GB2169649A - Lock and key and method of operating a lock - Google Patents

Abstract

A lock and latch set for a door includes a cylinder lock (10) which drives the latch bolt (2) through a clutch (55). Insertion of the proper key moves tumblers (24) to releasing positions and the key can then be turned to retract the latch bolt (2), A binary encoded number is read from the key by a reader which includes followers (28,29,38,39) for engaging formations on the key. If an acceptable code is not read during insertion of the key, the clutch is set in a non-driving condition. <IMAGE>

Description

SPECIFICATION Lock and key and method of operating a lock In GB 1,467,891, there is proposed a lock having a key reader for reading a digitally encoded access enabling code recorded on a key, when the key is inserted into the lock. It is also proposed that an access enabling signal is generated when there is read from the key either one of two alternative acceptable codes. It is indicated that the access enabling signal serves to initiate actuation of a solenoid, or the like, releasing the lock mechanism to afford room access to the possessor of the key. The proposed arrangement may be satisfactory in a case where power for operation of the lock is obtained from a mains supply.

However, the proposed arrangement is less suitable for use in a case where the power for operation of the lock is to be provided by a battery contained in the lock. A solenoid for releasing a lock mechanism has a very high power rating, as compared with the power rating of electronic components which can be used for reading the code from the key. Energisation of the solenoid on each occasion when access is required to the room would quickly exhaust a battery of modest capacity.

The provision of large capacity batteries would be inconvenient and expensive.

According to a first aspect of the invention, there is provided a combination comprising a key bearing information, a moveable key-receiving member, reading means for reading said information from the key when the key is applied to said member and providing an electrical signal representing said information, an associated device which can be operated by movement of the key-receiving member by means of the key and control means for controlli ng operation of the associated device by movement of the key-receiving member, wherein the control means is arranged to disable the combination if the reading means fails to read acceptable information upon application of a key or like instrument to the keyreceiving member so that operation of the associated device by movement of the key-receiving member by means of an instrument which does not bear information acceptable to the control means is prevented.

The control means may disable the combination by interfering with the transmission of force from the key-receiving member to the associated device or by restraining movement of the key-receiving member. The associated device may be a bolt or other fastener, an electrical switch or other flow-control means.

The control means of a combination in accordance with the first aspect of the invention preferably includes a normally de-energised electrically energisable element which, when energised, disables the combination. Since the element is normally de-energised, it does not normally consume electrical power. Furthermore, the element will remain de-energised if there is applied to the key-receiving member a proper key from which information acceptable to the control means is read. Electrical power is used only if an attempt is made to operate the associated device by an improper implement.

The preferred combination further includes a locking element movable by means of the key, when applied the key-receiving member, between a locking position in which the element obstructs movement of the key-receiving member and a releasing position in which it does not substantially obstruct movement of the key-receiving member. The locking element may be a tumbler of known form and generally a plurality of such locking elements will be provided. The key may engage the locking elements directly. Alternatively, the key may act remotely on the locking elements, for example by means of a magnetic field of the key.

The information to be read by the reading means is preferably represented on the key by formations, by which we mean features of shape of the key. Alternatively, the information may be represented on the key by a magnetic field associated with the key, by light and dark areas or transparent and opaque areas or in some other manner which facilitates reading of the information from the key by radiation.

According to a second aspect of the invention, there is provided a lock comprising first and second locking means, each being capable independently of the other of establishing a secure condition of the lock, wherein the first locking means is adapted for direct actuation by a key, when the key is applied to the lock and, in the absence of the key, the first locking means automatically establishes the secure condition, the lock further comprising reading means for reading data from the key and providing an electrical signal representing said data, key-detector means for providing a keyentry signal upon application of the key to the lock and control means operatively associated with the second locking means for causing same to establish the secure condition after the key-entry signal has been provided, unless a predetermined set of data or one af a plurality of alternative predetermined sets of data has been read from the key within a predetermined period commencing when the key-entry signal is provided.

The secure condition may be a locked condition, in which a member of the lock or of an associated device which is to be moved during operation of the lock is locked against movement. The secure condition may also be a condition in which the lock is incapable of transmitting drive from an operator to an associated device which is to be controlled by the lock.

According to a third aspect of the invention, there is provided a lock comprising a body, a key-receiving member mounted for movement relative to the body, an output element movable relative to the body with the key-receiving member when the proper key is applied thereto, reading means for reading information from a key when applied to the key-receiving member, disabling means and control means for controlling operation of the disabling means, wherein the control means and disabling means are arranged to disable the lock if the reading means fails to read acceptable information upon application of a key or like instrument to the key-receiving member so that movement of the output element relative to the body by means of an instrument which does not bear information acceptable to the control means is prevented.

The lock may further comprise transmission means for transmitting drive between the keyreceiving member and the output element, the transmission means being settable in a selected one of a driving condition and a nondriving condition by the disabling means. The disabling means is preferably electrically energisable. The transmission means is preferably arranged to remain in the selected condition whilst the disabling means is not energised.

The output element may be used for controlling or driving a bolt or latch. When the transmission means is in the driving condition, drive can be transmitted to such an associated device from an operator via a key inserted in the key-receiving member.

Setting of the transmission means from one condition to the other condition can be achieved with a relatively small expenditure of electrical energy.

The disabling means may comprise a solenoid or other form of electro-magnet however, the disabling means preferably comprises a pair of solenoids arranged one for setting the transmission means from the driving condition to the non-driving condition and the other solenoid being arranged for setting the transmission means from the non-driving condition to the driving condition.

According to a further aspect of the invention, there is provided a method of preventing the use by unauthorised persons of a device having a movable driven member wherein there is combined with the device a key-receiving member, reading means for reading information from a key when applied to the key-receiving member and control means for controlling use of the device, the key-receiving member being arranged for movement by means of the proper key, when applied thereto, and for transmitting drive to said driven member, wherein, as a consequence of application to the key-receiving member of an instrument other than a proper key but which is capable of moving the key-receiving member, the combination of said device and keyreceiving member is disabled so that operation of the device by movement of the key-receiving member by said instrument is prevented.

An example of a fastening device embodying the present invention will now be described, with reference to the accompanying drawings, wherein: FIGURE 1 shows a cross-section in a vertical plane through a doorfastening device incorporating a lock; FIGURE 2 shows a cross-section of the lock in a plane containing an axis of the lock, and showing the shank of a key present in the lock; FIGURE 3 shows a cross-section on the line Ill-Ill of Figure 2; FIGURE 4 shows a cross-section on the line IV-IV of Figure 2; FIGURE 5 shows parts of the lock, as viewed in the direction of arrow V of Figure 3.

FIGURE 6 is a front view of the device, partly broken away to reveal internal parts; FIGURE 7 shows certain parts of the device, as viewed in a vertical plane perpendicular to the plane of Figure 1; FIGURE 8 is a cross-section on the line VIII VIII of Figure 7, and FIGURE 9 is a diagrammatic perspective view of certain parts of a modified version of the device shown in Figures 1 to 8.

The device shown in Figures 1 to 8 of the accompanying drawings is a lockable fastener suitable for fastening the door to a room or other enclosure. The fastener includes a body 1 which is mounted in the door and in which there is mounted for reciprocation along a rectilinear path a latch bolt 2. The latch bolt can move between a projected position, shown in Figures 7 and 8, and a retracted position, in which the latch bolt is withdrawn substantially completely into the body 1. The body may comprise separable parts, one of these being a tubular housing for the latch bolt. A spring 3 is provided for urging the latch bolt towards its projected position. For moving the latch bolt towards its retracted position, there is provided a handle 4 which is accessible at the inner face of the door and a lock 10 which is accessible at the outer face of the door.

The lock 10 shown in the drawings comprises an outer housing 1 1 comprising a generally cylindrical and relatively short outer end portion 12., defining an axis 13 of the lock, an intermediate porton 14 which is offset radially with respect to the axis 13 and is longer than the outer end portion and an inner end portion 15 which is also considerably longer than the outer end portion. From the inner end portion 15, there protrudes a driving member 16 which, when the key is present in the lock, is movable angularly relative to the outer housing 1 1 about a cylinder axis 17 parallel to but off-set from the lock axis 13.

Transmission means 50 is provided for transmitting drive to the latch bolt 2 from the driving member 16. The transmission means includes a toothed sector 51 mounted in the body 1 and arranged for driving a rack 52 on the latch bolt. The sector is formed on a sleeve 53 rotatably carried on a shaft 54. A clutch 55 is provided for selectively coupling the shaft 54 and sleeve 53. The axis of the shaft 54 coincides with the cylinder axis 17 and the shaft is drivingly engaged in a socket of the shaft by the driving member 16 so that the shaft can be turned by the driving member. When the clutch 55 is in a driving condition, the sector 51 can be turned by the driving member 16 to withdraw the latch bolt to its retracted position. When the clutch is in a non-driving condition, turning of the member 16 does not cause movement of the latch bolt.

The lock 10 further comprises a key-receiving member 21 which defines an elongate keyway along which the cylinder axis 17 extends. The cross-sectional shape of the keyway in a plane perpendicular to that axis is a rectangle. The radially outer surface of the key-receiving member is generally cylindrical and this member is received in a cylindrical opening defined by the outer housing 1 1, thereby being mounted for rotation relative to the outer housing about the cylinder axis 17.

The outer housing is trapped between a circlip 22 on an inner end portion of the member 21 and a flange 23 at the outer end of the same member. The driving member 16 is integral with or is fixed with respect to the key-receiving member.

A number of tumblers are provided for restraining rotation of the keyreceiving member 21 relative to the outer housing 11, when the correct key is absent from the keyway of the lock. These tumblers may be disc tumblers or pin tumblers and may be arranged in a known manner. By way of example, there are shown in the drawings four pin tumblers, two of which are identified by the reference numeral 24. The inner end portion 15 of the outer housing constitutes a tumbler housing in which respective parts of the tumblers are received and which contains springs biasing the tumblers to respective locking positions in a known manner.

The key shank 25 has a rectangular crosssection in a plane perpendicular to the cylinder axis 17 and is a sliding fit in the keyway. End portions of the tumblers project through respective openings in the keyreceiving member 21 into the keyway to engage respective formations on an edge of a key shank when the latter is present in the keyway. These formations are arranged to hold the tumblers in respective releasing positions. At least one of these formations differs from others of these formations.

The key shank has further formations which represent data identifying the key. In the example illustrated, these further formations are provided at the major faces of the key shank and are substantially identical circular recesses with gently inclined sides, as can be seen in Figure 3. The further formations are arranged in rows extending along the key shank, that is in a direction parallel to the cylinder axis 17 when the key shank is in the key way. In the example illustrated, there is on one major face of the key a first row of recesses 26, called herein the clock track, and a second row of recesses 27, called herein the data track.

The recesses 26 of the clock track are arranged at a uniform pitch along the key shank.

The number of recesses in the data track is smaller than the number of recesses in the clock track and the recesses 27 occupy certain only of a number of sites along the clock track which are at the same pitch as are the recesses of the clock track. The recesses 27 represent in binary form a number identifying the key.

The other major face of the key may be provided with a clock track and a data track similar to or identical with those shown in Figure 2. The recesses 26 of the clock track shown in Figure 2 may be spaced somewhat further apart than shown in the drawings, recesses of the clock track on the other major face of the key occupying positions corresponding to those of gaps between the recesses 26. Similarly, recesses of a data track on the other major face of the key may be off-set along the track with respect to the recesses 27.

The lock 10 includes reading means for reading data from the data tracks of the key.

The reading means includes a follower for each data track and, since in the example illustrated there are two data tracks on the key shank, two followers, 28 and 29, are provided. These followers are mounted in the key-receiving member 21 at opposite sides of the key slot for reciprocation towards and away from each other. Penetration of the followers into the keyway is limited by engagement of the followers with the key-receiving member and each follower has a length such that, when one end portion of the follower rests in a recess of the key shank, the other end portion extends to, but not beyond, the circumference of the key-receiving member. In these positions, the followers do not inhibit rotation of the key-receiving member about the cylinder axis 1 7.

For each of the followers 28 and 29, there is mounted in the intermediate portion 14 of the outer housing a respective lever 30, 31 which can pivot about a respective axis parallel to the cylinder axis 17. One end portion of each lever bears against the corresponding follower, or, when the key-receiving member is rotated, against the circumference of the key receiving member. The opposite end portion of each lever extends into a further housing component 32 which is mounted on the intermediate portion 14 of the outer housing, between the outer end portion 12 and the inner end portion 15. This housing component 32 contains signalling means for providing an electrical signal representing movement of the levers 30 and 31.

A single signalling means is operatively associated with the levers 30 and 31. This signalling means comprises a source 33 of radiation or of a field and a sensor 34 responsive to incident radiation from the source 33 or changes in the field associated with the source 33 to provide an electrical output signal. In the example illustrated, the source 33 is an infra-redemitting diode and irifra-red radiation can be transmitted from that diode along a rectilinear path which is parallel to the cylinder axis 17 to the sensor 34.

The levers 30 and 31 are provided with respective obstructing elements 35, 36 for interrupting the transmission of radiation from the diode 33 to the sensor 34. The obstructing element 35 is mounted in the housing component 32 for reciprocation along a path which is perpendicular to the cylinder axis 17 between an obstructing position shown in Figure 3 and a position in which it is clear of the transmission path between the diode 33 and the sensor 34. The obstructing element is urged by a spring 37 towards its obstructing position and can be moved from its obstructing position by the lever 30, when the follower 28 is forced out of a recess in the key shank.

The obstructing element 36 is adjacent to the element 35 and is arranged in substantially the same manner, but moves in the opposite direction from its obstructing position.

When the keyway of the lock is vacant and when the followers 28 and 29 both occupy recesses in the key shank, the obstructing elements 35 and 36 collectively block the transmission of infra-red radiation from the diode 33 to the sensor 34. Movement of either one of these followers out of its recess in the key shank causes the associated obstructing element to move from its obstructing position so that infra-red radiation from the diode 33 is incident on the sensor 34 and the latter provides an electrical pulse representing movement of that follower.

Signals provided by the sensor 34 are fed to a data processor (not shown) which may be incorporated in the lock 10 or in the associated device which is controlled by the lock.

A further pair of followers, 38 and 39, are provided in the key-receiving member 21 for engagement with the key shank in the recesses of the clock tracks. These followers are provided with respective levers 40, 41 and obstructing elements 42, 43 arranged in a similar manner to those of the followers 28 and 29. The obstructing elements 42 and 43 provide an operative association between the followers 38 and 39 and a single sensing means 44 comprising a further infra-red-emitting diode and sensor. Clock pulses from the sensor of the sensing means 44 also are fed to the microprocessor. These clock pulses are used to control the times at which the microprocessor accepts information from the sensor 34, thereby ensuring that the speed at which the key shank moves past the followers does not affect the information read from the key.

It will be understood that alternative forms of sensing means may be provided. For example, each sensing means may comprise a permanent magnet and a Hall effect device or other device which responds to changes in a magnetic field by providing an electrical output signal. In this case, the obstructing elements would be formed of magnetic material and arranged to change the magnetic field to which the Hall effect or other device is subjected.

Furthermore, each sensing means may be arranged to establish an electrostatic field which is disturbed by movement of the corresponding obstructing element. In a further alternative arrangement, each sensing means may comprise a pressure-sensitive device, the corresponding obstructing element being arranged for exerting pressure on the device.

It will be noted that the sensing means are spaced from the keyway of the lock. The sensing means 44 is spaced from the cylinder axis 17 in the same direction as the sensing means 33, 34 is spaced from that axis. In many applications of the lock, the risk of foreign matter entering the lock, via the keyway or otherwise, and contaminating the sensing means will be negligible. Ingress of foreign matter to the sensing means may be eliminated by sealing the sensing means in an enclosure. For example, the housing component 32 may be contained in a sealed enclosure, that enclosure having flexible parts which accommodate movement of the levers. Alternatively, the diode 33 and sensor 34 may be contained in a flexible envelope, the obstructing elements 35 and 36 being arranged to flex the envelope in such a manner as to interrupt the transmission of radiation from the diode 33 to the sensor 34. Such an envelope may be in the form of a tube with the source occupying one end portion of the tube and the sensor occupying the opposite end portion of the tube.

The clutch 55 incorporates a known, springloaded toggle mechanism which maintains the clutch in either the driving condition or the non-driving condition until a force is applied to the toggle mechanism. For applying force to the toggle mechanism, there are provided two solenoids 56 and 57, one of which can be energised by a pulse of electric current to set the clutch from the non-driving condition to the driving condition and the other of which solenoids serves as a disabling means and can be energised by a pulse of electric current to set the clutch from the driving condition to the nondriving condition. Electrical energy for energising the solenoids is derived from a battery 58 of dry cells disposed in a part of the body 1 which forms a housing on the inner face of the door.Energisation of the solenoids by the battery is controlled by the microprocessor which is contained in an electronic package 59 which also may be mounted in the housing adjacent to the battery.

The latch bolt 2 is provided with a further rack 60 meshed with a pinion 61 mounted in the body 1 for rotation relative thereto about a fixed axis and connected with the handle 4 by a spindle 62. The latch bolt 2 can slide longitudinally relative to the rack 60 so that the latch bolt can be moved by rotation of the toothed sector 51 to its retracted position without turning of the handle 4 and pinion 61.

Similarly, the latch bolt can slide to its retracted position relative to the rack 52 without movement of the toothed sector 51 occuring.

If the clutch 55 is arranged normally to be in its driving condition, energisation of either solenoid can be avoided during normal operation of the lock by the proper key. In the absence of the key, the key-receiving member 21 is restrained against rotation by the tumblers. When the proper key is inserted, the key-receiving member is freed for rotation and the key is used to transmit drive from the operator to the key-receiving member. A shutter (not shown) may be provided in the keyreceiving member normally to close the keyway and to be opened by the introduction of a key or of any other instrument into the keyway and to provide an electrical entry signal to the microprocessor when the shutter is moved.The microprocessor can then energise an appropriate one of the solenoids to set the clutch 55 in the non-driving condition, unless an appropriate set of data is read from the key within a predetermined interval, for example 0.5 seconds following movement of the shutter. Thus, if an incorrect key or other instrument is introduced into the keyway, the transmission means will fail to transmit drive from the key-receiving member to the latch bolt and the door will remain fastened.

With the arrangement described in the immediately preceding paragraph, the electrical energy drawn from the battery on each occasion when the correct key is used to operate the lock is very small. The entry signal can be used to energise the micro-processor and the reading means. The reading means can be deenergised by the micro-processor, once the correct data has been read from the key. Provided that the correct key is used, neither of the solenoids would be energised.

Alternatively, the clutch 55 may be arranged normally to be in a nondriving condition and settable in a driving condition only when an appropriate set of data is read from a key introduced into the keyway. In this case, energisation of an appropriate solenoid would be required on each occasion when the proper key is used, in order to set the clutch in the driving condition. The other solenoid would be energised when the key is withdrawn to set the clutch in the non-driving condition. A brief pulse of electrical energy is all that is required to change the condition of the clutch.

The tumblers may be omitted, so that the key-receiving member is freely rotatable, even in the absence of the proper key. In this case, the clutch would be in a non-driving condition, at least during insertion of a key or other instrument in the key-receiving member. Once the appropriate data had been read from the key, the microprocessor would cause the clutch to assume its driving condition. The non-driving condition of the clutch would be re-established either when the shutter moves upon withdrawal of the key or when the entry signal is again provided.

An arrangement in which the clutch is normally in a driving condition, in the absence of a key, is set in a non-driving condition by the insertion of a key or of any other instrument into the key-receiving member and is set in a driving condition once more, provided the correct data has been read from the key has the advantage that, if the key-reading means or microprocessor should fail, the clutch is likely to remain in the driving condition. Drive can then be transmitted from the key to the latch bolt, in order to gain access to the inside face of the door and, if necessary, to the housing which contains the battery, micro-processor and other electrical components. It will be appreciated that, in a case where the clutch is normally in a driving condition, in the absence of a key, locking of the key-receiving member by tumblers or other locking elements is generally required.

A push button 63 is provided for enabling an operator to apply a force directly to the clutch 55, from the inside of the door, to set the clutch in a non-driving condition. This prevents the door being opened, even by the holder of an appropropriate key.

The arrangement may be such that each successive movement of the push button changes the condition of the clutch. Thus, the push button could be used for re-establishing the driving condition of the clutch. Alternatively the push button may actuate a switch, the condition of which would be tested by the microprocessor. Whilst the switch is in a predetermined condition, the microprocessdr may prevent the transmission of drive from the key-receiving member to the latch bolt entirely or may prevent the use of some keys to move the latch bolt, limiting operation of the latch bolt to certain keys only.

It will be understood that, whiist use of a pair of solenoids is convenient and economi cal, because the cores of the solenoids can be formed of soft iron, a single electromagnet having a permanently magnetised armature could be used to set the clutch in a selected one of driving and non-driving conditions.

The clutch illustrated in Figure 1 comprises a flange 64 on an end portion of the sleeve remote from the sector 51 and a similar flange 65 on the shaft 54. A coupling element 66 is engageable with these flanges in respective openings defined thereby to couple the flanges together and establish the driving condition of the clutch. The coupling element is carried by a carrier 67 which can be moved by the toggle device (not shown) to withdraw the coupling element from one of the flanges and thereby establish the non-driving condition of the clutch.

When a key is introduced into the keyway of the key-receiving member 21, a signal is provided to the microprocessor by the shutter (if provided) and the clock tracks and data tracks then move past the followers at respective reading positions. The formations on the key which engage the tumblers avoid the reading positions. Successive bits of information are read from the data tracks by the sensing means 33, 34 at intervals determined by the clock tracks. During reading, the followers protrude momentarily from the circumference of the key-receiving member but the latter is not rotated. As the key shank moves into its fully-inserted position, it moves the tumblers 24 into respective releasing positions and the followers 28, 29, 38 and 39 come to rest in respective recesses in the key shank.

The key-receiving member is then free to rotate relative to the outer housing 11 and the user can drive the key-receiving member and the bolt 19 by means of the key.

It will be noted that, during insertion of the key, the cycle time of each of the obstructing elements 42 and 43 is twice the interval between successive signals provided by the sensing means 44.

Immediately a predetermined number of bits has been passed to the microprocessor from the sensor 34, the number represented by those bits collectively is compared with a number stored in a memory associated with the microprocessor. The microprocessor is thereby able to decide whether operation of the lock and associated device should be permitted and to provide or not provide a signal to the solenoids, accordingly. The microprocessor may perform additional functions. The number read from the key may be stored for subsequent retrieval. The time at which the key is used also may be stored.

It will be understood that, when there is introduced into the keyway of the key-receiving member 21 a key or other instrument which does not bear data acceptable to the microprocessor, operation of the latch bolt 2 by movement of the key-receiving member by means of the instrument is prevented since the transmission means 50 is unable to transmit drive. Thus, use of the fastening device by an unauthorised person who is able to pick the tumblers of the lock is prevented.

The outer housing 11, including the housing component 32, occupies a space which may be substantially the same as that occupied by a known pin-tumbler lock cylinder. Accordingly, the lock illustrated in Figures 1 to 5 the accompanying drawings may be substituted for a known cylinder lock and used for substantially the same purpose.

The lock illustrated in Figures 1 to 5 may be modified by the provision of a number of contact elements, one for each of the levers 30, 31, 40 and 41. Each contact element would be interposed between the associated lever and the keyway to protrude somewhat into the keyway, in the absence of the key, and with the lever bearing against the contact element. The preferred form of contact element is a ball. A ball interposed between the lever and the keyway can roll on the key during insertion of the key into and withdrawal of the key from the keyway. The recesses of the data tracks and clock tracks may be cylindrical or these tracks may comprise parallel sided apertures through the key.

It will be noted that the pivots of the levers 30, 31, 40 and 41 are so positioned that the levers amplify the movement derived from the recesses of the key shank, each obstructing element being moved through a distance which is greater than the depth of the recesses in the key shank. The depth of each recess in the key shank is preferably substantially smaller than is the thickness of the key shank and therefore substantially smaller than the minor dimension of the keyway. With the arrangement shown, the movement of each follower is no greater than one third the minor dimension of the keyway.

It will be understood that other cylinder locks, including known cylinder locks, could besubstituted for the lock 10 to operate the latch bolt of the device illustrated in the drawings. An example of an alternative, novel lock is one wherein there are provided a reader as hereinbefore described, a key-receiving member and locking elements of magnetic material which can be moved from respective locking positions to releasing positions by a magnetic field associated with a key introduced into the lock. A known arrangement of magnetic locking elements may be used. If magnetic locking elements are used, the pin tumblers 24 would normally be omitted.

In a case where there is used a known cylinder lock which does not provide an electrical output for controlling the clutch 55, the clutch would be omitted, there being provided a permanent driving connection between the sleeve 53 and the key-receiving member of the lack.

Known means may be provided for disabling the fastener either after use of the proper key or upon insertion into the keyway of an instrument from which the reading means is enabled to read acceptable data. Such disabling means may comprise a locking element controlled by a solenoid and movable between a locking position in which it obstructs movement of the key-receiving member or of parts driven thereby and a releasing position in which it does not obstruct operation of the device.

In Figure 9, there is illustrated a modified version of the device shown in the preceding figures. Certain parts of the modified device correspond to parts hereinbefore described and such corresponding parts are indicated in Figure 9 by like reference numbers with the prefix 1. The preceding description description is deemed to apply to the device of Figure 9, except for the differences hereinafter mentioned.

The device of Figure 9 includes a mortice latch 171 which includes a spring-loaded, reciprocating latch bolt 172. This mortice latch may be a known mortice latch or a mortice latch as illustrated in Figures 7 and 8. For moving the latch bolt between a projected position and a retracted position, there is provided a spindle 173. The spindle may be arranged to engage a cam (not shown) provided in the mortice latch or the spindle may drive the latch bolt through the intermediary of a rack and pinnion mechanism. There are carried on the spindle 173 two sprockets, 174 and 175, which rotate together with the spindle and which may be formed integrally one with the other.

For driving the sprocket 175, there is provided a handle 1 76 which is accessible to a user at the inside of a door to which the device is fitted. The handle is mounted for rotation relative to the door about a cylinder axis 1 17. The handle is coupled by a spindle 162 with a driving wheel 161. The driving wheel also is rotatable relative to the door and to a body of the device (not shown) about the cylinder axis 117 and is biased by a spring 1 77 to a datum position. The driving wheel has at its periphery a row of teeth 178 which is interrupted by a recess 1 79. In the datum position of the driving wheel, the recess 179 is presented to the pinnion 175 so that none of the teeth 178 is enmeshed with teeth of the pinnion.Upon rotation of the handle 1 76 in either direction about the axis 117, teeth 178 are moved into meshing engagement with teeth of the pinnion 175 and the latter is rotated to retract the latch bolt 172.

For transmitting drive between the key receiving member 121 and the pinnion 174, there is provided a clutch 155. The clutch comprises a sleeve 153 within which an end portion of the key receiving member is received. This end portion is formed with an axially extending slot 180. The sleeve bears a row of teeth 181 similar to the row of teeth 178 and interrupted by a recess 182 corresponding to the recess 179. When the key is absent from the key receiving member, the recess 182 is prevented towards the pinnion 174 and none of the teeth 181 is enmeshed with teeth of the pinnion 174.

For keying the sleeve 153 to the key-receiving member 121, there is provided a plunger 166 which is mounted in the sleeve for reciprocation relative thereto in a direction radially of the axis 117. The plunger is biased by a spring 183 towards a position in which a radially outer end portion of the plunger protrudes from the sleeve and a radially inner end of the plunger is disposed within the sleeve and clear of the key receiving member 121.

A shoe 184 is mounted in the body of the device for reciprocation towards and away from the axis 117 and the plunger 166. The shoe is carried on a lever 185 having a fulcrum 186 which is fixed with respect to the body of the device. A pair of electro-magnets 156 and 157 are disposed adjacent to the lever 185 at respective sides of the fulcrum.

Rocking of the lever is limited by engagement with one or other of the electro-magnets. An over-centre spring 187 is connected with the lever 185 for holding the lever releasably at either end of the range of permitted rocking movement. The lever can be moved to the opposite end of the range of movement by applying an energised pulse to an appropriate one of the electro-magnets 156 and 157.

When the lever 185 is set at one end of its range of rocking movement, the shoe 184 is withdrawn from the plunger 166. Movement of the lever to the opposite end of the range of rocking movement causes the shoe to depress the plunger into the sleeve 153 so that an inner end portion of the plunger moves into the slot 180 and keys the sleeve to the key receiving member 121. The pinnion 174 can then be rotated by means of a key present in the key receiving member. It will be noted that, during such rotation, the handle 176 is not turned. Similarly, when the key is absent and the handle 1 76 is turned, the sleeve 153 will not be turned.

The device further comprises a switch 188 which is connected with the microprocessor (not shown) and is arranged to be operated by a rocker 189 accessible at the inside of the door. By means of the rocker, the switch can be set in a condition in which it instructs the microprocessor to maintain the clutch 1 55 in a non-driving condition or alternatively to establish the driving condition only in response to insertion of one or more particular keys selected from a range of alternative keys which can otherwise operate the device.

There is associated with the rocker 189 a resetting element 190 having an end portion 191 remote from the rocker and engaged with the driving wheel 161. When the rocker 189 is moved to set the switch 188 in a condition which instructs the microprocessor to limit or prevent operation of the device by means of keys inserted in the key receiving member, the end portion 191 is engaged in a notch in the driving wheel. Subsequent rotation of the driving wheel by means of the handle 176 in either direction forces the end portion 191 out of the notch and re-sets the rocker 189 and the switch 188.

The key-receiving member 121 may be incorporated in the lock 10 hereinbefore described herein. Alternatively, there may be no tumblers or other locking elements associated with the key-receiving member. In the latter case, the key-receiving member would be provided with means for reading information from a key and the clutch 155 would normally be in a non-driving condition until appropriate data is read from a key.

Whilst the invention has been exemplified by a device which incorporates a latch bolt for fastening a door, it will be understood that the invention may be applied to the control of other devices, for example an electrical switch or a valve for controlling fluid flow. For example, the device illustrated in Figures 1 to 7 may incorporate an electrical switch having a driven member which is turned or otherwise moved by the driving member 16.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims (16)

1. A combination comprising a key bearing information, a movable key-receiving member, reading means for reading said information from the key when the key is applied to said member and providing an electrical signal representing said information, an associated device which can be operated by movement of the key-receiving member by means of the key and control means for controlling operation of the associated device by movement of the key-receiving member, wherein the control means is arranged to disable the combination if the reading means fails to read acceptable information upon application of a key or like instrument to the key-receiving member so that operation of the associated device by movement of the key-receiving member by means of an instrument which does not bear information acceptable to the control means is prevented.

2. A combination according to Claim 1 wherein the control means includes a normally de-energised electrically energisable element which, when energised, disables the combination.

3. A combination according to Claim 1 or Claim 2 further including a locking element movable by means of the key, when applied to the key-receiving member, between a locking position in which the element obstructs movement of the key-receiving member and a releasing position in which it does not so obstruct movement of the key-receiving member.

4. A combination according to any preceding Claim comprising keydetector means distinct from the reading means and connected with the control means for providing thereto an entry signal when a key is applied to the key-receiving member.

5. A lock comprising a body, a key-receiving member mounted for movement relative to the body, an output element movable relative to the body with the key-receiving member when a proper key is applied thereto, reading means for reading information from a key applied to the key-receiving member, disabling means and control means for controlling operation of the disabling means, wherein the control means and disabling means are arranged to disable the lock if the reading means fails to read acceptable information upon application of a key or like instrument to the keyreceiving members so that movement of the output element by means of an instrument which does not bear information acceptable to the control means is prevented.

6. A lock according to Claim 5 further comprising a locking element movable by means of the key, when applied to the key-receiving member, between a lacking position in which the element obstructs movement of the keyreceiving member relative to the body and a releasing position in which the element does not so obstruct movement of the key-receiving member.

7. A combination according to any one of Claims 1 to 4 wherein said information is represented on the key by formations.

8. A combination according to Claim 7 wherein the reading means includes a contact element engageable with said formations during application of the key to the key-receiving member.

9. A lock comprising first and second locking means, each being capable independently of the other of establishing a secure condition of the lock, wherein the first locking means is adapted for direct actuation by a key, when the key is applied to the lock, and, in the absence of the key, the first locking means automatically establishes the secure condition, the lock further comprising reading means for reading data from the key and providing an electrical signal representing said data, key-detector means for providing an entry signal upon application of the key to the lock and control means operatively associated with the second locking means for causing same to establish or maintain the secure condition after the entry signal has been provided, unless a predetermined set of data or one of a plurality of alternative predetermined sets of data has been read from the key within a predetermined period commencing when the entry signal is provided.

10. A method of preventing use by unauthorised persons of a device having a movable driven member wherein there is combined with the device a key-receiving member, reading means for reading information from a key, when applied to the key-receiving member and control means for controlling use of the device, the key-receiving member being arranged for movement by means of the proper key, when applied thereto, and for transmitting drive to said driven member, wherein, as a consequence of application to the key-receiving member of an instrument other than a proper key but which is capable of moving the key-receiving member, the combination of said device and key-receiving member is disabled so that operation of the device by movement of the key-receiving member by the instrument is prevented.

11. A method of operating a lock having locking elements movable between locking and releasing positions, wherein there is applied to the lock a data-bearing key, the data is read from the key and is passed to a processor, the data read from the key is matched by the processor with corresponding data, the locking elements are moved by the key to their releasing positions and drive is transmitted from the operator to the lock by means of the key.

12. A method of operating a lock wherein there is applied to the lock a information-bearing key, the information is read from the key and is passed to a processor, the information read from the key is matched by the processor with corresponding information, means for transmitting drive from the key to a device to be controlled by the lock is set in a driving condition and drive is then transmitted from the operator to said device.

13. A lock comprising a key-receiving member, a driving member, transmission means for transmitting drive between said members, the transmitting means being settable in a selected one of a driving condition and a nondriving condition, and an electrically energisable setting means for changing the condition of the transmission means, the transmission means being arranged to remain in the selected condition whilst the setting means is not energised.

14. A fastening device substantially as herein described with reference to the accompanying drawings.

15. A method of operating a lock substantially as herein described with reference to the accompanying drawings.

16. Any novel feature or novel combination of features disclosed herein or in the accompanying drawings.