GB2576488A

GB2576488A - A locking device

Info

Publication number: GB2576488A
Application number: GB1810568.4A
Authority: GB
Inventors: Green Glyn
Original assignee: Henry Squire and Sons Ltd
Current assignee: Henry Squire and Sons Ltd
Priority date: 2018-06-27
Filing date: 2018-06-27
Publication date: 2020-02-26
Also published as: GB201810568D0

Abstract

A locking device 10 e.g. a sliding bolt or a rotating cylinder lock, having first and second lock portions which move relative to one another with a shear line between them. An electromagnet 20 having a ferromagnetic core 22 is located in one of the lock portions and a pair of recesses each with a shuttle 54 56 comprising a magnet is located in the other lock portion. A processor 30 controls the lock and switches it from a locked condition where the shuttles are attracted to the ferromagnetic core and the shuttles straddle the shear line preventing the moving relative to one another and an unlocked condition where the electromagnet is activated and repels the shuttles moving them entirely within the recesses. The first portion may be the sliding bolt and the second portion the lock body in which the bolt slides. In a cylinder lock the first portion is a plug and the second portion is the barrel in which it may rotate. The blocking system provides an extra locking system to prevent locking bumping.

Description

A Locking Device

The present invention relates to a locking device, and relates particularly, but not exclusively, to an electronically controlled sliding bolt lock.

The use of electronic locking devices is widespread. However, such locking devices are often complex making them expensive and many of the benefits of the convenience of an electronic lock are not accessible to lower cost simple locking devices. Electronic locking devices have various advantages including, but not limited to, the changing of the code in both a lock and a key which can be used to regularly update the keys at minimal expense. For example, if a key is lost it is easy to update all the remaining keys and the lock with a new code without the need to replace any components.

Electronic locking devices commonly use solenoids to control the locking components. However, the use of solenoids in such devices can leave them vulnerable to the so-called technique of lock bumping. In this technique a knocking force is applied to the lock which causes the plunger in the solenoid to move which can allow the lock to be overcome.

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

According to the present invention there is provided a locking device comprising:at least one first lock portion;

at least one second lock portion wherein said first and second lock portions are movable relative to one another thereby forming at least one shear line at adjoining faces thereof;

at least one electromagnet having a ferromagnetic core and located in one of said first and second lock portions;

a plurality of recesses extending into the other of said first and second lock portions from at least one said shear line;

a plurality of shuttles respectively associated with said recesses and each comprising at least one permanent magnet;

at least one processor for receiving and processing a signal from a key associated with said locking device, the processor causing a current to pass through said electromagnet, wherein in response to a correctly coded said signal to said processor the locking device switches from a locked condition, in which said shuttles are attracted to said ferromagnetic core and straddle said shear line, to an unlocked condition, in which power is sent to said electromagnet thereby generating a magnetic field repelling said shuttles in different directions into said recesses and no longer straddling said shear line, thereby allowing movement of said first and second lock portions relative to each other.

By providing a lock with a ferromagnetic cored electromagnet which causes the movement in different directions of shuttles which include permanent magnets provides the advantage that a simple lock, such as a sliding bolt, can utilise the advanced security of an electronically coded lock into a mechanically simple and robust locking mechanism. Furthermore, because the shuttles move in different directions, and this is preferably in opposite directions, it is impossible to bump the lock. Any movement which can dislodge one of the shuttles sufficiently to make it move into the recess, will not move the other shuttle into its recess since this requires movement in the opposite direction.

In a preferred embodiment the first body portion is in use fixed relative to an apparatus being locked and said second body portion is moveable relative to said apparatus.

In another preferred embodiment the first body portion comprises said at least one electromagnet and said second body portion comprises said recesses.

By having the first body portion fixed to the apparatus being locked, for example a door, and having the electromagnet therein, has the advantage that the power supply and processor associated with the electromagnet can also be fixed and do not need to move reducing the complexity of the apparatus.

The first body portion may comprise a sliding bolt and said second body portion comprises a lock body within which said sliding bolt moves.

Alternatively, the first body portion may comprise a plug in a cylinder lock and said second body portion comprises a barrel.

In a preferred embodiment the power to operate said processor and said electromagnet is provided from the key.

In another preferred embodiment the different directions are opposite directions.

By having the shuttles move in opposite directions the advantage is provided that the arrangement of the shuttles and electromagnet is simple allowing a straightforward electromechanical lock to be produced.

Preferred embodiments of the present invention will now be described, by way of example only, and not in any limitative sense with reference to the accompanying drawings in which Figure 1 is a schematic representation of a locking device of the present invention.

The locking device 10 shown in figure 1 is an example of a sliding bolt lock. The device 10 includes a first lock portion, in the form of a fixed portion 12 a second lock portion in the form of a sliding portion 14, which can also be referred to as a bolt. The fixed and sliding portions 12 and 14 are able to move relative to one another and the junction between them, that is where their respective joining faces contact each other, the forms a pair of shear lines 16 and 18. An electromagnet 20 is formed in the fixed portion 12 and includes a ferromagnetic core 22 which is surrounded by a coil 24 for generating an electromagnetic field when power is supplied to it via the connecting wires 26 and 28. Also contained in the fixed portion 12 are a processor 30 and a key socket 32 which includes a pair of signal receivers 34 and 36 and is connected to the processor via connecting cables 38 and 40. The processor 30 is connected to the electromagnet 20 via the connecting wires 26 and 2 8.

The sliding portion 14 is shaped to fit around the fixed portion 12 with a pair of arms 42 and 44 extending from connecting body 46 which is attached to a latch 48. In each of the arms 42 and 44 of the sliding portion 14 there is a recess (labelled 50 and 52). Also forming part of the locking device 10 are a pair of shuttles 54 and 56 which are associated with the recesses 50 and 52. Each of the shuttles 54 and 56 contains a permanent magnet which are arranged such that the pole of the magnet in the shuttle which is closest to the electromagnet 20 is the same as the pole produced at that end of the electromagnet. As a result, when the electromagnet is powered the shuttles are repelled away from the electromagnet and further into the recesses 50 and 52. However, because the electromagnet has a ferromagnetic core 22 when no power runs through the coil 24 the permanent magnets within the shuttles are attracted towards the core. It is preferable, as shown in figure 1, that the core 22 of electromagnet 20 extends slightly beyond the ends of the coil 24 so that the shuttles 54 and 56 can engage the core 22. To protect the whole device from interference, and in particular the shuttles 54 and 56 and the electromagnet 20, a housing (not shown) encloses the device, although allowing at least the latch 48 to extend therefrom. It is preferable that the housing is made from a ferromagnetic material such as steel. It might be considered possible to overcome the lock by attracting the permanent magnets in the shuttles towards other magnets placed against the lock. However, where a steel housing has been used this will not work since the ferromagnetic housing then acts as a Faraday cage. The external magnets are attracted to and attached to the steel housing and do not affect the shuttles.

The locking device 10 operates between locked and unlocked conditions and in the locked condition the shuttles 54 and 56 straddle the shear lines 16 and 18. In order to allow the shuttles to straddle the shear lines recesses are also present in the fixed portion 12, as indicated at 58 and 60. These recesses are not as deep as the recesses 50 and 52 which are large enough to receive the whole of the shuttles 54 and 56. These recesses in the fixed portion are not an essential feature of the invention as there are other mechanisms (explained below) which allow the straddling of the shear line by the shuttles.

In order to facilitate easy operation of the locking device 10 a pair of springs 62 and 64 are provided to bias the sliding portion 14, and therefore the latch 48, towards the locked position where the latch is located in an aperture or recess 66 in a doorjamb 68 which is preferably bound by a strike plate (not shown).

The locking device 10 is operated by a key 70 which has a housing 72 containing a battery 74 and a processor and signal producer 76. The signal is transferred via key contacts 78 and 80 which engage the signal receivers 34 and 36.

Operation of the locking device 10 will now be described. The locking device is shown in figure 1 in a locked condition. The latch 48 is located in the apertures 66 thereby preventing the door from opening. Because the shuttles 54 and 56 are attracted to and engage the core 22 of the electromagnet 20 they are contained partially within the recesses 58 and 60 in the fixed portion and extend partially into the recesses 50 and 52 in the sliding portion 14, the shuttles straddle the shear lines 16 and 18 thereby preventing the sliding portion 14 moving relative to the fixed portion 12. Specifically, if the sliding portion 14 attempts to move in the direction DI, thereby compressing the springs 62 and 64, the shuttles jam in the recesses. Using the shuttle 54 as an example, the right-hand edge 82 of the shuttle 54 is pushed by the right-hand edge 84 of the recess 50 thereby causing the left-hand edge 86 of the shuttle 54 to engage the left-hand edge of the recess 58. As a result, the shuttle 54 is jammed in the recesses 50 and 58 and by a similar mechanism the shuttle 56 is jammed in the recesses 52 and 60.

To unlock the locking device 10, the key contacts 78 and 80 of key 70 are brought into engagement with the signal receivers 34 and 36. This causes the processor 76 to generate a signal and transmit this signal to the processor 30. The power for the processor 30 come from the battery 74. If the signal received by the processor 30 is correct current, also originating from the battery 74, powers the electromagnet 22 thereby generating a magnetic field which repels the magnets in the shuttles 54 and 56 causing them to move in opposite directions and into the recesses 50 and 52. Because the shuttles 54 and 56 fit entirely within the recesses 50 and 52 they no longer straddle the shear lines 16 and 18 and do not restrict the movement of the sliding portion 14 relative to the fixed portion 12. As a result, if a force is applied to the sliding portion in the direction DI (via a handle not shown or by applying a sliding force to the key socket 32) the sliding portion 14 is able to compress the spring 62 and 64. As the sliding portion 14 moves in the direction DI, the recesses 50 and 52 are no longer aligned with the recesses 58 and 60 and the magnetic field generated by the electromagnet 20 is less able to force the shuttles into the recesses. As a result, one or more of the shuttles may, under the influence of gravity, move towards the fixed portion 12. However, because the shuttles are no longer over the recesses 58 and 60 in the fixed portion 12 they engage the side of the fixed portion and cannot straddle the shear lines 16 and 18. Typically, the power is held on for between 2 and 5 seconds and this time limiting is achieved by the software running in the processor.

When the sliding portion 14 is released the springs 62 and 64 force the sliding portion in the direction D2. Once the key 70 has been removed the power to the electromagnet is cut and the shuttles, once aligned with recesses 58 and 60 are attracted to the ferromagnetic core 22 causing them to enter the recesses and straddle the shear lines 16 and 18 thereby locking the device .

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 departure from the scope of the protection which is defined by the appended claims. For example, the recesses 58 and 60 could be removed from the fixed portion 12 and instead the device operating with the core 22 of the electromagnet 20 extending further towards the shear lines 16 and 18. In addition the shuttles 54 and 56 are provided with recesses into which the ends of the core 22 fit. As a result, the shuttles extend across the shear lines and are prevented from moving in the direction DI when the sliding portion 14 moves in that direction because the recesses in the shuttles are engaged around the ends of the core 22.

In further alternatives, the arrangement of the fixed and sliding portions can be altered. For example, the sliding portion could be located in the middle with the fixed portion on the outside. In a further alternative the location of the electromagnet and the recesses 50 and 52 can be switched with the electromagnet in the moving portion and the recesses in the fixed portion. With some arrangements it may be necessary to provide multiple electromagnets in order to make this orientation work. Although this is less desirable than using a single electromagnet it would still fulfil the same functional requirements of the invention.

Although the arrangement described above, with reference to figure 1, is desirable with the shuttles operating in opposite directions, this is not the only arrangement which would be functional for the present invention. For example, a non-linear electromagnet would in principle work as long as the shuttles are required to move in different directions they do not need to be in opposite directions.

The mechanism of electromagnet and shuttles extending into recesses would also work in a cylinder type lock. In this instance the fixed portion would be the barrel of the cylinder and the sliding portion would be the plug which utilises a rotational slide to perform that function. It is also possible that this mechanism could be used in conjunction with a manual lock. For example, a Euro cylinder, or similar device, could be provided with the standard manual parts and in addition the electromagnet, shuttles and recesses of the present invention which could be controlled from and powered by the key. In a further alternative, the lock may include a power supply which

- 9 powers the processor and electromagnet and may be used to provide power to a key to extract a code signal therefrom. In a further variation to this alternative the processor may include a Bluetooth receiver which receives the key code signal from a 5 Bluetooth transmitter device, such as a mobile phone, or from a passive code producing device such as an RFID tag.

Claims

1. A locking device comprising:- at least one first lock portion;

at least one processor for receiving and processing a signal from a key associated with said locking device, the processor causing a current to pass through said electro magnet, wherein in response to a correctly coded said signal to said processor the locking device switches from a locked condition, in which said shuttles are attracted to said ferromagnetic core and straddle said shear line, to an unlocked condition, in which power is sent to said electromagnet thereby generating a magnetic field repelling said shuttles in different directions into said recesses and no longer straddling said shear line, thereby allowing movement of said first and second lock portions relative to each other.

2. A device according to claim 1, wherein said first body portion is in use fixed relative to an apparatus being locked and said second body portion is moveable relative to said apparatus .

3. A device according to claim 1 or 2, wherein said first body portion comprises said at least one electromagnet and said second body portion comprises said recesses.

4. A device according to any of claims 1 to 3, wherein said first body portion comprises a sliding bolt and said second body portion comprises a lock body within which said sliding bolt moves .

5 5. A device according to any of claims 1 to 3, wherein said first body portion comprises a plug in a cylinder lock and said second body portion comprises a barrel.

6. A device according to any preceding claim, wherein power to operate said processor and said electromagnet is provided

10 from the key.

7. A device according to any preceding claim, wherein said different directions are opposite directions.