GB2509633A

GB2509633A - A friction hinge with releasable restricting means

Info

Publication number: GB2509633A
Application number: GB1405667.5A
Authority: GB
Inventors: Giovanni Laporta
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-05-02
Filing date: 2009-05-02
Publication date: 2014-07-09
Anticipated expiration: 2029-05-02
Also published as: GB2509633B; GB0907637D0; GB2509632B; GB201405669D0; GB201405665D0; GB2469879B; GB201405667D0; GB2509632A; GB2469879A; GB2509434A; GB2509434B

Abstract

A friction hinge comprising a channel, a sash arm, first (35 Fig 12) and second sliders 39 slidably mounted in the channel and restricting means 90 for releasably securing the first slider to the channel, the restricting means being movable between an unreleased configuration (Fig 14), which prevents sliding movement of the first slider and a released configuration (Fig 15) in which the first slider can move relative to the channel, wherein the second slider or an extension thereof is contactable with the restricting means to convert the restricting means to the released configuration. Preferably the channel has lips (31 Fig 12) and opposing recesses (91 Fig 18), the restrictor 90 is urged against the channel by a coil spring 92 and when depressed disengages from the recesses allowing the restrictor to slide underneath the lips of the channel. The restrictor preferably has a portion (94 Fig 15) that slopes towards the base of the channel such that a corresponding sloped portion (96 Fig 15) on the second slider 39 engages with it and causes the restrictor to disengage. This allows the first slider to be moved freely along the channel placing the window into a cleaning or escape position.

Description

FRICTION HINGE

Field of the Invention

The present invention relates to friction hinges for windows, and to fittingsfor windows. The invention is not necessarily limited only to the field of windows, and, for example, couldequally well be applied to doors.

In particular the invention relates to egress hinges for supporting a sash between i closed position in which it lies substantially parallel with a fixed frame and an open position in which the sash extends substantially perpendicular to the fixed frame, however the features of the invention may also be used in other forms of hinge, where appropriate.

Background to the Invention

Friction hinges (also known as friction stays) are commonly used in window assemblies. Figure 1 illustrates a conventional friction hinge of the prior art. In figure 1, the friction hinge includes a fixed member 10 and a lightweight pivoting member 12 coupled to the fixed member by an arrangement of lightweight stays 14.

A slider 16 slides in a channel of the fixed member 10. The pivoting member 1201 sash arm is attachable to a sash, and the pivoting member is movable with respect to the fixed member 10, to move the sash between a closed position in which the pivoting member 12 is parallel with the fixed member 10 and an open position in which the pivoting member 12 is at an angle relative to the fixed member io: The friction hinge of figure 1 has a "restrictor' mechanism, which limits opening movement of the hin9e. This is useful in child safety applications, to ensure that the window is not opened so far that a young child may be in danger of falling out of it.

The front lips of the channel are formed with recesses 18 at predetermined positions corresponding to predetermined open positions of the hinge. Attached to the slider* 16 is a spring biased lever 20 with locking ears 22 which lock in the recesses 18. In use, as the hinge is opened progressively, the slider 18 descends from its uppermost position until ears 22 snap into locking engagement with the uppermost recesses 18. In this position, further opening of the hinge is blocked. In order to overcome the restrictor, the person opening the window has to press the lever 20 inwardly (i.e. towards the fixed member), to release the ears 22 from the recesses 18 and to allow further movement of the slider towards the distal end of the fixed member.

There are other types of hinge commonly used in window assemblies. "Easy-clean" hinges differ from the hinge of figure 1 in that they comprise a first slider that is normally secured in the channel towards the proximal end of the fixed member (i.e. at the apex or nose end of the hinge), and a second slider which is normally movably located towards the distal end of the fixed member. In normal use, opening and closing the window causes the second slider to move towards and away from, respectively, the stationary first slider. In addition to this normal operation, the hinge is also operable in a so-called "easy-clean" mode where the normally fixed first slider can be released so that it can be moved along the channel towards the second slider until a point is reached where the first and second sliders abut one another (or are closely located with respect to one another) towards the distal end of the fixed of the fixed member. When the window is in this position, access to the outside surface of the window is greatly improved so that it can be easily cleaned, for example from inside the house.

Another type of hinge commonly used in window assemblies are "egress" hinges.

Egress hinges are those hinges that can be fully opened to a point where the pivoting member is roughly at 900 to the fixed member. These hinges are particularly useful for fire escapes and the like as the hinge, when it is in its fully opened position, reduces the extent to which the sash obscures the window and hence the extent to which an exit from a building, for example, is obscured.

Egress hinges have similar construction to easy-clean hinges in that they comprise a first slider which is stationary and a second slider, normally located towards the distal end of the fixed member, which is movable along the channel back and forth towards and away from the first slider to open and close the window.

For most conventional hinges, when the pivoting member approaches its closed position, an end point of the pivoting member engages an end cap mounted at one end of the fixed member. Referring to figure 1, the proximal end of the pivoting member 12 has an angled end face 24 which engages a corresponding angled face of an end cap 26 on the end of the fixed member 10 when the hinge is in its closed positiort Such angled end faces and end caps are well known in the prior art. The inter-engagement of these two components can help to improve the pull-in of the sash into the sash opening by providing a compressive force along the axis of the fixed hinge in the closed position, thereby improving the seal around the vent.

Typically the end cap 26 of the fixed member 10 and the end point 24 of the pivoting member are provided as resilient end pieces which are mounted on the ends of the fixed member 10 and pivoting member 12 respectively.

A drawback with inter-engaging end pieces of prior art hinges is that these increase the cost of the hinge, as extra parts are required. Furthermore, the inter-engagement of end pieces of prior art hinges is unreliable; often, the end point of the pivoting member does not engage with the end cap of the fixed member when the hinge is in the closed position, therefore no compressive force is provided to help to pull in the sash as it closes. Another problem is that the end point of the pivoting member becomes misaligned relative to the end point of the fixed member and does not engage properly with the end cap of the fixed member when closing, the improper engagement of the end pieces obstructing closing of the sash.

Summary of the Invention

In accordance with a first aspect of the invention which addresses this and other problems, the invention provides a friction hinge for supporting a sash between a closed position and an open position, the hinge comprising a fixed member, a sash arm for supporting a sash, the fixed member and sash arm being linked by a linkage in use, the linkage comprising at least a first link arm pivotally coupled directly or indirectly to the fixed member and the sash arm, a second link arm pivotally coupled directly or indirectly to the fixed member and the sash arm, and a third link arm pivotally coupled directly or indirectly to the fixed member and the second link arm in use, a first end of the first link arm and a first end of the third link arm being shaped such the said first ends of the first and third link arms interlockingly engage with one another when the sash is in the closed position.

An advantage of the present invention is that no additional end pieces are required to be fitted to the ends of the sash arm and fixed member respectively, in order to help pull in the sash as it closes, as this action is provided by the interlocking engagement of the ends of the first and third link arms. This will decrease the overall cost of the hinge as end cap pieces are not required. Furthermore, in the hinge of the present invention, the reliability of sealing is improved, compression being provided in a mid-portion of the hinge as opposed to an end of the hinge.

Preferably, said first end of the first link arm is hook-shaped and said first end of the third link arm is correspondingly hook-shaped, such that the hook-shaped ends of the first and third link arms interlock when the sash is in the closed position. In this case, the first ends of the first and third link arms will interengage only when the hinge is in the closed position, or near to the closed position.

Alternatively1 said first end of the first link arm and said first end of the third link arm comprise complementary gear teeth, the gear teeth of said first ends of the first and third link arms interlocking in the closed position. In this case, the first ends of the first and third link arms may interengage whilst the hinge is in the closed position and whilst it is moving from the open position to the closed position.

Preferably the fixed member comprises a track or channel in which a slider can slide. Preferably the friction hinge further comprises at least one slider slidable in the channel. Preferably the first and third link arms are pivotally coupled to the slider in use. Alternatively, the second link arm is pivotally coupled to the slider in use. Preferably the friction hinge further comprises first and second sliders1 each slider being slidable in the channel, the first and third link arms being pivotally coupled to the first slider and the second link arm being pivotally coupled to the second slider in use.

Preferably the sash arm has a proximal end and.a distal end, the proximal end of the sash arm having a projection and the fixed member having an end portion comprising a first upstanding member, the first upstanding member having an aperture in which the projection of the sash arm is received when the hinge is in the closed position.

An advantage of the present invention is that since no additional end pieces are required to be filled to the ends of the sash arm and fixed member respectively, in order to help pull in the sash as it closes, security features can be included on the ends of the sash arm and fixed member. The security features used on the ends of the sash arm and fixed member do not need to allow for compression of the end of the sash arm against an end cap of the fixed arm, therefore it is not a requirement that an end face of the sash arm pushes up against a face of an end cap on the fixed member. Such security features as described above can be used on friction hinges1 in isolation, without the features of the first aspect of the invention.

Accordingly, in a further aspect of the invention there is provided a friction hinge for supporting a sash between a closed position and an open position, the hinge comprising a fixed member and a sash arm for supporting a sash, the fixed member and sash arm being linked by an arrangement of link arms in use, the sash arm having a proximal end and a distal end, the proximal end of the sash arm having a projection and the fixed member having an end portion comprising a first upstanding member, the first upstanding member having an aperture in which the projection of the sash ami is received when the hinge is in the closed position.

ln5tead of having ends of the fixed member and sash arm which inter-engage in the closed position to provide a compressive force therebetween, as in some prior art hinges, this aspect of the invention provides a security feature wherein a projection an the proximal end of the sash arm is received within an aperture on the fixed member, when the hinge is in the closed position. This improves security by acting to prevent movement of the sash arm when a lateral force is applied to the sash, perpendicular to the longitudinal axis of the fixed member.

Preferably the projection of the sash arm is hook-shaped. Preferabiy the aperture comprises a through-hole in the first upstanding member. Thisprovides improved security by acting to prevent movement of the sash arm when a force is applied to the sash in any direction perpendicular to the axis of the fixed arm. Preferably the aperture is a substantially rectangular shaped hole.

Preferably the upstanding member is removably attachable to the fixed member.

Preferably the upstanding member comprises an upstanding portion in which the aperture is located and a base portion which lies parallel to the fixed member in use, the fixed member comprising a support track having a bottom, two side walls and a pair of inwardly facing flanges, the base portion of the upstanding member being slidably receivable between the side walls of the support track, the hinge further including means for releasably securing the base portion to the support track.

Preferably the hinge further comprises a plate attached to the sash arm in use, the plate having a hook-shaped end corresponding to the hook-shaped end of the sash arm, the hook-shaped ends of the sash arm and plate being received in the aperture when the hinge is in the closed position. This improves strength of the hinge by increasing the thickness of the proximal end of the sash arm.

Preferably the arrangement of link arms comprises at least a first link arm, the fixed member further having a second upstanding member, the second upstanding member having an aperture, the aperture of the second upstanding member facing substantially perpendicularly to the aperture of the first upstanding member in use and being adapted to receive a projection extending from the first link arm or the sash arm when the hinge is in the closed position. The second upstanding niernber provides further security, by acting to prevent movement of the sash arm in a direction parallel to the axis of the fixed member.

Preferably the projection extending from the first link arm or sash arm is book- shaped. Preferably the first link arm has a first hook-shaped portion, said first hook-shaped portion being received within the aperture of the second upstanding member when the hinge is in the closed position. Preferably the first link arm has a second hook-shaped portion adjacent said first hook-shaped portion.

According to a further aspect of the invention there is provided a kit of parts comprising a friction hinge in accordance with the invention described above, the kit further comprising a second end portion for the fixed member, the first and second end portions being removably attachable to the fixed member, each end portion comprising a first upstanding member having an aperture, the aperture of the first end portion being formed in plastic and the aperture of the second end portion member being formed in metal. The first and second end portions are provided as modular parts for the hinge, which are interchangeable with one another.

According to a further aspect of the invention there is provided a blocking device for use with a friction hinge, the blocking device being receivable within a channel of the friction hinge whereby the blocking device can block movement of a moveable part of the hinge, the blocking device comprising a body portion for blocking the channel, the blocking device being releasably locatable in one or more selectable blocking positions and being removable from the channel.

The blocking device provides a simple means for retaining the window in one of a number of discrete open positons and, in use, prevents the sash from moving from a selected open position to the closed position. This is especially useful for top-hung windows, wherein the weight.of the sash will overcoriie friction in the friction slider, causing the window to close.

Preferably the device further comprises a protruding pin which is receivable within one or more holes in the channel. Preferably the blocking device is releasably engageable in the channel by magnetic engagement. Preferably the blocking device further comprises a permanent magnet which is releasably engageable with the channel. Suitably, the channel can be made of a ferromagnetic material, to which the permanent magnet is attracted.

Preferably the device is locatable on a ferromagnetic plate mounted to a sash or sash frame, for storing the blocking device when not in use to block the channel.

Preferably the body of the device is shaped such that it is removably receivable within a storage groove on a sash or sash frame, for storing the blocking device when not in use to block the channel. The blocking device could be sized and shaped for storage in the eurogroove that is provided as tandard in many sashes.

Preferably the device is for use with a friction hinge, the friction hinge having a channel, a sash arm for supporting a sash, the hinge supporting a sash between a closed position in which the sash arm is substantially parallel to the channel and an open position in which the sash arm is angled relative to the channel, the channel and sash arm being linked by one or more link arms in use, the friction hinge further comprising at least a first slider movable in the channel, at least one link arm being pivotally coupled to the first slider, wherein when the blocking device is located in the channel in a blocking position, movement of the first slider is blocked.

Preferably the blocking device is locatable in one or more selectable blocking positions such that when the hinge is in an open position and the blocking device is 8 -located in the channel in a blocking position, movement of the first slider is blocked, preventing the sash arm from moving to the closed position.

By providing a plurality of discrete blocking positions, the user can select the desired opening angle for the sash and use the blocking device to retain the sash in the selected opening position.

In accordance with a further aspect of the invention there is provided a friction hinge including a blocking device in accordance with the above described aspect of the invention.

A drawback with easy-clean hinges (as described above, easy-clean are egress hinges having first and second sliders, wherein a normally fixed first slider can be released so that it can be moved along the channel towards the second slider allowing better access to the front of the sash for cleaning) is that the first slider is difficult to release. Prior art easy-clean hinges are similar to the hinge shown in figure 1 except that as well as the first slider 16, there is a second slider slidably located towards the distal end of the channel 10. The first slider 16 is fixed by a restrictor 20, which has ears 22, which locate in recesses 18 in the front lips of the channel 10. In order to operate the easy-clean feature, the restrictor 20 must be depressed by the user, releasing the ears 22 from the recesses 18, and whilst the restrictor 20 is depressed the user must apply force to the sash to move the first slider to move distally along the channel 10. The easy-clean feature car be difficult to operate, as it is necessary for the user to both depress the restrictor 20 and to move the first slider at the same time, until the restrictor has fully passed the recesses 18. Often, windows will have friction hinges on two opposite sides of a sash, therefore it will be necessary for the user to depress the restrictor whilst pushing the first slider on each of the two hinges at the same time, in order to activate the easy-clean feature.

In accordance with a further aspect of the invention, there is provided a friction hinge for supporting a sash between a closed position and an open position, the hinge comprising a channel, a sash arm for supporting a sash, first and second sliders slidably mounted in the channel, one or more link arms coupled directly or indirectly to the sliders in use to provide a friction hinge movement of the sash arm relative to the channel, and restricting means for releasably securing the first slider to the channel, the restricting means being movable between an unreleased configuration.

in which it prevents sliding movement of the first slider and a released configuration in which the first slider can move relative to the channel, wherein the second slider or an extension thereof is contactable with the restricting means to convert the restricting means to the released configuration.

This overcomes the problems associated with prior art easy-clean hinges as described above. The first slider can automatically be released from its fixed configuration by opening the sash until the second slider or an extension thereof engages with the restricting means, thereby releasing the first slider; advantageously, therefore, the user does not have to depress the restrictor manually in order to release the first slider from its fixed configuration when using the hinge of the invention. When using the hinge of the present invention, once the restrictor has been converted to the released configuration, the user can then slide the first slider to access the outside surface of the sash. The first slider will automatically return to its unreleased configuration on closing of the sash from indoors. On closing the sash, the second slider slides to the distal end of the channel and the first slider slides to the proximal end of the slider, disengaging the restricting means and the second slider or an extension thereof, allowing the restrictor to return to its unreleased configuration once the first slider reaches the proximal end of the channel. No further actions other than closing the sash are required to convert the restricting means back to the unreleased configuration, the restricting means and the second slider or extension thereof disengaging by the action of the first and second sliders moving away from one another, Of course, the restricting means could also be manually moved to the unreleased configuration by the user sliding the first slider towards the proximal end of the hinge, away from the second slider.

Preferably the friction hinge supports a sash between a closed position and a fully open position, the second slider or extension thereof being contactable with the restricting means when the sash is in the fully open position.

Preferably the sash is movable between a closed position in which the sash arm is substantially parallel to the channel and a fully open position in which the sash arm is substantially perpendicular to the channel.

Preferably the restricting means has a sloped surface which slopes towards the second slider, the second slider or extension thereof being contactable with the sloped surface of the restricting means.

Preferably the second slider or an extension thereof has a sloped surface which slopes towards the first slider, the sloped surface of said second slider or extension thereof being contactable with the restricting means.

Preferably the restricting means has a sloped surface which slopes towards the second slider and the base of the channel and the second slider or extension thereof has a sloped surface which slopes towards the first slider and away from the base of the channel, the sloped surface of the first slider being contactable with the sloped surface of the second slider or extension thereof.

Preferably biasing means is provided to bias the restricting means into its unreleased configuration.

Preferably the biasing means comprises a spring, which in use urges the restricting means away from the channel.

Preferably the channel includes a bottom, two side walls and a pair of inwardly facing flanges, the restricting means or portion thereof engaging with at least one cut-out region in the inwardly facing flanges when the restricting means is in the unreleased configuration. Preferably the restricting means and second slider or extension thereof are adapted such that contact of the second slider or extension thereof with the restricting means moves the restricting means towards the bottom of the channel into the released configuration, whereby in the released configuration the restricting means or portion thereof does not engage with the at least one cut-out region of the inwardly facing flanges.

The restricting means may be attached to the first slider and moves along the channel therewith. Alternatively, the restricting means may be formed integrally with the first slider.

Preferably at least one link arm is pivotally coupled to said first slider and at least one link arm and a further at least one link arm is pivotally coupled to said second slider. The restrictor and means for engaging the restrictor to convert it to the released configuration can therefore be comprised as part of the first and second sliders of an egress hinge.

It is desirable for window hinges, especially hinges which open widely, to be able to restrict the opening of the window in normal use, but to allow full opening of the window when desired. As described above, in relation to figure 1, prior art hinges may include opening restrictors which allow the window to be opened up to a fixed angular position, but not to be opened further until the restrictor is released.

Opening restrictors prevent children from opening a window widely, through which they could fall out, A problem with prior art restrictors 20 of the type shown in figure 1 is that in order to release the restrictor, the restrictor 20 must be depressed by the user, releasing the ears 22 from the recesses 18, and whilst the restrictor is depressed, the user must apply force to the sash to move the slider along the channel. The opening restrictor can be difficult to operate as the user must depress the restrictor and move the slider along the channel at the same time, to allow the restrictor to disengage fully from the recesses 18. Often, windows will have friction hinges on two opposing sides of a sash, therefore it will be necessary for the user to release two opening restrictors in order to fully open the window.

In accordance with a further aspect of the invention there is provided a friction hinge for supporting a sash between a closed position and an open position, the hinge comprising a channel, a sash arm for supporting a sash, a first slider slidably mounted in the channel, one or more link arms coupled directly or indirectly to the first slider in use to provide a friction hinge movement of the sash arm relative to the channel, and restricting means for releasably securing the first slider to the channel, the restricting means being movable between an unreleased configuration, in which it prevents sliding movement of the first slider and a released configuration in which the first slider can move relative to the channel, the restricting means engaging magnetically with the channel when the restricting means is in the released configuration.

This overcomes the problems highlighted above, as the user does not need to simultaneously depress the restrictor and move the slider; instead, the user can first depress the restrictor towards the bottom of the channel, until it magnetically engages with the bottom of the channel, and is held in its depressed position. The user can then move the slider by applying force to the slider directly or by applying force to the sash.

Preferably the restricting means includes a permanent magnet and the channel having a bottom, the bottom of the channel or a portion thereof being ferromagnetic, the permanent magnet of the restricting means magnetically engaging with a bottom of the channel, when the restricting means is in the released configuration.

Preferably biasing means is provided to bias the restricting means into its unreleased configuration. Preferably the biasing means comprises a spring. The spring urges the restricting means away from the bottom of the channel.

Preferably the restricting means is engageable with a portion of the channel, preventing movement of the first slider. Once the restricting means has been depressed towards the channel, it is held in this position by magnetic attraction, and no longer engages with said portion of the channel. Preferably the channel includes a bottom, two side walls and a pair of inwardly facing flanges, the restricting means or portion thereof being engageable with at least one cut-out region in the inwardly facing flanges, preventing movement of the first slider. Preferably the restricting means is convertible from the unreleased configuration to the released configuration by movement of the restricting means in a direction towards the bottom of the channel, whereby the restricting means or portion thereof is disengageable from the at least one cut-out region of the inwardly facing flanges.

Preferably the bottom of the channel is ferromagnetic and includes a non-ferromagnetic region, wherein when moving the hinge from the open position to the closed position, the restricting means is moveable over the non-ferromagnetic region, whereby, the restricting means is released from magnetic engagement with the channel.

Preferably the bottom of the channel includes an aperture, wherein when moving the hinge from the open position to the closed position, the restricting means is moveable over the aperture, whereby the restricting means is released from magnetic engagement with the channel. Preferably the aperture is in close proximity to the cut-out region in the inward facing flanges. During movement of the hinge from its un-restricted open position to its closed position, the restrictor passes ovir the aperture; the restrictor disengages from the channel, as there is no longer any magnetic attraction between the magnet and the channel, allowing the restrictor to return to its unreleased configuration.

The restricting means may be attached to the first slider and moves along the channel therewith. Alternatively, the restricting means may be formed integrally with the first slider. The restricting means may be located proximally or distally relative to the slider.

According to a further aspect of the invention, there is provided a friction hinge for supporting a sash between a dosed position and an open position, the hinge comprising a channel, a sash arm for supporting a sash, a first slider slidably mounted in the channel, one or nore link arms coupled directly or indirectly to the first slider in use to provide a friction hinge movement of the sash arm relative to the channel, and blacking means for preventing first slider from moving the sash from the open position to the closed position, the channel having a bottom, two side walls and a pair of inwardly facing flanges and at least one cut-out region in the inwardly facing flanges, the blocking means being attached to or integral with the first slider in use and having at least one chamfered surface, such that the sash is movable from the dosed position to an o$n position but is prevented from moving from the open position to the closed position by engagement of a portion of the blocking means with said at least one cut-out region in the inwardly facing flanges, An advantage of the fifth aspect of the invention is that the sash can be retained in an angular position (such as the fully open position in which the sash arm is angled at around 9Q0 to the channel) automatically, once the sash has been opened to a pre-determined angular position; no further action is required by the user to lock the sash into the pre-determined open position. This is especially useful for egress top-hung windows, wherein in the event of a fire the window can be opened fully until the sash arm is angled 90° relative to the channel wherein the opening is wide enough for a person to escape through the window, and the sash will automatically be retained in the fully open position by action of the blocking means, without closing.

Preferably the blocking means is convertible between an unreleased configuration in which said portion of the blocking means is in engagement with said at least one cut-out region in the inwardly facing flanges and a released configuration in which said portion of the blocking means is disengaged from said at least one cut-out region and the sash is movable from the open position to the closed position.

Preferably biasing means is provided to bias the blocking means into its unreleased configuration. The biasing means can be overcome by the user applying pressure, manually to the blocking means. Preferably the biasing means is a spring.

Preferably the channel has a proximal end and a distal end, the first slider moving from the distal end of the channel towards the proximal end as the sash is moved from the closed position to the open position, said at least one chamfered surface of the blocking means sloping down towards the bottom of the channel in the direction towards the proximal end of the channel.

The blocking means may be releasably attached to the first slider. Alternatively the blocking means is formed integrally with the first slider.

A drawback with the types of hinges previously illustrated is that it can be difficult to align the sash arm with the window sash during installation of the window assembly.

Usually the sash arm is received in a longitudinal channel of the sash profile, which thus determines its position accurately in a transverse direction (i.e. in a direction roughly parallel to the member openingiclosing direction). However, the installer has to determine the correct longitudinal position for the sash arm. The hinge needs to be in an open condition when the sash is being slid into place, and this can make it difficult to align the edges of the window so that it will close properly in the frame.

The procedure for checking, and readjusting the sash position is tine consuming, and the effectiveness of the window seal can be reduced if the sash is misaligned.

According to a further aspect of the invention, there is provided a friction hinge for supporting a sash between a closed position and an open position, the hinge comprising a fixed member and a sash arm for supporting a sash, the fixed member and sash arm being linked by an arrangement of link arms in use, the sash arm comprising means for enabling positioning of a sash edge relative to the proximal end of the sash arm, said means comprising a stop, the stop being a projecting extension of the sash arm against which an edge of the sash may abut, the stop being removably attachable to the sash arm. The means for enabling positioning of the sash is a stop or abutment, which in use, provides a stop against which the sash is placed during installation. Advantageously, the installer does not need to check and readjust the sash alignment, but can quickly install the sash in the correct position.

Preferably the stop is removably locatable at two or more different positions along the longitudinal axis of the sash arm. This allows the sash to be aligned at two or more different1 pre-determined positions along the longitudinal axis of the sash arm, as required for different types of hinges.

Preferably the sash arm has engagement means for removably engaging the stop, the sash arm having engagement means at two or more different positions along the longitudinal axis of the sash arm. Preferably the stop comprises at least one extending protrusion, the sash arm having at least one corresponding hole in which said at Least one extending protrusion is removably receivable. Preferably the stop comprises first and second extending protrusions, the sash arm having a first set of corresponding first and second holes in which said first and second extending protrusions of the stop are respectively removably receivable. Preferably the sash arm further comprises a second set of corresponding first and second holes in which said first and second extending protrusions of the stop are removably receivable, the second set beingS located at a different position along the longitudinal axis of the sash arm from the first set. Preferably the stop is located near to the proximal end of the sash arm.

According to a further aspect of the invention there is provided a stop for a friction hinge comprising a sash arm coupled to a fixed member by an arrangement of link arms, the stop enabling positive positioning of a sash edge relative to the proximal end of the sash arm, the stop, in use, being a projecting extension of the sash arm against which an edge of the sash may abut, the stop being removably attachable to the sash arm. Preferably the stop comprises at least one extending protrusion, the sash arm having at least one corresponding hole in which said at least one extending protrusion is removably receivable.

According to a further aspect of the invention there is provided a friction hinge for supporting a sash between a closed position and an open position, the hinge comprising a fixed member and a sash arm for supporting a sash, the fixed member and sash arm being linked by an arrangement of link arms in use, the sash arm having means for enabling positioning of a sash edge relative to the proximal end of the sash arm, said means comprising at least one marker against which an edge of the sash may be aligned in use. The at least one marker provides means for aligning the sash on the sash arm during installation. By providing one or more markers on the sash arm, the sash can be aligned in the correct position with regard to the sash arm without the need for an additional stop or abutment attached to the sash arm.

Preferably the sash arm has two or more markers, each marker being at a different position along the longitudinal axis of the sash arm. This allows the sash to be aligned at one or more different, pre-determined positions along the longitudinal axis of the sash arm, as required for different types of hinges.

Preferably the or each at least one marker comprises at least one aperture in the sash arm. The edge of the sash will be visible through said at least one aperture, allowing the edge of the sash to be lined up with the aperture. Alternatively, the or each at least one marker may comprise a visible mark marked on a surface of the sash arm.

Preferably the or each at least one marker comprises at least one aperture, the friction hinge further comprising a stop, in use, the stop being a projecting extension of the sash arm against which an edge of the sash may abut, the stop having at least one extending protrusion, said at least one extending protrusion being removably receivable in said at least one aperture. In this way, said at least one aperture can be used to removably receive a stop. Preferably the stop has first and second extending protrusions, the or each at least one marker comprising first and second corresponding apertures in which the first and second extending protrusions are respectively removably receivable.

Preferably said arrangement of link arms comprises at least a first link arm pivotally coupled, directly or indirectly, to the sash arm and the fixed member in use, the first link arm having at least one indication marker, the or each at least one indication marker being aligned with the or each at least one marker of the sash arm when the sash arm is substantially perpendicular to the fixed member. The indication marker provides an additional mark against which the edge of the sash can be aligned.

Preferably the first link arm further comprises a label adjacent to the or each indication marker. The label can indicate the type of hinge to which marker and/or each indication marker corresponds, allowing the installer to select which marker and/or each indication marker to align the sash edge with.

According to a further aspect of the invention there is provided a friction hinge comprising a sash arm coupled to a fixed member by an arrangement of link arms in use, said arrangement of link amis comprising at least a first link arm pivotally coupled, directly or indirectly, to the sash am, and the fixed member in use, the first link arm having means for enabling positioning of a sash edge relative to the proximal end of the sash arm, said means comprising at least one indication marker against which an edge of the sash may be aligned when the sash arm is substantially perpendicular to the fixed member Preferably the first link arm further comprises a label adjacent to the or each indication marker.

A drawback with hinges is that over time the weight of the sash will case the sash to drop on its hinges, such that it no longer aligns with the sash frame correctly when in the closed position. This is a particular problem for top-hung sashes having a hinge mounted to a side of the sash, or having two hinges, one on each side of the sash.

With top-hung windows, the weight of the sash will cause the sash arm to drop relative to the fixed arm, such that on closing the sash, the bottom of the sash may eventually abut the bottom of the sash frame, preventing the sash from closing.

According to a further aspect of the invention there is provided a friction hinge for supporting a sash between a closed position and an open position, the hinge comprising a fixed member and a sash arm for supporting a sash, the fixed member and sash arm being linked by an arrangement of link arms in use, the hinge further comprising first and second contact means, the first contact means being located on the sash arm and the second contact means being located on the fixed member such that the first and second contact means contact one another when the hinge is in the closed position, whereby the sash arm is brought into correct alignment with the fixed member when the hinge is in the closed position. The invention provides an anti-drop feature, to ensure that the sash is aligned correctly in the sash frame when closed.

Preferably the first contact means has a circular shaped body. Preferably the first contact means is rotatably mounted to the sash arm. Preferably the second contact means has a recessed portion, the first contact means engaging a side of the recessed portion when the hinge is in the closed position. Preferably the first and second contact means are made from resilient material. Preferably the first contact means is located at or near the distal end of the sash arm and the second contact means is located at or near the distal end of the fixed member.

Another drawback with window hinges, in particular those for side-hung or side pivoting windows is that the sash arm may sag under the weight of the sash, such that the sash no longer aligns with the sash frame correctly when in the closed position. With side-hung windows, which have a hinge mounted at the bottom of the sash, the weight of the sash wilt tend to cause the distal end of the sash arm to sag relative to the proximal end, such that on closing the sash, the bottom of the sash may abut the bottom of the sash frame, preventing the sash from closing.

According to a further aspect of the invention there is provided a friction hinge for supporting a sash between a closed position and an open position, the hinge comprising a fixed member and a sash arm for supporting a sash, the fixed member and sash arm being linked by an arrangement of link arms, the arrangement of link arms comprising at least a first link arm, the hinge further comprising a riser, the riser comprising a ramped top surface, the riser being located on the at least first link arm or on the fixed member such that the sash arm is contactable with the ramped top surface of the riser when moving towards the closed position. If the sash arm has sagged, the riser acts to lift the sash arm into correct alignment with the sash frame on closing of the sash.

Preferably said at least first link arm has top and bottom surfaces, the top surface facing the sash arm when the hinge is in the closed position, the first link arm having a depressed portion for receiving the riser such that the sash arm is contactable with the ramped portion of the riser when moving towards the closed position. Preferably the riser has an underside, opposing the ramped top surface, the underside having at least one protrusion extending therefrom, the first link arm comprising at least one aperture for receiving the at least one protrusion in use. Preferably the riser comprises a pair of side walls extending away from the underside of the riser, the first link arm being received between the side walls of the riser in use. Preferably the riser is made from a resilient material.

According to a further aspect of the invention there is provided a friction hinge for supporting a sash between a closed position and an open position, the hinge comprising a channel, a sash arm for supporting a sash, a first slider slidably mounted in the channel, and at least one link arm pivotally coupled to the first slider at a first pivot point in use, the slider comprising a plastic body and having top and bottom opposing faces, the bottom face of the slider facing the channel in use, the slider further having at east one recess in its bottom face in which a metal plate is received in use, the slider body and metal plate having corresponding holes in which a pivot pin is receivable.

The metal plate reinforces the slider at the point of pivotal attachment of the link arm with the slider, therefore improving the strength of the attachment of the link arm to theslider. In prior art hinges, the slider is usually made of plastic, such that it slides easily, however it is easy for the link arm to be forcibly detached from a plastic slider by breaking the plastic slider. This invention overcomes this problem, thereby improving security of the hinge. As well as improving security, the slider of the invention is more reliable as it is less likely to break under force, allowing heavier sashes to be carried by the hinge.

Preferably slider has first and second recesses in its bottom face in which first and second metal plates are received respectively, the metal plates each having a hole, the slider having first and second holes which align with the holes of the first and second metal plates respectively in use, in which first and second pivot pins are receivable respectively. Preferably the or each pivot pin comprises a rivet for pivotally attaching a link arm member to the slider. Preferably the slider body is made of glass filled nylon. Preferably the or each metal plate is made of steel.

According to a further aspect of the invention there is provided a slider for a friction hinge which supports a sash between a closed position and an open position, the hinge comprising a channel and a sash arm for supporting a sash, the slider being slidably mountable in the channel, the slider comprising a plastic body and at least one metal plate, the plastic body having top and bottom opposing faces, the bottom face of the plastic body facing the channel in use, the plastic body having at least one recess in its bottom face in which the metal plate is received in use, the slider body and metal plate having corresponding holes in which a pivot pin is receivable to pivotally attach a link arm to the slider.

The sash arm of a friction hinge will include a number of apertures along its length for receiving fixing means for fixing the sash to the sash arm. Where a first link arm is pivotally coupled to the sash arm at the proximal end of the sash arm, it is not possible to position fixing means for fixing the sash to the sash arm at the extreme proximal end of the sash arm as this would interfere with the pivotal coupling of the sash arm and first link arm. The strength of the mounting of the sash to the sash arm is therefore weak at the proximal end of the sash arm. It may be possible for an intruder to insert a crow bar between the sash and sash arm at the weak, proximal end of the sash arm, to try to prize the sash away from the sash arm.

According to a further aspect of the invention there is provided a sash attachment member for a friction hinge, the friction hinge comprising a fixed member and a sash arm for supporting a sash between a closed position and an open position, the sash attachment member extending substantially perpendicular to the sash arm in use, the sash attachment member being attachable to the sash in use.

Advantageously, the sash arm may be fixed to a first edge of the sash and the projecting extension may be fixed to a second edge of the sash, the first and second edges of the sash defining a corner of the sash. This strengthens the mounting of the sash, helping to improve security.

Preferably the sash attachment member includes at least a first sash mounting aperture for receiving fixing means for fixing the sash attachment member to the sash in use.

Preferably the sash attachment member comprises an upstanding portion which projects substantially perpendicular to the sash arm in use and a mounting portion substantially perpendicular to the upstanding portion, the mounting portion being attachable to the sash arm. Preferably the mounting portion has at least one sash arm mounting aperture for receiving fixing means for fixing the sash attachment member to the sash arm in use.

Preferably the mounting portion lies between the sash arm and a link arm in use.

Preferably the mounting portion comprises at least a first sash arm mounting aperture for receiving fixing means for fixing the sash attachment member to the sash arm in use, the sash arm mounting aperture aligning with an aperture in the sash arm and an aperture in a link arm that links the sash arm and fixed member of the hinge in use such that fixing means may be received through the sash arm mounting aperture and the apertures of the sash arm and link arm, fixing the sash attachment member to the sash arm in use and pivotally coupling the sash arm and link arm in use. In this way, the sash can be mounted directly on to the top surface of the sash arm, the mounting portion of the projecting extension lying between the sash arm and link arm in use. The projecting extension can be mounted to the sash arm using the pivot pin/rivet which is used to pivotally couple the sash arm and link arm, therefore no further fixing means is required additionally fix the projecting extension to the sash arm.

Preferably the upstanding portion has a leading edge and a trailing edge, the trailing edge facing in the direction of closure of the sash in use, the upstanding portion comprising a hook-shaped projection on its trailing edge. If an intruder attempts to pull the sash arm and sash open, the hook-shaped projection may engage with an upstanding portion on a fixed member of the friction hinge, preventing further opening of the sash.

According to a further aspect of the invention there is provided a friction hinge for supporting a sash arm between a closed position and an open position, the hinge comprising a fixed member and a sash arm for supporting a sash, the fixed member and sash arm being linked by at least one link arm in use, the friction hinge further comprising a sash attachment member as described above.

Preferably the sash arm has a proximal end and a distal end, the proximal end of the sash arm having a projection and the fixed member having an end portion comprising a first upstanding member, the first upstanding member having an aperture in which the projection of the sash arm is received when the hinge is in the closed position. This improves the strength of the hinge by increasing the thickness of the proximal portion of the sash arm which is receivable in the aperture of the upstanding member when the hinge is in the closed position.

Preferably the sash attachment member further comprises a first projection extending in a proximal direction in use, the projection of the sash attachment member being received in the aperture in the first upstanding member or being positioned adjacent to the first upstanding member when the hinge is in the closed position. This improves security by acting to prevent movement of the sash arm when a lateral force is applied to the sash, perpendicular to the longitudinal axis of the sash arm when in the closed position. The projecting extension may have a first projection that is received in the aperture of the first upstanding member and a second projection that is positioned substantially adjacent to the first upstanding member when the hinge is in the closed position.

Preferably the sash attachment member further comprises a projection corresponding to the projection of the sash arm, the projections of the sash attachment member and sash arm being received in the aperture in the first upstanding member when the hinge is in the closed position. This improves the strength of the hinge by increasing the thickness of the proximal portion of the sash arm which is receivable in the aperture of the upstanding member when the hinge is in the closed position.

A common problem with windows, especially top hung windows, is that the main link arm which supports the greatest portion of the weight of the window when the window is in an open position can buckle under the weight of the window. In the past, people have attempted to make hinges more stable by adding more link arms to the linkage linking the fixed member and the sash arm. However, this increases the cost of the hinge as a further link arm is required. Another way that people have attempted to strengthen and stabilise hinges is to increase the thickness of some or all of the link arms. However, increasing the link arm thickness(es) would increase the overall stack height, and where a particular maximum stack height must be used, it will not be possible to increase the thickness of somelall of the link arms.

Accordng to a further aspect of the invention there is provided a link arm for a friction hinge, the friction hinge supporting a sash between a closed position and an open position and having a fixed member and a sash arm for supporting a sash, the link arm being pivotally coupled directly or indirectly to the fixed member and the sash arm in use, the link arm comprising a planar portion and an overhang portion, the overhang portion extending substantially perpendicular to the planar portion of the link arm. The overhang portion of the link arm increases the strength of the link arm.

Preferably the planar portion and overhang portion are substantially elongate, the longitudinal axis of the planar portion and the overhang portion being substantially parallel. Preferably the planar portion comprises a leading edge and a trailing edge, the overhang portion extending from the leading edge of the planar portion. In this way, the overhang portion faces towards a flange part of the sash which lies adjacent the sash frame when the sash is in the closed position.

Preferably the overhang portion includes a resilient member which compresses against the sash when the sash is in the closed position. Advantageously, the resilient member can compress against a portion of the sash (i.e. a flange part of the sash which lies adjacent the sash frame when the sash is in the closed position) when the sash is in the closed position, forming a seal between the sash and frame.

Preferably the fixed member of the friction hinge comprises a channel, the friction hinge further comprising a first slider slidably mounted in the channel, the link arm being pivotally coupled to the first slider.

According to a further aspect of the invention there is provided a friction hinge for supporting a sash between a closed position and an open position, the hinge comprising a fixed member, a sash arm for supporting a sash, the fixed member and sash arm being linked by a linkage in use, the linkage comprising at least one ink arm in accordance with the above described aspect of the invention, the at least one link arm being pivotally coupled directly or indirectly to the fixed member and the sash ami in use.

In this context the term proximal means located towards the end of the fixed member which the sash pivots about during opening/closing and the term distal means the opposite end of the fixed member.

In this context, the term leading edge means an edge facing in the direction of opening of the sash and the term trailing edge means an edge facing in the direction of closing of the sash.

In this context, the terms bottom and base with reference to the hinge refer to the parts of the hinge in proximity to the sash frame in use, and the term top refers to parts of the hinge in proximity with the sash in use. It will be undeistcod that the hinge can be used in any orientation however, for example for side-hung or top-hung windows.

Brief Description of the Drawings

Embodiments of the invention will now be described by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a plan view of a prior art friction hinge; Figure 2 is a plan view of an egress hinge, the hinge being partially open, with the sash arm at an angle to the channel; Figure 3 is a plan view of the egress hinge of figure 2, the hinge being in the closed position, part of the sash arm and second link arm having been cut away at the mid portion of the hinge to show the underlying first and third link arms; Figure 4 is a plan view of the egress hinge of figure 2 showing a close-up of the first and third link arms; Figure 5 is a perspective view of the egress hinge of figure 2, a sash being mounted to the hinge and the hinge being mounted in a sash frame; Figure 6 is a perspective view of the egress hinge of figure 2; Figure 7 is a perspective view of the distal end of a second embodiment of an egress hinge, the hinge being partially open, showing a close-up of the proximal end of the hinge with a first end piece mounted to the channel and also showing second and third end pieces, two plates, and a modified first link arm separate from the hinge; Figure 8 is a perspective view of the hinge of figure 7, the first end piece of the hinge being shown separate from the hinge and the second and third end pieces and two plates being shown separate from the hinge; Figure 9 is a perspective view of the hinge of figure 7, the first link arm having been replaced by the modified first link arm; Figure 10 shows a perspective view of a close-up of the proximal end of the hinge of figure 9, the hinge being in the closed position; Figure 1 1A shows a side cross-sectional view of an egress hinge according to a third embodiment of the invention, the hinge being mounted to a sash frame and a sash being mounted to the hinge, the hinge being in the open position and including a floating stay; Figure 11 B shows five views of the floating stay of figure 10, the view comprising a plan view, an underside view, a perspective view, a side view and an end view of the floating stay; Figure 12 is a perspective view of an egress hinge according to a fourth embodiment, showing a close-up of the first and second sliders contacting when the hinge approaches the fully open position; Figure 13 is a cross-sectional perspective view of the hinge of figure 12 showing a cross-section along a plane parallel with the longitudinal axis of the channel and perpendicular to the base of the channel; Figure 14 is a cross-sectional side view of the hinge of figure 12, showing a cross-section along a plane parallel with the longitudinal axis of the channel and perpendicular to the base of the channel; Figure 15 is a cross-sectional side view of the hinge of figure 14, with the hinge in the fully open position; Figure 16 is a plan view cf the hinge of figures 12 to 15 showing the hinge as it approaches the fully open position; Figure 17 is a plan view of the hinge of figure 16 showing the first slider having been moved from its fixed position, towards the distal end of the channel; Figure lOis a perspective view of the hinge of figures 12 to 17, showing a close-up of the restrictor when the hinge is not in the fully open position; Figure 19 is a perspective view of the hinge of 18, showing a close-up of the restrictor, when the hinge is in the fully open position; Figure 23 shows a cross-sectional side view of an egress hinge according to a sixth embodiment of the invention, the hinge being mounted to a sash frame and a sash being mounted to the hinge, the hinge being in the fully open position and including a blocking device; Figure 24 is a cross-sectonal side view of an egress hinge of figure 23 showing a cross-section along a plane parallel with the longitudinal axis of the channel and perpendicular to the base of the channel, showing a close-up view of the blocking device; Figure 25 is a perspective view of the hinge of figures 23 and 24 showing the blocking device in its unreleased configuration; Figure 26 is a perspective view of the hinge of figure 25 showing the blocking device in its released configuration; Figure 27 shows five different views of the blocking device of figures 23 to 26, the view comprising a perspective view, a side view, a top plan view, an underside view an underside perspective view; Figure 28 is a perspective view of an egress hinge according to a seventh embodiment, a sash being mounted to the hinge and the hinge being mounted in a sash frame, the sash arm having a stop attached thereto, the hinge being in the fully open position; Figure 29 is a perspective view of the hinge of figure 28, the stop being shown separate from the hinge; Figure 30 shows four views of the stop of figures 28 and 29, the views comprising a front view, a top view, a side view and a perspective view; Figure 31 is a cross-sectional side view of an egress hinge according to an eighth embodiment of the invention, the hinge being mounted to a sash frame and a sash being mounted to the hinge, the hinge being in the fully open position and showing means for aligning the sash with the sash arm; Figure 32 is a cross-sectional side view of the egress hinge of figure 31, showing a close-up view of the proximal end of the sash arm; Figure 33 is a perspective view of an egress hinge according to a ninth embodiment of the invention, the hinge being mounted to the side of a sash frame, the sash not shown, the hinge being partially open, the sash arm including an anti-drop wheel; Figure 34 is a perspective view of the hinge of figure 33, showing the hinge in the closed position; Figure 35 is a top view of the hinge of figure 33, the hinge being partially open, the sash frame not shown; Figure 36 is a side view of the hinge of figure 35; Figure 37 is a top view of the hinge of figure 33, the hinge being in the closed position and the sash arm being shown in ghost lines so that features underneath are visible; Figure 38 is a perspective view of the hinge of figure 37, the hinge being partially open and the sash arm being shown in ghost lines so that features underneath are visible; Figure 39 shows a perspective view of a hinge according to a tenth embodiment of the invention, the hinge being partially open1 a riser block being shown separate from the hinge; Figure 40 shows the hinge of figure 39, the riser block being mounted to a link arm; Figure 41 shows a side view of the hinge of figure 40, the hinge being closed; Figure 42 shows four views of the riser block of figure 39, the views comprising a top view, a side view1 a front view and a perspective view; Figure 43 is a perspective view of the underside of a hinge according to an eleventh embodiment of the invention, the sliders incorporating metal strengthening plates at the pivot attachment points; Figure 44 is a perspective view of the hinge of the hinge of figure 43, the channel not shown; Figure 45 is a perspective view of the underside of a similar hinge to that of figure 43, showing a close-up view of the proximal end of the hinge; Figure 46 shows three views of a metal plate for the hinge of figures 43 to 45, the views comprising a front view, a side view and a perspective view; Figure 47 shows a perspective view of a hinge according to a twelfth embodiment of the invention, the sash arm having a sash attachment member at its proximal end, the hinge being in the closed position; Figure 48 shows a side view of the hinge of figure 47; Figure 49 shows a close-up view of the proximal end of the hinge of figure 48; Figure 50 shows a perspective view of the proximal end of the hinge of figure 47; Figure 51 shows a perspective view of the distal side of the proximal end of the hinge of figure 47; Figure 52 shows a front perspective view of the sash attachment member of the hinge of figure 47; Figure 53 shows a rear perspective view of the sash attachment member of the hinge of figure 47; Figure 54 shows a front perspective view of distal plate of the hinge of figure 47; Figure 55 shows a plan view of a hinge according to a thirteenth embodiment of the invention, the hinge being in the fully open position, one of the link arms having an overhang portion; Figure 56 shows a close-up perspective view of part of the hinge of figure 55; Figure 57 shows a rear perspective view of the link arm with overhang portion of the hinge of figure 55; Figure 58 shows a front perspective view of the link arm of figure 57; Figure 59 shows a side view of the link arm of figure 57.

Description of the Preferred Embodiments

The present embodiments represent currently the best ways known to the applicant of putting the invention into practice. But they are not the only ways in which this can be achieved, They are illustrated, and they will now be described, by way of example only. Common features between the hinges of the different figures are referenced by common reference numerals.

FiQures 2 to 6 Referring to figure 2, a friction hinge 30 is shown comprises a channel shaped member 32 and a pivoting member or sash arm 34 coupled to the channel shaped member by an arrangement of pivoting link arms or stays. The hinge 30 comprises a first link arm 36, a second link arm 37 and a third link arm 38, which provide a friction hinge movement of the sash arm 34 relative to the channel 32. The first link arm 36 is pivotally coupled at one end to the channel 32 by means of being coupled to a first slider (not visible in figure 2) at pivot point 40, the slider being received in the channel 32. The first link arm 36 is pivotally coupled at its other end to the sash arm 34 at pivot point 41. The third link arm 38 is pivotally coupled at one end to the channel 32 by means of being coupled to the first slider at pivot point 45 and is pivotally coupled at its other end to a mid-point of the second link arm 37 at pivot point 42. The second link arm 37 is pivotally coupled to the channel 32 by means of being pivotally coupled at one end to a second slider 39 at pivot point 43 and at its other end to the sash arm 34 at pivot point 47.

In use, a sash is mounted to the sash arm 34 and the sash arm 34 supports the load of the sash, the sash arm 34 being movable between a closed position in which the sash arm 34 is parallel with the channel 32 and an open position in which the sash arm 34 is at an angle relative to the channel 32 (i.e. an angle of more than 0°).

The first link arm 36 has a hook-shaped end 46, this end of the first link arm 36 being pivotally attached to the first slider. The third link arm 38 also has a corresponding hook-shaped end 48, this end being pivotally attached to the first slider. Referring to figure 3, the hook-shaped ends 46, 48 of the first and third link arms 38, 38 interlockingly engage when the hinge is in the closed position. As the hinge is moved from the closed position towards the open position, the hook-shaped ends of the first and third link arms 36, 38 disengage. In use, as the hinge is moved towards the closed position, the hook-shaped ends 46, 48 of the first and third link arms 36, 38 interlock with one another, helping to pull the sash into the fully closed position as it closes.

Figure 5 shows the friction hinge 30 attached to a fixed frame 11 and sash 13, the sash being open at an angle to the fixed frame.

Referring to figure 20, the third link arm 38 may have a plastic cover 49 that fits over the top of the third link arm 33, the cover 49 projecting over the hooked-end 48 of the third link arm 38. When the hinge is in the closed position, and also when the hinge is partially open, the cover 49 covers both the hooked-end 48 of the third link arm 38 and also the hooked-end 46 of the first link arm 36, such that the booked-ends are protected from debris falling therebetween. The cover 49 also prevents people from catching their fingers between the hooked ends 46, 48.

The ends of the first and third link arms 36, 38 which are pivotally coupled to the first slider need not be hook-shaped, but can comprise any suitable inter-engaging shape. Alternatively, for example, the ends of the first and third link arms 36, 38 which are pivotally coupled to the first slider may each include complementary gear teeth which interengage.

In the embodiment of figures 2 to 6, the first and third link arms are pivotally coupled to a first slider, providing a hinge with an easy-clean feature, however the first and third link arms could of course be pivotally coupled directly to the channel 32.

FiQures 7 to 10 An advantage of having hook-shaped ends on the first and third link arms 36, 38 is that no additional end pieces are required to be fined to the proximal ends of the sash arm and fixed member respectively, in order to help pull in the sash as it closes. This allows additional security features to be provided at the proximal ends of the sash arm and fixed member. Such security features will now be described in accordance with a second main aspect of the invention. It will be understQod that these security features may be employed, in isolation, to a friction hinge without the features of the hinge as described above in relation to figures 2 to 6.

Referring to figures 7 to 10, a second embodiment of the invention is shown, having additional security features at the proximal end of the friction hinge. The proximal end of the sash arm 34 is hook-shaped 50. The proximal end of the channel 32 has an end piece 52 received in the channel. The end piece 52 has a base portion 54, which is slidably received within the channel 32 and can be secured thereto by means of rivets (not shown) which pass through holes 56, 58 in the base portion 54 of the end piece and the channel 58 respectively. The end piece 52 also has an upstanding portion 60, which projects perpendicularly away from the plane of the base portion 54. The upstanding portion 60 includes a substantially rectangular shaped aperture or through-hole 62, which receives the hook-shaped end 50 of the sash arm 34 when the hinge is in the closed position. The upstanding portion 60 with aperture 62 therefore acts as a catch. The engagement of the hook-shaped end 50 of the sash arm in the aperture 62 when the hinge is in the closed position improves security by acting to prevent movement of the sash arm perpendicular to the axis of the channel 32 when a lateral force is applied to the sash, perpendicular to the axis of the channel 32.

The removable end portion 52 is wholly made of plastic, such as glass filled nylon.

Figures 7 and 8 also show second and third end pieces 52a and 52b, which are interchangeable with the first end piece 52. Similar to the first end piece 52, the second and third end pieces 52a, 52b have upstanding members 60a, 60b with apertures 62a, 62b. The aperture 62a of the upstanding member 60a of the second end piece 52a is formed in metal, and is securely attached to the base portion 54a, which is made of plastic. By providing a metal upstanding member 60a (instead of a plastic upstanding member 60, as in the first end piece 52) this provides greater security, as the sides of the metal aperture 62a will be more difficult to break. In the third end piece 52b, as well as a first upstanding member 60b of metal, the end piece 52b has a second upstanding member 64, which is located on a side of the base portion 54b, extending upwards from the plane of the base portion 54b. The second upstanding member 64 is made of metal and has an aperture 64 facing perpendicularly to the aperture 62b of the other first upstanding member 6Db.

Referring to figures 7, 9 and 10, the frst link arm 36 can be interchanged with a modified first link arm 36a having two hook-shaped protrusions 67, 68 on the side edge of the link arm which face away from the sash in use. The first hook-shaped protrusion 67 is received in the aperture 66 of the second upstanding member 64 when the hinge is in the closed position. The base of the first hook-shaped protrusion 67 has a rectangular-shaped pedestal 69 which extends in a plane perpendicularly away from the protrusion 67, the pedestal 69 being received tightly in the rectangular aperture 66 when the hinge is in the closed position. The second upstanding member 64 on the third end piece 52b provides further security, by acting to prevent movement of the sash arm in a direction parallel to the axis of the fixed member. The second hook-shaped protrusion 68 of the link arm 36a also prevents movement of the sash arm in a distal direction, as it would engage against the sides of the second upstanding menber 64 if force were applied to the sash arm in the distal direction.

One or two plates 70, each having a hook-shaped end 70, can optionally be fixed to the proximal end of the sash arm 34 in order to increase the thickness of the hook-shaped end 50 of the sash arm 34, thereby increasing the strength of the hook-end.

The hook-shaped ends of the plates 70 match the shape of the hook-shaped end 50 of the sash arm 34. Referring to figures 9 and 10, a single plate 70 is shown attached to the proximal end of the sash arm 34, however it will be understood that a further plate can be securably attached thereto. The plate(s) 70 are attached to the sash arm 34 by means of pins or rivets 63. Preferably plate(s) 70 are made of metal.

Figures llAandllB Referring to figures 1 1A and 11 B, an embodiment of the invention is shown wherein the friction hinge may be provided with a blocking device (or floating stay') 80.

Referring to figure 118, the floating stay 80 has a plastic body portion 81, which has side wings and is shaped for easy handling by the user. The floating stay 80 also has a magnetic pin 82, which is cylindrical in shape and protrudes from a face of the body portion 81. The pin extends perpendicularly from a face of the body portion 81, extending away from a circular magnetic pedestal 83 at the base of the pin 82: Referring to figure 1 1A, the bottom of the channel 32 of the friction hinge 30 has a plurality of holes 84 along its length. The holes 84 are circular and are sized and shaped to receive the pin 82 of the floating stay 80.

The hinge 30 is an egress type hinge, the second link arm 37 being pivotally coupled at one end to a second slider 39. In a normal opening operation of the window, the first slider 35, to which the first and third link arms 36, 38 are pivotally coupled, is fixed; as the sash 13 is opened, the second slider 39 slides towards the proximal end of the channel, and the sash may be opened up to an angle of substantially 90° to the channel 32. In order to retain the sash at a desired opening angle, the user can insert the pin 82 of the floating stay 80 in one of holes 84. The magnetic pedestal 83 of the floating stay 80 is magnetically attracted to the channel bottom, which is made of ferromagnetic material, retaining the floating stay in position. When secured to the channel 32, the floating stay 80 blocks the channel 32 and prevents the second slider 39 from sliding towards the distal end of the channel 32, preventing the sash from closing. The permanent magnet used for the pin 82 and pedestal 83 must be strong enough that it will securely retain the floating stay in position whilst the second slider 39 bears down on it under the weight of the sash 13. The holes 84 provide the user with a plurality of discrete selectable blocking positions for locating the floating stay, in order to allow the window to be retained open in one of a plurality of discrete angular positions.

Although described here as magnetic, the pin 82 of the floating stay 80 need not be magnetic, as the magnetic pedestal 83 will magnetically engage with the base of the channel 32.

When not in use, the floating stay 80 may be stored on a ferromagnetic plate 85 mounted to the sash frame 11, the magnetic pin 82 and pedestal 83 engaging magnetically with the plate to secure the floating stay to the plate (figure 1 IA shows a second floating stay 80 attached to a plate 85). Alternatively, the ferromagnetic storage plate may be mounted to the sash. The width of the floating stay 80 is such that it can be slidably received in the eurogroove of a sash. The eurogroove is a 16 mm groove located on the edge of a sash and is a standard feature on most PVCu and aluminium sashes (and is usually used for locating window locks).

Instead of a magnetic pin and pedestal, it will be understood that different means for removably securing the floating stay to the channel 34 could be used. For example, the floating stay could have a protruding screw which is receivable in a plurality of screw-threaded holes disposed at different positions along the length of the channel 34.

Figures l2to 17 Referring to figures 12 to 19, a fourth embodiment of the invention is shown, relating to the easy-clean" feature of the hinge. The hinge is of the same type as shown in figures 2 to 1IB, except that the sash arm 34 shown in figures 16 and 17 is shortened. Referring to figure 16, the hinge has a first slider 35, to which two link arms 36, 38 are pivotally coupled and a second slider 39, to which a further link arm 37 is coupled. The hinge is an egress, easy-clean hinge, the first slider being fixed in normal operation, but having means for release, so that it can be moved distally along the channel, allowing better access to the front of the sash from indoors, for ease of cleaning.

At the distal end of the first slider 35, there is an easy-clean restrictor 90, shown in figures 12 to 19. The channel 32 has a bottom, two side walls, and a pair of inward facing lips 31, one at the top of each side wall. Towards the proximal end of the channel, each lip 31 has an opposing recess 91, forming a rectangular cut-out region 91a in the inward facing lips 31. In normal operation, edges of the body of the restrictor 90 engage with recesses 91 in the channel lips 31, such that that first slider 35 is prevented from moving within the channel. Referring to figure 13, a coil spring 92 is disposed between the underside of the restrictor 90 and the base of the channel 32, the spring 92 urging the restrictor 90 away from the base of the channel.

The restrictor 90 is a separate piece from the first slider 35, and is coupled to the first slider 35 b! a brace 93 which is integral with the first slider 35 and which passes over the restrictor 90, between a rectangular body portion and a sloped portion 94 of the restrictor 90. The restrictor 90 is translationally movable relative to the first slider 35, towards and away from the base of the channel 32, the restrictor 90 being coupled to the first slider 35 such that it is carried by and movable with the first slider as the slider moves along the longitudinal axis of the channel 32. In order to release the first slider 35, the restrictor 90 must be depressed, against the force of the biasing spring 92, to disengage the restrictor 90 from the recesses 91 and allowing the restrictor 90 to slide underneath the lips 31 of the channel.

At the distal end of the restrictor 90, the restrictor has a sloped portion 94, the sloped portion having an upper surface 94a that slopes down, towards the base of the channel 32 and towards the distal end of the hinge (as used herein, the temi downwards corresponds to a direction towards the base of the channel and upwards corresponds to a direction away from the base of the channel, however it will be understood that the channel can be placed at the base of a window frame, for a side-hung window, or at the side of a window frame, for a top-hung window).

The proximal end of the second slider 39 includes a sloped region 96, the sloped portion having a lower surface 96a that slopes upwards, away from the base of the channel and towards the proximal end of the hinge.

During opening of the hinge, the second slider 39 slides towards the proximal end of the channel 32. Once the hinge has reached its fully open position (usually the fully open position will be the position where the sash arm 34 is angled substantially at 90° to the channel 32, however the hinge may be adapted such that the sash arms maximum angle of opening relative to the channel 32 is less than 90°) the proximal end of the second slider 39 contacts with the restrictor 90. Referring to figures 14 and 15, as the second slider 39 contacts the downward sloping region 94 of the restrictor 90, the sloped region 96 of the second slider 39 forces the restrictor 90 towards the base of the channel. Referring to figure 15, once the upward sloping region 96 of the second slider 39 fully overlies the downward sloping region 94 of the restrictor 90, the proximal end of the second slider 39 abuts the brace 93, and the restrictor 90 is fully depressed towards the base of the channel. Referring to figure 17, the user can then apply force to the first slider 35 to move it towards the distal end of the channel, allowing access to the outer surface of the window from inside for ease of cleaning.

In prior art hinges, release of the restrictor 90 would have been carried out manually by the user. In the hinge shown herein, release of the restrictor 90 occurs automatically when the hinge is in its fully open position.

On closing the hinge, the arrangement of link arms 36, 37, 38 causes the second slider 39 to move towards the distal end of the channel 32 and the first slider 35 to move towards the proximal end of the channel, carrying the restrictor 90 along with it. The restrictor 90 and the second stider 39 do not interlockingly engage when the easy-clean feature is activated, therefore on closing of the sash, the restrictor 90 and the second slider 39 can freely move apart from one another, as the first 35 and second 39 sliders move apart from one another. The upward sloping portion 96 is therefore released from contact with the downward sloping portion 94, the spring 92 urging.the restrictor 90 against the lips 31 of the channel. When the hinge is in the closed position, the first slider 35 abuts the end piece 52 at the proximal end of the channel, and is prevented from further proximal movement. At this position, the restrictor 90 aligns and engages with the recesses 91 in the lips 31 of the channel, as shown in figures 12, 13 and 14, and the first slider 35 is fixed in position, preventing movement towards the distal end of the channel. In this way, closing of the sash automatically returns the first slider 35 to its fixed configuration.

The first slider 35 may be fitted with a screw fixing or some other fixing (not shown) for reversibly locking the first slider in position in the channel 32 to prevent the first slider 35 from sliding within the channel 32. However, if it is desired to release the first slider 35, in order to allow the easy-clean functionality described above to operate, the screw fixing or other fixing can be loosened to release the first slider 35 so that it can slide within the channel 32.

The restrictor 90 is removably attachable to the first slider 35, such that it can be used as an optional feature for the hinge.

Figures 20 to 22 Referring to figures 20 to 22, a fifth embodiment of the invention will be described, which relates to opening restrictors fol hinges, which prevent a window from opening beyond a certain angular position. Figures 20 to 23 show an egress hinge of the type shown in figures 2 to 6. Referring to figure 20, the second slider has a blocking device or opening restrictor 100, which controls the extent to which the hinge can be opened. The opening restrictor 100 is carried by and movable with the second slider 39. The restrictor 100 comprises a T-shaped member which is coupled to the distal end of the second slider 39 by means of a pin or screw 101 on the proximal end of the restrictor 100, which is received in a corresponding hole 102 in the second slider 39. In use, the pin 101 extends perpendicularly away from the plane of the bottom of the channel 32. The head 103 of the T-shaped restrictor 100 is substantially square, the head pointing toward the distal end of the hinge when the restrictor 100 is coupled to the second slider 39.

The head of the T-shaped restrictor 100 is capable of engaging with a suitable pair of opposing recesses 104 provided in the lips 31 of the channel 32, to block movement of the second slider 39 and hence to block opening or closing of the hinge. The opposing recesses 104 provide a cut-out region 104a in the lips 31 of the channel. A coil spring 105 is disposed between the underside of the head 103 of the restrictor and the base of the channel 32, the spring 105 urging the restrictor away from the base of the channel. As can be seen from figure 22, the restrictor 100 can be pushed downwards, towards the base of the channel, to disengage the head 103 of the restrictor from the proximal edges of recesses 104, and hence to allow the second slider 39 to move so that the hinge can be opened or closed.

A permanent magnet 106 is attached to the underside of the head 103 of the restrictor 100 and is disposed between the underside of the head 103 of the restrictor and the base of the channel 32. When the head 103 of the restrictor is engaged in the cut-out region, the spring 105 urges the head 103 away from the base of the channel and the magnet 106 is spaced away from the base of the channel. During release of the restrictor 100, the user manually pushes the head 103 of the restrictor 100 towards the base of the channel, at which point the permanent magnet 106 contacts the base of the channel and magnetically engages therewith. Suitably, the bottom of the channel is made of a ferromagnetic material.

The magnetic attraction between the magnet 106 and the base of the channel overcomes the biasing force of the spring 105, and the restrictor 100 is retained in its depressed position, in engagement with the base of the channel. The user can therefore move the sash beyond its initial angular position as shown in figure 20 by first depressing the restrictor 100, and then by applying force to the sash. Unlike with prior art opening restrictors, there s no need to slide the restrictor passed the cut-out region, whilst also depressing the restrictor, in order to open the window beyond the restricted opening position.

The base of the channel 32 has an oval shaped void or aperture 108 located at the proximal end of the cut-out region 104a. Referring to figures 21 and 22, the aperture extends partially into the cut-out region. After the restrictor has been released from engagement with the cut-out region 104a and the window has been opened beyond its restricted opening position, during closing of the hinge, the second slider 39 will then slide towards the distal end of the channel 32. As the restrictor 100 slides over the aperture 108, the magnet 106 is no longer magnetically attracted to the base of the channel, and the spring 105 biases the restrictor 100 upwards away from the bottom of the channel. The restrictor head 103 then engages with the recesses 104 in the lips 31 of the channel, preventing the hinge from being open or closed. Therefore, by sliding the restrictor 100 over the aperture 108, the restrictor 100 is detached from its engagement with the base of the channel, and can return to its restricted position, engaging the cut-out region in the lips of the channel.

It will be understood that the aperture 108 could be located distally or proximally of the cut-out region as desired.

Further cut-out regions in the lips of the channel can be provided, each cut-out region having an associated aperture in the base of the channel, to provide further restrictor positions for the sash.

The restrictor 100 is removably attachable to the second slider 39, such that it can be used as an optional feature for the hinge.

Figures 23 to 26 A sixth embodiment of the invention will be described with reference to figures 23 to 27, Figures 23 to 27 show an egress hinge similar to that shown in figures 2 to 22, however the second slider 39 has a closing restrictor or blocking device 120 attached to its distal end. The blocking device 120 is carried by and movable with the second slider 39. Referring to figure 27, the blocking device is roughly T-shaped, having a head portion 121 and a leg portion 122 extending away from the head portion. The leg portion 122 has an aperture 123a in which a screw 123 with an enlarged head 123b is threadedly received. The screw 123 is attached to the leg portion 122 such that the screw head 123b is not adjacent the top surface of the leg portion 122, but is displaced away somewhat from the top surface of the leg portion 122. In use the blocking device 120 is coupled to the second slider 39 by means of screw 123 being received in a hole 124 in the second slider 39 and the screw 123 being threadedly engaged to the blocking device 120 as described above, Hole 124 is deeply countersunk. Since the screw head 123b is displaced away somewhat from the top surface of the leg portion 122, the screw 123 can move up and down translationally within hole 124.

The head portion 121 of the blocking device 120 has side wings 126, which are chamfered, their upper surfaces sloping relative to a planar mid portion 127 of the head portion 121. The sloping side wings 126 slope towards the base of the blocking device 120 and towards the leg portion 122. When the blocking device 120 is attached to the second slider 39, upper surfaces of the side wings 126 slope downwards towards the base of the channel and in the direction of movement of the second slider 39 during opening of the sash (i.e. towards the proximal end of the channel and away from the trailing edge 128 of the blocking device 120).

The lips 31 of the channel have a first cut-out region 104a near the distal end of the channel, and a second cut-out region 109a located between the distal and proximal ends of the channel. Each cut-out region comprises a pair of opposing recesses 104, 109 in the inward facing lips 31 of the channel. The trailing edge 128 of the head portion 121 of the blocking device 120 is capable of engaging with the recesses 104, 109 in the lips 31 of the channel, to block movement of the second slider towards the distal end of the channel, and hence to block movement of the hinge from an open position to the closed position.

A coil spring 129 is disposed between the underside of the head portion 121 of the blocking device and the base of the channel, the spring 129 urging the blocking device 120 away from the base of the channel. As can be seen from figure 26, the blocking device 120 can be pushed downwards, towards the base of the channel, to disengage the trailing edge 128 of the restrictor from the recesses 109, and hence to allow the second slider 39 to move towards the distal end of the channel. When the blocking device 120 is pushed towards the base of the channel, both the blocking device 120 and the screw 123 move translationally, relative to the second slider 39, towards the base of the channel.

In use, the hinge may be opened freely to its fully open position, in which the sash arm is angled at around 90° to the channel. The blocking device 120 slides passed the first cut-out region 104a, the side-wings 126 of the bloàking device being sloped, as previously described, such that they do not engage with the recesses 104. The blocking device 120 then reaches the second cut-out region 109a, wherein if the user releases grip of the sash, the trailing edge 128 of the blocking device 120 will engage the recesses 109, blocking the second slider 39 from moving towards the distal end of the channel, hence blocking the sash from moving to the closed position. The user can manually depress the blocking device 120 in order to release the blocking device 120 from engagement with the recesses 108. This releases the second slider 39, thereby allowing the second slider 39 to move towards the distal end of the channel. As the second slider 39 moves toward the distal end of the channel, the blocking device 120 reaches the first cut-out region 104a, wherein the trailing edge 128 of the blocking device will engage the recesses 104, retaining the sash in a partially open position. Again, the user can manually depress the blocking device 120 in order to release the blocking device from engagement with the recesses 104. The sash can then be moved to the closed position.

The opposing recesses 109 are located at a position between the distal and proximal ends of the channel, such that when the blocking device 120 is engaged in the recesses, the sash is retained in the fully open position, with the sash arm angled at around 90° to the channel.

It will be understood that the recesses 109 can be located at a position closer to the distal end of the channel 32, such that the sash can be retained in a different angular position relative to the channel. It will also be understood that a single cut-out region may be provided, Alternatively, a plurality of cut-out regions may be provided, in order to allow the sash to be retained open in a plurality of pre-determined angular positions.

The blocking device 120 is removably attachable to the second slider 39, such that it can be used as an optional feature for the hinge.

FiQures 28 to 30 A seventh embodiment of the invention will be described with reference to figures 28 to 30, which show a further embodiment of the invention. Figures 28 to 30 show an egress hinge of a similar type to that shown in figures 2 to 6 (although it will be understood that this aspect of the invention would be equally suitable for other types of hinges). Referring to fJgure 28 a stop or abutment 130 is shown attached to the sash arm 34 of the hinge. Referring to figure 29, the stop 130 is shown detached and separate from the sash arm 34.

Referring to figure 30, the stop 30 comprises a planar, panel section 131, having a first extending protrusion 132 and a second extending protrusion 133, extending away from the panel section 131. The first extending protrusion 132 has an oblong shaped cross-section, with an opposing flat face and an opposing curved face. The second extending protrusion 133 has a circular cross-section.

Referring to figure 4, the sash arm has first and second set holes 134, 135 in which the first and second extending protrusions 132, 133 of the stop 130 can be received.

Each set of holes comprises two holes. The first set of holes 134 comprises a circular hole 134a and an oblong shaped hole 134b. The second set of holes 135 comprises a circular hole 135a and an oblong shaped hole 135b. The oblong holes 134b, 135b and the circular holes 134a, 135a are shaped to removably receive the first and second extending protrusions 132, 133 of the stop 130 respectively. The oblong holes 134b, 1355 are open slots, formed in the edge of the sash arm 34 whereas the circular holes 134a, 135a are closed holes, which are fully bounded on all sides. The first 134 and second 135 sets of holes are located near the proximal end of the sash arm 34, the first set of holes 134 being displaced a short distance away from the second set of holes 135.

For different types of hinge, it may be necessary to align an edge 1 3a of the sash at different longitudinal positions along the longitudinal axis of the sash arm, the sash edge 13a being the edge that is nearest the proximal end of the hinge. For example, the sash and frame may be adapted for use with a hinge of a particular stack height. Stack heights of 17 mm and 14 mm are commonly used. If a stack height of 17 mm is used for example, then the sash will need to be aligned on the sash arm 34 such that there is a spacing o117 mm between the sash edge 13a and the corresponding frame part. During installation of the window assembly, stop 130 is inserted into the first or second set of holes 134, 145 on the sash arm 34, depending on where the sash edge 13a is to be aligned for the particular type of hinge being used. The fixed channel 32 would then normally be fitted firstly to the sash frame 11. Thereafter, the sash 13 would be aligned with the distal end of the sash arm 34, in register with the channel 136 on the sash, and the sash advanced in the direction of arrow 137 in figure 28. When the sash reaches its correct position relative to the sash arm 34, the stop 130 abuts the sash, edge iSa, thereby preventing further movement. The removable stop 130 provides a simple, yet highly effective means of positively aligning the sash 13 relative to the sash arm 34. Since the stop 130 is removably attachable to the sash arm 34, use of the stop 130 is optional. Furthermore, since more than one set of holes 134,135 is provided in the sash arm 34 for receiving the stop 130, means are provided for aligning the sash 13 to the correct position relative to the sash arm 34 depending on the type of hinge being used.

Figures 31 to 32 Referring to figures 31 and 32 an eighth embodiment of the invention will be described. Instead of using the stop 130 as a filling guide, an aperture 134b, 135b from each of the first and second sets of apertures can be used to aid alignment of the sash with respect to the longitudinal axis of the sash arm 34. Figures 31 and 32 show an egress hinge of the type shown in figures 28 to 30. It will be seen from figures 31 and 32 that the edge of the sash 13a can be lined up with the oblong aperture 134b, 135b from the first 134 or second 135 set of apertures at the proximal end of the sash arm 34. During installation, with the hinge open, the installer can advance the sash in the direction of arrow 137 until the edge 13a of the sash aligns with one of the oblong aperture slots 134b, 135b in the sash arm 34.

The installer can selectively align the edge 13a of the sash with the correct oblong aperture 134b, 135b, depending on the type of hinge being used. When viewed looking towards the top surface of the sash arm (i.e. the surface that faces away from the sash) the edge of the sash 13a can be viewed through the oblong apertures 134b, 135b. The oblong apertures 134b, 135b are effectively being used as markers for easy alignment of the sash.

Figures 31 and 32 show an additional feature that can aid installation of the sash.

The first link arm 36 has first and second lines or indication markers 137, 136 marked near the end of the first link arm 36 that is pivotally coupled to the sash arm 34. The indication markers 137, 138 may be visible lines marked on the, first link arm 36, or may be indentations in the surface of the first link arm 36. Adjacent each indication marker 137, 138 is a label 139, 140 marked on the first link arm 36, indicating the type of hinge each indication marker relates to. In this particular example, the first indication marker 137 can be used to indicate the position to which the sash edge should be aligned if using a hinge of stack height 14 mm (therefore the first indication marker 137 is labelled 14'), and the second indication marker 138 can be used to indicate the position to which the sash edge should be aligned if using a hinge of stack height 17 mm (therefore the second indication marker 136 is labelled 17').

The first and second indication markers 137, 138 are positioned on thefirst link arm 36 such that when the hinge is in the fully open position (with the sash arm substantially perpendicular to the channel 32) the first indication marker 137 aligns with the first oblong aperture 134b and the second indication marker 138 aligns with the second oblong aperture 135b. When the hinge is in the fully open position, the first and second indication markers 137, 138 lie over the first and second oblong apertures 134b, 135b respectively. During installation, when the sash is fully open, the installer can refer to the labels 139,140 against the indicótion markers 137, 138 to indicate which oblong aperture 134b, 135b on the sash arm 34 to align the edge 13a of the sash with.

It will be understood that the oblong aperture slots 134b, 135b can be used to align the sash without provision of a stop 130. It will also be understood that it is not necessary to provide indication markers 137, 138 or labels 139, 140 on the first link arm 36, and that the sash could be aligned using only the oblong aperture slots 134b, 135b. It will also be understood that it is not necessary to provide oblong apertures 134b, 135b, and that the sash could be aligned against the indication markers 137, 138 by sight.

Elpures 33 to 38 Referring to figures 33 to 38 a ninth embodiment will be described. Figures 33 to 38 show an egress hinge similar to that of figures 2 to 32, Mounted to the distal end of the sash arm 34 is an anti-drop wheel 141. The wheel 141 is rotatably mounted to the sash arm 34, about a pivot point 142, the wheel 141 being mounted on the surface of the sash arm that faces away from the sash in use. The wheel 141 has a circular shaped body and is made of resilient material.

Mounted to the distal end of the channel 32 is a wheel engagement piece 144, which is made of resilient material. The wheel engagement piece 144 has two holes through which screws or rivets are receivable, in order to mount the wheel engagement piece 144 to the channel 32. The wheel engagement piece 144 has a flat portion 145 and a raised portion 146, which extends away from the channel 32 when the wheel engagement piece is attached to the channel. The raised portion 146 has a planar side wall 147, directed towards the plat portion 145.

In use, when closing the sash, the side of the wheel 141 contacts or engages the planar side 147 of the raised portion 146 on the wheel engagement piece 144. This forces the sash arm 34 towards the proximal end of the hinge, bringing the sash arm 34 into correct alignment with the channel 32 when the hinge is in the closed position. In the closed position, the wheel 141 lies adjacent the flat portion 145 of the wheel engagement piece 144. In this way, despite dropping of the sash arm relative to the channel due to the weight of the sash, the sash can be closed without the sash abutting the sash frame.

Figures 39 to 42 Referring to figures 39 to 42, a tenth embodiment of the invention will be described.

Figures 39 to 42 show an egress hinge similar to that of figures 2 to 6. The hinge includes a riser block 150, which mounts to the second link arm 37 in use. The riser block 150 has a ramped top surface, the top surface sloping away from a peak centre-line having a longitudinal axis parallel to the axis of the channel 32, towards the base of the channel. The riser block 150 has four cylindrical protrusions extending away from its underside, which are receivable in four corresponding holes 153 in the second link arm 37. The riser block 150 also has a pair of side walls 154 extending away from its underside.

The second link arm 37 has a depressed portion 156 shaped to receive theriser block 150. The riser block 150 is mounted on the second link arm 37 such that the protrusions 152 are received in the respective holes 153 in the depressed portion 156 of the second link arm 37 and the sides of the second link arm 37 being tightly received between the side walls 154 of the riser block.

The first 36, second 37 and third 35 link arms are arranged such that the third link arm 37 lies over the first and second link arms when the hinge is in the closed position.

In use, during closing of the hinge, if the distal end of the sash arm 34 has sagged due to the weight of the sash, the underside of the sash arm 34 will contact the ramped top surface of the riser block 150, lifting the sash and bringing the sash into correct alignment relative to the frame.

Figures 43 to 46 Referring to figures 43 to 46. an eleventh embodiment of the invention will be described. Figures 43 to 46 show an egress hinge similar to that shown in figures 2 to 42. Referring to figure 44, the hinge is shown from the underside of the channel 32, the channel 32 not being shown in the figure, such that the underside of the first slider 35 is visible. The first slider 35 is made of glass filled nylon, such that it slides easily against the channel 32. The underside of the first slider 35 that faces the base of the channel in use has first and second rectangular recesses 161, 162. In use, a rectangular metal plate 163 is received in each rectangular recess 161, 162.

Each metal plate 163 has a central hole 164, which lines up with a corresponding hole in the first slider 35, through which a pivot pin can pass. The first link arm 36 is pivotally attached, using a pivot pin 167, to the first slider 35 and to the metal plate 163 in the first recess 161. The third link arm 38 is pivotally attached, using a pivot pin 167, to the first slider 35 and to the metal plate 163 in the second recess 162.

The metal plates 163 improve security for the hinge, by strengthening the attachment of the link arms to the slider, such that it is difficult to forcibly detach the link arms from the slider.

Similarly, the second slider 39 has a rectangular recess in its underside 165, in which is received a metal plate 163. The second link arm 37 is pivotally mounted to the second slider 39 and metal plate 163 using a pivot pin 167 that passes through a hole in the second slider 39 and a corresponding hole 164 in the metal plate 163.

Referring to figures 43 and 45, the underside of the channel has apertures 166 for the purpose of allowing the installer to view the metal plates 163 before installation of the hinge.

Figures 47to 54 Referring to figures 47 to 54, a twelfth embodiment will be described. Figures 47 to 54 show an egress hinge similar to that of figures 2 to 46. Referring to figure 47, there is a corner plate or sash attachment member 170 located at the proximal end of the sash arm 34. Referring to figures 52 and 53, the sash attachment member has an upstanding portion 170a, which extends substantially perpendicular to the sash arm 34 when mounted and a mounting portion 170b, which is substantially parallel to the sash arm when mounted. The mounting portion 170b has a circular aperture 171 for receiving fixing means for fixing the projecting extension to the sash arm 34. The upstanding portion 170a has two circular apertures 172, each for receiving fixing means 176 for fixing the sash attachment member to a sash (not shown).

Referring to figure 51, in use, during assembly, the sash attachment member 170 is positioned such that the mounting portion 170a lies between the sash arm 34 and first link arm 36. The circular aperture 171 in the mounting portion 170b aligns with corresponding circular apertures in the proximal end of the sash arm 34 and first link arm 36, such that a rivet 173 can pass through the apertures in the sash arm 34, projecting extension 170 and first link arm 36. Rivet 173 fixes the projecting extension 170 to the sash arm 34 and also pivotally couples the sash arm 34 and first link arm 36 about pivot point 41. A first edge of the sash is fixed to the sash arm 34 by means of screws passing through a plurality of holes 175 in the sash arm 34. A second edge of the sash, perpendicular to the first edge of the sash, is also fixed to the sash attachment member 170 by means of screws or rivets 176 passing through each circular aperture 172 in the upstanding portion 170a. By employing the sash attachment member 170, the means for fixing the hinge to the sash extends around a corner of the sash, stabilising and strengthening the attachment of the sash to the hinge.

Referring to figure 52, the sash attachment member 170 has a hook-shaped projection 177 which extends in the proximal direction when mounted. Referring to figure 50, the sash arm 34 has a hook-shaped end 50 at its proximal end 34 (similar to the hook-shaped end 50 of the proximal end of the sash arm 34 as described in relation to figures 7 to 10). The hook-shaped projection 177 of the sash attachment member 170 matches the shape of a hook-shaped end 50 of the proximal end of the sash arm 34. The hook-shaped projection 177 and the hock-shaped end 50 lie parallel with one another, with the hook-shaped projection 177 above the hock- shaped end 50, and with their boundary edges aligned when assembled. The hook-shaped projection 177 increases the thickness of the hook-shaped end 50, thereby increasing the strength of the hook at the proximal end of the sash arm 34.

The proximal end of the channel 32 has an end piece having an upstanding portion or catch 60, which projects perpendicularly away from the plane of the channel 32.

The upstanding portion 60 includes a substantially rectangular shaped aperture 62 comprising a through-hole in the upstanding portion 60. Referring to figure 50, in use, when the hinge is in the closed position, the hook-shaped projection 177 of the sash attachment member 170 and the hook-shaped end 50 of the sash arm 34 are received in aperture 62. The engagement of the hook-shaped projection 177 and hook-shaped end 50 in the aperture 62 when the hinge is in the closed position improves security by acting to prevent movement of the sash arm perpendicular to the axis of the channel 32. The plane of each of the hook-shaped projection 177 of the sash attachment member 170 and the hook-shaped end 50 of the sash arm 34 is parallel with the plane of the sash arm in use. The hook-shaped projection 177 and hook-shaped end 50 are shaped such that each have a curved end that would engage with the upstanding portion 60 (i.e. the inner edge of aperture 62) if the sash arm 34 is forced in the direction of the open position.

Referring to figure 52, the sash attachment member 170 has a projecting part 178 extending away from the trailing edge of the sash attachment member 170 (the trailing edge being the side which faces in the direction of closure of the sash). The projecting part 178 has a bend such that the projecting part 178 forms a hook having a hook end directed towards the proximal end of the hinge in use. If an intruder attempts to pull the sash arm and sash open, the hook-shaped projection may engage with the upstanding portion 60 on the fixed member of the friction hinge, preventing further opening of the sash.

The sash attachment member 170 has a through-hole 179 in the upstanding portion llOa. A distal plate 180 is mounted parallel with the upstandihg portion 170a of the sash attachment member 170 and the distal plate 180 is located in a recess in the distal side of the sash attachment member 170. During assembly, the sash is pushed up against distal plate 180 and sash attachment member 170, and the sash is fixed to both the sash arm 34 and the sash attachment member 170, thus holding the distal plate 180 in place, between the sash and the sash attachment member 170. Referring to figure 54, the distal plate 180 has a hook-shaped protrusion 182, extending away from the proximal face of the distal plate 180 in use. The distal plate 180 has a first raised portion 183 at the base of the hook-shaped protrusion 182, the first raised portion 183 corresponding in shape to the through-hole 179 in the upstanding portion 170a, such that the first raised portion 183 is received tightly in the through-hole 179 in use. The distal plate 180 has a second raised portion 184 which is rectangular in shape. When assembled, the second raised portion 184 is received in a corresponding rectangular shaped aperture 165 in the sash attachment member 170, in order to help locate the distal plate 180 in position adjacent the sash attachment member 170. In use: when assembled, the hook- shaped end 50 of the proximal end of the sash arm 34 passes through the through-hole 179 in the upstanding portion 170a. In use, the hook-shaped end 50 lies above the hook-shaped projection 177 of the sash attachment member 170 and under a recess 181 in the bottom edge of the distal plate 160.

Fjgures 55 to 59 Referring to figures 55 to 59, a thirteenth embodiment will be described. Figures 55 to 60 show an egress hinge similar to that of figures 2 to 54, however the second link arm 37' (the longest link arm) differs from that shown in the embodiments of figures 2 to 54 in that it has a planar portion 37a and an overhang portion 37b. The overhang portion 37b extends from the leading edge of the second link arm 37', substantially perpendicular to the planar portion 37a. Referring to figures 57 and 60, an elongate piece of resilient material 190 is disposed on the leading face of the overhang portion 37ft The resilient material 190 may be detachable from the second link arm 37', therefore use of the resilient material is optional.

The overhang portion 37b increases the strength and stability of the hinge, making the hinge such as that shown in figures 55 and 56, for example, strong enough to hold a 30 kg sash, supported as a top-hung window with a binge on either side of the sash, open for about 20 minutes in the fully open position (with the sash perpendicular to the sash frame), without the second link arm buckling. This would therefore allow the window to be stably held open for long enough for several people to escape through the window in the event of a fire.

In use, the overhang portion 37b faces towards a flange part of the sash (not shown) that faces towards the sash frame when the sash is in the closed position. In use, the resilient material 190 compresses against the flange part of the sash, creating a seal between the sash and the frame. Most windows have gasket seals disposed on the sash, which compress against the sash frame when the sash is in the closed position, however these often do not form a tight seal, and the resilient material 190 on the second link arm 37' therefore provides a further seal.

Figures 2 to 59 show egress hinges, however it will be understood that many of the features of the described invention can be used with other types of hinges, such as easy-clean type hinges or non-egress hinges such as the type shown in figure 1.

it should be noted that embodiments of the inventions have been described invention have been described herein by way of example only, and that modifications can be made within the scope of the claims. It should be further noted that each of the many advantageous features described above may be employed in isolation, or in combination with any one or more other features.

Claims

Claims 1. A friction hinge for supporting a sash between a closed position and an open position, the hinge comprising a fixed member, a sash arm for supporting a sash, the fixed member and sash arm being linked by a linkage in use, the linkage comprising at least a first link arm pivotally coupled directly or indirectly to the fixed member and the sash arm, a second link arm pivotally coupled directly or indirectly to the fixed member and the sash arm, and a third link arm pivotally coupled directly or indirectly to the fixed member and the second link arm in use, a first end of the first link arm and a first end of the third link arm being shaped such the said first ends of the first and third link arms interlockingly engage with one another when the sash is in the closed position.
2. A friction hinge according to claim 1 wherein said first end of the first link arm is hook-shaped and said first end of the third link arm is correspondingly hook-shaped, such that the hook-shaped ends of the first and third link arms interlock when the sash is in the closed position.
3. A friction hinge according to claim I wherein said first end of the first link arm and said first end of the third link arm comprise complementary gear teeth, the gear teeth of said first ends of the first and third link arms interlocking in the closed position.
4. A friction hinge according to any preceding claim wherein the fixed member comprises a channel in which a sflder can slide, 5. A friction hinge according to claim 4 wherein the friction hinge further comprises at least one slider slidable in the channel.6. A friction hinge according to claim 4 or 5 wherein the friction hinge further comprises a slider slidable in the channel, the first and third rink arms being pivotally coupled to the slider in use.7. A friction hinge according to claim 4 wherein the friction hinge further comprises a slider slidable in the channel, the second link arm being pivotally coupled to the slider in use.8. A friction hinge according to claim 4 wherein the friction hinge further comprises first and second sliders, each slider being slidable in the channel, the first arid third link arms being pivotally coupled to the first slider and the second link ami being pivotally coupled to the second slider in use.9. A friction hinge according to any preceding claim, the sash arm having a proximal end and a distal end, the proximal end of the sash arm having a projection and the fixed member having an end portion comprising a first upstanding member, the first upstanding member having an aperture in which the projection of the sash am, is received when the hinge is in the closed position.10, A friction hinge for supporting a sash between a closed position and an open position, the hinge comprising a fixed member and a sash arm for supporting a sash, the fixed member and sash arm being linked by an arrangement of link arms in use, the sash arm having a proximal end and a distal end, the proximal end of the sash arm having a projection and the fixed member having an end portion comprising a first upstanding member1 the first upstanding member having an aperture in which the projection of the sash arm is received when the hinge is in the closed position.11. A friction hinge according to claim 9 or 10 wherein the projection of the sash arm is hook-shaped.12. A friction hinge according to any of claims 9 to 11 wherein the aperture comprises a through-hole in the first upstanding member.13. A friction hinge according to any of claims 9 to 12 wherein the aperture is a substantially rectangular shaped hole.14. A friction hinge according to any of claims 9 to 13 wherein the upstanding member is removably attachable to the fixed member.15. A friction hinge according to any of claims 9 to 14 wherein the upstanding member comprises an upstanding portion in which the aperture is located and a base portion which lies parallel to the fixed member in use, the fixed member comprising a support track having a bottom, two side walls and a pair of inwardly facing flanges, the base portion of the upstanding member being slidably receivable between the side walls of the support track, the hinge further including means for releasably securing the base portion to the support track.16. A friction hinge according to any of claims 11 to 15 wherein the hinge further comprises a plate attached to the sash arm in use, the plate having a hook-shaped end corresponding to the hook-shaped end of the sash arm, the hook-shaped ends of the sash arm and plate being received in the aperture when the hinge is in the closed position.17. A friction hinge according to any of claims 9 to 16 wherein the arrangement of link arms comprises at least a first link arm, the fixed member further having a second upstanding member, the second upstanding member having an aperture, the aperture of the second upstanding member facing substantially perpendicularly to the aperture of the first upstanding member in use and being adapted to receive a projection extending from the first link arm or the sash arm when the hinge is in the closed position.18. A friction hinge according to claim 17 wherein the projection extending from the first link arm or sash arm is hook-shaped.19. A friction hinge according to claim 17 or 18 wherein the first link arm has a first hcok-shaped portion, said first hook-shaped portion being received within the aperture of the second upstanding member when the hinge is in the closed position.20. A friction hinge according to claim 19 wherein the first link arm has a second hook-shaped portion adjacent said first hook-shaped portion.21. A kit of parts comprising a friction hinge according to any of claims 9 to 20, the kit further comprising a second, end portion for the fixed member, the first and second end portions being removably attachable to the fixed member, each end portion comprising a first upstanding member having an aperture, the aperture of the first end portion being formed in plastic and the aperture of the second end portion member being formed in metal.22. A blocking device for use with a friction hinge, the blocking device being receivable within a channel of the friction hinge whereby the blocking device can block movement of a rnoveable part of the hinge, the blocking device comprising a body portion for blocking the channel, the blocking device being releasably locatable in one or more selectable blocking positions and being removable from the channel.23. A blocking device according to claim 22 wherein the device further comprises a protruding pin which is receivable within one or more holes in the charnel.24. A blocking device according to claim 22 or 23 wherein the blocking device is releasably engageable in the channel by magnetic engagement.25. A blocking device according to claim 24 wherein the blocking device further comprises a permanent magnet which is releasably engageable with the channel.26. A blocking device according to any of claims 22 to 25 wherein the device is locatable on a ferromagnetic plate mounted to a sash or sash frame, for storing the blocking device when not in use to block the channel.27. A blocking device according to any of claims 22 to 26 wherein the body of the device is shaped such that it is removably receivable within a storage groove on a sash or sash frame, for storing the blocking device when not in use to block the channel.28. A blocking device according to any of claims 22 to 27 for use with a friction hinge, the friction hinge having a channel, a sash arm for supporting a sash, the 3D hinge supporting a sash between a closed position in which the sash arm is substantially parallel to the channel and an open position in which the sash arm is angled relative to the channel, the channel and sash arm being linked by one or more link arms in use, the friction hinge further comprising at least a first slider movable in the channel, at least one link arm being pivotally coupled to the first slider, wherein when the blocking device is located in the channel in a blocking position, movement of the first slider is blocked.29. A blocking device according to claim 28 wherein the blocking device is locatabl! in one or more selectable blocking positions such that when the hinge is in an open position and the blocking device is located in the channel in a blocking position, movement of the first slider is blocked, preventing the sash arm from moving to the closed position.30. A friction hinge including a blocking device according to any of claims 22 to 29.31. A friction hinge for supporting a sash between a closed position and an open position, the hinge comprising a channel, a sash arm for supporting a sash, first and second sliders slidably mounted in the channel, one or more link arms coupled directly or indirectly to the sliders in use to provide a friction hinge movement of the sash arm relative to the channel, and restricting means for releasably securing the first slider to the channel, the restricting means being movable between an unreleased configuration, in which it prevents sliding movement of the first slider and a released configuration in which the first slider can move relative to the channel, wherein the second slider or an extension thereof is contactable with the restricting means to convert the restricting means to the released configuration.32. A friction hinge according to claim 31 wherein the hinge supports a sash between a closed position and a fully open position, the second slider or extension thereof being contactable with the restricting means when the sash is in the fully open position.33. A friction hinge according to claim 31 or 32 wherein the sash is movable between a closed position in which the sash arm is substantially parallel to the channel and a fully open position in which the sash arm is substantially perpendicular to the channel.34. A friction hinge according to any of claims 31 to 33, the restricting means having a sloped surface which slopes towards the second slider, the second slider or extension thereof being contactable with the sloped surface of the restricting means.35. A friction hinge according to any of claims 31 to 34, the second slider or an extension thereof having a sloped surface which slopes towards the first slider, the sloped surface of said second slider or extension thereof being contactable with the restricting means.36. A friction hinge according to any of claims 31 to 35, the restricting means having a sloped surface which slopes towards the second silder and the base of the channel and the second slider or extension thereof having a sloped surface which slopes towards the first slider and away from the base of the channel, the sloped surface of the first slider being contactable with the sloped surface of the second slider or extension thereof.37. A friction hinge according to any of claims 31 to 36 wherein biasing means is provided to bias the restricting means into its unreleased configuration.38. A friction hinge according to claim 37 wherein the biasing means comprises a spring, which in use urges the restricting means away from the channel.39. A friction hinge according to any of claims 31 to 36 wherein the channel includes a bottom, two side walls and a pair of inwardly facing flanges, the restricting means or portion thereof engaging with at least one cut-out region in the inwardly facing flanges when the restricting means is in the unreleased configuration.40. A friction hinge according to claim 39 wherein the restricting means and second slider or extension thereof are adapted such that contact of the second slider or extension thereof with the restricting means moves the restrictin means tpwards the bottom of the channel into the release configuration, whereby in the released configuration the restricting means or portion thereof does not engage with the at least one cut-out region of the inwardly facing flanges.41. A friction hinge according to any of claims 31 to 40 wherein the restricting means is attached to the first slider and moves along the channel therewith.42. A friction hinge according to any of claims 31 to 41 wherein the restricting means is formed integrally with the first slider.43. A friction hinge according to any of claims 31 to 32 wherein at least one link arm is pivotally coupled to said first slider and at least one link arm and a further at least one link arm is pivotally coupled to said second slider.44. A friction hinge for supporting a sash between a closed position and an open position, the hinge comprising a channel, a sash arm for supporting a sash, a first slider slidably mounted in the channel, one or more link arms coupled directly or indirectly to the first slider to provide a friction hinge movement of the sash arm relative to the channel, and restricting means for releasably securing the first slider to the channel, the restricting means being movable between an unreleased configuration, in which it prevents sliding movement of the first slider and a released configuration in which the first slider can move relative to the channel, the restricting means engaging magnetically with the channel when the restricting means is in the released configuration.45. A friction hinge according to claim 44, wherein the channel comprises a channel in which the first slider is slidably mounted.46. A friction hinge according to claim 45, wherein the restricting means includes a permanent magnet and the channel having a bottom, the bottom of the channel or a portion thereof being ferromagnetic, the permanent magnet of the restricting means magnetically engaging with a bottom of the channel, when the restricting means is in the released configuration.47. A friction hinge according to any of claims 44 to 46 wherein biasing means is provided to bias the restricting means into its unreleased configuration.48. A friction hinge according to claim 47 wherein the biasing means comprises a spring.49. A friction hinge according to any of claims 44 to 48 wherein the restricting means is engageable with a portion of the channel, preventing movement of the first slider.50. A friction hinge according to any of claims 44 to 49 wherein the channel includes a bottom, two side walls and a pair of inwardly facing flanges, the restricting means or portion thereof being engageable with at least one cut-out region in the inwardly facing flanges, preventing movement of the first slider.51, A friction hinge according to claim 50 wherein the restricting means is convertible from the unreleased configuration to the released configuration by movement of the restricting means in a direction towards the bottom of the channel, whereby the restricting means or portion thereof is disengageable from the at least one cut-out region of the inwardly facing flanges.52. A friction hinge according to claim 50 or 51 wherein the bottom of the channel includes an aperture, wherein when moving the hinge from the open position to the closed position, the restricting means is moveable over the aperture, whereby, the restricting means is released from magnetic engagement with the channel.53. A friction hinge according to any of claims 50 to 52 wherein the bottom of the channel is ferromagnetic and includes a non-ferromagnetic region, wherein when moving the hinge from the open position to the closed position, the restricting means is moveable over the non-ferromagnetic region, whereby, the restricting means is released from magnetic engagement with the channel.54, A friction hinge according to of claims 44 to 53 wherein the restricting means is attached to the first slider and moves along the channel therewith.55, A friction hinge according to any of claims 44 to 53 wherein the restricting means is formed integrally with the first slider.56. A friction hinge for supporting a sash between a closed position and an open position, the hinge comprising a charnel, a sash arm for supporting a sash, a first slider slidably mounted in the channel, one or more link arms coupled directly or indirectly to the first slider in use to provide a friction hinge movement of the sash arm relative to the channel, and blocking means for preventing first slider from moving the sash from the open position to the closed position, the channel having a bottom, two side walls and a pair of inwardly facing flanges and at least one cut-out region in the inwardly facing flanges, the blocking means being attached to or integral with the first slider in use and having at least one chamfered surface, such that the sash is movable from the closed position to an open position but is prevented from moving from the open position to the closed position by engagement of a portion of the blocking means with said at least one cut-out region in the inwardly facing flanges.57. A friction hinge according to claim 56, wherein the blocking means is convertible between an unreleased configuration in which said portion of the blocking means is in engagement with said at least one cut-out region in the inwardly facing flanges and a released configuration in which said portion of the blocking means is disengaged from said at least one cut-out region and the sash is movable from the open position to the closed position.58. A friction hinge according to claim 56 or 57 wherein biasing means is provided to bias the blocking means into its unreleased configuration.59. A friction hinge according to claim 58 wherein the biasing means is a spring.60. A friction hinge according to any of claims 56 to 59 wherein the channel has a proximal end and a distal end, the first slider moving from the distal end of the channel towards the proximal end as the sash is moved from the closed position to the open position, said at least one chamfered surface of the blocking means sloping down towards the bottom of the channel in the direction towards the proximal end of the channel.61. A friction hinge according to any of claims 56 to 60 wherein the blocking means is releasably attached to the first slider.62. A friction hinge according to any of claims 56 to 60 wherein the blocking means is formed integrally with the first slider.63. A friction hinge according to any of claims 56 to 62 wherein the sash is movable between a closed position in which the sash arm is substantially parallel to the channel and a fully open position in which the sash arm is substantially perpendicular to the channel.64. A friction hinge for supporting a sash between a closed position and an open position, the hinge comprising a fixed member and a sash arm for supporting a sash, the fixed member and sash arm being linked by an arrangement of link arms in use, the sash arm comprising means for enabling positioning of a sash edge relative to the proximal end of the sash arm, said means comprising a stop, the stop being a projecting extension of the sash arm against which an edge of the sash may abut, the stop being removably attachable to the sash arm.65. A friction hinge according to claim 64 wherein the stop is removably locatable at two or more different positions along the longitudinal axis of the sash arm.66. A friction hinge according to claim 64 or 65 wherein the sash arm has engagement means for removably engaging the stop, the sash arm having engagement means at two or more different positions along the longitudinal axis of the sash arm.67. A friction hinge according to any of claims 64 to 66 wherein the stop comprises at least one extending protrusion, the sash arm having at least one corresponding hole in which said at least one extending protrusion is removably ne L. recelvau e.68. A friction hinge according to any of claims 64 to 67 wherein the stop comprises first and second extending protrusions, the sash arm having a first set of corresponding first and second holes in which said first and second extending protrusions of the stop are respectively removably receivable.69. A friction hinge according to claim 68 wherein the sash arm further comprises a second set of corresponding first and second holes in which said first and second extending protrusions of the stop are removablyreceivable, the second set being located at a different position along the longitudinal axis of the sash arm from the first set.70. A friction hinge according to any of claims 64 to 69 wherein the stop is located near to the end of the sash arm.71. A stop for a friction hinge comprising a sash arm coupled to a fixed member by an arrangement of link arms, the stop enabling positive positioning of a sash edge relative to the proximal end of the sash arm, the stop, in use, being a projecting extension of the sash arm against which an edge of the sash may abut, the stop being removably attachable to the sash arm.72. A stop according to claim 71 wherein the stop comprises at least one extending protrusion, the sash arm having at least one corresponding hole in which said at least one extending protrusion is removably receivable.73. A friction hinge for supporting a sash between a closed position and an open position, the hinge comprising a fixed member and a sash arm for supporting a sash, the fixed member and sash arm being Pinked by an arrangement of link arms in use, the sash arm having means for enabling positioning of a sash edge relative to the proximal end of the sash arm, said means comprising at least one marker against which an edge of the sash may be aligned in use.74. A friction hinge according to claim 73 wherein the sash arm has two or more markers, each marker being at a different position along the longitudinal axis of the sash arm.75. A friction hinge according to any claim 73 or 74 wherein the or each at least one marker comprises at least one aperture in the sash arm, 76. A friction hinge according to claim 75 wherein the or each at least one marker comprises at least one aperture, the friction hinge further comprising a stop, in use, the stop being a projecting extension of the sash arm against which an edge of the sash may abut, the stop having at least one extending protrusion, said at least one extending protrusion being removably receivable in said at least one aperture.77. A friction hinge according to claim 76 wherein the stop has first and second extending protrusions, the or each at least one marker comprising first and second corresponding apertures in which the first and second extending protrusions are respectively removably receivable.78. A friction hinge according to any of claims 73 to 77, wherein said arrangement of link arms comprises at least a first link arm pivotally coupled, directly or indirectly, to the sash arm and the fixed member in use, the first link arm having at least one indication marker, the or each at least one indication marker being aligned with the or each at least one marker of the sash arm when the sash arm is substantially perpendicular to the fixed member.79. A friction hinge comprising a sash arm coupled to a fixed member by an arrangement of link arms in use, said arrangement of link arms comprising at least a first link arm pivotally coupled, directly or indirectly, to the sash arm and the fixed member in use, the first link arm having means for enabling positioning of a sash edge relative to the proximal end of the sash arm, said means comprising at least one indication marker against which an edge of the sash may be aligned when the sash arm is substantially perpendicular to the fixed member.80. A friction hinge according to claim 78 or 79 wherein the first link arm further comprises a label adjacent to the or each indication marker.81. A friction hinge for supporting a sash between a closed posifion and an open position, the hinge comprising a fixed member and a sash arm for supporting a sash, the fixed member and sash arm being linked by an arrangement of link arms, the hinge further comprising first and second contact means, the first contact means being located on the sash arm and the second contact means being located on the fixed member such that the first and second contact means contact one another when the hinge is in the closed position, whereby the sash arm is brought into correct alignment with the fixed member when the hinge is in the closed position.82. A friction hinge according to claim 81 wherein the first contact means has a circular shaped body.83. A friction hinge according to claim 82 wherein the first contact means is rotatably mounted to the sash arm.84. A friction hinge according to any of claims 81 to 83 wherein the second contact means has a recessed portion, the first contact means engaging a side of the recessed portion when the hinge is in the closed position.65. A friction hinge according to any of claims 81 to 84 wherein the first and second contact means are made from resilient material.86. A friction hinge according to any of claims 81 to 85 wherein the first contact means is located at or near the distal end of the sash arm and the second contact means is located at or near the distal end of the fixed member.87. A friction hinge for supporting a sash between a closed position and an open position, the hinge comprising a fixed member and a sash arm for supporting a sash, the fixed member and sash arm being linked by an arrangement of link arms in use, the arrangement of link arms comprising at least a first link arm, the hinge further comprising a riser, the riser comprising a ramped top surface, the riser being located on the at least first link arm or on the fixed member in use such that the sash arm is contactable with the ramped top surface of the riser when moving towards the closed position.88. A friction hinge according to claim 87 wherein said at least first link arm has top and bottom surfaces, the top surface facing the sash arm when the hinge is in the closed position, the first link arm having a depressed portion for receiving the riser such that the sash arm is contactable with the ramped portion of the riser when moving towards the closed position. 3D89. A friction hinge according to claim B? or 86 wherein the riser has an underside, opposing the ramped top surface, the underside having at least one protrusion extending therefrom, the first link arm comprising at least one aperture for receiving the at least one protrusion in use.90. A friction hinge according to any of claims 88 to 89 wherein the riser comprises a pair of side walls extending away from the underside of the riser, the first link arm being received between the side walls of the riser in use.91. A friction hinge according to any of claims 88 to 90 wherein the riser is made from a resilient niaterial.92. A friction hinge for supporting a sash between a closed position and an open position, the hinge comprising a channel, a sash arm for supporting a sash, a first slider slidably mounted in the channel, and at least one link arm pivotally coupled to the first slider at a first pivot point in use, the slider comprising a plastic body and having top and bottom opposing faces, the bottom face of the slider facing the channel in use, the slider further having at least one recess in its bottom face in which a metal plate is received in use, the slider body and metal plate having corresponding holes in which a pivot pin is receivable.93. A friction hinge according to claim 92 wherein the slider has first and second recesses in its bottom face in which first and second metal plates are received respectively, the metal plates each having a hole, the slider having first and second holes which align with the holes of the first and second metal plates respectively in use, in which first and second pivot pins are receivable respectively.94. A friction hinge according to any claim 92 or 93 wherein the or each pivot pin comprises a rivet for pivotally attaching a link arm member to the slider.95. A friction hinge according to any of claims 92 to 94 wherein the slider body is made of glass filled nylon.96. A friction hinge according to any of claims 92 to 95 wherein the or each metal plate is made of steel.97. A slider for a friction hinge which supports a sash between a closed position and an open position, the hinge comprising a channel and a sash arm for supporting a sash, the slider being slidably mountable in the channel, the slider comprising a plastic body and at least one metal plate, the plastic body having top and bottom opposing faces, the bottom face of the plastic body facing the channel in use, the plastic body having at least one recess in its bottom face in which the metal plate is received in use, the slider body and metal plate having corresponding holes in which a pivot pin is receivable to pivotally attach a link arm to the slider.98. A sash attachment member for a friction hinge, the friction hinge comprising a fixed member and a sash arm for supporting a sash between a closed position and an. open position, the sash attachment member extending substantially perpendicular to the sash arm in use, the sash attachment member being attachable to the sash in use.99. A sash attachment member according to claim 98, wherein the sash attachment member includes at least a first sash mounting aperture for receiving fixing means for fixing the sash attachment member to the sash in use.100. A sash attachment member according to claim 98 or 99, wherein the sash attachment member comprises an upstanding portion which projects substantially perpendicular to the sash arm in use and a mounting portion substantially perpendicular to the upstanding portion, the mounting portion being attachable to the sash arm.101. A sash attachment member according to claim 100, wherein the mounting portion has at least one sash arm mounting aperture for receiving fixing means for fixing the sash attachment member to the sash arm in use.102. A sash attachment member according to any of claims 100 to 101, wherein the mounting portion lies between the sash arm and a link arm in use.103. A sash attachment member according to claim 102, wherein the mounting portion comprises at least a first sash arm mounting aperture for receiving fixing means for fixing the sash attachment member to the sash arm in use, the sash arm mounting aperture aligning with an aperture in the sash arm and an aperture in a link arm that links the sash arm and fixed member of the hinge in use such that fixing means may be received through the sash arm mounting aperture and the apertures of the sash arm and link arm, fixing the sash attachment member to the sash arm in use and pivotally coupling the sash arm and link arm in use.104. A sash attachment member according to any of claims 100 to 103, wherein the upstanding portion has a leading edge and a trailing edge, the trailing edge facing in the direction of closure of the sash in use, the upstanding portion comprising a hook-shaped projection on its trailing edge.105. A friction hinge for supporting a sash arm between a closed position and an open position, the hinge comprising a fixed member and a sash arm for supporting a sash, the fixed member and sash arni being linked by at least one link arm in use, the friction hinge further comprising a sash attachment member according to any of claims 98 to 104.106. A friction hinge according to claim 105, the sash arm having a proximal end and a distal end, the proximal end of the sash arm having a projection and the fixed member having an end portion comprising a first upstanding member, the first upstanding member having an aperture in which the projection of the sash arm is received when the hinge is in the closed position.107. A friction hinge according to claim 106, the sash attachment member further comprising a first projection extending in a proximal direction in use, the projection of the sash attachment member being received in the aperture in the first upstanding member or being positioned adjacent to the first upstanding member when the hinge is in the closed position.108. A friction hinge according to claim 106 or 107, the sash attachment member further comprising a projection corresponding to the projection of the sash arm, the projections of the sash attachment member and sash arm being received in the aperture in the first upstanding member when the hinge is in the closed position.109. A link arm for a friction hinge, the friction hinge supporting a sash between a closed position and an open position and having a fixed member and a sash arm for supporting a sash, the link arm being pivotally coupled directly or indirectly to the fixed member and the sash arm in use, the link arm comprising a planar portion and an overhang portion, the overhang portion extending substantially perpendicular to the planar portion of the link arm.110. A link arm according to claim 109, wherein the planar portion and overhang portion are substantially elongate, the longitudinal axis of the planar portion and the overhang portion being substantially parallel.111. A link arm according to claim 109 or 110, wherein the planar portion comprises a leading edge and a trailing edge, the overhang portion extending from the leading edge of the planar portion.112, A link arni according to any of claims 109 to 111, wherein the overhang portion includes a resilient member which compresses against the sash when the sash is in the closed position.113. A link arm according to any of claims 109 to 112, wherein the fixed member of the friction hinge comprises a channel, the friction hinge further comprising a first slider slidably mounted in the channel, the link arm being pivotally coupled to the first slider.114. A friction hinge for supporting a sash between a closed position and an open position, the hinge comprising a fixed member, a sash arm for supporting a sash, the fixed member and sash arm being linked by a linkage in use, the linkage comprising at least one link arm in accordance with any of claims 109 to 113, the at east one link arm being pivotally coupled directly or indirectly to the fixed member and the sash arm in use.115. A friction hinge, a kits of parts, a blocking device, a stop for a friction hinge, a sash attachment member, or a link arm substantially as hereinbefore described with reference to any suitable combination of the accompanying drawings.Amendments to the claims have been filed as follows: Claims 1. A friction hinge for supporting a sash between a closed position and an open position, the hinge comprising a channel, a sash arm for supporting a sash, first and second sliders slidably mounted in the channel, one or more link arms coupled directly or indirectly to the sliders in use to provide a friction hinge movement of the sash arm relative to the channel, and restricting means for releasably securing the first slider to the channel, the restricting means being movable between an unreleased configuration, in which it prevents sliding movement of the first slider and a released configuration in which the first slider can move relative to the channel, wherein the second slider or an extension thereof is contactable with the restricting means to convert the restricting means to the released configuration.2. A friction hinge according to claim 11 wherein the hinge supports a sash between a closed position and a fully open position, the second slider or extension thereof being contactable with the restricting means when the sash is in the fully open position.3. A friction hinge according to claim 1 or 2 wherein the sash is movable between a closed position in which the sash arm is substantially parallel to the channel and a fully open position in which the sash arm is substantially perpendicular to the channel.4. A friction hinge according to any preceding claim, the restricting means having a sloped surface which slopes towards the second slider, the second slider or extension thereof being contactable with the sloped surface of the restricting means.
5. A friction hinge according to any preceding claim, the second slider or an extension thereof having a sloped surface which slopes towards the first slider, the sloped surface of said second slider or extension thereof being contactable with the restricting means.
6. A friction hinge according to any preceding claim, the restricting means having a sloped surface which slopes towards the second slider and the base of the channel and the second slider or extension thereof having a sloped surface which slopes towards the first slider and away from the base of the channel, the sloped surface of the first slider being contactable with the sloped surface of the second slider or extension thereof.
7. A friction hinge according to any preceding claim wherein biasing means is provided to bias the restricting means into its unreleased configuration.
8. A friction hinge according to claim 7 wherein the biasing means comprises a spring, which in use urges the restricting means away from the channel.
9. A friction hinge according to any preceding claim wherein the channel includes a bottom, two side walls and a pair of inwardly facing flanges, the restricting means or portion thereof engaging with at least one cut-out region in the inwardly facing flanges when the restricting means is in the unreleased configuration.
10. A friction hinge according to claim 9 wherein the restricting means and second slider or extension thereof are adapted such that contact of the second slider or extension thereof with the restricting means moves the restricting means towards the bottom of the channel into the release configuration, whereby in the released configuration the restricting means or portion thereof does not engage with the at least one cut-out region of the inwardly facing flanges.
11. A friction hinge according to any preceding claim wherein the restricting means is attached to the first slider and moves along the channel therewith.
12. A friction hinge according to any preceding claim wherein the restricting means is formed integrally with the first slider.
13. A friction hinge according to any preceding claim wherein at least one link arm is pivotally coupled to said first slider and at least one link arm and a further at least one link arm is pivotally coupled to said second slider.
14. A friction hinge substantially as hereinbefore described with reference to any suitable combination of the accompanying drawings.