GB2462538A - Espagnolette mechanism - Google Patents

Abstract

An espagnolette mechanism 20 comprising a locking bolt member 28, 30, wherein movement between retracted and extended positions of the locking bolt involves rotary motion. The locking bolt 28 may be pivotally mounted for solely pivotal movement and locking bolt 30 may pivot about an axis which linearly moves. The locking bolt may include a pin sliding in a curved guide slot to constrain movement of the locking bolt (pin 104, slot 100, fig.13). The locking bolts may be driven between locking and unlocking positions by a rack and pinion assembly. Each keeper may include a lead in surface to guide initial entry of the locking bolt and may have multiple slots enabling a secure vent position. Locking bolts may be provided at multiple positions along the wing including the corner. In a further aspect an espagnolette mechanism comprises locking bolt which comprises a plurality of bolt portions (218a, 218c, fig.21) and a keep for receiving each bolt portion such that a plurality of parallel locking bolts may be provided each locatable in a separate keeper offset from each other.

Description

Espagnolettes The present invention relates to espagnolettes.

Examples of the present invention provide an espagnolette mechanism comprising: a bolt member having an advanced position and a retracted position; a coupling arrangement operable to cause the bolt member to be moved between the advanced and retracted positions by operation of the coupling arrangement; wherein movement of the bolt member between the advanced and 1 5 retracted positions includes a rotation.

The said rotation may be a pivotal movement. The said rotation of the bolt member may be solely pivotal.

The bolt member may have a fixed pivot axis around which the coupling arrangement pivots the bolt member to advance and retract. The coupling arrangement may include a linearly movable member coupled with the bolt member at a position offset from the fixed pivot axis.

The bolt member may pivot about an axis which moves while the bolt member is moving between the advanced and retracted positions. The pivot axis may move linearly. The bolt member may be constrained to pivot in a predetermined manner about the movable axis as the axis moves. The bolt member may be pivotally attached to a member driven by manipulation of the handle. The driven niember may extend, in use, along an edge of a window or door sash.

The pivotal movement of the bolt member may be constrained by a surface carried by the bolt member, and slideable across a fixed surface. The fixed surface may be a cam or track. The pivotal movement of the bolt member may be constrained by a pin spaced from the pivot axis and movable along a slot.

The pin may be carried by the bolt member and the slot may be provided in a fixed member.

The bolt member may comprise a plurality of bolt portions, the mechanism further comprising a keep for receiving each bolt portion. A first bolt portion may be formed to enter a first keep in advance of the entry of a second bolt portion into a second keep.

The mechanism may further comprise at least a third bolt portion, the first bolt portion entering the first keep in advance of the other bolt portions entering 1 5 respective keeps. The mechanism may be engageable in a first alignment with each bolt member engaged in a respective keep, and in at least one other alignment with at least one keep occupied by a different bolt member. The mechanism may have three bolt members arranged side by side, there being a second alignment in which at least one bolt member does not occupy a keep.

The three bolt members may be a middle bolt member and two side bolt members, there being a middle keep and two side keeps. The second alignment may have one side keep occupied by a side bolt member, the middle keep and the other side keep being unoccupied.

The mechanism may comprise two bolt members coupled as aforesaid. The bolt members may rotate in opposite senses as the mechanism is operated. The bolt members may be driven by respective members which are movable in different directions as the handle rotates.

The mechanism may be moUnted, in use, on an opening sash in a frame, the bolt member being located in the region of a corner of the frame and the coupling arrangement creating a linear element of movement toward and away from a first side of the frame, and a pivotal element of movement toward and away from a second side of the frame, the second side meeting the first side at the corner of the frame.

The mechanism may further comprise a keep member located at the corner to be received the bolt when advanced. The keep member may provide a plurality of keeps for receiving the bolt member. The keep or one of the keeps may have one or more lead-in surfaces engageable by the bolt member to create a predetermined alignment of the bolt member and the keep or keeps. The mechanism may further comprise a compressible seal member which is compressed as the predetermined alignment is reached. The keep may provide an outer face which extends diagonally across the corner and defines an opening to receive the bolt.

Bolt members as aforesaid may be provided at both ends of the second side.

The bolt members may be moved by a common coupling arrangement.

In another aspect, examples of the invention provide an espagnolette mechanism comprising: a bolt member having an advanced position and a retracted position; and a coupling arrangement operable to cause the bolt member to be moved between the advanced and retracted positions by operation of the coupling arrangement; wherein the bolt member comprises a plurality of bolt portions, the mechanism further comprising a keep for receiving each bolt portion.

A first bolt portion may be formed to enter a first keep in advance of the entry of a second bolt portion into a second keep. The first keep may have one or more lead-in surfaces engageable by the first bolt portion to create a predetermined alignment of the bolt member and keep or keeps, prior to the second bolt portion entering the second keep. The mechanism may further comprise a compressible seal member which is compressed as the predetermined alignment is reached.

The mechanism may further comprise at least a third bolt portion, the first bolt portion entering the first keep in advance of the other bolt portions entering respective keeps. The mechanism may be engageable in a first alignment with each bolt member engaged in a respective keep, and in at least one other alignment with at least one keep occupied by a different bolt member. The mechanism may have three bolt members arranged side by side, there being a second alignment in which at least one bolt member does not occupy a keep.

The three bolt members may be a middle bolt member and to side bolt members, there being a middle keep and to side keeps. The second alignment may have one side keep occupied by a side bolt member, the middle keep and the other side keep being unoccupied.

An espagnolette mechanism according to this aspect of the invention may incorporate any feature or combination of features of the first aspect of the invention.

Examples of the present invention will now be described in more detail, with reference to the accompanying drawings, in which: Fig. 1 is a schematic diagram of an opening window with espagnolette mechanism; Fig. 2 is an enlarged view of an example of an espagnolette mechanism of* the invention; Fig. 3 is a plan view of a centre keep for the mechanism of Fig. 2; Fig. 4 is a face view of a corner keep for the mechanism of Fig. 2; Fig. 5 illustrates the central region of the espagnolette mechanism, with a handle fitted; Fig. 6 is a section through a window, showing the espagnolette 1 0 mechanism and handle installed; Fig. 7 shows the gearbox and centre bolts of the espagnolette mechanism; Figs. 8 and 9 are plan and side views of the centre bolts, on an enlarged scale; Figs. lOa to lOd illustrate the gearbox mechanism and centre bolts, and Fig. 11 is an exploded view of the gearbox; Fig. 12 corresponds with Fig. 7, in the locked conditibn; Figs. 13 and 14 illustrate the corner bolt arrangements, respectively unlocked and locked; Fig. 15 illustrates the location of the corner bolts when installed in a window; Fig. 16 is a set of views of a corner bolt; Fig. 17 is a view at the line 17-17 of Fig. 13; Figs. 18 and 19 are perspective views of a second alternative; Figs. 20 and 21 are elevations of the second alternative; Fig. 22 is a section of the second alternative; Figs. 23 to 25 are respectively perspective, elevation and end elevation views of the second arrangement in the night vent condition; Figs. 26 to 28 are respectively a side elevation, partial section and perspective view of a third example in the unlocked condition; and Figs. 29 to 31 correspond with Figs. 26 to 28, showing the locked position.

Overview Figure 1 illustrates a window 10 having a fixed outer frame 12 and an opening sash 14. In this example, the sash 14 opens about a generally horizontal axis at its upper edge, indicated by the lines 16. A handle 18 is provided at the lower edge of the sash 14 for opening and closing the window.

The handle 18 can be manipulated to operate an espagnolette mechanism 20, the location of which is schematically indicated in figure 1. The espagnolette mechanism 20 provides locking engagement between the sash 14 and the frame 12, at various positions along the lower edge of the sash 14, to improve the security of the window 10.

The skilled reader will readily appreciate that the espagnolette mechanism being described can also be installed along a vertical edge of a window which o5ens about a vertical axis, or can be used in conjunction with a door and door frame.

Figure 2 illustrates the principal components of a first example espagnolette mechanism 20. The sash 14 carries the main mechanism, including a coupling arrangement 22 having a gearbox 24 arid adjustable extending rods 26. Two centre bolts 28 and two corner bolts 30 are driven by the coupling arrangement 22.

The centre bolts 28 have an advanced position and a retracted position and are illustrated in figure 2 in their retracted position. When advanced, the 1 0 centre bolts 28 engage with a keep 32 (Figure 3) to assist in locking the sash 14 to the frame 12. Movement of the centre bolts 28 between the advanced position and the retracted position includes a pivotal movement.

The corner bolts 30 also have an advanced position and a retracted 1 5 position. When advanced, the corner bolts 30 engage with respective keeps 34 (Figure 4) to assist in locking the sash 14 to the frame 12. Movement of the corner bolts 30 between the advanced position and the retracted position includes a pivotal movement, as will be described.

An operating handle (shown only in Figure 1) is normally mounted on the gearbox 24, with a spindle in the square aperture 36. Manipulation of the handle to turn the spindle results in movement of the gearbox, which is transmitted through the coupling arrangement 22 to advance or retract the bolts 28, 30.

Accordingly, all four bolts 28, 30 can be advanced or retracted together. Thus, in this example, the sash 14 can be locked at four positions, by a single action of the handle.

Centre bolt arrangements and gearbox Turning particularly to Figures 5, 6 and 7, there is shown a handle 38 which has a base 40 and a grip 42. A spindle 44 is also visible in Figure 5. The grip 42 is pivotally mounted on the base 40 about the axis of the spindle 44, and connected to the spindle 44 so that the grip 42 can be turned relative to the base in order to turn the spindle 44. The spindle is square and, in use, fits in the aperture 46.

In addition to the aperture 36, the gearbox 24 has two circular through apertures 46. Each receives a fixing bolt 48 from the base 40. The fixing bolts 48 pass through the apertures 46 to secure the gearbox 24 in the sash extrusion, as can be seen from Figure 6. Accordingly, the bolts 48 simultaneously mount 1 0 the handle 38 on the sash 14 and secure the gearbox 24 within the sash extrusion 14.

Figures 8 and 9 show one of the centre bolts 28. The bolt is generally platelike in form, and has a pivot aperture 50 and an upstanding lug 52. The 1 5 edge of the bolt 28, furthest from the pivot aperture 50, has a circumferential, out-turned blade portion 54, centred at the centre of the aperture 50.

Returning to Figure 7, the position of the centre bolts 28 within the gearbox 24 can be seen. It is apparent that the pivot apertures 50 are centred at the through apertures 46. Accordingly, the bolts 48 penetrate the pivot apertures 50, when fixing the handle 38 and gearbox 24 to the sash 14. This provides a pivot for the bolts 28, about the bolts 48. Accordingly, the centre bolts 28 are moved by a solely pivotal movement, about the fixing bolts 48. The fixing bolts 48 define the pivot axis of each of the centre bolts 28.

The mechanism within the gearbox 24, for coupling the centre bolts 28 to the handle 38, can be described in more detail with reference to Figures 10 and * 11. Many other arrangements could be provided within the gearbox 24. The four views in Figure 10 show different levels within the gearbox 24, by removing varIous components, as will be described. The various iayers illustrated in Figure can be further appreciated by considering the exploded.view of Figure 11.

Figure 10 a shows a base plate 56 of the gearbox 24. The through apertures 46 are visible. A toothed gear 58 has a square aperture 60 aligned with the square aperture 36, described above, and is in mesh with two intermediate gears 62. The gears 62 also mesh with a rack 64 formed on a first slider 66. Accordingly, rotation of the gear 58 about the centre of the aperture 60 results in the gears 62 turning in the opposite direction to act as pinions on the rack 64, thereby causing the first slider 66 to slide in the direction of the double headed arrow 68, according to the sense in which the gear58 is rotated.

The first slider has a slot 70, the significance of which will become apparent.

The two centre bolts 28 are placed on the structure of Figure 10 a, to form the structure illustrated in Figure 10 b. Toward the left of the gearbox (as illustrated in Figure 10), one of the centre bolts 28 is placed with the lug 52 projecting towards the first slider 66, where the lug 52 will be received in the slot 70, just described. Noting that the centre bolt 28 is constrained to pivot around the through aperture 46, sliding movement of the first slider 66 will therefore cause the lug 52 to slide in the slot 70 and drive the centre bolt 28 to turn around the through aperture 46.

A similar arrangement drives the other centre bolt 28, illustrated to the right in Figure 10. This bolt 28 is inverted as compared with the first bolt described above, so that the corresponding lug 52 faces the viewer. This is received in a slot 72 in a second slider 74. The second slider 74 has a rack 76 which meshes directly with the toothed gear 58. Turning the gear 58 around the centre of the aperture 36 causes the gear 58 to act as a pinion to drive the rack 76 and thus to slide the slider 74. This causes the second slider 74 to slide in the direction of the double headed arrow 82, according to the sense in which the gear 78 is rotated.

The gearbox 24 is capped by a cover 78.

The square spindle 44 of the handle 38 is received in the square aperture 36, as has been described above, and therefore penetrates the square aperture of the gear 58. Accordingly, manipulation of the handle 38 to turn the spindle 44 results in the gears 58, 78 turning to slide the sliders 66, 74. As they slide, the sliders 66, 64 turn the centre bolts 28 around the through apertures 46, thus pivoting the centre bolts 28 between their advanced and retracted positions.

It can be seen from the above description that in each case, a gear arrangement couples the handle 38 to the corresponding centre bolt 28 and that each coupling arrangement comprises a rack and opinion arrangement. Thus, each rack 64, 76 is linearly movable by manipulation of the handle 38, to drive pivotal movement of the bolt member 28. This arises because the rack 64, 76 and the bolt member 28 is, in each case, connected by an arrangement which includes a slot 70, 72 and a lug 52 or pin, which is slidable in the slot 70, 72 as the rack 64, 76 moves and the centre bolt 28 pivots. In the case of the second slider, the gear 58 rotates about the pivot axis of the spindle 44, which is the same as the pivot axis of the handle 38, and thus the gear 78 acts as the pinion for the rack 76. In the case of the first slider 66, the gears 62 serve as pinions for the rack 64 and are mounted to rotate about respective pivot axes which are spaced from the pivot axis of the handle 38 and spindle 44. However, by virtue of the engagement between the pinion gears 62 and the gear 58, which is an element carried by the handle 38 as the handle 38 rotates, the pinion gears 62 and the handle spindle 44 are caused to rotate in opposite directions.

Accordingly, the first and second sliders 66, 74 are driven in opposite directions.

Furthermore, the centre bolts 28 swing in opposite senses, either swinging together as indicated by the arrows in Figure 7, from their retracted position (shovn there), or swinging back from their advanced position illustrated in Figure 12, in the direction indicated by the arrows in Figure 12.

Returning now to Figure 3, the centre keep 32 can be seen to have two T-shaped slots 84. As the centre bolts 28 swing from the retracted position (Figure 7) the blades 54 of the bolts 28 are received in the relatively wide regions of the 1-shaped slots 84 and the central plate regions 82 of the bolts 28 are received in the relatively narrow regions of the T-shaped slots 84. Once the centre bolts 28 have reached their advanced position (Figure 12), the blades 54 engage under the narrow regions of the slots 84 to secure the bolts 28 in the keep 32. This provides secure locking at the two positions of the bolts 28, securing the sash 14 to the frame 12 in the region of the gearbox 24. Furthermore, the robustness of this locking is considered to be enhanced by mounting the bolts 28 on the bolts 48, which are expected to be robust in order to prevent the handle 38 being forcibly removed.

1 5 Corner bolt arrangements (1) The coupling arrangement 22 includes rods 26, as has been described, which extend along the edge of the sash 14. The length of the rods 26 is adjustable by means of a mechanism which does not form part of the present invention, but allows the espagnolette mechanism 20 to be versatile for fitting to a range of different sizes of window or door. That is, the distance between the gearbox 24 and the corner bolts 30 can be adjusted to suit various different sizes of window or door.

The rods 26 are driven by the gearbox 24 to move in opposite directions.

That is, the rods 26 either move in opposite directions away from the gearbox 24, or withdraw in opposite directions toward the gearbox 24, when a handle is used to operate the gearbox. The arrangements at the remote ends of the rods 26 cOrrespond with each other and consequently, only ore end need be described in detail, for a full understanding to be obtained. The end of one of the rods 26 is illustrated in more detail in Figures 13 to 15.

The end of the rod 26 is in the form of a carriage 88 which runs along a track 90 providing a base for the mechanism 20. The track 90 is secured to the sash 14 by fixing screws or bolts 91. The carriage 88 ends in two side limbs 92.

The corner bolt 30 is partly received between upstanding walls 93 of the track 90.

The walls 93 are themselves located between the limbs 92: The corner bolt 30 is shown in more detail in Figure 16. The bolt 30 is formed from sheet material, 1 0 such as metal, folded to the form shown. This defines a main portion 94 and an arm 96. Two apertures 98, 100 are formed through the arm 96 of the bolt 30.

The aperture 98 receives a pivot pin 102. The other aperture 100 receives a pin 104. The pin 102 passes through the walls 93 and is secured to the limbs 92 to provide a pivot connection between the bolt 30 and the limbs 92 of the carriage 88. The pin 104 is free to run along a curved slot 106 in each of the walls 93.

The slots 106 may have straight extensions (not visible in Figure 17) to receive the pin 102. The pivotal movement of the bolt 30 is thus constrained by the engagement of the pin 104 and slots 106, and the spacing of the pin 104 from the pivot axis 102. Accordingly, as the carriage 88 (and thus the pivot pin 102) is driven by manipulation of the handle 38 to move linearly, the curve of the slots 106 causes the bolt 30 to pivot about the pivot pin 102. The bolt 30 pivots about an axis 102 which moves while the bolt member 30 is moving between the advanced and retracted positions. The coupling arrangement 22 acts on the bolt to create a linear element of movement toward and away from a side 108 of the frame 12, and a pivotal element of movement toward and away from the base of the frame 12. This causes the bolt 30 to extend out into the corner 112 of the frame 12, where the side 108 meets the base 110.

A corner keep 34 is provided in this corner 112. The keep 34 is a metal strip robustly secured at its ends to the side 108 and base 110 by means of appropriate fixings, such as screws or bolts 116. Other materials can be used for the keep 34. The keep 34 provides an outer face which extends diagonally across the corner 112. The keep 34 has a slot positioned to receive the bolt 30 when it advances.

When the carriage 88 is fully withdrawn (Figure 13), the bolt 30 is in its retracted position, with the pin 104 near the top end of the slots 106. When the carriage 88 is advanced toward the side 108, the pin 104 is pushed along the slot 106, which causes the bolt 30 to pivot down into the keep 34 until the advanced position of Figure 14 is reached.

It is apparent from a comparison of Figure 13 and Figure 14 that a relatively small movement of the carriage 88 results in deep penetration of the bolt 30 into the keep 34. It is also apparent from Figure 14 that the main portion 94 of the bolt 30 is wide where it penetrates the keep 34. Accordingly, a robust 1 5 locking action is created in the corner 112. A corresponding robust locking action is created in the corner at the other end of the mechanism 20, by the other bolt 30. This is achieved without requiring the bolt 30 to penetrate the extruded profile of the frame 12.

In this example, the interaction of the pin 104 and the slots 106 serves to constrain the bolt 30 to pivot in a predetermined manner about the moveable axis of the pivot pin 102, as the axis moves. The manner of pivoting is predetermined by the shape of the slots. The boundaries of the slots 106 provide fixed surfaces across which the pin 104 is constrained by the boundaries of the slots 106. Other arrangements are possible for creating a predetermined manner of pivoting. For example, a camming action could be provided between a surface of the bolt 30, and another surface. The bolt 30 could move along a track as it turns.

Corner bolt arrangement (2) Figures 18 to 25 illustrate an alternative corner bolt arrangement 210.

This can be driven by a coupling arrangement similar to that described above and therefore reference numerals are used again, where appropriate.

Thus, the coupling arrangement 22 includes rods 26, as has been described, which extend along the edge of the sash 14. The length of the rods 26 is adjustable by means of a mechanism which does not form part of the present invention, but allows the espagnolette mechanism 20 to be versatile for fitting to a range of different sizes of window or door. That is, the distance between the gearbox 24 and the corner bolt arrangements 210 can be adjusted to suit various different sizes of window or door.

The rods 26 are driven by the gearbox 24 to move in opposite directions.

That is, the rods 26 either move in opposite directions away from the gearbox 24, or withdraw in opposite directions toward the gearbox 24, when a handle is used to operate the gearbox. The arrangements at the remote ends of the rods 26 correspond with each other and consequently, only one end need be described in detail, for a full understanding to be obtained. The end of one of the rods 26 is illustrated in more detail in the Figures 18 to 25.

The end of each rod 26 carries a carriage 212 which runs along a track 214 secured, in use, to the sash 14 by fixing screws or bolts at 91. The carriage 212 is located in a corner region of the sash 14 and frame 12, where a keep member 216 is fixed to the frame 12. A bolt member 218 is provided for engaging the keep member 216, as will be described.

An L-shaped extension arm 220 has a limb which runs perpendicular from the track 214 at the corner of The sash 14. The other limb of the extension arm 220 is fixed to the track 214, forming a fixed right angle arrangement. The extension arm 220 provides a fixed pivot axis for the bolt member 218 at a pivot pin 222, around which the bolt member 218 is pivoted by the action of the coupling arrangement 22. This pivot action causes the bolt member 218 to advance and retract.

The bolt member 218 comprises a plurality of bolt portions 218a,b,c, and the keep member 216 provides a respective keep 216a,b,c to receive each bolt portion. The bolt portions 218a,b,c are in the form of three planar leaves, arranged side-by-side in a parallel arrangement. The leaves form a middle bolt portion 280 a, and two side bolt portions 218b and 218c. All three leaves pivot together around the pivot pin 222.

The keep member 216 provides three keep recesses, namely a middle keep 216a and two side keeps 216b,c.

A second pin 224 extends parallel to the pivot pin 222 to couple the bolt member 218 to the carriage 212 at a position offset from the fixed pivot axis provided by the pivot pin 222. The pin 224 passes through short upright slots 226 in each flank of the carriage 212 (see Figure 22), and through curved slots 227 in the extension arm 220. The curved slots 227 are centred at the pivot pin 222. Consequently, linear movement of the rod 26 toward and away from the gearbox 24 pushes or pulls the bolt member 218 to swing the bolt member between the retracted position (Figures 18 and 21) and the advanced position (Figures 19, 20 and 22 to 25). In the advanced position, the bolt member 218 engages the keep member 216, as will be described.

The keep member 216 is significantly cut back in the vicinity of the mouths of the side keeps 216b,c. The consequence of this isthat the middle bolt portion 218a will swing into the middle keep recess 21 6a in advance of the entry of either of the side bolt portions 218b,c into the correspondin keep recess 216b,c.

Furthermore, the first keep recess 216a has lead in surfaces 228 at the mouth.

These are engageable by the first bolt portion 218a to encourage a predetermined alignment of the bolt member 218 with the keep member 216.

Thus, if the bolt member 218 is out of this predetermined alignment as the middle bolt portion 218a reaches the mouth of the middle keep recess 216 a, interaction between the bolt portion 218a and the surfaces 228 will pull the bolt member 218 into the predetermined alignment. This, in turn, pulls the sash 14 to a predetermined position relative to the frame 12. This may have the effect of creating compression in a compressible seal illustrated schematically at 230. As has been noted above, the middle bolt portion 218a engages the keep member 216, and therefore creates the required alignment, before the side bolt portions 218b,c engage the keep member 216. This ensures that the side bolt portions 21 8b,c are correctly aligned for their respective keep recesses before they enter.

They then provide additional locking security. Once the bolt member 218 is fully home in the keep member 216, three point locking is achieved.

The above description explains how the bolt member 218 is used to provide locking when the sash 14 is to be locked in its fully closed position in the frame 12. Another locking alignment is possible, as follows. In this alternative locking alignment, one of the keep recesses is occupied by a different bolt portion.

In this alternative, one of the side bolt portions 218b is received in the other side keep recess 216c (as compared with the fully closed position). The middle bolt portion 218a and the other side bolt portion 218c miss the keep member 216 and remain exposed, as can be seen from the drawings. In order to attain this alignment, the gearbox 24 and rods 26 are operated as described above, to swing the bolt member 218 over to the advanced position, but with the * sash 14 aligned with the frame 12 so that the side bolt portion 218b enters the side keep recess 216c. This has the effect of locking the sash 14 in a slightly ajar position and in particular, the seals 230 will not be effective. Accordingly, this condition can be used as a night vent position. Even in the night vent position, the window or door remains secure by virtue of the locking provided in both corners of the sash 14, by the two bolt members 218.

Corner bolt arrangement (3) Figures 26 to 28 illustrate a further alternative corner bolt arrangement 250. This can be driven by a coupling arrangement similar to that described above and therefore reference numerals are used again, where appropriate.

Thus, the coupling arrangement 22 includes rods 26, as has been described, which extend along the edge of the sash 14. The length of the rods 26 is adjustable by means of a mechanism which does not form part of the present invention, but allows the espagnolette mechanism to be versatile for fitting to a range of different sizes of window or door. That is, the distance between the gearbox 24 and the corner bolt arrangements 250 can be adjusted to Suit various different sizes of window or door.

The rods 26 are driven by the gearbox 24 to move in opposite directions.

That is, the rods 26 either move in opposite directions away from the gearbox 24, or withdraw in opposite directions toward the gearbox 24, when a handle is used to operate the gearbox. The arrangements at the remote ends of the rods 26 correspond with each other and consequently, only one end need be described in detail, for a full understanding to be obtained. The end of one of the rods 26 is indicated schematically in Figures 26 to 31.

The end of each rod 26 carries a carriage 252 which runs along a track 254 secured, in use, to the sash 14 by fixing screws or bolts at 255. The carriage 252 is located in a corner region of the sash 14 and frame 12, where a keep member 256 is fixed to the frame 12. A bolt member 258 is provided for engaging the keep member 256, as will be described.

An L-shaped extension arm 260 has a limb which runs perpendicular from the track 254 at the corner of the sash 14. The other limb of the extension arm 260 is fixed to the track 254, forming a fixed right angle arrangement. The extension arm 260 provides a fixed pivot axis for the bolt member 258 at a pivot pin 262, around which the bolt member 258 is pivoted by the action of the coupling arrangement 22. This pivot action causes the bolt member 258 to advance and retract.

The keep member 256 provides two respective keeps 256 a,b in which the bolt member 258 can be selectively received. The bolt member 258 has peripheral flanges 263 which project sideways from the bolt member 258, parallel to the axis of the pivot pin 262.

A second pin 264 extends parallel to the pivot pin 262 to couple the bolt 1 5 member 258 to the carriage 252 at a position offset from the fixed pivot axis provided by the pivot pin 262. The pin 264 passes through short slots 266 in the bolt 258 (see Figures 27 and 30), and through long slots 267 (see Figure 30) in the extension arm 260. The short slots 266 are radial from the pivot pin 262.

Consequently, linear movement of the rod 26 toward and away from the gearbox 24 pushes or pulls the bolt member 258 to swing the bolt member between the retracted position (Figures 26, 27 and 28) and the advanced position (Figures 29, and 31). In the advanced position, the bolt member 258 engages the keep member 216, as will be described.

The keep 256a corresponds with the fully closed position of the sash 14, so that the bolt member can be locked in its fully closed position in the frame 12.

Another locking alignment is possible, with the bolt member 258 in the other keep 256b. Thus, in this alternative locking alignment, the keep is received by a different keep recess. This has the effect of locking the sash 14 in a slightly ajar position and ii particular, seals (not shown) will not be effective. Accordingly, this condition can be used as a night vent position. Even in the night vent position, the window or door remains secure by virtue of the locking provided in both corners of the sash 14, by two bolt members 258.

In this example, security is enhanced by the presence of the flanges 263 on the bolt member 258. When the bolt member 258 is advanced into either of the keeps 256a, 256b, the flanges 263 move down behind the plane of the keep 256. This can be seen in Figure 31, for example. The flanges 263 prevent the bolt 258 being pulled out of the keep 256a, 256b in a direction parallel with the rods 26. If an attempt is made to pull the bolt 258 out of the keep in this 1 0 direction, for example in an attempt to force the window open by an intruder, the flanges 263 will engage behind the key 256, so that the lock cannot be released merely by distorting the frame or sash, but only by breaking one or more components.

Lead in surfaces can be provided for the keeps 256a, 256b, in similar manner as described above.

Concludinci comments The example mechanisms which have been described above, result in a robust locking action being achieved at four positions along the edge of the sash 14, by manipulation of a single handle, and also allow a secure night vent function. Bolts similar to the corner bolts described, and coupled in a similar manner, could be located at positions intermediate the corners and the gearbox, either instead of or in addition to corner bolts.

Many variations modifications can be made to the apparatus described above, without departing from the scope of the present invention. In particular, many different materials, combinatidns of materials, dimensions, relative dimensions, shapes and forms could be devised in order to implement the invention set out above.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.