT AN ANNULAR SURFACE ON THE PART TO BE MEASURED AND HELD BY THE CHUCK WILL BE PERPENDICULAR TO THE SPINDLE AXIS, A SECOND INDICATOR PROVIDED WITH A CONTACT TIP ADAPTED TO CONTACT SUCH ANNULAR SURFACE ON SUCH PART AS SAID SPINDLE ROTATES, A SECOND POLAR COORDINATE CHART RECORDER HAVING A RECORDER PEN RESPONSIVE TO THE SIGNAL FROM SAID SECOND INDICATOR GENERATED BY THE CONTACT OF THE TIP OF SAID SECOND INDICATOR WITH SAID ANNULAR SURFACE AND ADAPTED TO TRACE A GRAPH OF SAID ANNULAR SURFACE ON SAID RECORDING CHART SIMULTANEOUSLY WITH THE RECORDING OF THE GRAPH OF THE CYLINDRICAL SURFACE OF THE PART, SAID MACHINE BEING CHARACTERIZED IN THAT SAID INDICATORS AND THE CONTACT TIPS THEREOF ARE FREE OF THE LOAD OF THE PART TO BE MEASURED AND IN THAT SAID PART IS SUPPORTED BY SAID CHUCK SO AS TO BE ROTATED BY SAID SPINDLE AND AT THE SAME SPEED THEREOF.