The present invention relates to locking systems and, in particular, to an electrical lock which has both fail safe and fail secure rnechanism inbuilt therein. It will be convenient to describe the invention with particular reference to its use with doors, however it is to be understood that the invention has other uses. BACKGROUND ART

Some secure premises need to keep their doors locked at all times, and use card readers, placed on the entrance and exits of doors, to create an audit trail of people entering and exiting the premises.

A common prior art locking system 10 is shown in Fig. 1 and comprises three separate locks including a fail safe magnetic lock 12 on the top of the door 14, a fail secure electric strike 20 in the door frame 22, and a mechanical lock 16 in the door 14.

The electric strike 20 is an access control device used for door 14. Like a fixed strike, it normally presents a ramped surface to the locking latch allowing the door to close and latch just like a fixed strike would. However, the ramped surface of an electric strike 20 can, upon command, pivot out of the way of the latch allowing the door to be pushed open from the outside, without the latch being retracted {that is, without any operation of the handle 28 shown in Fig. 2).

An electric strike 20 generally comes in two basic configurations: 'fail- secure' or 'fail-safe'. In the fail-secure (also called 'fail-locked' or 'non-fail safe') configuration, applying electrical current to the electric strike 20 will cause it to unlock. In this configuration, the electric strike 20 would remain locked in a power failure, but typically the handle 18 can still be used to open the door 14 from the inside for egress from the secure side. These units can be powered by AC which will cause the unit to "buzz", or DC power which will offer silent operation, except for a "click" while the unit releases. In the fail-safe (also called 'fail-open') configuration, applying electrical current to the strike 20 will cause it to lock. In this configuration, it operates the same as a magnetic lock would. If there is a power failure, the door would open merely by being pushed/pulled open.

The magnetic lock 12 is a simple locking device that consists of an electromagnet and armature plate. By attaching the electromagnet to the door frame and the armature plate to the door, a current passing through the electromagnet attracts the armature plate holding the door shut. Unlike the electric strike 20, the magnetic lock 12 has no abutting parts and is therefore not suitable for high security applications because it is possible to bypass the lock by disrupting the power supply. Nevertheless, the strength of today's magnetic locks compare well with conventional door locks.

The prior art locking system also comprises the mechanical lock 16. The mechanical lock 16 is adapted so that the handle 18 on the inside of the door 14 (shown in Fig. 1) can be turned to allow egress from the secured premises, but the handle 28 cannot be turned from the outside of the door 14 (shown in Fig. 2).

The handle 28 does not need to be turned to enter the premises because the ramped surface of an electric strike 20 pivots out of the way of the latch, allowing the door to be pushed open from the outside without the latch being retracted, when a valid card is inserted in the card reader 25, which deactivates the magnetic lock 12 and the electric strike 20. A release unit 26 comprising a breakable glass pane is installed near the exit of the secure premises. When the power to the building is dropped during an emergency (for example, a fire) or when the release unit 26 is activated, the fail safe magnetic lock 12 unlocks and the fail secure electric strike 20 locks. In this event, the electric strike 20 permits people to exit from the secure premises, but not to enter the premises, even if a valid card is inserted into the card reader 25.

There is a need for a locking system which is able to subsume the fail safe and fail secure functions of the electric strike and magnetic lock within one device.

It is a further object of the invention to provide a single device for use in a door that has both fail safe and fail secure functionality that does not require additional locks to be employed in the door frame.

DISCLOSURE OF INVENTION According to the present invention there is provided an electrical lock including:

- a fail safe mechanism operable on the opening means of the inside of the door to a secure premises and

- a fail secure mechanism operable on the opening means on the outside of the door to the secure premises, wherein, in the electrical event of a power failure to the electrical lock, the door can be opened from the inside but not from the outside. Preferably, the opening means comprises a door handle. It is also preferred that the electrical lock comprises an electrical mortise lock. In a preferred embodiment, the electrical mortise lock comprises:

- a first actuator operable on the inside door handle such that when power is withdrawn from the first actuator, the inside handle can still be operated and the door opened, and - a second actuator operable on the outside door handle such that when the power is withdrawn from the second actuator, the outside handle cannot be operated to open the door. Preferably, the electrical lock is adapted to be unlocked via sensors located on the inside and outside of the door to the secure premises. Preferably the electrical lock is adapted to be unlocked using one or more sensors by connecting the electrical lock to a controller which receives signals from the one or more sensors, the signals causing the controller to provide or cut power to the electrical lock's actuators which either opens or locks the door. More preferably, the one or more sensors are adapted to sense any one of traditional metal keys, magnetic cards, biometric information or radio- frequency identification.

It is preferred that the electrical lock is further adapted to operated by a release unit located on the inside of the secure premises and connected to the controller, so that when the release unit is activated, the controller provides or cuts power to the actuators which allows a person to exit from the secure premises without the need to use a key.

In a preferred embodiment, the electrical mortise lock is adapted to be operated remotely by the operation of one or more remote control units where they communicate with the controller which provides or cuts power to the actuators to facilitate or prevent the opening of the door. It is also preferred that the electrical lock includes one or more of the following functions:

- a manual key override

- manual key override monitor; - a hub monitor;

- a status indicator (LED).

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the invention may be readily understood and put into practical effect, reference will now be made to the accompanying drawings, in which:

Fig.1 shows a prior art locking system on the inside of secure premises;

Fig. 2 shows the prior art locking system of Fig. 1 on the outside of the secure premises;

Fig.3 shows a locking system according to a preferred embodiment of the present invention, on the inside of the secure premises;

Fig. 4 shows the locking system of Fig. 3, on the outside of the secure premises;

Fig. 5 shows a schematic view of the electrical lock of Figs. 3 and 4. MODES FOR CARRYING OUT THE INVENTION The electrical lock 30 of the present invention, shown generally in Figs.

3 and 4, eliminates the need for a fail safe magnetic lock 12 and the fail secure electric strike 20 (see Figs. 1 and 2).

A mortise lock is one that requires a pocket, known as a 'mortise', to be cut into the door frame 22 into which the lock is to be fitted. As shown in Fig. 5, the electrical lock 30 comprises a fail safe actuator

32 which permits the rotation of the internal handle 18 (see Fig. 3) when power is disconnected from the electrical lock 30, and a fail secure actuator 34 which prevents the rotation of the external handle 28 (see Fig. 4) when power is disconnected from the electrical lock 30.

In one embodiment the latch bolt 40 of the electrical lock 30 is connected to the external handle 28 via a series of intermediary components that transfer the rotational movement of the handle 28 into a horizontal movement of the latch bolt 40. Operable on either the latch bolt itself, but preferably on one of the intermediary components that transfer the movement from handle 28 to latch bolt 40 are the fail safe actuator 32 and the fail secure actuator 34. The fail safe actuator 32 is connected to the electrical lock 30 such that when energised the fail safe actuator 32 prevents the rotation of the handle 28 from being translated into movement of the latch bolt 40 by restraining from movement one or more of the intermediary parts of the electrical lock 30 that it is connected to. The fail secure actuator 34 is connected to the electrical lock 30 such that when energised the fail secure actuator allows the rotation of the handle 28 to be translated into horizontal movement of the latch bolt 40, and when de-energised, prevents the rotation of the handle 28 from being translated into movement of the latch bolt 40 by restraining from movement one or more intermediary parts of the electrical lock 30 that it is connected to. The electrical lock 30 is electronically controlled by controller 36 which is connected to the electrical lock by cable 38, and which is in electronic communication with one or more of the following:

- sensors such as magnetic card readers 24 and 25, traditional keyholes for metal keys key (where the turning of the key in the device outputs an electrical signal for input into the controller 36), radio- frequency identification tag sensors, biometric sensors, and other sensors used for authenticating identity; - a release unit 26 for cutting power to the fail safe actuator 32 to allow people to exit from the secure premises during an emergency, without the need to use a key;

- other remote control units for remotely operating either fail safe actuator 32 or fail secure actuator 34 from a remote position.

When a valid card is inserted into the magnetic card reader 24 on the inside of the secure premises, the card reader 24 sends a signal representative of the data contained on the card to the controller 36 whereupon the signal is processed to identify the card, and if authorised for access, power is supplied by the controller to the fail secure actuator 34 and also, power is cut from the controller to the fail safe actuator 32. This allows the handle 28 to be turned on either the inside or outside of the door.

When a valid card is inserted into the magnetic card reader 25 on the outside of the secure area, the card reader 25 sends a signal representative of the data contained on the card to the controller 36 whereupon the signal is processed to identify the card and if authorised for access power is supplied by the controller to the fail safe actuator 32 and also, power is cut from the controller to the fail secure actuator 34. This allows the handle 28 to be turned on either the inside or outside of the door. !n an alternative embodiment of the invention the lock provides an LED indicator which indicates the state of the lock. In a preferred embodiment, green indicates unlocked and red indicates locked.

A further embodiment of the invention provides for a manual key override function provided by the inclusion of a manual mortice lock in the electrical lock 30, whereupon the user can at all times open the door using a key for the manual mortice lock. Alternatively, the key can be used to lock the electric lock such that no access is granted to anyone other than a possessor of the manual override key. This embodiment further comprises monitoring and reporting means for identifying when the manual key override function is utilised. The monitoring means can be provided by contact switches that operate on the turning of the key to provide an electrical output which is received by the controller 36.

Further embodiments of the invention provide hub monitoring which is provided by means of various tampering sensors inserted into and around the lock in the door such that any attempts at tampering with the locking assembly 30 will result in signals being sent to the controller 36. Various modifications may be made in the details of design and construction without departing from the scope and ambit of the invention, for instance the invention has been described by reference to a lock for a door, but a person skilled in the art would appreciate that the present lock has uses beyond use in a door, for example, a gate or hatch.