GB2582888A

GB2582888A - Espagnolette Lock

Info

Publication number: GB2582888A
Application number: GB1819456.3A
Authority: GB
Inventors: Sehdeva Richard
Original assignee: Era Home Security Ltd
Current assignee: Era Home Security Ltd
Priority date: 2018-11-29
Filing date: 2018-11-29
Publication date: 2020-10-14
Anticipated expiration: 2038-11-29
Also published as: GB201819456D0; CN111236772A; GB2582888B; CN111236772B

Abstract

An espagnolette lock 1 for a door or window has first 30 and second drive bars 40, and a drive mechanism for driving the drive bars in opposite directions. The drive mechanism has a main gear (50) driving a first gear (52) moving the second drive bar preferably by rack 54. The main gear (50) drives a second gear (53) (idler gear) driving a third gear (55) to move the first drive bar preferably via rack 56. The drive provides a bi-directional motion of the drive bars to improve security. Second drive bar 40 may overlay the first drive bar 30, each drive bar may include a pair of locking cams which slide toward each other during locking movement providing pinching action during locking. Preferably slots in the second drive bar 40 allow movement of the locking cams on the first drive bar 30.

Description

Espagnolette Lock

Technical Field

The invention relates to locking systems for windows and doors. Specifically, the invention relates to, but need not be limited to, espagnolette-type lock assemblies for windows.

Background

Espagnolette-type locks are well-known for use with window assemblies for both private and commercial buildings. They are commonly fitted to the leading edge of a hinged window leaf. Typically, espagnolette locks are usually characterised by a slidable body for fitting to the window leaf which carries projections for engaging with the window frame. The mechanism is often driven by a handle or knob which can be rotated to selectively lock and unlock the window, although motorised versions are also known.

Modern espagnolette locks often comprise multiple locking cams spread along the length of the lock so as to provide additional locking points and thus greater security.

As such they are also often referred to as multi-point locks or MPLs. In simple configurations, the locking cams travel in the same direction during locking. This arrangement is undesirable, since it is possible for the window leaf to be lifted out of alignment by the force applied through the espagnolette lock. This effect is worsened by the flexibility in modern hinges and friction stays, which could even be damaged or bent by the lifting action.

Prior art document GB2300665 describes a ti-parting' arrangement with two espagnolette drive bars which are driven in opposite directions and each provided with a locking pin. During a locking operation, the pins travel in opposite directions to engage the frame, negating the lifting effect.

Prior art document GB2559782 describes a bi-directional' window espagnolette with locking cams arranged in pairs, wherein the locking cams in each pair travel in opposite directions to each other.

The present invention attempts to address or ameliorate one or more of the problems with espagnolette type locks and locking assemblies, or provide a useful alternative.

Summary of Invention

According to a first aspect of the invention, there is provided an espagnolette lock for a door or window. The espagnolette lock may comprise a first drive bar and a second drive bar. The espagnolette lock may comprise a drive mechanism. The drive mechanism may be for driving the first and second drive bars in opposite directions.

The drive mechanism may comprise a main drive gear. The drive mechanism may comprise a first gear. The first gear may be engaged with the main drive gear. The first gear may be configured to drive one of the drive bars. The drive mechanism may comprise a second gear. The second gear may be engaged with the main drive gear and a third gear. The third gear may be configured to drive the other of the drive bars.

The first gear may comprise a pinion gear. The first pinion gear may be engaged with the main drive gear and with a first rack on one of the drive bars. The first rack may be formed on or in, or connected to, one of the drive bars. The second gear may be an idler gear. The third gear may be a pinion gear. The third pinion gear may be engaged with a second rack on the other of the drive bars.

The invention is particularly advantageous, since it provides a simple and reliable mechanism for a bi-directional espagnolette lock.

The espagnolette lock may further comprise at least a first pair and a second pair of locking cams. Each pair of locking cams may comprise a first locking cam and second locking cam. The first drive bar may be connected to the first locking cams. The second drive bar may be connected to the second locking cams. In such embodiments, the espagnolette lock is able to move locking cams in opposite directions, and particularly, locking cams within each pair in opposite directions.

In some embodiments, the first gear and the second gear lie in the same plane. Optionally, the third gear lies in the same plane as the first and second gears. In some embodiments, the main drive gear and the first to third gears all lie in the same plane.

This drive mechanism can thus be made very thin (i.e. with a small width). In some existing products, the drive mechanism for driving each drive bar lies in a separate parallel plane, which thus increases the overall thickness of the drive mechanism.

In some embodiments, the rotational axis of the first gear and the second and/or third gear are parallel. The rotational axis of the main drive gear may be parallel to the rotational axis of any one or more of the first to third gears. The rotational axis of any one or more of the main drive gear and first to third gears may be parallel to the width of the espagnolette lock and/or drive bars.

The drive mechanism may be housed within a gearbox.

In some embodiments, the gearbox has a width smaller than the width of one or both of the drive bars. The gearbox may comprise a first portion with a first width and a second portion. The second portion may have a second, lesser width (i.e. than the first portion).

Preferably, the first and second width of the gearbox are both lesser than the width of one or both of the drive bars. The second portion may be provided on the rear of the gearbox i.e. the side furthest from the drive bars and/or most deeply recessed within a window in use. The gearbox may have a stepped profile.

The gearbox may comprise a housing body. The housing body may comprise an internal cavity. The drive mechanism may be located within the internal cavity. The gearbox may comprise a drive surface. The drive surface may be parallel to the plane of the drive bars. The drive bars may be configured to move relative to the drive surface.

In some embodiments, the first and second drive bars lie against a drive surface on the gearbox. The gearbox may comprise side walls extending from the drive surface. The side walls may be received within grooves in the sides of the first and second drive bars. The side walls may provide additional strength to the espagnolette lock. For example, the side walls may prevent the drive bars from bending when a driving force is applied thereto.

The gearbox may comprise at least one connector. The at least one connector may extend from the gearbox, for example from the drive surface. The at least one connector may extend through slots in the first and second drive bars. The at least one connector may connect to a cover plate. The connector may comprise a threaded tube for receiving a mechanical fastener. Alternatively, the connector may be configured to be riveted over to retain a cover plate. The cover plate may be provided with cover plate holes for connecting with the at least one connector.

The gearbox may be an offset gearbox. The term "offset gearbox", as understood in the field, refers to a gearbox which is not located in a central longitudinal plane which bisects the espagnolette lock. For example, the espagnolette lock may comprise a central plane which bisects the espagnolette lock along its longitudinal axis and the offset gearbox may lie in a plane parallel to the central plane of the espagnolette lock. The gearbox may be spaced transversely from the central plane of the espagnolette lock. For example, the gearbox may be located to one side of the drive bars. In alternative embodiments, the gearbox may comprise an inline gearbox.

The gearbox may comprise a housing body of unitary construction i.e. the housing body may comprise a single component. The gearbox may be formed from metal, for example by die casting, sintering, milling or other suitable process. Alternatively, the gearbox may be formed from plastic, for example, by moulding or other suitable process.

In alternative embodiments, the gearbox may comprise at least a first shell portion a second shell portion. The shell portions may be connectable to form a gearbox and/or housing body.

In some embodiments, the main drive gear may comprise an annular outer portion and an inner portion received within the outer portion. The outer portion may comprise an aperture the same shape as the external profile and/or surface of the inner portion. The inner portion may comprise one or more teeth or projections in its outer surface. The one or more teeth or projections may be configured to prevent rotation of the inner portion relative to the outer portion. The inner portion of the main drive gear may be retained within the outer portion of the main drive gear by a friction or interference fit.

The inner portion of the main drive gear may have a greater width than the outer portion of the main drive gear (i.e. a greater thickness in the width direction of the espagnolette lock 1). The inner portion of the main drive gear may have a width greater than the width of the internal cavity of the gearbox. When assembled, the inner portion of the main drive gear may extend beyond the outer portion of the main drive gear. For example, the main drive gear may have a stepped profile.

The inner portion of the main drive gear may be partly received within an aperture or recess in a wall or walls of the gearbox. The inner portion of the main drive gear may act as an axle or pivot for the main drive gear.

One or more of the first to third gears may comprise an outer gear portion and an axle pin. The axle pin or pins may be partly received within an aperture or recess in a wall or walls of the gearbox. The axle pin may act as an axle or pivot for the first to third gears.

In some embodiments, the main drive gear and/or the first to third gears may be assembled in situ in the gearbox. The outer portion of the main drive gear may be inserted into the internal cavity of the gearbox via an opening in the drive surface. The inner portion of the main drive gear may be inserted into the internal cavity of the gearbox via an aperture in a wall or walls of the gearbox. One or more of the first to third gears may be inserted into the internal cavity of the gearbox via an opening in the drive surface. The axle pins may be inserted into the internal cavity of the gearbox via an aperture in a wall or walls of the gearbox.

Brief Description of the Drawings

Embodiments of the invention will now be described with reference to the following Figures in which: Figure 1 is a perspective view of an espagnolette lock; Figure 2 is a cross-section through the espagnolette lock of Figure 1 in the plane A-A; Figure 3 is an exploded view of an espagnolette lock; Figure 4 is a zoomed in view of the region X of Figure 3; Figure 5A is a perspective view showing the underside of an espagnolette lock; Figure 5B is an end on view of an espagnolette lock; Figure 6A is a partial cutaway of an espagnolette lock; and Figure 6B is a zoomed in view of region Y of Figure 5A.

Specific Description

Turning now to Figure 1, there is shown an espagnolette lock 1 for a window or door.

The espagnolette lock 1 has a gearbox 20, a first drive bar 30 and a second drive bar 40. The gearbox 20 is located approximately in the middle of the length of the two drive bars 30, 40, although in alternative embodiments of the invention the gearbox may be positioned closer to one end of the drive bars 30, 40.

The drive bars 30, 40 are both elongated metal strips, typically formed from steel, such as stainless steel. The drive bars 30, 40 are approximately the same length, and can be provided in a range of sizes depending on the size of the window or door leaf to which they are to be attached. The length of the drive bars 30, 40, and thus the espagnolette lock 1, is their longest dimension. When installed, the length corresponds to the extension of the espagnolette lock along the edge of a door or window leaf.

The drive bars 30, 40 have a narrow width W1, compared to their length. The width is a dimension perpendicular to the length, and also to the plane A-A. In use, the width corresponds to the thickness direction of the door or window leaf. The width of the drive bars 30, 40 is typically approximately 16mm in order for the operating assembly 1 to fit within a conventional euro-profile recess in a door or window leaf. As described below, the width direction is parallel to the rotational axis of the main drive gear.

The thickness of the drive bars 30, 40 can vary, and is typically approximately 1mm thick. The thickness is the dimension perpendicular to the length and width and is the same direction as the depth of the espagnolette lock. In use, the gearbox 20 is recessed into a door or window leaf, and thus espagnolette locks with larger depths require deeper routing into the door or window leaf. The drive bars 30, 40 are thus long and thin plates.

The first and second drive bars 30, 40 are aligned so that they overlap, in the depth direction of the espagnolette lock 1, along their length i.e. the first and second drive bars are stacked on top of each other in the depth direction of the espgnolette lock 1.

The first and second drive bars 30, 40 each have flat surfaces which are abutted against each other. Preferably, the surfaces are the faces of the drive bars 30, 40 defined by the length and width. Both drive bars 30, 40 extend through a region of the gearbox 20 as described below.

When installed in a window or door leaf, the espagnolette lock 1 is recessed into the edge of the window or door. Thus, the second drive bar 40 forms the front of the espagnolette lock 1. The opposite side of the espagnolette lock 1 in the depth direction i.e. the edge of the gearbox 20, is the rear of the lock.

The first drive bar 30 is positioned to the rear of the second drive bar 40, e.g. closer to the gearbox 20 and the rear of the espagnolette lock 1, away from the outermost face of the espagnolette lock 1. That is, when installed in a door or window leaf the second drive bar 40 is the outermost drive bar and thus extends over the top of the first drive bar 30. The drive bars 30, 40 lie in adjacent parallel planes.

Spaced along the length of the drive bars 30, 40 are a series of locking cams 32, 42. The locking cams 32, 42 project away (e.g. in the depth direction, perpendicular to the plane of the drive bars) from the drive bars 30, 40. When installed, the locking cams 32, 42 will thus project away from the edge of the window or door leaf to which they are installed. The locking cams 32, 42 are provided in pairs, with a pair located toward each end of the drive bars 30, 40. At a first end 2 of the espagnolette lock 1, there is provided a first pair of locking cams, made up of a first locking cam 32 and a second locking cam 42. At a second end 3 of the espagnolette lock 1, there is provided a second pair of locking cams, also made up of a first locking cam 32 and a second locking cam 42.

The first locking cam 32 is connected to the first drive bar 30. The second locking cam 42 is connected to the second drive bar 40. The first and second locking cams 32, 42 have the same structure, and the structure of a first locking cam 32 only is described herein, but is applicable to the remaining locking cams 32, 42. Each locking cam 32, 42 is a 'mushroom cam', which each comprise a stem 32b and a head 32a which is wider than the stem 32b. The base of the stem 32b has a flange 32c with a width greater than the stem 32b which contacts and rides against the outer surface of the second drive bar 40, so as to help guide and position the locking cams 32, 42. Since the second locking cam 42 is connected to the second drive bar 40 and doesn't move relatively thereto, the flange 32c sits in position against the surface of the second drive bar 42. Each of the locking cams 32, 42 also has a short tail (not visible) which extends through the drive bar 30, 40 to which it is connected. The tail is riveted over to fix the locking cam 32, 42 to its respective drive bar 30, 40.

Preferably, the tails are located eccentrically (i.e. off the central axis of the stem) of the locking cams 32, 42. Each locking cam 32, 42 is provided with a drive surface, in this case hexagonal recess for receiving an alien key. A user can thus adjust the lateral position (i.e. in the widthwise axis W) of the locking cams 32, 42 by rotating them around their tails. This allows adjustment of the espagnolette lock relative to a keep (not shown), and when installed in a door or window leaf, means that the compression of any peripheral seals can be maintained.

In Figure 1, the second drive bar 40 forms the outermost surface of the operating assembly. The second locking cams 42 are fixed directly on and project from the second drive bar 40. The second drive bar 40 is provided with cam slots 43 through which the tails of the first locking cams 32 extend. The cam slots 43 are aligned lengthwise of the second drive bar 40, thus permitting the first locking cams 32 with a degree of relative movement i.e. the first locking cams 32 can move longitudinally/lengthwise relative to the second drive bar 40.

In alternative embodiments (not shown) the espagnolette lock 1 may be provided with a faceplate which may extend the majority of the length of the espagnolette lock 1. In such embodiments, all of the locking cams 32, 42 will move relative to the fixed faceplate, and thus a slot or slots will be provided for each pair of cams.

With additional reference to Figure 3, toward each of the ends 2, 3 of the espagnolette lock 1, the drive bars 30, 40 are provided with fixing slots 31, 41 in the first and second drive bars 30, 40 respectively. At end 3 the cam slot 43 and the fixing slot 41 comprise regions of a single slot within the second drive bar 40. The fixing slots 31, 41 are aligned so that they overlap, and a mechanical fastener (not shown) can be inserted through the slots 31, 41 in order to attach the end of the drive bars 30. 40 to a door or window leaf. The slots 31, 41 are provided with a fixing plate 10. The fixing plate 10 is formed of a first surface 11, in this case a square plate, and a second surface 12, also a square plate. The first and second surfaces are connected by a spacer (not shown), which extends through the fixing slots 31, 41. The spacer is a rigid tube, and maintains the first and second surfaces 11, 12 a fixed distance apart. The first and second surfaces 11, 12 are wider than the fixing slots 31, 41, thereby preventing the removal of the fixing plate 10 from the operating assembly 1. The fixing plate 10 is configured so that a mechanical fastener (not shown), for example a screw, can be inserted through the spacer and into a door or window leaf in order to fix the espagnolette lock 1 to the leaf. The head of the mechanical fastener would thus engage the first surface 11 of the fixing plate 10. The fixing plate 10 thus provides a method of fitting the operating assembly 1 without restricting the movement of the drive bars 30, 40, since the spacer extends through the fixing slots 31, 41. The rigid spacer and second surface 12 is used to prevent the tightening of the fastener from clamping the drive bars 30, 40 against the door or window leaf, which would impede the movement of the drive bars 30, 40.

Turning now to Figure 2, the configuration and operation of the gearbox 20 will be described.

The gearbox 20 houses a drive mechanism 22. The drive mechanism 22 comprises a set of gears and racks configured to drive the first and second drive bars 30, 40 in different directions.

The drive mechanism 22 comprises a main drive gear 50 engaged with a first gear 52 and a second gear 53. The first gear 52 is in turn engaged with a first rack 54, which is connected to the second drive bar 40. The second gear 53 is in turn connected to a third gear 55, which is engaged with a second rack 56 connected to the first drive bar 30.

The first and second racks 54, 56 are fixed to the drive bars 30, 40 in a similar manner to the locking cams 32, 42 described above. With additional reference to Figure 3, since the first rack 54 is connected to the second drive bar 40, a connector 541 is provided which extends through a slot 33 on the first drive bar 30 to permit relative movement. The connector 541 is fixed to the second drive bar 40 by riveting over the end within the fixing hole 45. Similarly, a connector 561 is provided on the second rack 56 for fixing to fixing hole 35 on the first drive bar 30.

Returning to Figure 2, the main drive gear 50 is provided with teeth 501 around part of its circumference and with a smooth surface 503 on a further, non-toothed part of its circumference. The main drive gear 50 has a central aperture 505 with a square cross-section for receiving a square spindle (not shown) for driving the main drive gear 50.

The square spindle is typically connected to a handle for actuation by a user, or in alternative embodiments (not shown), it may be connected to a mechanical or electronic drive mechanism.

The teeth 501 engage corresponding teeth on the first gear 52, and second gear 53.

Thus, when the main drive gear 50 is rotated (e.g. anti-clockwise as shown by arrow R1), the first and second gears 52, 53 are simultaneously rotated in the opposite direction (clockwise, as shown by arrows R2). Thus, the first gear 52 drives the first rack 54 in the direction D1. On the other hand, the second gear 53 is engaged with the third gear 55, which acts as a reversing gear. When the main drive gear 50 is rotated in the direction R1, the second gear 53 rotates in the direction R2 and drives the third (idler) gear 55 in the direction R1. The third gear 55 thus drives the second rack 56 in the direction D2, opposite to the direction D1. Since the racks 54, 56 are each connected to one of the drive bars 30, 40 the drive bars 30, 40 and subsequently the locking cams 32, 42 are driven in opposite directions simultaneously.

Thus, the mechanism described above can be used to easily and reliably drive multiple locking cams in opposite directions simultaneously. This resolves one of the established problems of the espagnolette lock 'lifting' when all the cams move in a single direction. Additionally, it is desirable to have the locking cams in each pair move towards each other (e.g. a pinching motion) when the espagnolette lock is being locked, and away from each other when being unlocked. This means that the keep on the door or window frame for engaging the locking cams can be kept small, thus reducing cost. A further advantage of this arrangement is that the testing standards for espagnolette locks consider locking cams spaced more than 100mm apart to be separate locking points, and are thus subject to a separate force test. By keeping the locking points 100mm or closer from each other, they can better spread the force from such a test and thus the espagnolette lock is more likely to withstand the force and pass the test.

Turning now to Figures 3 and 4, the construction and assembly of the espagnolette lock will be described.

The gearbox 20 is formed from a housing body 21 in which the drive mechanism 22 is housed. The housing body 21 has a unitary construction and is made from a single component, typically made from metal or a plastics material. The housing body 21 is preferably formed by casting in the case of metals, or moulded for plastics materials, but it could alternatively be milled. The housing body 21 has an internal cavity 29 in which the drive mechanism 22 is located when assembled.

The housing body 21 also has a drive surface 23 which lies flat against the first drive bar 30. The drive surface 23 has a pair of connectors 24 which extend through slots 33, 36, 46 in the first and second drive bars 30, 40 when assembled. The connectors 24 extend to the cover plate 25 where they align with cover plate holes 26, where the connectors 24 are either riveted over or alternatively threaded so as to receive a bolt or screw (not shown). Also extending from the drive surface 23 are a pair of side walls 27. When assembled, the side walls 27 extend past small side grooves in the first and second drive bars 30, 40 and the cover plate 25. The side walls 27 provide additional rigidity and help prevent bending of the first and second drive bars 30, 40 when forces are applied through the drive mechanism 22.

To assemble the espagnolette lock 1, the drive mechanism 22 is first inserted into the internal cavity 29 of the housing body 21. As shown in Figure 4, the main drive gear 50 is formed in two parts: outer main gear portion 50a and inner main gear portion 50b.

The outer portion 50a comprises the gear teeth and is substantially annular, with an internal aperture corresponding to the exterior shape of the inner portion 50b. The inner portion 50b is also generally annular, and comprises an inner aperture 50c with a square cross-section for receiving a spindle from a handle or other drive means such as electrical motor or mechanical assembly. The increased thickness of the inner main gear portion 50b means the inner aperture 50c is deeper than if the main drive gear 50 was a single thickness. This allows for greater positive engagement with a drive spindle for driving the mechanism. The inner portion 50b has a cylindrical outer shape and is provided with a tooth 50d to lock the rotation of the inner and outer portions 50a, 50b together. When assembled (as shown in Figure 4) the inner portion 50b is inserted into the outer portion 50a, wherein it is securely held by a friction or interference fit.

The inner main gear portion 50b has a greater thickness (in the width direction W1) than the outer main gear portion 50a, which forms the stepped shape visible in Figure 4. To position the main gear 50 in the housing body 21, the outer main gear portion 50a is inserted through the opening in the drive surface 23. The inner main gear portion 50b has a thickness greater than the width of the internal cavity 29, and cannot be inserted through the opening in the drive surface 23. The outer main gear portion 50a is thus dropped into position, and the inner main gear portion 50b is inserted through the main gear opening 201 in the housing body 21 into the outer main gear portion 50a to form the assembled main drive gear 50. The inner main gear portion 50b extends through the walls of the housing body 21 and the stepped portion thus bears on the edges of the main gear opening 201 where it acts as an axle around which the main gear 50 rotates. Because the outer main gear portion 50a is larger than the main gear opening 201, and the inner main gear portion 50b is larger than the width of the cavity 29, and thus the assembled main gear 50 is retained securely in position.

Each of the first to third gears 52, 53, 55 is formed in the same manner in two parts. The outer gear portions 52a, 53a, 55a are inserted into the internal cavity and axle pins 52b, 53b, 55b are inserted through apertures 203 in the housing body 21 to secure the assembled gears in position. The ends of the axle pins 52b, 53b, 55b are subsequently riveted over so as to reliably secure the first to third gears 52, 53, 55 in position.

This construction is particularly advantageous, since it keeps the width of the housing body 21 to a minimum. Since the main drive gear 50, and the three gears 52, 53, 55 are all located in a single plane, the internal cavity 29 can be kept very narrow. The width of the internal cavity 29 is equivalent to the thickness of only a single cog -i.e. the outer portions of the main drive gear and first to third gears. In combination with the thickness of the walls of the housing body 21, the overall thickness/width (in direction W1) of the housing body is sufficiently low as to be used within an offset espagnolette gearbox. The second advantage is that each part of the inner and outer portions of the main gear 50 and first to third gears 52, 53, 55 can be extruded (e.g. from brass or other suitable material). Then, the parts can be assembled into the stepped shape of the gears without requiring further expensive machining processes.

The first and second racks 54, 56 are located in the upper edge of the internal cavity in engagement with the first gear 52 and the third gear 55. The first and second drive bars 30, 40 are located against the drive surface 23 and connected to the first and second racks 54, 56 with the connectors 24 extending through the slots 33, 36, 46. The cover plate 25 is positioned over the top of the drive bars 30, 40 and secured by mechanical fasteners through the cover plate holes 26 or by riveting the connectors 24.

With further reference to Figures 5A and 5B, the offset structure of the espagnolette lock 1 is shown. The gearbox 20 has an upper portion 20A and lower portion 20B which both have a width in the direction VV1 smaller than the width of the drive bars 30, 40. The width of the lower portion 20B is less than the width of the upper portion 20A. The gearbox 20 is an offset gearbox i.e. it is positioned off-centre relative to the central plane A-A extending the length of the espagnolette lock 1.

Espagnolette-type locking assemblies are typically provided in either offset or inline varieties. An inline gearbox is one which extends in and is centred on the central plane bisecting the locking assembly (i.e. the plane A-A). In contrast, offset gearboxes are "offset' from this central plane, and are positioned toward the side of the drive bars. Inline gearboxes often extend the full width of the locking assembly, or approximately the full width. Offset gearboxes, however, are much thinner in order to fit within an alternative profile cut or extruded into the window leaf. Typically, an offset gear box has a face which shares an edge with the side or edge of the drive bars. As best shown in Figure 5B, the gearbox 20 is an offset gearbox. The gearbox 20 is located to one side of the assembly, and the lower portion 20B has a width approximately half the width of the drive bars 30, 40. This allows the offset gearbox 20 to fit within the routing provided in, for example, aluminium or wooden window frames which may have a much lower profile than U-PVC frames, and thus less space for receiving the gearbox.

In other embodiments of the invention (not shown), the same gearbox mechanism can be used within an inline gearbox, for example, for use in U-PVC frames.

Turning now to Figures 6A and 6B, there is shown an alternative embodiment 100 of espagnolette lock. The espagnolette lock 100 is substantially the same as the espagnolette lock 1 described previously, and similar features will not be described herein. The drive mechanism 122 within the gearbox 120 is generally the same as described previously. The gearbox 120 differs in that the housing body 121 is formed from two parts. The housing body 121 is formed from a first shell 121A and a second shell (not pictured) which has been removed from the figures. The first shell 121A and second shell can be joined together by any method, preferably by projecting portions which engage with cooperating formations on the other shell portion. The main drive gear and first to third gears can be identical or substantially the same as described previously. Alternatively, it is possible to use single piece gears which are machined, stamped or moulded for example. Shown are single piece gears which comprise axle projections. The axle projections are provided on each side of the first to third gears and engage with apertures or recesses within the first and second shell portions, thereby fixing the gears in position and allowing them to rotate. When closed together, the two shells form a secure gearbox housing body 121. The advantage of this second embodiment is that the assembly of the gearbox is simplified.

In both embodiments of the invention, an advantage of the drive mechanism 22, 122 is that the first and third gears 52, 55 are driven directly by the main drive gear 50. Subsequently, the first and second drive bars are each driven directly by the main drive gear 50. In alternative drive mechanisms (not shown) a main drive gear may be configured to drive only a single drive bar and a reversing mechanism comprising a pair of racks on the drive bars and a pinion gear engaged between the two racks is often used. This is problematic for multiple reasons. Firstly, the gearbox must be enlarged to accommodate the double rack and pinion reversing mechanism. In alternatives, the double rack and pinion reversing mechanism is located outside of the gearbox. In such mechanisms, the drive bars or racks may be very thin and weak, and thus prone to breaking. Other problems include using very small pinion gears to fit within the limited space between the two racks, which are then prone to skipping teeth due to the force applied through the mechanism. In the present invention, the size of the first to third gears is less constrained, and thus greater positive engagement between the gear teeth, both with the other gears and with the first and second racks, can be achieved. The drive mechanism is thus stronger and more reliable, and minimises skipped teeth providing a smooth actuation.

Claims

CLAIMS: 1. An espagnolette lock for a door or window, the espagnolette lock comprising: a first drive bar, a second drive bar, and a drive mechanism for driving the first and second drive bars in opposite directions; wherein the drive mechanism comprises: a main drive gear; a first gear engaged with the main drive gear, the first gear configured to drive one of the drive bars; and a second gear engaged with both the main drive gear and a third gear, wherein the third gear is configured to drive the other of the drive bars.
2. The espagnolette lock according to claim 1, wherein the first gear comprises a pinion gear engaged with the main drive gear and with a first rack on one of the drive bars.
The espagnolette lock according to any one of the preceding claims, wherein the second gear is an idler gear.
4. The espagnolette lock according to any one of the preceding claims, wherein the third gear is a pinion gear engaged with a second rack on the other of the drive bars.
5. The espagnolette lock according to any one of the preceding claims, further comprising: at least a first pair and a second pair of locking cams, each pair comprising a first locking cam and second locking cam; wherein the first drive bar is connected to the first locking cams; and the second drive bar is connected to the second locking cams.
The espagnolette lock according to any one of the preceding claims, wherein the first gear and the second and/or third gear lie in the same plane.
7. The espagnolette lock according to claim 6, wherein the main drive gear and the first, second and third gears all lie in the same plane.
The espagnolette lock according to any one of the preceding claims, wherein the drive mechanism is housed within a gearbox.
9. The espagnolette lock according to any one of the preceding claims, wherein the gearbox has a width smaller than the width of one or both of the drive bars.
10. The espagnolette lock according to claim 9, wherein the gearbox comprises a first portion with a first width and a second portion with a second, lesser width.
11. The espagnolette lock according to any one of claims 8 to 10, wherein the first and second drive bars lie against a drive surface on the gearbox, and wherein the gearbox comprises side walls extending from the drive surface and received within grooves in the sides of the first and second drive bars.
12. The espagnolette lock according to any one of claims 8 to 11, wherein the gearbox comprises at least one connector extending from the gearbox through slots in the first and second drive bars, for connecting to a cover plate.
13. The espagnolette lock according to any one of claims 8 to 12, wherein the gearbox is an offset gearbox.
14. The espagnolette lock according to any one of claims 8 to 13, wherein the gearbox comprises a housing body of unitary construction.
15. The espagnolette lock according to any one of the preceding claims, wherein the main drive gear comprises an annular outer portion and an inner portion received within the outer portion.
16. The espagnolette lock according to claim 15, wherein the inner portion of the main drive gear has a greater width than the outer portion of the main drive gear.
17. The espagnolette lock according to claim 15 or claim 16, wherein the inner portion of the main drive gear is retained within the outer portion of the main drive gear by a friction or interference fit and/or by cooperating formations on the inner portion and/or outer portion.
18. The espagnolette lock according to any one of claims 14 to 17, when dependent upon one of claims 8 to 13, wherein the inner portion of the main drive gear is partly received within an aperture or recess in the walls of the gearbox, and acts as an axle or pivot for the main drive gear.