The present invention relates to a key for a lock, the combination of the key and a lock, and the lock per se.

Figures 1 and 2 show a conventional cylinder lock 101 comprising an outer casing 103 having a cylindrical bore 105 therethrough. A plug 107 is housed in the cylindrical bore 105. In order to open the lock, the plug 107 must rotate in the cylindrical bore 105.

One end of the plug 107 comprises a shaped aperture known as the key slot 109. A suitably shaped key 111 fits in the key slot 109. The other end of the plug 107 has a lever (not shown) which activates a mechanism (not shown) to retract a locking bolt (not shown) from a recess (not ^■ shown) . A series of bores 113a to 113e, typically five or six of them, are radially drilled into the plug 107. These bores 113a to 113e each contain pins called differ pins 115a to 115e, which are of various lengths, and which are rounded at one end to permit a key 111 to easily radially outwardly displace them when the key 111 is inserted into the key slot 109.

Above each differ pin 115a to 115e is a corresponding driver pin 117a to 117e (only one shown) , which is spring-loaded by means of springs 118. The outer casing 103 also has several radial bores 119a to 119e (only one shown) , which communicate with the bores 113a to 113e of the plug 107 and which house the spring-loaded driver pins 117a to 117e.

With a properly shaped key 111 inserted into the key slot

117e will move radially outwardly, and because the length of the pins is specially designed to match the shape of the key 111, the junction between each differ pin 115a to 115e and each driver pin 117a to 117e will exactly align with shear line A. This alignment allows the key 111 and therefore the plug 107 with it, to rotate, thereby retracting the locking bolt (not shown) from the recess and opening the lock.

When the correct key 111 is not in the key slot 109, the the pins 115a to 115e and 117a to 117e are pushed down into the plug 107 by the springs 118 and the driver pins 117a to 117e straddle the shear line A, thereby preventing the plug 107 from rotating, thereby keeping the lock" closed.

Despite being a commonly used lock and key arrangement, the arrangement described above includes a number of disadvantages. For example, the key may easily be duplicated, thereby presenting a potential security threat to the owner of the lock and key arrangement.

Moreover, the lock may easily be manipulated (that is, "picked") to allow unauthorised rotation of the plug in the outer casing even without the correct key.

Preferred embodiments of the present invention seek to overcome or at least alleviate the above disadvantages of the prior art.

In accordance with a first aspect of the present -Invention, ^■ the-re- is- -provided -a—1-ock- comprising: -

(i) a body portion; and

(ii) a lock portion mounted in the body portion and having a key slot for receiving a key, wherein the lock portion is adapted to rotate about a first axis relative to the body portion;

wherein at least one of the lock portion and the body portion comprises :-

(a) at least one magnetic first locking element being movable by means of a magnet between a respective locking condition in which rotation of the lock portion relative to the body portion is prevented, and a respective unlocked condition in which rotation of the lock portion relative to the body portion is permitted; and

(b) at least one second locking ^" element movable between: a respective first position in which said second locking element engages a respective recess in at least one of the lock portion ^' and the body portion and prevents rotation of the lock portion relative to the body portion, and a respective second position in which the second locking element does not engage said respective recess and allows rotation of the lock portion relative to the body portion, characterised in that at least one said first locking element in the locking condition thereof in use prevents movement of at least one said second locking element to the- second posi-t-i-on thereof.

This provides the advantage that the lock is secure, in that a key having a suitable magnet for moving the first locking element is required to open the lock.

At least one said second locking element may be mounted on said lock portion and when in said respective first position, engages a respective recess in the body portion .

This provides the advantage that the second locking element ensures that rotation of the lock portion is prevented in the event that the first locking element is in the locking position, i.e. when a suitable key is not disposed in the lock.

At least one said recess may be a bore arranged substantially perpendicular to said first axis.

This provides the advantage that the lock is compact.

When the or each said first locking element is in the unlocked condition thereof, at least one said second locking element may be adapted to be moved from a first condition to a second condition thereof as a result of rotation of said lock portion relative to the body portion .

This provides the advantage that the second locking element may be moved by means of rotating the lock portion, with further means of moving the second locking element not being required. Because of this, the lock is simple -and- compact.

At least one said second locking element may comprise a respective rounded end for engaging a respective said recess .

This provides the advantage that the second locking element may be easily displaced as the lock portion is rotated.

In accordance with a second aspect of the present invention, there is provided a combination of a lock as described above, and a key, said key comprising: -

(i) a shank portion for insertion into a key slot of a lock; and

(ii) a handle portion adapted to be grasped by a user, wherein when the shank p ^' ortion is inserted in a key slot of ^" a lock, the handle portion is disposed externally to the key slot of the lock,

wherein the handle portion of the ^' key comprises at least one magnet .

The handle portion of the key may comprise a shoulder portion being disposed adjacent said shank portion, and a gripping portion, wherein at least one said magnet is disposed on the shoulder portion.

In accordance with a third aspect of the present invention, there is provided a combination of a lock and a . k≤y_, .saάd -LocJc_ooinpxi-sing~:. ^■ =_

(i) a body portion; and

(ii) a lock portion mounted in the body portion and having a key slot for receiving a key, wherein the lock portion is adapted to rotate about a first axis relative to the body portion;

wherein at least one of the lock portion and the body portion comprises at least one magnetic first locking element being movable by means of a magnet between a respective locking condition in which rotation of the lock portion relative to the body portion is prevented, and a respective unlocked condition in which rotation of the lock portion relative to the body portion is permit-ted,

said key comprising :-

:(i) a shank portion for insertion Unto a key slot of a lock; and

^' (ii) a handle portion adapted to be grasped by a user, wherein when the shank portion is inserted in a key slot of a lock, the handle portion is disposed externally to the key slot of the lock,

wherein the handle portion of the key comprises at least one magnet.

This provides the advantage that a lock having a magnetic locking element, may be opened by- means of the key,

The handle portion may comprise a shoulder portion being disposed adjacent said shank portion, and a gripping portion, wherein at least one said magnet is disposed on the shoulder portion.

This provides the advantage that there is less build up of debris in the lock, since any particles which stick to the magnet of the key remain outside the lock when the key is disposed in the key slot. In reducing the build up of debris inside the lock, wear is reduced and reliability is improved.

This provides the further advantage that the likelihood of damage or corruption to data stored on a magnetic strip, for ex-ample that found on a credit card, is reduced. This is because the shape of a handle portion of a key is such that it is less likely to come into

^* close proximity with a credit card than the shank portion of the key. :

• A preferred embodiment of the present invention will now be described, ^' by way of example only and not ih any limitative sense, with reference to the accompanying drawings in which: -

Figure 1 shows a sectional plan view of a prior art combination of a lock with a key inserted therein;

Figure 2 shows a sectional view from one end of the prior art lock of Figure 1;

.Figure -.3 -shows a sectional- plan- view- of- a -Gombinat-i-en--o-f-- - a lock with a key inserted therein, in accordance with an embodiment of the present invention;

Figure 4 shows a side elevational view of a key in accordance with an embodiment of the present invention;

Figure 5 shows an elevational view from one end of the key of Figure 4; and

Figure 6 shows an elevational view from one end of the lock of Figure 3.

With reference to Figures 3 to 6, a lock 1 comprises a body portion 3 having a bore 5 of generally circular transverse cross section. Rotatably fitted in the bore 5 is a lock portion in the form of a generally cylindrical plug 7.

The plug 7 includes a key slot 9 formed therethrough, this communicating with a plurality of radial bores 11a to lie which are disposed along the length of the plug 7. In the locked position of the plug 7, the radial bores 11a to lie of the plug 7 are aligned with corresponding radial bores 13a to ^' 13e (only one shown) which are disposed along the length of the body 3, the bores 11a to lie being in direct communication with the bores 13a to 13e.

The plug 7 is normally secured against rotation in the body 3 by means of a system of pins and springs repeated along the length of the plug 7. For each set of aligned bores 11 and 13, there is a two pin arrangement in the form of a differ pin 15 and an associated driver pin 17, and an associated- coiled compression spr-ing 19 -in t-he body 3. One end of the spring 19 abuts the driver pin

17, whilst the other end of the spring 19 abuts the closed end of the radial bore 13 of the body 3.

As will be appreciated by persons skilled in the art, the biasing of the springs is such that each driver pin 17a for example and its associated differ pin 15a for example, is forced radially inwardly when there is no key in the key slot 9. In this way, the differ pins 15a to 15e are forced radially inwardly towards the centre of the plug 7. In this condition, the associated driver pin 17 straddles the interface between the outer surface of the plug 7 and the inner surface of the body 3, that is, the shear line A. With all of the driver pins 17 lying across the interface in this way, rotation of the plug 7 in the body 3 is prevented.

However, when a correctly cut key is inserted into the key slot 9, cuts and/or dimples in shank 25 of the key cause the pins 15, 17, being :of various lengths, all to move to positions such that the interface between the differ pins 15 and their associated driver pins 17 exactly coincides with the shear line A.

It can be seen that the key 21 has a handle portion 23 from which the shank 25 extends, wherein the cuts and/or dimples engage the hemispherical lower surface of the differ pins 15 as the key 21 is inserted so as to move the pins 15 and 17 and allow full insertion of the key.

As shown in Figure 4 in particular, the handle portion 23 of the key 21 includes a shoulder portion 27 and a gripping —portion—-2-8-,---w-her-eb-y— the shoulder porti-on -27, which abuts a front surface 30 of the plug 7 when the key 21 is fully properly inserted in the lock 1.

As can be seen from Figures 3 to 5 in particular, the key 21 is further provided with a small but powerful magnet 29, which is disposed on the shoulder portion 27 to one side of the shank 25. In this way, the magnet 29 does not form part of the shank, and is therefore external to that part of the key which in use, locates in the key slot 9 of the lock 1.

The plug 7 also includes a further longitudinal bore 39, which is formed longitudinally along the length of the plug 7 having its open end 41 on the front face 30 of the plug 7. The bore 39 houses a magnetic first locking element in the form of a magnetic pin 43, which is retained inside the bore 39 by a first small compression spring 45.

The plug 7 includes a further radial bore 31 drilled into the plug 7 such that the bore 31' is substantially perpendicular to the radial bores 11 for housing the pins 15, 17 in the plug 7, and the longitudinal bore 39. The bore 31 is located somewhere between the first 11a and second lib radial bores in the plug 7. The bore 31 houses ^' a second locking element in the form of a metal pin 33, which is retained inside the bore 31 by a second small compression spring 35. One end 37 of the metal pin 33 is rounded and when at rest, the pin 33 is urged outwardly so that it locates in a corresponding recess in the form of a bore 38 in the body 3 of the lock 1.

When a correctly cut key having no magnet 29 is disposed -in-the key s-±ot- 9,- the end-47 of the magnetic pin 4-3 is- urged to the right as shown in Figure 2 and abuts the metal pin 33 to prevent movement of the metal pin 33 from

its locked position where it is urged outwardly such that it locates in the radial bore 38 of the body 3 of the lock 1 to further prevent rotation of the plug 7 inside the body 3. In this way, rotation of the plug 7 is still prevented, even if the pins 15a to 15e and 17a to 17e are moved by a duplicate key into their correct position.

However, when the key 21 is inserted inside the key slot 9 of the plug the key is correctly shaped and so moves the pins 15 and 17 to a position such as to allow rotation of the plug 7. Furthermore, the magnet 29 attracts the magnetic pin 43 and as a result the magnetic pin 43 is pulled towards the magnet 29 and out of engagement with the metal pin 33. In this way, the metal pin 33 is no longer locked in position by the magnetic pin 43, and as the plug 7 is rotated, the rounded end 37 of the metal pin 33 is pushed out of engagement with the bore 38 in the body 3 and inside the plug 7 against the bias of the second small compression spring :35. As a result, the plug 7 can freely rotate as the key 21 is turned.

When the key 21 is then turned back to its original position, the metal pin 33 returns to its position whereby it locates in the bore 38 of the body 3. When the key 21 is then removed, the magnetic pin 43 returns to its locking position whereby it locks the metal pin 33 in place, to prevent rotation of the plug 7 in the body 3. Additionally, the pins 15, 17 also return to their locking position whereby the differ pins 15 straddle the shear line A.

The key, the lock, and the lock and key combination, one example of each being described above, act as a means for

improving security, in that a key which has the same cuts and/or dimples as a key such as that described above, i.e. a duplicate key, but not having a magnet, would not operate the lock. Such a key having a magnet is more difficult to duplicate than a key not having a magnet.

Moreover, in having the magnetic feature, the lock is resistant to "picking" and manipulation.

Moreover, the key and lock combination, one example of which is described above, is based upon a modification which can be easily made to a conventional lock and key combination without the necessity for significant structural changes.

It will be appreciated by persons skilled in the art that the above embodiment has been described by way of example only, and not in any limitative sense, and that various alterations and '. modifications are possible without departing from the scope of the invention as defined by the appended claims .