Method of making rotary die racks

A method for making a pair of rotary die racks each of which has a partially circular forming face of less than 180.degree. and which also has a flat mounting surface that faces in the opposite direction as the forming face, the method comprising:

• casting a pair of metal blanks of the die racks;
• securing the pair of cast blanks of the die racks to a rotatable spindle in a side-by-side relationship with the mounting surfaces thereof engaged with the spindle;
• turning the forming faces by rotating the spindle while cutting the blanks to form the partially circular shape of the forming face of each blank at the proper location relative to the mounting surface thereof;
• and subsequently cutting teeth in the forming faces extending parallel to the axis about which the forming face is generated with at least some of the teeth cut to include cut sides and a tip which is formed from the turned face.

A method for making a pair of rotary die racks each of which has a partially circular forming face of less that 180.degree. and which also has a flat mounting surface that faces in the opposite direction as the forming face, the method comprising:

• casting a pair of metal blanks of the die racks;
• securing the metal blanks of the die racks to a rotatable spindle in side-by-side relationship with the mounting surfaces thereof engaged with the spindle;
• turning the forming faces by rotating the spindle while cutting the blanks to form the partially circular shape of the forming face of each blank at the proper location relative to the mounting surface thereof;
• cutting teeth in the forming faces extending parallel to the axis about which the forming face is generated with at least some of the teeth cut to include cut sides and a tip which is formed from the turned face;
• heat treating the die racks after cutting the teeth;
• and finish grinding the teeth after the heat treating.

A method for making a plurality of pairs of rotary dies wherein each die includes a partially circular forming face of less than 180.degree. and also includes a flat mounting surface that faces in the opposite direction as the forming face, the method comprising:

• casting metal blanks of the pairs of die racks;
• securing each pair of blanks to a rotatable spindle in a circumferentially spaced relationship to each other pair of blanks with the blank of each pair located in a side-by-side relationship to the other blank of the pair and having the mounting surface thereof engaged with the spindle;
• turning the forming faces by rotating the spindle while cutting the blanks to form the partially circular shape of the forming face of each die rack at the proper location relative to the mounting surface thereof;
• cutting teeth in each forming face extending parallel to the axis about which the forming face is generated with at least some of the teeth cut to include cut sides and a tip which is formed from the turned face;
• heat treating the die racks;
• mounting the pairs of die racks on a fixture in a side-by-side relationship with the teeth aligned laterally;
• and finish grinding the teeth by passes of a grinding wheel along the complete width of the side-by-side mounted die racks on the fixture.