GB2262119A - Lockable access cover - Google Patents

Abstract

An access cover (1) has locking means incorporating a key-operated lock (20) to secure the access cover in a frame (2). In order to prevent ingress of water and dirt into the lock a cover plate is provided movable between a closed configuration in which it covers the lock (20) and prevent access thereto and an open configuration in which access to the lock is available. The locking means preferably comprises a hinge (8), one leaf (10) of which is secured to the access cover and carries the key-operated lock and the other of which (9) constitutes the cover plate. <IMAGE>

Description

LOCKING OF ACCESS COVERS The present invention relates to security locking of access covers.

Access covers are used in a wide variety of applications, such as to cover holes in roads and pathways which allow access to drains, cable ducts or machinery rooms etc. Most commonly, an access cover is removed using a simple tool of a standard pattern which engages in a hole and provides a handle by which the access cover may be lifted.

In some situations there is a requirement to secure the access cover against unauthorised removal in order to prevent access to secure areas and/or dangerous machinery. (The standard key is an off-the-shelf item; it is not a security device.) The present invention provides, in a first aspect, an access cover comprising locking means adapted to releasably secure the cover within a frame, the locking means incorporating a key-operated lock having a keyhole presented towards an outside surface of the cover, and a cover plate movable between a closed configuration in which it covers the keyhole, preventing access thereto, and an open configuration in which access to the keyhole is available.

The cover plate is normally left in its closed configuration in order to shield the keyhole from dirt and weather.

Conveniently, the cover plate may be hinged, preferably such that it is flush with the outside surface of the access cover in its closed configuration and projects from the said surface in its open configuration.

The cover plate is preferably provided with a fastener to retain it in its closed configuration. The fastener is preferably a simple fastener which does not have a complex mechanism which could be damaged by exposure to weather; it need not be a high security device. The fastener is preferably operable with a simple tool which advantageously is not of a commonly-available type. A fastener such as this provides a measure of security against casual interference with the lock. However, security against more determined interference is provided by the key-operated lock.

The fastener of the last-preceding paragraph may be of a type, such as an Oddie fastener, which causes the cover plate to be urged away from its closed configuration when the fastener is released. This gives a clear indication that the fastener has not been secured so reducing the chance that the cover plate is accidentally or deliberately left un-secured.

The locking means may be constructed on a separate metal pocket component which is secured, e.g. by welding, to and inside surface of the access cover, an aperture being formed in the cover to allow access to the locking means from outside the cover.

The locking means may comprise a hinge having two leaves secured to the access cover (and preferably to the pocket of the last-preceding paragraph) one leaf of the hinge, fast with the access cover, carrying the key-operated lock, the other leaf, constituting the cover plate, being pivotable between a closed configuration in which it covers the key-operated lock and an open configuration in which access is available to the key-operated lock. The fastener preferably is operable to secure the hinge in its closed configuration.

From another aspect, the invention provides a locking means for an access cover in accordance with the first aspect of the invention.

An embodiment of the invention will now be described in detail, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a transverse cross-section of a locking device for an access cover embodying the invention; Figure 2 is a plan view of the locking device of Figure 1; Figures 3a and 3b show a pocket component of the locking device of Figures 1 and 2; Figures 4a and 4b show a hinge component of the locking device of Figures 1 and 2; Figure 5 shows a stud component of a fastener for use in the locking device in Figures 1 and 2; and Figure 6 shows a tool suitable for operation of the stud of Figure 5.

In the following description, it will be assumed that the access cover is mounted in a horizontal surface with the access cover uppermost, and removable upwards. The term "up" and "down", and associated terms, should be interpreted accordingly. However, it will be understood that an access cover embodying the invention may be used in any orientation.

With reference to Figure 1, an access cover 1 is arranged to be mounted in a frame 2. The frame 2 defines the boundaries of a clear opening through which access is required from time to time. The access cover 1, when in place, closes off the opening.

An aperture is provided through the access cover 1, close to an edge thereof, to provide access to the locking device, as will be described.

The locking device is built up on a metal pocket 3, which is welded on to the underside of the access cover 1 below the aperture. The pocket 3, which is shown in detail in Figures 3a and 3b, is rectangular in plan. It comprises a supporting flange 4, which is also rectangular in plan and which has a centrally-positioned rectangular aperture 5. An upstanding wall 6 projects from the edge portion of the flange 4 and extends around its periphery.

A stirrup 7 projects downwardly from one end portion of the pocket 3 away from the upstanding wall 6. The stirrup 7 is a short, U-shaped piece of metal channel and is attached to the pocket 3 by welding the free end of its legs to the lower surface of the flange 4. The channel which constitutes the stirrup 7 is aligned with the long axis of the pocket 3 and is flush with one of the shorter sides of the pocket 3. The purpose of the stirrup 7 is to protect the cylinder lock, which will be described below.

A butt hinge 8, which has upper and lower mutually pivotable leaves 9, 10, is fixed by its lower leaf 10 to the flange 4. A suitable hinge is shown in detail in Figures 4a and 4b. Each leaf 9, 10 has a flat, rectangular plate portion 9', 10', at one end of which is formed an interconnection portion 9", 10". Each interconnection portion 9", 10" comprises a loop through which a hinge pin 14 is passed to interconnect the leaves. The centres of the loops are arranged such that when the hinge 8 is in a closed configuration, with the plate portions 9', 10' of the leaves parallel, the plate portions 9', 10' are spaced apart from one another. Holes 11 are provided through the plate portion 10' of the fixed lower leaf 10 and corresponding holes 12 are provided in the flange, bolts 13 being passed through both sets of holes to secure the hinge in position. The holes 11 in the fixed lower leaf 10 are countersunk, the bolts 13 having correspondingly shaped heads, to provide the plate portion 10 of the lower leaf 10 with a generally flat upper surface.

Two further holes are provided in the plate portion 10' of the fixed lower leaf 10. A first hole 15 is square in shape and the second hole 16 is circular with two diametrically opposed chordal flats 17. A small circular hole 18 is provided in the upper leaf concentric with the first, square hole 15 in the lower leaf when the hinge 8 is in its closed configuration.

The second hole 16 is used to mount a cylinder lock 20. The lock 20 has an externally-threaded, generally-cylindrical barrel which is passed through the hole 16. The barrel has two diametrically opposed flats which engage with the flats 17 of the hole so as to prevent the lock 20 turning in the hole 17. At one end of the barrel, the lock 20 has a flange 21 in which, in its end face, a keyhole is provided. The diameter of the flange is larger than the hole 16 so that it cannot pass through the hole. The lock 20 is mounted by passing it through the hole so that the flange and keyhole project upwards, that is, towards the upper leaf 9. A nut 22 is then screwed onto the barrel from the lower side of the lower leaf 10 to secure the lock 20 in place.

An elongate locking bar 23 is attached by one of its end portions to; the lower part of the lock 20.

The locking bar 23 is rotatable, by a key inserted into the lock 20, in a plane generally parallel with the plate portion 10' of the fixed lower leaf 10. When the access cover 1 is in position in its frame 2, the key may be used to rotate the locking bar 23 such that its free end portion passes below a projecting locking formation 24 of the frame 2. The access cover 1 is thus secured in place in the frame 2. If the access cover 1 is to be removed then the key is used to rotate the locking bar 23 to a position in which it is clear of the locking formation 24.

In order to gain access to the lock 20 for operation, the upper leaf 9 of the hinge 8 must be in an open configuration, as shown in chain lines in Figure 1 and in solid lines in Figure 2. When the hinge is returned to its closed condition, with the leaves parallel (as shown in the main drawing of Figure 1) the plate portion 9' of the upper leaf 9 (constituting a cover plate for the lock 20) completely covers the flange 21 of the lock 20. In the closed configuration, the lock 20 is protected against ingress of water and dirt. Furthermore, as will now be described, a fastener is provided to secure the upper leaf 9 in its closed configuration in order to deter any casual attempt to interfere with the lock 20.

The fastener may be an Oddie fastener. Such a fastener as shown in Figures 1 and 2 has a clip 27 secured through the square hole 15 of the fixed lower leaf 10 and a stud 26 secured through the circular hole 18 in the upper leaf 9. The fastener is operated by rotation of the stud through 90 degrees between a locked orientation in which a projecting part of the stud 26 may be pushed into the clip whereupon it will be retained there, and an unlocked orientation in which the stud may be removed from the clip 27. A resilient washer 28 is placed around the stud 26 which is compressed between the stud and the clip when the stud is retained within the clip. This creates a rattle-free interengagement and causes the stud 26 to eject automatically from the clip 27 when turned to its unlocked orientation.

One end of the stud 26, on which is formed a head, projects from the upper surface of the upper leaf 9.

This head is accessible when the upper leaf 9 is in its closed condition. The head has formations which may be engaged by a tool in order to rotate the stud 26 between its locked and unlocked orientations. (The stud 26, when locked into the clip 27, is gripped by the washer 28 with sufficient friction to prevent it from being turned by hand.) The formations may be of any suitable type but are preferably of such a form that a person with a casual, mischievous interest in releasing the hinge 8 to gain access to the lock 2 would be unlikely to have a suitable tool. Thus, formations operable by an ordinary spanner or screwdriver should be avoided.

A suitable type of formation, illustrated in Figure 5, comprises two spaced holes 30 sunk into an otherwise flat head 31. A suitable tool for operation of this fastener is shown in Figure 6. It comprises a T-shaped handle 32 which has two circular pegs 33 projecting from the end of the leg of the T. These pegs 33 engage in the holes 30 to allow the stud 26 to be rotated. Such a tool may be easily manufactured but is not in widespread use. Clearly, this will not stop a more determined attempt to remove an access cover secured by the locking device of the present invention; that is the job of the lock 20.

Claims (11)

1. An access cover comprising locking means adapted to releasably secure the cover within a frame, the locking means incorporating a key-operated lock having a keyhole presented towards an outside surface of the cover, and a cover plate movable between a closed configuration in which it covers the keyhole, preventing access thereto, and an open configuration in which access to the keyhole is available.

2. An access cover according to Claim 1 in which the cover plate is hinged for movement between its open and its closed configurations.

3. An access cover according to Claim 1 or Claim 2 in which when the cover plate is in its closed configuration it is flush with the outside surface of the access cover.

4. An access cover according to any preceding claim in which the cover plate is provided with a fastener operable to retain it in its closed configuration and releasable to allow the cover plate to be moved from its closed to its open configuration.

5. An access cover according to Claim 4 in which the fastener when released urges the cover plate from its closed configuration towards its open configuration.

6. An access cover according to any preceding claim in which the locking means further comprises a hinge having first and second leaves, the first leaf being fast with the access cover and the second leaf being pivotable relative thereto, the second leaf constituting the cover plate.

7. An access cover according to Claim 6 in which the key-operated lock is mounted on the first leaf.

8. An access cover according to Claim 6 or Claim 7 which further comprises a metal pocket secured to a lower surface of the cover plate the first leaf of the hinge being mounted on the pocket, and there being provided an aperture in the cover plate through which the second leaf projects when in its open configuration.

9. A locking means for releasably securing an access cover into a frame comprising a key-operated lock having a keyhole and a cover plate movable between a closed configuration in which it covers the keyhole preventing access thereto, and an open condition in which access to the keyhole is available.

10. An access cover substantially as described with reference to the accompanying drawings.

11. A locking means for an access cover substantially as described with reference to the accompanying drawings.