| 摘要 |
<p>1528920 Permutation locks ENVIRONMENT SECRETARY OF STATE FOR 17 Dec 1975 [17 Dec 1974] 54519/74 Heading E2A Each wheel of a permutation lock comprises a disc having a recess 15, for engagement with a fence which moves with a bolt 9, wherein the opacity of the wheel pack to penetrating electromagnetic radiation, e.g. X- rays, along any line parallel to the axis of rotation of the discs is independent of the circumferential position of any recess. The combined wall thickness of the recess 7 may be the same as the thickness of the disc adjacent to the recess and along a circular path concentric with the disc axis. Where the thickness of the recess surround is less than elsewhere in the disc a further smaller diameter disc carrying a radial projection, aligned with and having the same dimensions as the recess, may be mounted on shaft 5 adjacent the permutation disc.</p> |
