Key with status indicating device

摘要

The key comprises a head (2) provided with a window which enables showing a portion of the key body. The head which is pivoted on the body is limited to rotate by half a turn in two directions. The key has two grooves (6) each extending over opposite half of the body circumference, and the grooves are terminated by a bore (7) whose depth is greater than that of the groove. Pins (12) are pressed to the bottom of the bores by a spring (13). When the torque applied to the key head increases, the pins leave the bores and the key head rotates through 180 degrees relative to its stem (1). This lets appear the portion opposite the body (4) through the window.