GB573454A - New or improved holding means for doors, gates, windows, shutters, furniture and likedrawers, and other hinged, pivoted, sliding or otherwise movable articles or parts - Google Patents

Abstract

573,454. Fastenings. RICHARDSON, S. Dec. 23, 1943, No. 21541. [Class 44] [Also in Group XXXV] In a door or like holding means including a permanent magnet on the frame or door and another permanent magnet or a contact piece of magnetic material on the other of these members and operable to effect separation of the two magnetic members so as to break the magnetic circuit partially or completely to enable the door to be opened easily, the (or each) magnet is arranged with both poles exposed on one side to attract the other magnetic member and on the other side has a keeper which shunts the magnetic circuit when the latter is broken. A number of magnets, with co-operating magnets or contact pieces, may be used. The reduction of magnetic influence to enable the door to be easily moved may be obtained by displacing one or both co-operating magnetic elements so that they are out of register, or by interposing a diamagnetic substance between them, or by both means, the necessary movements being effected, directly or through mechanism, by a handle on the door ; the parts are preferably biassed to their co-operating position, e.g., by spring, weight, or magnetic means. The magnets are preferably made of heat-treated alloys such as those known under the Registered Trade Marks " Alcomax " and " Ticonal," which permit of a very high flux density. In the arrangement shown, the door-frame carries a magnet 6 in a casing 4 made wholly or partly of magnetic material and making contact with the poles of the magnet to act as a keeper when the door is open ; a non-magnetic insert 8 is placed between the poles of the magnet. The door carries a similar magnet 7, with interpole insert 10, in a similar casing 9 which is slidable in a fixed case 11 by means of a handle 15 to move the magnets out of register (as shown) to enable the door to be opened. A backing spring 13 prevents rattling of the casing 7. Instead of sliding, the magnet 7 may be rotated out of register with the magnet 6. One magnet may be replaced by a contact piece made, at least partly, of ferromagnetic material. It may be of non-magnetic, paramagnetic or diamagnetic material with magnetic facings or inserts, or vice versa, or formed of alternate magnetic and non-magnetic sections fixed together ; the diamagnetic facings or inserts (where provided) may be thin, so that the magnetic influence is maintained to some extent. The two magnets, or magnet and contact piece, may be in actual contact in the co-operating position, or may be separated by a small air-gap or non-ferromagnetic distancepiece ; if they come into contact a pad of rubber or felt may be placed behind one of them, or between them, to absorb shock, or the contact piece itself may be springy. Instead of the magnets being fitted in casings which act as keepers, separate keeper strips may be provided. The invention serves to prevent rattling, and may be used, in addition to or instead of the usual fastening, on windows, drawers, or any other relatively movable articles or parts. A number of modifications in detail are described, some only in the Provisional Specification.