| 摘要 |
<p>A locking key, designed to preserve an indication of the lock-shifting (opening or closing) operation last performed, has a shank with an extension shaft rotatably received in an adjoining head, the relative rotation of the shank and the head being limited to 90 DEG or 180 DEG by a retaining pin in the head coacting with a part-circular recess on the shaft. The pin and the recess also serve to hold the head in a fixed axial position with reference to the shank. A spring-loaded detent in the shaft or elsewhere inside the head serves to index the two key portions in either of their limiting relative positions.</p> |
