The invention relates to an alarm system having a central unit and a smart lock. The invention further relates to an alarm installation.

Alarm installations or alarm systems for buildings are generally known. Typically, they comprise a control unit and a couple of intrusion detection devices, in particular magnet sensors which send a signal when a door or a window is being opened. After receipt of such signal, the user has a predefined time period within which he has to disarm or deactivate the alarm system, for example by entering a pin or code at a central unit (also referred to as“control unit”). If the alarm system is not deactivated within the predefined time period, the control unit assumes that there is an alarm situation.

The term“building” here refers to small businesses and homes. These can be houses or flats within a house.

It is also known to use a so-called smart lock for operating a door lock. Such smart lock is a device for electrically actuating a deadbolt of the door.

Generally speaking, such smart lock takes over the function of a mechanical key. It allows operation of the door lock only for authorized people, for example those who carry a transponder or a smartphone with an app connected to the smart lock, and it moves a deadbolt of the door lock from the closed position to an open position so that the door can be opened, or from the open to the closed position so that the door is locked.

A typical smart lock comprises an electric motor which provides the mechanical power for operating the deadbolt, batteries for providing the electrical power for operating the motor, and a control also supplied from the battery for controlling operation of the motor. The control receives an authorization signal indicating that an authorized person is in the vicinity of the door equipped with the smart lock.

The object of the invention is to improve the usability of the smart lock and to increase the security level provided by the alarm installation. To this end, the invention provides a method of operating an alarm system having a central unit and a smart lock, the smart lock having an accelerometer and an RF module, the central unit having an evaluation module for evaluating acceleration signals provided via the RF module from the smart lock, the evaluation module being adapted for distinguishing between at least two of the following situations:

- a rotation of the smart lock about a horizontal axis,

- a tilting of the smart lock about an axis which is perpendicular to the horizontal axis,

- rotation of the door to which the smart lock is mounted,

- vibrations resulting from an interaction with the smart lock,

- shocks resulting from an interaction with the door,

- stop of the door in an open position,

- closing of the door,

- a predefined sequence of knocks on the door or on the smart lock.

Further, the invention provides a alarm installation having a central unit and a smart lock, the smart lock being adapted to be mounted on a door, the smart lock comprising a battery, an accelerometer and an RF module each located inside a housing, the accelerometer and the RF module arranged to provide a RF signal indicating accelerations acting on the smart lock.

The invention is based on the integration of the accelerometer into the smart lock so that additional signal are available which can be evaluated and allow either to detect that there is an attempt to tamper with the door and/or the door lock, or to provide additional comfort to the user.

The accelerometer signals allow detecting that the smart lock is being tilted about an axis which coincides with its central axis. This is an indication that there is an attempt to remove the smart lock from the door which will trigger an alarm unless the central unit has in advance received a maintenance signal which indicates that the smart lock will be removed from the door, e.g. for replacement of a battery.

The accelerometer signals allow detecting that the smart lock is being tilted about a horizontal axis which is perpendicular to the central axis of the smart lock. This is an indication that the smart lock has been removed from the door as such tilting cannot occur if the door lock is properly mounted to the door, and will trigger an alarm unless the central unit has in advance received a maintenance signal which indicates that the smart lock will be removed from the door, e.g. for replacement of a battery.

The accelerometer signals can be used to detect vibrations on the door and/or the smart lock which are the result of the use of a drill, and detect shocks which are the result of an attempt to pry open the door or break it. In both of these situations, an alarm is triggered.

The alarm can involve activation of a camera and/or a microphone. This information obtained thereby can be sent to a user so it is available e.g. on a smart phone. In addition or as an alternative, the information can be sent to an operations center so that personnel can decide if the police or a guard should be notified.

The alarm can also involve activation of at least one of a siren, a loudspeaker and an alarm light so that an intruder is scared off.

The accelerometer signals can be used to detect that the door is not in a closed position, either because it is still moving or has come to a stop in an open position. This can initiate generation of a delay signal which prevents the smart lock from moving the deadbolt from an unlocked position into a locked position.

The accelerometer signals can also be used to allow a user an automated locking of the door lock. This this end, the user stores in the central unit a predefined sequence of knocks on the door or the smart lock. If the accelerometer signals correspond to this sequence, a locking signal is sent to the smart lock for moving the deadbolt of the door from an unlocked to a locked position.

The invention will now be described with reference to the enclosed drawings. In the drawings, Figure 1 schematically shows in a cross section a door with a door lock actuation device,

Figure 2 shows a cross section through a door lock actuation device according to the invention,

Figure 3 shows a cross section of the door lock actuation device of Figure 2 in a view similar to that of Figure 1 ,

Figure 4 shows details of the locking mechanism for locking the battery cover to the housing,

Figure 5 shows the screw used in the locking mechanism,

Figure 6 shows the battery cover in a perspective view, and

Figure 7 shows an alarm installation employing the door lock actuation device as shown in Figures 1 to 6.

Figure 1 schematically shows a door 1 which is provided with a deadbolt 2. The deadbolt 2 can be moved between a closed or locked position (in which it protrudes outwardly over the respective end face of the door) and an open or unlocked position (in which it is retracted into the door so as to not protrude over the end face) by means of a door lock actuation device 10 (referred to in the following as “smart lock”).

Smart lock 10 comprises a housing 12 which is mechanically mounted on a carrier 3. Carrier 3 is screwed or otherwise mechanically connected to door 1 .

The side of the housing which is mounted to carrier 3 is referred to as being an interface side of the housing.

Within housing 12, a drive device 14 (here in the form of an electric motor) is arranged which is operatively connected to an output element 16. Output element 16 is operatively connected to deadbolt 2 so that rotation of output element 16 moves the deadbolt from the locked position to the opened position, and vice versa.

Within housing 12, a battery compartment 18 is formed in which a battery 20 is arranged. Battery 20 provides the electric energy for operating drive device 14. Within housing 12, there is also arranged a control 22 for controlling operation of drive device 14. The energy necessary for operation of control 22 is also provided by battery 20.

On the side remote from door 1 , smart lock 10 is provided with an operating element 24 (e.g. a thumb turn) which is mechanically connected to output element 16 and allows rotation of the output element in case of need (e.g. a failure of the drive device or a lack of electric energy from batteries 20).

Figures 2 to 6 show details of the construction of smart lock 10 according to the invention.

One element of the smart lock according to the invention is a tamper-proof battery cover 26 which forms the external wall of battery compartment 18.

Battery cover 26 has the shape of an approximately semi-circular shell and is provided with two locking tabs 28 at opposite ends. As can be seen in Figure 6, each locking tab 28 extends over the entire width of battery cover 26.

As can be seen in particular in Figure 2, locking tabs 28 engage, when battery cover 26 is mounted to housing 12, behind edges of housing 12. Locking tabs 28 are comparatively long in the circumferential direction so that there is a significant overlap between locking tabs 28 and housing 12.

Locking tabs 28 extend so far in under housing 12 so that there will never be a gap between battery cover 26 and housing 12 when somebody tries to pry the battery cover open, even if battery cover 26 flexes a little bit when put under load during an attempt to pry it open.

As locking tabs 28 extend over the full width of battery cover 28, this avoids any gap in the corners while battery cover 26 is flexing.

It can also be seen that the free ends of locking tabs 28 are arranged at a small distance from an interior wall 30 which can form an abutment for locking tabs 28 in case somebody tries to press the entire battery cover into the housing.

Battery cover 26 is provided with a support block 32 on its inner surface approximately in the middle between locking tabs 28. As can be seen in particular in Figures 3 and 4, support block 32 is provided with an opening 34 through which a screw 36 extends.

Screw 36 has a stepped thread at its forward portion, namely a thread 38 with a first diameter portion 38 and a second diameter portion 40. The second diameter is larger than the first diameter.

Examples for the diameters can be 2 mm for the first diameter portion 38 and 3 mm for the second diameter portion 40.

Threads 38, 40 are arranged such that the first diameter portion 38 engages into housing 12 (please see in particular Figure 4) while second diameter portion 40 is threaded into support block 32. To this end, opening 34 in support block 32 of battery cover 26 is provided with a reduced diameter at the end remote from the head of screw 36.

Screw 36 thus mechanically engages both housing 12 and battery cover 26.

As an alternative to a stepped screw, a screw with a continuous thread could be used.

Support block 32 together with screw 36 forms a locking mechanism which is accessible only from the interface side of housing 12 (the side of the housing adapted for being mounted on carrier 3). This can be seen in particular in Figure 3. This effectively prevents any opening of battery compartment 18 as long as smart lock 10 is properly mounted to door 1 .

This protects the smart lock from a tampering attempt in which electrical power to the lock is removed without first removing the smart lock from the door.

Control 22 is mounted on a PCB 42 which is arranged within housing 12. Walls 30 can be used for mounting PCB 42 within housing 12.

PCB 42 also carries an accelerometer 46. Further, a communication module 48 (hereinafter referred to as“RF module”) is arranged on PCB 42.

It is also possible to use more than a single PCB. As an example, a first PCB carrying the control of the smart lock can be provided, and a second PCB with the accelerometer and the communication module 48. With communication module 48, signals received from the accelerometer 46 can be sent to an alarm installation. The alarm installation can comprise other components such as glass breakage sensors, window sensors and door sensors.

An example of such alarm installation is shown in Figure 7.

In Figure 7, reference numeral 50 designates the living space of an apartment or a house. Door 1 provides access to living space 50. The door is equipped with smart lock 10.

A central unit 52 is provided in the apartment or the house, which is part of an alarm installation. Additional intrusion detection devices, in particular magnet sensors which send a signal when a door or a window is being opened, or a glass breakage sensor are part of the alarm installation.

Central unit 52 has a communication module 54 which can receive RF signals from smart lock 10, in particular the signals from the accelerometer. Central unit 52 can also send signals to smart lock 10 so as to control operation of drive device 14.

Central unit 52 further includes an evaluation unit 56 for evaluating the accelerometer signals received from smart lock 10. Depending from the result of the evaluation, a plurality of different situations or occurrences can be detected, and control unit 52 can react with a specific response.

Central unit 52 also includes an external communication device 58 via which a communication with an external monitoring station 60 (operations control).

Generally speaking, evaluation module 56 is used to distinguish between a plurality of different situations.

A first situation consists in somebody removing smart lock 10 from door 1 without prior authorization.

Signals indicative of such attempt comprise a rotation of the smart lock about a horizontal central axis of the smart lock, and a tilting of the smart lock about a horizontal axis which is perpendicular to the central axis.

Typically, smart lock 10 is mounted to door 1 by means of a bayonet connection between smart lock 10 and carrier 3, the bayonet connection requiring a rotation of smart lock 10 around the central axis of the smart lock, this axis being perpendicular to the door. For removing the smart lock from the door, a rotation in the opposite direction is necessary.

Should the signals of the accelerometer indicate that there is a rotation of smart lock 10 around an axis which is horizontal and perpendicular to door 1 , this is an indication that smart lock 10 is rotated so as to remove it from carrier 3 and thus from door 1 . Should there be a rotation around a horizontal axis which is perpendicular to the first horizontal axis, this is an indication that smart lock 10 has been removed from door 1 as in a properly mounted condition, smart lock 10 can be rotated only around a vertical axis which coincides with the hinge axis of door 1 .

If central unit 52 detects that smart lock 10 is rotated or tilted in a manner which should not occur during normal operation, an alarm can be triggered. The alarm can involve a notification sent to monitoring station 60, and/or involve activation of a siren, a loudspeaker and/or an alarm light.

The alarm can also put the entire alarm installation into a state of higher alert. In this state, a microphone and/or a camera 62 can be activated, and the information captured therewith can be transmitted either to operations control 60 for a decision whether or not the police should be notified or a guard should be sent, and/or the user so that he/she can see e.g. on his/her smartphone what is going on.

The information captured by the microphone and/or the camera can also be evaluated by evaluation module 56 in order to detect it there is an intrusion or not. This reduces the number of false alarms.

Should a user intend to replace batteries 20, a maintenance signal is to be sent to central unit 52. The maintenance signal can either be sent from monitoring station 60 or can be initiated by the user directly at central unit 52, for example by inserting a corresponding PIN code. Subsequently, removal of smart lock 10 from door 1 is authorized without an alarm being triggered.

The signals sent from accelerometer can also be used for detecting other attempts of tampering with smart lock 10 and/or door 1 . As an example, shocks resulting from an interaction with the door, for example from somebody trying to pry open the door, can be detected and result in an alarm being triggered. Further, vibrations resulting from an interaction with the smart lock and/or the door can indicate that somebody tries to drill a whole into the door and/or the smart lock. In this case, an alarm is triggered as well.

The signals received from the accelerometer can also be used for improving the operation of smart lock 10.

It is known that a smart lock can move deadbolt 2 of door 1 from an unlocked to a locked position after a predefined period of time after opening of the door. The signals received from the accelerometer can either extend this time period or completely prevent smart lock 10 from locking deadbolt 2, as long as the door is being moved. Locking of deadbolt 2 can also be prevented when the signals of the accelerometer indicate that the door has come to a stop in an open position.

Central unit 52 can also make smart lock 10 move deadbolt 2 towards a locked position when the signals received from the accelerometer indicate that there has been a contact between the door and the door frame, and the door has subsequently remained in a stationery condition. Then, an automatic locking of the door can be initiated.

The signals received from the accelerometer can also be used to“overrule” an automated locking sequence implemented in the smart lock. It is known that the smart lock automatically moves the deadbolt from an unlocked to a locked position at a predetermined point in time after it was unlocked (for example 5 seconds). Central unit 52 can generate a delay signal which extends this time period as long as the signals received from the accelerometer indicate that either the door is still being moved or that the door has come to a stop in an open position. In both of these cases, it does not make much sense to move the deadbolt towards a locked position.

The signals received from the accelerometer can also be used to very conveniently make smart lock 10 lock deadbolt 2. It is possible that a user stores in central unit 52 a specific sequence of knocks on the door or the smart lock itself. Should the central unit receive signals from the accelerometer which correspond to this sequence of knocks after having previously received signals which indicate that the door has been closed, smart lock 10 is commanded to move deadbolt 2 into the locked position. It is thus possible for a user to close the door and knock on the door from the inside or outside with the predefined sequence so as to lock the door without any further steps.