Grinding control methods and apparatus

The method of restoring the face of a grinding wheel which has deteriorated from the desired shape, said method comprising

• rotating the wheel and feeding the wheel face into relative rubbing contact with the operative surface of a truing element, said surface conforming to the desired shape for the wheel face, the hardness of the truing element material being equal to or greater than the hardness of the grit material of the wheel but not so hard that attritious type wear of the truing element does not perceptibly occur, and
• said method being characterized by and including
• conjointly establishing the relative surface speed of said rubbing contact and relative infeed rate of said element and wheel to make the ratio W'/TE' greater than 1.0 where W' and TE' are the volume per unit time rates of removal of materials from the wheel and element.

The method of restoring the face of a grinding wheel which has deteriorated from the desired shape, said method comprising

• rotating the wheel and feeding the wheel face into relative rubbing contact with the operative surface of a truing element, said surface conforming to the desired shape for the wheel face, the truing element material being so vastly harder than the grit material of the wheel that attritious type wear of the truing element does not perceptibly occur,
• said method being characterized by and including
• conjointly establishing the relative surface speed of said rubbing contact and relative infeed rate of said element and wheel to promote grit and bond fracturing of the abrasive grits in the wheel as contrasted with attrition wearing and flatting of the points and corners of those grits, said relative surface speed for this purpose being made less than 3000 feed per minute but greater than zero.

The method of grinding a workpiece which lacks structural rigidity sufficient to withstand, without deleterious deflection, substantial forces imposed thereon by a grinding wheel, said method comprising

• (a) relatively feeding the workpiece and a rotationally driven grinding wheel into relative rubbing contact to create grinding action, and said method being characterized by
• (b) while said procedure (a) is in progress, relatively feeding the operative surface of a truing element, made of material less hard than the grit material of said wheel, into relative rubbing contact with the face of the wheel, and
• (c) conjointly establishing the relative surface speed and relative feed rate of said last-named rubbing contact to make the ratio W'/TE' greater than 1.0, where W' and TE' are the volume per unit time rates of removal of materials from said wheel and element, respectively.

The method of grinding a workpiece which lacks structural rigidity sufficient to withstand, without deleterious deflection, substantial forces imposed thereon by a grinding wheel, said method comprising

• (a) relatively feeding the workpiece and a rotationally driven grinding wheel into relative rubbing contact to create grinding action, and said method being characterized by
• (b) while said procedure (a) is in progress, relatively feeding the operative surface of a truing element, made of a material having a hardness equal to or greater than the hardness of the grit material of said wheel but not so hard that attritious type wear of the truing element does not perceptibly occur, into relative rubbing contact with the face of the wheel, and
• (c) conjointly establishing the relative surface speed and relative feed rate of said last-named rubbing contact to make the ratio W'/TE' greater than 10.0, where W' and TE' are the volume per unit time rates of removal of materials from said wheel and element, respectively.

The method of grinding a workpiece which lacks structural rigidity sufficient to withstand, without deleterious deflection, substantial forces imposed thereon by a grinding wheel, said method comprising

• (a) relatively feeding the workpiece and a rotationally driven grinding wheel into relative rubbing contact to create grinding action, and said method being characterized by
• (b) while said procedure (a) is in progress, relatively feeding the operative surface of a truing element, made of a meterial so vastly harder than the grit material of said wheel that attritious type wear of the truing element does not perceptibly occur, into relative rubbing contact with the face of the wheel, and
• (c) controlling the relative surface speed S.sub.r of said last-named rubbing contact such that it is below 3000 surface feet per minute.