FIELD OF THE INVENTION

This invention relates to a locking device and in particular adapted for use with an electrical switchboard door. BACKGROUND TO THE INVENTION

Switchboard enclosures typically comprise a box or cabinet which can be mounted or fixed to a wall and house electrical switchgear attached to a mounting base and protected by a faceplate or escutcheon. The switchboard enclosures or cabinets are usually of a steel construction and include a door that is sealed so as to protect the electrical equipment from dust and water ingress and is particularly useful in environments such as the mining industry, where safeguarding electronics from foreign material is imperative.

The door includes a handle or lock so that the switchboard can be accessed when needed, and the door kept secured at other times. In order to protect the switchboard and equipment inside, it is imperative that the door is shut securely and does not swing open when unattended, and also that the switchboard is not accessed by unauthorized persons. The door therefore often includes a securing means so that the door can be securely locked to the cabinet.

The door handle may contain a lock mechanism that is secured with a key, however this lock and key is manufactured with the cabinet and so the user does not have the ability to use another locking means such as a padlock or lockout tag. If the key should be lost, an exact replacement must be ordered from the manufacturer of the cabinet. Furthermore such a lockable handle is quite expensive and some key locks, while they secure the door, still allow free movement of the handle which may be vulnerable to tampering or damage.

In order to provide security for such door handles it has been known to attach a locking point to the door which is so configured to capture the end of the door handle and lock it in place using a padlock. This however requires that the locking point is attached to the door by drilling a hole therethrough. This then compromises the integrity of the switchboard and increases the chance that foreign material may find its way into the enclosure.

Internal locking mechanisms without a handle are known and are openable by a switchboard tools however they are also vulnerable to tampering.

The object of this invention is to provide a locking device that alleviates the above problems, or at least provides the public with a useful alternative. Whilst the description discusses an electrical switchboard door it is to be understood that it may equally well apply to any door that defines an enclosure;.

SUMMARY OF THE INVENTION

Therefore in one form of the invention there is proposed a locking device for use with a door for an enclosure the locking device comprising:

a first member including a cylindrical skirt defining a first bore of a first diameter extending to a first flange, extending from which is a male member defining a second bore of a smaller diameter extending from the first flange to a second flange, the male member adapted to extend through the door and be secured thereto;

a second member including a first cylinder correspondingly shaped to and adapted to extend into the first bore, a second cylinder correspondingly shaped to and adapted to extend into the second bore and a projection adapted to extend through the male member into the enclosure, the projection including a latch adapted to engage the enclosure to latch the door in a closed position;

the cylindrical skirt of the first member and the first cylinder including coaxial opposing apertures that when rotationally aligned allow the passage of a locking member there through.

The male member is secured to the door using well known techniques that would be obvious to the reader. By locking the first and second members together the second member is prevented from rotational movement and thus the latch is locked in the latch position. Preferably the top of the male member includes a cut-out adapted to limit the rotational movement of the latch. Such movement is typically limited to a 90 degree rotation.

Preferably the locking member is a padlock.

In preference extending from the first cylinder is a handle to facilitate the rotation of the second member.

In preference located in the first bore is a key activated means to rotate the latch.

Alternatively such an activation means may be located deep within the first bore so that the locking means, such as a padlock, does not effectively prevent the rotation of the second member but rather access to it.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate various implementations of the invention and, together with the description, serve to explain the advantages and principles of the invention. In the drawings:

Figure 1A is a perspective view of a locking mechanism including a collar and male member;

Figure IB is a perspective view of the collet of the locking device;

Figure 2 is a perspective view of a handle without the locking device;

Figure 3 is a perspective view of the locking device attached to the handle;

Figure 4 is a perspective view of the locking device attached to the handle and engaged by a padlock;

Figure 5A is a plan view of the locking device attached to a padlock and existing locking mechanism comprising an alternate embodiment of the invention;

Figure 5B is a perspective view of the alternate embodiment including the padlock and locking device; Figure 5C is a perspective view of the alternate embodiment attached to the cabinet door;

Figure 6A is a plan view of the locking device attached to a padlock and existing locking mechanism comprising a further alternate embodiment;

Figure 6B is a perspective view of the further alternate embodiment including the padlock and the locking device; and

Figure 6C is a perspective view of the further alternate embodiment attached to the cabinet door.

LIST OF COMPONENTS

20 Locking device

22 Locking device male member

23 Collet flange

24 Collet

25 Collet opening

26 Collet apertures

27 Male member opening

28 Handle

29 Male member lip

30 Handle lever

32 Handle neck

34 Handle neck column

35 O-ring

36 Handle neck base

37 Handle base flange

38 Handle neck tip 39 Handle column flange

40 Handle apertures

42 Padlock

44 Padlock shackle

48 Cabinet door

50 Cabinet door external lock

52 Cabinet door internal lock

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

The following detailed description of the invention refers to the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings and the following description to refer to the same and like parts.

Dimensions of certain parts shown in the drawings may have been modified and/or exaggerated for the purposes of clarity or illustration.

Turning now to the drawings in Figure 1A there is illustrated a locking device 20 consisting of a male member 22 and a cylindrical skirt or collet 24. The collet forms the lower piece of the locking device containing a lower opening 25, with the upper piece of the locking device formed by a male member 22 containing an upper piece of a narrower diameter and an upper opening 27. A flange or ridge 23 is therefore formed by the narrower male member 22 on top of the wider collet 24.

The male member 22 has a cylindrical interior shape and an outer square shape adapted for insertion through a door aperture having a similar square shape. The tip of the member also contains a raised lip 29 formed 270 degrees around the upper opening 27, leaving a 90 degree indent around the opening. When connected to the door handle, this lip configuration allows the handle to be rotated no further than 90 degrees, as the handle is stopped by abutting against the raised lip 29.

The locking device is hollow and thus designed to fit over the neck of a door handle on a switchboard enclosure, although it is to be understood that it can be attached to any handle in order to provide a secure locking means. The locking device 20 also contains two apertures 26 on each side of the collet 24 in line with one another and adapted for the insertion of a locking means such as a padlock, rod or lockout tag.

Another view of the locking device 20 is illustrated in Figure IB, where both of the collet apertures 26 and the cylindrical interior of the male member 22 can be seen.

There is also illustrated in Figure IB the three planes of the locking device 20, comprising of the lower plane defined by the collet opening 25, the middle plane defined by the collet flange 23 and the upper plane defined by the male member opening 27. These three planes are each designed to complement and fit over the planes of the handle neck 32.

In Figure 2 there is illustrated a door handle 28 adapted for use with the locking device consisting of a lever 30 for use in turning the handle and a neck 32 which is of a similar shape as the locking device 20, including a cylindrical base 36, a cylindrical column 34, an lip and O-ring 35 and a square-shaped tip 38. The column 34 is of a smaller diameter than the base 36 and the tip 38 is of a smaller diameter than the lip and O-ring 35. Thus a base flange 37 is formed between the base 36 and the column 34, and a column flange 39 is formed between the column 34 and the tip 38. An O-ring 35 can also be applied to and rest on the column flange 39.

The neck base 36 also includes two apertures 40 on each side of the base in line with one another and creating a hollow passage through the neck 32 for the insertion of a locking means.

Figure 3 illustrates the locking device 20 attached to the handle 28. The locking device 20 is fitted over the handle neck 32 to align the first plane, with the collet flange 23 resting on the base flange 37, the O-ring 35 within the male member 22 and the neck tip 38 protruding through the member opening 27. The O- ring 35 can also be adapted to allow for the insertion of a nut and washer in order to connect the handle latch and lock tongue 46. The collet apertures 26 and the handle apertures 40 therefore line up with one another. When aligned, they form a passage through which a locking means can be inserted, clamping the handle 28 and the locking device 20 together.

The member 22 can then be attached to a cabinet door 48 by insertion through an aperture and thus securing the locking device 20 and handle 28 to the door. A lock tongue can therefore be attached to the male member through a bolt, washer and spindle (not shown), the bolt pulling the tongue down the square section of the spindle until it bottoms out, with the tongue mating against the end of the male member 22, pulling the spindle in. The washer maintains tension between the handle and the male member 22, while the O-ring creates a seal against moisture.

When the handle 28 is horizontal, the lock tongue is the closed position, held between the inside of the cabinet door and wall and securing the door. When the handle lever 30 is turned, the tongue is also rotated so that it no longer abuts against the inside of the cabinet wall, and the door is able to be opened.

It is to be understood that while this is the preferred embodiment on the invention, the locking device can be attached to the door with any of the known methods and used in conjunction with any known handle devices.

While the locking device 20 is firmly fitted over the handle neck 32, it is not tight enough a fit so to restrict movement of the handle 28, which can be turned as normal with the locking device 20 remaining in the same position.

Thus when the handle lever 30 is turned by the user into the open position, the handle apertures 40 and collet apertures 26 do not align, and therefore the handle 28 cannot be locked when the door is open. When the door is closed and the handle is in the closed position, the handle apertures and collet apertures align and the locking means can be inserted through the passage. This prevents any rotation of the handle and so provides a secure locking means.

Figure 4 illustrates the locking device 20 attached to the handle 28 and engaged with a padlock 42, with the padlock shackle 44 is inserted through the collet apertures 26, handle apertures 40 and neck base 36. While use of a padlock 42 to engage with the device 20 and handle 28 is a preferred embodiment of the invention, it is to be understood that any rod or device may be inserted through the apertures in order to secure the handle 28 and lock the door.

A further embodiment of the invention is the adaptation of the locking device to a handle within the cabinet door 48 and therefore used with existing lock inserts. Many cabinets are produced with a locking mechanism that requires the use of a tool or key to open. They are relatively flush against the cabinet door, incorporated into the door itself or otherwise protrude outwardly from the door. They are not large or sturdy enough to accommodate a padlock, nor do they have an external handle which the locking device can be fixed to.

The present invention can therefore also be adapted for use with such doors, whereby the male member 22 engages with the existing lock and the padlock 42 is engaged through the collet apertures 26 to prevent access to the lock. Alternatively, the male member 22 is machined to take the existing style of the lock to

accommodate the tool or key.

Figures 5A and 5B illustrate the locking device 20 attached to the padlock 42.

This version of the embodiment is adapted to a lock 50 which extends outwardly from the cabinet door 46. The locking device 20 shrouds this lock 50 and the padlock shackle 44 engages the device through the collet apertures 26 and corresponding apertures (not shown) on the lock 50. The lock 50, locking device 20 and padlock 42 are attached to the cabinet door 48 as illustrated in Figure 5C through an aperture punched into the door plate. The male member 22 of the locking device 20 would be inserted through the aperture, the collet flange resting flush against the cabinet door 48 and the collet 24 extending outwardly therefrom.

The lock 50 may incorporate a spindle, bolt and washer in order to attach a lock longue. When the tool or key is inserted into the lock 50 and turned it also causes the tongue to rotate and allows the door to be opened. The locking device 20 remains secured to the cabinet door, allowing the lock 50 to be turned within it and misaligning the apertures, so that the padlock 42 cannot be attached to the lock while the door is open. When the door is closed and relocked, the padlock 42 can be inserted through the aligned apertures. The tool or key can therefore not be inserted into the lock 50 without removing the padlock 42.

The second further embodiment is adapted to a lock 52 which is incorporated into the door 46. Illustrated in Figures 6 A and 6B is the locking device engaged with the padlock 42. The locking device 20 is attached to the door 46, the collet opening 25 allowing access to the lock 52 when the padlock is removed. The door can then be unlocked by the tool or key for access to the cabinet. When locked, the padlock shackle 44 can be engaged with the collet apertures 26 and block access to the internal lock 52. The locking device 20, internal lock 52 and padlock 42 attached to the cabinet door 48 are illustrated in Figure 6C.

An alternate way to describe the invention is to define a locking device, for use with a door for an enclosure that includes a first member including a cylindrical skirt defining a first bore of a first diameter extending to a first flange, extending from which is a male member defining a second bore of a smaller diameter extending from the first flange to a second flange, the male member adapted to extend through the door and be secured thereto. A second member includes a first cylinder correspondingly shaped to and adapted to extend into the first bore, a second cylinder correspondingly shaped to and adapted to extend into the second bore and a projection adapted to extend through the male member into the enclosure, the projection including a latch adapted to engage the enclosure to latch the door in a closed position. The cylindrical skirt of the first member and the first cylinder include co-axial opposing apertures that when rotationally aligned allow the passage of a locking member there through.

Further advantages and improvements may very well be made to the present invention without deviating from its scope. Although the invention has been shown and described in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope and spirit of the invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices and apparatus. Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of the common general knowledge in this field.

In the summary of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprising" is used in the sense of "including", i.e. the features specified may be associated with further features in various embodiments of the invention.