GB2376712A

GB2376712A - Closure mechanism with surface features on a bolt and a keeper to impede withdrawal of the bolt from the keeper

Info

Publication number: GB2376712A
Application number: GB0114858A
Authority: GB
Inventors: Giovanni Maria Laporta
Original assignee: Giovanni Laporta
Current assignee: Giovanni Laporta
Priority date: 2001-06-18
Filing date: 2001-06-18
Publication date: 2002-12-24
Anticipated expiration: 2021-06-18
Also published as: GB2376712B; GB0114858D0; WO2002103142A1

Abstract

A closure mechanism comprises a shoot bolt mechanism which has at least one shoot bolt 102, 122, 142 operable to engage respective receiving keeps 106, 126, 146, in a frame when a leaf is shut in the closed position, wherein at least one shoot bolt has a first surface feature 104, 124, 144 that will engage a second surface feature 108, 128, 148 formed within the respective receiving keep(s) should any attempt 114, 134, 154 be made to force the leaf away from the frame when the leaf is closed. Such an attempt causes the first and second surface features to positively interact in order to impede the tendency of the shoot bolt(s) to withdraw from their respective receiving keep(s). The closure mechanism is for use in a window or door system which comprises a frame incorporating at least one receiving keep. The frame is pivotally coupled to a leaf, e.g. a window or door, by at least one hinge that permits movement of the leaf relative to the frame between closed and open positions. The leaf incorporates the closure mechanism for retaining the leaf in the closed position with respect to the frame. The closure mechanism may form part of an espagnolette mechanism [e.g. that shown in figures 2-4].

Description

CLOSURE MECHANISM The present invention relates to closure mechanisms. In particular, but not exclusively, it relates to closure mechanisms for use in window or door assemblies.

There are many types of closure mechanisms for windows and doors in existence, and these have evolved over time as new materials have become available and security requirements have become more demanding. For example, it is known in the art to provide locks, latches and espagnolette mechanisms to enhance security. It is also known that use of shoot bolts further improves security. Recently, improved developments have lead to a combination mechanism incorporating both shoot bolt and espagnolette mechanisms in an inexpensive and flexible manner.

One particularly advantageous locking system combines both a shoot bolt and espagnolette mechanism. However, although this type of locking system provides numerous advantages, particularly in terms of manufacturing costs and ease of fitting, extensive testing of such systems has revealed certain areas in which security could be improved. In particular, it has been found that when an external force (such as might be applied by an intruder) is applied to the sash, the shoot bolt end's natural movement will tend to cause it to slide out of a respective receiving keep, a phenomenon known as"riding out"."Riding out"is thought to be caused by numerous factors, either alone or in combination, such as: deformation of the sash; failure, disengagement or distortion of the shoot bolt connecting arms that connect to the handle gearbox; or rotation of the handle to an open position under the applied force.

The problem of"riding out"is particularly acute for combination systems of the type mentioned above, particularly when non-latching or non-locking handles are used. Moreover, where u-PVC is used to form the frame and/or part of the window or door sash, the natural flexibility of the u-PVC material co-operates with the closure mechanism to encourage the shoot bolts to retract from their keeps, and for the window or door to"pop"open.

Therefore, it is an objective of the present invention to mitigate one or more of the previously described problems associated with window or door systems employing shoot bolt mechanisms.

According to a first aspect of the present invention, there is provided a window or door system comprising: a frame for mounting in a window or door aperture, the frame incorporating at least one receiving keep : a leaf pivotally coupled to the frame by at least one hinge, wherein the leaf is moveable relative to the frame between closed and open positions; and a closure mechanism mounted to the leaf for retaining the leaf in the closed position, the closure mechanism comprising: a shoot bolt mechanism further comprising at least one shoot bolt operable to engage a respective receiving keep when the leaf is in the closed position, wherein said at least one shoot bolt has a first surface feature shaped so as to engage a second surface feature formed within the respective receiving keep responsive to an external force being applied to the leaf when in the closed position, wherein any engagement of the first and second surface features is such as to impede withdrawal of the at least one shoot bolt from the respective receiving keep.

By providing co-operating first and second surface features that only mutually engage should the window or door be forced, no increased friction is produced during operation of the closure mechanism. The extra security features afforded thus lay dormant, and unnoticed by the ordinary user, until they are most needed. Advantageously from the supplier's point of view, inexpensive and relatively minor modifications to standard "off-the-shelf'shoot bolt mechanisms and receiving keeps are all that is needed to implement the claimed subject matter.

The window or door system may further comprise an espagnolette mechanism operatively connected to the shoot bolt mechanism. Where this is the case, the action by which withdrawal of shoot bolts from receiving keeps is impeded also reduces the force that is concentrated at the coupling between the espagnolette and shoot bolt mechanisms. Since it is known that the coupling is particularly prone to disengagement, distortion or failure (particularly where such a coupling is of the adjustable type), this redistribution of force within the window or door system is particularly advantageous. u-PVC material may be used to form at least part of one or more of the frame and the leaf. Such material is known to be prone to flexing. By supporting a sash frame made from u-PVC material at multiple positions spaced about the periphery of such a sash, the force applied to the sash by a would-be intruder is distributed about

the window or door frame. This reduces the flexing of the sash and makes forced entry more difficult.

The window or door system may incorporate a closure mechanism of the nonlatching type. It may incorporate a non-latching handle mechanism. Such a handle arrangement is not uncommon in window systems, particularly for smaller windows, as it permits use of a less expensive and less complex closure mechanisms that may not physically fit within the sash. However, it is known that non-latching handles suffer from certain disadvantages. In particular, such handles are prone to rotate towards an open position when an external force is applied to any shoot bolts that are connected to them. So, by providing a mechanism for restricting the movement of the shoot bolts from respective keeps when a window sash is forced, additional security is provided even when non-latching closure mechanisms are used.

The window or door system may be provided with first and second surface features that are mutually co-operating chamfered surfaces. In another example, the first surface feature may comprise a notch and the second surface feature a protrusion.

In yet another example, the first surface feature may comprise a groove and the second surface feature a ridge. Preferably, the groove and ridge extend around the periphery of the shoot bolt and the keep aperture, respectively. This allows the groove and the ridge to engage should the shoot bolt move laterally in any direction, and further facilitates manufacture of the surface features. However, it is noted that any suitable co-operating features or surfaces may be used.

According to another aspect of the invention. there is provided a closure mechanism for mounting to a window or door leaf for retaining the leaf in a closed position, the closure mechanism comprising: a shoot bolt mechanism comprising at least one shoot bolt for engaging at least one receiving keep when the leaf is in the closed position, wherein at least one said shoot bolt has a first surface feature for engaging a second surface feature formed within a respective receiving keep responsive to an external force being applied to the leaf when in the closed position in order to impede withdrawal of the at least one shoot bolt from the respective receiving keep.

The closure mechanism may further comprise an espagnolette mechanism operatively connected to the shoot bolt mechanism and/or a non-latching handle

mechanism. The first surface feature may comprise one or more of : a chamfered surface; a notch and/or a groove.

According to another aspect of the invention, there is provided a window or door locking system which comprises an espagnolette locking mechanism, a first locking bolt driven by the espagnolette mechanism and moveable in the same direction as the locking movement of the espagnolette mechanism, and a second locking bolt driven by the espagnolette mechanism and moveable in an opposite direction to the locking movement of the espagnolette mechanism, wherein the first and second locking bolts have respective first surface features for engaging respective second surface features formed within respective receiving keeps responsive to an external force being applied to the window or door when in the closed position in order to impede withdrawal of the locking bolts from the respective receiving keeps.

The window or door locking system may comprise a first bolt unit carrying the first bolt, a second bolt unit carrying the second bolt, and a counter movement generator for moving the second locking bolt in an opposite direction to the locking movement of the espagnolette. The second bolt unit may comprise the counter movement generator. The window or door locking system may comprise a first rack and a second rack operatively coupled by at least one gear to produce a counter movement. At least one of the locking bolts of the window or door locking system may be coupled directly or indirectly to the espagnolette mechanism by way of complementary mating surfaces.

According to another aspect of the invention, there is provided a receiving keep suitable for engaging with a closure mechanism constructed according to any aspect of the invention.

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings where like numerals refer to like parts and in which: Figure 1 is a shoot bolt system according to the prior art; Figure 2 is a schematic drawing showing in exploded form the components of a combined shoot bolt and espagnolette system according to the prior art; Figure 3 is a rear view of the system of Figure 2;

Figure 4 is a front view of the system of Figure 2; Figure 5 shows an engagement portion of a shoot bolt mechanism constructed according to a first embodiment of the present invention; Figure 6 shows an engagement portion of a shoot bolt mechanism constructed according to a second embodiment of the present invention; and Figure 7 shows an engagement portion of a shoot bolt mechanism constructed according to a third embodiment of the present invention.

Figure 1 shows a prior art shoot bolt system. The shoot bolt includes two oppositely extending locking bolts 22 and 24 located at the comers of a window sash carrying the handle 26. The bolts 22 and 24 are moveable to engage with a respective keep 20, only one of which is shown in Figure 1 for clarity. A handle gearbox mechanism 30 includes two integral arms 28 and drives the arms in opposite directions from movement of the handle 26. The arms 28 are coupled to the bolts 22 and 24, to drive the bolts in opposite directions, between a locking position in which the bolts 22 and 24 project from the opposite edges of the sash, and a non-locking position in which the bolts 22 and 24 are retracted into the sash. The bolts 22 and 24 engage with the smooth bore of respective keeps 20 when the window is in the closed position. Additionally, the keeps 20 comprise mounting channels 18 for fixing to the window frame using screws.

Figures 2 to 4 show an espagnolette mechanism 42 including first and second bobbins 48 mounted on a slider 50 carried behind a face plate 52. The slider 50 is captively mounted by two mushroom lugs 54 received in slots 56 in the slider 50. The slider 50 is driven by a handle mechanism 58, which maybe a cam, or rack, or lever driven to convert rotational handle movement to linear slider movement. The slider 50 is moveable between a non-locking position (in which the handle is generally perpendicular to the slider 50) and a locking position (in which the handle lies generally parallel with the slider 50). Movement of the handle from the non-locking position to the locking position (as indicated by arrow 60) drives the slider 50 in the direction of arrow 62, and opposite movement of the handle drives the slider in the opposite direction. In contrast to a conventional espagnolette mechanism, the end

portions of the slider are formed with serrated edges 64 to permit simple attachment of the bolt units 44 and 46.

The first bolt unit 44 comprises an L-shaped corner mounting member 66 which supports a locking bolt 68 mounted on an angled driving arm 70. The driving arm 70 consists of a slider portion 72 which is captively mounted on the L-shaped member 66 by means of mushroom studs 74 received in elongate slots 76 to permit sliding movement of the bolt 68. The arm 70 also includes a bifurcated linking portion 78 carrying a serrated socket 80 engageable with the serrated end portion of the espagnolette slider 50. In use, the locking bolt of the first bolt unit 44 is driven in the same sense of movement as the espagnolette mechanism. When the espagnolette slider moves in the direction of arrow 62, the bolt 68 is driven in the direction of arrow 82 to extend out of the bolt unit to a locking condition. When the espagnolette slider moves in the opposition direction, the bolt 68 is retracted relative to the bolt unit 44 to a non-locking position. The bolt 68 engages with a keep unit (not shown here, but of the type shown in Figure 1) to secure the window sash within the frame.

The second bolt unit 46 comprises an L-shaped corner mounting member 84 carrying a counter movement gearbox 86. The gearbox comprises a first rack 88 coupled by bifurcated arms 90 to a serrated socket 92 for engagement with the serrated portion of the espagnolette slider 50, and second rack 92 coupled to a locking bolt 94.

The racks 88 and 92 face each other and are moveably connected by gears 96, to produce the counter-movement. When the espagnolette slider 50 moves in the direction of arrow 62, the first rack moves in the same direction (indicated by arrow 98), and the second rack 92 is driven in a counter direction (indicated by arrow 100) to extend the locking bolt 94 to a locked condition in engagement with a keep unit (not shown). When the espagnolette slider 50 moves in the opposition direction, the second rack is driven in the counter direction to retract the locking bolts 94 from the keep unit.

Figure 5 shows an engagement portion of a shoot bolt mechanism 100 according to an embodiment of the present invention. The shoot bolt mechanism 100 comprises a receiving keep 106 having a keep aperture 112 that receives one end of a shoot bolt 102. The receiving keep 106 comprises screw holes 110 to enable the receiving keep 106 to be connected to a window or door frame (not shown). The shoot bolt 102 comprises a first surface feature 104 consisting of a chamfered face formed

near the one end. The receiving keep 106 comprises a second surface feature 108 also comprising a chamfered face. In normal operation, the shoot bolt 102 freely engages and disengages the keep aperture 112. However, should any attempt be made to force open a window or door to which the shoot bolt mechanism 100 is attached, a lateral force will be generated in the direction of arrow 114. The lateral force pulls the first surface feature 104 and the second surface feature 108 into contact, and this has the effect of preventing the shoot bolt 102 from being withdrawn from the keep aperture 112.

Figure 6 shows an engagement portion of a shoot bolt mechanism 120 according to another embodiment of the present invention. The shoot bolt mechanism 120 comprises shoot bolt 122 housed within an aperture 132 formed within a receiving keep 126. The receiving keep 126 comprises screw holes 130 for mounting the receiving keep 126 within a window or door frame. The shoot bolt 122 comprises a first surface feature 124 consisting of a notch formed proximal the distal end of the shoot bolt 122. The receiving keep 126 comprises a reciprocal second surface feature 128 consisting of a lip formed within the keep aperture 132. In normal operation, the shoot bolt is free to move in and out of the keep aperture 132. However, should any attempt be made to force open a window or door to which the shoot bolt mechanism 120 is attached, a force is generated in the direction of the arrow 134 which pulls the first surface feature 124 into engagement with the second surface feature 128, thereby inhibiting withdrawal of the shoot bolt 122 from the keep aperture 132.

Figure 7 shows an engagement portion of a shoot bolt mechanism 140 according to a further embodiment of the present invention. The shoot bolt mechanism 140 comprises a receiving keep 146 housing an end of a shoot bolt 142 within keep aperture 152. The shoot bolt 142 incorporates circumferential groove 144 proximal to one end. The receiving keep 146 incorporates a circumferential ridge 148 that extends about an inner surface of the keep aperture 152. Additionally, the receiving keep 146 comprises screw holes 150 for attaching the receiving keep 146 to a window or door frame. During normal operation, the end of the shoot bolt 142 is free to move within the keep aperture 152. However, should any attempt be made to force open a window or door to which the shoot bolt mechanism 140 is attached, and thereby generate a lateral component of force in any direction in the plane of arrow

154, the end of shoot bolt 142 will move so that the circumferential groove 144 engages with the circumferential ridge 148, and thereby inhibit retraction of the shoot bolt 142 from the keep aperture 152.

Although the invention has been described in relation to the preceding example embodiments, it will be understood by those skilled in the art that the invention is not limited thereto, and that many variations are possible falling within the scope of the invention. For example, many different arrangements are possible to prevent a shoot bolt from being withdrawn from a receiving keep, and these are intended to fall within the scope of the invention. Additionally, those skilled in the art will be aware that arrangements for latching shoot bolts in receiving keeps should lateral force be applied to the shoot bolts are also possible, and that lateral movement of shoot bolts can be used as a mechanism for triggering intruder alarms, such as, for example, by way forming electrical contacts using a shoot bolt and the receiving keep.

The scope of the present disclosure includes any novel feature or combination of features disclosed therein either explicitly or implicitly or any generalisation thereof irrespective of whether or not it relates to the claimed invention or mitigates any or all of the problems addressed by the present invention. The applicant hereby gives notice that new claims may be formulated to such features during the prosecution of this application or of any such further application derived therefrom. In particular, with reference to the appended claims, features from dependent claims may be combined with those of the independent claims and features from respective independent claims may be combined in any appropriate manner and not merely in the specific combinations enumerated in the claims.

Claims

CLAIMS 1. A window or door system comprising: a frame for mounting in a window or door aperture, the frame incorporating at least one receiving keep; a leaf pivotally coupled to the frame by at least one hinge, wherein the leaf is moveable relative to the frame between closed and open positions ; and a closure mechanism mounted to the leaf for retaining the leaf in the closed position, the closure mechanism comprising: a shoot bolt mechanism further comprising at least one shoot bolt operable to engage a respective receiving keep when the leaf is in the closed position, wherein said at least one shoot bolt has a first surface feature shaped so as to engage a second surface feature formed within the respective receiving keep responsive to an external force being applied to the leaf when in the closed position, wherein any engagement of the first and second surface features is such as to impede withdrawal of the at least one shoot bolt from the respective receiving keep.
2. The window or door system of Claim 1, wherein the closure mechanism further comprises an espagnolette mechanism operatively connected to the shoot bolt mechanism.
3. The window or door system of any preceding claim, wherein at least part of one or more of the frame and the leaf are formed from u-PVC material.
4. The window or door system of any preceding claim, wherein the closure mechanism further comprises a non-latching handle mechanism.
5. The window or door system of any preceding claim, wherein the first and second surface features are mutually co-operating chamfered surfaces.

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6. The window or door system of any preceding claim, wherein the first surface feature comprises a notch and the second surface feature comprises a protrusion, wherein an external force applied to the leaf when in the closed position so as to prise the leaf away from the frame causes the notch to engage with the protrusion.
7. The window or door system of any preceding claim, wherein the first surface feature comprises a groove and the second surface feature comprises a ridge, wherein an external force applied to the leaf when in the closed position so as to prise the leaf away from the frame causes the groove to engage with the ridge.
8. The window or door system of Claim 7, wherein the groove extends about the periphery of the shoot bolt and the ridge extends about the periphery of an aperture formed in the keep.
9. A closure mechanism for mounting to a window or door leaf for retaining the leaf in a closed position, the closure mechanism comprising: a shoot bolt mechanism comprising at least one shoot bolt for engaging at least one receiving keep when the leaf is in the closed position, wherein at least one said shoot bolt has a first surface feature for engaging a second surface feature formed within a respective receiving keep responsive to an external force being applied to the leaf when in the closed position in order to impede withdrawal of the at least one shoot bolt from the respective receiving keep.
10. The closure mechanism of Claim 9, further comprising an espagnolette mechanism operatively connected to the shoot bolt mechanism.
11. The closure mechanism of Claim 9 or Claim 10, further comprising a nonlatching handle mechanism.
12. The closure mechanism of any one of Claims 9 to 11, wherein the first surface feature comprises a chamfered surface.

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13. The closure mechanism of any one of Claims 9 to 12, wherein the first surface feature comprises a notch.
14. The closure mechanism of any one of Claims 9 to 13, wherein the first surface feature comprises a groove.
15. The closure mechanism of Claim 14, wherein the groove extends about the periphery of the shoot bolt.
16. A receiving keep for engaging with the closure mechanism according to any one of Claims 9 to 15.
17. A window or door locking system which comprises an espagnolette locking mechanism, a first locking bolt driven by the espagnolette mechanism and moveable in the same direction as the locking movement of the espagnolette mechanism, and a second locking bolt driven by the espagnolette mechanism and moveable in an opposite direction to the locking movement of the espagnolette mechanism, wherein the first and second locking bolts have respective first surface features for engaging respective second surface features formed within respective receiving keeps responsive to an external force being applied to the window or door when in the closed position in order to impede withdrawal of the locking bolts from the respective receiving keeps.
18. The window or door locking system of Claim 17, wherein the system comprises a first bolt unit carrying the first locking bolt, a second bolt unit carrying the second locking bolt, and a counter movement generator for moving the second locking bolt in an opposite direction to the locking movement of the espagnolette.
19. The window or door locking system of Claim 18, wherein the second bolt unit comprises the counter movement generator.

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20. The window or door locking system of any one of Claims 17 to 19, wherein the system comprises a first rack and a second rack operatively coupled by at least one gear to produce a counter movement.
21. The window or door locking system of any one of Claims 17 to 20, wherein at least one of the locking bolts of the window or door locking system is coupled directly or indirectly to the espagnolette mechanism by way of complementary mating surfaces.
22. A window or door system substantially as hereinbefore described with reference to Figures 5 to 7 of the accompanying drawings.
23. A closure mechanism substantially as hereinbefore described with reference to Figures 5 to 7 of the accompanying drawings.
24. A receiving keep substantially as hereinbefore described with reference to Figures 5 to 7 of the accompanying drawings.