Control knob for rotation of shaft supported in chassis - has screen cover in form of integral plastics piece with bracket locked in chassis

摘要

The round control knob is non-rotatably mounted on a shaft, with reference marks provided on its top side, completely covered by a screen, except for one or several windows in it. The screen is mounted on a bracket parallel to the knob axis. The bracket (97) and the screen (53) are parts of a single plastics unit (99) mounted on the chassis by a snap-action locking device (100) at the bracket end.