GB2500979A

GB2500979A - Lock assembly with key retaining aperture

Info

Publication number: GB2500979A
Application number: GB1303014.3A
Authority: GB
Inventors: Anthony Molloy
Original assignee: Individual
Current assignee: Individual
Priority date: 2012-02-24
Filing date: 2013-02-21
Publication date: 2013-10-09
Anticipated expiration: 2033-02-21
Also published as: GB201203252D0; GB201303014D0; GB2500979B

Abstract

A lock assembly comprising: a lock housing 14 within which is mounted a shaft 18 having at a key head portion 19 with a key receiving aperture at one end and a latch 24 mounted to the shaft at the other end moveable between a locking portion and a unlocking position and a biaser to bias the shaft in the unlocked position; a key cover 12 at the key end of the housing having an aperture 16 wherein in the unlocked position of the shaft the key head portion is at least partially obscured/misaligned by the key cover, thus preventing removal of a key/tool 30 from the lock in the unlocked position. The housing may have a cutout portion 15 with edges 17 preventing rotation of the shaft/latch, preferably the shaft requires sliding/axial movement prior to rotation to unlock, the biaser may be a helical spring resisting compressing and axial displacement of the shaft away from the unlocked position and may also be a torsion spring resisting rotation. The lock may be used in a manhole cover.

Description

Lock Assembly The present invention relates to a lock assembly, particularly but not exclusively for use in the locking of street and road covers such as manhole covers and telephone exchange covers, as well as to covers having such a lock assembly or assemblies and key holders therefor.

In streets and roads, and both on and off pavements, there are typically a number of covers adapted to provide access thereunder) such as to services such as for telephones, gas) water, etc., as well as covers for deeper access to underground locations. These are often generally termed "manhole covers", but include covers for access under streets, under roads) under pavements or the like.

Many such covers are now locked', either directly or indirectly, to prevent unauthorised access, and particularly to prevent vandalism, usually by adventurous youngsters. However, such people still seek to undo such locks as part of the adventure. Meanwhile, manhole covers are not intended to be complex and costly items, negating the use of sophisticated locking assemblies and mechanisms.

A known lock has an integral triangular key-head for opening by insertion of a corresponding triangular key designed to open the lock, for subsequent lifting of the cover by lifting rods from its road-or street-aligned position to gain access thereunder.

However, such locks cannot confirm whether they have been left in their locked or open positions after use, leading to possible accidentally unlocked covers.

Moreover, such locks only require simple turning to achieve their opening.

It is an object of the present invention to provide an improved lock assembly, easily able to be used as part of conventional manhole cover manufacture.

According to one aspect of the present invention, there is provided a lock assembly comprising: (a] a lock housing having a key end and a ktch end; (b) a shaft movealMe in the lock housing between a first locking position and second open position, the shaft having a key head comprising a key-head portion near the key end of the lock housing, and a latch end; (cJ a biaser to bias the shaft in its first locking position; (d] a ktch conjoined with the latch end of the shaft and moveable by the shaft between a first ocking position and a second open position; and (e] a key cover at the key end of the ock housing and above the key head of the shaft, the key cover having an aperture for access to the key-head portion, and wherein at least a portion of the aperture does not overlap with at least a portion of the key-head portion of the shaft when the shaft is in its second open position.

In this way, any key or key socket inserted through the aperture of the key cover to access and engage the key-head portion of the shaft (and thereby open' the lock] cannot be removed when the shaft is in its second open position.

The lock assembly may be in the form of a tubular-lock or a latch-lock.

The lock housing may be in the form of having a regular cross-section, for example being circular, square, etc, and/or having an elongate shape. Preferably, the lock housing has a first section suitalMe for partially, wholly or substantially housing the shaft, and also for partially, wholly or substantially accommodating the biaser between part of the lock housing and the shaft In one embodiment of the present invention, the lock housing has an outer wall section and at least one traverse section, the biaser being located between the traverse section and a head portion of the shaft Optionally, the shaft is straight, and extends directly from its key head at one end to the conjunction with the latch at its other end, and the latch is flat, or at least has a flat bottom or flat lowermost edge. PreferabW, the latch extends transversely from a lowermost end of the shaft Also optionally, the key cover is within the dimensions of the lock housing.

Preferably, the complete lock assembly is tess than 50mm in height or length) both in its open and closed positions. This allows the lock assembly to fit within the theight' dimensions of the most conventiona' or standard street covers currenUy manufactured and used, at least in the UK. Optionally, it is the height or ength of the lock housing which is less than 50mm, and the hitch is within this dimension, whether in its open or closed position.

The biaser could be fixed to the lock assembly at each end. Preferably, the biaser is fixed at one end to the shaft, and fixed at the other end to the one end to lock housing.

Optionally, the biaser is a spring, such as a helical spring. Preferably, the biaser is a torsion spring, and is preloaded or predisposed or otherwise arranged in the lock assembly to bias the shaft to its first locking position.

Preferably, the biaser provides biasing against the shaft moving in at kast a longitudinal direction a'ong the lock housing.

More preferably, the biaser also provides biasing against, and possilMy contrary to, rotation of the shaft from the first locking position to the second open position.

According to one embodiment of the present invention, the biaser biases the shaft to its first locking position following any compression of the biaser. In this way, if the lock assembly is accidentally topen, any unauthorised play with the lock assembly, such as trying to move the shaft with a device other than the correct key or key socket, will in fact cause it to close itself; and any similar unauthorised play when the lock assembly is already locked can only create movement of the shaft contrary to the action) such as the torsion, of the biaser.

In another embodiment of the present invention, the lock housing includes a second section able to partially, wholly or substantially house the latch) at east in its first locking position. Preferably, the latch is housed in the lock housing so as not to be moveable between its first and second positions without the latch being outside the lock housing That is, the ock housing is able to constrain or confine the latch in one or more recesses, or involves one or more projections or the like that prevent its unintentional movement between its first and second positions.

Optionally, any such first and section sections of the lock housing are formed integrally.

In another embodiment of the present invention, the latch is moveable between its first locking position and its second open position by longitudinal movement of the shaft through the lock housing and by rotation of the shaft about the lock housing, and vice versa.

Preferably, the shaft comprises a body having an enlarged head and a central column, the enlarged head including the key head, and including the key head portion. The key head portion may comprise one or more parts or sections, creating an overall key head shape having any suitable size, shape or design, radially, longitudinally or both. This includes having a regular or non-regular circumferential shape, and preferably includes at least a circumferential shape being generally oval, elliptical, polygonal, etc. For example, being in the form of an &ongate s'ot in the key head.

The key head shape should still provide at least some gripping force around its circumference, such that torque can be applied thereagainst for the movement thereof.

The key head portion may extend outwardly or inwardly relative to the remainder of the shaft and key head. That is, the key head may have a detent or be upstanding, convex or concave) or a combination of same, shape, when viewed from above or downwardly along the shaft The shaft is moveable between its first and second positions using a key or a key socket having a corresponding or complementary key-head shape at one end thereof. The corresponding or complementary key-head shape may be recessed into a key or key socket body, or extend outwardly from a key or key socket body, depending up on the arrangement of the key head portion on the shaft.

According to one embodiment of the present invention, the lock assembly of the present invention includes a key socket having a corresponding or complementary key-head shape to the key-head portion at one end thereof The key cover is preferably wholly or substantially at or near the key end of the lock housing, and optionally forms the top portion thereof, generally being that portion which is visible to the user.

The aperture in the key cover maybe the same or different to the shape of the key-head portion. Preferably, the circumferential shape of the aperture is slightly larger than the circumferential shape of the key-head shape, to provide some tolerance for entry of the corresponding or complementary key-head shape of the key or key socket body through the aperture prior to engagement with the key-head portion.

Thus, in one preferred embodiment of the present invention, the circumference of the aperture of the key cover is wholly or substantially in alignment with the circumference of the key head portion when the shaft is in its first locked position, so as to provide direct longitudinal access to the key-head portion through the aperture.

Alternatively, there may be some movement of the relevant key-head shape of the key or key socket body following its passage through the aperture of the key cover, prior to its engagement with the key-head portion.

Where the lock assembly is intended to be used with a key socket having a corresponding or complementary key-head shape at one end thereof, the other end of the key socket may have a socket-head shape that is corresponding or complementary to a key-head shape of a user key, such as being triangular or square, etc, and either being an outward projection, or a depression.

By having at least a portion of the aperture which does not overlap with at least a portion of the key-head portion of the shaft when the shaft is in its second open position, means that any complementary key or key socket inserted through the key cover and engaging the key-head portion will have at least a portion thereof located between the key end of the shaft and the key cover when the shaft is in its second open position. The key or key socket is therefore not separable or recoverable from the lock assembly when the shaft is in its second open position, (and hence when the lock assembly is open or unlocked, and any attachment to the lock assembly, in particular a cover, is therefore open or openable, etc].

Preferably, the relevant part of the key or key socket now out of alignment with the aperture, and located between the key head of the shaft and the underside of the key cover, is biased in that position by the biaser.

Thus, the visual existence of the key or key socket being held by or deemed within' the lock assembly indicates to a user that the lock assembly must be open, i.e. not closed or locked. In contrast, removal of the key or key socket is only possible when the shaft is in its first locking position.

In use, a user inserts a suitable key or key socket through the aperture of the key cover, and engages the end of the key or key socket with the key-head portion. By at least some rotation of the key or key socket against the biasing force of the biaser, movement of the shaft is possible between its first locking position and second open position.

Preferably, the biaser is biased against longitudinal movement and rotational movement of the shaft between a first locking position and a second open position.

In this way, the user requires the action of both rotational and longitudinal force through the key or key socket in order to move the shaft between its first locking position and its second open position.

The biaser may be any suitable device able to provide a biasing force, a non-limiting example being a spring, preferably a helical spring.

The lock assembly of the present invention is preferably arranged such that the unconnected end of the latch, the distal end, is locatable under or against a suitable, and usually permanent, corresponding frame, unit, device, location, etc., so as to prevent movement of the lock assembly, and therefore any apparatus, device, unit etc attached to the lock assembly, in at least one direction. The suitable unit, etc. may be a latch plate located in, on or otherwise about a frame or frame assembly surrounding the lock assembly and any attached apparatus, etc. One such frame assembly is a frame for a manhole cover.

The lock assembly of the present invention is preferably locatable within the key holder of a cover.

Thus, according to the second aspect of the present invention, there is provided a cover, such as a street or road cover, comprising one or more lock assembles as described herein. Preferably, the cover includes one or more key holders, and the or each lock assembly is located within an associated key holder.

B

Many such covers are designed, at least in the UK, to have a height or depth of 50mm or less, and the lock assembly of the present invention preferably has a maximum height or length of less than 50mm so as to fit within such cover depth, and not extend above its depth in use.

According to another aspect of the present invention, there is provided a key holder for use in a cover comprising one or more lock assemblies as defined herein.

Embodiments of the present invention will now be described by way of example only and with reference to the accompanying diagrammatic drawings in which: Figure 1 is a perspective view of a manhole cover, key holder and lock assembly according to one embodiment of the present invention; Figure 2 is an upper perspective view of the key holder and lock assembly of Figure 1 in a first locking position; Figure 3 is bottom view of the key holder and lock assembly of Figure 2; Figure 4 is a cross-sectional view along line BB of the key holder and lock assembly of Figure 3; Figure 5 is an upper perspective exploded view of the parts of the lock assembly of Figure 4; and Figures 6 and 7 are opposite perspective views of the shaft and key socket shown in Figure 5.

Referring to the drawings, Figure 1 shows a perspective view of a manhole cover 2.

Such manhole covers are well known in the art, and may be used in a streeli, in a road, on or off a pavement or other passageway, all generally intended for the passage of traffic thereacross, and generally intended to provide access thereunder usually for repair or the like thereunder. Such covers can be made of one or more of the group comprising; concrete, steel, other metals, composites or the like, generally intended to have sufficient robustness to withstand the pressure of traffic thereacross, whilst still being liftable by one or persons when access thereunder is required.

The manhole cover 2 in Figure 1 includes two key holders 4, generally having at least one slot 6, usually an elongate slot, able to accept the end of a lifting means such as a dog-legged lifting bar (not shown), whose free end is insertable and rotatable therein for lifting the manhole cover out of or into its position in a known manner, usually out of or into a surrounding frame (not shown) fixed within the level of the street, road, etc. The key holder 4 is generally formed by a shaped metal enclosure locatable within the manhole cover 2 during manufacture to provide space therewithin for the entry and rotation of the end of a suitable lifting means.

Next to each slot 6, and within each key holder 4, there is located a lock assembly 10 according to one embodiment of the present invention. Figure 1 shows the key cover 12 of the lock assembly 10 visible in use, having an aperture 16.

The depth of the cover 2, shown as height AA, is or is generally less than 50mm.

Figure 2 shows the key holder 4 outwith the manhole cover 2. The key holder 4 is generally formed of a folded and/or welded piece of metal having an open side' beyond which the distal end of a latch 24 can extend, and therefore extend into or under a latch plate (not shown) or similar, (which could be located within the frame of the cover 2, or otherwise be internally formed in a frame so as to provide space for accommodation of that part of the latch), and to thereby lock the cover 2 in its usual position over or otherwise protecting a hole or space thereunder in a manner know in the art.

Figure 2 shows the lock assembly 10 and lock housing 14 in the key holder 4. The height of the key holder 4, again shown as height AA is less than 50mm. In particular, this height requires the latch to be flush or flat along its lowermost edge or bottom, to achieve the compactness required for the lock assembly 10 to fit within the key holder 4, and the complete key holder 4 to fit within the cover 2 and be flush with its uppermost line or level or surface.

Figure 3 is a bottom view of the key holder 4 and lock assembly 10 as shown in Figure 2, including the extension of the latch 24 beyond the edge of the lock housing 4. Rotation of the latch 24, generally by a number of degrees) possibly up to 90 degrees) means that its distal end no longer extends beyond the edge of the key holder 4.

Figure 4 is a section BB through figure 3, showing in particular a cross-sectional view of the lock assembly 10. Figure 4 shows the lock assembly 10 comprising a lock housing 14 located in the key holder 4, generally by its secure fixing into a suitable aperture in the key holder 4, optionally based on a flange of the lock housing 14.

Within the lock housing 14 is the key cover 12 and a shaft 18) described in more detail in relation to figures 5 and 6, and moveable in the lock housing 14 between a first locking position as shown in figures 2 and 3, and a second open position (not shown)) generally based on rotation of the latch 24 once free of the lock housing 14.

Figure 4 also shows a biaser, being by way of example only a helical spring 26. In one action, the helical spring 26 biases an upper end of the shaft 18 away from a platform in the lock housing 14) and hence biases the attached latch 24 in its locking position in a lower section of the shaft 18 and in a slot or recess 13 in the shaft 18.

Figure 5 is a first perspective and exploded view of the parts of the Jock assembly 10, with a key socket 30.

Figure 5 shows the generally cylindrical or barrel-shaped lock housing 14, having a latch end with a first recess 13 as described hereinabove, and a second perpendicular recess 15, each recess 13, 15 able to take the width of the latch 24.

Between each recess 13, 15 could be an additional shoulder 17 to increase the barrier between the latch 24 moving between the recesses 13 and 15, and thus further preventing its accidental or unintentional movement between its open and closed positions.

Within the lock housing 14 is located the shaft 18, having an enlarged key-head 19 comprising a key-head portion 32 at the key end of the lock housing 14 as discussed in more detail hereinafter. The latch 24 is conjoined with the latch end of the shaft 18.

The helical spring 26 has a number of turns to fit around the longitudinal portion of the shaft 18, and a first end to fit into a complementary slot iSa in the key-head 19, and a second end to fit into a complementary slot 23 near the base of the lock housing 14.

Preferably, the helical spring 26 is a torsion spring. More preferably, it is able to keep a constant right hand pressure on the shaft 18 in use, and in particular on the key-head 19. The spring 26 may be pre-loaded or pre-tensioned, by the particular location of the slots iSa, 23 to fit its ends, and thus the position of the spring 26 during assembly of the lock assembly 10, such that force is required by the key socket 30 for any movement of the shaft 18 in the lock housing 14, as described in more detail hereinafter.

Figure 5 also shows the key cover 12 shaped to fit over the key-head 19 of the shaft 18, and to fit into the key end of the lock housing 14 to provide top of the lock assembly 10 in a final form ready for use.

The key cover 12 has an aperture 16 with a particular circumferential shape: in the example shown in Figure 5, the shape is an elongate slot with an enlarged circular central portion.

Figure 6 shows the shaft 18 from an opposite perspective, wherein the key-head portion 32 is more clearly shown as a recess within the key head 19, having a circumferential shape being generally the same as that of the aperture 16 in the key cover 12.

Figures 5 and 7 show the key socket 30 having a corresponding or complementary key-head shape 34 on one side or at one end thereof. Preferably, the key-head shape 34 is directly corresponding to the key-head portion 32, and slightly smaller than the aperture 16. At the other end or side of the key socket 30, there is a triangular head 36.

To construct the lock assembly 10, those parts shown in Figure 5 (other than the key socket 30) are provided and brought together. The assembled lock assembly 10 can then be located with and fixed to a key holder 4, which key holder 4 can then be added to a manhole cover 2 as shown in Figure 1, or the like.

The particular parts shown in Figure 5, other than the key socket 30, allows the forming of the lock assembly 10 that is less than 50mm in height or length, with the key cover 12 fitting within the housing 14, and the latch 24 fitting, whether in its open or closed position, within the other end of the housing 14.

Figures 2 and 3 show the lock assembly 10 having the latch 24 in a first locking position, i.e. wherein the latch 24 extends outwardly beyond the boundary of the key cover 4, and can therefore lock the key cover 4 against a suitable frame or the like.

When it is desired to open' the manhole cover 2, i.e. by its movement or removal from its normal location, the user first inserts the key-head shape 34 of a key socket 30, generally provided separately or kept: separate from the lock assembly 10, through the aperture 16 of the key cover 12.

Preferably, the circumferential shapes of the aperture 16 and the key-head portion 32 in the key-head 19 of the shaft 18 are in alignment, such that a single longitudinal movement of the key socket 30 is only required for the key-head shape 34 to pass through the aperture 16 and into the key-head portion 32. Force is then required on the key socket 30 in order to move the shaft 18 in the lock housing 14, and thereby move the latch 24 between its first locking position and second open position.

The force can be provided by a separate item or device (which could include a separately defined key') having a suitable complementary key-head portion to the triangular head 36 at the other end of the key socket 30. Thus, opening of the lock assembly 30 still requires the use of a particular further device to work the key socket 30, such that even accidental availability of the key socket 30 to a third party, such as being left with the manhole cover 2 after use, does still not lead to easy accessibility by an unauthorised user.

Force can be directed down through the key socket 30 to move the shaft 18 longitudinally against the biasing force of the helical spring 26, and move the latch 24 out of the first recess 13 and beyond the latch end of the lock housing 14.

Subsequent rotational movement of the key socket 30 provides rotational movement of the shaft 18, and rotational movement of the latch 24 towards its open position. Relaxation of the longitudinal force then allows the latch 24 to fit into its second recess 15 in its second open position.

However, rotation of the key socket 30 and shaft 18 now means that at least a portion of the aperture 16 does not overlap with at least a portion of the key-head portion 32 of the shaft 18, now that the shaft is in its second open position. As the key-head portion 32 is occupied by the key-head shape 34 of the key socket 30, at least a portion of the key-head shape 34 is now trapped between the key-head 19 and the underside of the key cover 12, negating its release or separation from the lock assembly 10 whilst the latch 24 is in its open position. For the example shown in the figures, the portions of the key-head shape now trapped are the lateral ends 38 of the elongate part of the key-head shape 34.

In this way, the key socket 30 is trapped or otherwise captive within the lock assembly 10 when the shaft is in its second open position) and when the lock assembly 10 is therefore regarded as being "open" or unlocked". Thus, the user has a visua' indicator, being the remainder of the key socket 30 left extending above the leve' of the ock assembly 10, to indicate that the lock assembly is "open", and that the manhole cover 2 is therefore accessible or openable.

In particu'ar, the biasing force 26 of the helicth spring 26 assists the trapping of the parts of the key-head shape 34 of the key socket 30 between the underside of the key cover 12 and the key-head 19.

Another problem in the art is the attempted removal of the manhole cover 2 from its closed position directly with conventional keys or the like used to open the conventional manh6le lock assemblies. Applying the force required to move the manhole cover 2 through any such conventional key often leads to bending or breakage of the key, the conventional locking mechanism or both, with attendant problems. The requirement of needing a separate device or item to turn the key socket 30 via the triangular head 36, prevents a user from using such a separate device to try and lift the manhole cover 2 from its generally closed position) instead of using a lifting bar or similar through the lifting slot 6.

Locking of the lock assembly 10 can be carried out in the opposite manner. That is, by use the required device acting on the triangular head 36 of the key socket 30, the key socket 30 is rotated in an opposite manner to that before) whilst a'so applying some longitudina' force so as to move the latch 24 out of its second recess 15, over the shoulder 17, and into its first recess 13. Once in its correct locking position, the alignment of the latch 24 and the shaft 18 with the aperture 16 in the key cover 12 allows the removal of the key socket 30 from the lock assembly 10. Removal of the key socket 30 is a clear indicator to the user that the lock assembly 10 is now in its first locking position, such that the manhole cover 2 must therefore now be locked as desired Various modifications and variations to the described embodiments of the invention will be apparent to those skilled in the art without departing from the scope of the invention as defined herein. Although the invention has been described in connection with specific preferred embodiments it should be understood that the invention as defined herein should not be unduly limited to such specific embodiments.

Claims

Claims 1. A lock assembly comprising: (a) a lock housing having a key end and a ktch end; (b) a shaft movealMe in the lock housing between a first locking position and second open position, the shaft having a key head comprising a key-head portion near the key end of the lock housing, and a latch end; (cJ a biaser to bias the shaft in its first locking position; (d) a ktch conjoined with the latch end of the shaft and moveable by the shaft between a first locking position and a second open position; and (e) a key cover at the key end of the ock housing and above the key head of the shaft, the key cover having an aperture for access to the key-head portion, and wherein at least a portion of the aperture does not overlap with at least a portion of the key-head portion of the shaft when the shaft is in its second open position.
2. A lock assembly as claimed in claim 1 wherein the lock housing has a first section for partially, wholly or substantially housing the shaft, and also for partially, wholly or substantially accommodating the biaser between part of the lock housing and the shaft.
3. A lock assembly as claimed in daim 1 or claim 2 wherein the lock housing has an outer wafl section and at kast one traverse section, the biaser being ocated between the traverse section and a head portion of the shaft
4. A lock assemlMy as daimed in any one of the preceding claims wherein the biaser is fixed at one end to the shaft, and fixed at the other end to the one end to lock housing.
5. A lock assembly as claimed in any one of the preceding claims wherein the biaser is a helical spring.
6. A lock assembly as claimed in any one of the preceding claims wherein the biaser is a torsion spring, and is preloaded or predisposed to bias the shaft to its first locking position.
7. A lock assembly as claimed in any one of the preceding claims wherein the biaser provides biasing against the shaft moving in at least a longitudinal direction along the lock housing.
8. A lock assembly as claimed in any one of the preceding claims wherein the biaser provides biasing against rotation of the shaft from the first locking position to the second open position.
9. A lock assembly as claimed in any one of the preceding claims wherein the biaser biases the shaft to its first locking position following any compression of the biaser.
10. A lock assembly as claimed in any one of the preceding claims wherein the lock housing includes a second section able to partially, wholly or substantially house the latch, at least in its first locking position.
11. A lock assembly as claimed in claim 10 wherein the latch is housed in the lock housing so as not to be moveable between its first and second positions without the latch being outside the lock housing.
12. A lock assembly as claimed in any one of the preceding claims wherein the latch is moveable between its first locking position and its second open position by longitudinal movement of the shaft through the lock housing and by rotation of the shaft about the lock housing, and vice versa.
13. A lock assembly as claimed in any one of the preceding claims wherein the shaft comprises a body having an enlarged head and a central column, the enlarged head including the key head, and including the key head portion.
14. A lock assemlMy as daimed in any one of the preceding claims wherein the key head portion is in the form of an elongate slot in the key head.
15. A lock assemlMy as daimed in any one of the preceding claims wherein the lock assemlMy of the present invention includes a key socket having a corresponding or complementary key-head shape to the key-head portion at one end thereof
16. A lock assemNy as daimed in any one of the preceding claims wherein the key cover is wholly or substantially at or near the key end of the lock housing, and optionally forms the top portion thereof being that portion which is visible to the user.
17. A lock assembly as claimed in any one of the preceding claims wherein the circumference of the aperture of the key cover is wholly or substantially in alignment with the circumference of the key head portion when the shaft is in its first locked position to provide direct longitudinal access to the key-head portion through the aperture.
18. A lock assemNy as daimed in any one of the preceding claims wherein the key or any key socket is not separaNe or recoveraNe from the lock assembly when the shaft is in its second open position, as a part of the key or key socket out of allgnment with the aperture, and is located between the key head of the shaft and the underside of the key cover, and is biased in that position by the biaser.
19. A lock assembly as claimed in any one of the preceding daims wherein removal of the key or any key socket is only possible when the shaft is in its first locking position.
20. A lock assembly as claimed in any one of the preceding claims wherein the biaser is biased against longitudinal movement and rotational movement of the shaft between the first locking position and the second open position.
21. A lock assembly as claimed in any one of the preceding claims wherein the lock assembly is locatable within the key holder of a cover.
22. A lock assembly as claimed in any one of the preceding claims being less than 50mm in length.
23. A lock assembly as claimed in any one of the preceding claims wherein the shaft is straight, and extends directly from its key head at one end to the conjunction with the latch at its other end, the latch has a flat bottom or flat lowermost edge, the latch extends transversely from a lowermost end of the shaft, and the key cover is within the dimensions of the lock housing.
24. A street or road cover comprising one or more lock assemblies as defined in one or more of claims 1 to 23.
25. A street or road cover as claimed in claim 24 wherein the cover includes one or more key holders, and the or each lock assembly is located within an associated key holder.
26. A street or road cover as claimed in either claim 24 or claim 25 being 50mm or less in depth.
27. A key holder for use in a street or road cover comprising one or more lock assemblies as defined in one or more of claims ito 23.
28. A Jock assembly substantially as hereindefined with reference to Figures 1-7.