ELECTROMECHANICAL CYLINDER LOCK

Abstract: An electromechanical cylinder lock-key combination comprises a housing having a bore, a core (10) rotatably arranged in the bore and having a key-way (12). A side bar (20) is arranged to block rotation of the core with respect to the housing when in a blocking position. An electronically controllable actuator (30) is provided to prevent movement of the side bar from the blocking position when a key is not present in the lock. A returning means (50) is arranged to mechanically co-operate with the key and the actuator to move said actuator to a blocking position in response to withdrawal of the key from said key-way. This mechanical movement of the actuator ensures that the electronic blocking mechanism is moved to a blocking position in case of power failure.

Description: ELECTROMECHANICAL CYLINDER LOCK FIELD OF INVENTION The present invention relates generally to an electromechanical cylinder lock and, m particular, a cylinder loc< in which a blocking arrangement is mechanically returned to a blocking position by means of key with- BACKGROUND Electromechanical locking devices are known which m- cl-.ce electrically interfaced or controlled release mechanisms for operating a lock cylinder. For example, US patent No 5,839,307 discloses an electromechanical cylinαer locκ whicn includes an outer lock housing and a rotatable core located tnerein which is controlled by dual locking features. A plurality of electromechanical lcc<mg meπcers in the core with grooves formed therein accept a sice bar or portions m a ncn-olocking posi- t er. A magnetic core rotates tne electromechanical loc<ιπg memoers to a desired position relative to the side bar to allow rotation of the barrel. A drawback with this prior art locking device is that πc mechanical returning of the locking members is pro- viced. This means that tne locking members remain in a ncn-blockmg position should the lock be de-energised during operation thereof, thus decreasing the security of the lock. This could be a result of someone removing tne battery in the key powering the blocking mechanism. OBJECTS OF THE INVENTION An GDiect of the present invention is to provide a lock device of tne kind initially mentioned in which the electrically controlled blocking mechanism is automati- cally returned to a blocking position when the key is withdrawn from the lock cylinder. Anotner OD]ect is to provide a lock device, which is more secure than prior art lock devices. SUMMARY OF THE INVENTION T^e invention is baseo on the realisation that tne blocking mecnanism can be provided with means co-operating witn a return mechanism during withdrawal of a key from tne lock. Thus, according to the invention there is provided a loc<-key combination as defined in claim 1. A lock-key combination according to tne invention s more secure than prior art devices m that mechanical returning of the blocking mechanism is ensured during withdrawal of the key from the lock. BRIEF DESCRIPTION OF DRAWINGS The invention is now described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 shows an exploded view of the core of a cylinder lock device according to the invention; Figs. 2a ana 2b are enlarged perspective views of an actuator accordmc to the invention; F g. 3 is an enlarged perspective view of a finger pin co-operating with components shown m figure 1 ; Fig. 4 is a perspective view showing the interaction of tne finger pin shown in fig. 3 and a key; Fig. 5 shows a cross sectional view of the lock device of figure 1 with the blocking mechanism m a non-block- mg position; Fig. β is a view similar to that of figure 5 but wi n tne clocking mechanism in a fully clocking position; F g. 7 s a view similar to tnat of figure 5 but witn a s ce bar in an extenαeα position; Fig. 8 is a view similar to that cf figure 5 but with tne blocking mechanism in a blocking position effected cy means of withdrawal of the key from the lock; Fig. 9 is a cross sectional view of the lock device of figure 1 showing indexing cf the actuator; and Figs. lOa-c are a perspective view, a plan view and a cross sectional view of a second emoodiment, respectively, of a second embodiment of a blocking mecnanism according to the i-ventior . DETAILED DESCRIPTION OF THE INVENTION In the following, a detailed description of preferred embodiments of tne invention will be given. In figure 1, an exploded perspective view of a cylinder core according to the invention, generally designated 10, is snown. The core is arranged to be placed in a bore 4 of a conventional cylinder housing 2 (shown in figures 5- 9 , . Thus, the core has an cuter surface substantially corresponding to the bore of the housing and includes a key-way 12 configured to receive a key as is known in tne art. The core 10 includes a plurality of tumbler pm bores 14 that receive tumbler pins, of which one 16 is shown in figure 1. The manner in which a properly bitted key (not shown in figure 1) engages the tumbler pins and positions them to a shear line to permit the core 10 to be rotated with respect to the housing is known in the art and thus will not be described in more detail herein. Throughout this description, the blocking function of tne tumbler pins 16 will be disregarded, assuming that a correctly bitted key has been inserted into the lock. Thus, when for example it is stated herein that the core s blocked, it is blocked by the electrically controlled blocking mechanism. W tn reference to figures 5-9, the housing 2 includes a cavity 6 in which is positioned a side bar 20 cooperating with the housing either to block or to permit rotation of the core within the housing. The function of a side bar is described for example in the Swedish patent application No 7906022-4, which is incorporated herein by reference. Thus, the wall of the cavity is formed as a camming surface for moving the side bar out of tne cavity upon rotation of the core. As can be seen m figure 6, which shows tne side bar 20 and an actuator 30 (discussed m detail below) in a core rotation blocking position, the side bar is received in the cavity 6 and its inner edge extends beyond the internal surface of the housing bore 4 and engages the housing to prevent the cere from rotation to operate the lock. The blocking mechanism will now be described in detail. Returning to figure 1, the term blocking mechanism will in this description refer to, besides the side bar 20, the elongated actuator 30 with a partly cylindrical en- velope surface and an electric motor 40 with a shaft 46 mechanically coupled to the actuator 30. The actuator is located radially inward of the side bar 20 in a cylindrical actuator bore 32, see figure 5. The actuator 30 ca be rotated by means of the electric motor 40 positioned in the actuator bore 32 and mechanically connected to the actuator 30. In the preferred embodiment, the connection is effected by means cf the motor shaft 46 being shaped like a screwdriver tip, that is, with an end portion with a flat or at least non-circular cross section. The end of the motor shaft 46 is positioned in a corresponding bore 33 in the end surface of the actuator facing the motor, see figure 2a. In that way, the actuator is rotated together with a motor shaft when the motor 40 is ener- gised. In the other end thereof, the actuator 30 is jcurnalied by means of an extending pin 34, see figure 2b, co-operating with a corresponding bore (not shown) in the actuator bore. The motor 40 is energised under control of lock elec- tronics 48 electrically connected to the motor by means of wires, see figure 1. The electronics 48 comprises a custom made micro controller with associated memories, driving circuitry etc. and is powered by a battery lo ¬ cated in a key inserted into the lock. To that end, there is provided a key contact 42 in the form of an electrically conducting metal strip shaped so as to make contact with a contact on the side of the key blade cf the inserted key. Inward of the actuator 30 there is provided a finger pin 50 movable in a direction perpendicular to the centre axis of the cylinder core 10. The finger pin 50 is provided with a cut out portion 52 aligned with the actuator 30, see figure 3, and is spring loaded downward as seen in figures 5-9 by means of a helical spring 54 located above the finger pin 50. With no key inserted, the finger pin rests on the actuator 30, as seer, in figures 6 and 8, thereby securing it against unwanted rotation. However, the finger pin is lifted by the side code 72 of an inserted key 70, as seen in figures 4, 5 and 7, to an upper end position, in which the rotation of the actuator 30 is not affected. Finally, to ensure that the side bar 20 engages the side bar cavity 6 when aligned therewith, a yoke shaped positioning element 60 is provided outside of the actuator 30 but inward of the side bar 20, see also figure 3. The positioning element 60 is spring biased radially outward by means cf springs (net shown) . Thus, with the side bar 20 aligned with the side bar cavity 4, the spring force applied on the positioning element 60 forces the side bar 20 radially outward and into en- gaσement with the walls of the side bar cavity 4. There is also a spring (not shown) provided at the other end of the side bar compared to the positioning element and also functioning to urge the side bar 20 radially outward. The operation of the blocking mechanism including the side bar 20 and the actuator 30 with motor 40 will now be described with reference to figures 5-9. In figure 5, the blocking mechanism is shown in a non- blocking position, i.e., with an inserted key. The side bar 20 is shown out of alignment with the side bar cavity 6 and in a retracted position and the cylinder core 10 is thus free to rotate in the cylinder housing bore. As is seen in the figures, the actuator 30 is not en- tirely cylindrical. Instead, besides a cylindrical envelope surface 38, it is provided with a recess 35 and an essentially flat engagement surface 36, see figures 2a and 2b. In the non-blocking position, the actuator 30 is in the position shown in figure 5. The cut out portion comprising the recess 35 allows the side bar to be retracted within the outer periphery of the core 10 and into the recess 35, thus allowing rotation of the core relative to the housing. The rotation of the actuator 30 to the position shown in figure 5 is effected by means cf the motor 40. When a correctly electronically coded key is inserted into the lock, the electronics 48 verifies that a correct key has been inserted and sends control signals to the motor 40 to rotate the actuator. The normal blocking position of the blocking mechanism will now be described with reference to figure 6. The side bar 20 has now been aligned with the side bar cavity 6 and pushed therein by means of the force exerted by the positioning element 60 and the above mentioned spring (not shown) provided at the ether end of the sice oar. The actuator has then been rotated approximately 180° counter clockwise compared to the position shc * n in figure 5. This means that instead of the recess 35, the cylindrical envelope surface 38 of the ac- tuator now faces the side bar. In that position, the side bar 20 is prevented from being cammed to within the outer periphery of the core 10, i.e., to within the shear line between the core 10 and the housing 2. The rotational movement of the actuator 30 to the position show" in figure 6 is commanded by the electronics 48 whe- the key is withdrawn from the lock key-way 12. This is tne normal operation of the blocking mechanism. Mowever, there are situations m whicn this normal Dloc<ιng operation is disaoled. An example thereof is whe~ the eiectrcnics 48 is de-energised with the key still in tne key-way 12. This could be a result of someone removing the battery in tne key powering the electronics 48 arc tne motor 40 or a power failure in case of a wired lock. In a lock according to the mven- tic, there is provided a mechanical back-up returning of tne normally electronically controlled blocking mecnanism to a blocked position. This emergency returning Λ/ill now be described with reference to figures 7 and 8. In figure 7, the side bar 20 is snown in engagement with the walls of the side car cavity 6. This position is cDtamed when the side bar 20 aligned with the side bar cavity 6 ana, as already stated, the positioning element 60 forces tne siαe bar into engagement with the side bar cavity walls. In that position, the side bar does not impede the rotation of tne actuator 30. When being withdrawn from the key-way 12, the key releases the finger pin 50 and the spring force exerted by the spring 54 forces the finger pin downward against the actuator 30. During displacement, an engagement surface 56 in the cut out portion 52 of the finger pin 50 engages the engagement surface 36 of the actuator, thereby forcing the actuator to rotate counter clockwise approximately 60° to the position shown in figure 8. After this rotation, the envelope surface 38 of the actuator faces the side bar 20, thereby blocking the radially inward movement of the side bar. In the position shown in figure 8, the actuator 30 has not been rotated as far away from the non-blocking position shown in figures 5 and 7 as when in the normal blocking position shown in figure 6. However, the interaction between the engagement surface 36 of the actuator and the engagement surface 56 of the finger pin ensures that the actuator can not accidentally or fraudulently be rotated to a non-blocking position. The rotation of the actuator 30 is also constrained or indexed by means of a protrusion or pin 22 provided on the side bar 20 and a co-operating indexing groove 39 in the envelope surface of the actuator 30, see figure 2a. The operation thereof appears from figure 9, which is a cross-sectional view of the lock in level with the indexing groove of the actuator. The groove 39 runs approximately 180° degrees around the actuator and the protrusion 22 is guided in that groove during rotation of the actuator. This limits the rotation of the actua- tor to within allowed limits and thus ensures reliable rotation of the actuator. A second embodiment of a key and lock combination according to the invention will now be described with reference to figures lOa-c. In figure 10a there is shown an actuator 30' of essentially the same shape as the actuator 30 described above with reference to the first embodiment. However, the actuator shown in figure 10a s provided with longitudinal grooves 37 along essentially the entire envelope surface 38' thereof. Tne grooves 37 constitute means co-operating with at least one step 24 provided on the side bar 20' . The function of the grooves 37 and the step 24 will now be described w th reference to figure 10c, which is a cross sectional view of the actuator 30' and the side bar 20' taken along the lines A-A, see figure 10b. In tne position shown in figure 5, i.e., with the side oar in the side bar cavity 6, the step 24 does not impede the rotation of the actuator 30' . However, if someone is trying to rotate the core, e.g. trying to fraudulently open the lock, the side bar 20' is cammed out of tne cavity, thereby pressing against the actuator 30' . If the actuator is rotated while the core is rotated, the step 24 of the side bar 20' will engage the first groove 37 encountered and be seated therein, thereby preventing further rotation of the actuator 30' . The provision of the step 24 and the grooves 37 increases the security of the lock, making it even harder to effect a fraudulent movement of the actuator from a blocking to a non-blocking position. Preferred embodiments of a key and lock combination accordinα to the invention have been described. The person skilled in the art realises that these could be varied within the scope given by the appended claims. Thus, a motor has been shown powered by a battery provided in the key. It could also be powered by a battery provided in the lock or by an external power source connected to the lock by means of wires. The actuator has been shown with a specific shape. It is realised that it could have any suitable shape as long as it moves from a non-blocking position (figure 5) to a blocking position (figure 8) under mechanical control when the key is withdrawn from the lock. Although only one finger pin has been shown in the figures, there can be mere than one finger pin interacting with an inserted key and the actuator. This finger pin has been shown movable essentially perpendicularly to the axis of the lock cylinder. It is realised that this pin can be movable in other directions as long as the interaction between the pin and the key and the actuator, respectively, is provided in a functioning way. The finger pin has been shown interacting with a side code of the key. The finger pin can also interact with other portions of the key, such as a groove provided on the side of the key blade. It could for example be provided in the form cf a guided pin. REFERENCE NUMERALS Housing Bore Side bar cavity Cere Key-way Tumbler pin bores Tumbler pin , 20' Side bar Indexing protrusion Step , 30' Actuator Actuator bore Driving bore Journalling pin Recess Engagement surface Grooves , 38' Envelope surface Indexing groove Motor Key contact Motor shaft Electronics Finger pin Cut out portion Helical spring Engagement surface Positioning element Key Side code

Claims: CLAIMS 1. An electromechanical cylinder lock-key combination, comprising - a housing (2) having a bore; - a core (10) rotatably arranged in said bore and having a key-way (12) for receiving a key (70) ; a side bar (20) co-operating between the housing (2) and the core (10) and being movable between - a first position, in which rotation of the core Λf tn respect to tne nousmg is permitted, and a second position, in which rotation of the core with respect to the housing is blocked; and an electronically controllable actuator (30) pro- vided in said core (10) and being rotatable between a first position (Fig. 5), m which the movement of sa d sice bar (20) to said first side bar position is permitted; and a second position (Fig. 6), in wnich movement of said side bar (20) to said first side bar position is blocked; characteri sed by - a returning means (50) mechanically co-operating with said key (70) and said actuator (30) and moving said actuator from said first position to a third position (Fig. 8) in response to withdrawal of the key from said key-way (12), said third position blocking movement of said side bar (20) to said first side bar position. 2. Combination according to claim 1, wherein said returning means (50) is a pin, preferably a finger pin. 3. Combination according to claim 1 or 2, wherein said returning means (50) is movable in a direction essentially perpendicular to the centre axis of the core (10) . 4. Combination according to any of claims 1-3, wherein said returning means (50) is biased in a direction towards the actuator (30), preferably by means of a spring (54), preferably a helical spring. 5. Combination according to any of claims 1-4, wnerein said returning means (50) is co-operating with a side code (72) of the key (70). 6. Combination according to any of claims 1-5, wherein said actuator is provided with an essentially cylindrical envelope surface (38) with a recess (35) and a first engagement surface (36), said first engage- ment surface being arranged to co-operate with a second engagement surface (56) provided on the returning means (50 so as to move the actuator from said first position (Fig. 5) to said third position (Fig. 8) in response to withdrawal of the key (70) from said key-way (12). 7. Combination according to claim 6, wherein said second engagement surface is provided in a cut-out por ¬ tion of said returning means (50) . 8. Combination according to claim 7, wherein said first and second engagement surfaces (36,56) are essentially flat and, with said actuator in the first position, have a mutual angle of about 60°. 9. Combination according to any of claims 1-8, wherein said actuator (30) is provided with an indexing groove co-operating with a protrusion (22) provided on said side bar (20) so as to limit the rotation of said actuator . 10. Combination according to claim 9, wherein said groove is running about 180° around said actuator in a direction parallel to the direction of rotation of said actuator. 11. Combination according to any of claims 1-10, wherein said actuator is journalled in a first end thereof by means of a motor shaft (48) co-operating with a bore provided in said first end and in a second end thereof by means of a protruding pin (34). 12. Combination according to any of claims 1-11, wherein said actuator (30') is provided with longitudinal grooves (37) arranged to co-operate with a step (24) provided on the side bar (20') in order to prevent rotation of the actuator (30') during rotation of the core (10) .

Inventors: MAGNUSSON BJOERN, WALLDEN LARS, MAGNUSSON, BJOERN, WALLDEN, LARS
Applicants: ASSA AB, MAGNUSSON BJOERN, WALLDEN LARS, MAGNUSSON, BJOERN, WALLDEN, LARS
Application year: 2000
Main classification: E05B47
IPC codes: E05B27, E05B47