GB2508940A - Locking unit having a pair of pivotal locking bolts - Google Patents

Abstract

A multipoint locking unit comprising drive means and a pair of pivotal locking bolts/hooks 20a, 20b, which rotate between a retracted position and an extended position. Preferably the locking unit has a primary set of locking bolts and a first and second secondary set of locking bolts (4, 6, 8, fig.2) each consisting of a pair of locking bolts/hooks. The locking unit may be of the espagnolette type having a first and second drive bars driven in opposite. The locking elements may have an engagement portion for cooperating with a keeper and have a toothed body portion driven by drive arms/bar 42, 44 driven in opposite directions via rack and pinions, ultimately driven via toothed cam 36 connected to a handle. The locking bolts in each pair may rotate in opposite directions such that one locking bolt rotates clockwise and the other rotates anti-clockwise. The locking elements may be flush with a surface of a lock casing in the retracted position. Additional locking bolts may be provided as shootbolts (212) and sliding locking pins (208) as corner locking units on a second and third edge of the window (figs. 17-22).

Description

Improvements Relating to Locking Apparatus The present invention relates to locking mechanisms. In particular, the invention relates to locking apparatus for securing and locking a door or a casement window which is disclosed in the specification of the Applicant's UK Patent Application No. 1222751.8 entitled "Improvements Relating to Locking Apparatus", filed 17 December 2012, the subject matter of which is included in the specification of this application and from which this application claims priority. Such locking mechanisms are commonly referred to as "espagnolette" mechanisms. More particularly, this application concerns improvements in, or modifications of, the locking apparatus disclosed in UK Patent Application No. 1222751.8.

Espagnolette-style mechanisms are typically found mounted in PVC, timber and aluminium windows and doors. Such locking mechanisms usually comprise a locking unit which is mounted in the side of the sash of a window or the leaf of a door that is opposed to the hinged side of the window or door. A pair of drive bars typically extend in mutually opposite directions from the locking unit along the side of the window or door adjacent the locking unit. The drive bars tend to be flush with the outer face of the window sash or door leaf adjacent the locking unit.

The locking unit has a drive member, usually connected to a handle. In the prior art each drive bar may have one or more locking elements such as locking studs, which are also known as "mushrooms", arranged thereon. The locking studs are arranged to slide in to and out of engagement with locking keeps located on a surface of a corresponding door jamb or window frame opposite the locking unit and drive bars when the door or window is in a closed configuration.

Operation of the drive member causes longitudinal axial movement of each of the drive bars. Each bar moves in a direction opposite to the other bar to either engage or disengage the locking studs with the keeps. Examples of such locking mechanisms according to the prior art are provided in UK Patent Application Publication Nos. GB 2 264 529 A, GB 2423 792 A and GB 2253241 A. Other locking mechanisms according to the prior art for use with a casement window include further locking elements in addition to the locking studs mentioned above. The further locking elements engage with further locking keeps located in the window frame of the casement window. An example of a locking mechanism having further locking elements is provided in UK Patent Application Publication No. GB 2287 979 A. Rather than having a pair of drive bars, wherein each bar extends from the locking unit in a direction opposite to the other bar, European Patent Application Publication No. EP 1 359 273 Al describes a locking mechanism in which a pair of adjacent drive bars are each engaged with the locking unit at near the middle of each bar. The drive bars are slightly offset from one another. A locking stud is mounted near each end of each bar and the bars may be moved relative to each other to increase or decrease the distance between pairs of adjacent studs mounted on adjacent bars. The studs are brought together by activation of the locking unit to engage with complementary locking keeps.

The locking elements of the prior art extend outwardly from the surface in which they are mounted. Therefore, when designing, manufacturing and installing a door or window according to the prior art, the distance between the door and jambs, or the window and its frame, must fall within a very narrow range to ensure correct engagement between the locking elements and the keeps. The need for such high accuracy increases the cost and time associated with the design, manufacture and installation of doors and windows.

Furthermore, the simple linear movement of the locking elements puts the door or window at risk from burglars. A thief may slide the studs and further locking elements out of engagement by sliding a knife or other thin tool between the door and doorjamb or the window and its frame, engage a stud with the knife and slide the stud out of engagement with its locking keep. Since all the studs and further locking elements are connected, this may result in all the locking elements disengaging with the keeps, thus unlocking the door or window.

Therefore, there is a need for locking apparatus suitable for installation in a door or window that overcomes the limitations of the prior art.

Accordingly, the invention resides in a locking unit suitable for installation in a window sash or door leaf, the locking unit comprising a drive means and a pair of locking elements, wherein activation of the drive means causes rotation of the locking elements between a retracted state and a projecting state.

The invention provides locking elements that rotate from a fully retracted position which may be within a locking unit casing when the locking unit is in the retracted state, to a position where the locking elements may form a pair of projections of the locking unit in the projecting state. According to a preferred embodiment of the invention, in the retracted state the locking elements, and therefore the locking unit, are in an unsecured state, and in the projecting state the locking elements, and therefore the locking unit, are in a secured state suitable for engagement with a securing element which may comprise one or more complementary locking keeps. In the secured state the locking elements may be engaged with the securing element to lock the window or door in the closed position. In the unsecured state the window or door is free to be opened as required.

Advantageously the invention does not require a minimum distance between the window and window frame, or the door and the door jambs, to accommodate the locking elements. Accordingly, the invention simplifies the design, manufacture and installation of doors and windows. This allows for a larger range of variations in the distances between the window and window frame, or the door and the door jambs. A further consequence is that the gap between the window and window frame, or the door and the door jambs, may be reduced.

A result of reducing the gap between the window and window frame, or the door and the door jambs, is that the seals of the door or window may fit more closely around the window frame or door jambs. In addition to the intrinsic difficulty for a thief to gain access to locking elements through the narrower gap provide by the invention, the tight seals also hinder a thief's ability to force open a window or door. Therefore, the invention improves the security of doors and windows.

In a preferred embodiment of the invention the locking elements rotate in mutually opposite directions between the retracted state and the projecting state. Each locking element may comprise a body portion and an engagement portion, and each locking element may be mounted on a pivot pin and may be arranged to rotate about an axis extending through the body portion.

In the retraced state the engagement portions of the pair of locking elements are preferably at their maximum distance from each other. Accordingly, when the locking elements move from the retracted state to the projecting state the distance between the engagement portions may reduce. Consequently, when the locking elements move from the secured state to the unsecured state the distance between the engagement portions may increase.

To protect the locking unit, in particular the drive means and the locking elements, the locking unit may further comprise a casing. In the retracted state the locking elements may be located within the casing. Preferably, in the retracted state, a surface of each of the locking elements may be flush with a surface of the casing to provide a smooth surface to the locking unit.

In contrast, in the projecting state the locking elements may extend from within the casing, so that engagement portions of the locking elements may be exterior to the casing.

Preferably, when the locking elements retract from the projecting state to the retracted state, the locking elements are housed in the casing.

In order to transmit force applied to the drive member to the locking elements the locking unit may further comprise a drive transfer assembly. The drive transfer assembly may be arranged to convert a rotational motion applied to the drive means into a linear motion. In a preferred embodiment, the drive transfer assembly comprises a rack and pinion arrangement to convert between rotational and linear motion. The drive transfer assembly may comprise a first drive arm and a second drive arm which may be linearly moveable. Accordingly, the drive transfer assembly may convert rotational movement of the drive means into linear movement of the drive arms, or may be arranged to transmit linear motion of the drive means into linear movement of the drive bars. The drive transfer assembly may be arranged to move the first drive arm and second drive arm in mutually opposite directions when a force or movement is applied to the drive means.

Advantageously, the drive transfer assembly negates the need for a pair of adjacent,

offset drive bars, as found in the prior art.

To achieve rotation of the locking elements, one of the pair of locking elements may be engaged with the first drive arm and the other of the pair of locking elements may be engaged with the second drive arm. Preferably, the first drive arm and the second drive arm each have a rack portion each engaged with a pinion portion on a respective locking element. Accordingly, linear movement of the drive arms may cause rotational movement of the locking elements.

In a further embodiment of the invention, linear movement first drive arm may cause rotation of one of the pair of locking elements in a first direction, and linear movement of the second diive aim may cause rotation of the othei of the pair of locking elements in the opposite direction.

In a preferred embodiment of the invention, the drive means is in engagement with the first drive arm. In order to transmit force applied to the drive means from the first drive aim to the second dnve aim the drive tiansfei assembly may comprise inteimediate apparatus arranged to transmit the force. Preferably, the intermediate apparatus comprises a pair of pinions.

The drive transfer assembly may compiise at least one iack and at least one pinion. The first drive arm and the second drive arm may each comprise a rack, and the intermediate apparatus may be located between the drive arms. In this configuration, the pair of pinions may be sandwiched between, and engaged with, the iacks of the drive aims.

In a preferred embodiment of the invention the drive means may comprise a drive cam.

The drive cam may have a socket adapted to receive the plug member of a standard window handle. In addition, the drive cam may compnse a pinion portion. A locking unit with a drive means comprising a drive cam may be referred to as a primary locking unit, a the drive means may be activated by a user engaging and turning the handle in the socket of the dnve cam. The rotational motion of the dnve means pieferably results in linear motion of at least one drive bar.

The drive means of a locking unit may comprise a drive bar which may be linked to a primary locking unit. Wheie the diive means of a locking unit compnses a dnve bai linked to a primary locking unit, the locking unit may be referred to as a secondary locking unit. In the configuration of the second locking unit, linear motion of the drive means may result in rotation of the locking elements.

According to another aspect the invention resides in the combination of a locking unit and a securing element, wherein the securing element is arranged to be engageable with the locking unit when it is in the projecting state.

The invention further resides in locking apparatus comprising a first locking unit, a second locking unit and a drive bar, wherein the drive bar is coupled to each of the locking units to transfer a force from the first locking unit to the second locking unit. The first locking unit may comprise a drive cam in the manner of a primary locking unit, mentioned above, and the second locking unit may be a secondary locking unit.

The apparatus may be arranged such that rotational movement of the drive means of the first locking unit results in linear movement of the drive bar. The drive means of the second locking unit may comprise the drive bar. The drive bar may be arranged to move linearly, which may result in rotational movement of the locking elements of at least one locking unit, preferably, the second locking unit.

Preferably, the first and second locking units are mounted on a support bar, and the support bar may be a facia.

In a further embodiment of the invention, the locking apparatus may further comprise a further third locking unit and a further drive bar, wherein the further drive bar is coupled to the first locking unit and the third locking unit to transmit a force from the first locking unit to the third locking unit when a drive member of one of the locking units is activated.

With a view to further enhancing security, particularly of a casement window, advantageously the casement window sash is also locked on the window sash hinge side.

Accordingly, in a preferred embodiment, the locking apparatus for a casement window having window sash locking and window sash hinge sides, the previously mentioned drive means is operable to lock the casement window sash on both the window sash locking and window sash hinge sides.

Advantageously, this is achieved on the window sash locking and hinge sides by providing at least one round corner locking unit and to lock the casement window sash.

By this means the at least one casement window sash locking side and hinge side round corner locking units enable the casement window sash to be locked in a window sash locking side and hinge side corner regions of the casement window sash.

For simplicity of construction and assembly, effectiveness of operation and ease of locking, the at least one casement window sash locking side and hinge side round corner locking units may incorporate a shoot bolt which is operable by the drive means between positions in which it unlocks the casement window sash from, and locks the casement window sash to, the casement window sash frame.

Moreover, locking side and hinge side locking may enhanced still further by including a compression adjustment and locking point in the at least one casement window sash locking and hinge side round coiner units.

Preferably, the compression adjustment and locking point also includes on the locking side a boss membei which extends through a slot in the window sash fascia bai and which is fixed to be moved by the dnve bar between positions in which it unlocks the casement window sash from, and locks the casement window sash to, the casement window sash frame.

Ideally, at least one round corner locking unit is provided to lock the casement window sash on the window sash locking side as well as the window sash hinge side, which preferably also enables the casement window sash to be locked in a window sash locking side and hinge side corner regions of the casement window sash.

The compression adjustment and locking point on the at least one window sash hinge side round corner unit preferably includes a includes a boss member which is fixed to an arm and extends through a slot in an operating bar which the boss member moves between positions in which it unlocks the casement window sash from, and locks the casement window sash to, the casement window sash frame.

By means of the compression locking members, the sash is locked to the frame at two further points on the window sash locking side which further enhances security.

To facilitate translation of the linear movement of the drive bar through 90° around the window sash round corner region on the window sash locking side to the window sash hinge side round corner region, the window sash locking side round corner locking unit preferably includes a flexible strip, for example of spring steel which is fixed to the drive bar, extends around the locking side corner region and is fixed to an operating bar for operating the sash window round corner locking unit on the sash window hinge side.

In a modification of the locking apparatus having first and second locking units as previously mentioned, the second locking unit may be replaced by any of the casement window sash round corner locking units on the casement window sash locking side and sash window hinge side which have been previously referred to.

The invention further resides in a method of operating a locking unit or locking apparatus, the method comprising activating a drive means, wherein movement of the drive means causes iotation of a pail of locking elements between a retiacted state and a projecting state.

The movement of the drive means may be rotational movement and/or linear movement.

Preferably, movement of the drive means results in movement of at least one drive arm.

Movement of the drive means may result in movement of at least one drive bar.

Preferably, the lineal movement of the drive arm or bar in a first direction unlocks, and in an opposite, second direction, locks the casement window sash in the window sash locking side corner region of the casement window sash, and the linear movement of the operating drive arm or bar in a third direction, at right angles to the first direction, unlocks, and in an opposite, fourth direction, locks, the casement window sash in the window sash hinge side corner locking region of the casement window sash.

The lineal movement of the drive arm or bar is conveniently transferred through 900 around a locking side corner region of a casement window sash and though a linearly moveable operating arm or bar to a window sash hinge side locking corner region of the casement window sash.

In order that the present invention may be more readily understood, a preferred embodiment of the present invention will be described, by way example only, with reference to the following drawings, in which:-Figure 1 is a perspective view of locking apparatus according to the present invention; Figure 2 is a side view of the locking apparatus illustrated in Figure 1; Figure 3 is a front view of the locking apparatus illustrated in Figures 1 and 2; Figure 4 is an exploded perspective view of the locking apparatus illustrated in Figures ito 3; Figure 5 is an exploded perspective view of a primary locking unit according to the present invention; Figure 6 is a sectional view of the primary locking unit illustrated in Figure 5 in an unsecured state; Figure 7 is a perspective view of the primary locking unit illustrated in Figures 5 and 6 in the unsecured state; Figure 8 is a sectional view of the primary locking unit illustrated in Figures to 7 in a secured state; Figure 9 is a perspective view of the primary locking unit illustrated in Figures 5 to 8 in the secured state; Figure 10 is a sectional view of the primary locking unit illustrated in Figures 5 to 9 in the secured state and engaged with locking keeps; Figure 11 is a perspective view of the primary locking unit and the locking keeps shown in Figure 10; Figure 12 is an exploded perspective view of a secondary locking unit according to the present invention; Figure 13 is a sectional view of the secondary locking unit illustrated in Figure 12 in an unsecured state; Figure 14 is a perspective view of the secondary locking unit illustrated in Figures 12 and 13 in the unsecured state; Figure 15 is a sectional view of the secondary locking unit illustrated in Figures 12 to 14 in a secure state; Figure 16 is a perspective view of the secondary locking unit illustrated in Figures 12 to 15 in the secure state; Figure 17 is a perspective view of another embodiment specifically for a casement window sash in which the secondary locking units of Figures 1 to 16 are replaced by round corner locking units' which are shown in the unsecured state; Figure 18 is a perspective view of the embodiment of Figure 17, with parts disassembled and broken-away; Figure 19 is a perspective view, to an enlarged scale, of a casement window sash corner region on the window sash locking side of a right-hand round corner locking unit, as illustrated, of Figures 17 and 18, in the secure state; Figure 20 is a side view to a greater enlarged scale of the casement window sash round corner region on the window sash locking side of the right-hand round corner locking unit of Figures 17 and 18; Figure 21 is a perspective view! to an enlarged scale, of casement window sash round corner region on the sash window hinge side of the right-hand round corner locking unit, as illustrated, of Figures 17 and 18 in the secure state; and Figure 22 is a perspective view of the embodiment of Figures 17 to 21 assembled to a casement window sash.

The following specific description describes the invention in use with a casement window. However, the invention described with reference to the embodiments of Figures 1 to 16 is not limited to this use and may alternatively be used with other types of windows or doors, for example.

Figures 1, 2, 3 and 4 show locking apparatus 2 according to the present invention. The locking apparatus 2 comprises a primary locking unit 4, a first secondary locking unit 6 and a second secondary locking unit 8, all according to the present invention. A first drive bar 16 extends between the primary locking unit 4 and the first secondary locking unit 6, and a second drive bar 18 extends between the primary locking unit 4 and the second secondary locking unit 8.

The locking units 4, 6, 8 are mounted on a facia bar 10 by boss members 12 which form a press-fit engagement with complementary facia holes 14 in the facia bar 10. The locking apparatus 2 in use is mounted in a window sash (not shown). When installed in a window sash the locking units 4, 6, 8 may be located within complementary sized mortises, known as a Eurogroove, in the window sash. The surface of the window sash in which the mortises are formed has a recess running between the mortises in which the drive bars 16, 18 are housed, and arranged such that at least part of an outer surface 11 of the facia bar 10 is flush with the surface of the window sash in which the locking apparatus 2 is mounted.

The fascia bar 10 defines open countersunk bores 15 through which respective screws (not shown) may be inserted to secure the locking apparatus 4 to the window sash.

The length of the facia bar 10 is appropriate to the length of the surface of the window in which the locking apparatus 2 is mounted. Typically, the locking apparatus 2 of the invention may be used on windows with sash sizes varying from 200mm up to 1600mm.

However, the invention may be used with larger or smaller windows.

The primary locking unit 4 is in an unsecured state when the locking elements 20a, 2Db, referred to herein as "locking hooks", are in a retracted states whereby the locking hooks 20a, 2Db are retained within the primary locking unit 4, as illustrated in Figures 6 and 7.

When the locking hooks 20a, 2Db project or extend from the primary locking unit 4 in a projecting state, as illustrated in Figures 8 and 9, the locking unit 4 is in a secured state.

In the secured state the locking hooks 20a, 20b are arranged so that each is engageable with a primary locking keep 104a, 104b defined by a securing element 106, as illustrated in Figures 10 and 11. In use, the securing element is mounted in or on the window frame.

In the arrangement illustrated in Figures 10 and 11 the window is locked and secure.

Similarly to the primary locking unit 4, the secondary locking units 6, 8 each have a pair of locking hooks 122a, 122b, 123a, 123b. A secondary locking unit 6, 8 is in an unsecured state when the locking hooks 122a, 122b, 123a, 123b are retained within it, as illustrated in Figures 13 and 14; and is in a secured state when the locking hooks 122a, 122b, 123a, 123b extend from the secondary locking unit 6, 8, as illustrated in Figures 15 and 16.

The facia bar 10 has a pair of primary apertures 22, a pair of first secondary apertures 24 and a pair of second secondary apertures 26. The primary locking unit 4 is mounted on the facia bar 10 such that each locking hook 20a, 20b extends through one of the pair of primary apertures 22 when the primary locking unit 4 is in the secured state. Each of the secondary locking units 6, 8 is similarly mounted on the facia bar 10 such that each locking hook 122a, 122b, 123a, 123b extends through one of the pair of secondary apertures 24, 26 when the secondary locking units 6, 8 are in the secured state.

The components of the primary locking unit 4 are now described with reference to Figures 5 to 9. The primary locking unit 4 comprises a primary casing 28 in which the majority of the components of the primary locking unit 4 are housed. The primary casing 28 has a first primary casing half 28a and a second primary casing half 28b. The first primary casing half 28a has male members 30 which engage with female members 32 on the second primary casing half 28b to form the primary casing 28. The first primary casing half 28a has a first casing aperture 32 and the second primary casing 28b has a second casing aperture 34 aligned in line when the casing halves 28a, 28b are engaged.

A drive means in the form of a primary drive cam 36 is mounted in the casing 28 between the casing halves 28a, 28b. The primary drive cam 36 comprises a pinion portion 38 which extends a quarter of the way around the circumferential surface of the primary drive cam 36. A socket 40 is defined through the centre of the primary drive cam 36 which may be engaged with a complementarily sized drive member (not shown) to rotate the primary drive cam 36 about its rotational axis. The drive member is integral with a handle to enable operation of the primary locking unit by a user. As will be described further below, the user may operate the entire locking apparatus using a handle. The socket is compatible with current common window handle designs.

The primary locking unit 4 further comprises a first locking hook 20a and a second locking hook 20b, which each extend through one of the pair of primary apertures 22 in the facia 10 when the locking unit 4 is in the secure state. A first drive arm 42 extends from the primary locking unit 4 at a first end of the primary locking unit 4, and a second drive arm 44 extends from the primary locking unit at the opposite end of the primary locking unit 4.

The first drive arm 42 has three portions. A first portion 46 at the end of the first drive arm 42 which is located outside of the casing 28 of primary locking unit 4; a central portion 48 which moves to a position external to the casing 28 of primary locking unit 4 in the secured state; and a second portion 50 defined by the innermost end of the first drive arm 42. The portions 46, 48, 50 are arranged in a stepped configuration such that the central portion 48 is generally slightly lower than the first portion 46 and the second portion 50 is generally slightly lower than the central portion 48.

On the upper surface of the first portion 46 of the first drive arm 42 is a female coupling member 52 arranged to receive a push fit complementary male coupling member at a first end of the first drive bar 18 to couple the first drive arm 42 to the first drive bar 18.

The upper surface of the central portion 48 of the first drive arm 42 has a locking hook tray 54 and a locking hook rack portion 56. The upper surface of the second portion 50 has a further rack portion 58. The lower surface of the second portion 50 has a cam drive rack portion 60 engaged with the pinion portion 38 of the primary drive cam 36.

The second drive arm 44 has three portions. A first portion 62 at the end of the second drive arm which is located outside of the casing 28e of the primary locking unit 4; a central portion 64 which moves to a position external to the casing 28 of primary locking unit 4 in the secured state; and a second portion 66 defined by the innermost end of the second drive arm 44. The portions 62, 64, 66 of the second drive arm 44 are arranged in a different configuration than the portions 46, 48 50 of the first drive arm 42. The central portion 64 is generally lower than the first portion 62, but the second portion 66 is higher than the first portion 62.

On the upper surface of the first portion 62 of the second drive arm 44 is a female coupling member 68 arranged to receive a push fit complementary male coupling member at a first end of the second drive bar 16 to couple the second drive arm 44 to the second drive bar 16. The upper surface of the central portion 64 of the second drive arm 44 has a locking hook tray 70 and a locking hook rack portion 72. The lower surface of the second portion 66 has a further rack portion 74.

The second portion 66 of the second drive arm 44 overlies the second poilion 50 of the first drive arm 42. A first pinion 76a and a second pinion 76b are sandwiched between the second portions 50, 66 of the first and second drive bars 42, 44 such that the pinions 76a, 76b are engaged with the further rack portions 58, 74 of the first and second drive arms 42, 44. The pinions 76a, 76b and drive arms 42, 44 are suitably sized so that the upper surfaces of locking hook rack portions 54, 70 of the first and second drive arms 42, 44 are coplanar.

The first and second locking hooks 20a, 2Db are identical and mounted in the primary locking unit 4 in mutually opposite directions. Each locking hook 20a, 2Db has a body portion ha, 77b and an engagement portion 78a, 78b. Each body portion 77a, 77b has a generally flat oblong shape with first flat main surface 80a, 8Db and second flat main surface 82a, 82b. Each first flat main surface 80a, 8Db of a locking hook 20a, 2Db is parallel with the second flat main surface 82a, 82b of that locking hook 20a, 20b. Each engagement portion 78a, 78b is attached to one end of each body portion 77a, 77b.

The main surfaces BOa, 8Db of the first locking hook 20a are linked by an inner side surface 84a and an outer side surface 86a. The inner side surface 84a and the outer side surface 86a are parallel and define the width of the body portion 77a. Similarly, the main surfaces 8Db, 82b of the second locking hook 2Db are linked by an inner side surface 84b and an outer side surface 86b. The inner side surface 84b and the outer side surface 86b are parallel and define the width of the body portion 77b.

Each outer side surface 86a, 86b is shorter than each inner side surface 84a, 84b. A curved pinion portion BBa, 88b is located at the other end of each body portion 77a, 77b and links the inner side surface 84a, 84b of each body portion 77a, 77b to the outer side surface 86a, 86b of each body portion 77a, 77b. Each engagement portion 78a, 78b is wider than the width of the respective body portion ha, 77b such that the cross-section of each locking hook 20a, 2Db defines a T-shaped cross-section. 3D

An open bore 9Da, 9Db extends through each body portion 77a, 77b, in a direction perpendicular to the planes of the main surfaces 8Da, 82a, 8Db, 82b. Each bore 90a, 9Db is arranged to accept a pivot pin 92a, 92b on which each locking hook 20a, 2Db is pivotally mounted to allow radial movement of each pinion portion 88a, 88b about each respective bore 9Da, 9Db.

The pinion portion 88a of the first locking hook 20a is in cooperation with the locking hook rack portion 56 of the first drive arm 42, and the pinion portion 88b of the second locking hook 2Db is in cooperation with the locking hook rack portion 72 of the second drive arm 44.

To switch the state of the primary locking unit 4 between the unsecured state and the secured state a rotational force is applied to the primary drive cam 36 so that it is rotated 900 as indicated by arrow 94 in Figure 6. The drive cam 36 is rotated by engaging the drive member of a standard window handle (not shown) with the socket 40 defined by the drive cam 36. To switch from the unsecured state, as illustrated in Figures 6 and 7, to the secured state, as illustrated in Figures 8 and 9, a rotational force is applied to the primary drive cam 36 shown in Figures 6 and 7 so that it is rotated 90° anticlockwise.

Again, the force is applied using a handle engaged in the socket 40 and turning it accordingly. Of course, if the handle is inserted in the socket 40 on the side of the primary locking unit 4 opposite to the side shown facing the view in the figures, the perspective of rotation for the user of the locking unit 4 is opposite those directions described above. However, the description below describes the operation of the invention as viewed in the figures.

Since the pinion portion 38 of the primary drive cam 36 is engaged with the cam drive rack portion 60 of the first drive arm 42, the anticlockwise movement of the primary drive cam 36 moves the first drive arm 42 in a direction outwardly of the primary locking unit 4 a distance corresponding to the circumferential distance of the pinion portion 38 of the primary drive cam 36.

The linear movement of the first drive arm 42 is translated into clockwise rotational movement of the first pinion 76a and the second pinion 76b through the further rack portion 58 of the first drive arm 42. The rotational movement of the first and second pinions 76a, 76b is translated to liner movement of the second drive arm 44 through the further rack portion 74 of the second drive arm 44. The linear movement of the second drive arm 44 is outwardly of the casing 28 of the primary locking unit 4 a distance corresponding to the circumferential distance of the pinion portion 38 of the primary drive cam 36. The first drive arm 42 and the second drive arm 44 each move in mutually opposite directions concurrently when the primary drive cam 36 is rotated.

In the unsecured state illustrated in Figures 6 and 7, each locking hook 20a, 20b rests on its outer side surface 86a, 86b on its respective locking hook tray 54, 70. In this configuration, each locking hook 20a, 2Db is fully retracted within the casing 28 of the primary locking unit 4. In this configuration, the inner side surface 84a, 84b of each locking hook 20a, 20b is flush with the outer surface 11 of the facia 10.

As described above, the first drive arm 42 has a locking hook rack portion 56 engaged with the pinion portion 88a of the first locking hook 20a, and the second drive arm 44 has a locking hook rack portion 56 engaged with the pinion portion 88b of the second locking hook 20b. As the first drive arm 42 initially moves outwardly from the primary locking unit 4, an end tooth 96 of the locking hook rack portion 56 abuts an end tooth 98 of the pinion portion 88a of the first locking hook 20a. As the first drive aim 42 moves further outwardly, the pinion portion 88a of the first locking hook 20a fully engages with the locking hook rack portion 56. The outwardly movement of the first drive arm 42 serves to rotate clockwise the first locking hook 20a about its pivot pin 92a which lifts the first locking hook 20a from its locking hook tray 54 until it reaches its extended configuration in the secured state wherein the first locking hook 20a projects from the casing 28 of the primary locking unit 4.

The interaction of the second locking hook 2Db and the second drive arm 44 is similar to that described above in relation to the first locking hook 20a and the first drive arm 42. As the second drive arm 44 initially moves outwardly from the primary locking unit 4, an end tooth 100 of the locking hook rack portion 72 abuts an end tooth 102 of the pinion portion 88b of the second locking hook 2Db. As the second drive arm 44 moves further outwardly, the pinion portion 88b of the second locking hook 20b fully engages with the locking hook rack portion 72. The outwardly movement of the second drive arm 44 serves to rotate anticlockwise the second locking hook 2Db about its pivot pin 92b until it reaches its extended configuration in the secured state wherein the second locking hook 20a projects from the casing 28 of the primary locking unit 4.

As illustrated in Figures 10 and 11, in the secured state each locking hook 20a, 20b engages with a complementary shaped primary keep 104a, 104b in the securing element 106. In use, the securing element 106 is mounted in the window frame so that it is opposite the primary locking unit 4 when the window is closed.

At one end of the securing element 106 a first locking keep 104a is defined by a first receiving structure that receives the engagement portion 78a of the first locking hook 20a. At the other end of the securing element 106 a second locking keep 1 04b is defined by a second receiving structure that receives the engagement portion 78b of the second locking hook 2Db. Each receiving structure is defined by a pair of parallel side walls 108, the distance between which is slightly wider than the width of the engagement portions 78a, 78b of each locking hook 20a, 2Db. Extending inwardly from the base of each wall 108 is a flange 110. The distance between the edges of opposed flanges 110 is slightly wider than the width of the body portions 77a, 77b of each locking hook 20a, 2Db. Each receiving structure has an open end 112 and a closed end 114. Accordingly, when a locking hook 20a, 20b moves from its retracted state to its projecting state, it moves through the open end 112 of the receiving structure into engagement with the locking keep 104a, 104b.

When the primary locking unit 4 is in the secured state and the first locking hook 20a is engaged with the first locking keep 104a and the second locking hook 2Db is engaged with the second locking keep 104b. Each locking hook 20a, 2Db -locking keep 104a, lD4b combination is the mirror image of the other. As a consequence of this arrangement, the locking hooks 20a, 2Db cannot be lifted out of the securing element 106 without moving the primary locking unit 4 from the secured state to the unsecured state. Thus the primary locking unit 4 is secured to the securing element 106.

Furthermore, if the primary locking unit 4 is installed in a window sash, and that window sash is lifted upwards when the locking unit 4 engaged with the securing element in the secured state, as one locking hook 2Da, 2Db is forced out of its locking keep 104a, 104b, the other locking hook 2Db, 20a is forced further into its keep lD4b, lD4a and against the closed end 114 of the keep 104b, lD4a. The closed end 114 of the keep 104a, 104b prevents the locking hook from 2Da, 20b from being lifted out of its keep 104a, 104b and becoming fully disengaged. Therefore, the security of the window is maintained.

Each locking hook 20a, 2Db rotates about its respective pivot pin 92a, 92b in a mutually opposite directions, thereby decreasing the distance between the engagement portions 78a, 78b of the locking hooks 2Da, 2Db. Since the engagement portions 78a, 78b enter the securing element 106 on opposite sides of the securing element 106, the locking hooks 20a, 2Db effectively grip the securing element 106 to the locking unit 4 when the locking unit 4 is in the secured state.

To switch the primary locking unit 4 from the secured state to the to the unsecured state, the primary drive cam 36 is rotated 900 clockwise from the position shown in in Figures 8 and 9 to the position shown in Figures 6 and 7. Essentially, the method of operation described above is reversed, as described below.

The clockwise movement of the primary drive cam 36 moves the first drive arm 42 inwardly of the primary locking unit 4 a distance corresponding to the circumferential distance of the pinion portion 38 of the plimary diive cam 36. The linear movement of the first drive arm 42 is translated into anticlockwise rotational movement of the first pinion 76a and the second pinion 76b through the further rack portion 58 of the first drive arm 42. The anticlockwise rotational movement of the fiist and second pinions 76a, 76b is translated to inwardly liner movement of the second drive arm 44 though the further rack portion 74 of the second drive arm 44.

As mentioned above, the first diive arm 42 has a locking hook rack portion 56 engaged with the pinion portion 88a of the first locking hook 20a, and the second drive arm 44 has a locking hook rack portion 72 engaged with the pinion portion 88b of the second locking hook 20b. The inward movement of the drive aims 42, 44 iesults in the anticlockwise lotation of the first locking hook 20a and clockwise lotation of the second locking hook 20b, until each locking hook 20a, 20b rests on its respective tray 54, 70 in the unsecured state.

As described above, the first and second drive arms 42. 44 are coupled to respective second and first drive bars 18, 16. Accordingly, outward and inward movement of the drive arms 42, 44 relative to the primary locking unit 4 results in corresponding movement of the fiist and second drive bars 18, 16.

The components of the first secondary locking unit 6 are now described with reference to Figures 12 to 16 which show the first secondary locking unit 6 in detail. The first and second secondary locking units 6, 8 are identical, but mounted on the facia bar 10 in opposite orientations to allow each secondaiy locking unit 6, 8 to be coupled with each respective drive bar 16, 18. Accordingly, the detailed description of the first secondary locking unit 6 below applies equally to the second secondary locking unit 8.

The first secondary locking unit 6 comprises a secondary casing 116 in which the majority of the complements of the secondary locking unit are housed. The secondary casing 116 has a first secondary casing half liSa and a second secondary casing half 116b. The second secondary casing half 116b has male members 118 which engage with female members 120 on the first secondary casing half 11 6a to form the secondary casing 116. The secondary locking unit 6 further comprises a first locking hook 122a and a second locking hook 122b. Each locking hook 122a, 122b extends through one of the first pair of secondary apertures 24 in the facia 10 when the first secondary locking unit 6 is in the secure state.

The first secondary locking unit 6 has a first drive arm 124, a second drive arm 126 and a drive transfer bar 128 which is slidably housed within the casing 116. The tirst drive bar 16 is connected to the drive transfer bar 128 by a connecting rivet 130 near one end of the drive transfer bar 128. The rivet 130 has a first rivet portion 132 rotatably secured in the drive transfer bar 128, and a second rivet portion 134 rotatably secured in the first drive bar 16. The longitudinal axis of the first livet portion 132 is offset from the longitudinal axis of the second rivet portion 134, so that the axes of the rivet 130 have an eccentric configuration. Accordingly, rotation of the rivet 130 enables the distance between the primary locking unit 4 and the secondary locking unit 6 to be easily adjusted to allow for manufacture tolerances in the facia 10 and drive bar 16.

The second drive arm 126 is secured near the other end of the drive transfer bar 128.

The second drive arm 126 has two portions: a first portion 136 and a second portion 138.

The portions 136, 138 are arranged in a stepped configuration such that the second portion 138 is higher than the first portion 136. The lower surface of the first portion 136 is attached to the drive transfer bar 128 and the upper surface of the first portion 136 of the second drive arm 138 has a locking hook rack portion 140 and a hook rest portion 142. The lower surface of the second portion 138 has a further rack portion 144.

The first drive arm 124 has a generally flat structure and comprises two portions: a first portion 146 and a second portion 148. On the upper surface of the first portion 146 of the reciprocating drive arm are a locking hook rack portion 150 and a hook rest portion 152.

On the upper surface of the second portion 148 is a further rack portion 154.

The second portion 138 of the second drive arm 126 overlies the second portion 148 of the first drive arm 124. A first pinion 156a and a second pinion 156b are sandwiched between the second portions 148, 138 of the first and second drive arms 124, 126 such that the pinions 156a, 156b are engaged with the further rack portions 154, 144 of the first and second drive arms 124, 126. The pinions 156a, 156b and drive arms 124, 126 are suitably sized so that the locking hook rack poitions 150, 140 of the first and second drive arms 124, 126 are coplanar.

The first and second locking hooks 122a, 122b of the secondary locking unit 6 are identical to the locking hooks 20a, 2Db of the primary locking unit 6 described above, and operate in substantially the same way. As above, each locking hook 122a, 122b has an open bore 158a, 158b extending through its body portion 160a, 160b, in a direction perpendicular to the planes of the main surfaces 162a, 162b of the body portions 160a, 16Db. Each bore 158a, 158b is arranged to accept a pivot pin 164a, 164b on which each locking hook 122a, 122b is pivotally mounted to allow iadial movement of the respective pinion portions 166a, 166b about each bore 158a, 158b.

The pinion poition 166a of the fiist locking hook 122a is in coopelation with the locking hook rack portion 154 of the first drive arm 124, and the pinion portion 166b of the second locking hook 122b is in cooperation with the locking hook rack portion 140 of the second drive arm 126.

The drive bar 16 acts as a drive means, linear movement of which applies a linear force to the drive transfer bar 128, thereby resulting in movement of the drive transfer bar 128, which switches the state of the secondary locking unit 6 between the unsecured state, illustrated by Figures 13 and 14, and the secured state, illustrated by Figures 15 and 16.

As described above, when the primary locking unit 4 switches from the unsecured state to the secured state each drive bar 16, 18 moves along its longitudinal axis in a direction away fiom the primary locking unit 4. This movement is transmitted from the fiist diive bar 16 to the drive transfer bar 128 via the rivet 130.

In the unsecured state illustrated in Figures 13 and 14, each locking hook 122a, 122b rests on its outer side surface 168a, 168b on the surface of the respective locking hook tray 152, 142. In this configuiation, each locking hook 122a, 122b is fully retracted within the casing 166 of the secondary locking unit 6, wherein the inner side surface llOa, 17Db of each locking hook 122a, 122b is flush with the outer surface 11 of the facia 10.

Consequently, the second drive arm 126 moves in the direction indicated by arrow 172 in Figure 13 to the position shown in Figure 15. The linear movement of the second drive arm 126 is translated into clockwise rotational movement of the first pinion 1 56a and the second pinion 156b through the further rack portion 144 of the second drive arm 126.

The rotational movement of the first and second pinions 156a, 156b is translated into liner movement of the first drive arm 124 through the further rack portion 154 of the first drive arm 124. The linear movement of the first drive arm 124 is indicated by arrow 174, and the first drive arm 124 moves from the position shown in Figure 13 to the position shown in Figure 15.

As the second drive arm 126 initially moves in the direction of arrow 172, an end tooth 176 of the locking hook rack portion 140 abuts an end tooth 178 of the pinion portion 166b of the second locking hook 122b. As the second drive arm 126 moves further in the direction indicated by arrow 172, the pinion portion 166b of the second locking hook 122b engages with the locking hook rack portion 140. The linear movement of the second drive arm 126 serves to rotate anticlockwise the second locking hook 122b about the pinion pin 164b until it reaches its extended configuration in the secured state whereby it projects from the casing 116 of the secondary locking unit 6.

The interaction of the first locking hook 122a and the first drive arm 124 of the secondary locking unit 6 is similar to that described above in relation to the second locking hook 20b and second drive arm 126. As the first drive arm 124 initially moves in the direction indicated by arrow 174, an end tooth 180 of the locking hook rack portion 150 abuts an end tooth 182 of the pinion portion 166a of the first locking hook 122a. As the first drive arm 124 moves further in the direction indicated by arrow 174, the pinion portion 166a of the first locking hook 122a engages with the locking hook rack portion 150. The linear movement of the first drive arm 124 serves to rotate the first locking hook 122a clockwise about its pinion pin 164a until it reaches its extended configuration in the secured state whereby it projects from the casing 116 of the secondary locking unit 6.

Similarly to the primary locking unit 4, in the secured state each locking hook 122a, 122b of the secondary locking unit 6 engages with a complementary shaped secondary locking keep in a further securing element (not shown) which is identical to the securing element 106 described above with reference to the primary locking unit 4.

In use, further securing elements are mounted in the window frame so that each secondary locking keeps are opposite a secondary locking unit 6 when the window is closed so that the locking hooks 122a, 122b are engageable with secondary locking keeps. Similarly to the primary locking unit 4 and securing element 106, the locking hooks 122a, 122b cannot be lifted out of the secondary locking keeps without moving the secondary locking unit 6 from the secured state to the unsecured state. Thus the secondary locking unit 6 is secured to the further securing element.

To switch the secondary locking unit 6 from the secured state to the unsecuied state, the primary drive cam 36 is rotated 900 clockwise from the position shown in in Figures 8 and 9 to the position shown in Figures 6 and 7, which results in the drive bar 16 moving in a direction toward the primary locking unit 4. This movement results in a corresponding movement of the second drive arm 126 in a direction opposed to the direction indicated by arrow 172, and the movement of the first drive arm 124 in a direction opposed to the direction indicated by arrow 174.

The linear movement of the second drive arm 126 serves to rotate clockwise the second locking hook 122b about its pivot pin 164b until it rests on its respective locking hook tray 142. The linear movement of the first drive arm 124 serves to rotate the first locking hook 122b anticlockwise about its pivot pin 164a until it rests on its respective locking hook tray 152.

The second secondary locking unit 8 operates in essentially the same way as described above in respect of the first secondary locking unit 6. The second secondary locking unit 8 is mounted on the facia 10 in an orientation opposite to the first secondary locking unit 6, i.e. with its first locking hook 123a closest to the primary locking unit 4. The second drive bar 18 acts as a drive means, the activation of which causes the rotation of the pair of locking hooks 123a, 123b of the second secondary locking unit 8 between a retracted state and a projecting state.

In a further embodiment of the invention, one or more alternative secondary locking units (not shown) may be included in the locking apparatus described above for use with large windows. In this further embodiment, the alternative secondary locking unit may have a further drive bar coupled to an alternative embodiment of a second drive arm which is coupled to a secondary locking unit as described above.

In the modification shown in Figures 17 to 22, for a casement window sash 201, the second locking units 6 and 8 of the locking apparatus 2 of Figures ito 16 are replaced in a locking apparatus 200 by right-hand and left-hand casement window sash round corner locking units 202 on the casement window sash locking side 203. The right-hand and left-hand round corner locking units 202 enable the casement window sash 201 to be locked in window sash locking side corner regions 204 of the casement window sash 201.

On the casement window sash hinge locking side 205, there are right-hand and left-hand round corner locking units enable the casement window sash 201 to be locked in window sash locking side round corner regions 207 of the casement window sash 201. Only the right-hand locking unit 206 is shown in Figure 22.

For brevity of description, the right-hand round corner locking unit 202 on the window sash locking side 203, shown in Figures 17, 18, 19,20 and 22, and the right-hand round corner locking unit 206 on the window sash hinge side 205, shown in Figures 17, 18, 21 and 22. only will described in detail as the left-hand round corner locking unit 202 corresponds to, and operates in all material respects to, the right-hand round corner unit 202 and the left-hand round corner locking unit 206 corresponds to and operates in all material respects to, the left-hand round corner unit 206.

Referring more specifically to Figures 19 and 20, the round corner locking unit 202 has a compression adjustment and locking point including a boss member 208 which extends through a slot 210 in the window sash fascia bar 10. As can be seen from Figure 20, the boss member 208 is fixed to the drive bar 18 which is linearly movable when the locking unit 4 (Figures 17 and 18) is operated. The round corner locking unit 202 also includes a shoot bolt 212 which is also linearly movable by the linear movement of the drive bar 18.

Linear movement of the boss member 208 in the slot 210 and of the shoot bolt 212 from the unlocked position shown in Figures 1 7and 18 in the direction of the arrow 214 causes the boss member 208 to engage and be compressed in an unshown rest in the window sash frame (not shown) in a locked position of the window sash 20i and the shoot bolt 212 to project outwardly of the round corner region 204, as shown in Figures 19 and 20, to engage in an unshown recess in the window sash frame (not shown) in a locked position of the window sash 201. Linear movement of the boss member 208 and shoot bolt 212 in the opposite direction, as indicated by the arrow 216 in Figure 20 disengages the boss member 208 from the rest and the shoot bolt 212 from the frame recess so that the window sash 201 occupies an unlocked position.

Referring to Figure 20, the round corner locking unit 202 includes a flexible strip 218, for example of spring steel, which is fixed adjacent its inner end region to the drive bar 18 by a fixing element 220. An arcuate channel 222 carries the flexible strip 218 so that it extends around the window sash corner region 204 to be fixed adjacent its outer end region to an operating bar 226 which is overlaid by a window sash hinge side fascia bar 228. In this way, the linear movement of the drive bar 18 is translated through 90° as indicated by the arrow 224, to effect linear movement of the operating bar in the directions indicated by the arrows 230 and 232 into positions in which the window sash 201 is locked and unlocked respectively on the window sash hinge side 205.

The right-hand round corner locking unit 206 on the casement sash window hinge side has a window sash frame fixing foot 207 extending at a right angle to the operating arm 226 along the window sash 201. And the round locking unit 206 incorporates a compression adjustment and locking point including a boss member 234 which is fixed to an arm 236 and extends through a slot 238 in the operating bar 226. Also, the round corner locking unit 206 includes a shoot bolt 240 which is an extension of the arm 226.

Linear movement of the boss member 234 of the shoot bolt 240 from the unlocked position shown in Figures 17 and 18 in the direction of the arrow 230 causes the boss member 234 to engage and be compressed in an unshown rest in the window sash frame (not shown) in a locked position of the window sash 201 and the shoot bolt 240 to project outwardly of the round corner region 206, as shown in Figure 20, to engage in an unshown recess in the window sash frame (not shown) in a locked position of the window sash 201. Linear movement of the boss member 2 and shoot bolt 212 in the opposite direction, as indicated by the arrow 232 in Figure 20 disengages the boss member 234 from the rest and the shoot bolt 240 from the frame recess so that the window sash 201 occupies an unlocked position.

It will be clear to the skilled person that modifications may be made to the above described systems or methods without departing from the scope of the invention as set out in the following claims.

Claims (62)

1. Claims 1. A locking unit suitable for installation in a window sash or door leaf, the locking unit comprising a drive means and a pair of locking elements, wherein activation of the drive means causes rotation of the locking elements between a retracted state and a projecting state.
2. 2. A locking unit according to Claim 1, wherein in the retracted state the locking elements are in an unsecured state, and in the projecting state the locking elements are in a secured state suitable for engagement with a securing element.
3. 3. A locking unit according to Claim 1 or 2, wherein in the projecting state the locking elements define projections of the locking unit.
4. 4. A locking unit according to any preceding claim, wherein the locking elements rotate in mutually opposite directions between the retracted state and the projecting state.
5. 5. A locking unit according to any preceding claim, wherein each locking element comprises a body portion and an engagement portion.
6. 6. A locking unit according to any preceding claim, wherein each locking element rotates about an axis extending through the body portion.
7. 7. A locking unit according to any preceding claim, wherein each locking element is mounted on a pivot pin.
8. 8. A locking unit according to any preceding claim, wherein in the retraced state the engagement portions of the pair of locking elements are at their maximum distance from each other.
9. 9. A locking unit according to any preceding claim, wherein when the locking elements move from the retracted state to the projecting state the distance between the engagement portions is reduced.
10. 10. A locking unit according to any preceding claim! wherein when the locking elements move from the secured state to the unsecured state the distance between the engagement portions is increased.
11. 11. A locking unit according to any preceding claim, wherein the locking unit further comprises a casing.
12. 12. A locking unit according to Claim 11, wherein in the retracted state the locking elements are located within the casing.
13. 13. A locking unit according to Claim 11 or 12, wherein in the retracted state a surface of each of the locking elements is flush with a surface of the casing.
14. 14. A locking unit according to any of Claims 11 to 13, wherein in the projecting state the locking elements extend from within the casing.
15. 15. A locking unit according to any of Claims 11 to 14, wherein in the projecting state engagement portions of the locking elements are exterior to the casing.
16. 16. A locking unit according to any of Claims 11 to 15, wherein the locking elements retract from the projecting state so that they are housed in the casing in the retracted state.
17. 17. A locking unit according to any preceding claim! wherein the locking unit further comprises a drive transfer assembly arranged to transmit force applied to the drive member.
18. 18 A locking unit according to Claim 17, wherein the drive transfer assembly comprises a first drive arm and a second drive arm.
19. 19. A locking unit according to Claim 18, wherein the drive transfer assembly is arianged to move the first diive arm and second drive aim in mutually opposite directions.
20. 20. A locking unit according to Claim 18 or 19, wherein one of the pair of locking elements is engaged with the first drive arm and the other of the pair of locking elements is engaged with the second drive arm.
21. 21. A locking unit according to any of Claims 18 to 20, wherein linear movement of the drive arms causes rotation of the locking elements.
22. 22. A locking unit according to Claim 21, wherein linear movement first drive arm causes rotation of one of the pair of locking elements in a first direction, and linear movement of the second drive arm causes rotation of the other of the pair of locking elements in the opposite direction.
23. 23. A locking unit according to any of Claims 18 to 22, wherein the first drive arm and the second drive arm each have a rack portion each engaged with a pinion portion on a respective locking element.
24. 24 A locking unit according to any of Claims 18 to 23, wherein the drive means is in engagement with the first drive arm.
25. 25. A locking unit according to any of Claims 18 to 24, wherein the drive transfer assembly comprises intermediate apparatus arranged to transmit the force from the first drive arm to the second drive arm.
26. 26. A locking unit according to Claim 23, wherein the intermediate apparatus comprises a pair of pinions.
27. 27. A locking unit according to any of Claims 18 to 26, wherein the drive transfer assembly comprises at least one rack and at least one pinion.
28. 28. A locking unit according to any preceding claim, wherein the drive means comprises a drive cam.
29. 29. A locking unit according to Claim 28, wherein the drive cam comprises a pinion portion.
30. 30. A locking unit according to Claim 28 or 29. wherein rotational motion of the drive means results in linear motion of at least one drive bar.
31. 31. A locking unit according to any of Claims 1 to 27, wherein the drive means comprises a drive bar.
32. 32. A locking unit according to Claim 31, wherein linear motion of the drive means results in rotation of the locking elements.
33. 33. A locking unit according to any preceding claim and a securing element, wherein the securing element is arranged to be engageable with the locking unit when it is in the projecting state.
34. 34. Locking apparatus comprising a first locking unit according to any of Claims 1 to 33. a second locking unit and a drive bar, wherein the drive bar is coupled to each of the locking units to transfer a force from the first locking unit to the second locking unit.
35. 35. Locking apparatus according to Claim 34. wherein linear movement of the drive bar results in rotational movement of the locking elements of at least one locking unit.
36. 36. Locking apparatus according to Claim 34 or 35, wherein the locking units are mounted on a support bar.
37. 37. Locking apparatus according to Claim 36, wherein the support bar is a facia.
38. 38. Locking apparatus according to any of Claims 34 to 37, comprising a third locking unit and a further drive bar, wherein the further drive bar is coupled to the first locking unit and the third locking unit to transmit a force from the first locking unit to the third locking unit when a drive member of one of the locking units is activated.
39. 39. Locking apparatus including a locking unit according to any of Claims 1 to 34, for a casement window having window sash locking and window sash hinge sides, wherein the drive means is operable to lock the casement window sash on both the window sash locking and window sash hinge sides.
40. 40. Locking apparatus according to Claim 39. wherein at least one round corner locking unit is provided to lock the casement window sash on the window sash locking side.
41. 41. Locking apparatus according to Claim 40, wherein the at least one casement window sash locking side round corner locking unit enables the casement window sash to be locked in a window sash locking side corner region of the casement window sash.
42. 42. Locking apparatus according to any of Claims 39 to Claim 41, wherein at least one round corner locking unit is provided to lock the casement window sash on the window sash hinge side.
43. 43. Locking apparatus according to Claim 42, wherein the at least one casement window sash hinge side round corner locking unit enables the casement window sash to be locked in a window sash hinge side corner region of the casement window sash.
44. 44. Locking apparatus according to any of Claims 40 to 43, wherein the at least one window sash locking side round corner unit incorporates a shoot bolt which is operable by the drive means between positions in which it unlocks the casement window sash from, and locks the casement window sash to, the casement sash frame.
45. 45. Locking apparatus according to Claim 44, wherein the at least one window sash locking side round corner unit includes a compression adjustment and locking point.
46. 46. Locking apparatus according to Claim 45, wherein the compression adjustment and locking point of the window sash locking side round corner unit includes a boss member which extends through a slot in the window sash fascia bar and which is fixed to the drive bar for movement between positions in which it unlocks the casement window sash from, and locks the casement window sash to, the casement window sash frame.
47. 47. Locking apparatus according to Claim 41, or any claim dependent thereon, wherein the at least one casement window sash locking side round corner locking unit includes a flexible strip, for example of spring steel, which is fixed to the drive bar and extends around the window sash corner region to translate linear movement of the drive bar through 90° and is fixed to an operating bar for operating the casement sash window round corner locking unit on the casement sash window hinge side.
48. 48. Locking apparatus according to Claim 47, wherein the at least one casement window sash hinge side round corner unit includes a compression adjustment and locking point.
49. 49. Locking apparatus according to Claim 48, wherein the compression adjustment and locking point on the window sash hinge side round corner unit includes a boss member which is fixed to an arm and extends through a slot in an operating bar which the boss member moves between positions in which it unlocks the casement window sash from, and locks the casement window sash to, the casement window sash frame on the window sash hinge side.
50. 50. Locking apparatus according to Claim 49, wherein the round corner locking unit includes a shoot bolt which is an extension of the said arm which moves the shoot bolt between positions in which it unlocks the casement window sash from, and locks the casement window sash to, the casement window sash frame.
51. 51. A modification of the locking apparatus as claimed in any one of Claims 34 to 38.wherein the second locking unit is replaced by a casement window sash round corner locking unit on the casement window sash locking and hinge sides as claimed in any of claims 39 to 50.
52. 52. A method of operating a locking unit or locking apparatus, the method comprising activating a drive means, wherein movement of the drive means causes rotation of a pair of locking elements between a retracted state and a projecting state.
53. 53. A method according to Claim 52, wherein the movement of the drive means is rotational movement.
54. 54. A method according to Claim 52, wherein the movement of the drive means is linear movement.
55. 55. A method according to any of Claims 52 to 54, wherein movement of the drive means results in movement of at least one drive arm.
56. 56. A method according to any of Claims 52 to 55, wherein movement of the drive means results in movement of at least one drive bar.
57. 57. A method according to Claim 55 or Claim 56, wherein linear movement of the drive arm or bar is transferred through 90° around a locking side corner region of a casement window sash and though a linearly moveable operating arm or bar to a window sash hinge side locking corner region of the casement window sash.
58. 58. A method according to Claim 57, wherein the linear movement of the drive arm or bar in a first direction unlocks, and in an opposite, second direction, locks the casement window sash in the window sash locking side corner region of the casement window sash, and wherein the linear movement of the operating drive arm or bar in a third direction, at right angles to the first direction, unlocks, and in an opposite, fourth direction, locks, the casement window sash in the window sash hinge side corner locking region of the casement window sash.
59. 59. A locking unit or locking apparatus substantially as described herein with reference to one or more ot Figures 1 to 16 of the accompanying drawings.
60. 60. A locking unit or locking apparatus substantially as described herein with reference to one or more of Figures 1 to 16 as modified by one or more of Figures 17 to 22 of the accompanying drawings.
61. 61. A method of switching a locking unit or locking apparatus between a retracted state and a projecting state as described herein with reference to one or more of Figures ito 16.
62. 62. A method of switching a locking unit or locking apparatus substantially as described herein with reference to one or more of Figures 1 to 16 as modified by one or more of Figures 17 to 22 of the accompanying drawings.