GB2510590A

GB2510590A - Locking security plug

Info

Publication number: GB2510590A
Application number: GB201302205A
Authority: GB
Inventors: Adam Theobald
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-02-07
Filing date: 2013-02-07
Publication date: 2014-08-13
Also published as: GB201302205D0

Abstract

A locking plug for a socket (e.g micro-USB socket) of an electronic device comprises an insertable portion 14 for insertion into the socket and a handle portion 16 which remains outside of the socket. The insertable portion 14 has a plurality of electrical contacts for the transfer of electrical power and/or information. The insertable portion 14 has a wall 20 provided with an aperture 28. A locking projection is moveable between a first, locking position, in which the locking projection 76 projects outwardly of the wall 20 through the aperture 28, and a second, retracted position. A sliding locking member 56 has a first end, located in the handle portion 16, and a second end, which operates the locking projection 76. The sliding locking member 56 is slideable by operation of the first end between a first position, in which the second end locks the locking projection 76 in the first, locking position, and a second position, in which the locking projection 76 is allowed to move to the second, retracted position.

Description

SECURITY DEVICE

The invention relates to a plug for a socket of an electronic device, to a security restraint for an electronic device and comprising the plug. to a kit comprising the plug and a security key for operation of the plug, and to an assembly comprising the plug or the security restraint and an electronic device.

It is desirable to allow potential purchasers to handle and operate portable electronic devices, such as smart phones, on display during retail sale, while avoiding theft of the devices. One known security restraint for retail display comprises a cradle which fits around the device and which is secured to a display stand by a cable. However, the cradle tends to impede operation of the electronic device and prevents the potential purchaser from assessing the feel and weight of the electronic device.

A less obtrusive and less obstructive type of security restraint is disclosed in WO 2012/160168. This document discloses a jack plug that has an insertable portion (or pin) that can be expanded while inserted within a jack socket of an electronic device to jam the insertable portion within the socket. WO 2012/160168 also discloses a mini-USB plug that has an insertable portion which is expandable within a rnini-USB socket to jam the plug within the socket. In both cases, expansion of the insertable portion is achieved by advancing a screw into the insertable portion to splay the insertable portion. Plugs of this type are attached to a display stand by a cable.

According to a first aspect of the invention, there is provided a plug for a socket of an electronic device, the plug having an insertable portion for insertion into the socket and a handle portion which remains outside of the socket, the insertable portion having a plurality of electrical contacts for the transfer of electrical power and/or information, the insertable portion having a wall provided with an aperture, a locking projection moveable between a first locking position in which the locking projection projects outwardly of the wall through the aperture and a second retracted position, and a sliding locking member, the sliding locking member having a first end located in the handle portion and a second end which operates the locking projection, the sliding locking member being slideable by operation of the first end between a first position in which the second end locks the locking projection in the first locking position of the locking projection and a second position in which the locking projection is allowed to move to the second retracted position of the locking projection.

With the locking mechanism utilised in the plug of the current invention, it is easier to provide a plug that has both the ability to lock within a socket and also the ability to transmit electrical power and/or information. For example, the plug of the current invention may be a rnicro-USB plug that can be locked within a USB socket and which has the same capability of standard rnicro-USB plug to transmit electrical power and information.

In accordaice with a second aspect of the invention, there is provided a security restraint for an electronic device comprising a plug according to the first aspect of the invention and a cable connected to the handle portion of the plug, the cable being electrically connected to the plurality of electrica' contacts for transmission of electrical power and/or information.

The cable may include a reinforcement such as a sheath of metal braiding or polymer to resist snapping or cutting of the cable.

In accordance with a third aspect of the invention, there is a provided a kit comprising a plug according to the first aspect of the invention, the handle portion of the plug having a security lock lockable to lock the sliding locking meniber in the first position of the sliding locking member, and a security key, the security lock being unlockable substantially only by using the security key.

in accordance with a fourth aspect of the invention, there is provided an assembly comprising a plug according to the first aspect of the invention, or a security restraint according to the second aspect of the invention, together with an electronic device having a socket, the insertable portion of the plug being insertable into the socket and being locked in the socket when the locking projection is in the first locking position.

The following is a more detailed description of embodiments of the invention, by way of example, reference being made to the appended schematic drawings in which: Figure 1 is a perspective view from above of a locking plug with an upper half of a plastics casing having been removed; Figure 2 is a plan view from above of the plug of Figure 1 in which the upper half of the plastics casing has also been removed; Figure 3 is a plan view from above of the plug of Figures 1 and 2 in which the upper half of the plastics casing is shown in position; Figure 4 is a side elevation showing a left side of the plug of Figures ito 3; Figure 5 is a side elevation showing a right side of the plug of Figures 1 to 4; Figure 6 is a partial cross-sectional view of the plug of Figures 1 to 5 showing the plug in a locking configuration; Figure 7 is a partial cross-sectional view showing the plug of Figures 1 to 6 in an unlocked configuration; Figure 8 shows an elongate member from the p'ug of Figures 1 to 7; Figure 9 shows, by way of comparison, a standard micro B USB plug (which is not in accordance with the invention) in engagement with a standard micro B USB socket; Figure 10 shows the standard micro B USB plug of Figure 9 being withdrawn from (or inserted into) the standard micro B USB socket; Figure II shows an alternative plug, in accordance with the invention, in a locking configuration, locked within a standard micro B USB socket; and Figure 12 shows the alternative plug of Figure 11 in an unlocking configuration, the plug being withdrawn from (or inserted into) the standard micro B USB socket.

Referring first to Figures 1 to 5, the locking plug 10 is provided with a cable 12 which is securely fixed to the plug 10 in a manner described below. The cable 12 has a braided outer sheath (not shown) which makes the cable resistant to cutting or snapping. The cable 12 also has five independently insulated core wires (not shown). At an end of the cable 12, remote from the plug 10, the cable 12 is provided with a loop (not shown) or with some other formation enabling the cable 12 to be readily secured to a display stand (not shown).

The plug 10 has an insertable portion 14 and a handle portion 16. The insertable portion 14 has an outer metal casing 18 which is formed as a loop so as to have a first side wall 20, a second side wall 22 which lies opposite and parallel to the first side wall 20 and two edge walls 24, 26 which connect the first and second side walls 20, 22. The first side wall 20 is provided with two apertures in the form of slots 28, 30.

The outer profile of the outer metal casing 18 is identical to that of a standard micro B USB plug. The two apertures 28, 30 are identical to corresponding apertures provided in a standard micro B USB plug.

Although not shown in the drawings, the insertable portion 14 of the plug 10 is provided with five electrical contacts, located within the outer metal casing 18, which are identical in configuration and in position to the five electrical contacts of a standard micro B USB plug.

The five electrical contacts are connected, respectively, to the five core wires of the cable 12 (the connection not being shown in the Figures). However, unlike a standard micro B USB plug, the insertable portion 14 of the p'ug 10 also houses components of a locking mechanism which allows the insertable portion 14 to be locked in position, while inserted in a standard micro B USB socket, to prevent removal of the plug 10 from the socket.

The handle portion 16 of the plug 10 is generafly triangular in shape and has an outer plastics casing formed by an upper casing half 32 and a lower casing half 34. The upper casing half 32 and the lower casing half 34 are readily connected to one another and also separated from one another by any suitable mechanism. An inner metal frame 36 is secured within the lower casing half 34 and serves to strengthen the handle portion 16.

As seen best in Figure 1, the insertaNe portion 14 of the plug 10 extends outwarffly from a front wall 38 that is provided by the inner metal frame 36. The outer plastics casing 32, 34 foirns a left side waIl 40 and a ñght side wall 42. The left side waIl 40 is provided with a left side aperture 44 which serves a purpose to be described below. The right side wall 42 is provided with a right side aperture 46 through which passes the cable 12.

Referring now to Figures 1 and 2, the handle portion 16 of the plug 10 has a security lock 48 which takes the form of a block of metal formed integrally with the inner metal frame 36 and which is provided with a threaded aperture 50 which passes fully across the security lock 48 and which receives a locking screw 52. As best seen in Figure 1, the threaded aperture 50 and the locking screw 52 are aligned with the left side aperture 44 to allow operation of the locking screw 52.

The head of the locking screw 52 is provided with a security formation 54. As seen in Figure 4, the secunty formation 54 takes the foim, in this particular embodiment, of a pyramidal projection. The security formation 54 can be engaged by a pyramidal recess having a corresponding shape to the security formation 54 and provided on a security key (not shown).

It will be appreciated that the security formation 54 need not take the form of a pyramidal projection and may have any shape which allows the security formation 54 to be engaged by a correspondingly shaped security key so as to allow the locking screw 52 to be rotated. The security formation 54 need not be a projection. It could be a recess which engages with a corresponding projection on the security key. In particular, the security formation 54 may have any configuration that is not readily engaged by a standard slot or cross-head screw driver. The term security key, as used herein, refers to any key that is capable of engaging such a security formation so as to rotate the locking screw 52.

The plug 10 houses a sliding locking member 56 consisting of a button 58 and two metal rods 60, 62 which are fixed in the button 58. The button 58 can be readily operated, once the upper casing half 32 has been removed, by either a finger or a finger nail so as to sfide the sliding locking member 56 either backward or forward (as best seen in Figures 6 and 7). The button 58 is also provided with a recess 64 which serves a purpose to be described below.

The handle portion 16 of the plug 10 also houses a guide and mounting block 66 (see Figures I and 2) which serves various purposes. The guide and mounting block 66 serves to mount the outer metal casing 18 of the insertable portion 14. lii addition, the two metal rods 60, 62 of the sliding locking member 56 pass through an aperture (or alternatively through respective apertures) in the guide and mounting block 66 and this serves to guide the two metal rods 60, 62 so that they are constrained to move in a forward and backward direction. It will be noted that the guide and mounting block 66 is omitted from Figures 6 and 7 simply for clarity of representation. The five core wires of the cable 12 also pass through the guide and mounting block 66 for connection with the electrical contacts of an insertable portion 14.

The guide and mounting Hock 66 also serves to mount other components of the plug 10, as discussed Mow.

As seen in Figures 1, 2, 6 and 7, the handle portion 16 of the plug 10 is also provided with a stop 68 which serves to limit the rearward movement of the sliding locking member 56. Once the button 58 contacts the stop 68, no further rearward movement is allowed.

As best seen in Figures 6 and 7, the plug 10 also has two elongate members 70, 72. The two elongate members 70, 72 are identical to one another and so only the elongate member 70 which is shown in Figures 6 and 7 will be described in detail. The dongate member 70 is also shown, in isolation, in Figure 8.

The elongate member 70 has a mounting portion 74 and a locking projection 76. The mounting portion 74 and the locking projection 76 are connected by an elongate connecting portion 78.

The mounting portion 74 is mounted in the guide and mounting block 66 in such a manner so as to allow the elongate member 70 to move, in a manner akin to pivoting, from the position shown in Figure 6 to the position shown in Figure 7. In the position of the elongate member shown in Figure 6, the locking projection 76 projects outwardly through the aperture 28.

In the position of the elongate member 70 shown in Figure 7, the locking projection 76 is retracted and lies frilly within the outer metal casing 18. As shown in Figure 6, 7 and 8, the locking projection 76 has a first inclined surface 80 which faces generally towards the front wall 38 of the handle portion 16. The first incline surfaced 80 meets a second incfined surface 82 which faces generally upwards and away from the front wall 38.

As best seen in Figures 1 and 2, the end of the cable 12 that connects to the plug 10 is provided with an outwardly extended flange 84. The cable flange 84 is retained by a retaining formation 86 formed integrally with the inner metal frame 36. In this way, the cable 12 is securely fixed to the plug 10.

As discussed above, the outer profile of the outer metal casing 18 of the plug 10 is identical to the outer profile of an insertable portion of a standard micro B USB plug. Figures 9 and 10 show a standard micro B USB plug 90 fully inserted and partially inserted, respectively, into a standard micro B USB socket 92. As shown in Figures 9 and 10, the standard micro B USB plug 90 has an insertable portion 94 and a handle portion 96. Two resiliently flexible retaining pins (one of which is shown at 98) are mounted in the handle portion 96 and extend into the insertable portion 94. Each resiliently flexible pin 98 has a rounded end portion 100.

The natural position of each resiliently flexible pin 98 is the position shown in Figure 9. As seen in this figure, each resiliently flexible pin 98 is resiliently urged into an angled position against a side wall of the insertable portion 94, such that the rounded end porion 100 of the pin 98 projects through a corresponding aperture i02 in the side wall of the insertable portion 94.

The rounded end portions 100 of the standard micro B USB plug 90 engage with a slot 104 within the standard micro B USB socket 92 and this helps to retain the standard p'ug 90 in the standard socket 92. However, the standard plug 90 does not lock within the standard socket 92 and can be readily disengaged from the standard socket 92 by pulling the plug 90 whereupon the resilient retaining pins 98 flex and the two rounded end portions 100 disengage from the slot 104 in the standard socket 92. This is assisted by the rounded profile of the rounded end portions iOO. Withdrawal of the standard micro B USB plug 90 from the standard socket 92 (or alternatively insertion of the plug) is shown in Figure 10 which shows the flexed (or stressed) position of the resilient flexible retaining pins 98.

In contrast to the operation of a standard micro B USB plug 90, the plug 10 of the current invention can be operated so as to lock the plug 10 in a standard micro B USB socket 92.

This is done as follows.

Before insertion of the insertable portion 14 of the plug 10 into the standard micro B USB socket 92, the button 58 is moved fully rearwardly, to the position shown in Figure 7. so that the button 58 contacts the stop 68. With the button 58 in this position, the two metal rods 60, 62 oMy extend a short distance into the insertable portion 14. The elongate members 70, 72 are positioned as shown in Figure 7 so that the locking projections 76 of the elongate members 70, 72 are retracted within the outer metal casing 18. The insertable portion 14 of the plug 10 is then inserted into the standard micro B USB socket 92 (the standard socket 92 being shown in Figures 9 and 10).

After insertion, the button 58 is moved forwardly which causes the two metal rods 60. 62 to move into the insertable portion 14, to the positions shown in Figure 6. Each one of the two metal rods 60, 62 contacts a respective one of the two elongate members 70, 72 and the movement of the two metal rods 60, 62 into the insertable portion 14 causes the two elongate members 70, 72 to move into the position shown in Figure 6. In this position, the two locking projections 76 project. respectively, through the two apertures 28, 30. As will be seen in Figures 1 and 6, each locking projection 76 extends outwardly of the side wall 20. The two locking projections 76 enter into the slot 104 that is provided within the standard micro B USB socket 92 (the same slot 104 which normally receives the rounded ends 100 of a standard micro B USB plug 90).

The two elongate members 70, 72 are now held firmly in the position shown in Figure 6. as each elongate members 70, 72 is sandwiched, on one side, by the first side wall 20 and, on the other side, by respective one of the two metal rods 60, 62. lii turn, each one of the two metal rods 60. 62 is sandwiched between the second side wall 22 and a respective one of the two dongate members 70, 72. As shown in Figure 6. each one of the elongate members 70, 72, together with the corresponding adjacent metal rod 60, 62, takes up substantially all of the space between the first side wall 20 and the second side wall 22. In this way, the elongate members 70, 72 are locked in the position shown in Figure 6 and the locking projections 76 cannot be retracted. In this position, the first inclined surfaces 80 of the locking projections 76 engage the slot 104 in the standard micro B USB socket 92 and this prevents withdrawal of the insertable portion 14 from the standard socket 92.

In the locking position described above and shown in Figure 6, the recess 64 of the button 58 is aligned with the threaded aperture 50 of the security lock 48. A security key (not shown) is engaged with the security formation 54 on the locking screw 52 and the security key is used to rotate the locking screw 52 so that the end of the locking screw 52 passes into the recess 64. In this way, the button 58 is prevented from moving rearwardly and the plug 10 is locked in the locking configuration.

Finally, the upper casing half 32 is connected to the lower casing hall 34.

As discussed above, the plug 10 has five electrical contacts in the insertable pordon 14 which are connected. respectively, to the five core wires in the cable 12. These parts of the plug 10 function in an identical manner to the conesponding parts of a standard micro B USB plug and so the plug 10 and the cable 12 can be used to supply electrical power to the electronic device in which the plug 10 is locked. By way of example, the electronic device may be a smart phone used as a demonstrator in a retail outlet. The smart phone is maintained charged by electrical power supplied via the cable 12 and the plug 10. The fact that the plug 10 is locked within the standard micro B USB socket 92 of the smart phone, and the fact that the cable 12 is secured to a display stand in the retafi outlet, helps to prevent theft of the demonstrator model. If desired, electronic information can be passed into or out of the smart phone via the plug 10 and the cable 12.

As discussed above, the locking screw 52 of the security lock 48 can only be operated by a security key having a correspondingly shaped formation to that of the security formation 54.

The security formation 54 can be chosen so as to make it unlikely that any potential thief would be carrying a compatible security key.

When it is desired to unplug the electronic device from the plug 10, the upper casing half 32 is first removed and the security key is then used to unscrew the locking screw 52.

KAltematively, the locking screw 52 can be unscrewed by passing the security key through the left side aperture 44 without removing the upper casing half 32.) This allows the button 58 to be slid rearwardly until the button 58 contacts the stop 68. In turn, this withdraws the two metal rods 60. 62 from the insertable portion 14 into the handle portion 16. The sliding locking member 56 is now in the position shown in Figure 7. As shown in Figure 7, the two metal rods 60, 62 no longer serve to lock the two elongate members 70, 72 in the locking position shown in Figure 6. In the unlocked position shown in Figure 7, the locking projections 76 can be readily retracted into the outer metal casing 18 and this allows the plug to be disengaged from the standard micro B USB socket 92 of the electronic device.

It will be appreciated that many adaptations may be made to the plug 10 described above without departing from the scope of the invention as defined in the claims.

An alternative locking micro B USB plug 110 is shown in Figures 11 and 12. Features of the alternative plug 110 shown in Figures 11 arid 12, which are identical to, or which differ in insignificant details from, corresponding features of the plug 10 described above, are not described in detail and will be given the same names and reference numerals to the corresponding features from the plug 10.

The alternative plug 110 differs from the plug 10 mainly in the design and operation of the elongate members. In the alternative p'ug 110, the elongate members 70, 72 of the plug 10 are repbced with resiliently flexible elongate members (one of which is shown at 112). Each resiliently flexible elongate member 112 has a mounting portion 116 and a locking projection 118. The mounting portions 116 are rigidly mounted in the guide and mounting block 66 -so as to prevent pivoting movement of the resiliently flexible dongate members 112. Instead of pivoting, each resiliently flexible dongate member 112 moves between a locking position and a retracted position by flexing. The relaxed shape of each resiliently flexible elongate member 112 is the shape shown in Figure 12 in which the resiliently flexible elongate member 112 is bent so that the locking projection 118 is retracted into the insertable portion 14. When the sliding locking member 56 is moved forwardly. into the locking position shown in Figure 11, each metal rod 60, 62 bears against a corresponding one of the resiliently flexible elongate members 112 to force the elongate member 112 into the stressed position shown in Figure 11. in which the corresponding locking projection 118 projects outwardly from the insertable portion 14. In the locking configuration shown in Figure 11, the locking projections 118 engage with the slot 104 in a standard micro B USB socket 92 so as to lock the plug 110 within the standard socket 92 and prevent withdrawal.

The alternative micro B USB plug 110 also differs from the plug 10 described above in that the alternative plug 110 has an upper casing half 120 which is mounted on the button 58. The sliding locking member 56 is moved between the locking and unlocking positions by sliding the upper casing half 120 backwards and forwards, as shown in Figures 11 and 12. The movement of the upper casing half 120 moves the sliding locking member 56 backwards and forwards between the locking and unlocking positions in view of the mounting of the upper casing half 120 on the button 58.

In the alternative plug 110 shown in Figures 11 and 12, it is important that the two resiliently flexible elongate members 112 do not become permanently deformed when they are flexed into the locking position described above, In order to prevent permanent deformation of the resiliently flexible elongate members 112, the elongate members 112 shou'd be of a sufficient length so that the degree of flexing, when spread over the length, does not result in permanent deformation. For example, the length of each resiliently flexible elongate member 112 may be greater than 5mm. and preferably 7mm. Similarly. the extent of movement of the two metal rods 60, 62 from the locked position to the unlocked position may be also be greater than 5mm, and preferably about 7mm.

As discussed above, each one of the two locking projections 76, 118 has a first inclined surface 80 and a second inclined surface 82. The first inclined surface 80 engages with the retaining slot 104 in the standard micro B USB socket 92 and prevents removable of the plug 10, 110 from the socket 92. Alternativdy, however, the locking projections 76, 118 may have any other shape that is suitable for locking with the slot 104 of the standard micro B USB socket 92 so as to prevent removable of the locked plug 10, 110 from the socket 92.

In the two inventive plugs 10, 110 described above, the security lock 48 is a simple mechanical arrangement comprising a screw 52 that can be engaged with a recess 64.

However, any form of security lock may be used. The security lock can be mechanical, electrical or utilise a combination of the two.

Claims

CLAIMS1. A plug for a socket of an electronic device, the plug having an insertable portion for insertion into the socket and a handle portion which remains outside of the socket, the insertable portion having a plurality of electrical contacts for the transfer of electncal power and/or information, the insertable portion having a wall provided with an aperture, a locking projection moveable between a first locking position in which the locking projection projects outwardly of the wall through the aperture and a second retracted position, and a sliding locking member, the sliding locking member having a first end located in the handle portion and a second end which operates the locking projection, the sliding locking member being slideable by operation of the first end between a first position in which the second end locks the locking projection in the first locking position of the locking projection and a second position in which the locking projection is allowed to move to the second retracted position of the locking projection.
2. A plug according to claim 1, wherein the locking projection is provided at a first end of an elongate member which has a second end mounted in the handle portion, the elongate member having a first operating state in which the locking projection is in the first locking position and a second operating state in which the locking projection is in the second retracted position, the second end of the sliding locking member interacting with the elongate member so that sliding movement of the sliding locking member from the second position of the sliding locking member to the first position of the sliding locking member causes the elongate member to change from the second operating state to the first operating state and sliding movement of the sliding locking member from the first position of the sliding locking member to the second position of the sliding locking member allows or causes the elongate member to change from the first operating state to the second operating state.
3. A plug according to claim 2, wherein said wall of the insertable portion is a first external wall of the insertaHe portion and the insertable portion has a second external wall opposite to the first external wall, the elongate member lying adjacent the first external wall and the sliding locking member moving between the elongate member and the second external wall and wherein in the first position of the sfiding locking member the sliding locking member is held in contact with the elongate member by the second external wall.
4. A plug according to claim 2 or claim 3, wherein the elongate member is resiliently flexible and the first and second operating states of the elongate member are first and second configurations of the elongate member, respectively, sliding movement of the sliding locking member from the second position of the sliding locking member to the first position of the sliding locking member forcing the elongate member to flex from the second operating state to the first operating state, sliding movement of the sliding locking member from the first posifion of the sliding locking member to the second position of the sliding locking member allowing the elongate member to resiliently revert from the first operating state to the second operating state.
5. A plug according to claim 2 or claim 3, wherein the first and second operating states of the elongate member are first and second positions of the elongate member, respectively, said mounting of the second end of the elongate member in the handle portion allowing movement of the elongate member between the first and second positions thereof
6. A plug according to any preceding claim, wherein the first end of sliding locking member is formed as a button to facilitate manual sliding operation of the sliding locking member.
7. A plug according to claim 6, wherein the sliding locking member comprises a rod fixed in the button, an end of the rod forming the second end of the sliding locking member.
8. A plug according to claim 7, wherein the handle portion comprises a guide provided with a hole, the rod extending through the hole whereby the guide constrains the movement of the sliding locking member to movement in the direction of the hole.
9. A plug according to any preceding daim, wherein the handle portion has a security lock lockable to lock the sliding locking member in the first position of the sliding locking member, the security lock being unlockable substantially only by using a security key.
10. A plug according to claim 9, when daini 9 is dependent on any one of claims 6 -8.wherein the button has a recess, the security lock comprising a screw operable by a secunty key to engage the screw with and disengage the screw from the button recess.
11. A plug according to any preceding claim, wherein the insertable portion fits within and interfaces with a micro-USB socket for the transfer of power and/or information between the plug and the socket, the inset-table portion being locked within the socket when the locking projection is in the fr-st locking position.
12. A security restraint for an electronic device comprising a plug according to any preceding claim and a cable connected to the handle portion of the plug, the cable being electrically connected to the plurality of electrical contacts for transmission of electrical power andlor information.
13. A security restraint according to claim 12, wherein the cable has a formation allowing the cable to be fixed to a shop fixture.
14. A kit comprising a plug according to claim 9, or any claim dependent on claim 9. and a security key for operation of the security lock.
15. An assembly comprising a plug according to any one of claims 1 to II. or a security restraint according to claim 12 or clam 13, and an electronic device having a socket, the insertable portion being insertable into the socket and being locked in the socket when the locking projection is in the first locking position.
16. An assembly according to claim 15, wherein the dectrical contacts of the plug interface with electrical contacts of the socket for the transmission of electrical power andlor information.
17. A plug substantially as hereinbefore described with reference to Figures 1 -8 or Figures II and 12.
18. A security restraint comprising a plug and a cable substantiafly as hereinbefore described with reference to Figures 1 -8 or Figures II and 12.