GB2468951A

GB2468951A - Lock assembly

Info

Publication number: GB2468951A
Application number: GB1004526A
Authority: GB
Inventors: Anthony Molloy
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-03-27
Filing date: 2010-03-18
Publication date: 2010-09-29
Anticipated expiration: 2030-03-18
Also published as: GB201004526D0; GB2468951B; GB0905248D0

Abstract

A lock assembly 10 comprising: a housing 12; a bolt 14 moveable in the housing between a first locking position (fig.2) and second open position (fig.3), the bolt having an exposed end having a non-circular key head and an opposite concealed end; a bias means, such as a spring 26, to bias the bolt in its first locking position; and a latch 24 conjoined with the concealed end of the bolt and moveable by the bolt between a first locking position and a second open position. The bias means may be located between the bolt head and a transverse section 22 of housing. Preferably the latch bolt is mounted for rotational and axial movement within the housing; a second section of housing depending from the transverse section preventing rotation of the bolt from the locked position until the bolt is axially moved to extend the latch from the housing to enable rotational movement. The non-circular bolt head may be oval or elliptical. The lock assembly may form part of a keyholder (4, fig.1) having an aperture to accept a lifting tool, the lock assembly being installed in a manhole cover (2, fig.1). Also claimed is a keyholder (4, fig.1).

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 under street, under road, under pavement or the like, access.

In such covers, there are usually one or more key holders, often one at each end or each side, intended for the insertion of "keys" designed to lift the cover from its road-or street-aligned position to gain access thereunder.

Typically, the key holders are locked, either directly or indirectly, to prevent unauthorised access, and particularly to prevent vandalism, usually by adventurous youngsters. However, such people also seek to undo simple 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.

It is an object of the present invention to provide a simple 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 housing; (b) a bolt moveable in the housing between a first locking position and second open position, the bolt having an exposed end having a non-circular key head and an opposite concealed end; (c) a biaser to bias the bolt in its first locking position; and (d) a latch conjoined with the concealed end of the bolt and moveable by the bolt between a first locking position and a second open position.

By having a non-circular key head, the bolt, being biased in its locking position, is difficult to turn without the correct key having the corresponding non-circular shape, making it difficult in turn to open the lock assembly and so any conjoined cover, etc. The simple mechanism of this lock assembly can also easily be housed in the spacing provided by or for conventional key holders in conventional covers.

The 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 housing has a first section suitable for partially, wholly or substantially housing the bolt, and also for partially, wholly or substantially accommodating the biaser between part of the housing and the bolt.

In one embodiment of the present invention, the 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 bolt having the exposed end.

In another embodiment of the present invention, the housing includes a second section able to partially, wholly or substantially house the latch, at least in its first locking position. Preferably, the latch is housed in the housing so as not to be moveable to its second open position without the latch being outside the housing. That is, the housing is able to constrain or confine the latch and prevent its movement when the latch is in its first locking position.

In another embodiment of the present invention, the latch is moveable between its first locking position and its second open position by movement of the bolt through the housing and/or by rotation of the bolt about the housing.

The bolt comprises an exposed end having a non-circular key head. The key head may have any non-circular shape radially, longitudinally or both.

This includes having a regular or non-regular circumferential shape, and preferably includes at least a circumferential (or cross-sectional) shape being oval, elliptical, polygonal, etc. For example, being generally circular but with a non-constant radius from one or more central points.

Preferably, the key head should be smooth in at least 2 or 3 dimensions, providing no defined edges, (which could be turned by a sharp tool or object not being the correct corresponding key). 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.

Preferably, the key head has a shape which is not obviously a distinctive or obviously different key head shape (such as a regular square), to reduce attention to its existence as the key head.

The non-circular nature of the key head may extend outwardly or inwardly relative to the remainder of the bolt. That is, the key head may have a convex or concave shaped when viewed from above or downwardly along the bolt.

The bolt is moveable between its first and second positions using a key 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 body, or extend outwardly from a key body, depending up on the arrangement of the key head on the bolt.

In one embodiment, the exposed end of the bolt is the non-circular key head, and the key head extends outwardly from the remainder of the bolt.

Preferably, the bolt comprises a body having an enlarged head and a central shaft, the enlarged head accommodating the non-circular key head, preferably in a recessed portion thereof. Also preferably, the key head extends outwardly, and top of the exposed end of the bolt is wholly or substantially planer or otherwise aligned with the top of the housing when the bolt is in its first locking 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.

Preferably, the biaser biases the bolt against movement from its first locking position.

In another embodiment of the present invention, at least the exposed end of the bolt is wholly or substantially accommodated in the first section of the housing in its first locking position. The bolt may wholly or substantially extends along the length of the housing, and along the longitudinal axis of the housing.

The bolt may be moveable in said first section of the housing along the longitudinal axis of the housing, and/or move in a rotatable manner about the longitudinal axis of the housing, preferably both. More preferably, the bolt is rotatable within the housing and moveable along the longitudinal axis of the housing against the biasing force of the biaser to move from its first locking position to its second open position. Movement of the bolt in at least one or possibly both directions is preferably only possible by action of a corresponding key. Indeed, the present invention extends to a lock assembly having a bolt as described herein and moveable in a first longitudinal direction in a housing and in a second rotatable direction, against the biasing force of a biaser.

The lock assembly of the present invention is preferably arranged such that one end of the latch is locatable under or against a suitable, and usually permanent, corresponding 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.

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 a cross-sectional view of a lock assembly according to the present invention in a first locking position; Figure 3 is a cross-sectional view of the lock assembly of Figure 2 in a second open position; Figures 4a and 4b are part cross-sectional and plan views respectively of a lock assembly in a first locking position and a latch plate; Figures 5a and 5b are part cross-sectional and plan views respectively of the lock assembly in its open position and the latch plate of Figures 4a and 4b; and Figures 6a and 6b are side and top views of a bolt useable in the lock assembly of the present invention.

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 street, 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 top of the housing (12) of the lock assembly (10), and the exposed end of a bolt of the lock assembly (10) having a non-circular key head (16).

A bolt (14) for the lock assembly (10) is shown in more detail in Figures 6a and 6b, having an enlarged head portion (18) and a shaft (20). Figure 6a shows the non-circular key head (16), being radially or circumferentially oval or elliptical in shape. In this way, rotation of the bolt (14) within the housing (12) is not possible without use of a particular key having a recess exactly matching the shape of the key head (16). A key having a circular recess would not fit perfectly on and around the complete circumference of the key head (16), and would not therefore provide sufficient grip of enough sides of the key head (16) to allow its rotation, especially when having to act against the biasing force discussed hereinafter.

Figure 2 shows in cross-section the bolt (14) within the housing (12). The bolt (14) extends along the longitudinal access of the housing (12), and the top of its exposed end (21) is in line with the top of the housing (12).

The housing (12) includes a transverse section (22) through which the elongate shaft (20) of the bolt (14) extends towards an attached latch (24).

Part of the latch (24) is located within a second section (28) of the housing (12), and part extends beyond the housing (12). That part of the latch (24) within the housing (12) is confined therein to prevent rotational movement of the latch (24).

Located between one face of the transverse section (22) and the enlarged head (18) of the bolt (14) is a biaser, being byway of example only a helical spring (26). The helical spring (26) biases the bolt (14) and hence the attached latch (24) in their first locking positions as shown in Figure 2.

Figure 3 shows both the bolt (14) and the latch (24) in their second open positions following opening of the lock assembly by means of a key (not shown). The key, having a suitable corresponding recess to the shape of the key head (16) in the bolt (14), is able to be used to force movement of the bolt longitudinally along the housing (12) against the biasing force of the helical spring to separate the latch (24) from the second section (28) of the housing (12). Rotation of the bolt (16) within the housing (12) by the key, still against the biasing force of the helical spring (26), is now also possible by the key because of the matching of the non-circular recess in the key holder and the non-circular key head (16) in the bolt (14). Rotation of the bolt (14) provides for rotation of the latch (24) now outside the housing (12).

Figure 4a and 4b show the location of the lock assembly (10) in its first locking position shown in Figure 2 with at least that part of the latch (24) not within the housing (12) extending beneath a latch plate (30). The latch plate (30) could be located within the frame of the cover (2), or otherwise be internally formed in the frame so as to provide space for the accommodation of that part of the latch. Figure 4b shows the lock assembly (10) in its first locking position wherein the latch (24), having part of it being located under the latch plate (30), is not moveable in the direction of arrow A, and is therefore able to lock the conjoined key holder (4) and cover (2) within its frame, and prevent (usually vertical) movement of the cover (2) out of and away from the frame.

Figures 5a and 5b show the arrangement of the lock assembly (10) of Figure 3 in its second open position, wherein the latch (24) has been completely separated from the housing (12) by action of a key to create downward movement of the bolt (14), followed by rotation by 90° or so, such that that portion of the latch (24) previously under the latch plate (30) is now free or not aligned with the latch plate (30), such that movement of the lock assembly (10) and the conjoined cover in the direction of line A is now possible. Such movement would generally be vertical movement of the cover out of its frame.

Reverse action of the key in association with the key head (16) would allow re-alignment of the part of the latch (24) conjoined with the bolt (14) with the second recess section (28) of the housing (12), following which the biasing force of the helical spring (26) would move the bolt (14) back into its first locking position as shown in Figure 2, and thus the latch (24) also into its first locking position as shown in Figures 4a and 4b.

The present invention provides a simple lock assembly able to be conveniently located within the space of conventional key holders used in conventional covers. The non-circular key head provides a tamperproof head on the locking bolt, which requires a special key to open it. Both longitudinal and rotational movement of the key (on the bolt and hence to the latch) are required to open the lock assembly, both of which would generally not be possible by implements other than the required corresponding key. With the key head being in a bolt biased towards its locking position, this further increases the tamperproof nature of the present invention by requiring a constant pressure on the bolt by the key during its rotational movement.

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 housing; (b) a bolt moveable in the housing between a first locking position and second open position, the bolt having an exposed end having a non-circular key head and an opposite concealed end; (c) a biaser to bias the bolt in its first locking position; and (d) a latch conjoined with the concealed end of the bolt and moveable by the bolt between a first locking position and a second open position.
2. A lock assembly as claimed in claim 1 wherein the housing has a first section for partially, wholly or substantially housing the bolt, and for partially, wholly or substantially accommodating the biaser between part of the housing and the bolt.
3. A lock assembly as claimed in claim 2 wherein at least the exposed end of the bolt is wholly or substantially accommodated in the first section of the housing in its first locking position.
4. A lock assembly as claimed in any one of the preceding claims wherein the 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 bolt having the exposed end.
5. A lock assembly as claimed in any one of the preceding claims wherein the housing includes a second section able to partially, wholly or substantially house the latch in its first locking position.
6. A lock assembly as claimed in any one of the preceding claims wherein the latch is housed in the housing so as not to be moveable to its second open position without the latch being outside the housing.
7. 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 movement of the bolt through the housing and/or by rotation of the bolt about the housing.
8. A lock assembly as claimed in any one of the preceding claims wherein the key head has a circumferential shape with a non-constant radius from one or more central points.
9. A lock assembly as claimed in claim 8 wherein the key head has an oval or elliptical circumferential shape.
10. A lock assembly as claimed in any one of the preceding claims wherein the key head extends outwardly relative to the remainder of the bolt.
11. A lock assembly as claimed in claim 10 wherein the exposed end of the bolt is the non-circular key head.
12. A lock assembly as claimed in any one of claims ito 10 wherein the bolt comprises a body having an enlarged head and a central shaft, the enlarged head accommodating the non-circular key head, preferably in a recessed portion thereof.
13. A lock assembly as claimed in any one of the preceding claims wherein the key head extends outwardly, and top of the exposed end of the bolt is wholly or substantially planer with the top of the housing when the bolt is in its first locking position.
14. A lock assembly as claimed in any one of the preceding claims wherein the biaser biases the bolt against movement from its first locking position.
15. A lock assembly as claimed in any one of the preceding claims wherein the bolt wholly or substantially extends along the length of the housing, and along a longitudinal axis of the housing.
16. A lock assembly as claimed in any one of the preceding claims wherein the bolt is moveable along a longitudinal axis of the housing, and/or move in a rotatable manner about a longitudinal axis of the housing, preferably both.
17. A lock assembly as claimed in claim 16 wherein the bolt is rotatable within the housing and moveable along the longitudinal axis of the housing against the biasing force of the biaser to move from its first locking position to its second open position.
18. A lock assembly as claimed in any one of the preceding claims wherein movement of the bolt is by action of a corresponding key.
19. A lock assembly as claimed in any one of the preceding claims wherein one end of the latch is locatable under or against a latch plate located in, on or otherwise about, a frame or frame assembly surrounding the lock assembly.
20. A lock assembly as claimed in claim 19 wherein the frame assembly is a frame for a cover such as a manhole cover.
21. A cover, such as a street or road cover, comprising one or more lock assembles as defined in any one of claims 1 to 20.
22. A cover as claimed in claim 21 being a manhole cover or a telephone exchange cover.
23. A cover as claimed in claim 21 or claim 22 including one or more key holders, and wherein the or each lock assembly is located within a key holder.
24. A key holder for use in a cover comprising one or more lock assemblies as defined in any one of claims I to 22.