WO1988000635A1

WO1988000635A1 - Information carrier and reader and method of verifying key

Info

Publication number: WO1988000635A1
Application number: PCT/GB1986/000406
Authority: WO
Inventors: John O'connell; Roy Stephen Jefferies
Original assignee: Lowe & Fletcher Limited
Priority date: 1986-07-14
Filing date: 1986-07-14
Publication date: 1988-01-28
Also published as: EP0278950A1; DE278950T1

Abstract

A reader for a key (55) having rows of depressions (56, 57) along opposite faces of the key representing data which identifies the key is read by a device having contact elements (37, 38) which protrude into a key-slot (20) to engage the key adjacent to respective rows of depressions and which are caused to reciprocate as the depressions move past the contact elements. Photo-electric devices (43, 44, 47, 48) provide electrical output signals representing movement of the contact elements.

Description

Title: "Information carrier and reader and method of verifying key"

Description of Invention

From a first aspect, the present invention provides a reader defining a passage for receiving an information carrier and comprising a contact element movable between a first position in which the contact element is just withdrawn from the passage and a second position in which the contact element protrudes into the passage, signalling means for responding to movement of the contact element by providing an electrical output signal representing said information and transmitting means for transmitting motion from the contact element to the signalling means.

The preferred reader is characterised by signalling means which includes a source of radiation, a detector of said radiation arranged to receive radiation transmitted from the source along a path and interrupting means for interrupting transmission of radiation along that path to the detector, the interrupting means being movable by the contact element.

A reader in accordance with the invention may be used for verifying a key having a row of formations extending along a part of the key which can be introduced into the passage, the contact element contacting the formations in succession as the key is inserted into the reader. The key may serve merely to carry information which is read from the key by the reader and an electrical output signal may be provided upon verification of the key. Alternatively, the reader may be a lock having a key-receiving member which is driven by the key. After verification of the key, the lock may be used to transmit drive from a user, via the key, to an electrical switch, a bolt or other device which is to be controlled by the lock.

There may be associated with the or each contact element a single interrupting means and a single detector may be associated with that interrupting means to provide a signal when the contact element moves through a position which is between its first and second positions. In this case, the signalling means has only two states and these may correspond to the presence of or absence of a formation at a predetermined position on the key.

The preferred reader comprises a screen which is opaque to said radiation and which defines an orifice, said path extending through the orifice. The orifice is preferably small, as compared with the detector.

There may be associated with each source-detector pair two screens which are opaque to the radiation and defining respective orifices through which the path extends. In this case, the interrupting means is preferably disposed between the screens. According to a second aspect of the Invention, there is provided a combination comprising a reader according to the first aspect of the invention and an information carrier having a portion suitable for insertion into said passage, wherein said portion Includes a row of formations, each of which is engaged by the contact element when the said portion is inserted into the passage.

In a case where the reader is a lock including a key-receiving member defining said passage and a housing for the key-receiving member, the keyreceiving member being arranged for movement relative to the housing and locking means being provided for locking the key-receiving member against movement relative to the housing or a further component of the lock, the key is preferably adapted to transmit drive from a user to the key-receiving member for moving same relative to the housing.

The key may be adapted to actuate the locking means. For example, the locking means may comprise one or more tumblers engageable by the key. Additionally or alternatively, the locking means may comprise an obstructing element which is movable by an electrically energlsable device In at least one direction between an obstructing position In which the obstructing element obstructs movement of the key-receiving member relative to a further component of the lock and a releasing position in which such relative movement is permitted, energisation of the electrically energisable device being controlled In dependence upon verification of the key.

In a case where the information carrier of a combination in accordance with the second aspect of the invention has a single row of formations, each formation of that row preferably has dimensions such that reciprocation of the contact element through substantially the same distance accompanies movement of all of the formations past the contact element. In a case where have dimensions such that the reciprocation of the respective contact elements which accompanies movement of the rows past the corresponding contact elements is substantially the same.

Each formation of the carrier may be a depression in a face of the information carrier, generally a substantially flat face. All of the discreet depressions in the information carrier or all discreet depressions in the information carrier which are arranged in rows may have substantially the same depth.

The arrangement of the reader is preferably such that the movement of the or each contact element into the passage which occurs as each formation is moved past the contact element is limited by the reader, not by the information carrier.

The preferred form of contact element Is a rolling element. Each formation of the carrier may have a pair of substantially parallel boundary surfaces which are spaced apart In a direction along the row which includes that formation. Each formation in the carrier is preferably a substantially cylindrical depression.

Said portion of the preferred information carrier has at least one additional row of formations offset from and parallel to said one row. In this case, the reader of the combination includes a contact element, transmitting means and signalling means for each row of formations in the carrier. One of the rows may constitute a clocktrack and the or each other row a data track.

The transmitting means of the reader preferably includes a lever arranged to amplify the motion of the contact element and to apply the amplified motion to the signalling means. The lever may be arranged with its length transverse to the direction of movement of the contact element and substantially parallel to the direction of movement of the carrier into and out of the passage.

The lever preferably amplifies the movement of the contact element by a factor substantially in excess of two.

The reader preferably comprises a pivot for mounting the lever in the reader for pivoting relative thereto about a pivot axis between opposite ends of the lever, in which case the signalling means is preferably at one end of the lever and the contact element is preferably at the opposite end of the lever. This facilitates acceptance of moderate tolerances in the dimensions of the carrier. The lever can pivot inwardly of the reader to a limit position defined by the reader, rather than by the carrier. The arrangement also defined by the reader, rather than by the carrier. The arrangement also facilitates attainment of a fairly large factor of amplification, so that the required movement of the contact element can be small, for example less than one millimetre. In the preferred reader, the contact element projects into the passage a distance less than one millimetre, when the carrier is absent.

In a case where the reader of a combination according to the second aspect of the invention is a lock having locking means for locking a keyreceiving member against movement relative to a further component of the lock, the locking means may be comprised by the transmitting means.

The lock may comprise a follower mounted in the key-receiving member and associated with the contact element to reciprocate with that element, the follower being arranged to lie entirely inside the key-receiving member when the contact element occupies a depression defined by the carrier.

In the preferred lock, the lever is always spaced from the key-receiving member.

The preferred transmitting means comprises a follower so associated with the contact element as to reciprocate with the contact element between respective limit positions, in both of which the follower is disposed entirely in the key-receiving member, and a further element which reciprocates with the follower but which lies outside the key-receiving member in at least one of its positions. The contact element may be an integral part of the follower or a separately formed part which bears against the follower. The further element may be an integral part of the lever but is preferably a separately formed part which bears on the lever.

According to a further aspect of the invention, there is provided a method of verifying a key having at least one row of formations, wherein a part of said key which includes said row is inserted into a reader, a contact element of the reader engages each formation of the row in turn, the contact element undergoes repeated, substantially Identical movements, one for each formation, there is provided an electrical signal representing said movements and said signal is used In a comparison of data read from the key with predetermined data. The data is preferably represented by said formations in binary code, all formations of the key representing respective binary bits having the same value. During movement of each formation past the contact element, movement of the contact element may be arrested by the reader so that there is a moment when the contact element is clear of the key.

Preferably, a microprocessor is used to make the comparison and a keyentry signal Is provided to the micrprocessor to alert the processor whenever the key is introduced into the reader. In a case where the electrical signal representing movement of the contact element Is provided by electrically energisable signalling means, the key entry signal may also be used to energise a signalling means. When a predetermined number of bits of data has been read from the key, the position of the key may be checked by the microprocessor. The arrangement may be such that the microprocessor can check that some part of the key is present in the reader. Alternatively, the arrangement may be such that the microprocessor can check that the key is at a predetermined position within the reader, for example has been inserted as far as possible into the reader. The position of the key may be checked by comparing the position of the contact element with a predetermined position or by comparing the positions of a plurality of contact elements with a plurality of predetermined positions. The key may have a further row of formations constituting a clocktrack, a further contact element being provided in the reader for engaging the further row of formations and movement of the further contact element may be used to determine the times at which said one row of formations is interrogated. Said one row may be interrogated each time the further contact element reaches a depression of the clocktrack and also Interrogated each time the further contact element leaves a depression of the clocktrack.

In a case where the reader is a lock comprising a body, a key-receiving member mounted in the body for rotation relative thereto and locking means for locking the key-receiving member against rotation relative to the body in the absence of the key, the key, when said part of the key is inserted into the reader, may move the locking means to a releasing position in which the locking means no longer obstructs rotation of the key-receiving member. The key may subsequently be used to transmit torque to the key-receiving member.

In the preferred method, the key moves the locking means to Its releasing position at the time when the last of said predetermined number of bits is read from the key. The lock may further Include an obstructing element for obstructing rotation of the key-receiving member relative to the body and electrically energisable means for moving the obstructing element. In this case, the microprocessor preferably energises the electrically energisable means either upon verification of the key, or from production of the key-entry signal until the key is verified or upon elapse of a predetermined period from the keyentry signal, unless the key is verified within said period.

Examples of a lock and of a reader embodying the present invention will now be described, with reference to the accompanying drawings, wherein:-

FIGURE 1 shows an end elevation of a lock embodying the present invention,

FIGURE 2 shows a cross-section through the lock on the line II-II of Figure 1, FIGURE 3 shows a cross-section through the lock on the line III-III of

Figure 2,

FIGURE 4 shows a cross-section of the lock on the line IV-IV of Figure 2,

FIGURE 5 shows a key for operation of the lock: FIGURE 6 illustrates diagramatically a reader for verifying a key; and

FIGURE 7 Is a fragmentary view illustrating interaction between the key and contact elements of the reader shown in Figure 5.

The lock illustrated in Figures I to 4 comprises a housing 10 which Includes a cylindrical end portion 1 1 defining an axis 12 of the housing and a part-cylindrical end portion 13 which is co-axϊal with the end portion 1 1. For use, the lock would be mounted In an opening in a larger member, for example a door or a panel and the end portion 1 1 would be accessible from the outside of the door or panel. The end portion 1 1 is hereinafter called the outer end portion and the end portion 13 Is hereinafter called the inner end portion. Extending between the outer and Inner end portions of the housing, there is a cylindrical portion 14 of the housing defining a through bore, In which there is disposed a key-receiving barrel 15. The barrel is arranged for rotation relative to the housing about an axis 16 but is restrained against movement along that axis relative to the housing. The barrel has at an outer end a radially projecting flange 17 which seats is a recess defined by the outer end portion of the housing. An inner end portion of the barrel 15 carries a circlip which overlaps with the portion 14 of the housing to prevent movement of the barrel in a direction from the inner end portion towards the outer end portion. The axis 16 is offset from the axis 12 and is normally positioned below that axis. The barrel 15 carries a drive shaft 18 which projects beyond the inner end portion 13 of the housing to transmit drive to an electric switch 19 which is to be controlled by the lock. It will be understood that the lock may be used for controlling operation of other devices, for example a cam and bolt mechanism used for fastening a door. Association of locks with such controlled devices is well known and need not be furthered described. For turning the barrel 15, there is used a key shown in Figure 5. The key has a handle at one end of a rectilinear shank 55 and the shank has a cross-section transverse to its length such that the shank is a sliding fit in a substantially rectangular keyslot 20 defined by the barrel 15. When the shank is in the keyslot, the key is able to transmit torque from a user to the barrel and to the shaft 18 which is rotationally fixed with respect to the barrel.

Control means is provided for controlling rotation of the barrel 15 relative to the housing about the axis 16. The control means includes a number of pin-tumblers 21 arranged in a known manner. Each tumbler is urged by an associated spring into a locking position shown in Figure 2, in which a first portion 22 of the tumbler protrudes into the key slot 20 and a second portion 23 of the tumbler lies partly in the barrel 15 and partly in a tumbler-housing portion 24 of the housing 10 to restrain rotation of the barrel relative to the housing. The housing portion 24 also contains the tumbler springs and has the form of a rectangular, radial projection from the cylindrical portion of the housing, when the housing is viewed along the axis 12. The key is provided along at least one edge with a row of notches or other formations for engaging the tumblers 21 and displacing these to respective releasing positions, when the key shank has been fully inserted into the barrel. In the releasing positions of the tumblers, the portions 22 lie entirely in the barrel 15 and the portions 23 lie entirely in the housing.

The control means further comprises an obstructing element 25 mounted in a passage 26 which extends from the keyslot 20 to the circumference of the barrel 15. As shown in Figure 2, the element 25 can protrude from the passage 26 into a recess 27 defined by a guide 28 which is mounted in the housing 10 adjacent to the inner end portion 13. The position of the element 25 illustrated in Figure 2, in which the element lies partly in the recess 27 and partly in the passage 26 is a locking position. When the element is In the locking position, it restrains rotation of the barrel relative to the housing 10.

The obstructing element 25 is urged towards Its locking position by a spring 29 interposed between that element and a transmitting element 30 mounted in the passage 26 to protrude into the keyslot 20. The element 30 has the form of a cup and the spring 29 is disposed partly in that element.

For moving the obstructing element 25 from its locking position to a releasing position, in which the element is disposed entirely within the passage 26, there is provided an electrically energisable device, namely a solenoid 31 having an armature 32 which is guided for movement towards and away from the barrel 15. A slider 33 is interposed between the armature 32 and the obstructing element 25, the slider being guided by the guide 28 for reciprocation towards and away from the barrel. When the solenoid is energised, there is exerted on the armature 32 an electro-magnetic force which is sufficiently great to overcome the action of the spring 29 and move the obstructing element 25 Into its releasing position. The armature is then in contact with the guide 28. This guide is formed of mild steel and residual magnetism holds the armature In contact with the guide so that, even when energisation of the solenoid is terminated, the obstructing element 25 will still be held In its releasing position, against the action of the spring 29.

The control means further comprises a plurality of contact elements mounted in respective passages formed in the barrel 15 for movement between positions In which they project into the keyslot 20 and positions in which they are withdrawn from the keyslot. A first contact element 34 lies In a passage which extends from the keyslot to the circumference of the barrel 15 and which lies adjacent to the outer end of the barrel. The length of this contact element is equal to the length of its passage, so that when the contact element is just withdrawn from the keyslot, a radially outer end of the contact element lies at the circumference of the barrel. When the barrel is locked against rotation by the tumblers 21, a passage 35 in the cylindrical portion 14 of the housing is aligned with the passage In the barrel containing the element 34. A follower 36 is mounted in the passage 35 for reciprocation along that passage with reciprocation of the contact element. As shown in Figure 3, when the contact element 34 protrudes into the keyslot 20 and the follower 36 is engaged with the contact element, the follower occupies a locking position In which it lies partly in the housing and partly in the barrel, thereby restraining rotation of the barrel relative to the housing.

The control means comprises a further pair of contact elements 37,38, each having an associated follower and being arranged in respective passages, in substantially the same manner as are the contact element 34 and follower 36. The contact elements 37 and 38 lie at opposite sides of the keyslot, are spaced somewhat further from the outer end of the barrel than is the contact element 34 and lie somewhat nearer to the tumbler housing 24 than does the contact element 34.

There is mounted on the tumbler housing 24 a body 39 which extends down to and partly around the cylindrical portion 14 of the housing. A first lever 40 is mounted on the body for pivoting about an axis 41 which is parallel to the axis 16.

The lever 40 lies entirely outside the housing portions 14 and 24 but all parts of the lever lie nearer to the axis 16 than is the periphery of the outer end portion 1 1. The axis 41 lies between the ends of the lever and one end portion of the lever bears against the follower 36. An opposite end of the lever bears against a blade of a pair of electrical contacts 42 mounted on the body 39. In the absence of the key, the contact element 34 projects into the keyslot, the lever 40 is held by the resilience of the blade in contact with the follower 36 and the contacts 42 are in an open condition. When the key shank is introduced Into the keyslot 20, a leading end portion of the key engages the contact element 34 and pushes the contact element along its passage out of the keyslot so that the lever 40 is rocked to close the contacts 42 and provide an electrical signal indicating insertion of the key. Further signalling means for providing an electrical output signal representing movement of the contact elements 37 and 38 are mounted in the body 39. This signalling means includes a source 43 of radiation, namely a light-emitting diode and a detector 44 of radiation from the diode 43, these components being spaced apart by a gap 45 and so arranged that light emitted by the diode can fall on the detector. An optical axis 46 defined collectively by the LED 43 and detector 44 intersects the passage containing the contact element 37. A similar source-detector pair 47, 48 is mounted on the body 39 and defines an optical axis 49 which intersects the passage containing the contact element 38. A further lever 50 mounted on the body 39 for pivoting about the axis

41 , this lever lying beside the lever 40. The axis 41 lies between the ends of the lever 50 and a first end portion of this lever bears against the follower 51 associated with the contact element 37. A spring 52 acting between the body 39 and the lever 50 urges the lever about its axis 41 in a direction to maintain the lever in contact with the follower 51 and the contact element 37 projecting into the keyslot 20. At the end remote from the follower 51 , the lever has an interrupting element 53 which normally lies outside the gap 45, as shown in figure 4, but which can enter the gap when the lever rocks about its axis to Interrupt the transmission of radiation from the LED 43 to the detector 44. Interruption of the light path occurs during movement of the contact element 42 from the keyslot 20 and whilst the contact element still projects a substantial distance into the keyslot. Thus, an electrical signal representing movement of the contact element is produced by the detector 44, irrespective of the exact distance through which the contact element is moved.

There is associated with the contact element 38 a lever 54 which is arranged In a manner corresponding to that In which the lever 50 is arranged, the lever 54 having an interrupting element to Interrupt the lighttransmission path between the detector 48 and LED 47. It will be noted that the signalling means associated with the contact element 37 and the signalling means associated with the contact element 38 lie at opposite sides of the tumbler housing 24 but He in the same quadrant, with respect to the axis 16 of the barrel. The levers 50 and 54 always lie nearer to the axis 12 than is the periphery of the outer end portion 1 1 of the housing and movement of the contact elements out of the keyslot causes pivoting of the levers generally towards the axis 12. The key shank 55 has along each of its major faces a respective row of depressions 56 and 57. The row of depressions 56 constitutes a clocktrack of the key and the depressions in this row may have a uniform pitch. The depressions 57 constitute a data track of the key. Respective ones of the depressions 57 occupy some only of a number of sites along the key, each of these sites being centered at a position corresponding to one of a leading edge and a trailing edge of each of the depressions 56. The depressions 56 and 57 all have the same length and same depth. Accordingly, distinct depressions 57 cannot occupy immediately adjacent sites. Two immediately adjacent sites of the data track may be occupied by respective end portions of a single, somewhat elongated depression. The depressions 56 and 57 are so positioned that they move past the contact elements 37 and 38 respectively, during insertion of the key shank into the keyslot. The dimensions of the contact elements and of the depressions 56 and 57 may be such that, when a depression is completely aligned with the corresponding contact element, there is a small clearance between the contact element and all surfaces of the key, further movement of the contact element into the depression being prevented by co-operation between the contact element and the barrel 15. It will be noted that movement of a row of depressions past a contact element results in successive reciprocations of the contact elements which are identical one with another. The control means responds to the presence of or absence of a depression at a particular sight and is not capable of responding differently to different depressions, even if these depressions have somewhat different dimensions.

The control means further comprises a microprocessor represented in figure 1 at 58. The microprocessor may be spaced from the housing 10 and connected electrically with other components of the control means by electrical leads. Alternatively, the microprocessor may be mounted in or on the housing 10. A battery 59 of electrical cells is associated with the microprocessor, to supply power to the electrical components of the lock.

When the key is absent, the microprocessor interrogates the switch contacts 42 intermittently. ^'hilst these contacts remain open, other components of the control means are not energised. Upon insertion of a leading end portion of the key into the keyslot 20, the contacts 42 are closed by rocking of the lever 40. The microprocessor accepts this as an instruction to energise the source-detector pairs 43,44 and 47,48. The leading end portion of the key expels the contact element 34 from the keyslot 20 so that the follower 36 is moved completely out of the barrel 15 and no longer restrains rotation of the barrel. It will be noted that the contacts 42 are closed before the follower 36 leaves the barrel. Accordingly, the microprocessor is alerted whenever the barrel is released by the follower 36 for rotation. The leading end portion of the key also expels the contact elements 37 and 38 from the keyslot, rocking the associated levers to interrupt the associated light paths. When the leading edge of the first depression 56 of the clocktrack of the key moves past the tip of the contact element 37, that contact element enters the depression and moves sufficiently far into the keyslot the permit the associated light path to be restored. This causes the detector 43 to apply to the microprocessor a signal which is accepted as an Instruction to interrogate the detector 48. The condition of that detector will depend upon whether the associated contact element 38 projects into the keyslot or not. The contact element 38 can project into the keyslot whenever a depression 57 of the key is aligned with the contact element. As the trailing edge of the first depression 56 moves past the contact element 37, the associated light path is interrupted once more and a further signal is applied to the microprocessor. The microprocessor then interrogates the detector 48 once more. In a similar way, this detector is interrogated by the microprocessor twice when each successive depression of the clocktrack moves past the contact element 37. During manufacture, the microprocessor is adapted to respond to a predetermined number of signals from the detector 44. When this number of signals has been received by the microprocessor, the microprocessor Interrogates both of the detectors 44 and 48 and compares the actual conditions of these detectors with predetermined conditions as defined during manufacture. If the actual conditions of these detectors are the expected conditions, then the microprocessor compares with data stored in a memory of the microprocessor the data which has been read from the data track of the key. If the data read from the key is found to be acceptable, the microprocessor applies a brief pulse of electrical energy from the battery 59 to the solenoid 31. This causes the solenoid to set the obstructing element 25 in Its releasing position. If the key is then in, or is moved Into a position such that the key holds all of the tumblers 21 in respective releasing positions, the barrel 15 is freed by all of the locking means for rotation and the user can turn the barrel and the drive shaft 18 by appying torque, via the key. It will be noted that levers 40, 50 and 54 are always spaced from the barrel 15 and therefore do not interfere with rotation of the barrel. During rotation of the barrel, the followers 36 and 51 bear on the circumferential surface of the barrel 15. The slider 33 also bears against the circumferential surface of the barrel 15 and the obstructing element 25 is urged by Its spring against an internal surface of the cylindrical portion 14 of the housing.

The key shank 55 is provided, adjacent to its tip, with a projection 60 which, during Insertion of the key, moves past the transmitting element 30. Whilst the obstructing element 25 is held entirely in the passage 26 of the barrel, either by the cylindrical portion 14 or by the slider 33, the transmitting element 30 prevents movement of the projection 60 past the passage 26 and thereby prevents withdrawal of the key from the barrel. When the key is withdrawn, the projection 60 forces the transmitting element 30 out of the keyslot 20 into the passage 26. During this movement, the transmitting element is engaged with the obstructing element 25 so that the obstructing element is forced partly from the barrel into the recess 27 in the guide 28. The projection 60 of the key Is then able to move past the transmitting element 30 and the spring 29 can then return the transmitting element to the position shown in figure 2, spacing the transmitting element from the obstructing element. The spring 29 maintains the obstructing element in the locking position shown in figure 2. It will be understood that, when the obstructing element is driven by the key into the recess 27, the armature 32 is moved away from the guide 28 to the position shown in figure

2 and will remain in that position, until the solenoid is energised once more.

Accordingly, withdrawal of the key resets the electrically energisable part of the locking means to the normal condition, which is illustrated in figure 2.

Upon withdrawal of the key, the springs associated with the tumblers 21 move these into respective locking positions and the springs associated with the levers 40, 50 and 54 move the associated contact elements into the keyslot.

The follower 51 engages the lever 50 at a position which is nearer to the pivot axis 41 of the lever than is the interrupting element 53. Accordingly, the lever amplifies the motion of the follower and applies the amplified motion to the interrupting element. A small movement of the contact element is sufficient to interrupt the light path reliably. Thus, the contact element can be arranged to project only a small distance, preferably less than one millimetre, into the keyslot 20 so that the distance through which the contact element and the follower reciprocates also is less than one millimetre. The lever Is preferably arranged to amplify the motion of the contact element by a factor which is substantially greater than two.

In figure 6, there is illustrated a reader suitable for verifying a key, for example the key shown in Figure 5, or the somewhat different key 61 , a part of which is shown in figure 6. The key 61 does not have notches for operating tumblers and does not have a projection corresponding to the projection 60. The key does, however, have rows of depressions at opposite faces of the key, one row being a clocktrack and the other row being a data track. The depressions of these rows may be identical with the depressions 56 and 57 hereinbefore described but are preferably cylindrical.

The reader includes a key-receiving member 62 which corresponds to the barrel 15 but which would normally be non-rotatably mounted in a larger member, for example a panel or a machine housing. The member 62 defines a keyslot 64 corresponding to the slot 20 and passages extending from the keyslot to the periphery of the member, these passages corresponding to the passages containing the contact elements 37 and 38 hereinbefore described. In one of these passages, there is mounted a contact element 63 which is adapted to roll on a key and, in the example illustrated, is a ball. As shown in figure 7, the member 62 provides in the passage and adjacent to the keyslot an annular seat for the ball 63, this seat limiting movement of the ball into the keyslot. At a position remote from the keyslot, the ball 63 is engaged by an end portion of a lever 65 which is mounted in the member 62 for pivoting about an axis 66 which is perpendicular to a longitudinal axis defined by the member 62 and extending along the keyslot. The lever 65 lies partly in a channel formed in the member 62 and extending along that member, the channel being open to the space around the circumference of the member 62. At the side of the keyslot 64 opposite to the contact element 63, there is provided a further contact element 67 which is mounted In the keyreceiving member in a corresponding manner and is associated with a corresponding lever 68.

There is associated with the lever 65 signalling means comprising an LED 63 and a detector 70 for radiation emitted by the LED. Between the LED and the detector, there is disposed a pair of screens 71, 72 which are opaque to the radiation emitted by the LED and each of which defines a small orifice, through which the radiation can pass from the LED to the detector. The orifices collectively define an optical axis which is perpendicular to the length of the lever 65 and perpendicular to the direction of movement of the key 61 into and out of the member 62. An end portion of the lever 65 remote from the contact element 63 includes an obstructing element 73 which lies generally between the screens 71 and 72 and which can obstruct the light path extending through the orifices of these screens, when the instructing elements 23 is displaced from the keyslot 64. The obstructing element is urged by a spring 74 acting on the lever 65 to a position in which it is spaced from the light path passing through the orifices defined by the screens. Corresponding signalling means is associated with the lever 68, although omitted from figure 6, for the sake of clarity of illustration. The reader further comprises key-detector means for providing an electrical signal indicating presence of the key 61 in the keyslot 64. The key detector means comprises a contact element 75 arranged in a manner similar to that in which the contact element 63 is arranged and bearing against one end of a lever 76 also mounted for pivoting about the axis 66 and disposed partly in a groove defined by the member 62. The lever is urged against the contact element 75 by a spring 77. An end portion of the lever 76 remote from the contact element 75 Is adjacent to a pair of normally open electrical contacts 78. When the contact element 75 is expelled from the keyslot, the lever 76 is pivoted to close the contacts 78 and these contacts provide an electrical signal to an associated microprocessor corresponding to the processor 58. This alerts the microprocessor, which energises the LED 69 and detector 70.

As the key 61 is moved along the keyslot 64, the data track on the key is interrogated at intervals between the clocktrack on the key, as hereinbefore described with reference to the key of figure 5. As insertion of the key is completed, a tip of the key engages a finger 79 and displaces that finger from the keyslot to close a pair of electrical contacts 80. The microprocessor is adapted to check the position of the key 61 after a predetermined number of depressions of the clocktrack have moved past the corresponding contact element. In order to check the position of the key, the microprocessor interrogates the detectors of the signalling means to check the positions of the corresponding contact elements. If the conditions of both detectors are the expected conditions, the microprocessor then interrogates the switch contacts 78 and 80. If these contacts are in respective expected conditions, the data which has been read from the. key is compared with data stored in a memory of a microprocessor and the microprocessor then provides an appropriate output signal. The output signal may be used to control operaiion of a machine or operation of a device, for example a lock which can be driven by means of a permanent handle or which can be driven electrically.

The lock illustrated in figures 1 to 4 may be modified by the provision of contact elements similar to the contact elements 63 and 67. Furthermore, the levers and signalling means of the lock may be arranged as illustrated in figure 6. Either the lock of figures 1 to 4 or the reader of figures 6 and 7 may be modified by arranging the optical axis to be parallel to the direction of movement of the key. The lock of figure 2 may be modified by positioning one of the tumblers

21 between the passage 26 and the end portion 13 of the housing, so that this tumbler is positioned by the projections 60 of the key. It will be noted that, in the lock of figures 1 to 4, the solenoid 31 defines an axis which intersects the axis 16 of the key-receiving member so that the armature 32 and slider 33 reciprocate towards and away from that axis. The solenoid and the tumblers 21 all lie at the same side of the axis 16 and the signalling means lie at opposite sides of the row of tumblers, but In the same quadrant with respect to the axis 16. This results in an especially compact arrangement with all parts contained in a notional cylinder defined collectively by the end portions 1 1 and 13 of the housing. For each of the contact elements 37 and 38, there is provided only a single source of radiation and a single detector. Thus, the control means of the lock is able to distinguish between the presence of a depression at a particular position on the key and the absence of such depression but is not adapted to distinguish between depressions of slightly different size.

Each of the depressions 56 defined by the key shown In figure 5 may have a conical form or a trunkated conical form. Alternatively, as shown each depression may be somewhat elongated in the direction of the length of the row, having a relatively narrow flat surface at the bottom of the depression and boundary surfaces extending from that bottom to the major face of the key, which boundary surfaces are inclined to the major face of the key so that, at opposite ends of each depression, these surfaces form ramps down which and up which the contact element can slide. The contact element is preferably formed with correspondingly inclined surfaces which can engage in face-to-face contact with the inclined boundary surfaces of a depression 56. Alternatively, if the lock of figures 1 to 4 is provided with contact elements which are rolling elements similar to those herein described with reference to figures 6 and 7, the depressions of the key shown in figure 5 may be cylindrical depressions or other depressions having boundary surfaces which are substantially perpendicular to the major face of the key.

The features disclosed in the foregoing description, 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 any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

CLAIMS:-

1. A reader defining a passage for receiving an information carrier and comprising a contact element movable between a first position in which the contact element is iust withdrawn from the passage and a second position in which the contact element protrudes into the passage, signalling means for responding to movement of the contact element by providing an electrical output signal representing said information and transmitting means for transmitting motion from the contact, element to the signalling means, characterised in that the signalling means includes a source of radiation, a detector of said radiation arranged to receive radiation transmitted from the source along the path and interrupting means for interrupting transmission of radiation along said path to the detector, the interrupting means being movable by the contact element.

2. A reader according to Claim 1 wherein there is a single detector associated with the or each interrupting means to provide a signal when the corresponding contact element moves through a position which is between its first and second positions.

3. A reader according to Claim 1 or Claim 2 further comprising a screen which is opaque to said radiation and which defines an orifice through which said path extends.

4. A reader according to Claim 1 or Claim 2 further comprising two screens which are opaque to said radiation and defining respective orifices through which said path extends, the interrupting means being disposed between the screens.

5. The combination comprising a reader according to any preceding Claim and an information carrier having a portion suitable for insertion into said passage, wherein said portion has a row of formations, each of which formations is engaged by the contact element when said portion is inserted into the passage.

6. A combination according to Claim 5 wherein each formation of the row has dimensions such that reciprocation of the contact element through substantially the same distance accompanies movement of all formations past the contact element.

7. A combination according to Claim 6 wherein each said formation is a depression in a face of the information carrier and all of said formations have substantially the same depth.

8. A combination according to Claim 6 so arranged that movement of the contact element info the passage as each formations is past the contact element is limited by the reader, not by the information carrier.

9. A combination according to any one of Claims 5 to 8 wherein the contact element Is a rolling element.

10. A combination according to any one of Claims 5 to 9 wherein each formation has a pair of substantially parallel boundary surfaces spaced apart in a direction along the row.

1 1. A combination according to Claim 10 wherein each formation is a substantially cylindrical depression.

12. A combination according to any one of Claims 5 to 1 1 wherein said portion of the information carrier has at least one additional row of formations offset from and parallel to said row, wherein the reader includes a contact element, transmission means and signalling means for each row and wherein one of said rows constitutes a clocktrack and the other for each other row constitutes a data track.

13. A reader according to any one of Claims 1 to 4 or a combination according to any one of Claims 5 to 12 wherein transmitting means comprises a lever arranged with its length transverse to the direction of movement of the contact element and substantially parallel to the direction of movement of the carrier in and out of the passage.

14. A reader or a combination according to Claim 13 wherein said lever is arranged to amplify by a factor exceeding two the movement of the contact element and apply the amplified movement to the signalling means.

15. A reader or a combination according to Claim 14 wherein the contact element projects into the passage a distance which is less than one millimetre, when the key Is absent from the passage.

16. A combination according to any one of Claims 5 to 12 wherein the information carrier is a key, the reader is a lock, the reader includes a keyreceiving member defining said passage, the reader includes a housing for said key-receiving member, the key-receiving member is arranged for movement relative to the housing, the key Is adapted to transmit drive from the user to the key-receiving member for moving same relative to the housing and wherein locking means is provided for locking the key-receiving member against movement relative to a further component of the lock.

17. A combination according to Claim 16 wherein the key is adapted to displace the locking means to a releasing position.

18. A combination according to Claim 17 wherein the locking means is comprised by the transmitting means.

19. A combination according to any one of Claims 16 to 18 wherein the transmitting means includes a lever, there is provided a pivot for mounting the lever in the housing for pivoting relative to the housing and wherein the lever is outside the key-receiving member in all positions occupied by the lever during operation.

20. A method of verifying a key having at least one row of formations, wherein a part of said key which Includes said row is inserted into a reader, a contact element of the reader engages each formation of the row in turn, the contact element undergoes repeated, substantially identical movements, one for each formation, there is provided an electrical signal representing said movements and said signal is used in a comparison of date read from the key with predetermined data.

21. A method according to Claim 20 wherein said comparison Is made by a microprocessor and the microprocessor also checks that if there is fulfilled one of two conditions, namely a predetermined number of clock pulses originating in movement of the contact element by the key has been received by the microprocessor and the key occupies a predetermined position, then both of those conditions are fulfilled.

22. A method according to Claim 21 wherein attainment of a fully inserted position by the key is signalled to the microprocessor and wherein checking of the position of the key includes checking the presence of a signal indicating full insertion of the key.

23. A method according to any one of Claims 20 to 22 wherein the reader has signalling means for providing an electrical signal representing movement of the contact element, motion of the contact element, when engaged with the key, is amplified and the amplified motion is applied to the signalling means.

24. A method according to Claim 23 wherein the signalling means includes a photo-electric device and wherein the transmission of radiation to said photo-electric device is interrupted by a blocking element moved by said contact element.

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