Apparatuses and Methods for Cutting a Reverse Spot-Face in a Workpiece

A reverse spot-facing tool (100) for cutting a reverse spot-face (R) in a workpiece (W), the workpiece (W) comprising a through hole (H) having a central axis (A), the reverse spot-facing tool (100) comprising:

• a pilot shaft (104);
• a reverse spot-facing cutter (102) configured to be coupled to the pilot shaft (104);
• a stop (132) comprising:
• a first through opening (152) configured to receive the pilot shaft (104), and
• a lock (154) configured to fix the stop (132) along the pilot shaft (104);
• a thrust bearing (126);
• and
• a biasing assembly (109) that generates a first thrust force (F1) and a second thrust force (F2) equal and opposite to the first thrust force (F1) when the reverse spot-facing cutter (102) is cutting the reverse spot-face (R), wherein the biasing assembly (109) comprises:
• a workpiece-engaging member (110) comprising:
• a third end (161) configured to face the workpiece (W),
• a fourth end (163) opposite the third end (161) and configured to face the stop (132),
• a second through opening (112) extending between the third end (161) and the fourth end (163), wherein the second through opening (112) is bounded by a first wall (127), and
• a first abutment surface (116) configured to engage the workpiece (W);
• a stop-engaging member (118) comprising:
• a fifth end (165) configured to face the workpiece (W),
• a sixth end (167) opposite the fifth end (165) and configured to face the stop (132),
• a third through opening (122) extending between the fifth end (165) and the sixth end (167), wherein the third through opening (122) is bounded by a second wall (129), and
• a second abutment surface 169 configured to engage the thrust bearing (126);
• wherein
• the thrust bearing (126) is configured to be positioned between the biasing assembly (109) and the stop (132),
• the workpiece-engaging member (110) and the stop-engaging member (118) are configured to be adjustably interconnected, and
• when the reverse spot-facing cutter (102) is cutting the reverse spot-face (R), the thrust bearing (126) transmits the second thrust force (F2) from the biasing assembly (109) to the stop (132), and the biasing assembly (109) transmits the first thrust force (F1) to the workpiece (W).

A method (200) of cutting a reverse spot-face (R) in a workpiece (W), the workpiece (W) comprising an obverse side (140), a reverse side (142), and a through hole (H) with a central axis (A), the method (200) comprising:

• installing a pilot shaft (104) in the through hole (H), wherein
• a stop (132) is along the pilot shaft (104) on the obverse side (140) of the workpiece (W),
• a biasing assembly (109) is along the pilot shaft (104) between the workpiece (W) and the stop (132), and
• a thrust bearing (126) is between the biasing assembly (109) and the stop (132);
• attaching a reverse spot-facing cutter (102) to the pilot shaft (104) on the reverse side (142) of the workpiece (W);
• biasing the reverse spot-facing cutter (102) against the reverse side (142) of the workpiece (W) with a preload (144) by generating a first thrust force (F1) against the obverse side (140) of the workpiece (W) and a second thrust force (F2) opposite the first thrust force (F1) against the stop (132) by adjusting the biasing assembly (109);
• and
• rotating the reverse spot-facing cutter (102) via the pilot shaft (104).