GB2169342A - Lock - Google Patents

Abstract

A lock has tumblers (24) for operation by a key (25) and followers (28, 29; 38, 39) which engage the key and are moved by formations (26, 27) on the key during insertion of the key. Movement of the followers is sensed by electronic devices (34, 44) which provide signals to a microprocessor for identification of the key.

Description

SPECIFICATION Lock and key method of operating a lock and lock for use in the method According to a first aspect of the present invention, there is provided a lock and a key wherein a shank of the key has formations which represent data and the lock has reading means for reading said data when the key is applied to the lock.

The reading means preferably provides an electrical output signal representing said data.

This output signal may be applied to an electronic processor which processes the data, for example compares the data read from the key with stored data. The lock may incorporate or be in communication with a memory in which there is stored data identifying an acceptable key or in which there is stored several alternative sets of data identifying alternative acceptable keys.

The reading means preferably comprises a follower arranged to engage said formations during insertion of the key shank into the lock and to be moved by successive formations so that the resulting movement of the follower represents data read from the key. The preferred reading means further comprises signalling means operatively associated with the follower to provide an electrical signal representing the movement of the follower and the data read from the key.

The signalling means is preferably spaced from a key-receiving member of the lock, the follower being provided with mechanical transmission means for transmitting motion to the vicinity of the signalling means. With this arrangement, the signalling means can be separated from the key-receiving member and precautions can conveniently be taken against foreign matter from outside the lock reaching the signalling means. For example, the signalling means may be in an hermetically sealed enclosure. Furthermore, the transmission means may be arranged to amplify the motion so that a relatively large change in the geometry of components in the vicinity of the signalling means can be caused by movement of a relatively small formation past the follower.

According to a second aspect of the invention, there is provided a lock defining a keyway and comprising a follower engageable with a key when inserted into the keyway and signalling means operatively associated with the follower for providing an electrical signal in response to movements of the follower, which movements are substantially smaller than the smallest dimension of the keyway.

According to a third aspect of the invention, there is provided a lock comprising a keyreceiving member and a driving member for driving a controlled device, when such device is associated with the lock, the lock further comprising transmission means for transmitting drive between the key-receiving member and the driving member, the transmission means being settable in a selected one of driving and non-driving conditions by energising of an electromagnet or by energising of a selected one of a pair of electromagnets, the or both electromagnets being incorporated in the lock.

According to a fourth aspect of the invention, there is provided a method of operating a lock wherein there is inserted into a keyway of the lock a key shank which has formations representing data, during movement of the key shank into the keyway, said data is read serially from successive formations of the key by reading means of the lock and, after movement of the key shank into the keyway, the key is used to transmit movement to a movable member of the lock.

According to a fifth aspect of the invention, there is provided a key comprising at least two rows of mechanical formations, a first of said rows comprising at least three mechanical formations, the distance between adjacent mechanical formations being substantially equal and a second of said rows comprising formations with unequal spacing.

Preferably, said two rows are on opposite faces of the key.

An example of a lock and key which are used in a method according to the fourth aspect of the invention and which embody other aspects of the invention will now be described, with reference to the accompanying drawings, wherein: FIGURE 1 shows diagrammatically the lock and a bolt device which is to be controlled by the 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 diagrammatic representation of a cross-section of an alternative lock in a plane perpendicular to an axis of the lock, and FIGURE 7 is a diagrammatic representation of a perspective view of certain components of a further alternative lock and of a key intended for operating the lock.

FIGURE 8 shows a cross-section of a further alternative lock in a plane perpendicular to an axis of the lock; FIGURE 9 shows the same cross-section of the further alternative lock of Figure 8, in a different operative position; FIGURE 10 shows a cross-section of the further alternative lock in a vertical plane con taining an axis of the lock; and FIGURE 11 shows a cross-section of the further alternative lock in a plane parallel to the cross-section of Figures 8 and 9.

The lock 10 shown in Figures 1 to 5 of the drawings comprises an outer housing 11 comprising a generally cylindrical and relatively short outer end portion 12, defining an axis 13 of the lock, an intermediate porton 14 which is off-set 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 offset from the lock axis 13.

The driving member 16 is intended for operating an associated device. In the example illustrated, the associated device comprises a body 18 which may be fixed on or in a door, for example, and in which there is mounted for reciprocation a bolt 19 which can protrude from the body 18 to lock the door in a ciosed position. The device comprises a cam 20 disposed in an opening in the bolt and keyed to the driving member 16 for rotation therewith.

Typically, at least an end portion of the driving member remote from the housing 11 is of non-circular cross-section and engages in a complementary opening in the cam.

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 11, 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 key-receiving 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 key-receiving 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.

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 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 1 7 when the key shank is in the key slot. 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 recesses 27 occupy certain only of a number of sites along the data track which are at half the pitch of 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 17.

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 keyreceiving 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-red-emitting diode and infra-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 1 7 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 1 7 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 microprocessor to which data which is read from the key is fed is used to control operation of the lock 10 and of the associated device. For controlling such operation, there is provided in th example illustrated a solenoid 45 having a plunger 46 which can enter an opening 47 in the bolt 19 to restrain longitudi nal movement of the bolt. The arrangement may be such that, when the bolt is in a projected position in which it locks the associated door, the plunger 46 normally occupies the opening 47 and the bolt can be released only by a signal from the microprocessor to the solenoid 45. Such signal would be required before rotation of the cam 20 by the key receiving member 21 can retract the bolt.Alternatively, the arrangement may be such that the plunger 46 is normally held out of the opening 47 but can be projected into that opening upon receipt by the solenoid of a signal from the microprocessor. This signal may be provided only when there is inserted into the keyway something from which the data appropriate for operation of the lock is not read within a predetermined interval, for example 0.5 seconds. In this case, a shutter may be provided in the key-receiving member 21 normally to close the keyway, to be opened by introduction of a key into the keyway and to provide an electrical signal to the microprocessor when the shutter is moved.

It will be noted that, since the cam 20 provides a mechanical connection between the bolt 19 and the key-receiving member 21, rotation of the key-receiving member relative to the outer housing 11 is prevented when the plunger 46 occupies the opening 47 in the bolt. Alternatively, the plunger 46 may be arranged to engage the key-receiving member 21 directly to restrain rotation thereof.

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. 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 fqllowers 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 solenoid 45, 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 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. 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 the accompanying drawings may be substituted for a known cylinder lock and used for substantially the same purpose.

In a further alternative arrangement, the solenoid 45 may be used to control the tranmission of drive from the key-receiving member 21 to the bolt 19, for example in the manner proposed in EP 94592. Means for transmitting drive may be settable in a selected one of driving and nondriving conditions by means of a pair of electromagnets, an appropriate one of which is energised briefly to change the condition of the driving means, under the control of the microprocessor. A mechanical arrangement holds the driving means in the selected condition until one or other of the electromagnets is again energised. Alternatively, a single electromagnet may be provided for changing the condition of the driving means.

In either case, it is preferred that the driving means will remain in the condition into which it has been set, without energisation of the solenoid being continued.

In Figure 6, there is illustrated a modified lock, certain parts of which are similar to or identical with parts of the lock hereinbefore described with reference to Figures 1 to 5. In Figure 6, such corresponding parts are represented by like reference numerals with the prefix 1 and the preceding description is deemed to apply to the lock of Figure 6, except for the differences hereinafter mentioned.

The lock of Figure 6 has a single follower 128 for the data track of the key and a single follower 138 for the clock track of the key.

These followers are mounted in the key re ceiving member 121 for reciprocation relative thereto along respective paths which are mutually inclined to each other. In the example illustrated, these paths are inclined at approximately 90" to each other.

The signalling means 133, 134 associated with the follower 128 may be identical with the signalling means hereinbefore described and include an obstructing element 135 mounted for reciprocation along a path which is an extension of the path of the follower 128. The obstructing element is urged towards the follower by a spring 137 and may itself engage the follower directly. Alternatively, a slider may be interposed between the obstructing element and the associated follower. In the example illustrated in Figure 6, a single follower is associated with the reading means 133, 134. When the key is absent, the obstructing element 135 obstructs the transmission of light along the path between the source 133 and the sensor 134. During insertion of the key, the obstructing element is moved intermittently to permit radiation emitted by the source 133 to fall on the sensor 134.

Sensing means 144 is associated with the follower 138 in the same manner as the sensing means 133, 134 is associated with the follower 128.

The key intended for use with the lock of Figure 6 has along one face of its bit a row of recesses which constitute a data track and along the opposite face a row of recesses which constitute a clock track. It will be understood that additional followers may be provided for co-operation with further tracks on the key-bit. Such an additional follower may have an obstructing element which obstructs the transmission of radiation between the source 133 and the sensor 134, or further sensing means be provided for such further follower.

The lock of Figure 6 may comprise tumblers arranged in the same manner as the tumblers 24 shown in Figure 2.

In an alternative reading means illustrated in Figure 7, the levers 40 and 41 are substituted by a single element 240 which is mounted for rotation relative to the housing of the lock and is engaged by successive formations 226 on the key, during insertion of the key so that each such formation turns the element through a predetermined angle. Drive is transmitted from this rotary element to a wheel 235 having a circumferential row of formations which obstruct the transmission of radiation or change a field associated with the sensing means 233,234. The sensing means is thereby enabled to provide an electrical pulse representing each formation on the key. These formations may constitute a clock track.A further row of formations on the key drives a corresponding rotatable element.and wheel associated with further sensing means which provides a stream of pulses representing infor- mation read from a data track of the key.

A further alternative lock in accordance with the invention is shown in Figures 8 to 11, to which the proceeding description is deemed to apply with the exception of the differences hereinafter mentioned. Corresponding parts are represented by like reference numerals with the prefix 4.

Referring to Figures 8 and 9, there is provided a resilient arm 301, 302 for each of the followers 428, 429. The lower end of each arm is fixed with respect to the lock housing.

The arms may comprise respective parts of a single, substantially "U" shaped spring 303.

An intermediate part of each arm bears against a respective follower 428, 429, such that motion may be imparted thereto from the follower and the arms urge respective followers into the keyway when the key is absent.

An upper end of each arm is operatively associated with a respective signalling means 304, 305. The two signalling means lie adjacent to and on opposite sides of the tumblers 424.

Each signalling means comprises a source of radiaton 306, 307 and a sensor 308, 309 responsive to incident radiation from the source, the upper end of each arm being provided with a respective obstructing element 313,314 such that in a first position radiation may pass from the source to the sensor, but when the arm is moved into a second position, the radiation incident on the sensor is interrupted. The movement of the obstructing element is substantially greater than the corresponding movement of the follower.

A further pair of followers (not shown) may be provided, offset vertically in the keyway from the followers 428, 429, so as to read a different pair of rows of information. The further pair is offset also from the followers 428, 429, along the lock axis so as to impart motion through a pair of resilient arms similar to those hereinbefore described and operatively associated with a further pair of signalling means similar to those hereinbefore described.

The arrangement described above provides a compact configuration, in that the followers 428, 429, the arms 301, 302 and the signalling means 304, 305 are, in combination, no wider than the key-receiving member.

It is desirable that a means is provided sensitive to entry of the key or any other foreign member into the key-way in order to activate the electronic parts of the lock. The provision of such a means allows the electronics to be automatically switched off when the lock is not in use, thus providing a considerable saving in energy.

Referring to Figure 11, an auxiliary follower 310 may be provided such that it can impart motion to a resilient, electrically conducting arm 311. On depression of the auxiliary follower, the arm 311 is caused to make electrical contact with electrically conducting mem ber 312. Electrical circuitry (not shown) is provided to activate the electronic parts of the lock when said electrical contact is made. Additionally, an electrical sensor (not shown) may be provided to activate the electronic parts of the lock when one of the mechanical tumblers 424 is moved, thus ensuring that the electronic parts are activated, even upon attempted picking of the lock without depression of the auxiliary follower. The arm 311 may comprise a part of the spring 303.

Alternatively, a shutter (not shown) may be provided to close the entrance to the key-way in the absence of a key or other foreign member, the shutter being operatively associated with a sensor arranged to activate the electronic parts of the lock whenever the shutter is opened by insertion of a key or other foreign body into the lock.

It will be appreciated that the reading means hereinbefore described can be used in a lock which does not have tumblers but has alternative means for preventing operation of the lock or of an associated device until an appropriate set of information has been read from the key.

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 (43)

1. A combination comprising a lock and a key wherein a shank of the key has formations which represent data and the lock has reading means for reading said data when the key is applied to the lock.

2. A combination according to Claim 1 wherein the lock defines a keyway and the reading means is arranged for reading the data from said formations serially as the key shank is inserted into the keyway.

3. A combination according to Claim 1 or Claim 2 wherein the lock comprises a housing and a key-receiving member which is movable relative to the housing by the key, when the key is present in the lock.

4. A combination according to any preceding claim wherein the reading means comprises a follower arranged to engage said formations during insertion of the key shank into the lock and to be moved by successive formations and wherein the reading means further comprises signalling means operatively associated with the follower to provide an electrical signal representing said formations.

5. A combination according to Claim 4 wherein the follower includes a component which flexes during insertion of the key to cause the signalling means to provide said output signal.

6. A combination according to Claim 4, as appendant to Claim 3, wherein the signalling means is spaced from the key-receiving member and the follower is provided with mechanical transmission means for transmitting motion to the vicinity of the signalling means.

7. A combination according to Claim 6 wherein the signalling means is spaced from the key-receiving member in a first direction and the transmission means does not protrude substantially from the key-receiving member in any direction perpendicular to said first direction.

8. A combination according to Claim 6 wherein the transmission means is arranged to amplify the transmitted motion.

9. A combination according to any one of Claims 6 to 8 wherein the transmission means flexes as the follower is moved by the key.

10. A combination according to any one of Claims 4 to 9 wherein the signalling means comprises a source of radiation or of a field and a sensor for responding to a predetermined change in the radiation incident on the sensor or in the field to provide an electrical output signal and wherein the follower is provided with an obstructing element for obstructing transmission of said radiation between the source and the sensor or for disturbing the field and thereby causing said predetermined change.

11. A combination according to any one of Claims 4 to 10 wherein the signalling means is sealed from the position occupied by the key.

12. A combination according to any one of Claims 4 to 10 wherein the reading means comprises two followers between which the key shank passes during insertion of the key shank into the lock and wherein said signalling means is operatively asociated with both of said followers.

13. A combination according to Claim 12 wherein both transmitting means for transmitting motion between the followers and the respective signalling means are provided by a single flexible element.

14. A combination according to Claim 12 wherein the reading means comprises a further pair of followers and a further signalling means operatively associated with the further pair of followers and wherein both said signalling means are spaced from the key in the same general direction.

15. A combination according to Claim 4 wherein the lock further comprises a processor for comparing data read from the key by the reading means with stored data.

16. A combination according to Claim 6 wherein the transmission means is arranged for reciprocation with the follower relative to the key-receiving member.

17. A combination according to Claim 4 wherein the follower is arranged for reciproca tion along a rectilinear path and the signalling means comprises a pair of elements disposed at opposite sides of an extension of said path.

18. A combination according to Claim 3 or any one of Claims 4 to 17 as appendant to Claim 3 wherein the lock further comprises a plurality of tumblers, each tumbler being arranged to occupy a locking position when the key is absent and to be held by the key in a releasing position when the key is present in the lock, the locking position being one in which the tumbler holds the key receiving member against movement relative to the housing.

19. A combination according to Claim 18 wherein the tumblers are arranged to engage the key at respective tumbler positions spaced from an end of a keyway defined by the keyreceiving member, the reading means engage the key at at least one position spaced from the said end of the keyway by a distance which falls substantially within the range of distances by which the tumbler positions are spaced from said end of the key-way.

20. A combination according to Claim 19 as appendent to Claim 14 wherein said tumblers lie between said signalling means.

21. A lock defining a keyway and comprising a follower engageable with a key when the key is inserted into the keyway, the lock further comprising signalling means operatively associated with the follower for providing an electrical signal in response to movements of the follower, which movements are substantially smaller than the smallest dimension of the keyway.

22. A lock according to Claim 21 wherein the follower is arranged for reciprocation along a rectilinear path and the signalling means comprises elements disposed at respective opposite sides of an extension of said path.

23. A lock according to Claim 21 wherein the follower is provided with means for amplifying said movements.

24. A lock according to any one of Claims 21 to 23 wherein the signalling means is sealed from the follower.

25. A lock according to any one of Claims 21, 23 and 24 comprising a pair of followers at respective opposite sides of the keyway and associated with common signalling means.

26. A lock according to any one of Claims 21, 23 and 24 comprising two pairs of followers, the followers of each pair being disposed at opposite sides of the keyway, and the followers of each pair being associated with a respective signalling means.

27. A lock according to Claim 21 wherein the follower includes a component which flexes during insertion of the key to cause the signalling means to provide said electrical signal.

28. A lock according to Claim 21 further comprising a key-receiving member and transmission means by which the signalling means are operatively associated with the follower and the signalling means is spaced from the key-receiving member in a first direction.

29. A lock according to Claim 28 wherein the transmission means flexes as the follower is moved by the key.

30. A lock according to Claim 28 or Claim 29 wherein the transmission means does not protrude substantially from the key-receiving member in any direction perpendicular to said first direction.

31. A method of operating a lock wherein there is inserted into a keyway of the lock a key shank which has formations representing data, during movement of the key shank into the keyway, said data is read serially from successive formations of the key by reading means of the lock and, after movement of the key shank into the keyway, the key is used to transmit movement to a movable member of the lock.

32. A method according to Claim 31 wherein said data is represented by an electrical output signal provided by the reading means and the key also moves tumblers of the lock into respective releasing positions as insertion of the key shank into the keyway is completed.

33. A method according to Claim 32 wherein, as insertion of the key shank into the keyway is commenced, key-detector means of the lock provides a key-entry signal to a data processor of the lock and wherein the data read from the key is fed to the processor and is compared with a stored set of data or with stored sets of data.

34. A lock having a key-receiving member and transmission means for transmitting drive from the key-receiving member to an associated device, when such device is associated with the lock, said driving means being settable in a selected one of driving and non-driving conditions and the lock comprising an electromagnet or a pair of electromagnets which is or a selected one of which is energisable for setting the driving means in a selected condition.

35. A key comprising at least two rows of mechanical formations, a first of said rows comprising at least three mechanical formations, the distances between adjacent mechanical formations being substantially equal and a second of said rows comprising formations with unequal spacing.

36. A key according to Claim 35 wherein said two rows are on opposite faces of the key.

37. A lock having reading means substantially as herein described with reference to Figures 1 to 5 of the accompanying drawings.

38. A lock according to Claim 37 modified substantially as herein described with reference to Figure 6 of the accompanying drawings.

39. A lock according to Claim 37 modified substantially as herein described with reference to Figure 7 of the accompanying drawing.

40. A lock and key substantially as herein described with reference to and as shown in Figures 1 to 5 of the accompanying drawings.

41. A lock and key according to Claim 40, modified substantially as herein described with reference to Figure 6 or with reference to Figure 7 of the accompanying drawings.

42. A key substantially as herein described with reference to and as shown in the accompanying drawings.

43. Any novel feature or novel combination of features disclosed herein and/or shown in the accompanying drawings.