ELECTROMAGNETIC PADLOCK

TECHNICAL FIELD

The present disclosure relates to the field of electromechanical padlocks operated by electronic keys. More specifically, the present disclosure relates to a padlock arrangement including an electromagnetic padlock, and to a method for providing status of an electromagnetic padlock.

BACKGROUND

Electromechanical padlocks are known in the art and may be used in places where a lock fitting can be locked by a padlock to prevent unauthorized access to e.g. a property, an entrance, or a cabinet. US 2011/0050419 A1 discloses a padlock mechanism and a sensor module that detects a state of the padlock mechanism and in response sends out a signal to a central unit. US 2012/0313752 A1 discloses a padlock using GPS for detecting the location each time a key card is used. US10119303B2 discloses a padlock comprising an RFID transponder in the padlock housing, wherein a RFID reading device is configured to read out the RFID transponder of the padlock. US2015/0292244, discloses a padlock with proximity detection.

However, the use of such electromechanical key locks may be limited due to specific safety and/or security requirements.

SUMMARY OF INVENTION

In the light of the above, it is an object of the present inventive concept to provide a padlock arrangement, and a method for providing status of an electromagnetic padlock, wherein the above-mentioned disadvantages of the prior art are addressed.

According to a first aspect of the inventive concept, there is provided a padlock arrangement for locking a lock fitting, comprising: an electromechanical padlock having a housing, and a handheld unit having at least one magnet, said handheld unit being movably connected to the lock fitting via a connector member and being detachably attached to the housing in a position of use, wherein the padlock further comprises a rotatable lock core for receiving an electronic key and being rotatable by the electronic key between a lock position in which the padlock is locked and an unlock position in which the padlock is unlocked; wherein the padlock further comprises a position detecting device arranged in the housing, the position detecting device comprising at least one magnetic sensor arranged to rotate together with the rotatable core, and the position detecting device being arranged to detect at least the lock position of the rotatable core in response to the magnetic sensor detecting a first magnetic flux from the magnet of the attached handheld unit; wherein the position detection device is arranged to generate verification data in response to detecting said lock position of the core; and wherein the padlock is arranged to transmit said verification data to the electronic key as a verification that the padlock has been locked while the handheld unit was attached to the padlock.

The inventive concept enables a locking solution that can be used with a high level of security in a wide variety of applications. The lock fitting to be locked by the padlock may be a fitting used to hold a door, a gate or any other element closed or inaccessible. The lock fitting may typically comprise a hinged hasp with a slot fitting over staple for receiving a shackle of the padlock. Other types of lock fittings may also be used, such as sliding bolt gate latches. According to the inventive concept, the handheld unit including said at least one magnet is movably connected to the lock fitting. The connection may be a direct connection where the connector member is directly attached to a part of the lock fitting, for example connected to an outer end of a hasp. As an alternative, the connection may be an indirect connection where the connector element is attached to another element, such as door ora wall, adjacent the lock fitting.

An advantage of the inventive concept is that it provides a dual level of security. The verification data transmitted from the padlock to the electronic key not only informs the electronic key of the locked status of the padlock. The verification data also informs the electronic key that the padlock has been locked while the handheld unit is being attached to the padlock. Accordingly, the verification data generated and transmitted to the electronic key represents a verification or acknowledgement to the key that the padlock both has been locked and that it has been locked at the right location adjacent the lock fitting, since the handheld unit is connected to the lock fitting via the connector member. If no verification data is received, an alert or warning may be generated to the user.

A further advantage of the inventive concept is that the padlock is not required to be in its normal vertically hanging position during the key insertion and the key operation. This is especially an advantage where the lock fitting is arranged in a tight space or a space difficult to access for the user. Since the magnet required for the generation of the verification data is comprised in a handheld unit, which in its turn is movably connected to the lock fitting, the padlock may be held in any suitable inclined position different from its final vertically hanging position during the key insertion and locking procedure for easier access to the padlock, while the handheld unit still being attached to the padlock to enable the verification data to be generated and transmitted even when the padlock is held in such an inclined position.

A further advantage of the inventive concept results from the handheld unit being detachably attached to the housing in its position of use. This allows a user to detach the handheld unit from the padlock after having unlocked the padlock in order to temporarily place the padlock at another place, and to reattach the handheld unit to the padlock before subsequently locking the padlock.

A further advantage of the inventive concept is that it allows received verification data to be stored in the electronic key as “positive” confirmation log data. A given electronic key may store log data received from a plurality of padlocks, for subsequent transfer of the log data to a synchronization unit, a cloud service, or the like.

According to the inventive concept, the verified data is generated in response to the core being in its lock position and the first magnetic flux being detected. In preferred embodiments, in order to ensure that the padlock is actually locked when the core is in its lock position, the padlock is preferably designed such that the key may be withdrawn from the padlock only if the padlock is locked. As an alternative, one may also consider padlocks having means for detecting if the shackle is locked or not, to prevent the verification data to be generated unless the padlock is locked. A padlock arrangement according to the inventive concept comprises at least the padlock and the handheld unit attached to the connector member. In some embodiments, one or more electronic keys may also be considered as comprised in the arrangement. In some embodiments, the arrangement may also be considered to comprise the lock fitting, which is to be locked by the padlock and to which the handheld unit is directly or indirectly connected via the connector member.

In some embodiments, the position detecting device is arranged to detect also the unlock position of the rotatable core in response to the magnetic sensor detecting a magnetic flux change from said first magnetic flux; the position detecting device is further arranged to generate unlock data in response to detecting said unlock position; and the padlock is further arranged to transmit said unlock data to the electronic key as an information that the padlock has been unlocked while the handheld unit was attached to the padlock.

In such embodiments, the arrangement is arranged to generate and transmit said unlock data to the electronic key only when the detected magnetic flux change is a change from the first magnetic flux. The detected magnetic flux change may be a change from the first magnetic flux to a second magnetic flux, which is different from the first magnetic flux. The detected flux change may be positive or negative. The detected magnetic flux change may also be a change from the first magnetic flux to a situation where the magnetic sensor does not detect any magnetic flux from the magnet. In such a case, the sensor output from the at least one magnetic sensor may be considered as a digital sensor output. This may be implemented by selecting the strength and the position of the magnet such that the magnetic sensor, when rotated away from the magnet to the unlock position of the core, cannot detect any magnetic flux from the magnet. In any event, since the generation and the transmission of the unlock data requires that the unlocking procedure is initiated while the first magnetic flux is being detected, the unlock data which is transmitted to the electronic key not only informs the electronic key of the unlocked status of the padlock. The unlock data which is transmitted to the electronic key also informs the electronic key that the padlock has been unlocked starting from a locked state with the handheld unit being attached to the padlock. One advantage of sending such unlock data to the electronic key is that such unlock data may be at least temporarily stored in the electronic key until the electronic key subsequently receives said verification data from the padlock, as a receipt or acknowledgement that the padlock has been relocked and at the correct location with the handheld unit correctly attached.

In embodiments according to the above where also unlock data is generated and transmitted, the unlock data may be at least temporarily stored in the electronic key until the electronic key subsequently receives corresponding verification data as a “lock receipt”. Thereby, the arrangement may be designed such that once a padlock has been unlocked while the handheld unit is being attached to the padlock, it is required that the electronic key subsequently receives the corresponding verification data when the padlock is subsequently locked. If no such verification data is subsequently received by an electronic key “waiting” to receive such verification data, it is an indication that either the padlock has still not been locked again, or that the padlock may perhaps have been locked again but without the handheld unit being attached. Thus, as long as a “waiting” key has not received a corresponding verification data, it is an indication that the padlock has still not been locked again at the correct location. For handling situations of such absent, unintended, or incorrect locking, the arrangement may further comprise warning means arranged to initiate a warning operation in response to the electronic key having initially received and stored said unlock data but having not subsequently received said verification data. Such warning means may be arranged to be activated in one or more different ways. In some embodiments, the warning means may activated by detecting movement of an electronic key which has received and stored said unlock data but which has not subsequently received a corresponding verification data. A warning may thus be generated to a user who is carrying the electronic key and moving away from the lock fitting location, if the user has first unlocked the padlock with the handheld unit attached but forgotten to correctly lock the padlock again with the handheld unit attached. As an alternative or an addition, one may use a geofence technology implemented in a handheld communication device (e.g. a mobile phone) receiving status information from the key, to activate the warning means if such an electronic key “waiting” to receive corresponding verification data is moved away from the lock fitting outside a virtual geographic fence or boundary. The warning operation may include one or more warning operations, such as a sound alert and/or a visual alert generated by the electronic key and/or by a mobile phone or a handheld communication device communicating with the electronic key. The warning operation may also include triggering an app in a mobile phone to present a visual alert to a user and instructions to the user to take necessary steps to lock the padlock at the correct location. The warning operation may also include transmitting a corresponding error log data to an operation center or the like.

Furthermore, in embodiments according to the above where also unlock data is generated and transmitted, received unlock data not followed by receipt of a corresponding verification data may be kept stored in the electronic key and/or in the a handheld communication device as error-indicating log data until such error- indicating log data is subsequently transferred to a synchronization unit, to the cloud, or similar.

In some embodiments, the handheld unit is shaped such that, in its position of use, it extends at least partly over a front side of the padlock. In preferred embodiments, the handheld unit may comprise an essentially U shaped attachment member which extends at least partly over the padlock housing. In the position of use of the handheld unit, such a U shaped attachment member may cover at least partly a front surface of the housing, at least partly a rear surface of the housing, and at least partly one of the side surfaces of the housing. The side surfaces of padlocks may have different shapes, such as combinations of one or more rounded and/or angled surfaces. In some embodiment, the handheld unit comprises an attachment member having a shape corresponding to the external shape or contour of the housing.

In some embodiments, to prevent the handheld unit from being unintentionally detached from the padlock, the handheld unit is configured to be resiliently attached to the housing it in the position of use. Such resilient attachment may be implemented by one or more resilient tongues exerting a biasing force on the housing in the position of use. Such resilient attachment may also be implemented by making the overall U shaped attachment member resilient. When such a resilient attachment member is slid or positioned over the padlock housing, rounded, or angled side surfaces of the padlock housing may be used during attachment to expand the resilient attachment member into a biased state.

In some embodiments, the handheld unit may be structured and arranged to be mechanically locked to the padlock in response to locking the padlock. This may be implemented by providing a shackle receiving opening in the handheld unit. Such an opening may arranged such that when the handheld unit has been brought to its position of use on an unlocked padlock, the shackle receiving opening is positioned to receive a free end of a padlock shackle for preventing the handheld unit from being detached from the subsequently locked padlock. In preferred embodiments, such a shackle opening may be combined with the above described U shaped configuration. As an example, the handheld unit may comprise an attachment member which in the position of use covers not only a least partly a front surface, a rear surface, and one of the side surfaces of the housing, but also covers at least partly a top surface of the padlock where the shackle is located. The shackle opening is then provided in the part of the attachment member that at least partly covers the top surface of the padlock.

In some embodiments, the design of the handheld unit is such in relation to the design of the padlock housing that the handheld unit can only be attached in its intended correct position, so that the magnet is correctly positioned.

A further advantage of the inventive concept is that it can be implemented such that the magnetic detection can be performed without any need for undesired intervention in the padlock housing, such as forming openings in the housing for the magnetic detection. In preferred implementations, at least a part of the housing is made from a material allowing magnetic flux from the magnet to be detected by the magnetic sensor through said material. Such material include at least brass and aluminum. The entire housing or just part thereof may be manufactured from such material. For stronger padlocks, a different stronger material such as steel may be used for a major part of the housing, while a different material allowing flux transmission is used at the location of the magnet. The material allowing magnetic flux to be detected is preferably arranged at least in the part of the housing where the magnetic sensor is located in the locked position of the padlock. Such a position may be on the front surface of the housing.

In some embodiments, the connector member comprises a chain, a wire, or another type of elongate flexible or bendable member. Typically, a handheld unit not being attached to a padlock may be hanging close to the lock fitting at a height convenient for the user. In preferred embodiments, the connector member has a length which is sufficient to allow the padlock to be held in a non-vertical spatial position for key operation, while the handheld unit being in its position of use attached to the padlock and while a shackle of the padlock at the same time is in engagement with the lock fitting. This may be an advantage in certain applications and locations where key access to a vertically hanging padlock is difficult or even not possible. The user may then hold the padlock with the handheld unit being attached in an inclined position towards the user for easier key operation.

In some embodiments, said at least one the magnetic sensor comprises a Hall element sensor. A Hall element sensor has the advantage that it generates sensor signals also when the detected magnetic flux non-varying. Thereby, when the core is in its lock position, the magnetic sensor can continuously detect said first magnetic flux from the magnet. As an alternative, the magnetic sensor may also comprise magnetically controllable tongue elements.

In some embodiments, the electromechanical padlock is configured to be powered upon insertion of the electronic key in the key receptacle. To this end, the electronic key comprises a power source and power transmitting means, and the padlock comprises power receiving means.

In some embodiments, the arrangement may comprise a programmable electronic key for storing data required for opening the padlock.

According to a second aspect of the inventive concept, there is provided a method for providing status of an electromechanical padlock, said method comprising:

- removably attaching a handheld unit to a housing of a padlock, said handheld unit comprising at least one magnet and being movably connected via a connector member to a lock fitting to be locked by the padlock;

- while the handheld unit is being attached to the padlock, locking the padlock by turning an electronic key inserted into the padlock;

- in response to the act of turning the electronic key for locking the padlock, rotating a magnetic sensor arranged inside the padlock to a rotational position where a first magnetic flux from the magnet of the attached handheld unit is detected by the magnetic sensor;

- in response to locking the padlock while the handheld unit is in its position of use attached to the padlock and said first magnetic flux being detected, transmitting verification data from the padlock to the electronic key as a verification that the padlock has been locked while the handheld unit was attached to the padlock.

In some embodiments, the method further comprises, before said act of locking the padlock: - in optional order: inserting the electronic key into the padlock while the padlock is locked, and attaching the handheld unit to the padlock;

- while the handheld unit is being attached to the padlock, unlocking the padlock by turning an electronic key inserted into the padlock;

- in response to the act of turning the electronic key to unlock the padlock, rotating the magnetic sensor to detect a change in magnetic flux from said first magnetic flux to a second magnetic flux, or to a zero-magnetic flux;

- in response to said act of unlocking the padlock while the handheld unit is in its position of use attached to the padlock and said change in detected magnetic flux being detected, transmitting unlock data from the padlock to the electronic key as a verification that the padlock has been unlocked is while the handheld unit was attached to the padlock.

BRIEF DESCRIPTION OF THE DRAWINGS

The inventive concept, some non-limiting embodiments, and further advantages of the inventive concept will now be described with reference to the drawings in which:

Figs 1 shows a padlock arrangement according to a first embodiment.

Figs 2A-2I show a sequence of steps for unlocking and locking the padlock arrangement in Fig. 1.

Fig. 3 is a flowchart comprising steps performed in Figs 2A-2I. Fig. 4 shows a system incorporating a padlock arrangement

Figs 5A-5C show a padlock arrangement according to a second embodiment. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The inventive concept will now for the purpose of exemplification be described in more detailed by means of examples and with reference of the accompanying drawings, in which currently preferred embodiments of the invention are shown. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness, and to fully convey the scope of the inventive concept to the skilled addressee.

1 ^st embodiment

Fig. 1 schematically illustrates an electromagnetic padlock arrangement according to a first embodiment. The padlock arrangement comprises an electromechanical padlock 10 and a handheld unit 30. The padlock arrangement is configured to be used together with one or more electronic keys 40 and a lock fitting 50. In this embodiment, the lock fitting 50 comprises a hasp 51 attached to a door 60 and a staple 52. Other types of lock fittings may be used.

The padlock 10 comprises a padlock housing or body 11 , and a U-shaped shackle 12 having a first leg 13 rotatably connected to the housing 11 and a second leg 14 which can be freed from the housing 10 upon unlocking the padlock 10. The padlock housing 11 has a top surface 15 where the shackle 12 is arranged, and an opposite bottom surface 16 presenting an opening 17. The housing 11 further has a front surface 18, an opposite rear surface 19, and two smaller opposite side surfaces 20 and 21 . For purposes to be described below, an essentially V shaped recess 22 is formed in the front surface 18. In this embodiment, the V shaped recess 22 extends from an open end 22b at one of the side surfaces 21 to an inner end 22a located essentially halfway between the two side surfaces 20 and 21 , in line with the opening 17.

The padlock 10 further comprises a lock core 23 which is received in the opening 17 of the housing 11 and which is rotatably arranged within the housing 11 for locking and unlocking the padlock 10. One or more fixing means (not shown) are arranged to prevent the lock core 23 from being disengaged from the housing 11 . The lock core 23 is configured to be rotated by an electronic key 40 to move a lock bolt member (not shown) of the padlock 10. Accordingly, the lock core 23 and the electronic key 40 are arranged to rotate together. The lock bolt member is arranged to interact with the shackle 12 in a known manner for locking and unlocking the padlock 10. The rotational positions of the lock core 23 will be referred to as the lock position in which the padlock 10 is locked, and the unlock position in which the padlock 10 is unlocked. Fig 1 shows the lock core 23 in its lock position with the key handle part being parallel to the front surface 18 of the housing 11. In the lower part of Fig. 1 , the housing 10 and the lock core 23 are shown separated from each other in order to illustrate details of the lock core 23.

The electronic key 40 is used to operate the electromechanical padlock 10. The electromechanical padlock 10 comprises an access control device (not shown) for controlling access of an inserted electronic key 40. In the illustrated embodiment, the electronic key 40 is a programmable key. Before the electronic key 40 can be used, it must be activated by the user. In the illustrated embodiment, key activation is performed by the user pressing an activation button 41 on the electronic key 40. When activated, an LED on the electronic key 40 may give a visual feedback to the user (see Fig. 2A)

The electronic key 40 comprises an energy source (not shown), such as a battery, and an electronic control unit (not shown) powered by the energy source. The electronic key 40 also comprises at least one memory for storing data. As illustrated in Fig. 4, the electronic key 12 can access a cloud based service 120 via a gateway 140 and/or a locally hosted access control system, for transferring authorization data to the electronic key 14 or log information from the electronic key 40 to the access control system via internet 120 and a synchronization unit 130 or via a mobile communication system such as the GSM net and a mobile device, such as a mobile phone 110. The electronic key 40 is able to communicate with the synchronization unit 130 or the mobile device 110. Such communication may comprise one or more of a physical contact, near field communication, such as NFC, and radio communication, such as Bluetooth. The electronic key 40 can store all or at least part of data necessary to access one or more specific electromechanical padlocks 10. The electronic key 40 is not able to unlock electromechanical locks for which it does not have the appropriate authorization data. Locking and unlocking of a padlock 10 using the electronic key 40 is rendered possible only if the electronic key 40 is synchronized appropriately via the synchronization unit or a mobile device. Further, the electronic key 40 is provided with means by which electrical power, data and mechanical effort can be transmitted to the padlock in a known manner. The electromechanical padlock 10 is configured to be powered by and communicate with the electronic key 40 upon the insertion of an activated electronic key 40 in the padlock 10. To this end the electromechanical padlock 10 comprises power receiving means, communication means and an electrical control unit (not shown).

The padlock 11 in Fig. 1 further comprises a position detecting device which includes at least one magnetic sensor 24 arranged to rotate together with the rotatable lock core 23. In the illustrated embodiment, the magnetic sensor 24 is arranged externally on the lock core 23 in a rotational position such that it faces the front side 18 of the housing and the inner end 22 of the recess 22 in the lock position of the lock core 23. The magnetic sensor 24 may also be arranged inside the lock core 23. In the illustrated embodiment, the magnetic sensor 24 has a limited extension in the circumferential direction of the cylindrical lock core 23 such that the magnetic sensor 24 is instead facing towards the side surface 20 of the housing 11 when the lock core 23 is turned to its unlock position. The position detecting device is arranged to detect at least the lock position of the lock core 23 in response to the magnetic sensor 24 detecting a first magnetic flux from an externally attached magnet 31 as will be described below.

In the illustrated embodiment, the magnetic sensor 24 is a Hall element sensor. An advantage of using a Hall element sensor is that it sends signals even when a detected magnetic flux is non-varying. Accordingly, the magnetic sensor 24 will be able to detect magnetic flux from the magnet 31 even when the key is not moving.

Referring to Fig. 1 , the padlock arrangement further comprises a handheld unit 30 having at least one magnet 31 . The handheld unit 30 is movably connected to the lock fitting 50 via a connector member 33 and can be detachably attached to the padlock housing 11. The attached position shown in Fig. 2A will be referred to as the position of use of the handheld unit 30. The handheld unit 30 is intended to be permanently connected to the lock fitting 50 via the connector member 33, which means that the handheld unit 30 is always located close or near the lock fitting 50. This has the advantage that incorrect handling of the padlock 10 may be detected and prevented and corrected, ensuring that the padlock 10 is in the correct location near the lock fitting when locked. As shown in Fig. 2B, the connector member 33 is structured and arranged such that the padlock 10 with the handheld unit 30 being attached thereto can be freely held by the user in a convenient orientation and position for key operation, especially in an orientation different from the normal gravity-based vertical hanging orientation of the padlock 10. Typically, the padlock shackle 12 will be in engagement with the staple 52 while the user is holding the padlock 10 in such an inclined position. For this purpose, the connector member 33 may be a chain, a wire, or any type of elongate flexible/bendable member. The length of the connector member 33 may vary depending on type of lock fitting, available space, etc. The length is preferably selected such that the length on the one hand allows the required maneuverability by the user for key operation, and on the other hand ensures that the handheld unit 30 is sufficiently close to the lock fitting 50. A suitable length may for example be less than 10 cm, less than 15 cm, or less than 20 cm. It may also be possible to use a connector member 30 having variable length with elastic and/or spring properties.

The handheld unit 30 is arranged to be detachably attached to the padlock housing 11. The advantage of having the handheld unit 30 attached to the housing 11 (instead of only held against the housing) is to ensure that the magnet 31 is correctly positioned during locking and unlocking. The attachment may be accomplished in many ways. In the illustrated embodiment, the handheld unit 30 is essentially U shaped and may be manufactured from a metal and/or or a plastic material. The shape is preferably such that, when the handheld unit 30 is in its position of use, the magnet 31 supported by the handheld unit 30 is located on the front side surface of the padlock housing 11 opposite to the lock core 23. As shown in Fig. 2G, the U shaped unit 30 is arranged to be slid over the padlock housing 11 from one side, such that it in its position of use partly covers the front surface 18, the rear surface 19, and the side surface 21 of the housing 11. Two attachment tongues 32 engaging the side surface 20 provides the detachable engagement. Thus, in this embodiment, the handheld unit 30 is resiliently attached to the housing 11 . One end of the connector member 33 is attached to the base of the U, while the other end of the connector member 33 is attached to the outer end of the hasp 51 .

The V shaped recess 22 in the front surface 18 of the housing is optional but serves two purposes. First, the recess 22 functions as a positioning guide during attachment of the handheld unit 30. When the handheld unit 30 is to be attached, the magnet 31 (which projects slightly on the inside of the U shaped member) is received and guided by the recess 22 to its correct location at the inner end 22a of the recess 22. Second, the formation of the recess also has the advantage that less housing material is present between the magnet 31 and the magnetic sensor 24, whereby detection of magnetic flux may be enhanced.

It will be appreciated that the material of the housing at the location of the magnet should preferably be selected such that magnetic flux may be detected through such material. Thereby, forming a through opening in the housing at the magnet location may be avoided. In preferred embodiments, there is thus housing material between the magnet 31 and the magnetic sensor 24. Accordingly, the entire housing 11 or at least part thereof, is preferably made from a material allowing magnetic flux from the magnet 31 to be detected by the magnetic sensor 24 through such material. Such material include at least brass and aluminum. For stronger padlocks, a different stronger material such as steel may be used for a major part of the housing 11 while the housing 11 may comprise a brass pin or the like extending from the front surface 18 to the lock core 23.

The position detecting device of the padlock 10, including the magnetic sensor 24, is arranged to detect at least the lock position of the rotatable core 23 in response to the magnetic sensor 24 detecting a first magnetic flux from the magnet 31 of the attached handheld unit 30. In response to detecting said lock position of the lock core 23 in combination with said first magnetic flux, the position detection device generates verification data. The padlock 10 is arranged to transmit the verification data to the inserted electronic key as a verification that the padlock 11 has been locked while the handheld unit 30 was attached to the padlock 10. The verification data thus represents a verification that the padlock 10 has been locked and is in the correct location near the lock fitting 50. In the following, this locked state of the padlock 10 will be referred to as a “verified locked state”.

In preferred embodiments, the inventive padlock arrangement is also able to detect when the padlock is being unlocked from a verified locked state. This may be implemented by detecting a change of magnetic flux from said first magnetic flux. In the illustrated embodiment, the position detecting device is arranged to detect also the unlock position of the rotatable lock core 23 in response to the magnetic sensor 24 detecting a magnetic flux change from said first magnetic flux. The position detecting device is further arranged to generate unlock data in response to detecting said unlock position in combination with said detected flux change. The padlock 10 is arranged to transmit the unlock data to the inserted electronic key 40 as a verification that the padlock 11 has been unlocked from a verified locked state. The electronic key now “waits” for an acknowledgement that the padlock 10 has been brought back to its verified locked state.

It may be noted that according to the inventive concept, the magnet is not required for unlocking the padlock. The magnet and the position detecting device are arranged to provide an additional level of security that the padlock is handled correctly and being both locked and locked at the correct location.

Operation of 1st embodiment

The operation of the 1 ^st embodiment in Fig. 1 will now be described with reference to Figs 2A-2I, and the flow chart in Fig. 3.

Fig. 2A illustrates an initial state where the electromechanical padlock 10 is in a verified locked state, that is the padlock 10 is both locked and is in correct location (near the lock fitting) with the handheld unit 30 attached. Steps S1 to S3 in the flowchart in Fig. 3 are now to be performed. A user intending to unlock the padlock 10 is carrying a programmable electronic key 40 and a mobile phone 110 with an installed associated app. The user activates the electronic key 40 by pressing the activation button 41. The key 40 thereby receives authorization data from a cloud based or locally hosted access control system 120, 130. The key 40 acknowledges the activation by briefly flashing the LED of the key 40.

In Fig. 2B (Step 4), the activated key 40 is inserted into the lock core 23. The padlock 10 is thereby powered by the key 40. The key 40 communicates with electronics in the lock core 23. An authorization code transmitted from the key 40 to the lock core 23 is verified by the electronics therein. An electromagnet (not shown) is activated in the padlock, allowing the padlock shackle 12 to be opened. When the key 40 is inserted, the lock core 23 is in its lock position, where the magnetic sensor 31 on the lock core 23 is detecting a first magnetic flux from the attached magnet 31 through the housing 11 . As described above, this is a verified locked state of the padlock 10. In the illustrated embodiment, the padlock 10 now transmits the verification data generated by the position detecting device to the key 40 (Step S5 and Step S6). In simpler embodiments, this initial generation and transfer of verification data may be dismissed with. However, it may give an additional security. If for instance the verification data is not received upon key insertion, the key 40 “knows” that there something wrong, for instance that the handheld unit 30 is not attached to the padlock 10 and/or the shackle 12 is not correctly locked in the housing 11 . The user now turns the key 40 as illustrated by the arrow in Fig. 2B to unlock the padlock 10 (Step S7).

In Fig. 2C, the padlock 10 has been unlocked with the key 40 turned 90 degrees, and the lock core 23 has thereby been rotated to its unlock position. The magnetic sensor 24 on the lock core 23 has thereby been rotated away from the magnet 31 . The position detecting device of the padlock 10 now detects a change in magnetic flux detected by the magnetic sensor 24. This is a change from the first magnetic flux to a different magnetic flux, or to no detected flux at all. A threshold arrangement may be used for forming a digital signal, where 1 represents the first magnetic flux and the locked core position, and 0 represents a lower detected magnetic flux (or no flux at all) and the unlocked core position. Since the padlock 10 has been unlocked from a verified locked state (locked + first flux detected), the position detection device generates unlock data (Step S8). The unlock data is transferred to the electronic key 40 and stored therein (Step S9). The user now removes the opened padlock 10 from the staple 52 (Step S10), and detach the handheld unit 30 from the padlock 10 (Step S11 ).

In Fig. 2D, the user is opening the unlocked hasp 51 in order to open the door 60. The user is putting the padlock 10 aside by temporarily hanging it in the staple 52, now without the handheld unit 30 attached. In the illustrated embodiment, the key 40 can be withdrawn from the padlock 10 only if the padlock is locked. In order not to leave the key 40 unguarded, in Fig. 2E the user temporarily locks the padlock to the staple 52 in order to withdraw the key 40. It should be noted that the padlock 40 in Fig. 2E is not in its verified locked state since the magnet 31 was not in position when the padlock 10 was locked. Accordingly, no verification data was generated and sent to the key 40. The key 40, having stored there in the unlock data previously received from the position detecting device, is therefore still waiting for the required locking acknowledgment in the form of verification data from the padlock 10.

In Fig. 2F, the user is initiating the procedure for closing and relocking the door 60. The hasp 51 with the handheld unit 30 attached thereto is swung back over the hasp 52. The handheld unit 30 is hanging freely in the relatively short connector member 33. In Fig. 2G, the padlock 10 has been unlocked. Fig. 2G shows a first sequence where the user first inserts the key 40 and unlocks the padlock 10 by rotating the key, and thereafter attaches the handheld unit 30 to the unlocked padlock. (Step S13). In this alternative, no new unlock data is generated since the padlock 10 was not unlocked from a verified locked state (unit 30 not attached during unlocking). As an alternative, the user reattaches the handheld unit 30 before inserting the key 40. In this alternative, new verification data will be generated and transmitted to the key 40 when the key 40 is inserted, said verification data being stored in the key 40.

In Fig. 2H, the user turns the key 40 to relock the padlock 10 (Step S14). The lock core 23 is thereby rotated to its lock position in which the magnetic sensor 24 again detects said first magnetic flux from the attached magnet 31 . In response thereto, the position detection device generates verification data (Step S15), which is transmitted to the key 40 (Step S16). The key 40 has now received the awaited verification data as an acknowledgement or receipt that the previously opened padlocklO has been locked into a verified locked state. As a preferred option, the key acknowledges e.g. by a brief LED flashing that the verified locked state has been obtained (Step S17), that is the padlock 10 has been locked and it has been locked in the correct location with the handheld unit 30 attached. This is done before the key 40 is withdrawn. In preferred embodiments, the key is able to provide such acknowledgement if it is in its inserted position.

In Fig. 2I, having received the acknowledgement from the key 40 that the padlock 10 has been correctly relocked at the correct location, the user withdraws the key 40 and leaves the location.

Reference is now made to Fig. 4, illustrating a system where the inventive arrangement and method are implemented. The user is carrying the electronic key 40 and a mobile phone 110 provided with an associated app. In the illustrated embodiment, the key 40 and the mobile phone 110 may communicate wirelessly, e.g. via Bluetooth, and the mobile phone 110 may in its turn communicate via the cloud service 120. The key 40 may also, or as an alternative to the communication with the phone 110, wirelessly communicate with a cloud service 120 via a wireless gateway 140 arranged at the site where the lock fitting 50 is located. As a further alternative or addition, the key 40 may communicate with a synchronization unit 130. The synchronization unit 130 may be located at an office or in a car as an example. As a non-limiting illustrative example, a user may insert the key 130 into the synchronization unit 130 at the beginning of the day to load access codes into the key 40. At the end of the day, the user reinserts the key 30 into the synchronization unit 130 for removing the access codes and for transferring log data. Using one or more of these communication paths, the electronic keys 40 may receive updated authorization data on a daily basis.

The overall system may use geofence technology designed such that when a user moves away more than a predetermined distance from the location of the lock fitting 50 and the padlock 10, such as more than 50 meters, the mobile phone 110 establishes contact with the electronic key 40 to receive an acknowledgement that the padlock 10 is in the verified locked state. In this manner, a complete log file may be collected in the mobile phone 110 and transmitted further to the cloud service 110 and/or the synchronization unit 130. Incorrect locking procedures where acknowledgement were not received may also be stored in the key 40 and subsequently transferred as error log data to the mobile phone 110 or directly to the cloud service 120 or the synchronization unit 130.

If the app has correctly received a verified locked state acknowledgement, the app provides a message to the user as a receipt that it has received a correct acknowledgement. On the other hand, if the app does not receive any verified locked state acknowledgement from the key 40, the app may generate a warning signal (light/sound) and a message on the mobile phone to the user with a text like “Check that you have locked the padlock at the correct location!” This procedure may be repeated either until the user acknowledges the warning, or until the app correctly receives a verified locked state acknowledgement from the key 40.

As an alternative, the programmable key 40 may be programmed to start blinking in a predetermined sequence in a situation where the user has first unlocked a padlock from a verified locked state (magnet unit attached) but subsequently failed within a predetermined period, e.g. 30 minutes, to lock the padlock correctly again with the magnet unit 30 attached.

2 ^nd embodiment

Reference is now made to Figs. 5A-5C illustrating a second embodiment of the handheld unit 30. Like parts have the same reference numerals. What has been described above for the handheld unit 30 in the first embodiment also applies to this second embodiment, especially the functional part thereof. The handheld unit 30 according to the second embodiment is designed such that it may be locked to the padlock 10 by using the shackle 12 of the padlock. To this end, the handheld unit 30 further comprises a top part 34 covering part of the top surface 15 of the housing 11 between the legs 13 and 14 of the shackle 12. The handheld unit 30 comprises an opening 35, in this embodiment formed in or next to the top part 34 at the location of the free end 14 of the shackle 12. When the handheld unit 30 is in its position of use, the opening 35 will receive the free shackle end 14 when the padlock 10 is locked, thereby locking the handheld unit 30 to the padlock 10.

As shown in Figs 5A-5C, the design may also be such that the height of the handheld unit 30 corresponds to the height of the padlock housing 11. A bottom part 36 of the handheld unit 30 may be added to ensure a correct vertical position. Furthermore, by designing the shape of the handheld unit 30 to follow the shape of the housing 11 , and by also covering the top surface 18 and the bottom surface 19 at least partly, the positioning recess 22 may be dispensed with. This has the advantage that the shape of the padlock housing 11 does not have to be designed in any special way. In the illustrated embodiment, the magnet 31 may be flush with the attachment member since it does not have to act as a projecting guide pin as in the first embodiment.

Alternatives The design of the handheld unit may be “flexible” in the sense that one handheld unit design may be used for various padlocks having different shapes, or padlocks having different shackle dimensions. For instance, the U shaped attachment part may be flexible to adapt to varying padlock thickness. And the opening or openings for the shackle may be oversized to be able to receive different sized shackles.