Method and apparatus for producing compound curves corresponding to the intersection between two cylinders

The method of automatically cutting a compound curvature resulting from the intersection of two right angle cylinders, on a rotating workpiece, comprising

• rotating the workpiece at a predetermined speed,
• deflecting through a predetermined distance in timed relation to said predetermined speed a cantilevered beam template of a cross section uniformly diminishing from a thick fixed end to a free thinner end to produce a dynamic curved plane varying from a straight line to a curve corresponding to the curvature of the larger cylinder,
• sensing movement of said beam at a point along said beam,
• controlling the depth position of a tool in response to said sensed movement for cutting a circular line on said rotating workpiece which conforms to the deflection of said beam,
• after rotating the workpiece through one revolution sensing a second position along the length of the beam which conforms to a radially spaced circular plane on the end of the smaller cylinder and indicates a change in depth of cut corresponding to the depth distance along the axis of the smaller cylinder while deflecting the beam in timed relation with rotation of the workpiece, and controlling the depth position of the tool along said second circular plane in conformance with said second position sensed, whereby
• the movement sensed is an undulating plane surface of revolution corresponding to the plane of intersection between two right angle cylinders,
• and repeating the foregoing steps while increasing the depth of cut to gradually cut deeper curves until the exact curvature of intersection of the cylinders is obtained.

A control device for obtaining compound curves having peaks and valleys corresponding to the compound curvature of intersection between two intersecting first and second cylinders on the exposed end surface of the second cylinder while being rotated in a vertical boring machine having a rotating table for supporting the second cylinder, a cutting tool, a powered actuator for positioning the tool, a probe for guiding the powered actuator, and a deflectable template for guiding the probe, the improvement comprising:

• said template comprising a cantilevered beam uniformly diminishing from its fixed end,
• means for continuously deflecting the template to produce a deviation along the template corresponding to a maximum variation of curvature of the exposed surface of the second cylinder which corresponds to the radius of curvature of the larger cylinder along a series of radially spaced circular planes on the second cylinder,
• means for continuously correlating the amount of deflection of the template with movement of the rotary table,
• means for detecting the deflection of the template,
• means responsive to said detecting means for moving the tool toward and away from the second cylinder exposed surface an amount corresponding to the deflection of said template,
• whereby peaks and valleys are cut into said second cylinder exposed surface,
• means for moving the detecting means along the template to measure the deflection at a second point on the template corresponding to a second circular plane radially spaced from said first circular plane, and means for shifting the tool into said second circular plane in response to movement of said detecting means along the template whereby a new set of peaks and valleys are cut in the second cylinder exposed surface of a magnitude corresponding to said template deflections for producing a compound curvature on the exposed surface of the second cylinder which matches the curvature of the first cylinder intersecting at right angles with said second cylinder.