EP0676519A1

EP0676519A1 - A security system including a lock

Info

Publication number: EP0676519A1
Application number: EP94302390A
Authority: EP
Inventors: Peter Alfred Terry; Robert Dettmer
Original assignee: TOTAL SECURITY INSTALLATIONS Ltd
Current assignee: TOTAL SECURITY INSTALLATIONS Ltd
Priority date: 1992-09-17
Filing date: 1994-04-05
Publication date: 1995-10-11
Also published as: GB2271141B; GB2271141A; GB9219681D0

Abstract

A security system for a lock (22) is mounted within the door (2) of a hotel safe. Bolts (4) of the electrically operated lock (22) for the door can only be retracted when a solenoid (72) controlling a locking pin (74) is energised by a microprocessor (40). The hotel guest inputs a personal code into memory (42) before locking the safe. To reopen the safe, the guest has to key in the same code using a keypad (6) on the front of the door (2). If the input code corresponds to the one stored, the solenoid (72) can be energised to allow opening of the lock. If the guest forgets the code, the safe can be opened by connecting a separate override unit thereto so that an override unit processor communicates with said microprocessor (40). The override unit is connected by way of a socket (18) and if the override processor means successfully communicates with the security system processor means (40) it is enabled to read, and subsequently to generate, a preset override code stored in the memory (42) whereby opening of the lock is enabled.

Description

The present invention relates to a security system comprising a lock, for example, for a hotel or other security safe.
It is known to provide safes which are opened by keying in a predetermined code. However, unless the code can be programmed, and therefore changed, difficulties arise where the user forgets the code and/or stores details of the code in a non-secure manner. Furthermore, a safe provided, for example, in a hotel bedroom, requires that a master key or other override facility be provided to enable access to the safe as guests change and/or if the guest is unable to open the safe in the prescribed manner.
US-A-4684945 describes a security system comprising a lock including a locking mechanism arranged to open and close the lock, processor means arranged to control the operation of the locking mechanism, and user input means coupled to, and arranged to input a user selected code to the processor means, wherein said processor means comprises programmable storage means storing a preset code, and wherein said processor means is responsive to said user input means and is arranged to enable operation of said locking mechanism if a user selected code input by said user input means corresponds to said preset code, and further comprising override means arranged to enable operation of said locking mechanism by generating a predetermined override signal for input to said processor means.
The override system of US-A-4684945 requires that the hotel guest or other person operates the safe to generate a part code. The safe uses this part code to generate an override code which is stored therein. The part code is then input into the hotel computer which is provided with the same encryption routine as the safe. The computer generates the override code which can then be input to the safe to open it.
This override process is long and cumbersome, and where a person is required to remember or record the override code, the process is also insecure and puts the person knowing the override code at risk. This can be obviated by taking a portable computer programmed with the encryption routine to the site of the safe to generate the override code, but this is also an inconvenient and cumbersome process.
It is an object of the invention to provide a security system having an override facility which is at least also secure but more convenient than hitherto.
According to the present invention, a security system of the type defined is characterised in that said override means comprises a separate override unit having connecting means for selectively connecting said override unit to said processor means, and having override processor means arranged, when said override unit is coupled to said processor means of the security system, to communicate with said security system processor means, and in that said override processor means is arranged to generate a communication code and to ensure that a predetermined response code is generated by the security system processor means, wherein, upon receipt of said predetermined response code, the override processor means is enabled to read a preset override signal or code stored in said storage means, and is then arranged to generate the override code whereby operation of the locking mechanism of the security system is enabled.
The separate override unit of a security system of the invention may be thought of as an electronic master key. As it generates the override code by reading the stored override code, it can be used to open each of a plurality of different safes.
The override processor means is arranged to generate a communication code and to ensure that a response code is generated by the security system processor means. It is only when this "handshake" communication operation between the two processor means has been correctly and satisfactorily completed, that the override processor means is allowed to read the stored override signal or code.
It is advantageous that the override unit is arranged to generate the appropriate override code. This enables the override code to be chosen, and changed if necessary, by the safe owner. It also means that it is not possible to interrogate the override unit in order to determine the override code. If the override unit itself is stolen the "handshake" protocol, which enables the override and security system processor means to communicate, can be changed.
The security system may be arranged such that the override facility is by way of the separate override unit only, or by either the separate override unit or the user input means.
If required, the override code may be preset by the factory and not programmable.
In normal operation of an embodiment of a security system of the invention, a user can open the lock, for example of a safe, by inputting a code by way of the user input means which corresponds to the preset code. For example, the user input means may be a keyboard or keypad and the user is required to key in the preset code, which the user may have pre-programmed earlier.
The keyboard or keypad may be incorporated in the security system or may be separate therefrom. A separate user input means may be physically connected to the security system or appropriate transmission means may be provided such that the user input means may be operable remotely.
This means that, for example, a hotel safe may be preprogrammed by a hotel guest such that the preset code is a code, generally a four digit code, known only to the guest. Access to the safe is then obtained by the guest when required by keying in the selected and pre-programmed four digit code. Access to the safe is denied to others including hotel staff. However, if the guest forgets the code or cannot otherwise open the safe, a responsible member of the hotel staff can utilise the override facility to enable access to the safe.
Normally, the processor means can offer the ability to program the preset code each time the safe is opened. This means that a departing guest simply leaves the safe unopened and an incoming guest then programs a new code when using the safe for the first time. However, it additionally and/or alternatively may be provided that opening the locking mechanism by way of the override unit is necessary in order to initialise the storage means and enable the input of a further programmable preset code.
For safes provided in hotel rooms it may be that the input of the user selected and pre-programmed code is generally all that is required in order to open the safe. However, for further security it may be required that the safe can only be opened at particular times of the day and/or that there is a preset delay time after a user selected code is input before operation of the locking mechanism is enabled. The provision of a short delay before a safe can be opened is a very simple, yet effective deterrent against thieves.
Accordingly, in a preferred embodiment the security system further comprises a timing unit coupled to, and arranged to provide time information to, said processor means, the storage means of said processor means storing preset time information, and wherein said processor means is responsive to said timing unit and is arranged to prevent operation of said locking mechanism if time information provided by said timing unit does not correspond to the stored preset time information.
For example, the locking mechanism may only be enabled to open if time information from the timing unit corresponds to preset time information and a user inputs the preset code. In this respect, the time information may be a predetermined time delay, for example, of several minutes. Additionally and/or alternatively, the time information may relate to the time of day and may prevent opening of the safe outside preset times.
Preferably, both the preset time information and the preset code may be programmed by the user. For example, programming of the preset time information and the preset code may be by way of the user input means.
Preferably, in order to initiate reprogramming of stored preset information, it is necessary to actuate a programming button, coupled to said processor means, to signal to said processor means that stored information is to be changed. For security reasons it is necessary to restrict access to the programming button. When the security system is provided on a safe, for example, the programming button may be provided inside the safe. Additionally and/or alternatively reprogramming may be initiated by said override unit.
In a preferred embodiment, the security system further comprises battery means coupled to supply electrical power to said security system, and means for disconnecting said battery means from selected parts of the security system.
Preferably, said disconnecting means operate to disconnect said battery means from at least said locking mechanism a predetermined time after the locking mechanism is operated.
In a preferred embodiment, the processor means is arranged cyclically to look at the state of the user input means. If a demand exists for operation of the locking mechanism, the processor means is responsive thereto and is arranged to connect said battery means to the selected parts of the security system.
Preferably, the lock further comprises electrically operable means normally arranged to retain the lock or the locking mechanism in the closed position of the lock. In response to a user demand, the processor means is arranged to energise said electrically operable means which thereby enable opening of the lock. In this embodiment, said disconnecting means are arranged to disconnect said battery means from said electrically operable means.
The user input means may comprise sensing means for sensing a user attempt to open and close the lock and signalling a user demand to said processor means. For example, a knob or lever may be provided for actuating said locking mechanism and a micro switch may be associated with the lock or lever and/or with the locking mechanism.
Additionally, the user input means may comprise user input means arranged to input a user selected code as defined above. In this case, the user input means may comprise, for example, a keypad. Of course, and as specified above, the user input means for inputting a user selected code may also be a remote device if required.
According to a further aspect of the present invention there is provided a security system comprising a lock including a locking mechanism arranged to open and close the lock, processor means arranged to control the operation of the locking mechanism, a timing unit coupled to, and arranged to provide time information to, said processor means, and user input means coupled to, and arranged to input a user selected code to the processor means, wherein said processor means comprises programmable storage means storing preset time information and a preset code, and wherein said processor means is responsive to said timing unit and to said user input means and is arranged to enable operation of said locking mechanism if the time information provided by said timing unit corresponds to said preset time information and if a user selected code input by way of said user input means corresponds to said preset code.
With an embodiment of this further aspect of the present invention the security system is only enabled to operate the locking mechanism, for example, to open a safe, if time information from the timing unit corresponds to preset time information and a user inputs the preset code. In this respect, the time information may be the expiry of a predetermined time delay after a user selected code is input. This introduces a time delay before operation of the locking mechanism is enabled. The delay may be chosen as required, and may, for example be several minutes. Additionally and/or alternatively, the time information may relate to the time of day and may prevent opening of the safe outside preset times.
Preferably, both the preset time information and the preset code may be programmed by the user. For example, programming of the preset time information and the preset code may be by way of the user input means.
Preferably, in order to initiate reprogramming of stored preset information, it is necessary to actuate a programming button, coupled to said processor means, to signal to said processor means that stored information is to be changed. For security reasons it is necessary to restrict access to the programming button. When the security system is provided on a safe, for example, the programming button may be provided inside the safe.
In an embodiment, a security system of the invention further comprises override input means to which said processor means is responsive and which is arranged to be coupled to said processor means and to enable operation of said locking mechanism if a predetermined override signal is input to said processor means by said override input means.
In a preferred embodiment said predetermined override signal is a preset override code stored in said storage means. Preferably, this preset override code is programmable.
In an embodiment, the override input means substantially comprises said user input means. The override preset code may be a ten digit code which is to be input by way of a keyboard or keypad.
Additionally and/or alternatively, the override input means comprises a separate override unit having connecting means for selectively connecting said unit to said processor means. Thus, the override unit may be considered to be an electronic master key.
Said override unit preferably comprises override processor means arranged, when the unit is connected to the processor means of the security system, to communicate with the processor means of the security system. The override unit may be enabled to generate the necessary override code and to thereby enable operation of the locking mechanism of the security system.
In a preferred embodiment, the security system further comprises battery means coupled to supply electrical power to said security system, and means for disconnecting said battery means from selected parts of the security system.
Preferably, said disconnecting means operate to disconnect said battery means from at least said locking mechanism a predetermined time after the locking mechanism is operated.
In a preferred embodiment, the processor means is arranged cyclically to look at the state of the user input means. If a demand exists for operation of the locking mechanism, the processor means is responsive thereto and is arranged to connect said battery means to the selected parts of the security system.
Preferably, the lock further comprises electrically operable means normally arranged to retain the lock or the locking mechanism in the closed position of the lock. In response to a user demand, the processor means is arranged to energise said electrically operable means which thereby enable opening of the lock. In this embodiment, said disconnecting means are arranged to disconnect said battery means from said electrically operable means.
The user input means may comprise sensing means for sensing a user attempt to open and close the lock and signalling a user demand to said processor means. For example, a knob or lever may be provided for actuating said locking mechanism and a micro switch may be associated with the lock or lever and/or with the locking mechanism.
Additionally, the user input means may comprise user input means arranged to input a user selected code as defined above. In this case, the user input means may comprise, for example, a keypad. Of course, and as specified above, the user input means for inputting a user selected code may also be a remote device if required.
The present invention also extends to a security system comprising a lock including a locking mechanism arranged to open and close the lock, input means for demanding operation of the locking mechanism, processor means responsive to said input means and arranged, in response to a demand from said input means, to enable operation of the locking mechanism, and battery means coupled to supply electrical power to said security system, and further comprising means for switching off selected parts of said security system when operation of said locking mechanism is not demanded.
By providing means for switching off parts of said security system when operation of said locking mechanism is not demanded, an embodiment of this aspect of the invention ensures that the life of the battery means is as long as is possible.
Preferably, said means for switching off parts of the security system comprise means for disconnecting said battery means from said selected parts. In an embodiment, said selected parts comprise at least said locking mechanism.
Preferably, said disconnecting means operate to disconnect said battery means from at least said locking mechanism a predetermined time after the locking mechanism is operated. For example, disconnection may occur one minute after operation.
The batteries will remain connected to supply power to the processor means, but the disconnecting means may be arranged to shut down not only the locking mechanism but other parts of the system.
In a preferred embodiment, the processor means is arranged cyclically to look at the state of the user input means. If a demand exists for operation of the locking mechanism, the processor means is responsive to that demand and is arranged to connect said battery means to said selected parts of the security system.
Preferably, the lock comprises electrically operable means normally arranged to retain the lock or the locking mechanism in the closed position of the lock. In response to a user demand, the processor means is arranged to energise said electrically operable means which thereby enables opening of the lock. In this embodiment, said disconnecting means are arranged to disconnect said battery means from said electrically operable means.
Said input means may comprise sensing means for sensing a user attempt to open and close the lock and signalling a user demand to said processor means. For example, a knob or lever may be provided for actuating said locking mechanism and a micro switch may be associated with the lock or lever and/or with the locking mechanism.
Additionally, and/or alternatively, the user input means may comprise user input means as defined above arranged to input a user selected code to the processor means. In this case, the user input means may comprise, for example, a keypad. Of course, and as specified above, the user input means for inputting a user selected code may also be a remote device if required.
Additionally and/or alternatively, the input means may comprise a pre-programmed routine, for example a preprogrammed time response controlling said processor means. For example, the processor means may be responsive to a timing unit arranged to provide the time of day and the processor means may, in response to a particular time of the day, enable operation of the locking mechanism.
The timing unit may be arranged and constructed as defined above.
Additionally and/or alternatively the input means may comprise one or more of the input means defined above either alone or in combination with other input means. In this circumstance, the processor means is preferably arranged to enable operation of the locking mechanism only when two or more specific demands are received.
The security system comprising the battery disconnecting means as defined, may also comprise the override means defined above.
The security systems defined above comprise a lock arranged to be opened and closed by way of a locking mechanism. For example, the lock may comprise one or more locking bolts, and the locking mechanism may comprise means to reciprocate the bolts to open and close the lock.
In a preferred embodiment, the locking mechanism comprises a rotatable knob or a lever coupled to the bolt or bolts. Preferably, the bolt or bolts are biassed by biassing means to a closed position in which the bolt or bolts are extended and are retractable to an open position by way of the knob or lever against the action of the biassing means. Alternatively, the knob or lever may be movable to selectively retract or extend the bolt or bolts.
In a preferred embodiment, the retraction of the bolt or bolts to open the lock is normally prevented by way of electrically operated means. For example, the electrically operated means may comprise a solenoid arranged, upon energisation, to extend a locking pin such that retraction of the bolt or bolts is thereby prevented. For example, the locking pin may extend in the retraction path of the bolt or bolts or in the path of other elements which need to move to effect retraction of the bolt or bolts.
In a preferred embodiment, a micro switch is associated with the knob or lever and is closed upon attempted operation thereof in a manner to seek to retract the bolt or bolts.
In a preferred embodiment of all of the security systems defined above, storage means is provided and is arranged to store information relating to the operation of the security system. Connector means are provided and enable a separate external interface device to be coupled to the security system and to receive the stored operational information. For example, the separate device may be a host computer and/or a printer. The storage means may comprise the programmable storage means first mentioned above or may comprise second storage means.
Preferably, the input means of the or each security system defined above comprises a tactile membrane keypad. The keypad preferably incorporates indicating means arranged to indicate when the lock has been successfully activated and/or successfully opened.
The security system defined above is preferably incorporated in a safe or other secure cabinet.
The present invention also extends to a safe incorporating a security system as defined above to retain locked the door of the safe.
Embodiments of the present invention will hereinafter be described, by way of example, with reference to the accompanying drawings, in which:

Figure 1 shows a front view of a door for a safe incorporating a security system of the present invention,
Figure 2 shows a rear view of the door of Figure 1 illustrating in elevation components of the security system,
Figure 3 shows on a larger scale the main printed circuit board of the security system shown in Figure 2, and
Figure 4 illustrates a solenoid controlled lock of the security system of Figures 1 to 3.

The drawings illustrate the door of a safe, particularly for use as a hotel safe in the room of a hotel guest. This safe door incorporates a security system including a lock arranged to retain the door of the safe locked unless access is required by an authorised person, such as the hotel guest.
The security system is described hereinafter specifically with reference to a hotel safe. However, it will be appreciated that the security system can be used in any situation where it is required to control the opening and closing of a lock.
Figure 1 shows a front view of the door 2 of a hotel safe (not shown). This door 2 carries a security system for enabling two locking bolts 4 to be selectively extended or retracted to enable opening and closing of the door 2 and locking of the door 2 in its closed position. On its front surface, the door 2 is provided with a tactile keypad indicated at 6. This keypad provides twelve individual keys 8 and also incorporates two indicators 10 each of which is provided with a respective light emitting diode (LED) 12. On the front door 2 of the safe a knob 14 is also provided. This knob 14 is rotatable to retract the bolts 4 when such retraction is available. In the embodiment illustrated, the door 2 of the safe is also provided with a notice 16. Although this notice appears fixed, the notice 16 is removable to provide access to a connector socket 18 shown in Figures 2 and 3.
Figure 2 shows components of a security system of the invention mounted within the door 2 of the safe and also illustrates the rear of the door 2. In this respect, the bolts 4 and the control knob 14 are connected to, and form part of, an electrically operated lock 22. The lock 22 is controlled by way of a main control printed circuit board which is mounted within the door 2 and is indicated at reference 24 in Figure 2, and is shown in Figure 3. Both the electrically operated lock 22 and the main printed circuit board 24 are powered by way of batteries 26 which are appropriately mounted in holders on the rear of the door 2. The security system mounted in the door 2 also comprises a time clock module 28 and a printer printed circuit board 30.
The control printed circuit board 24 is, as made clear above, shown in more detail in Figure 3. On the printed circuit board 24 there is mounted a microprocessor 40 which is in communication with a memory 42. In this respect, the microprocessor 40 is preferably provided with internal memory in which control software is stored. The memory device 42 is preferably programmable, and for example is electrically erasable programmable read only memory (E PROM or EE PROM). The board 24 also carries a crystal oscillator circuit 44 for clocking the microprocessor 40. Appropriate buffer devices (not shown) are provided for connecting microprocessor signals, for example, to the electrically operated lock 22 and, in known manner, the buffer devices may be arranged to amplify control signals from the microprocessor. The connector socket 18 is provided on the board 24, as is an audible indicator device, or sounder 46. The board 24 also carries a connector block 48 for electrically connecting the board 24 and the elements carried thereby to the batteries 26, to the electrically operated lock 22, to the time clock module 28, and to the printer circuit board 30. Any other required connections would also generally be made by way of the connector block 48. Furthermore, the circuit board 24 also carries a keypad connector 50 whereby the board 24 is appropriately electrically connected to the keypad 6.
Figure 4 shows the mechanical construction of the electrically operated lock 22. As can be seen, the two lock bolts 4 are supported on a slide body 60 which is arranged to be reciprocated in the direction of arrow A to extend and retract the bolts 4 relative to a housing 62. The body 60 carries a slide pin 64 engaged within a bore 66 of a slide pin block 68. In the illustrated position shown in Figure 4, the lock bolts 4 are extended. However, it will be appreciated that sliding movement of the slide pin 64 along the bore 66 will enable retraction of the slide body 60 and hence of the lock bolts 4. Furthermore, the slide pin 64 and the bore 66 act to control the sliding movement by ensuring that retraction and extension movements are generally parallel to the direction of the arrow A.
Retraction of the body 60, and hence of the bolts 4, is caused by way of a cam 70 which is rotatably mounted in the housing 62 and can be rotated by the knob 14. In the extended position shown in Figure 4, the cam 70 generally has its largest dimension extending substantially perpendicularly to the direction of extension of the bolts 4. However, it will be appreciated that rotation of the cam 70 rotates the orientation of its largest dimension and retracts the body 60.
As shown in Figure 4, retraction of the bolts 4 is not possible because of a locking pin 74 which extends into the bore 66 and prevents retraction of the slide pin 64. However, this locking pin 74 is carried on a solenoid 72 and energisation of the solenoid 72 is arranged to withdraw the locking pin 74 and hence enable retraction of the body 60 and hence of the bolts 4 upon rotation of the cam 76.
The slide body 60 is provided with a cut out 76 in which a micro switch 78 protrudes. Initial attempts to rotate the cam 70 to retract the bolts 4 cause the cut out 76 to contact and make the micro switch 78 whereby an electrical pulse is generated. The micro switch 78 is connected to the circuit board 24 and the generation of an electrical pulse by the micro switch 78 is monitored by the microprocessor 40.
In operation, with the safe unlocked and open, the microprocessor 40 is programmed such that a preset code and a predetermined delay are stored in the memory 42. The programming is achieved by actuating a program button 20 and then actuating appropriate ones of the keypad keys 8. This program button 20 is provided on the rear of the door 2 and appropriately communicates with the microprocessor 40. The preset code entered is a four digit code and is selected by the user, for example, the hotel guest. The predetermined delay may be factory set or programmed by the user. The safe can then be locked by closing the door and then rotating the control knob 14 to extend the bolts 4.
When it is required to open the safe, the user presses one of the keys 8 which is labelled "Start". Thereafter the user inputs the earlier selected and preset four digit code. On receiving the start signal, the microprocessor 40 looks to see if the code input by way of the keypad 6 is correct. If the information is correct, the microprocessor 40 then waits for the delay period preset as determined by the time clock module 28. At the end of the delay period, one of the LEDs 12 is illuminated to indicate that the safe has been successfully activated. If the user then begins to rotate the control knob 14 to retract the bolts 4, the electrical signal generated by the micro switch 78 causes the microprocessor to energise the solenoid 72. This retracts the locking pin 74 so that continuing rotation of the knob 14 retracts the bolts 4 to open the safe. As the bolts 4 retract a further LED 12 is lit to indicate that the safe has been opened, and to thereby encourage the user to open the safe door.
Whilst the microprocessor 40 does not enable the energisation of the solenoid 72 until it has received the pulse generated by the micro switch 78, the user will not normally detect any delay because of the speed of the microprocessor and solenoid response. To the user it will appear that rotation of the knob 14, upon illumination of the "activate" LED, has caused substantially immediate retraction of the bolts 4.
The time at which the opening occurs and further information about the activity are fed by the microprocessor 40 to a memory (not shown) provided on the printer board 30. This memory on the board 30 is subsequently able to provide a full record of all the operations of the safe.
Some time after the solenoid 72 is energised to enable retraction of the bolts 4, the supply of current thereto is switched off by the microprocessor 40. As the lock bolts 4 have been retracted, the slide pin 64 retains the locking pin 74 in its retracted position out of the slide bore 66. However, if the bolts 4 are subsequently extended, by rotation of the control knob 14, the locking pin 74 will once again extend into the bore 66 and engage behind the slide pin 64 to prevent retraction of the bolts 4.
In the manner of operation as described above, the microprocessor 40 has been arranged to wait a preset time, determined by the time clock module 28, before enabling actuation of the solenoid 72. Additionally and/or alternatively, the security system can be arranged such that it is only possible to actuate the solenoid 72 at certain times of the day. In this respect, the times when operation is to be enabled may be stored in the memory 42 and the microprocessor 40 can then look at the actual time as indicated by the time clock module 28 and compare it with the stored preset times. In this case, the microprocessor will only provide the activate signal to the LED 12 and will only energise the solenoid 72 upon rotation of the control knob 14 when a user seeks access to the safe during the preset time periods. Other constraints on the opening of the safe may be provided. In this respect, the control routines and software of the microprocessor 40 are within the competence of those skilled in the art and are not further described herein.
The printer printed circuit board 30 preferably supports not only a memory but also a further processor (not shown). In this case, the board 30 is then enabled to analyse information received about the number of opening activities attempted, the number of openings effected, and time information and to store this information. Access to the stored information of the board 30 is most easily obtained by transferring the information to an external device such as a computer or to a external printer (not shown) by use of the connector socket 18. In this respect, the notice 16 is peeled back to reveal the socket 18 and an appropriate plug is connected thereto. The printer or host computer communicates with a processor of the security system, and if the communication is appropriate and successful, the information in the memory on the board 30 is transferred to the external device so that it may be displayed and/or printed thereby.
It would be possible for the socket 18 to connect directly with the processor on the printer printed circuit board 30. However, it is preferred that the socket 18 be in communication with the microprocessor 40 of the security system.
The socket 18 is preferably also used to enable the safe to be opened by way of an override facility. The provision of an override facility is important in the case of a hotel safe where it is required to allow guests to operate the safe with a code selected by them. In this respect, it may be necessary, when a guest has left to open the safe so that other guests can enter an alternative code, and a facility to open the safe if a guest forgets the code selected and programmed is equally important. In this respect, the security system can be arranged such that an override code entered by way of the keypad 6 can enable opening of the safe. Additionally, an electronic master key is provided which can be connected to the main control board 24 by way of the socket 18. The socket 18 is a bidirectional port so that two way communication is possible thereby.
The master key is a separate override unit having a plug compatible with the socket 18. The override unit comprises an override microprocessor which is arranged to communicate with the microprocessor 40. Thus, on plugging the override unit to the security system by way of the socket 18, its microprocessor attempts to communicate with the microprocessor 40. In this respect, a communication protocol will require the override unit to provide a recognisable code or signal to the microprocessor 40 and vice versa in order for communication to be established. If an appropriate and satisfactory communication is established, the unit microprocessor then reads a prestored override code from the memory 42. The override unit will then generate the override code and input it to the microprocessor 40, which then enables opening of the safe.
It is possible to provide for overriding of the safe only by use of the override unit. This means that it is not necessary for any one to remember or know the override code. However, if the override unit is stolen, it then becomes necessary to alter the communication protocol used by the override unit processor and the microprocessor to prevent future use of the stolen override unit.
The override code is preferably user programmed. In this respect, it may be arranged that the internal program button 20 is pressed on initialisation and a ten digit override code is entered and stored on initial operation of the safe. Generally, it is preferred that the microprocessor 40 does not enable change of the override code in normal circumstances, for example, upon subsequent pressing of the program button 20.
The override unit is preferably provided with its own keypad. Additional security may be provided by enabling operation of the override unit to establish communication with the microprocessor 40 only if an appropriate security code has been entered by way of the keypad into the override unit.
Where the override unit is provided with input means, as a keypad, it is preferred that change of the override code stored in memory 42 is only allowed by way of the override unit.
The batteries 26 are mounted in holders on the rear surface of the safe door 2 and it is generally required to keep them as modest in size as possible. For example, four 1.5 volt batteries may be provided. Of course, it is also required that the batteries should last for as long as possible and in this respect the microprocessor 40 is arranged to run a routine to shut down most of the security system when not in use to extend battery life. In this respect, the main current is drawn by the solenoid 72 of the lock circuit 22. However, it can be arranged that the solenoid 72 is only energized for, for example, 10 to 20 seconds, for each opening of the lock. Furthermore, a predetermined time after a lock opening, say one minute, the electrical connections to parts of the security system are disconnected by way of the microprocessor. The delay is to enable the collection by the memory of the printer board 30 of the required information. In this respect, power will be needed for the microprocessor, to refresh memories, and by the time module. It may therefore be disconnected from other elements of the system. The microprocessor 40 is arranged to cycle periodically and to reconnect power to the system if it detects that the "Start" key has been activated. If the start key is not activated, the system remains shut down. In this way it is expected that the batteries can be arranged to last for the order of a year or two.
The microprocessor 40 preferably continuously runs routines to check the status of elements of the security system. Specifically, the microprocessor will scan the keypad cyclically to detect any actuation of the keys, and particularly to look for the actuation of the "Start" key. The microprocessor also checks the status of the batteries periodically and of the communication between the various elements of the system. In the event that a drop in voltage from the batteries is detected, or any other abnormal situation, the microprocessor 40 generates an alarm signal by way of the sounder 46.
The invention has been described and illustrated with reference to the particular embodiment of a hotel safe. However, it will be appreciated that the security system may be utilised in other environments.
The particular embodiment described and illustrated shows a keypad incorporated in the security system and the physical connection of an override unit thereto. Of course, physically connected units can be replaced by remotely operable units if preferred.
Furthermore, it will be appreciated that modifications and variations to the security system as described and illustrated, and to a safe incorporating the system, may be made within the scope of this application.

Claims

A security system comprising a lock (22) including a locking mechanism (60, 70-78) arranged to open and close the lock, processor means (40) arranged to control the operation of the locking mechanism, and user input means (8) coupled to, and arranged to input a user selected code to the processor means, wherein said processor means (40) comprises programmable storage means (42) storing a preset code, and wherein said processor means is responsive to said user input means (8) and is arranged to enable operation of said locking mechanism (60, 70-78) if a user selected code input by said user input means corresponds to said preset code, and further comprising override means arranged to enable operation of said locking mechanism by generating a predetermined override signal for input to said processor means, characterised in that said override means comprises a separate override unit having connecting means (18) for selectively connecting said override unit to said processor means (40), and having override processor means arranged, when said override unit is coupled to said processor means (40) of the security system, to communicate with said security system processor means, and in that said override processor means is arranged to generate a communication code and to ensure that a predetermined response code is generated by the security system processor means (40), wherein, upon receipt of said predetermined response code, the override processor means is enabled to read a preset override signal or code stored in said storage means (42), and is then arranged to generate the override code whereby operation of the locking mechanism (60, 70-78) of the security system is enabled.
A security system as claimed in Claim 1, wherein the processor means (40) is arranged to enable the preset code to be programmed each time the locking mechanism (60, 70-78) is operated to open the lock.
A security system as claimed in Claim 1 or Claim 2, further comprising a timing unit (28) coupled to, and arranged to provide time information to, said processor means (40), the storage means (42) of said processor means (40) storing preset time information, and wherein said processor means is responsive to said timing unit (28) and is arranged to prevent operation of said locking mechanism (60, 70-78) if time information provided by said timing unit does not correspond to the stored preset time information.
A security system as claimed in any preceding claim, further comprising battery means (26) coupled to supply electrical power to said security system, and means (40) for disconnecting said battery means from selected parts of the security system, said disconnecting means (40) being operable to disconnect said battery means (26) from at least said locking mechanism (60, 70-78) a predetermined time after the locking mechanism is operated.
A security system as claimed in any preceding claim, wherein said lock further comprises electrically operable means (72) normally arranged to retain the lock or the locking mechanism (60) in the closed position of the lock, and wherein, in response to a user demand at the user input means (8), the processor means (40) is arranged to energise said electrically operable means (72) to thereby enable opening of the lock.
A security system as claimed in any preceding claim, wherein said programmable storage means (42) of said processor means (40) is arranged to store preset time information and said preset code, and comprising a timing unit (28) coupled to, and arranged to provide time information to, said processor means (40), said processor means being responsive to said timing unit and to said user input means and being arranged to enable operation of said locking mechanism (60, 70-78) if the time information provided by said timing unit (28) corresponds to said preset time information and if a user selected code input by way of said user input means corresponds to said preset code.
A security system as claimed in Claim 6, wherein both the preset time information and the preset code are programmable by the user by way of the user input means (8).
A security system as claimed in any preceding claim, further comprising a programming button (20), coupled to said processor means (40), and arranged on actuation to signal to said processor means that stored information is to be changed.
A security system as claimed in any preceding claim, wherein said user input means (8) comprises sensing means arranged to sense a user attempt to open and close the lock, and arranged to signal a user demand to said processor means (40).
A security system as claimed in any preceding claim, wherein the processor means (40) is arranged cyclically to look at the state of the user input means (8), and if the processor means (40) determines that a demand exists for operation of the locking mechanism (60, 70-78), the processor means is responsive to that demand and is arranged to connect battery means (26) to selected parts of the security system to supply electrical power thereto.
A security system as claimed in any preceding claim, wherein said lock (22) comprises one or more locking bolts (4), and said locking mechanism (60, 70-78) comprises means (60) to reciprocate the bolts to open and close the lock.
A security system as claimed in Claim 11, wherein said locking mechanism (60, 70-78) comprises a rotatable knob or a lever (24, 70) coupled to the bolt or bolts (4), and wherein the bolt or bolts (4) are biassed by biassing means to a closed position in which the bolt or bolts are extended, and the bolt or bolts are retractable to an open position by way of the knob or lever against the action of the biassing means.
A security system as claimed in Claim 12, wherein the retraction of the bolt or bolts (4) to open the lock is normally prevented by way of electrically operated means comprising a solenoid (72) arranged, upon energisation, to extend a locking pin (74) such that retraction of the bolt or bolts is thereby prevented.
A security system as claimed in any preceding claim, further comprising storage means (30) arranged to store information relating to the operation of the security system, and connector means (18) arranged to enable a separate external interface device to be coupled to the security system and to receive the stored operational information.
A safe incorporating a security system as claimed in any preceding claim to retain locked a door (2) of the safe.