Reel lock mechanism of tape cassette, and tape cassette

摘要

Each lock portion ( 15 ) has a front portion ( 23 ) including an anchoring pawl ( 24 ) and a back portion ( 25 ) extending in a direction opposite to the front portion. Therefore, when a slider ( 14 ) withdraws, each back portion comes into contact with the inside surface of a back wall ( 10 ) of a cassette shell ( 4 ) and each lock portion rotates in an unlocking direction. A bottom surface ( 109 ) defining each recess between engaging teeth ( 107 ) has a central portion which protrudes in a chevron shape. A corner of each protrusion has tapered surfaces ( 110 ') and ( 110 ''). An anchoring pawl of each lock portion has a flat surface that comes into contact with one inclined surface ( 109 ') of a chevron-shaped portion of any one of the recesses and one tapered surface ( 110 ') of a protrusion disposed behind the adjacent recess.