太鼓革 Drum Leather / Taikogawa

What is Taikogawa in Japanese Katana terminology?

This is a part of the ""Foot Leather"" (Ashikawa: a leather-made ""Obitori"" [belt holder] that threads and secures the ""Tachio"" [sword cord]. It is attached to the ""Ashikanamono"" [foot metal fittings]). It is round like a drum and plays a role in securely fixing the Tachio to the Ashikawa without any slack.