GB2129864A - Door or window fasteners - Google Patents

Description

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GB 2 129 864 A 1

SPECIFICATION

Locking devices and assemblies incorporating such devices

This invention relates to locking devices of the 5 kind intended for releasably securing together two relatively movable members comprising a panellike structure which is movable relative to a further structure which may comprise an external frame or further, movable or fixed panel-like structure. 10 More particularly, the invention is concerned with a locking device for securing hinged or sliding windows or doors, in a closed position with respect to an external frame or further window or door.

15 Traditionally, windows have been secured in a closed position by means of one or two catches carried by a movable sash frame which engage with a respective keeper provided on an adjacent fixed frame or on an adjacent window, such 20 catches having an operating handle which is often visually rather unsightly, and moreover is easily accessible to an intruder by breaking the window pane. Further, on larger windows, especially where hinged on a vertical axis, it may be difficult 25 for a user to operate both catches and some form of mechanical interlinking external to the sash frame may be provided.

Systems have been developed whereby a single handle member serves to operate two or more 30 spaced latching devices by means of a rod or cable mechanism housed within the movable sash frame, particularly in association with windows which are optionally openable about either a vertical or a horizontal axis according to the user's 35 requirements. However, such systems are complex and can be accommodated only in heavy frames formed from members whose cross-sectional dimensions are more than about 5 cm x 5 cm. Accordingly, such systems are only 40 suitable for use with the larger sizes of window which require the use of such sturdy frames. A typical example is that shown in British Patent Specification 1,389,131.

Such known systems employ operating 45 mechanisms which include a member that is rotatable about a fixed axis perpendicular to the plane of the window, and offset from the movable element. Typically, a rack and pinion type mechanism is employed, as shown for example in 50 British Patent Specification 1,327,238. The use of such a mechanism is one major factor which determines the minimum dimensions of a frame element within which such a locking system can be accommodated.

55 One object of the invention is to provide a locking device which is suitable for use with frame members of smaller cross-sectional dimensions so as to enable such a concealed locking system to be employed more conveniently with lighter and 60 smaller windows.

According to one aspect of the invention, we provide a door or window assembly of the kind comprising a door or window panel structure movable relative to a further structure between a closed position and one or more open positions, said structures each including respective edge members which come substantially together in the closed position with facing parts thereof at least partially in spaced relation, wherein a locking device for retaining said structures releasably in the closed position comprises one or more catch formations formed or provided on or adjacent to the facing part of the edge member of one of said structures, and a locking mechanism mounted on or adjacent to the facing part of the edge member of the other of said structures, which mechanism comprises a movable element guided for movement longitudinally of the edge member and formed or provided with one or more co-operative locking formations adapted to co-operate with said catch formations to prevent movement of said panel structure from the closed position, the movable element being formed or provided with an operating element which is engageable by a lever having a fulcrum at a position offset from the longitudinal axis of the movable member in a direction transverse to the direction in which said facing parts are spaced when the structures are in said closed position.

It will be appreciated that, in use, the lever will extend in a plane close to, or even containing the longitudinal axis of the movable element. In this way, the locking mechanism can be made very shallow so as to be capable of use with smaller section frame elements than previously known concealed locking systems. In particular, instead of being provided internally of a hollow section edge member, the locking mechanism in accordance with this aspect of the invention is located externally of the edge member in the very restricted space available between the two edge members, which may typically be about 14 mm in width.

For increased security, the lever may be releasably engageable with the operating element and removably associated with the mechanism, the lever extending through an aperture in the edge member on which the mechanism is carried, and said aperture preferably affording a bearing surface serving as said fulcrum. Alternatively, the fulcrum may comprise a bearing surface provided adjacent to said aperture.

In a further arrangement, the lever may be pivotally mounted on the edge member on which the locking mechanism is carried, in such a manner that it is not normally removable.

The operating element may be mounted on said movable element for rotation about an axis which extends transverse to the length of thermovable element and transverse to the facing part of the edge member on which the movable element is mounted. Alternatively the operating element may simply comprise an apertured portion of the movable element adapted to receive the end of said lever.

The movable element may extend over substantially the entire length of the edge member on which it is carried and afford a plurality of said locking formations at regular intervals, and an

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equivalent number of said catch formations then being provided conveniently on an elongated base member at similar spacings.

Conveniently, the operating element is provided 5 at one end of said movable element so that the movable element can be formed by severing a single piece from a stock length of suitable material having said catch members provided or integrally formed thereon, and so that in use the 10 operating element can be positioned near to the bottom end of an upright edge of the door or window.

Whilst in the case of a hinged door or window, such a locking device would normally be provided 15 only at the edge opposed to the hinged edge, it will be appreciated that additionally or alternatively the locking device in accordance with the invention could be provided at one or both edges adjacent to the hinged edge, possibly in 20 addition to a conventional catch.

When the assembly includes an outwardly opening door or window, the movable element of the locking mechanism may be carried at the inner periphery of the external frame. However, if the 25 door or window is inwardly opening, the movable element of the locking mechanism may be provided on the door or window itself. Further, the locking mechanism in accordance with this aspect of the invention may be utilised in a sliding door or 30 window assembly to lock a sliding door or window relative to an external frame or to a further fixed or sliding door or window.

It will also be appreciated that a removable panel structure may be secured in a frame 35 structure by means of such locking devices at respective opposed sides.

From a further aspect, the invention also resides in a door or window assembly comprising two structures which are relatively movable 40 between one or more open positions and a closed position in which edge members of the two structures are brought at least substantially into engagement, wherein said edge members in the closed position have facing parts thereof at least 45 partially in spaced relation, and a locking device for securing the two structures releasably in the closed position concealed within a space defined between said facing parts, the locking device being operable by means of a lever which extends 50 into said space through a flange which forms a lateral boundary of said space.

In accordance with a more general aspect of the invention, we also provide a door or window assembly for installation in an aperture formed for ' 55 that purpose in a building, comprising an openable door or window structure and a further structure comprising a surrounding frame or a further door or window structure which in either case includes an edge member forming part of the boundary of 60 an opening which can be closed by the openable door or window structure, said openable structure having an edge member which is movable into and out of contact with said edge member of the further structure, wherein one of said edge 65 members carries a concealed locking mechanism having one or more locking formations adapted to co-operate with one or more corresponding catch formations formed or provided on the other of said edge members, the mechanism being operable by means of a lever which extends through an aperture in the edge member which carries the mechanism, the lever then being pivotable about a fulcrum afforded by said aperture or provided adjacent thereto.

Additionally, the invention further resides in such an assembly in an opening formed for that purpose in an internal or external wall of a domestic, industrial or commercial building.

These and other features of the invention will now be described by way of example, with reference to the accompanying drawings, wherein:—

FIGURE 1 is a perspective view of a hinged window assembly incorporating a locking device in accordance with the invention;

FIGURE 2 is a fragmentary view in the direction of arrow 2 showing part of the locking device installed on an edge member forming part of a fixed frame as shown in Figure 1;

FIGURE 3 is a fragmentary view in the direction of arrow 3 showing a further part of the locking device installed on an edge member forming part of an outwardly opening window as shown in Figure 1;

FIGURES 4a, 4b and 4c are respectively transverse sections on the lines A—A, B—B and C—C of Figure 2, but with the window in its closed position; and

FIGURES 5 and 6 are transverse sectional views similar to Figure 4a showing further embodiments of the invention as applied to a sliding door or window assembly.

As shown in Figure 1, an outwardly opening sash frame 10 is mounted by means of hinges 11 on one edge of an external frame 20 which is, in use, secured in an opening formed for this purpose in a wall of a building. Whilst Figure 1 shows a glazed window, it will be appreciated that the invention may be applied to hinged doors, whether glazed or not, and other similar closure panels. The sash frame 10 includes an edge member 12 which, when the window is closed, is brought substantially into engagement with a corresponding edge member 22 of the external frame 20. The sash frame 10 is provided with any suitable form of handle 13 and/or conventional window stay (not shown), but for securing the sash frame in its closed position, a locking device in accordance with the invention is provided to act between the edge members 12 and 22.

The edge members may be of generally conventional design, and the precise design may vary; accordingly, in the accompanying drawings only the general shape of these edge members is indicated.

As can be seen more particularly from Figures 4a to 4c, the edge members 12 and 22 include respective webs 14 and 24 which face one another in spaced relation when the window is closed.

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Additionally, the edge member 12 of the sash frame includes an exterior flange 15 which extends to both sides of the web 14 and an interior flange 16 which extends predominantly 5 only on one side of the web, but includes a narrow extension 17 on the opposite side thereof. In known manner, a single, or double, glazed window pane 19 is mounted in the channel defined by the web 14 and flanges 15 and 16.

10 The edge member 22 of the external frame is of generally similar shape, and in addition to the web 24 includes an exterior flange 25 and an interior flange 26, both of which would normally extend to both sides of the web 24.

15 As can be seen, the space bounded by the webs 14 and 24 and the flanges 25 and 26 is utilised to accommodate and conceal a locking device which comprises two parts 30 and 40 secured respectively to the webs 14 and 24 of the sash 20 frame edge member 12 and the external frame edge member 22. In a typical case, the space available between the webs 14 and 24 is about 14 mm only, and it is an important feature of the present design that affords a mechanism which 25 can fit into such a restricted gap.

The part 30 of the locking device which is secured to the edge member 12 of the openable sash frame 10 comprises a mounting bar 31 which is secured to the web 14 in any convenient 30 manner. The bar 31 affords, in this particular case, two spaced catch formations which comprise shaped blocks 32, only one of which is shown in the accompanying drawings. It will be appreciated that, alternatively, similar catch formations could 35 be provided on, or formed integrally with, the web 14, so as to be built-in with the sash frame.

The part 40 of the locking device which is mounted on the edge member 22 of the external frame 20 comprises a locking mechanism which 40 includes a sliding bar 41 affording locking formations adapted to co-operate with those afforded by the other part 30 of the device. In this case, the locking formations comprise blocks 42 which are similar to the blocks 32 and designed to 45 co-operate therewith in the manner hereinafter explained. It will be appreciated that such blocks

42 could be replaced by corresponding locking formations formed integrally with the sliding bar 41.

50 In the illustrated embodiment, the sliding bar 41 is carried by a channel section guide member

43 which is itself secured to the web 24 in any suitable manner. It will be appreciated that, alternatively, the sliding bar 41 could be guided by

55 means of suitable formations integral with the web 24 itself.

One end of the sliding bar 41 is fixedly secured to a block-like body 44 which is formed with longitudinal grooves 45 which engage slidably 60 with edge portions 46 of the guide member 43 which thereby guide not only the sliding bar 41 but also the body 44. The body 44 includes an extension 47 formed with a longitudinal slot 48 which receives a pin 49 which is secured to the 65 web 24. The sliding bar 41 may be formed with similar slots at spaced intervals along its length for the reception of similar pins or other fastening elements, which may be of headed form, whereby the mechanism 40 is secured to the web 24.

The body 44 carries an operating element 50 which comprises a disc 51 rotatably located in the circular part 53 of a key-hole shaped recess 52 which also includes a divergent part 54 which opens into the longitudinal side of the block 44 which faces the flange 26 on the interior side of the edge member 22. The disc 51 is formed with a groove 55 which extends around most of its periphery, and a spring loaded detent member (not shown) engages therein to retain the disc in the circular part 53 of the recess 52.

The disc 51 is formed with a radial bore 56 between the ends of the groove 55 which is adapted to receive releasably one end of a lever

57 which can be inserted through an aperture 58 formed for this purpose in the flange 26 at the interior side of the edge member 22. The aperture

58 affords a bearing surface which serves a fulcrum for the lever 57. Thus, when the lever is inserted, as illustrated in Figure 2, and pivoted about such fulcrum, the body 44 and sliding bar 41 are caused to move under the constraint of the guide member 43 in a direction longitudinal of the edge member 22. The lateral sides 59 of the divergent part 54 of the recess 52 serve as abutments which co-operate with the lever 57 to limit the longitudinal movement of the bar 41 in both directions. Alternatively, such a limit may be imposed by the length of the slots, such as slot 48.

Whilst the operating element is preferably in the form of the disc 51, it would alternatively be possible for the disc to be omitted since the body 44 could be moved as necessary simply by direct engagement between the end of the lever 57 and the edges 59 of the divergent recess 54.

The blocks 42 on the slidable bar 41 are movable by means of the lever 57 between a releasing position in which (when the sash frame 10 is in its closed position relative to the external frame 20) they are disposed adjacent to, but clear of, the blocks 32 carried by the edge member 12 of the sash frame 10, and a locking position in which, as shown in Figures 2 and 4a to 4c, they engage the blocks 32 in such a manner as to prevent movement of the latter laterally in the window opening direction as indicated by arrow 60.

Preferably, as shown, the blocks 32 and 42 include respective oblique co-operating faces 32a and 42a so arranged that any attempt to force the sash frame 10 outwardly in the direction of arrow 60 will tend to transmit a force to the blocks 42 on the sliding bar 41 having a component in a direction which would tend to move the slidjng bar 41 in the locking direction rather than in the releasing direction.

The lever 57 may comprise a rod having a handle (not shown) at one end, and whilst the end which is received within the bore 56 may be of plain round or non-round section, alternatively the bore and the end of the rod may be screw-

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threaded so that the lever can be secured in assembled relation with the locking mechanism 40 if the window is required to be opened and closed relatively frequently, and removed when it 5 is required to ensure that the window is not opened. In the latter case, it would be possible to insert a grub screw or the like into the bore 56, of such a length that it extends into, but preferably not through, the aperture 58, thereby positively 10 holding the locking mechanism in its locking condition.

The aperture 58 may be temporarily plugged by a suitable cap member for additional security.

Instead of the fulcrum for the lever 57 being 15 afforded directly by the aperture 58, it could alternatively be afforded by a suitable bush inserted within such aperture, or by an aperture in, or bush carried by, a lug provided on the guide member 42 at a suitable position.

20 It will be observed that in Figure 1, where the locking device is installed at an upright edge of a window, the aperture 58 is disposed near to the bottom end of the frame, thus making the mechanism particularly easy to operate in view of 25 the convenient height of the operating element.

In a further arrangement, the removable lever 57 could be replaced by a pivotally mounted handle carried by the edge member on which the mechanism 40 is provided. In such a case the 30 handle may operate as a bell crank lever, having one long arm adapted to be gripped by the operator, and one short arm equivalent to the lever 37 which extends through the aperture 58 which may then be of suitably elongated form. The 35 handle will include a transverse pivot at the junction of the two arms, said pivot being engaged, removably if desired, by a mounting bracket secured to the edge member.

Whilst it is particularly convenient for the body 40 44 to be provided at one end of the sliding bar 41, where the mechanism is incorporated at the vertical edge of a window whereof the lower edge is spaced above the floor by a distance of the order of 1 m or more, it will be appreciated that 45 the body 44 could in a similar manner carry a further sliding bar at its opposite end, or be secured to the mid-portion of the sliding bar, particularly where the mechanism is to be installed at the vertical edge of a door or at an 50 horizontal edge of a long window.

As applied to an outwardly opening window, as illustrated in Figure 1, the locking mechanism 40 is most conveniently carried by the external frame. As applied to an inwardly opening window, it will 55 be appreciated that the locking mechanism 40 would most conveniently be applied to the inwardly opening sash frame. However, in both cases the opposite arrangement could be employed.

60 Whilst the complementary catch formations and locking formations are conveniently in the form of blocks 32 and 42, they could take other forms. Thus, as previously mentioned, suitable co-operating formations could be moulded integrally 65 with, or pressed-out from, the parts by which the blocks are carried. As a further alternative, such formations could comprise a pin which is receivable within a longitudinally extending slot having a lateral opening through which such pin can pass when aligned therewith. In a further arrangement as described more fully in relation to Figure 6, the formations could comprise a headed pin received within a longitudinal slot which has a locally widened portion through which the head of the pin may pass when suitably aligned.

Whilst in the accompanying drawings, the locking device is shown at the edge of a hinged window opposite to the hinged edge, it will be appreciated that the locking device could additionally, or alternatively, be provided at one or both edges adjacent to such hinged edge. However, the invention is not limited in its applicability to hinged structures. Thus, a completely removable panel could be releasably secured within a frame by means of at least two of such locking devices disposed at respective opposed edges.

Moreover, use of the locking device is not confined to securing an openable window to a fixed frame, it will be understood that whilst one part of the locking device will always be carried by an openable structure, the other part may be carried by a fixed frame (as illustrated) or by, for example, an adjacent fixed or openable window. Of course, where both windows are openable, a suitable locking mechanism (whether in accordance with the invention or not), would be provided to secure one of such windows to a surrounding frame.

The invention may also be applied to a sliding window to secure a sliding sash to a fixed frame, or to an adjacent fixed, or sliding, sash. One way in which this could be achieved is illustrated in Figure 5. This shows a sectional view, similar to Figure 4a, of an arrangement in which the locking mechanism 40, as previously described, is carried by an edge member 122 of a sash frame which is slidable in the direction of the arrow 101 away from an edge member 112 which may form part of a fixed external frame or an adjacent sliding sash, the edge 112 carrying the part 30 of the locking device as previously described.

A further arrangement suitable for use with sliding windows is illustrated in Figure 6 which again shows a transverse section similar to Figure 4a. In this case, a modified locking mechanism 140 includes a sliding bar which carries headed studs 142 which are engageable in corresponding longitudinal slots 132 formed in the web 114 (or a mounting plate secured thereto). The slots 132 are formed with widened portions 132a through which the head of the respective pin 142 may pass when suitably aligned. Either of the edge members, shown in section in Figure 6, may form part of an external frame, the other then carrying a glazing panel in conventional manner, or both of the edge members may form part of respective sliding sashes.

In all cases previously described, the locking

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mechanism is received within a shallow rebate in the external periphery of an opening sash, or the internal periphery of an external frame, in such a manner as to be concealed from view when in use.

5 The locking device may be formed separately so as to be capable of assembly with the edge members of existing window assemblies, or it may be incorporated directly into such assemblies. In the latter case it would be possible for the locking 10 mechanism 40 to be arranged on the side of the web remote from the edge member which carries the other part 30 of the device, said web being apertured as necessary to enable the blocks 42 or other locking formation to engage the catch 15 formations. In this way, the mechanism could be concealed internally of the edge member on which it is provided, but the slim dimensions of the mechanism enable it to be incorporated in this way in a narrower edge member than previously 20 known locking systems.

By providing a removable operating lever and a concealed locking mechanism, the invention affords a highly secure locking device which cannot readily be tampered with from the outside 25 by a potential intruder, even if the glazing panel is broken in an attempt to obtain access, since the location of the aperture for the operating lever cannot be determined by inspection from the outside, in contrast to many conventional security 30 locks which are easily visible through the glazing panel.

Accordingly, the invention is particularly suitable for use with glazed windows and doors, but it will be appreciated that it is also applicable 35 to non-glazed doors and the like closure panels.

Claims (29)

1. A door or window assembly of the kind comprising a door or window panel structure movable relative to a further structure between a 40 closed position and one or more open positions, said structures each including respective edge members which come substantially together in the closed position with facing parts thereof at least partially in spaced relation, wherein a locking 45 device for retaining said structures releasably in the closed position comprises one or more catch formations formed or provided on or adjacent to the facing part of the edge member of one of said structures, and a locking mechanism mounted on 50 or adjacent to the facing part of the edge member of the other of said structures, which mechanism comprises a movable element guided for movement longitudinally of the edge member and formed or provided with one or more co-operative 55 locking formations adapted to co-operate with said catch formations to prevent movement of said panel structure from the closed position, the movable element being formed or provided with an operating element which is engageable by a 60 lever having a fulcrum at a position offset from the longitudinal axis of the movable element in a direction transverse to the direction in which said facing parts are spaced when the structures are in said closed position.

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2. An assembly according to Claim 1 wherein the edge member of said other structure, on which the locking mechanism is mounted, includes a flange which extends transversely of said facing part and affords said fulcrum for the lever.

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3. An assembly according to Claim 2 wherein said fulcrum is afforded by an aperture in said flange.

4. An assembly according to any one of the preceding claims wherein the lever is detachably

75 associated with said operating member and said fulcrum.

5. An assembly according to Claim 1 wherein the lever is formed as a handle which is pivotally mounted on a bracket carried by said other

80 structure on which said mechanism is provided.

6. An assembly according to any one of the preceding claims wherein the operating element comprises an element mounted on said movable element for rotation about an axis which extends

85 transverse to the length of the movable element and transverse to the facing part of the edge member on which the movable element is mounted.

7. An assembly according to any one of Claims

90 1 to 5 wherein the operating element comprises an apertured portion of the movable element adapted to receive the end of said lever.

8. An assembly according to any one of the preceding claims wherein the movable element

95 extends over substantially the entire length of the edge member on which it is carried and affords a plurality of said locking formations at regular intervals, and an equivalent number of said catch formations are provided at similar spacings on an 100 elongated base member carried by the edge member of said one structure.

9. An assembly according to Claim 8 wherein the operating element is provided at one end of said movable element so that the movable

105 element can be formed by severing a single piece from a stock length of suitable material having said locking formations provided or integrally formed thereon.

10. An assembly according to any one of the 110 preceding claims wherein the movable element is mounted on a guide member which is formed or provided on said edge member.

11. An assembly according to any one of the preceding claims wherein said structures comprise

115 an external frame and a door or window hingedly connected thereto at one edge.

12. An assembly according to Claim 11 wherein said locking device is provided at an edge opposed to said hinged edge.

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13. An assembly according to Claim 11 or Claim 12 wherein said locking device is provided at one or more edges adjacent to said hinged edge.

14. An assembly according to any one of 125 Claims 11 to 13 wherein the locking device is provided at an in-use upright edge of a window assembly and the operating element is disposed at a position adjacent to the in-use bottom end of said upright edge.

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15. An assembly according to any one of Claims 1 to 10 wherein said structures comprise an external frame and a removable panel releasably secured in said frame by means of said

5 locking devices provided at respective opposed sides thereof.

16. An assembly according to any one of Claims 10 to 15 wherein said locking mechanism is mounted on said external frame.

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17. An assembly according to any one of

Claims 10 to 15 wherein said catch formations are provided on said external frame.

18. An assembly according to any one of Claims 1 to 9 wherein said structures comprise an

15 external frame and a door or window mounted for sliding movement in said frame.

19. An assembly according to any one of Claims 1 to 9 wherein said structures comprise two doors or windows mounted for sliding

20 movement relative to one another.

20. A door or window assembly comprising two structures which are relatively movable between one or more open positions and a closed position in which edge members of the two

25 structures are brought at least substantially into engagement, wherein said edge members in the closed position have facing parts thereof at least partially in spaced relation, and a locking device for securing the two structures releasably in the 30 closed position is concealed within a space defined between said facing parts, the locking device being operable by means of a lever which extends into said space through a flange which forms a lateral boundary of said space. 35

21. A door or window assembly for installation in an aperture formed for that purpose in a building, comprising an openable door or window structure and a further structure comprising a surrounding frame or a further door or window 40 structure which in either case includes an edge member forming part of the boundary of an opening which can be closed by the openable door or window structure, said openable structure having an edge member which is movable into 45 and out of contact with said edge member of the further structure, wherein one of said edge members carries a concealed locking mechanism having one or more locking formations adapted to co-operate with one or more corresponding catch 50 formations formed or provided on the other of said edge members, the mechanism being operable by means of a lever which extends through an aperture in the edge member which carries the mechanism, the lever then being pivotable about a 55 fulcrum afforded by said aperture or provided adjacent thereto.

22. In a domestic, industrial or commercial building including interior and/or exterior walls having openings provided for door and window 60 assemblies, a door or window assembly in at least one of said openings comprising an openable door or window structure having an edge member which is movable into and out of contact with an edge member of a further structure comprising a

65 surrounding frame or a further door or window structure which in either case includes an edge member forming part of the boundary of an opening which can be closed by the openable door or window structure, said openable structure 70 having an edge member which is movable into and out of contact with said edge member of the further structure, wherein one of said edge members carries a concealed locking mechanism having one or more locking formations adapted to 75 co-operate with one or more corresponding catch formations formed or provided on the other of said edge members, the mechanism being operable by means of a lever which extends through an aperture in the edge member which carries the 80 mechanism, the lever then being pivotable about a fulcrum afforded by said aperture or provided adjacent thereto.

23. A locking device for installation in a door or window assembly of the kind comprising two

85 structures which are relatively movable between one or more open positions and a closed position in which edge members of the two structures are brought at least substantially into engagement and have facing parts at least partially in spaced 90 relation, said device comprising one or more catch formations adapted to be mounted on or adjacent to the facing part of the edge member of one of said structures, and a locking mechanism adapted to be mounted on or adjacent to the facing part of 95 the edge member of the other of said structures, which mechanism comprises a movable element guided for movement longitudinally of the edge member and formed or provided with one or more co-operative locking formations adapted to

100 co-operate with said catch formations to prevent movement of said panel structure from the closed position, the movable element being formed or provided with an operating element which is engageable by a lever having a fulcrum at a

105 position offset from the longitudinal axis of the movable member in a direction transverse to the direction in which said facing parts are spaced when the structures are in said closed position.

24. A locking device substantially as

110 hereinbefore described with reference to and as shown in Figures 2, 3,4a, 4b and 4c of the accompanying drawings.

25. A locking device according to Claim 24 modified substantially as described with reference

115 to and as shown in Figure 6 of the accompanying drawings.

26. A door or window assembly incorporating a locking device provided on edge members thereof substantially as hereinbefore described with

120 reference to and as shown in Figures 2,3,4a, 4b and 4c of the accompanying drawings.

27. A door or window assembly incorporating a locking device provided on edge members thereof substantially as hereinbefore described with

125 reference to and as shown in Figure 5 of the accompanying drawings.

28. A door or window assembly incorporating a locking device provided on edge members thereof

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substantially as hereinbefore described with

29. A window assembly substantially as reference to and as shown in Figure 6 of the 5 hereinbefore described with reference to Figure 1

accompanying drawings. of the accompanying drawings.

Printed for Her Majesty's Stationery Office by the Courier Press, Leamington Spa, 1984. Published by the Patent Office, 25 Southampton Buildings, London, WC2A 1AY, from which copies may be obtained.