Electromechanical lock arrangement

Abstract: An electromechanical lock arrangement includes a lock body (1), which is provided with a cylinder lock mechanism (3) having a key channel (17) and a turnable lock cylinder (16) moving a dead bolt (2) between protruding locking and withdrawn releasing positions. An electrically operable latch means (7) for controlling the operation of the dead bolt (2) and a logic unit (8) for controlling said electrically operable latch means (7) is provided. A key unit (4) has a mechanical key member (4a) for operating the cylinder lock mechanism (3) as well as means for supplying electrical power and means for sending a coded electrical signal to said logic unit (8). At the reception of a correct code, the logic unit (8) is arranged to switch current to said electrically operable latch means (7) so that it allows the dead bolt (2) to be moved from its protruding locking position. The supplying of a code and electrical power is accomplished through a conductor (14) in said mechanical key member (4a) and by making use of a first electrically conductive coupling element (18) turnable with the lock cylinder (16) and a second electrically conductive coupling element (19) stationarily installed in the lock body (1).

Description: The invention relates to an electromechanical lock arrangement of the kind referred to in the preamble of claim 1. It is known to make use of different control codes by means of which it can first be checked if a potential user of a lock mechanism has the right to open it and, hence, to obtain access to a locked space. It is known for instance to provide a cylinder lock mechanism with an arrangement which includes electrically operable latch means preventing turning of the lock cylinder until a logic unit controlling the operation of the dead bolt of the lock mechanism has received the correct control code. The key can include both a mechanical key member for operating the lock mechanism and means for sending a coded signal to the logic unit. In addition, depending on the application, the key can also comprise means for supplying electrical power to the lock, whereby no battery or the like power source has to be provided in the lock itself. This is of advantage especially if the lock is included in a device, e.g. an automatic payphone, which does not necessarily have a power source available in its vicinity. The supply of a control code and/or electrical energy can be accomplished in many different ways, for instance optically or by making use of induction, and naturally, also by means of two electric conductors directly connected to each other, which is a more cost-effective solution than the ones mentioned above. However, a problem with the known arrangements is that an operation to supply a code and/or electrical energy takes place either through means located on the surface of the lock or at least in the key channel of the lock close to the key insertion opening, whereby it is exposed to misuse, dirt and possible wear. EP-A-0432392 describes a door lock in which electrical contact is provided between the key and the innermost pin tumblers of the lock. The key is provided with resistances which can be compared with those provided in a coupling circuit in the doorknob. FR-A-2450930 discloses an electromechanical lock in which a conventional mechanical key is used. A plurality of proximity detectors transmit signals when pin tumblers in the lock have been turned from their initial position by the key. One aim of the invention is to provide an improved electromechanical lock arrangement, which is especially suitable for locking money collecting boxes in automatic payphones, parking meters or other money-receiving stand-alone devices. What constitutes the invention is set in the following claim 1. Security and protection is increased by the fact that at the insertion position of the mechanical key member into the key channel, connection from the code supply means and the electrical power supply means through said two coupling elements to the logic unit is disconnected, so that the code supply only takes place after the mechanical key member has been turned through a certain turning angle inside the key channel into a second position. Thereby the cylinder lock mechanism must first be opened with the right key and thereafter turned further until the contact path to the logic unit can be obtained. In a preferred embodiment of the invention the lock mechanism is a cylinder lock with rotatable locking discs known per se, whereby the supply of a control code and electrical power takes place only after the lock cylinder is first released by turning the locking discs with the mechanical key member and thereafter the lock cylinder is turned further relative to the lock housing into a second position. The mechanical key member desirably includes a conductor running along a key shank in the key member to be inserted into the key channel of the cylinder lock mechanism, electrically insulated from the key shank and projecting somewhat from the end of the key shank, and arranged to cooperate with said first electrically conductive coupling element located at the bottom of the lock cylinder. An uncomplicated and advantageous solution is accomplished when the electrically operable latch means is, in its locking position, arranged to directly act on the dead bolt and to prevent movement thereof into its releasing position. In automatic payphones or similar stand-alone applications where a locked volume is required, the lock body can comprise a casing-like cover element, to which the cylinder lock mechanism is fixed and inside of which the dead bolt is movably installed, so that in its locking position the dead bolt is arranged to extend somewhat out from the cover element. With this kind of stand-alone device it is of advantage to provide the key unit with a power source and a control code selecting and supply means. The invention will now be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 shows, in a partly broken-away side view, an electromechanical lock arrangement according to the invention, and Figure 2 shows a front view of the arrangement of Figure 1, partly in section. The lock arrangement illustrated includes a lock body 1 with a reciprocatingly movable dead bolt 2 and a cylinder lock mechanism 3. Movement of the dead bolt 2 between a protruding locking position (shown in full lines in the drawings) and a releasing position where it is withdrawn into the lock body takes place through the cylinder lock mechanism 3 by turning a mechanical key member 4a of a key unit 4 for the lock arrangement in a key channel 17 provided in the cylinder lock mechanism 3. The cylinder lock mechanism 3 can with advantage be a cylinder lock with rotatable locking discs (not shown in the drawings) known per se. As shown, the mechanism includes a lock housing 15 and inside it a turnable lock cylinder 16. For the basic functions of this kind of cylinder lock mechanism reference can be made for instance to US-A-1514318 and US-A-4211097. The lock body 1 includes a code identifying unit 6 with a logic unit 8 and, under the control thereof, an electrical switch 9, which together control the operation of a latch unit 7. The latch unit includes a small electric motor 12, the nominal operating voltage of which is with advantage in the range 1 to 15 volts, and which controls the rotation of a guiding member 11 supported on the shaft of the motor. The guiding member 11 has two rest positions in the first of which it presses steel balls 10a and 10b, serving as bolt elements outwardly into a protruding position, where they engage with stop faces 2a and 2b on the dead bolt and prevent movement of the dead bolt 2 into its releasing position in the lock body. In the second rest position of the guiding member 11 the balls 10a and 10b are allowed to move inwardly into the latch unit 7 so that the dead bolt 2 is free to move into its withdrawn releasing position in the lock body. For more details of the construction and operation of the latch unit 7 reference can be made to WO 89/11577. Naturally, instead of using a rotary electric motor 12 the operation of the latch unit 7 can be accomplished through other means e.g. by using a solenoid coil as a linear electric motor. Especially for automatic payphones or corresponding applications, the key unit 4 includes a power source and a code selecting and supplying means, which in Figure 1 are generally indicated by the reference numeral 5. By means of the code selecting and supplying means, a code corresponding to each automatic payphone can separately be selected and fed into the lock. In this way, for instance, the locks of all the automatic payphones within a certain area can all be given the same mechanical opening combination, and as a consequence all can be operated by means of the same key unit. For feeding a code and electrical power into the lock mechanism 3, a conductor 14 is provided in the mechanical key member 4a of the key unit, this conductor being insulated from the rest of the key by insulators 20a and 20b, the latter of which extends over the entire length of the shank 13 of the mechanical key member. To coact with the conductor 14, the turnable lock cylinder 16 includes an electrically conductive coupling element 18 which turns with the cylinder 16 but is electrically insulated from it and to which the key conductor 14 is coupled when the mechanical key member 4a is fully inserted into a key channel 17 of the lock mechanism. The lock body 1 includes a stationary coupling element 19 which the movable coupling element 18 can make electrical contact with. This coupling of the elements 18, 19 takes place after the cylinder lock mechanism 3 is first opened by means of the key member 4a so that the lock cylinder 16 is released to turn relative to the lock housing 15. Only then can the coupling element 18 be further turned by the mechanical key member 4a to the position where coupling element 18 engages the coupling element 19. After the coupling elements 18 and 19 have been put into contact with each other the supply of the required code and electrical power can be accomplished. The logic unit 8 compares the code to be supplied with the code or codes programmed in the unit in a known way, because for instance every person authorised to collect money from the automatic payphone can have a code of his own. If the code is correct, the logic unit 8 closes the switch 9, to energise the circuit of the latch unit 7 and allow the balls 10a and 10b to move in and release the dead bolt 2 to move into its releasing position when the key 4a is turned further. Correspondingly when the dead bolt 2 is to be moved back into its locking position, the key 4a is turned in the opposite direction, so that at the position where the coupling elements 18 and 19 engage one another and the circuit is switched on, the logic unit 8 reverses the direction of the current so that the electrical motor 12 turns the guiding member 11 in the opposite direction and forces the balls 10a and 10b out into their protruding positions, whereby movement of the dead bolt 2 into its releasing position in the lock body is again prevented. Naturally the key unit 4 can be designed in many different ways. For instance should it be enough, depending on the application, that the key includes a preprogrammed code, no separate code selecting means is needed since the mechanical key member 4a can be combined with the required electronics so as to form a uniform housing which includes a battery as well as a register for memorising the code. The cylinder lock mechanism 3 can with advantage be provided with so-called lightened locking discs (see US-A-3942346) which include an extra recess widening the key channel and which can be utilised so that the conductor 14 together with the key shank 13 suitably fits into the key channel 17. The design of the lock body 1 in each case depends on the application, i.e. the space intended to be releasably secured by the lock arrangement. Therefore the design of the lock body shown in the Figures is to be understood as only one example of many possibilities. For this purpose a part of the structure of a cover element is additionally sketched with dash lines in Figure 1, into which a lock arrangement according to the invention can be installed so that it can be opened after the dead bolt 2 is released. The invention is not limited to the embodiment illustrated since several modifications thereof are feasible within the scope of the following claims.

Claims: An electromechanical lock arrangement including a lock body (1), which is provided with a cylinder lock mechanism (3) having a key channel (17) and a turnable lock cylinder (16), a dead bolt (2) movable between a protruding locking position and a withdrawn releasing position in the lock body (1) by means of the cylinder lock mechanism (3), electrically operable latch means (7) for controlling the operation of the dead bolt (2) and a logic unit (8) for controlling said electrically operable latch means (7); the arrangement further including a key unit (4) having a mechanical key member (4a) for operating the cylinder lock mechanism (3), the logic unit (8), at the reception of a correct code, being arranged to operate said latch means (7) so that it allows said dead bolt (2) to be moved between said locking and releasing positions, electrical contact being accomplished through said mechanical key member (4a) at the inner end of the key channel (17) of the cylinder lock mechanism (3) by making use of a coupling arrangement, which includes a first electrically conductive coupling element (18) turnable with the lock cylinder (16), arranged in electrical contact with the mechanical key member (4a) and being electrically insulated from the cylinder lock mechanism (3), and a second electrically conductive coupling element (19) installed in the lock body (1), electrically insulated from the lock mechanism and connected through the logic unit (8) to said electrically operable latch means (7), characterised in that said key unit (4a) includes means (14) for supplying electrical power and means (5) for sending a coded electrical signal into said logic unit (8) and in that said first coupling element (18) is arranged to be turned into contact with the second coupling element (19) by means of the mechanical key member (4a) for enabling said supply of a code and electrical power. A lock arrangement according to claim 1, characterised in that at the insertion position of the mechanical key member (4a) into the key channel (17) the connection from the code supply means (5) and the electrical power supply means through said coupling elements (18, 19) to the logic unit (8) is disconnected, so that the supply only takes place after the mechanical key member (4a) is turned through a certain turning angle inside the key channel (17) into a second position of the key member (4a). A lock arrangement according to claim 1 or claim 2, characterised in that the cylinder lock mechanism (3) is a cylinder lock with rotatable locking discs known per se, whereby the supply of a code and electrical power takes place only after the lock cylinder (16) is first released by turning the locking discs with the mechanical key member (4a) and thereafter the lock cylinder (16) is turned further relative to a lock housing (15) into a second position. A lock arrangement according to any one of the preceding claims, characterised in that the mechanical key member (4a) includes a conductor (14), extending along a shank (13) of the key member (4a) to be inserted into the key channel (17) of the cylinder lock mechanism (3), electrically insulated from the key shank (13) and having a portion extending beyond the key shank (13), said extending portion of the conductor (14) being arranged to cooperate with said first electrically conductive coupling element (18) located at the bottom of the lock cylinder (16). A lock arrangement according to any one of the preceding claims, characterised in that the electrically operable latch means (7; 10a, 10b) is, in its locking position, arranged to act directly on the dead bolt (2; 2a, 2b) and to prevent movement thereof into its releasing position. A lock arrangement according to any one of the preceding claims, characterised in that the lock body (1) comprises a casing-like cover element, to which the cylinder lock mechanism (3) is fixed and inside of which the dead bolt (2) is movably installed, so that in its locking position it is arranged to project somewhat out from the cover element. A lock arrangement according to any one of the preceding claims, characterised in that the key unit (4) includes a power source and a code selecting and supply means (5). A lock arrangement according to any one of the preceding claims, characterised in that the latch means (7) includes an electromagnetic motor (12). A lock arrangement according to claim 8, characterised in that the motor (12) moves a guiding member (11) between two rest positions. A lock arrangement according to claim 9, characterised in that in one rest position the guiding member (11) holds a ball (10a) where it engages a surface (2a) and blocks movement of the dead bolt (2) and in the other rest position it releases the ball (10a) to move out of the way of the surface (2a).

Inventors: HURSKAINEN OIVA, HURSKAINEN, OIVA
Applicants: ABLOY SECURITY LTD OY, ABLOY SECURITY LTD. OY
Application year: 1993
Main classification: E05B49
IPC codes: G07C9