Patent GB-1439505-A (GB)
Title: Magnetic locks
IPC: E05B47/00
Filed: 1973-09-21
Abstract: 1439505 Magnetically operated lock GREER HYDRAULICS INC 21 Sept 1973 [21 Sept 1972] 44449/73 Heading E2A A magnetic lock, Fig. 4, comprises a member e.g. core plate 36 carrying permanently magnetised tumblers 68, 68' and disposed between two locking members e.g. plates 38, 38', the tumblers being engageable with the locking members to prevent relative movement between the locking members and the tumbler-carrying member from a locked position, such relative movement being permitted by locating a selectively magnetised key member e.g. pass card 80 to repel or attract tumblers from the locking members as appropriate. As shown, the locking device houses a cartridge 21, Fig. 4, which includes core plate 36 slidable between lock plates 38, 38', a base plate 42 defining with the plate 38 a card-receiving slot 46 for pass card 80 and an outer plate 41, all the plates being secured together to form the cartridge and encased in a housing formed by mounting and cover plates 52, 54. Transversely extending holes 66, 66' in the core 36 carry the tumblers 68, 68', portions of which are receivable in depressions or holes 70, 70' in the plates 38, 38'. Pass card 80 has magnetic "spots" or "areas" 86, 86' which will align with the tumblers to attract or repel the tumblers out of the associated depressions whereby the card may be pushed against the flange 72 on the core 36 to actuate a striker release mechanism. The base plate 42 is of an unmagnetised ferro-magnetic material so that the tumblers are biassed toward the plate 38; the plate 42 may be omitted in which case the plate 52 is made of such material. Forward movement of the cartridge 21 causes a lever 102 to move a spring- loaded pin 103 Fig. 2 which pivots a locking lever 105 to release a lever 109 and striker 30 to enable opening of the door 114, the bolt 112 pivoting the striker out of its path. A spring-loaded latch 126 is normally urged into a slot 132 of the cover plate 54 to prevent relative sliding movement between that plate and the mounting plate 52, the post 130 of the latch having an opening 154 for reception of a tool whereby rotation of the latch is facilitated for release of the cover plate and replacement of the cartridge. In modifications, (a) removable complementary lock plates (237, 237', Fig. 8 not shown) are provided so that the plates may be reversed or replaced whereby a pass card having reversely or differently located spots may be used, (b) the core (436 Fig. 11 not shown) is fixed and the locking plates (438, 438') are slidable, the cartridge (421) being adapted to be "programmed" by a co-operating pair of flexible, non-magnetic shields (475, 475') provided with holes (477, 477') at predetermined locations and in transverse alignment with the holes (466) in the core and the aligned corresponding holes (470, 470') in the lock plates; the plate (438) carries an arm (492) to operate a switch (490) on a cover plate (454), and the shields are reversible or replaceable, and (c) a padlock (Fig. 16 not shown) has a slidable shackle (604) which is secured in the locking position by a spring biassed pin (611) engageable in a notch (613) and withdrawn from the notch by a lever (627) pivoted by a magnetically coded card (680); a spring-loaded latch pin (619) which maintains the shackle in a withdrawn position has a cam surface (625) whereby the edge of the notch cams the pin inwardly when the shackle is forced downwardly.