GB2476280A

GB2476280A - Latch assembly having linear actuator and pivoting latch

Info

Publication number: GB2476280A
Application number: GB0922102A
Authority: GB
Inventors: David Thomas Rowe
Original assignee: Securistyle Ltd
Current assignee: Securistyle Ltd
Priority date: 2009-12-17
Filing date: 2009-12-17
Publication date: 2011-06-22
Also published as: GB0922102D0

Abstract

A latch assembly 10 comprises a first member 11, and a second member 12 comprising a latch 13, wherein longitudinal movement of the first member 11 along an axis engages the second member 12 causing the latch 13 to rotate about the axis. Also disclosed are a keep, a cassette, several methods of use and an extruded plastic part for use with the latch assembly.

Description

IMPROVEMENTS IN AND RELATING TO LOCKS

The present invention relates to methods and apparatus for locking windows and doors. In particular, the present invention relates to latch assemblies, keep assemblies, cassettes, methods of night latching, methods of securing premises and methods of adapting the handedness of locks.

Latch assemblies and keep assemblies are often used, in combination, to lock windows and doors for securing premises and for night venting. An example of a known combination is disclosed in GB 2 351 119. Here, the combination consists of a latch mechanism that comprises a first part. The first part has a bolt that is arranged to engage a slot in a second part located on a keep assembly. The second part has a pin arranged to engage the first part. In use, the engagement of the pin with the first part is actuated by longitudinal motion of an espagnolette rod, and engagement of the bolt with the second part is activated by moving a slidably mounted wedge using the pin to cause the bolt to engage the slot.

Another example of a combination is a latch assembly that comprises a rod moveable along a frame between latched and unlatched positions, and a keep assembly comprising a plate having first and second slots for receiving the rod in the latched position. The slots are arranged so that, when the rod is arranged in the second slot, a window on which the latch assembly is mounted provides a night vent so that air may pass through a gap between the window and the frame.

However, a problem can occur when windows or doors are installed in a frame.

Here, the keep assembly has to be located precisely on a frame in order to receive the latch member of a latch assembly. The imprecise location of the keep assembly may lead to the latch member being unable to latch with the keep assembly. Furthermore, the installer has to take account of the required handedness of the window or door, to ensure that the window is able to be opened in the right direction. This leads to it being necessary for an installer to know beforehand the required handedness, or to have several handles having drives of different handedness available for selection during installation.

It is an aim of the present invention to address the problems associated with locking windows and doors whether identified herein or otherwise.

The present invention will be clear from the claims appended hereto and the

description which follows.

According to a first aspect of the present invention, there is provided a latch assembly comprising a first member and a second member comprising a latch. The first member is arranged such that longitudinal movement of the first member along an axis engages the second member to cause the latch to rotate about the axis between active and inactive positions.

The latch assembly may provide an improved means for engaging a latch with a keep. This improvement may be provided by the latch, in use, being arranged to gradually engage a keep during movement from the inactive to the active positions. The keep may be orientated along the axis and may face the same direction in which the latch member rotates so as to receive the latch regardless of the position of the latch in a frame, window or door.

Preferably, the longitudinal movement of the second member along the axis is restricted.

Preferably, the latch is hook shaped. Preferably, the latch extends along an edge of the second member parallel to the axis. This may improve the tolerance with which the latch and keeps may be positioned.

The second member may further comprise an engagement portion. The engagement portion may be arranged to be engaged by the first member to cause the rotation of the latch. Preferably, the engagement portion comprises a plurality of protrusions arranged sequentially along the second member parallel to the axis. Each protrusion may have a leading edge engaged by the first member to cause the rotation of the second member. Preferably, the leading edge defines a sloped region arranged to be engaged by the first member to guide the latch between the active and inactive positions.

The leading edge may terminate at a tip or flat, which may be shaped to resist movement of the second member towards the inactive position.

The second member may be biased towards the inactive position. In one embodiment, the second member is sprung-biased towards the inactive position.

In an alternative embodiment, a mechanical engagement between the first member and the second member controls motion of the latch. More particularly, the mechanical engagement is provided by a pin head moving in a traclc The shape of the trailing edge and leading edge may be chosen so that the handedness of the latch can be easily adapted. The trailing edge may be shaped to be symmetrical to the leading edge. In this way, the handedness of the latch assembly when installed in a frame, window or door may be easy to adapt.

The first member may have at least one guide bay arranged to engage slideably the second member to cause the rotation. Preferably, the guide bay comprises a base region that slopes up to a top region to guide the hooked portion between the active and inactive positions. The top region may be configured to support the hooked portion at the second position and resist unwanted movement of the hooked portion back to the first position.

Preferably, the latch assembly further comprises a chassis incorporating a guide channel in which the first member is slidably movable to cause the rotation of the latch.

The chassis may have a groove arranged along a first axis in which the second member is self-anchored.

The second member may comprise an arm. A first edge of the arm may comprise an anchoring means, which may be arranged at the first axis for pivotally anchoring the second member in the latch assembly, preferably the chassis, suitably the groove of the chassis. An opposed second edge of the arm may comprise the latch and an engagement portion that extend away from each other. The second member may be self-anchored in the chassis with the anchoring means. In the inactive position, the latch may be retracted to a position beneath a surface of the chassis. The latch may be biased towards the inactive position. The latch may be biased towards the inactive position using a spring return mechanism. In the active position, the latch may be extended to a position above the surface of the chassis. The latch may engage a keep in the active position.

Preferably, the latch assembly may further comprise end caps. Each end cap may comprise a shaped portion arranged to conform to the inner profile of the chassis. The ends caps may be friction fitted to the chassis for restricting longitudinal movement of the second member using the shaped portion.

The first member or second member or both may comprise discrete components arranged longitudinally along the axis for varying the lengths of the first and second members. That is, the first or second member may be modular.

According to a second aspect of the present invention, there is provided a keep assembly comprising a base, and first and second keeps. The first and second keeps are arranged to extend substantially perpendicular to the base in a spaced arrangement.

In use, the keep assembly may be arranged on a frame, window or door. The keeps may be orientated for receiving a latch regardless of a desired handedness. The first keep may be used for holding the window or door in a frame with no gap therebetween. The second keep may be used for holding the window or door in a frame with a gap therebetween. The second keep may be used for night venting.

The keeps may be orientated to face in the same direction and extend parallel to each other substantially along the length of the keep assembly. The keeps may be hook shaped. The orientation of the keeps may be determined by the direction in which the latch of a latch assembly rotates.

Preferably, the first keep is movable relative to the second keep for varying the distance between the first and second keeps. Preferably, the first and second keeps lie in a first plane and extend along the keep assembly in a first direction. Preferably, the first keep is movable relative to the second keep in a second direction that is parallel to the first plane and perpendicular to the first direction. The first keep may be arranged to resist movement in a second plane, which is different to the first plane. The position of the second keep in the first plane may be adjusted according to a desired gap between a window or door and a frame for providing a wider gap through which air may flow.

Preferably, the first and second keeps comprise a tongue and groove arrangement configured to fix the first keep to the keep to thereby allow movement parallel to the first plane and resist movement in the second plane.

The keeps may be hook shaped.

The keep assembly may further comprise a camming means. The camming means may comprise an eccentrically extending protrusion. The protrusion may be arranged to pass through base sections of the first and second keeps. Rotation of the camming means about the protrusion may cause the first keep to move relative to the second keep.

In use, a weather seal may be arranged on a window or door frame and/or leaf.

To close the window or door, the leaf is pushed into the frame. In so doing, the weather seal is compressed and forms a seal between the leaf and the frame through which wind, rain and the like are prevented from penetrating.

The camming means may be used to adjust the distance between the first and second keeps to vary a weather seal compression amount. That is, the camming means may be used to adjust the distance that a latch of a latch assembly has to be inserted into the frame before it can be engaged with the first keep to draw the leaf into the frame and form a seal according to an adjusted weather seal compression amount.

Preferably, the second keep comprises a fixing means for securing the keep assembly to a frame, the fixing means may comprise an anchor arranged relative to a first edge of the second keep and an aperture for receiving a screw or bolt, the aperture arranged relative to an opposed second edge of the second keep. Alternatively, the fixing means may comprise an anchor on the first edge and a groove for receiving a tongue, which may, when installed, serve to interference fit the keep to a frame, window or door.

The keep assembly may comprise a latch guide between the first and second keeps. The latch guide may be used for guiding a latch from the first keep to the second keep. The latch guide may be sloped from a tip of the first keep towards a base of the second keep.

According to a third aspect of the present invention, there is provided a cassette comprising a pinion gear for engaging a rack gear. The pinion gear may comprise a toothed quarter wheel.

Preferably, the quarter wheel may have an aperture for receiving a square drive of a handle used to rotate the quarter wheel. Preferably, the aperture may define an axis about which the teeth of the quarter wheel rotate.

Preferably, the pinion gear is located in a housing and is arrangeable according to a desired handedness. The housing may comprise a stop for preventing further rotation of the pinion gear; preferably, an edge of the pinion gear may abut the stop to prevent the rotation. The pinion gear may comprise a first edge and a second edge that extend substantially perpendicularly to each other. The pinion gear may be rotated in the housing according to desired handedness by arranging one of the first or second edges to initially abut the stop.

The latch assembly of the first aspect may comprise a cassette of the third aspect.

The first member of the latch assembly may include a rack gear arranged to be engaged by a pinion gear of the cassette. Rotation of the pinion gear may act upon the rack gear to move the latch between the active and inactive positions.

According to the present invention in a fourth aspect, there is provided a lock assembly that may comprise one or more of the latch assembly of the first aspect, keep assembly of the second aspect and/or cassette of the third aspect. In the lock assembly, 4 I the latch assembly may be arranged to grip one of the first and second keeps of the keep assembly.

According to the present invention in a fifth aspect, there is provided a door or a window or a frame comprising any one of the latch assembly of the first aspect, the keep assembly of the second aspect, and/or the cassette of third aspect. Alternatively, or in addition, the door or window or frame may comprise a lock comprising one or more of the latch assembly of the first aspect, keep assembly of the second aspect and/or cassette of the third aspect. The handedness of the door or window or frame may be adapted according to a desired handedness.

According to the present invention in a sixth aspect, there is provided a method of night latching comprising, firstly, arranging a first member in a frame and a second member in a closing means for closing the frame, the closing means being a window or a door. Then, the closing means is positioned to leave a gap between the frame and the closing means. Finally, the first member is arranged to grip the second member to maintain the gap and resist movement to widen the gap. The first and/or the second member may be hook shaped.

The method of night latching may provide an improved way of securing a closing means to a frame to allow air to pass from one side of the frame to the other through the gap. This improvement in security may be provided by the ability of the first hooked member to be engaged with the second hooked member, preferably along the length of the latch assembly.

The method may comprise arranging the first member on a sloped region arranged to guide the first member to a position in which the first member grips the second member. The method may then comprise moving the first member along the sloped region to engage the second member.

According to the present invention in a seventh aspect, there is provided a method of restricting access to a premises. The method may comprise arranging a first member in a frame and a second member in a closing means for closing the frame, such as a window or door. The first and second members may be hook shaped. Then, preferably, the closing nieans is positioned to close the frame. The first member may then be arranged to grip the second member. Using the grip between the first and second members, unexpected movement of the closing means relative to the frame may be resisted.

The method may involve increasingly engaging the first member with the second member to draw the closing means into the frame, which may make it more difficult for unwanted opening to occur by some attempting to pry the window open.

According to the present invention in an eighth aspect, there is provided a method of adapting the handedness of a window or door. The method comprises locating a toothed quarter wheel for opening and closing a lock for the window or door in a housing, and orientating the teeth of the wheel in the housing according to a desired handedness.

The method may also comprise disengaging the teeth of the wheel from a rack gear to enable the wheel to be orientated, or rotated, and reengaging the teeth with the rack after the wheel has been orientated according to the handedness of a particular installation.

For a better understanding of the present invention and embodiments which put the invention into effect, reference is now made to the accompanying drawings in which:-Figure 1 shows a sectional view of a lock assembly of an embodiment of the present invention in position on a frame and a window or door; Figure 2 shows a perspective view of a latch assembly of an embodiment of the present invention in an active position; Figure 3 shows an exploded view of the latch assembly shown in Figure 2; Figure 4 shows a perspective view of a second member of a latch assembly shown in Figure 2; Figure 5 shows a perspective view of a keep assembly of an embodiment of the present invention; Figure 6A and 6B show a camming means of an embodiment of the present invention for use in the keep assembly shown in Figure 5; Figure 7 shows an alternative embodiment of a keep assembly of the present invention; Figure 8 shows a perspective view of a cassette of an embodiment of the present invention; Figures 9A to 9C show how the cassette of Figure 8 is installed in the latch assembly of Figure 2; Figures 1OA to 1OC show movement of components of the latch assembly shown in Figure 2; Figures 1 1A to 1 lB show a sectional view of a second embodiment of latch assembly featuring a mechanical return mechanism.

Figure 12 shows a perspective view of a first member of a second embodiment of latch assembly according to the present invention; Figure 13 shows a perspective view of a second member of the second embodiment of latch assembly; and Figure 14 shows a sectional view of a vent profile incorporating the latch assembly of the second embodiment.

Figures 1 to 1OC show a first embodiment of a lock assembly 1 of the present invention. The lock assembly 1 is used to lock a window or door in a frame for securing premises and night venting. For these purposes, the lock assembly 1 uses a latch assembly 10, a keep assembly 40 and a cassette 70, which are located in a frame and a window or door. These components 10, 40 and 70 are moveable between active, or latched, positions and inactive, or unlatched positions, to lock or unlock the window or door to the frame.

The latch assembly 10 has a first member 11, such as a slideable bar, which moves longitudinally along an axis to rotate a latch 13 of a second member 12 about a parallel axis 8 between the inactive and active positions. In the active position, the latch 13 is arranged to engage and grip, selectively, one of a first or a second keep 41, 42 of a keep assembly 40; the first and second keeps being arranged to run parallel to each other and parallel to the first and second member 11, 12. The latch is moved between the inactive and active positions by a toothed quarter wheel 71 of a cassette 70. The toothed quarter wheel is meshed with a rack gear 72 of the first member 11, and is arranged according to a desired handedness with which the first member 11 is to be moved to rotate the latch 13.

Figure 2 shows the latch assembly 10 with the latch 13 arranged in the active position. In the active position, the latch 13 (which extends substantially the whole length of the second member) extends above a surface IS of the latch assembly 10 to engage one of the first and second keeps 41,42, in use. In the inactive position, towards which the second member 12 is spring biased, the latch 13 is arranged so that it is retracted to a position beneath a top surface 15 of the latch assembly 10.

The latch assembly 10 uses a chassis 14 to provide a frame, or housing, into which the first and second members 11,12 are located. To aid movement of the latch 13 between the active and inactive position, ends caps 16,17 are arranged at the ends of the chassis 14. Each end cap 16, 17 is positioned in opposed ends of the chassis 14 to retain the first and second members 11,12 and to restrict longitudinal movement of the second member 12 along the axis to urge the latch 13 to rotate. The end caps 16, 17 have a chassis engaging part, shaped to correspond to the inner dimensions of the chassis 14, and a chassis covering part shaped to cover an end of the chassis 14.

Figure 3 shows the components of the latch assembly 10 in more detail. The first member 11 is made up of discrete components, or modules, 18. Each of the components 18 comprises at least one guide bay 19, and can have one, two, three, four or more guide bays. In use, the guide bays 19 are arranged to abut and engage, increasingly, the second member 12 to rotate the latch 13. Each guide bay 19 comprises a base region that slopes up to a top region for guiding the latch between the active and inactive positions. The top region is shaped, or flattened, so as to support the latch 13 in the active position against the bias of a biasing means (not shown) and resists unwanted movement, i.e. malicious movement caused by, for example, a burglar, of the latch 13 back to the inactive position.

The top region of the guide bay 19 can be configured to be any shape or orientation providing it is capable of supporting the latch 13 in the active position.

The length of the first member 11 is varied according to the size of the latch assembly and the second member 12. To do this, a number of components 18 are selected and connected together according to a desired length of rod or bar to be formed.

To connect the components 18 together, each of the components 18 comprises an extension 20 and a slot 21 into which the extension 20 is slot-fitted. The first member can be any suitable length, which is chosen so that it can move slideably within the chassis 14 between the end caps 16, 17 and rotate the latch 13.

The second member 12 comprises a first curved surface 22 along a first edge of which the latch 1 3, which is hook shaped, extends. Along the opposite edge of the first surface 22 an engagement portion 23 is arranged; the engagement portion 23 is arranged to extend away from the latch 13. The second member 12 also includes a second surface, or arm, substantially perpendicular to the first curved surface 22, which at its free edge carries an anchor 24 having a substantially circular cross-section. The latch 13, the engagement portion 23 and the anchor 24 are arranged so that they each extend substantially along the length of the second member 12. To allow air to pass through the second member 12 for night venting, a plurality of apertures are located along its length.

Figure 4 shows the engagement portion 23 in more detail. The engagement portion 23 is made up of a series of waves 25, which extend sequentially along the opposite edge of the first curved surface 22. The curved surface of each wave 25 terminates at an edge. The edge has a leading edge 26 and a trailing edge 27. The leading and trailing edges 26, 27 define sloped regions that are engaged by the first member 11 to cause the rotation of the second member 12.

Between the leading and trailing edges 26, 27, a tip 28 is located. The tip 28 is part of the edge and is configured to be supported by the top region of a guide bay 19 to resist unwanted movement of the latch 13 from the active position to the inactive position. The tip 28 can be any suitable shape or orientation, and can be flattened, so as to provide a region that is supported by the top region of one of the guide bays 19.

From the tip 28, the leading and trailing edges 26, 27 extend. The trailing edge 27 is shaped to be symmetrical to the leading edge 26 and extends from the tip 28 to a region substantially near to a point from which the next leading edge of the next wave in series begins. In this way, the leading edge 26 and trailing edge 27 are reciprocal and their relationship, in terms of which edge leads or trails, is interchangeable according to the required handedness.

Figure 5 shows the keep assembly 40 on which the keeps 41, 42 are arranged to extend substantially perpendicularly from the base 43. The keeps 41, 42 are arranged in a spaced arrangement, i.e. spaced apart from each other, on the base. This arrangement allows, the keep assembly 40 to be engaged by the latch 13 to lock the window or door to the frame in a closed position or a night venting position. In the closed position, air is restricted from flowing between the window or door and the frame and unwanted movement is restricted. In the night venting position, the latch 13 is arranged to grip the second keep 42 to define a gap between the window or door and the frame, through which air can flow. The grip between the latch 1 3 and the second keep 42 also resists unwanted movement to widen the gap. To assist movement of the latch 13 into the night venting position, the first keep 41 has a sloped region 55.

The keeps 4 I, 42 are hooked shaped, and are orientated to face in the same direction as each other on the base 43. The keeps 41,42 extend parallel to each other substantially along the length of the keep assembly 40, and are moveable relative to each other. In use, when the keep assembly 40 is installed in, for example, a frame, the first keep 41, is moveable relative to the second keep 42 to vary the distance between the first and second keeps. This allows the keeps 41, 42 to be adapted during and post installation to, for example, increase the width of the gap used for night venting or for different widths of frame.

To allow the first keep to move relative to the second keep a tongue and groove arrangement is used. This arrangement means that the first and second keeps lie in a first plane and are moveable in that plane, but are arranged to resist movement in a second plane different to the first plane.

To fix the keep assembly 40 to, for example, a frame, a keep anchoring means 49 and a first groove 50 are provided on the second keep 42. The keep anchoring means 49 uses first and second anchor members 51, 52 located either side of a second groove 53.

In use, the parts 51, 52 and 53 are arranged to pinch a flange on the frame. The first groove 50 is located near an edge of the base of the second keep 42 opposed to the edge on which the anchoring means 49 is located. The first groove 50 is, in use, positioned to interference fit on the frame to resist the unwanted movement in the second plane.

Screw holes are provided in the base 43 to fix the second keep to the frame.

Figures 6A and 6B show an eccentric cam 44 that is used to move the first keep 41 relative to the second keep 42. The eccentric cam 44 is substantially circular in cross section and has tab 45 extending from its periphery. A protruding member 46 extends eccentrically from a cam body 47 to engage the base 43 of the second keep 42.

The protruding member 46 of the eccentric cam 44 is positioned through apertures 47, 48 in the bases of the first and second keeps 41, 42 to attach the cam 44 to the base 43 of the second keep 42 and enable the first keep 41 to be moved relative to the second keep by rotation of the cam 44. The apertures 47, 48 are located in alignment in the base of a straight-walled channel 54 of the first keep 41. The aperture on the first keep 41 is elongate in comparison to the second keep 42 to allow the cam ming action to move the first keep 41 relative to the second keep 42. To move the cam 44 a tool engaging part 56 is provided.

In an exemplary embodiment (such as shown in Figure 1), the keep assembly 40 is installed on a frame 80 and the latch assembly 10 is installed on a leaf 81 of a door or window. Weather seals 82a, 82b are arranged to surround one or both of the frame or leaf and are positioned so that a seal is formed when the leaf is in a closed position on the frame. The seals serve to prevent wind, rain and the like from penetrating the window or door.

The strength of the seal formed between the frame and the leaf is determined by a weather seal compression amount. That is, the strength of the seal is determined by how much the leaf 81 and the frame 80 compress the weather seal when closed. The compression amount is determined by a gap between the first and second keeps 41, 42.

The wider the gap between the keeps 41, 42, the more the leaf has to be inserted into the frame before the latch 13 can be engaged with the first keep 41 to draw the leaf into the frame to close the door or window. The cam 44 is used to vary the gap between the first and second keeps. As a result, the cam 44 allows the weather seal compression amount to be varied by increasing or decreasing the gap between the first and second keeps 41, 42.

Figure 7 shows an alternative embodiment of a keep assembly 60 of the present invention. The features of the alternative embodiment are as described above, with reference to Figures 5 and 6, the exception being the sloped region 61. In the alternative embodiment, the sloped region 61 is provided on the second keep 42 to guide the latch 13 into a hooked shaped portion of the second keep 42 to grip the latch 13.

Figures 8 and 9 show the cassette 70 that is used to move the latch assembly 10 between the active and inactive positions according to a required handedness. The cassette has a pinion gear 71, which features a toothed quarter wheel. In use, a plurality of teeth 73 of the wheel are meshed with a rack gear 72 located on a module 18 of the first member 11. A square walled aperture 74 for receiving a square drive is located near a corner 82 of the quarter wheel from which side walls 75, 76 extend; the side walls 75, 76 extending substantially perpendicularly away from each other from the corner 82, which is rounded. To enable the pinion gear to be moved, a handle with square drive (not shown) is engaged with the aperture 74.

The pinion gear 71 is located in a housing 77, and is arranged in the housing according to a desired handedness. The housing 77 has first and second casings 77a and 77b between which the pinion gear 71 is sandwiched. The housing 77 defines a slot 77c on a first surface 78 through which the teeth 73 extend. The housing 77 is closed on an opposed second surface 79. The closed second surface 79 serves to provide a stop for restricting rotation of the pinion gear 71. The cassette 70 is fixed to the latch assembly by, for example, screws or bolts arranged through apertures 80, 81.

Figures 9A to 9C show how the cassette is used to adapt the handedness of a latch assembly 10. Figure 9A shows the pinion gear 71 meshed with the rack gear 72 in a first initial position. The gears 71, 72 are meshed so that anti-clockwise rotation about the square shaped aperture 74 from the first initial position to a first final position causes the pinion gear 71 to move the rack gear 72, and, as a result, to move the latch assembly 10 to the active position according to a first handedness. In the first initial position, the first sidewall 75 abuts the wall 79 of the housing 77 and, in the first final position, the second sidewall 76 abuts the wall 79.

To adapt the handedness of the cassette 70, and, therefore, the lock assembly 1, the cassette 70 is unfixed and the pinion gear 71 is unmeshed from the rack gear 72 as shown by Figure 9B. The un-meshed pinion gear 71 is rotated through 90 degrees about the aperture 74 to a second initial position in which the second sidewall 76 abuts the wall 79 of the housing 77. The pinion gear 71 is then re-meshed with the rack gear 72 and re-fixed, as shown in Figure 9C, to facilitate clockwise movement of the rack gear 72 about the square shaped aperture 74 according to a second handedness. That is, to move the latch assembly 10 to the active position according to a second handedness, the pinion gear 71 is arranged to be moved clockwise from the second initial position to a second final position, in which the first sidewall 75 abuts the wall 79 of the housing 77, according to a second handedness. In this way, the cassette 70 can be easily adapted so that the teeth 73 are rotatable by a user according to a desired handedness.

Figures 1OA to lOC show the movement of the latch assembly between the active and inactive positions. Figure IOA shows the latch assembly 10 in the inactive position.

Here, the first and second members 11, 12 are arranged in an initial position. In the initial position the tip 28 of the wave 25 is arranged at the nadir, or lowest point, of the guide bay 19. Figure lOB shows the second member 12 moving about the axis 8 as the first member II is moved slideably along its axis. As the latch is rotated from its position in Figure lOB to the active position shown in Figure lOC, the latch will grip increasingly a selected keep 41 or 42, to draw the window or door into the frame, as shown in Figure I. In the active position, the tip 28 of the wave 25 is arranged to abut the apex, or highest point, of the guide bay 19, thereby holding the second member 12 extended in its active position.

In use, in the active position the latch 13 is engaged with the first keep 41 to close the window or door in the frame to, for example, secure a premises, or with the second keep 42 to define a gap between the window or door and the frame for night venting. As will be understood, the latch assembly 10 and keep assembly 40 can be positioned and installed at any point around a frame, window or door. The cassette 70 can then engaged with the latch assembly 10, and arranged so that the lock assembly 1 can be adapted according to a desired handedness. In this way, the lock assembly 1 featuring the latch assembly 10, the keep assembly 40 and the cassette 70 provides an improved lock that can be easily installed in a window, door or frame and is readily adaptable to suit an installer's needs.

In accordance with a second embodiment as shown in Figures 11-14, a mechanical engagement is provided between a series of pin heads 84 on the second member 12 and a guide track 85 in the first member 11. As shown more clearly in the cross-sectional views of Figure 1 1A and 1 1B, as a result of longitudinal motion of the first member 11, the second member 12 is driven in to an active position. However, rather than relying on a spring biasing means, when the second member 12 is to be returned to its inactive position, reverse longitudinal motion of the first member 11 causes the second member 12 to retract due to the pin head 84 being engaged within the guide track 85 in the first member 11. Positive mechanical engagement of this kind results in a good reliable mechanical return mechanism.

Turning now to Figure 14, a cross-sectional view of a vent incorporating the present invention is shown. A frame extrusion 90 carries a parallel opening hinge 91 and has positioned within the extrusion a keep 92. The vent extrusion 93 is also connected to the parallel hinge 91 and carries a latch assembly 94 according to the present invention.

In this case, however, the extrusion 93 is shaped to act as a chassis for the latch assembly, so it is simply necessary to insert a first member 11 and a second member 12 to produce a latch assembly according to the present invention. The simplicity of this arrangement facilitates installation and reduces manufacturing costs.

It will of course be understood that the present invention has been described above purely by way of example, and that modifications of the features can be made within the scope of the amended claims.

Claims

Claims:- 1. A latch assembly comprising: a first member, and a second member comprising a latch; wherein longitudinal movement of the first member along an axis engages the second member causing the latch to rotate about the axis between inactive and active positions.
2. The latch assembly of claim 1, wherein longitudinal movement of the second member along the axis is restricted.
3. The latch assembly of claim 1 or claim 2, wherein the latch is hook shaped.
4. The latch assembly of any one of claims 1 to 3, wherein the latch extends along an edge of the second member parallel to the axis.
5. The latch assembly of any preceding claim, wherein the latch is spring biased towards an inactive position.
6. The latch assembly of any preceding claim, wherein a mechanical return mechanism acts between the first member and the second member.
7. The latch assembly of claim 6, wherein the mechanical return mechanism comprises a pin head travelling in a guide track.
8. The latch assembly of any preceding claim, wherein the second member further comprises an engagement portion, the engagement portion arranged to be engaged by the first member to cause the rotation of the latch.
9. The latch assembly of claim 8, wherein the engagement portion comprises a plurality of protrusions arranged sequentially along the second member parallel to the axis; wherein each protrusion has a leading edge engaged by the first member to cause the rotation of the second member.
10. The latch assembly of claim 9, wherein the leading edge defines a sloped region arranged to be engaged by the first member to guide the latch between the active and inactive positions.
11. The latch assembly of any preceding claim, wherein the first member comprises at least one guide bay arranged to engage slideably the second member to cause the rotation.
12. The latch assembly of claim 11, wherein the guide bay comprises a base region that slopes up to a top region to guide the latch between the inactive and active positions; wherein the top region is configured to support the latch at the active position and resist unwanted movement of the latch back to the inactive position.
13. The latch assembly of any preceding claim, further comprising a chassis incorporating a guide channel in which the first member is slidably movable to cause the rotation of the latch.
14. The latch assembly of claim 13, wherein the chassis comprises a groove arranged along the first axis in which the second member is self-anchored.
15. The latch assembly of claim 14, wherein the second member comprises an arm; wherein a first edge of the arm comprises an anchoring means arranged at the first axis for pivotally anchoring the second member in the latch assembly, and an opposed second edge of the arm comprises the latch and an engagement portion that extend away from each other; and wherein the second member is self-anchored in the chassis with the anchoring means.
16. The latch assembly of any one of claims 13 to 15, wherein, in the inactive position, the latch is retracted to a position beneath a surface of the chassis, and, in the active position, the latch is extended to a position above the surface of the chassis.
17. The latch assembly of any one of claims 13 to 16, further comprising end caps, each end cap comprising a shaped portion arranged to conform to the inner profile of the chassis; wherein the ends caps are friction fitted to the chassis for restricting longitudinal movement of the second member using the shaped portion.
18. The latch assembly of any preceding claim, wherein the first member or second member or both comprise discrete components arranged longitudinally along the axis for varying the size of the first and second members.
19. A keep assembly comprising: a base; and first and second keeps; wherein the first and second keeps extend substantially perpendicular to the base in a spaced arrangement.
20. The keep assembly of claim 19, wherein the keeps are orientated to face in the same direction and extend parallel to each other substantially along the length of the keep assembly.
21. The keep assembly of claim 19 or claim 20, wherein the first keep is movable relative to the second keep for varying the distance between the first and second keeps.
22. The keep assembly of claim 21, wherein the first and second keeps lie in a first plane and extend along the keep assembly in a first direction; wherein the first keep is movable relative to the second keep in a second direction that is parallel to the first plane and perpendicular to the first direction; and wherein the first keep is arranged to resist movement in a second plane, which is different to the first plane.
23. The keep assembly of claim 22, wherein the first and second keeps comprise a tongue and groove arrangement configured to fix the first keep to the second keep to thereby allow movement parallel to the first plane and resist movement in the second plane.
24. The keep assembly of any one of claims 19 to 23, wherein the keeps are hook shaped.
25. The keep assembly of any one of claims 19 to 24, further comprising a camming means, the caniming means comprising an eccentrically extending protrusion; wherein the protrusion is arranged to pass through base sections of the first and second keeps; and wherein rotation of the camming means about the protrusion causes the first keep to move relative to the second keep.
26. The keep assembly of any of claims 19 to 25, wherein the second keep comprises a fixing means for securing the keep assembly to a frame, the fixing means comprising an anchor arranged relative to a first edge of the second keep and an aperture for receiving a screw or bolt, the aperture arranged relative to an opposed second edge of the second keep.
27. A cassette comprising a pinion gear for engaging a rack gear; wherein the pinion gear comprise a toothed quarter wheel.
28. The cassette of claim 27, wherein the quarter wheel comprises an aperture for receiving a square drive of a handle used to rotate the quarter wheel; the aperture defining an axis about which the teeth of the quarter wheel rotate.
29. The cassette of any one of claims 27 to 28, wherein the pinion gear is arrangeable in a housing according to a required handedness.
30. A latch assembly of any one of claims 1 to 18 further comprising a cassette of any one of claims 27 to 29, wherein the first member includes the rack gear arranged to be engaged by the pinion gear; wherein rotation of the pinion gear acts upon the rack gear to move the latch between the active and inactive positions.
31. A lock assembly comprising any one of the latch assembly of claims 1 to 18 and 30, the keep assembly of claims 19 to 26, and the cassette of claims 27 to 29; wherein the latch of the latch assembly is arrangeable to grip one of the first and second keeps of the keep assembly.
32. A door or a window comprising one or more components selected from of the latch assembly of claims 1 to 18 and 30, the keep assembly of claims 19 to 26, the cassette of claims 27 to 29, and the lock of claim 31, wherein the handedness of the selected components is adapted according to a desired opening direction.
33. A frame for receiving a window or a door, the frame comprising one or more of the latch assembly of claims 1 to 18 and 30, the keep assembly of claims 19 to 26, the cassette of claims 27 to 29; and the lock of claim 31, wherein the handedness of the selected components is adapted according to a desired opening direction.
34. A method of night venting comprising: arranging a first protruding member in a frame and a second protruding member in a closing means for closing the frame; positioning the closing means to leave a gap between the frame and the closing means; and arranging the first protruding member to grip the second hooked member to maintain the gap and resist movement to widen the gap.
35. A method of restricting access to a premises comprising: arranging a first protruding member in a frame and a second protruding member in a closing means for closing the frame; positioning the closing means to close the frame; arranging the first protruding member to grip the second protruding member; and using the grip of the first and second members to resist unwanted movement of the closing means relative to the frame.
36. The method of claim 34 or 35, wherein the first and/or second protruding members are hook shaped.
37. A method of adapting the handedness of a window or door comprising: locating a toothed quarter wheel for opening and closing a lock for the window or door in a housing; and orientating the teeth of the wheel in the housing according to a required handedness for the window or door.
38. The method of claim 37 further comprising the steps of: disengaging the teeth of the wheel from a gear member to enable the wheel to be orientated; and reengaging the teeth with the gear member after the wheel has been orientated according to the handedness of a user.
39. The method of claim 37 or claim 38 further comprising the steps of: orientating a window or door according to a desired opening direction; and determining the required handedness.
40. An extrusion for a vent or a frame, wherein the extrusion is shaped to receive a latch assembly according to any one of claims 1-18.
41. An extrusion for a vent or a frame, wherein the extrusion is formed with an integral keep.
42. An extrusion as claimed in both claim 40 and claim 41.
43. A latch assembly, a keep assembly, a cassette, a lock assembly or an extrusion substantially as herein described with reference to the drawings.
44. A method of using a latch assembly, keep assembly, cassette, lock assembly or extrusion substantially as herein described with reference to the drawings.