Magnetic lock with first and second locking elements coated with a non-magnetic synthetic resin

摘要

The lock includes a first element 1 and a second element 11, the first element includes an annular permanent magnet 2 with a centre bore 3 therethrough, a ferromagnetic disk-like plate 4 which makes contact with a non-attracting side of the magnet, and a ferromagnetic projecting member 5 which extends from the centre of the plate through the bore until it reaches a plane flush with the plane of an attracting side 9 of the magnet. The magnet, ferromagnetic plate and ferromagnetic projecting member are covered with a non-magnetic, synthetic resin 21. The second element is arranged in a similar manner. In use (Fig. 1(b)) the elements attract each other magnetically, as shown by arrows 52a,52b under the interaction of the magnets, which is coupled with the magnetic lines of force through the first and second ferromagnetic projecting members to produce an increased magnetic force which ensures that the elements are coupled securely. The elements cannot slide laterally relative to each other, as shown by arrows 29,30. The projecting members may be extended such that they reach a plane flush with the resin coating (Fig.2(a)). The coating ensures that any matter such as dust, particularly ferromagnetic particles like iron, cannot enter the gap present between an outer wall of the projecting member and an inner wall of the centre bore. Additionally, all of the metal component parts are protected from rust which might occur if water or moisture entered. The lock may be used with bags, and also clothes which require frequent washing or cleaning.