Regulator key for use on adjustment regulator of hair spring of timepiece, has visual opening released so as to allow visualization of pin bearers and portion of hair spring inserted between bearers by operator or optical instrument

摘要

The key (1) has pin bearers (2, 3) for limiting a radial run-out of a hair spring (20) inserted between the bearers. A support unit is arranged for adjusting a direction (D1) of the bearers parallel to a pivot axis (D) of a regulator (10) in a mounting position of the key. A visual opening (4) is formed along a direction parallel to the direction of the bearers. An orifice is released so as to allow visualization of the bearers and of a portion of the hair spring inserted between the bearers at a distance and/or at contact of one of the bearers by an operator or by an optical instrument. An independent claim is also included for an adjusting assembly for a timepiece movement.