GB2205604A - Locking device - Google Patents

Abstract

A locking device comprises a body (10) mounting a number of rotatable operating knobs (14), a bolt (15) slidable in the body between a retracted position, and an extended position in which part (18) of the bolt projects from the body to engage, and thus prevent movement of, a door or window handle (11), each knob being rotatable to any one of four stable positions, in three of which part of its outer surface engages at least one side wall (32, 33) of the bolt to prevent it sliding, and in the other of which it is clear of the bolt side walls to allow sliding, each knob (14) incorporating an indicia carrying element to indicate which of its stable positions it is in, it being possible to change the indicia relative to each knob position in order to alter the 'code' of the locking device. <IMAGE>

Description

LOCKING DEVICE This invention relates to a locking device, principally a locking device which is associated with an operating member for opening and closing a window or door.

The object of the invention is to provide a locking device in a convenient and efficient manner.

According to the invention a locking device comprises a body, a locking member slidable in the body between a first position where part of the member extends out of the body, and a second position where said part is received in the body or is retracted from said first position towards the body, and an operating member mounted at the body for movement between one position where part of the operating member co-operates with the locking member to prevent sliding thereof, and a further position where the locking member can slide relative to said operating member.

Preferably the operating member is mounted on the body for rotation relative thereto.

Desirably the operating member has a multiplicity of rotation positions in which it prevents the sliding of the locking member, and a single rotation position in which it can take place.

Advantageously at least two operating members are provided. Each operating member is preferably a manually rotational knob having four equi-angularly spaced stable positions of rotation, in three of which sliding of the locking member, in the form of a bolt, is prevented by engagement therewith of the operating member, and in one of which such sliding can take place.

Desirably each of the four positions corresponds to a different number on the operating member being aligned with an indicator on the body so that knowing the correct number for each operating member, each of the operating members can be rotated to the correct position to allow sliding of the locking device.

Advantageously the number corresponding to the rotation position which releases the bolt for each knob, can be altered by rotating relative to the knob an insert which carries the numbers (or other indicia).

The invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a side view of a locking device of the invention incorporated with a handle intended for use in opening and closing a window, Figure 2 is a top plan view of Figure 1, Figure 3 is an enlarged, fragmentary, part-sectional side view showing the locking device of Figure 1, Figure 4 is a part-sectional plan view of Figure 3, Figures 5 to 7 are top plan, underneath plan and inverted longitudinal sectional views respectively of a body of the locking device, Figures 8 to 10 are top plan, underneath plan and longitudinal sectional views respectively of a bolt of the locking device, Figure 11 is a top plan view of an operating knob of the locking device, Figures 12 to 14 are views of three sides of the knob respectively, Figure 15 is an underneath plan view of the knob, Figures 16 and 17 are sectional views on the lines 16-16 and 17-17 respectively in Figure 11, Figure 18 is a view of one side of a setting insert of the locking device, Figures 19 and 20 are top plan and underneath plan views respectively of the insert of Figure 18, and Figures 21 and 22 are cross-sectional views on the lines 21-21 and 22-22 respectively in Figure 18.

Figures 1 and 2 show a lockable handle assembly intended for use with a window. The assembly comprises an elongate, generally rectangular body or housing 10, shown in Figures 5 to 7, and a hand-grip shaped lever handle 11. At its one end the housing has a raised platform part 12 on which the handle 11 is mounted for angular movement. The invention is not related to the particular actuation which results from angular movement of the handle, though in one application rotation of the handle rotates a gear which drives a rack on a locking bar which causes secure locking of the window relative to its frame when the handle is in its rest position aligned with the housing 10, as shown in Figures 1 to 4.

The embodiment of the invention to be described does in fact relate to the locking of the handle in its rest position by means of a combination-type locking device, although the locking device of the invention is considered to have much wider application than the locking of window or door operating members.

Figures 1 and 2 show how the nousing 10 is formed at its end remote from the handle pivot part 12, with a similarly raised part 13 at which are mounted three manually rotational locking knobs 14. Within the part 13 is slidably disposed a locking member in the form of an elongate bolt 15, shown in Figures 3 and 4, and in detail in Figures 5 to 7. The housing part 13 has slots 16, 17 respectively at its opposite ends and in one extreme position of the bolt, as shown in Figures 1 to 4, a cylindrical end projection 18 of the bolt extends through the slot 16.

The end part of the handle 11 remote from its pivot extends over and is shaped to match the end of the body part 13 and a lower end web 19 of the handle lies adjacent the slot 16 when the handle is in its rest position. This web 19 has a circular section aperture 19a there through and in the extreme position of the bolt described, the projection 18 extends through slot 16 and into the aperture l9a, thereby preventing pivotal movement of the handle.

Sliding movement of the bolt 15 to its other extreme position, i.e. to the left as shown in Figures 3 and 4, withdraws the projection 18 from the handle, whilst an indicating projection 20 extends through the slot 17 to indicate that the handle is unrestrained by the bolt.

Similarly if the projection 20 is not extending out the slot, it is evident that the bolt is holding the handle captive.

The knobs 14, as will hereinafter be fully described, can be rotated so as to hold the bolt against sliding movement or to release it to allow such sliding, thereby controlling the locking or release of the handle.

Details of the locking device components will now be described.

As has been generally described, the housing 10 is, in this example, a one-piece construction combining the handle pivot base and the lock body. In a possible alternative construction these parts could be separate.

As shown in Figures 5 to 7, the housing is of elongate, rectangular shape having an inverted shallow channel form, with the parts 12 and 13 extending out from the base wall 21 of the channel. The end of the housing 10 adjacent the part 12 can be provided with a countersunk screw hole 22 for fixing the housing to a window, and a further such screw hole 23 is provided in the outer flat surface of the part 12, the screw hole 23 being concealed in use by the handle 11.

The part 13 has a sloping end surface 24 facing the part 12, and having the slot 16 therein. The outer, flat surface 25 of the part 13 has three centrally disposed, longitudinally aligned, equi-spaced circular-section holes 26, 27, 28 respectively provided therein. As can be seen from Figure 7, each hole has a depth greater than the wall thickness of the outer surface 25, each hole terminating in a plane parallel to the surface 25 and lying just below half way along the slot 16. The holes thus have respective annular lower surfaces 26a, 27a, 28a. On the outer surface 25 adjacent its other end surface 29 is a centrally disposed raised arrowhead 30, directed along the aligned centres of the holes 26-28. In the surface 29, which is normal to the surface 25 is the slot 17, which is rectangular. The housing is preferably made of zinc.

When all the appropriate components of the lockable window handle assembly have been assembled the housing can be secured appropriately in place at a window by screws in the holes 22, 23. Additionally a mounting plate 10a closes part of the open rear of the housing, the mounting plate having an end lug fitting in a slot 31 in the surface 29 below the slot 17, and itself being received in the shallow channel part of the housing 10. The plate, which terminates short of the handle pivot part 12, is formed with a pair of longitudinally spaced countersunk screw holes for securing it to the window.

The bolt 15 is, like the housing, a zinc die-cast component, and is generally in the form of an elongate, rectangular channel-shaped element, upstanding side walls 32, 33, the wall 33 being spaced slightly inwards from its adjacent edge 34 of the parallel longitudinal edges 34, 35 of a flat base 36 of the channel. Parallel end walls 37, 38 lie normal to the base 36. The cylindrical end projection 18 extends normally outwardly from the end wall 37 whilst a rectangular projection 39 extends normally outwardly from the end wall 38 at the same level as the projection 18. The projection 39 has a small cam ramp 40 on its lower surface. A plastics material cap 41 can be fitted over the projection 39 with the ramp 40 being received in a hole 42 (Figure 3) in the lower cap wall.The cam ramp deforms the lower cap wall as the cap is pushed onto the projection, the wall thereafter snapping onto the ramp when it engages in the hole 42. The projection 39 and cap 41 form the indicating projection 20. The projections 18 and 39 lie along a longitudinal centre line of the bolt.

The side wall 32 of the bolt is formed with three equally longitudinally spaced arcuate portions 43, 44, 45 respectively, the arcuate portions being parts of respective circles having their centres on the bolt longitudinal centre line. The portions 45 and 44 are joined by a straight part 46 of the wall 32, the portions 44 and 43 are joined by a straight part 47, and a straight part 48 extends from the portion 43 to the end wall 37. The straight parts lie in a common plane spaced inwardly of and parallel to the edge 34 whilst the outermost part of each arcuate portion just reaches the edge 34. Each arcuate portion extends over approximately 110 of arc.

The opposite side wall 33 is formed with corresponding arcuate portions 43a, 44a, 45a also being parts of the aforementioned circles centred on the bolt longitudinal centre line. However the arcuate portions of the side wall 33 extend over only approximately 700 of arc.

Consequently the corresponding straight parts 46a, 47a and 48a are longer and are spaced a greater distance from the bolt longitudinal centre line. The diameter of each of said circles is substantially equal to the diameter of each of the holes 26-28 in the housing.

In the base 36 are three circular through holes 49 also centred on the bolt longitudinal centre line and equi-spaced therealong. Each hole has a radius such that the holes just extend to the three straight parts respectively of the side wall 32, but do not reach the equivalent parts of the side wall 33 in view of their greater spacing from the bolt longitudinal centre line.

The distance between the centre of a hole 49 and the centre of the adjacent circle defining the arcuate portions of the side walls 32, 33 is equal to the maximum amount of sliding movement the bolt can make in the housing 10. This movement will now be described.

The bolt 15 is fitted in the housing 10 as shown in Figure 3, the outer surface of the base 36 lying flush with the outwardly facing surface of the base wall 21 of the channel form of the housing. It is held in this position by the mounting plate previously referred to.

The bolt width substantially matches the internal width of the part 13 and its length is longer than the length of the part 13. The bolt is slidably arranged in the part for movement between two extreme positions.

One extreme position is shown in Figures 3 and 4, where the bolt end wall 38 abuts a depending side surface of the hole 28 which faces end surface 29 of the housing.

Additionally in this position the projection 18 extends through slot 16 into aperture 19a in the handle and its end surface abuts against a second web 50 of the handle. Both these described abutment states of the bolt prevent movement of it to the right as viewed in Figure 3. In this state the projection 20 is substantially received in the housing to indicate that the handle is locked against movement, and the centres of the holes 26-28 are aligned with the centres of the circles describing the arcuate portions of the bolt side walls respectively. A coiled compression spring 51 between the housing end wall 24 and the bolt end wall 37 biases the bolt to the other extreme position.

The other extreme position of the bolt occurs if it is slid as far as possible to the left as viewed in Figure 3 this, as explained above, being in accordance with the action of the spring 51. When the bolt is slid to the left, the projection 18 slides out of the aperture 19a in the handle so that the handle is then free to be moved angularly. As sliding of the bolt continues the inner surface of the bolt end wall 37 abuts a depending side surface of the hole 26 which faces end surface 24 of the housing, and the outer surface of the bolt end wall 38 abuts the inner surface of housing end wall 29.

The projection 18 is thus substantially withdrawn into the housing and the indicator extended out of the housing through slot 17. In this other extreme position, the centres of the holes 26-28 are aligned with the centres of the holes 49 in the bolt respectively.

Each knob 14 is constructed of two parts of plastics material, namely an outer locking knob 52 part and an inner insert 53.

The part 52 is in the general form of a stepped cylindrical knob, having an outer surface consisting of an upper knurled or ribbed hand-grip part 54 which is then stepped inwardly by way of an annular shoulder 55 to a remaining smooth cylindrical surface 56. The outer diameter of surface 56 is substantially equal to the diameter of the circles defining the arcuate parts of the bolt side walls. Inwardly, the part 52 has a circular section opening 57 in the part 54 which is connected by a step forming an annular shoulder 58 to a cylindrical bore 59, which itself is connected to a square-section bore 60 by a shoulder 61. The bore 60 communicates with a generally D-shaped opening 62 in the bottom of the part 52 by means of a shoulder 63.

The outer surface 56 is not cylindrical around all of its periphery. At one side, as shown in Figure 12, the surface is formed with a cut-out defining a flexible arm 64 with slots 64a through the wall thickness of the part 52 at its longitudinal sides. At its lower free end the arm has a cam or ramp surface 65. Below the free end of the arm, the outer cylindrical surface 56 is cut away inwardly to define a flat surface 66 at the bottom of the part 52, with a radially inwardly arcuate surface 67 above it and extending upwardly to the level of the shoulder 61 and thus into the interior of the part 52 at the bottom of the bore 59, as shown best in Figure 17.

At the diametrically opposite side of part 52, shown in Figure 13, a similar further flexible arm 68 with ramp surface 69 and adjacent slots 68a is formed. Below the free end of arm 68 the cylindrical surface is again cut away inwardly to form a flat surface 70, parallel to flat surface 66. However the flat surface 70 is longer than the flat surface 66, as can best be seen from Figure 15, as it lies closer to the rotational centre axis of the part 52 than the flat surface 66. In fact the centre of the surface 70 lies at the same distance from the centre axis as the surface 67, so that the surface 70 extends upwardly into the interior of the part 52 at the shoulder 61, as shown in Figure 17. The D-shaped opening 62 is formed by two spaced parallel flat surfaces 71 extending normally inwardly from the surface 70 and being connected by an arcuate surface 72.

The distance between the shoulder 55 and an upper flat surface of each of the ramp surfaces 65, 69 is substantially equal to the depth of each of the holes 26-28. Accordingly a part can be engaged with the housing 10 in the manner shown in Figure 3, where the part 52 is forced downwardly into one of the holes 26, 27, 28. As the part is forced down the inclined ramp surfaces 65, 69 engage diametrically opposite interior surfaces of the hole and are thus forced inwardly, being of flexible form. As the part is further forced down, the surfaces 65, 69 eventually clear the depending cylindrical hole surfaces and thus spring back to their normal positions.In view of the spacing referred to above between the shoulder 55 and the upper ramp surfaces, the shoulder bears on the outer flat surface 25 of the housing around the hole, whilst the upper, flat ramp surface tightly engage diametrically opposite portions of the lower annular surface of the bole. Thus the part is held against any axial movement, but can be rotated in the hole. The lowermost surface of the part 52 is disposed slightly above the upper surface of the base of the bolt. In use three such parts are engaged in the three holes 26-28 respectively.

When a part 52 is finally fitted in the housing, the lower portion of the outer surface of a part 52 is disposed between the bolt side walls 32, 33, this lower portion having an outer periphery consisting of the two parallel flat surfaces 66, 70 joined by two arcuate surfaces, each having a radius of curvature matching the opposite arcuate portions of the bolt side walls.

The spacing between the flat portions 66, 70 is less than the internal distance between facing straight parts of the bolt side walls. However as described above, the flat portions are not symmetrically disposed at opposite ' sides of a parallel plane through the centre axis of the part 52.

The result of these constructional features is that when fitting a part 52 into a hole in the housing, the bolt should be in its extreme right position where the projection is fully extended and the holes 26-28 are aligned with the arcuate portions of the bolt side walls respectively. The bolt would thus need to be held against spring 51. In this position a part can be fitted in any one of the holes 26-28 with its lower portion being received between the bolt side walls, whatever its rotational orientation.

However it is convenient to define four stable rotational positions of a part relative to the housing, and thus relative to the bolt. A first position is where the flat surfaces 66, 70 are normal to the longitudinal extent of the bolt with the surface 66, for example, facing to the left. This is shown in Figure 4 for the extreme left part. A second position is that shown for the next part 52 shown in Figure 4, where the part is rotated through 900 in a clockwise direction so that surface 66 is parallel to bolt edges 34, 35 and facing away from side wall 33. A third position would be that reached by a further 900 clockwise rotation, so that surfaces 66, 70 were again normal to the bolt edges 34, 35, but with surface 66 now facing to the right. Finally a further 900 clockwise rotation would bring the surfaces 66, 70 parallel to bolt edges 34, 35, with surface 66 facing side wall 33.Only in this fourth position would no part of either of the arcuate surfaces joining the flat surfaces 66, 70 be within the arcuate portions of the bolt side walls.

Accordingly once one part 52 has been fitted in either of the first three stable positions referred to, the bolt need no longer be held against its spring, as the engagement of the lower portion of the part 52 with the bolt side wall arcuate portions prevents the bolt from sliding to the left.

If it were attempted to fit a part 52 with the bolt in its extreme left position, so that even initially it did not need to be held, then the part 52 would have to be in its fourth position so that the flat surfaces 66, 70 could be received parallel to and between facing straight parts of the bolt side walls, with the surface 66 facing side wall 33. As can be deduced from Figure 4, if the surface 70 were to face side wall 33, the surface 66 would extend over the side wall 32 and the part 52 could not be forced into its intended hole in the casing.

It will thus now be apparent that once all three rotational parts 52 are fitted in the housing, the rotation of said parts control whether or not the bolt can slide. Accordingly the parts constitute manually operable members for locking or unlocking the handle 11 by locking the projection 18 with the handle or unlocking it therefrom.

Thus under normal operation, the orientations of the parts 51 are arranged so that the spring 51 forces the bolt to its extreme left position where the projection is withdrawn from the handle aperture 19a and the handle is free to be moved angularly about its pivot.

The indicating projection 20 is extended to denote that the handle is unlocked. When it is desired to lock the handle in position, the handle is firstly aligned with the housing as shown in Figures 1 to 4. Then the projection 20 is pushed fully into the housing against its spring, as shown best in Figure 3, so that the projection 18 enters the aperture 19a and prevents movement of the handle. The sliding of the bolt aligns the holes 26-28 with the arcuate side wall portions of the bolt. With the bolt held against its spring, each part 52 is then rotated from its present position, which is position four, to a selected one of the other positions. Of course locking would occur if only one part were eventually rotated to a position different from position four.

Once one or more of the parts is or are thus rotated to prevent sliding movement of the bolt, it is intended that the handle is then locked until someone knowing the lock combination correctly operates the parts, whereon the spring automatically releases the bolt.

If an unauthorised person attempts to release the lock, it will be understood that there are 4x4x4 combinations which may have to be tried in order to be successful.

Obviously a further part would increase these to 256.

Thus the lock has an effective degree of security.

In order to identify each of the four stable positions, a plastics material insert 53 (Figures 18 to 21) is fitted in each part 52. The insert has a circular head 73 with indicia, such as the numbers 1 to 4, moulded on its outer face, and arranged at 900 intervals therearound for alignment with the arrowhead 30 on the housing to identify the setting of each of the knobs 14.

Depending from the head 73 is a cruciform-section upper shank part 74 which joins a middle shank part 75 of circular section having a diameter just less than a side of the bore 60. Along its lower length, the shank part 75 is bifurcated defining two legs 76, a lower shank part 77 being of square cross-section just less than that of the bore 60. The part 77 continues the bifurcation of part 75 and the ends of the legs thus each have a rectangular section, along the outer longer side. of which extends a ramp 78.

In use an insert or setting dial 53, with a coiled compression spring 79 around its shank, is forced shank first into a part 52 so that the ramps 78 engage the inner surface of the bore 60 and the flexible legs are pressed inwardly towards each other. As the ramps clear the bottom of the bore 60 the legs spring back outwardly and the respective flat upper surfaces of the ramps engage the shoulder 63. The leading end of the inserted spring bears on the shoulder 61 of the part 52 with its other end bearing on the underside of the head 73, the spring thus being compressed to bias the insert upwardly. The bottom of each leg at the level of its associated ramp is thus received in the opening 62 and is just above the base 36 of the bolt.The upper portion of the square-section shank part 77 is thus a close sliding fit in the complementarily shaped bore 60 and prevents rotation of the insert.

It is thus quite possible to operate the lock as described, with the combination being identified by means of which number on each knob is aligned with the arrowhead 30 in stable position four, the insert in each part being initially fitted therein with one number aligned with the arrowhead.

However if it is wished to change the combination, for example if it were suspected that the original combination had become known to an unauthorised person, this can be carried out as follows.

Firstly, if necessary, the knobs are rotated to release the bolt to its extreme left or unlocked position.

This aligns the holes 26-28 with the holes 49 in the bolt. The head of each insert is then pressed down against its spring so that the upper portion of the square-section shank part 77 is moved out of the bore 60, the ramps moving down into the holes 49 in the bolt base 36 and the upper portion of part 77 moving into the larger opening 62. As the shank section in the square bore 60 is now the circular section 75, the insert can be rotated to bring a different number into alignment with the arrowhead 30. Each of the three inserts can be altered in this manner. The heads thereof are then released and the springs 79 return the inserts to their non-rotational positions, each knob now having a new numeral identifying its fourth stable rotational position in which it releases the bolt.

As well as locking the handle in a position where the window is fully closed, it would of course also be possible to lock it in a night vent position by provision of a suitable hole in the handle.

Additionally the fastener could be of the wedge type disclosed in our U.K. early published specification No. 2169949.

Described and illustrated herein is thus one embodiment of the invention in the form of a lockable door or window operating member. Although the locking device is easy to use, it is effective in use and is easily adaptable to vary the degree of security it provides for any particular application. There is no key or other locking element which could become lost or fall into the hands of an unauthorised person.

Moreover the invention is clearly applicable to a great variety of applications, in fact wherever it is required to lock a member in a particular position, this can be achieved by engaging part of the bolt or other locking member with the member to be locked.

Clearly the member to be locked could move in a different plane of movement from the locking member.

For example, in the present invention, the handle could still be locked in the same manner if it pivoted vertically towards and away from the housing, as viewed in Figures 1 and 3.

With the arrangement described, there is a possibility that a knob could be prised out of its hole in the housing, for example by the insertion of a blade between the shoulder 55 of the knob and the housing surface 25, despite the engagement provided by the ends of the flexible arms 64 and 68 at the lower annular surface of the hole. Accordingly in a further embodiment the arms are replaced by a continuous annular flange around the outer surface of a knob at the level of the ramp parts at the lower ends of the arms. Additionally the step forming the shoulder 55 is omitted so that the ribbed part 54 is the same diameter as the surface 56 and is thus not enlarged relative thereto.Accordingly on assembly, such a knob can be inserted upwardly into its hole, the housing being orientated as shown in Figure 3, with the part 54 being received above the surface 25 and the upper annular surface of the flange engaging the lower annular surface of the hole to limit the upward knob insertion. Once the bolt is assembled in the housing, the knob is prevented from dropping downwardly out of the housing. Thus not only is there no longer the shoulder 55 under which a blade could be inserted, but the flange provides engagement all the way round the knob with the annular lower surface of the hole. The flange preferably extends radially outwardly by a distance greater than the radial ramp projection at the end of each arm 64, 68.

In one alternative embodiment of the invention, an operating knob 52 and insert 53 are effectively shortened so that the top of the knob assembly is flush with or just below the surface 25. To rotate the assembly from outside the body thus requires a special tool to be fitted in a correspondingly specially shaped opening in the top of the knob assembly. For example the opening could be hexagonal for engagement by an Allen key. The need for a special tool means that a single knob assembly can provide sufficient security, so the remaining holes in the body can be blanked off.

In a further alternative embodiment, an operating knob assembly is replaced by a die cast socket securely fitted in the hole in the body. The socket has a central, threaded hole therethrough and received therein is a grub screw or the like. In the locking position of the bolt 15, Figure 2, a special tool is engaged in an appropriate opening in the top of the grub screw, and the tool is used to screw the grub screw down so that the lower end of the grub screw is received into an opening in the base of the bolt, when in its locking position, to prevent the bolt sliding.

In this position the top of the grub screw is disposed below the top surface of the socket, which is itself flush with surface 25. Thus rotation of the grub screw sufficiently to engage in the opening in the bolt requires the special tool, which again could be an Allen key fitting in a hexagonal opening in the top of the grub screw. Again the other holes can be blanked off, and the bolt side walls can be straight, since they are not now engaged by a knob when the bolt movement is prevented.

Claims (21)

1. A locking device comprising a body, a locking member slidable in the body between a first position where part of the member extends out of the body, and a second position where said part is received in the body or is retracted from said first position towards the body, and an operating member mounted at the body for movement between one position where part of the operating member co-operates with the locking member to prevent sliding thereof, and a further position where the locking member can slide relative to said operating member.

2. A locking device as claimed in claim 1, wherein the operating member is mounted on the body for rotation relative thereto about a first axis.

3. A locking device as claimed in claim 2, wherein the locking member defines a location laterally of its sliding direction into which said part of the operating member is received in said one position and of which said part is clear in said further position.

4. A locking device as claimed in claim 3, wherein the locking member has a side wall which extends generally in the sliding direction of the locking member, the lateral location being a recess defined by an outwardly arcuate part of the side wall.

5. A locking device as claimed in claim 4, wherein said arcuate part of the side wall is itself part of a circle centred on said first axis.

6. A locking device as claimed in claim 5, wherein the operating member has an outer cylindrical surface which is interrupted at diametrically opposed positions by respective flats, the curvature of said outer surface matching that of said circle centred on said first axis.

7. A locking device as claimed in claim 6, wherein a longitudinal centre line of the locking member passes through said first axis, and a first distance is defined between said centre line and a plane through the parts of the side wall extending in the sliding direction of the locking member, said arcuate part of the side wall lying outwardly of said plane, a longer one of the flats being spaced by a second distance and the shorter one by a third distance from a plane parallel to the flats and through the first axis, the first distance being greater than the second distance and shorter than the third distance, so that in said one position the shorter flat or part of the cylindrical surface is received in said location to prevent sliding of the locking member, and is clear of the recess in said further position.

8. A locking device as claimed in claim 6 or claim 7, wherein the operating member is rotatably fitted in a hole in the body so that a grip part at one end of the operating member projects outside the body, with the flats being at the opposite end of the operating member and thus disposed within the body.

9. A locking device as claimed in claim 8, wherein retaining means is provided on the outer surface of the operating member to engage an undersurface of said hole in the body to resist outward movement of the operating member.

10. A locking device as claimed in claim 7, wherein the operating member comprises means for identifying possible stable rotation positions thereof.

11. A locking device as claimed in claim 10, wherein said means is an insert received within the operating member and carrying indicia which are visible outwardly of the body to identify each of four stable rotation positions of the operating member relative to the body.

12. A locking device as claimed in claim 11, wherein the insert is held against rotation relative to the operating member when the locking member is in its first position, but when the locking member is in its second position the insert can be moved relative to the operating member against spring bias, so that its end in the body is received in an opening in a base of the locking member, and then rotated relative to the operating member to change the relationship between the indicia and the stable positions of the operating member.

13. A locking device as claimed in claim 12, wherein a shank of the insert has a non-circular external surface part and an adjacent circular surface part, the non-circular part being received in a complementarily shaped bore in the operating member when the insert is spring biased upwardly in the operating member, thereby preventing rotation of the insert, said movement of the insert against said spring bias bringing the circular section part into said bore to allow rotation.

14. A locking device as claimed in any one of claims 11 to 13, wherein the insert is a snap-fit in the operating member.

15. A locking device as claimed in any one of the preceding claims, wherein said part of the locking member is an elongated projection at one end of the locking member intended to engage in an opening of a member to be locked, when the locking member is in its first position.

16. A locking device as claimed in claim 15, wherein at the other end of the locking member is an indicating device which projects from the body when the locking member is in its second position and is received in the body when the locking member is in its first position.

17. A locking device as claimed in claim 15 or claim 16, wherein the locking member is biased to its second position.

18. A locking device as claimed in any one of claims 3 to 14, wherein at least two identical operating members are rotatably mounted on the body, the locking member defining respective longitudinally spaced lateral locations for receiving parts of the operating members when the locking member is in its first position, the locking member being slidable to its second position only when all of the operating members have been rotated to respective positions where they are clear of said locations.

19. A lockable handle assembly for a door, window or other wing, including a locking device as claimed in any of the preceding claims.

20. A locking device substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

21. A lockable handle assembly including a locking device substantially as hereinbefore described with reference to and as shown in the accompanying drawings.