WO1999014457A1

WO1999014457A1 - A door lock system

Info

Publication number: WO1999014457A1
Application number: PCT/IL1998/000356
Authority: WO
Inventors: Yosi Chen-Zoor
Original assignee: Chen Zoor Yosi
Priority date: 1997-09-16
Filing date: 1998-07-30
Publication date: 1999-03-25
Also published as: AU8558298A; IL121777A0; IL121777A

Abstract

A door locking system comprises a lock with inner locking mechanism controlled by an external access means (9) and a lock attachment module (6) for blocking the inner locking mechanism or releasing thereof. The lock attachment module (6) is controlled electronically and is capable to block or to release the locking mechanism upon identifying and acknowledging the external access means thus providing for additional level of security to the system.

Description

A door lock system

Field of the invention

The present invention relates to a door lock system for ensuring that locking and opening of the door is done only by an authorized person.

More particularly the present invention refers to an auxiliary security device to be mounted on an existing mortise or cylindrical lock for providing an additional level of door lock security.

Background of the invention

There are known various door lock systems to be used with existing locks for improving their security level. The most closed to the present invention prior art includes " Retrofittable electronic and mechanical door system" as per US5437174 to Aydin and "Privacy protection for electronic lock system" as per U5608298 to Frolov.

The system disclosed in the '174 patent includes an electronic socket to removably receive a button-like casing secured on the outside face of a door and carrying an integrated circuit therein. The socket transmits code to a microprocessor based circuit which controls a rotary two-directional motor. The microprocessor unit and the motor reside within a module secured on the inside face of a door. The motor turns a cam which lifts or lowers a frame-like slide provided with a plunger which fits in a cavity of the cylinder to lock or release thereof.

The lock system described in the '298 patent is to be mounted on the opposite sides of a door to provide an electronically operable level of security. On the outside face of the door there is mounted a card reader which upon approving a code of an electronic access device generates a release signal to control the operation of a conventional latch. The latch control mechanism is mounted within a module compartment secured on the inside face of the door and comprises a microprocessor and a motor capable to disengage a locking dog to thereby allow rotation of the latch handle. The motor is actuated by a signal generated by a microprocessor in response to release signal sent by a card reader. The main disadvantage of the prior art modules lies in the fact that their construction is designed for retrofitting to the existing locks since they are based on direct mechanical control of the cylinder by a dedicated locking means This design approach is inevitably associated with the necessity in modification of the lock construction and thus with the complication of the whole lock system. It should be pointed out that once the lock has been modified it can not be used alone without the module Thus, the solutions based on this approach are inherently more expensive and less convenient in installation Moreover, the lock security systems implementing such solutions are less reliable and require more often maintenance

The further disadvantage of the known systems is associated with the necessity in external card reader device for recognizing and approving the code of the electronic access device This reading device is mounted on the external face of the door outside of the door handle The known systems employ a reading device like a socket, key-board, a membrane key pad, eye scanner, a palm reader, etc which should be used with the dedicated electronic access device like a touch key, a magnetic card, etc These reading devices are not suitable for opening the door and therefore a dedicated key means is always necessary It can be readily appreciated that this provision renders the known lock security systems complicated seeing that an additional component, e g a key is required

Objects of the invention

The object of the present invention is to provide for a new and improved door lock system which will sufficiently reduce or overcome the above mentioned drawbacks of the prior art door lock systems

In particular, the main object of the present invention is to provide for a new and improved door lock system which has very simple construction and requires installation only on the inside face of an existing door without any modification of the lock construction or retrofitting thereto

The second object of the present invention is to provide for a new and cheap electronically operable door lock system which does not require an external card reader device and does not need a dedicated electronic access means. Still further object of the present invention is to provide for a new door lock system employing a sole access means which is suitable both for electronic and mechanical control of the lock operation.

The above and other objects and advantages of the present invention can be achieved in accordance with the following combination of its essential features, referring to different embodiments thereof.

The first preferred embodiment of the present invention refers to a door lock system for locking or unlocking a door by means of a lock having an inner locking mechanism and a latch, said locking mechanism being suitable for operation by a key or a knob, wherein rotation of said key or knob is associated with advancing or retracting of the latch and correspondingly with the locking or unlocking of the door, said system comprising in combination a lock attachment module to be mounted on the inside face of the door and an external access means suitable for controlling the module electronically, said module being capable to block said latch in its advanced position so as to provide an additional level of security to the locked door or to release the latch so as to allow retracting thereof and to unlock the door, said module comprising

- an accessible from the outside handle formed with a depression configured so as to enable protruding said knob or said key within said depression, wherein said depression embraces the protruding portion of said knob or said key so as to enable rotation thereof by said handle

- a handle blocking mechanism adapted upon receiving a control signal to engage or to release said handle and correspondingly to prevent or to allow rotation thereof together with said knob or key

- an electronic circuitry capable to establish a communication link between said module and said external access means and to generate a control signal for activating said handle blocking mechanism upon identifying and acknowledging of said external access means

- a source of energy for energizing said circuitry and said handle blocking mechanism. In one of the preferred embodiments said handle is provided with a recess and said blocking mechanism comprises

- a drive means, substantially formed as a bi-directional motor provided with a wormed or toothed wheel shaft. - a transmission member cooperating with said drive means and capable to transform the rotation movement of said shaft into reciprocating linear movement

- a rod movable by said transmission member and capable to enter into said recess or to be removed therefrom depending on the direction of linear movement submitted thereto by said transmission member

In a further preferred embodiment said handle blocking mechanism comprises a compensation means for compensating the weight of the transmission member, said compensation means being for example a pivoting counterbalance In the other preferred embodiment said module is provided with a switching means capable to sense the direction of rotation of said handle and to activate or deactivate said electronic circuitry depending on the direction of rotation In yet another preferred embodiment said module is provided with a dynamo means capable to generate electrical energy for energizing said electronic circuitry and recharging said source of energy In the other preferred embodiment said external access means comprises a key provided with a mechanical coding means and with an electronic circuitry capable of generating an electronic signal and establishing a communication link with said module In the further preferred embodiment said module is provided with a transmitting means capable to transmit to said external access means an activating signal. The present invention in its various embodiments referring to the different groups above has only been summarized briefly

For better understanding of the present invention as well of its benefits and advantages, reference will now be made to the following description of its embodiments taken in combination with the accompanying drawings

Brief description of the drawings

Figs.1 a,b show correspondingly a conventional door with a module mounted thereon and without a module

Fig 2 depicts the module mounted on the inside face of the door and an access means to be inserted in a key hole in the outside face of the door

Fig.3 is an exploded view of the door and a module to be mounted thereon Fig 4 shows the outside face of the door and the inwardly facing side of the module to be mounted on the inwardly facing side of the door

Fig 5 shows the inwardly facing side of the module

Figs 6a,b,c,d present internal structure of the module and its various embodiments

Figs 7,8 show respectively an end view partly broken away, partly in section of a module when attached to the door and an enlarged detail of this cross section

Figs 9a,b show respectively an end view partly broken away, partly in section cross section of an additional embodiment of a module attached to the door and an enlarged detail of this cross section

Fig 10 is a cross section of the module's handle

Fig 11 is a schematic diagram of electπcal and electronic components referring to the module

Fig 12 is an enlarged presentation of an external access means

Fig 13 is a schematic diagram of electronic components referring to an external access means

Detailed description of specific embodiments

With reference to figs la,b it is shown how the door locking system in accordance with the present invention is implemented on a door 1 , which can be locked in closed position by means of a cylinder or mortise lock provided with an inner rotor mechanism (not shown) for operating a retractable latch bolt 2 The latch bolt protrudes from the door and locks thereof once a mechanical key means 3 is turned so as to cause the inner rotor mechanism to push the latch bolt outside As shown in fig lb the key means protrudes outside from a keyhole 4 thus being accessible for manual rotation for operating the lock Furthermore it will be explained how the lock system of the present invention is implemented with a cylinder lock operated manually by rotation of a key and provided with one latch bolt It should be understood however that this system is not limited by the particular type of lock as indicated above and it can be implemented also with locks provided with a knob or any other means protruding from the door and accessible for manual rotation of the inner locking mechanism In the further description a key, or a knob or any other means which protrudes from the inner face of the door and is suitable for rotation of the inner locking mechanism will be referred to as an access means

It should be borne in mind that the locking system of the present invention is not limited by the type of inner locking mechanism and is suitable for locks which employ rotational movement for activation of more than one latch bolt or for activation of one or more dead bolts, bars etc

There is provided also ordinary latch 5, which can be operated by door handles 5 ',5" The locks system of the present invention comprises a lock attachment module 6 to be mounted on the inside face 7 of the door As it will be explained in details further the module is formed as a small, compact, autonomous, stand alone unit, which is provided with all the electromechanical and electronic components necessary either to block the inner locking mechanism when the latch is pushed outside or to release the locking mechanism and thus to allow retracting the latch bolt necessary for unlocking the door It can be realized that by virtue of this provision additional level of security to the locked door is provided.

As shown in figs. 1,2 the module comprises a handle 8, which is accessible from the outside so as to be manually rotated. By virtue of this handle the person within the dwelling or premises can operate the lock so as either to lock the door or unlock thereof For locking or unlocking the door from the outside of a dwelling or premises one should use an external access means formed preferably as a key 9 to be inserted into a keyhole on the outside face 10 of the door The external access means of the present invention is formed preferably as a flat key having elongated shaft portion with projecting therefrom mechanical lock control means schematically shown as notches N The key is provided also with a flat body portion carrying an electronic circuit chip EC capable to receive and transmit an electronically coded identification signal It can be readily appreciated that projecting notches constitute a mechanical coding means of the key, while the electronic circuit constitutes an electronic coding means Once such key is inserted within the keyhole there is established a communication link with the module for identifying the key After the coded signal transmitted by a key has been recognized and acknowledged the module either releases the locking mechanism to permit unlocking the door or blocks the locking mechanism to prevent unlocking the door. The module and the external access means in combination provide for a simple door locking system which does not require for any modification of the existing lock In contrast to the modules described in the prior art systems the present module can be easily mounted on the door without necessity to dismantle the existing lock and without necessity in retrofitting thereto. Seeing that the module is mounted on the inside face of the door it can not be accessed from the outside of the dwelling and therefore there is no possibility for tampering thereof. By virtue of the external access means which can be coded both mechanically and electronically even more security is rendered to the whole system. With reference to fig.3 it will be explained now how the module of the present invention can be easily and conveniently mounted on the door The module comprises a casing 11 and a base plate 12 with residing thereon various electromechanical and electronic components necessary for functioning the module The base plate is secured on the inside face of the door by a couple of mounting screws 13,13', passing via a couple of through-going openings 14.14' made within the base plate. The screws are screwed into a couple of corresponding threaded bores 15, 15 'made within the door It is especially convenient to use for this purpose the same bores and mounting screws which are already available for mounting the outside plate 16 of the existing lock. There are provided also screws for securing the casing on the lateral sides of the base plate once the latest is mounted on the door. As seen in fig 4 a circular window 17 is made in the base plate for mounting the handle 8 with possibility for rotation with respect to the base plate. The handle is formed with a tail portion 18 protruding from the base plate towards the round opening 19 formed in the casing so as to be accessible from the outside. The opposite extremity of the handle is formed as a circular portion 20 facing towards the door Within the circular portion of the handle there is made a depression 21 which cross sectional configuration conforms the shape of the access means protruding from the lock. The depth of depression 21 exceeds the length of the protruding portion of the access means. By virtue of this provision it is possible to put the handle on the protruding portion of the access means and thus to attach the base plate to the inside face of the door. Seeing that the access means resides wholly within the depression and is closely embraced thereby the handle is rotated together with the access means and thus the rotation movement can be transferred to the locking mechanism Now the module's construction will be explained in more details As is best seen in figs 5, 6a and 8 the base plate is provided with two lateral compartments L1,L2 and with intermediate compartment I situated therebetween Within the intermediate compartment reside the main components of the module a handle blocking mechanism 22 and a plate 23 with residing thereon electronic circuitry 23' for controlling the module functioning. There is provided a source of energy for energizing the circuitry and the handle blocking mechanism The source of energy is shown schematically as plurality of alkaline batteries 24 disposed within lateral compartments of the base plate The handle blocking mechanism consists of a bi-directional DC motor 25 having wormed or toothed output shaft 26 meshing with opposite teeth 27,28 of a U-shaped anvil member 29 The motor is wired by a wiring W with the electronic circuitry which controls its operation The anvil member is mounted within parallel slides 30,31 with possibility for linear reciprocating movement along the slides It can be readily appreciated that when the motor is energized and rotates its shaft the teeth 27,28 mesh therewith and force the anvil member to move linearly along the slides up or down depending on the direction of rotation Disposed above the anvil member a rod 32 is provided The rod is closed by a cover plate 33 with possibility for linear movement with respect thereto As best seen in fig 8 the output shaft 26 of motor 25 resides within the lower part of the anvil member Rod 32 is connected with the upper part of the anvil member by virtue of a L-shaped portion 32' entering into a central portion 43 of the anvil member By virtue of this provision the rod is driven upwardly or downwardly by the anvil member when it respectively slides up or down In order to reduce the power required from the motor for advancing the anvil member there is provided a pivoting counterbalance 34 The pivoting axis of the counterbalance resides within the slides and the opposite extremity 34' of the counterbalance is inserted within the dedicated opening 44 made in the anvil member Seeing that the counterbalance is linked with the anvil member its weight is compensated and therefore the power required from the motor to move the anvil member should be sufficient only to overcome the friction between the anvil member and slides It is not shown specifically but should be understood that alternative compensating means can be employed as well For example instead of a pivoting counterbalance one can use spring loaded mechanism or the like With reference to figs 8, 10 a flange member 46 is provided for mounting the handle on the base plate The circular portion 20 of the handle resides within an annular recess 47 made in the flange The inside diameter of recess 47 slightly exceeds the outside diameter of circular portion 20 and thus it is possible to rotate the handle within the flange The width H of the annular recess exceeds the width h of the circular portion and thus it is possible to displace the handle linearly within the flange so as to push it inwardly towards the base plate

A recess 35 is made within circular portion 20 of the handle to receive the upper extremity of the rod when it is pushed up by the anvil member The recess is accessible by virtue of the dedicated window 48 made in the flange member It can be appreciated that once rod 32 is pushed into recess 35 it prevents rotation of the handle and thus operating of the inner locking mechamsm is blocked In order to release the handle and to operate the locking mechanism the rod should be removed from the recess For this purpose the motor is energized and rotates in the opposite direction so as move anvil member 31 down and to retract rod 32 from recess 35 This situation is presented in fig 6b In fig 6c is shown the situation corresponding to the upper position of rod 32 after it has been lifted by the anvil member in the upper position to block the handle By virtue of the fact that motor 25, anvil member 29 and rod 32 are separate elements the jamming of the motor is prevented once the rod is stuck in recess 35 after the handle has been turned too fast

As shown in fig 6a plurality of micro switches SW1, SW2, SW3 surround the flange member 46 Micro switch SW1 is responsible for advising the electronic circuitry that handle 8 is being manually operated for locking or unlocking the door from the inside of the dwelling and that there is no need for acknowledging the external access means before energizing the motor As shown in fig 10 the micro switch SW1 is provided with a pin P capable to access the periphery of the handle's circular portion via a dedicated opening made in the flange member

Micro switches SW2 and SW3 are responsible for identifying the direction of rotation of the handle i e whether the door should be locked or unlocked These micro switches are provided with appropriate contact sensors, e g reed switch sensors which are capable to sense the rotation of the handle and to pass this information to the electronic circuitry, which accordingly activates the motor The sensors contact the handle's circular portion via a window 48 made within the flange member The particular disposition of micro switches SW2,SW3 around the handle's circular portion is chosen so as to detect the direction of rotation Depending on this direction the electronic circuitry energizes the motor so as to allow its rotation either clockwise or counterclockwise in order either to push rod 32 within recess 35 or to retract it therefrom

It should be appreciated that alternative sensors of both the contact or non-contact type might be suitable for this purpose as well

With reference to fig 6d it is shown an additional embodiment of the module comprising a dynamo means for utilizing the rotary movement of the handle and transferring thereof into electrical energy This energy can be used for example for the recharging of batteries 24 or for the energizing of electronic circuitry 23 In this embodiment the rotational movement is transferred by a handle's periphery to a first couple of meshing gears 5 ,36'and through an axle 37 to a second couple of meshing gears 38,38', which are connected to the motor It can be realized that when the handle is manually rotated the rotation motion is transferred to the motor and it functions as a generator to produce electrical energy

As shown in fig 7 module 6 is attached to the inner face 7 of the door and it is seen that the protruding therefrom mechanical key means 3 wholly resides within depression 21 of handle 8 It is not shown specifically in fig 7 but should be appreciated that protruding portion of the key is closely embraced by the inwardly facing walls of depression 2 land thus the key is driven by the handle once it is rotated A coil spring 39 is placed within the handle between the rear extremity of the key and the bottom of the depression The spring is capable to return the handle back when it has been pushed inwardly towards the door The significance of this action will be explained further in connection with the operating of the module

A signal transmission element 45 is disposed between the module's base plate 12 and lock's external plate 16 The transmission element is responsible for transmitting a signal to external access means 9 so as to energize thereof and to establish a communication link therewith This element can be formed for example as an inductive coil attached by any suitable method to the door and electrically connected with the module's electronic circuitry The particular disposition of the transmission element should be chosen so as to enable reliable signal transmission In those cases when the door is made of wood the inductive transmission element can be disposed on the door's internal face If however the door is made of metallic material it might be advantageous to dispose the inductive transmission element on the outside face of the door so as to ensure its proximity to the external access means

With reference to figs 9a,b there is shown an additional embodiment of the present invention in which module 6 is attached to the door provided with a knob 40 protruding from the door's locking mechanism As in the previous embodiment the knob wholly resides within the handle being embraced by a depression 21', made in the handle It is advantageous to secure the handle on the knob for example by a couple of screws 41,42 so as to ensure reliable mutual rotation of the knob simultaneously with the handle Disposed between the knob and the bottom of depression 21 'a coil spring 39' is provided so as to return the handle back once it has been pushed inwardly An inductive signal transmission element 45' is disposed between the module's base plate 12 and the lock's external plate

With reference to fig 11 the module's main electrical and electronic components include the following elements a micro controller unit 48, a power supply regulating unit 49 and a communication unit 50 Besides of the above main units there are also provided various auxiliary units, like a real time clock unit 51, a microprocessor EEPROM unit 52, a watch dog timer unit 53, a motor driver unit 54 and an auxiliary EEPROM unit 55 The auxiliary EEPROM unit is intended to memorize the system parameters after the system is switched off The capacity of the auxiliary EEPROM unit should be at least 2-4 kbytes

Most of the above electronic elements is formed as printed electronic circuit board residing on the plate 23 within the module

The watch dog timer unit is responsible to reset the micro controller's processor if there were any interruptions during the running of processor's programs The motor driver unit is responsible for detecting and memorizing the current position of rod 32 This is necessary for avoiding possible malfunction for example when the batteries are replaced and the module is activated from the very beginning The micro controller unit includes an internal RAM block with capacity of 128 bytes The power supply regulating unit is capable to supply DC voltage of 5 v as required for functioning of various digital components, 12 v as required for functioning of the communicating unit and 3 v as required for functioning the real time clock unit The power supply regulating unit also includes a voltage detector 56 for checking whether the voltage supplied by replaceable batteries 24 is not less than 3 3 v and a power switching regulator 57 which upon the condition of micro switch SW1 should turn off or on the power supply Also provided aside from the above listed components are a connector 58 for the outside DC power supply, a reserve switches unit 59 for optional functions if required, a couple of LED indicators 60,60', a buzzer 61 and a port 62 for communication with an external PC unit if required The LED indicators include one green indicator 60, which is lit for 10 sec if the motor is activated for blocking or releasing the handle The second LED indicator 60 'is red It is lit for 5 sec if there is any malfunction or starts blinking for 30 sec if the voltage supplied by batteries is lower than required The buzzer is activated during locking or unlocking the door or when there is system malfunction, or the voltage supplied by batteries is lower than required

Module's communicating unit 50 generates signals which are transmitted by signal transmission element 45 to external access means 9 for energizing thereof and for establishing a communication link therewith

With reference to figs 12,13 there is shown an external access means formed as a mechanical key provided with various electronically controlled means Those means render the key an additional level of security by virtue of capability for electronic communication and coding The electronically controlled means are formed as an electronic circuit chip 63 deposited within a rear extremity 64 of the key The frontal extremity of the key is provided with conventional mechanical means, e g notches, suitable for controlling the tumblers of the internal locking mechanism The key's electronic circuit has its own antenna means formed for example as an inductive coil 65 which is capable to receive an external signal transmitted from the module The external access means is provided also with appropriate electronic components capable of generating coded signals and transmitting them to the communicating unit of the module. These components include for example a controller 66 capable to execute a constant program, which controls the key functioning An analog unit 67 is provided, which is capable to enter the antenna in resonance and thus to reduce the amount of power required for receiving signals transmitted from the module The electronic circuit also includes a bi-rate generator 68, a read-write decoder 69, a modulator 70, an EEPROM unit 71, a generator 72 and an internal power supply 73 In accordance with the present invention the communicating unit 50 is programmed to respond only after the correct code has been transmitted to the module by the key's antenna After the correct code signal has been recognized and acknowledged by the module's electronic circuitry it will energize and activate the motor In order to provide the system of the present invention with an even higher level of security the module's communicating unit can be programmed so as to automatically generate a new random code after each access The new code is transmitted by the communicating unit to the external access means and replaces the old code

Having described the structure of the door lock system of the present invention it will be explained now how it functions in various modes of operation

Two modes of operation should be distinguished The first one is associated with the operating of the module from the dwelling without using the external access means In this situation the closed door can be locked or unlocked depending on the direction of rotation of the handle The second situation is associated with operating the module from outside with the aim of external access means

In the situation when the door should be locked from inside of the dwelling the handle should be pushed against coiled spring 39,39'and then manually rotated in the clockwise direction The pushing action is sensed by micro switch SW1 and causes him to advise the electronic circuitry that the motor can be activated without establishing a communication link with the external access means and acknowledging thereof The rotating action is sensed by micro switches SW2, SW3 and causes them to advise the electronic circuitry that the motor should be activated to rotate the shaft in the direction required for advancing the rod into recess 35 The door is locked and the handle is prevented from being rotated After the door is locked the handle is returned in the initial position by the coil spring

In the situation when the door should be opened from inside of the dwelling the handle should be pushed against coiled spring 39,39'and then manually rotated in the anti clockwise direction The pushing action is sensed by micro switch SW1 and causes him to advise the electronic circuitry that the motor can be activated without establishing a communication link with the external access means and acknowledging thereof The rotating action is sensed by micro switches SW2, SW3 and causes them to advise the electronic circuitry that the motor should be activated to rotate the shaft in the direction required for retracting the rod from recess 35 so as to release the handle The handle can be rotated further to unlock the door and then it is returned by the coil spring in its initial position.

In the situation when the door should be unlocked from outside of the dwelling the external access means should be used The access means is inserted in the key hole and is manually rotated first for 90 degrees in the anti clockwise direction The rotating action is transferred to the handle and sensed by micro switches SW1,SW2 causing them to advise the electronic circuitry to transmit an activating signal to the access means and to energize thereof In response the external access means generates and transmits a coded identification signal to the module Once this identification signal is recognized and acknowledged by the module the motor is activated to rotate the shaft in the direction required for retracting the rod from recess 35 so as to release the handle Now the handle is not blocked any more and further rotation of the external access means is permitted until the door is unlocked.

In the situation when the door should be locked from outside of the dwelling the external access means should be used The user inserts external access means in the key hole and rotates it for at least 360 degrees in the clockwise direction so as to lock the door The rotating action is transferred to the handle and sensed by micro switches SW1,SW2 causing them to advise the electronic circuitry to transmit an activating signal to the access means and to energize thereof In response the external access means generates and transmits a coded identification signal to the module Once this identification signal is recognized and acknowledged by the module the motor is activated to rotate the shaft in the direction required for pushing the rod into recess 35 so as to block the handle Now the door is locked and the locking mechanism can not be rotated by a mechanical key unless valid external access means having electronic coding means is used

It will be appreciated that installation of the module in accordance with the present invention improves the security level of the existing locks without any modification of the existing lock or the door The module itself is simple and can be easily attached to the door irrespective of the type of existing lock It will be also appreciated that the present invention is not limited to the above-described embodiments and that changes and modifications can be made by one ordinarily skilled in the art without deviation from the scope of the invention as will be defined below in the appended claims.

The features disclosed in the foregoing description, and/or in the following claims, and/or in the accompanying drawings may, both separately and in any combination thereof, be material for realizing the present invention in diverse forms thereof.

Claims

1 A door lock system for locking or unlocking a door by means of a lock having an inner locking mechanism and a latch, said locking mechanism being suitable for operation by a key or a knob, wherein rotation of said key or knob is associated with advancing or retracting of the latch and correspondingly with the locking or unlocking of the door, said system comprising in combination a lock attachment module to be mounted on the inside face of the door and an external access means, said module being capable to block said latch in its advanced position so as to provide an additional level of security to the locked door or to release the latch so as to allow retracting thereof and to unlock the door, said module comprising

- an accessible from the outside handle, said handle being formed with a depression configured to allow protruding said knob or said key into said depression, wherein said depression embraces said knob or said key so as to enable rotation thereof by said handle - a handle blocking mechanism adapted upon receiving a control signal to block or to release said handle and correspondingly to prevent or to allow rotation thereof together with said knob or key

- a source of energy for energizing said circuitry and said handle blocking mechanism

2 A door lock system as defined in claim 1, in which said handle is provided with a recess and said blocking mechanism comprises - a drive means, substantially formed as a bi-directional motor provided with a wormed or toothed wheel shaft,

- a transmission member cooperating with said drive means and capable to transform the rotation movement of said shaft into reciprocating linear movement

- a rod movable by said transmission member and capable to enter into said recess or to be removed therefrom depending on the direction of linear movement submitted thereto by said transmission member.

3. A door locking system as defined in claim 2, in which said handle blocking mechanism comprises a compensation means for compensating the weight of the transmission member, said compensation means being for example a pivoting counterbalance.

4. A door lock system as defined in claim 3, in which said module is provided with a switching means capable to sense the direction of rotation of said handle.

5. A door lock system as defined in claim 1, in which said module is provided with a dynamo means capable to generate electrical energy for energizing said electronic circuitry and recharging said source of energy.

6. A door lock system as defined in claim 1, in which said module is provided with a transmitting means capable to transmit to said external access means an activating signal and said external access means comprises a key provided with a mechanical coding means and with an electronic circuitry capable upon receiving said activating signal to generate and transmit to said module an identification signal.