WO2002042588A1

WO2002042588A1 - A locking mechanism

Info

Publication number: WO2002042588A1
Application number: PCT/IB2001/002207
Authority: WO
Inventors: Bryan Michael Risi
Original assignee: Bryan Michael Risi
Priority date: 2000-11-22
Filing date: 2001-11-22
Publication date: 2002-05-30
Also published as: AU2002223937A1

Abstract

The invention relates to a locking mechanism (10) for locking a closure member (12) to a support structure (14). The locking mechanism (10) includes an elongated shank (20) having a key-engaging end portion (34) which has a periphery that is non-circular in outline when viewed in end view; a security member (38) which is connected end-to-end with the shank (20) at the key-engaging end of the shank (20), the end-to-end connection being such that the security member (38) is freely rotatable about an axis of rotation (26) which extends longitudinally relative to the shank (20); and a housing member (16) which defines an opening (18) through which the shank (20) passes, the shank (20) being angularly displaceable about a longitudinal axis. The housing member (16) is mountable on the closure member (12) such that the shank (20) is angularly displaceable to move it between a locking condition in which the locking mechanism (10) locks the closure member (12) to the support structure (14), and an unlocked condition in which the locking mechanism (10) is unlocked, so that the closure member (12) is displaceable relative to the support structure (14).

Description

A LOCKING MECHANISM

This invention relates to a locking mechanism. In particular, it relates to a locking mechanism for locking a closure member to a support structure. The invention extends to a closure member incorporating the locking mechanism, to a closure installation incorporating the locking mechanism, and to a kit for locking a closure member to a support structure defining an opening.

According to a first aspect of the invention, there is provided a locking mechanism for locking a closure member to a support structure, which locking mechanism includes: an elongated shank having a key-engaging end portion which has a periphery that is non-circular in outline when viewed in end view; a security member which is connected end-to-end with the shank at the key- engaging end of the shank, the end-to-end connection being such that the security member is freely rotatable about an axis of rotation which extends longitudinally relative to the shank; and a housing member which defines an opening through which the shank passes, the shank being angularly displaceable about a longitudinal axis, the housing member being mountable on the closure member such that the shank is angularly displaceable to move it between a locking condition in which the locking mechanism locks the closure member to the support structure, and an

OONFWMAΠON COPY unlocked condition in which the locking mechanism is unlocked, so that the closure member is displaceable relative to the support structure.

In a preferred embodiment of the invention, the housing member defines a cavity which has a longitudinally outwardly opening key-receiving mouth,

the cavity being bordered by a peripheral wall which extends about the key- engaging end portion of the shank such that an annular space is defined between the periphery of the key-engaging end portion of the shank and the peripheral wall

of the cavity.

The security member may comprise a cover portion which has a periphery that, when viewed in^'end view, has a non-circular outline of the same shape as the outline of the key-engaging end portion of the shank, when viewed in end view, the outline of the periphery of the security member being no smaller than that of the key-engaging end portion of the shank. Advantageously, the

peripheral outline of said cover portion is larger than the peripheral outline of the key-engaging end portion of the shank.

In one embodiment of the invention, the security member comprises

a boss, the boss and the cover portion being freely rotatable relative to each other and relative to the shank about a common axis of rotation, the cover portion being located between the key-engaging end portion of the shank and the boss. Instead, the security member may comprise a boss which is integrally

formed with the cover portion, the boss projecting in a longitudinal direction from the cover portion, and the cover portion being located between the key-engaging

end portion of the shank and the boss.

The key-engaging end portion of the shank may be right-circular-

cylindrical, having a plurality of circumferentially spaced axially extending

formations on its cylindrically curved outer surface. Typically, the formations on the key-engaging end portion are axially extending circumferentially spaced flutes.

The cover portion may be disc-shaped, having a plurality of

circumferentially spaced axially extending formations on its circumferentially extending radially outwardly facing surface, the formations on the cover portion corresponding in circumferential spacing to that of the formations of the key- engaging end portion of the shank.

In particular embodiment of the invention, the locking mechanism includes a latch operatively connected to the shank, the latch being pivotally displaceable in response to angular displacement of the shank between a locked position corresponding to the locking condition of the shank and an unlocked position corresponding to the unlocked condition of the shank, the latch being

biassed towards its locked position. The locking mechanism may include a spring which exerts a torque on the shank to provide the bias of the latch towards its locked position.

75

Instead, an end of the shank opposite the key-engaging end may be

provided with a screw-thread for engagement with a complementary screw-thread forming part of the support structure, thereby to lock the closure member to the

support structure.

80

Instead, the shank, where it passes through the opening in the housing member, may have an external screw-thread which co-operates with a

complementary internal screw-thread in the opening, so that rotation of the shank causes axial displacement of the shank through the opening.

85

Advantageously, the locking mechanism has a plug member closing

a mouth of the housing member, the plug member being removably connectable to the housing member by rotation of the plug member about an axis aligned longitudinally with the shank, the plug member having a key-engaging protuberance so protruding from an outer end face of the plug member, the protuberance having a

non-circular peripheral outline when viewed in end view. The peripheral outline of the protuberance on the plug member may correspond in shape and in dimensions

to the peripheral outline of the key-engaging end portion of the shank when viewed in end view. Typically, the plug member is screw-threadedly engaged with the

95 housing member at or adjacent a mouth leading into the housing member. Instead, the locking mechanism may include a plug member closing a

mouth of the housing member, the plug member incorporating a lock which

100 unlockably locks the plug member in the mouth. This lock will typically have a bolt

movable by a key, or will be a combination lock having a bolt, the bolt engaging a groove or recess therefor in the housing member.

According to a second aspect of the invention, there is provided a 105 closure member which includes a locking mechanism as described above.

According to a third aspect of the invention, there is provided a closure installation which includes:

a support structure which defines an opening; no a closure member which is mounted on the support structure, being

displaceable between an open position, in which the opening is exposed, and a

closed position in which the closure member closes the opening; and

a locking mechanism as described above for unlockably locking the closure member in its closed position, the locking mechanism being mounted via its housing us member on the closure member.

According to a fourth aspect of the invention, there is provided a kit for locking a closure member to a support structure defining an opening, the kit including: 120 a locking mechanism as described above; and a key for applying torque to the shank of the locking mechanism, the key

defining, at its one end, a socket bordered by a peripherally extending socket wall which has an internal outline, when viewed in cross section, which is

125 complementary to the outline of the key-engaging end portion of the shank, when viewed in end view, the socket wall being engageable with the key-engaging end

portion of the shank, so that the key-engaging end portion mates with the socket, allowing torque to be applied to the shank.

130 The invention will now be further described, by way of example, with reference to the accompanying diagrammatic drawings, in which:

Figure 1 shows a schematic part sectional plan view of a locking mechanism in accordance with the invention;

Figure 2 shows a schematic end elevation of the locking mechanism of

135 Figure 1 ;

Figure 3 shows a view corresponding to Figure 1 , with a plug forming part

of the locking mechanism removed, and a key in engagement with the locking mechanism;

Figure 4 shows a schematic sectional end view taken at line IV-IV in Figure 1 0 3; and

Figure 5 shows a schematic part sectional plan view of a further embodiment of a locking mechanism in accordance with the invention.

In Figures 1 to 4 of the drawings, reference numeral 10 generally 145

indicates a locking mechanism in accordance with the invention. The locking

mechanism 10 is mounted on a closure member, in this case a hingedly displaceable door 1 2, which is in turn mounted on a support structure in the form of a door frame 14. The door 1 2 is hingedly displaceable between an open position 150 in which the door 12 exposes an opening defined by the door frame 14, and a

closed position in which the door 1 2 closes the opening.

The locking mechanism 10 includes a housing member 1 6 mounted on the door 12 by means of a nut 17 which is screwed on to the housing member

155 16 on the inner side of the door 12 to clamp the housing member 16 to the door

12. Although not shown in the drawings, the nut 17 has keyways for engaging keys on a fastening tool. It will be appreciated that, although, in this example, the housing member 1 6 is a component which is formed separately from the door 12,

the housing member 1 6 can, in other embodiments of the invention, be integrally

160 formed with the door 1 2, the door 1 2 and housing member 16, for instance, being

a unitary casting.

The mechanism 10 further includes an elongated shank 20 which passes through an opening 18 defined by the housing member 16 such that the

165 shank 20 is angularly displaceable about a longitudinal axis 26. A latch 28 is connected to the shank 20 at an end of the shank 20 which is the inner end of the

shank 20 relative to the door 12, the latch 28 being pivotally displaceable, in response to angular displacement of the shank 20, between a locked position in which the latch 28 is engaged with a keeper plate 30 fast with the door frame 14

to prevent opening of the door 1 2, and an unlocked position in which the latch 28 is free of the keeper plate 30, so that opening of the door 12 is allowed. The latch

28 is kept in position on the shank 20 by a lock-nut 29 which is screwingly engaged with the shank 20 such that the latch 28 is located between the lock-nut 29 and the housing member 1 6.

A coil spring 32 is provided around the shank 20, the spring 32 exerting a torque on the shank 20 to bias it towards a locking condition in which the latch 28 is in its locked position. To open the locking mechanism 10, the shank 20 therefore has to be angularly displaced against this bias.

It will be appreciated that the shank 20 is anchored against inward

longitudinal displacement by abutment of a disc 35 forming part of the shank 20 against an end wall in the housing member 16 in which the opening 18 is provided.

Furthermore, the spring 32 not only exerts a torque on the shank 20, but is somewhat axially compressed, so that the spring 32 exerts forces in opposed

longitudinal directions on the housing member 16 and the latch 28 respectively, urging them apart. The disc 35 is held by the spring 32 against the end wall of the housing member 16, and the shank 20 is anchored against outward longitudinal

displacement of the disc 35 away from said wall by the spring's 32 acting between

the housing member 16 and the latch 28. The shank 20 has a key-engaging end portion 34 adjacent the end of 195 the shank 20 remote from the latch 28, in other words adjacent the outer end of the shank 20 relative to the door 12. The key-engaging end portion 34 is non-

circular in outline when viewed in end view. In this case, the key-engaging end portion 34 of the shank 20 is right-circular-cylindrical, having five circumferentially

spaced axially extending formations, in this case flutes 36, on its cylindrically 2oo curved outer surface. The flutes 36 are spaced at regular angular intervals.

A security member 38 is connected end-to-end with the shank 20 at the key-engaging end of the shank 20, the security member 38 comprising a cover portion 42 and a boss 40. In this example, the cover portion 42 is independently

₂o5 rotatable relative to the shank 20. Both the cover portion 42 and the boss 40 are freely rotatable about an axis of rotation co-axial with the longitudinal axis 26 of

the shank 20, independently of each other, the cover portion 42 being located

between the boss 40 and the key-engaging end portion 34 of the shank 20. The cover portion 42 is disc-shaped with five circumferentially spaced axially extending

2io flutes 44 on its circumferentially extending radially outwardly facing surface. The

cover portion 42 thus has a periphery that, when viewed in end view, has a non- circular outline of the same shape as the outline of the key-engaging end portion 34 of the shank 20, when viewed in end view. However, the outline of the cover portion 42 is slightly larger than that of the key-engaging end portion 34 of the

215 shank 20 (although not visible in the drawings). The boss 40 is right-circular-cylindrical and projects in a longitudinal direction outwardly away from the cover portion 42, the boss 40 having a smaller 220 circumference than either the key-engaging end portion 34 of the shank 20 or the cover portion 42, when viewed in end view.

The housing member 1 6 defines a circular-cylindrical cavity 46 opening

out of the outer side of the door 12, a peripheral wall 48 which borders the cavity ₂₂5 46 extending around the key-engaging end portion 34 of the shank 20, the cover portion 42, and the boss 40. An annular space is thus defined between the

periphery of the key-engaging end portion 34 of the shank 20 and the peripheral wall 48 of the cavity 46.

230 The cavity 46 has a longitudinally outwardly opening key-receiving mouth 50 which is openably closed by a plug member, in this case a disc-shaped plug 52. The plug 52 is engaged with the housing member 1 6 by means of

complementary screw-thread 54 provided respectively on the circumferentially extending periphery of the plug 52 and on the peripheral wall 48 of the cavity 46

235 at the mouth 50. The plug 52 can thus be engaged with or disengaged from the housing member 16 by rotation of the plug 52 about an axis of rotation which is

aligned with the longitudinal axis of the cavity 46. The plug 52 has a key-engaging protuberance 56 protruding from its outer end face, the protuberance 56 being

circular when viewed in end view and having three circumferentially equally spaced

240 axially extending flutes 60. In another embodiment of the invention, which is not illustrated, the

mouth 50 of the cavity 46 is closed by a plug which comprises a lock for unlockably locking the plug in position in the mouth 50. The lock provides a bolt

which is radially displaceable into and out of engagement with a circumferentially extending mating groove in the peripheral wall 48 of the cavity 46. The lock can be key-operated, or it can be a combination lock.

The locking mechanism 10 forms part of a kit which further includes

an elongate key 62 which defines, at its one end, a socket 64 bordered by a

peripherally extending socket wall 66. The socket wall 66, when viewed in cross section, is complementary to the outline of the key-engaging end portion 34 of the

shank 20, when viewed in end view. In other words, in this example, the socket wall 66 is circular-cylindrical with five axially extending ribs or ridges 68, the ridges

68 corresponding in shape and in circumferential spacing to the flutes 36, 44 of both the cover portion 42 and the key-engaging end portion 34 of the shank 20, so that the socket 64 can receive, and transmit torque to, both the portion 34 and the member 42. The socket wall 66 thus has a thickness which is sufficiently small to allow longitudinal insertion of the key 62 into the annular space in the cavity 46 around the end portion 34 and the cover portion 42.

At the other end of the key 62, the key 62 defines a socket 70 which,

when viewed in cross-section, is complementary to the outline of the periphery of

protuberance 56 on the plug 52, in other words it is circular-cylindrical with three 265

circumferentially equally spaced axially extending ribs or ridges 72.

In use, the locking mechanism 10 locks the door 12 to the door frame 14 due to interference between the latch 28 and the keeper plate 30 forming part

27o of the door frame 14. The locking mechanism 10 is unlocked by angular

displacement of the shank 20 against the bias of the spring 32.

To remove the plug 52 from the mouth 50 of the cavity 46, the appropriate socket 70 of the key 62 is engaged with the disc's protuberance 56,

₂75 so that the ridges 72 of the associated socket 70 are received in the flutes 60 of the protuberance 56, allowing rotation of the plug 52 by the key 62 to unscrew the plug 52 from the housing member 16.

Thereafter, the key 62 is engaged with the locking mechanism 10 by 280 inserting the opposite end of the key 62 into the cavity 46 in a longitudinal

direction, so that the socket wall 66 of the key 62 passes into the annular space defined between the periphery of boss 40 and the peripheral wall 48 of the cavity 46. Usually, the flutes 44 of the cover portion 42 and the flutes 36 of the key- engaging end portion 34 of the shank 20 will be out of register at this stage. A

285 user thus aligns the ridges 68 of the socket 64 with the flutes 44 of the cover portion 42 and engages the socket 64 with the cover portion 42. Further

longitudinal insertion of the socket 64 is restricted by interference of the longitudinally outwardly facing surfaces of the ridges 68 of the socket wall 66 and 290 the axial surface of the key-engaging end portion 34 of the shank 20. The user then turns the key 62, and therefore the engaged cover portion 42, through a

sufficient angle until the flutes 44 of the cover portion 42 and the ridges 68 of the socket wall 66 are respectively in register with the flutes 36 of the key-engaging end portion 34 of the shank 20. The key 62 is then further displaced inwardly, so

295 that the key 62 engages the shank 20, the ridges 68 of the socket wall 66 being received in the mating flutes 36 of the key-engaging end portion 34 of the shank

20.

Once the key 62 is thus engaged with the shank 20, torque is applied 3oo to the shank 20 by angular displacement of the key 62, relative rotation of the key

62 and the shank 20 being prevented by interference between the periphery of the key-engaging end portion 34 of the shank 20 and the socket wall 66, so that the shank 20 is angularly displaced, against the bias of the spring 32, to disengage the latch 28 from the plate 30.

305

Unauthorised opening of the locking mechanism 10 tends to be

frustrated in that it is difficult, if not impossible, to turn the shank 20 effectively without an appropriate key 62. The peripheral wall 48 of the cavity 46 is sufficiently closely spaced from the key-engaging end portion 34 of the shank 20,

310 from the cover portion 42, and from the boss 40 for insertion of a conventional

gripping tool, such as a pair of pliers, into the cavity 46 to grip the shank 20 to be inhibited, if not prevented. Gripping of the boss 40 or the cover portion 42 in an attempt at opening the locking mechanism 10 is ineffective, since they are freely 315 rotatable relative to the shank 20.

The plug 52 serves the dual function of closing off the cavity 46 to inhibit the ingress of dust and moisture into it, and providing a further hinderance

to attempted unauthorised opening of the locking mechanism 10, particularly if it 320 has been screwed tight with the key 62, or if it is provided with a lock.

Figure 5 shows another embodiment of a locking mechanism in

accordance with the invention, designated 80, with like reference numerals indicating like parts in Figures 1 to 4 and Figure 5 of the drawings, unless

325 otherwise specified. In Figure 5, instead of having the door 1 2 locked by a latch

28 engaging a plate 30 on the door frame 14, the inner end of the shank 20

opposite the key-engaging end portion 34 is axially displaceably received in a hole 86 provided in the keeper plate 30. In this example, the door 12 is a sliding door, being openabje by sliding on the door frame 14 in a direction transverse to the

330 longitudinal axis 26 of the shank 20. Interference between the shank 20 and the

keeper plate 30 thus prevents opening of the door 12, with axially outward displacement of the shank 20 to a position where it is free of the keeper plate 30 allowing opening of the door 12.

335 Where the shank 20 passes through the opening 18 in the housing member 16, it is provided with an external screw-thread 88 which co-operates with a complementary internal screw-thread 90 in the opening 18, so that rotation of the

shank 20 causes axial displacement of the shank 20 through the opening 18. The 340 shank 20 can thus selectively be displaced between a locking condition in which

it prevents opening of the door 12, and an unlocked condition in which opening of the door 2 is permitted, by rotation of the shank 20 to cause it to move axially inwardly or outwardly, as the case may be.

345 A further distinction between the locking mechanism 10 shown in

Figures 1 to 4 and the locking mechanism 50 of Figure 5 is that the security member 38 comprises the boss 40 and a cover portion 92, the cover portion 92

and the boss 40 being integrally formed so that they are not independently

rotatable. The cover portion 92 corresponds in shape, dimensions and function to

350 the cover portion 42 of the locking mechanism 10.

In a variation of the locking mechanism of Figure 5, the shank 20 is

freely rotatably located in the hole 18 provided by the housing member 16, but the shank 20 is provided with an external screw-thread on an end portion of the shank

355 20 at its inner end. The door frame 1 has a nut provided thereon which has an internal screw-thread complementary to the screw-thread of the end portion of the

shank. This locking mechanism locks the door 1 2 to the door frame 14 by screwing of the screw-threaded end portion of the shank 20 into the nut provided

on the door frame 14. It will be appreciated that the door 12 can in this case be

360 removable from the door frame 14 in the direction of axis 26, being provided with a number of the locking mechanisms 80, each co-operating with an associated nut on the door frame 14.

In yet further embodiments of the invention (also not shown) the nut

1 7 of Figures 1 to 5 is replaced by a clamping element which fits over the housing

member 16 such that it is axially slidable relative thereto. In this case, the shank 20 is rotatably located in the opening 18. However, the shank 20 has a screw-

threaded portion located outside the housing member 16, the screw-threaded portion being screwingly received in a threaded hole defined by the clamping

element. It will be appreciated that the clamping element may be a single element, or it may be comprised of an arrangement of several parts, being eg cup-shaped.

Rotation of the shank 20 thus causes the clamping element, through

the clamping element's screw-threaded engagement with the shank 20, to be axially displaced towards or away from the door 12, as the case may be. The clamping of the door 12 between the housing member 16 and the clamping element can thus be tightened or loosened at the option of the user, by rotation of the shank 20 using the key 62. It will be appreciated that the door 12 will in this case be mounted on the door frame 14 such that the door 12 can be opened when

it is not clamped between the housing member 16 and the clamping element, the door 12 being locked to the door frame 14 when it is tightly clamped, eg when it is a sliding door. It will further be appreciated that instead of the locking mechanism's being provided on the door 12, it may be provided on a locking element, such as a locking latch or lever, for locking the door 12.

Claims

Claims:

390 1 . A locking mechanism for locking a closure member to a support structure, which locking mechanism includes:

an elongated shank having a key-engaging end portion which has a periphery

that is non-circular in outline when viewed in end view; a security member which is connected end-to-end with the shank at the key- 395 engaging end of the shank, the end-to-end connection being such that the security

member is freely rotatable about an axis of rotation which extends longitudinally

relative to the shank; and a housing member which defines an opening through which the shank passes, the shank being angularly displaceable about a longitudinal axis, 4oo the housing member being mountable on the closure member such that the shank

is angularly displaceable to move it between a locking condition in which the locking mechanism locks the closure member to the support structure, and an unlocked condition in which the locking mechanism is unlocked, so that the closure

member is displaceable relative to the support structure.

405

2. A locking mechanism as claimed in claim 1 , in which the housing member defines a cavity which has a longitudinally outwardly opening key-receiving mouth, the cavity being bordered by a peripheral wall which extends about the key- engaging end portion of the shank such that an annular space is defined between

4io the periphery of the key-engaging end portion of the shank and the peripheral wall

of the cavity.

3. A locking mechanism as claimed in claim 1 or claim 2, in which the

security member comprises a cover portion which has a periphery which, when 415 viewed in end view, has a non-circular outline of the same shape as the outline of the key-engaging end portion of the shank, when viewed in end view, the outline of the periphery of the security member being no smaller than that of the key-

engaging end portion of the shank.

20 4. A locking mechanism as claimed in 3, in which the peripheral outline of said cover portion is larger than the peripheral outline of the key-engaging end

portion of the shank.

5. A locking mechanism as claimed in claim 3 or claim 4, in which the

₄25 security member comprises a boss, the boss and the cover portion being freely

rotatable relative to each other and relative to the shank about a common axis of rotation, the cover portion being located between the key-engaging end portion of

the shank and the boss.

430 6. A locking mechanism as claimed in claim 3 or claim 4, in which the security member comprises a boss which is integrally formed with the cover

portion, the boss projecting in a longitudinal direction from the cover portion, and the cover portion being located between the key-engaging end portion of the shank and the boss.

435

7. A locking mechanism as claimed in any one of claims 3 to 6 inclusive, in which the key-engaging end portion of the shank is right-circular-cylindrical, having a plurality of circumferentially spaced axially extending formations on its

440 cylindrically curved outer surface.

8. A locking mechanism as claimed in claim 7, in which the formations on the key-engaging end portion are axially extending circumferentially spaced

flutes.

445

9. A locking mechanism as claimed in claim 8, in which the cover portion is disc-shaped, having a plurality of circumferentially spaced axially extending

formations on its circumferentially extending radially outwardly facing surface, the formations on the cover portion corresponding in circumferential spacing to that of

450 the formations of the key-engaging end portion of the shank.

10. A locking mechanism as claimed in any one of claims 1 to 9 inclusive, which includes a latch operatively connected to the shank, the latch being pivotally

displaceable in response to angular displacement of the shank between a locked

455 position corresponding to the locking condition of the shank and an unlocked

position corresponding to the unlocked condition of the shank, the latch being biassed towards its locked position.

1 1 . A locking mechanism as claimed in 10, which includes a spring which 460

exerts a torque on the shank to provide the bias of the latch towards its locked position.

12. A locking mechanism as claimed in any one of claims 1 to 9 inclusive,

465 in which an end of the shank opposite the key-engaging end is provided with a

screw-thread for engagement with a complementary screw-thread forming part of the support structure, thereby to lock the closure member to the support structure.

13. A locking mechanism as claimed in any one of claims 1 to 9 inclusive,

470 in which the shank, where it passes through the opening in the housing member, has an external screw-thread which co-operates with a complementary internal

screw-thread in the opening, so that rotation of the shank causes axial displacement of the shank through the opening.

475 14. A locking mechanism as claimed in any one of claims 1 to 13

inclusive, which has a plug member closing a mouth of the housing member, the plug member being removably connectable to the housing member by rotation of the plug member about an axis aligned longitudinally with the shank, the plug member having a key-engaging protuberance protruding from an outer end face of

480 the plug member, the protuberance having a non-circular peripheral outline when viewed in end view.

15. A locking mechanism as claimed in claim 14, in which the peripheral 485 outline of the protuberance on the plug member corresponds in shape and in

dimensions to the peripheral outline of the key-engaging end portion of the shank when viewed in end view.

1 6. A locking mechanism as claimed in claim 14 or claim 15, in which the 490 plug member is screw-threadedly engaged with the housing member at or adjacent the mouth of the housing member.

17. A locking mechanism as claimed in any one of claims 1 to 13 inclusive, which includes a plug member closing a mouth of the housing member,

495 the plug member incorporating a lock which unlockably locks the plug member in

the mouth.

18. A closure member which includes a locking mechanism as claimed in any one of claims 1 to 1 7 inclusive mounted on it.

500

19. A closure installation which includes:

a support structure which defines an opening; a closure member which is mounted on the support structure, being displaceable between an open position in which the opening is exposed, and a 505 closed position in which the closure member closes the opening; and

a locking mechanism as claimed in any one of claims 1 to 17 inclusive for unlockably locking the closure member in its closed position, the locking mechanism being mounted via its housing member on the closure member.

510

20. A kit for locking a closure member to a support structure defining an

opening, the kit including:

a locking mechanism as claimed in any one of claims 1 to 17 inclusive; and

a key for applying torque to the shank of the locking mechanism, the key

515 defining, at its one end, a socket bordered by a peripherally extending socket wall

which has an internal outline, when viewed in cross section, which is

complementary to the outline of the key-engaging end portion of the shank, when

viewed in end view, the socket wall being engageable with the key-engaging end

portion of the shank, so that the key-engaging end portion mates with the socket,

520 allowing torque to be applied to the shank.

21 . A locking mechanism as claimed in claim 1 , substantially as herein

described and illustrated.

525 22. A closure member as claimed in claim 1 8, substantially as herein

described and illustrated.

23. A closure installation as claimed in claim 1 9, substantially as herein

described and illustrated.

530

24. A kit as claimed in claim 20, substantially as herein described and illustrated.