(19)
(11) EP 0 558 276 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
20.10.1993 Bulletin 1993/42

(43) Date of publication A2:
01.09.1993 Bulletin 1993/35

(21) Application number: 93301328.6

(22) Date of filing: 23.02.1993
(51) International Patent Classification (IPC)5: E05B 11/06, E05B 21/00, C23C 4/12, H05H 1/42
(84) Designated Contracting States:
BE CH DE IT LI SE

(30) Priority: 26.02.1992 GB 9204134

(71) Applicant: CHUBB RESEARCH LIMITED
Sunbury-on-Thames Middlesex TW16 7AR (GB)

(72) Inventor:
  • Johns-Hunt, John
    Dudley, West Midlands DY5 3NL (GB)

(74) Representative: Obee, Robert William 
Group Patents Department Racal Group Services Limited Richmond Court 309 Fleet Road
Fleet Hampshire GU13 8BU
Fleet Hampshire GU13 8BU (GB)


(56) References cited: : 
   
       


    (54) Lever lock


    (57) A high security lever lock includes a device which is operable, in response to the turning in the lock of an incorrect key or the like implement 36 in the bolt retracting direction such as to lift the levers 5 to incorrect positions, to prevent return movement of the implement to the insertion position. The implement thereby becomes trapped in the lock and prevents access for further attempts at manipulation. False notches 9B are provided in some of the levers 5 to permit limited retraction of the bolt 2 with its stump 6 when set in certain incorrect combinations, the limited bolt retraction causing a pin 19A on the bolt to become trapped in the pocket 28 of a spring-loaded plate 27. Return extension of the bolt 5, and consequent release of the implement 36, is thereby prevented.






    Search report