| 摘要 |
PURPOSE:To enable the maintenance of a locking state accompanying the motion of the setting substrate and to also simplify the fitting of the locking device by provid ing grooves encircling the periphery of the stem at a desired interval along the thin stem section of a ferromagnetic stem protruded from a ferromagnetic plate and fitting ring springs to the grooves to lock the stem. CONSTITUTION:A locking device A possesses a hole 1a in the direction from a magnetic pole plane (a) of a permanent magnet to another magnetic pole plane (b), and a ferromagnetic plate 2 is jointed onto the plane (a). In a ferromagnetic plate 3 of another locking device B, a hole is open opened through which the thin stem section 6' of a ferromagnetic stem 6 that has also a thick stem section 6'' long enough to midway the hole 1a is inserted. In the locking devices A,B, the thin stem sections 5', 6' of the ferromagnetic stems 5, 6 are inserted through the setting structures (c) and the portions 5'a, 5'b of the sections 5', 6' that protrude from the structures (c) possess some grooves encircling the stems along the longitudinal direction of each stem. By fitting a ring spring 7 to an appropriate groove of each stem, the stems are locked to their individual substrate c and consequently the ferromagnetic plate 3 is attracted to a magnetic pole plane b of the permanent magnet 1 via the bottom plane of the case 4 and the tips of thick stem sections 5'', 6'' of the ferromagnetic stems 5, 6 are attracted each other inside the hole 1a. |
