GB2304148A

GB2304148A - Hinge Mechanism for an Openable Wing

Info

Publication number: GB2304148A
Application number: GB9616862A
Authority: GB
Inventors: Jason Paddock
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-08-11
Filing date: 1996-08-12
Publication date: 1997-03-12
Anticipated expiration: 2016-08-12
Also published as: GB9616862D0; GB2304148B

Abstract

A hinge mechanism comprises a channel element 102 fixed to the frame, a supporting rail 122 to be secured to the wing, and scissors links 106, 108 interconnecting the channel and rail. One link 108 is connected to the rail by a fixed pivot 120 and to the channel by means of a locating block 116 which comprises a serrated locking element which can be clamped into engagement with serrations on the channel by a clamping screw 140, which permits the position of the fixed pivot 112 to be adjusted along the channel. The other link 106 is pivotally connected to the channel by a sliding block 114, and to the rail by a pivot 118 which is slidably engaged in a slot 124 in the rail. The links are interconnected by a pivot 125 which may comprise an eccentric element 142 which can be adjusted to vary biassing of the wing into or away from the closed position. The pivot 112 may be offset from the axis of the channel 102.

Description

HINGE MECHANISMS FOR OPENABLE WINDOWS AND OTHER SUCH MOVABLE PANELS This invention concerns improvements in and relating to hinge mechanisms for windows and other such movable panels.

It is common practice for windows to be mounted on linkage-type hinge mechanisms which provide for the window sash and frame to separate following initial opening. Such hinges can provide greater structural support for large windows, and also provide better adjustability as to a fully opened position.

However, the geometry of pivots and stays involved in many designs of such hinges make a full 900 opening of the window relative to the frame impossible, or at best impracticable, due to geometric and/or material constraints of the hinges concerned.

Systems which do provide 90" opening usually do so at the expense of other desirable features, such as security against prising attack.

Known mechanisms also tend to reduce the size of aperture available for escape, through poor positioning of the open window.

It is an object of the present invention to provide an improved design of hinge mechanism which ensures that a large escape aperture can be provided when the mechanism is fitted.

In addition the invention aims to produce a more tolerant design with regard to manufacturing, installation and adjustment during the article's life.

The invention provides, in one of its aspects, a hinge mechanism for a window or other movable panel comprising a frame mounting element for securement of the mechanism to a surrounding frame and a panel mounting element for securement to the panel, the frame mounting element being connected to the panel mounting element by means of scissors links comprising crossed positioning elements which are pivotally connected at their ends to the frame and panel mounting elements respectively and pivotally connected to one another at a position between their ends, locating means pivotally connecting one of the positioning elements to the frame mounting element permitting movement for adjustment relative to the frame mounting element and enabling securement in adjusted position.

According to a second aspect of the invention we provide a hinge mechanism comprising a frame mounting element and an aperture closure mounting element the frame mounting element being attached to the aperture closure mounting element by a plurality of positioning elements, at least two of the positioning elements being pivotally mounted with regard to both the frame mounting element and the aperture closure mounting element, wherein said first and second positioning elements cross-over one another.

According to a third aspect of the invention we provide a hinge mechanism comprising a frame mounting element and an aperture closure mounting element the frame mounting element being attached to the aperture closure mounting element by a plurality of positioning elements, at least two of the positioning elements being pivotally mounted with regard to both the frame mounting element and the aperture closure mounting element, wherein the separation between the pivotal mountings of said two positioning elements on the frame mounting means is variable and wherein the separation between the pivotal mounting of said two positioning elements on the aperture closure mounting element is variable during movement of the aperture closure mounting element relative to the frame mounting element.

In these ways full escape openings with 900 window opening in manufacturing tolerant designs can be achieved.

Preferably the locating means comprises a locking element and clamping means whereby the locking element can be clamped against the frame mounting element to prevent movement of the locating means along the mounting element. The locking element may present formations (e.g.

transverse serrations) which are interengageable with formations presented by the frame mounting element to prevent relative movement between the elements. The clamping means may comprise a clamping screw which is arranged (when tightened up) to hold the locking element in engagement with the frame mounting element.

According to a fourth aspect of the invention there is provided a hinge mechanism for a window or other movable panel comprising a frame mounting element for securement of the mechanism to a surrounding frame and a panel mounting element for securement to the panel, the frame mounting element being connected to the panel mounting element by means of scissors links comprising crossed positioning elements which are pivotally connected at their ends to the frame and panel mounting elements respectively and pivotally connected to one another at a position between their ends, means pivotally connecting the crossed positioning elements being arranged to bias the panel into or away from a fully closed position.

The biasing means is preferably adjustable to vary its effect. In a preferred construction, the biasing means comprises an eccentric compression member acting between the positioning elements.

According to a fifth aspect of the invention there is provided a hinge mechanism for a window or other movable panel comprising a frame mounting element for securement of the mechanism to a surrounding frame and a panel mounting element for securement to the panel, the frame mounting element being connected to the panel mounting element by means of a plurality of links which are pivotally connected at their ends to the frame and panel mounting elements, means pivotally connecting one of the positioning elements to the frame mounting element permitting movement along the frame mounting element and comprising adjustment means whereby frictional resistance to movement of the positioning element can be varied.

Alternatively or in addition to the features presented above in one or more of the aspects, there may be included one or more of the following features.

Preferably at least one of the positioning elements to aperture closure mounting means pivotal mountings is slidably provided. In this way variations in the pivot to pivot distance can be provided giving the system a self correcting geometry.

Most preferably the sliding pivot is the distal one relative to the frame mounting means in the open position. This enables the full 90" opening to be effected with relatively short limits.

Preferably the sliding pivot is provided in a slot, most preferably longitudinally aligned, in the aperture closure mounting means.

The aperture closure mounting means may be provided with a number of apertures to accommodate fastenings for attachment to the aperture closure. Most preferably a perpendicular element, relative to the plane of the hinge, is provided. This offers enhanced security.

Preferably the variation in separation between the positioning element mountings on the frame mounting means is effected by one or more, most preferably one, of the mountings being slidably engaged.

Preferably the pivot slides along the frame mounting means.

Preferably the sliding pivot is on the positioning element slidably engaged with the aperture closure mounting means. Most preferably the other pivot with the frame mounting means is fixed in normal use.

Preferably the frame mounting means comprises a profiled channel.

Preferably the sliding pivot is mounted in the channel, most preferably on a mounting block, which ideally is of corresponding profile to the channel.

Preferably the channel is provided with one or more apertures to facilitate its fixing to the frame.

Preferably the normally fixed pivotal mounting between positioning element and frame mounting means is adjustable, if required, most preferably also by means of a sliding engagement. Preferably the pivot is provided on a mounting block, most preferably adapted to engage a profile channel form frame mounting means.

Preferably the adjustment is effected by releasing a fastener to allow movement of the pivot and tightening the fastener to restrain the pivot. Preferably a thread member is provided to this end. Most preferably the fastener has a channel engaging surface, most preferably for the channel base. Preferably the engaging surface and or channel are provided with notches, ribs or other restraint aiding means. This gives a firm fixing.

Preferably the angle a defined by the cross over of the positioning elements in the triangle defined by the elements and the frame mounting means varies between 160-180 when closed to less than 45" when fully opened. Most preferably less than 350 when open.

Preferably the aperture closure mounting means is closer to the near perpendicular edge of the aperture when fully opened than either of the pivots.

Preferably at least two positioning elements are pivotally mounted relative to each other.

In a particularly preferred embodiment the positioning element pivotal mounting is provided as a cam. In this way encouragement for the positioning elements to pivot relative to one another during the last stages before full closure, for example, can be provided giving positive closure and/or opening.

Preferably the cam is adjustable to vary the degree of encouragement and/or its geometrical location.

According to a fourth aspect of the invention we provide a frame and/or aperture closure fitted with a hinge mechanism according to any one of the preceding aspects.

Most preferably the aperture closure is a window.

An embodiment of the invention will now be described by way of example only and with reference to the accompanying figures in which: Figure 1 illustrates a prior art Anderberg design of window hinge in the open position; Figure 2 illustrates a detail of the hinge of Figure 1 in the nearly closed position; Figure 3 illustrates the prior art hinge of Egress type in the open position; Figure 4 illustrates a detail of the hinge of Figure 3 in the nearly closed position; Figure 5 illustrates a prior art hinge of the 4-bar type in the open position; Figure 6 illustrates a side detail of the hinge of Figure 5 in the closed position; Figure 7 illustrates the hinge according to a first embodiment of the present invention in the fully open position; Figure 8 illustrates the hinge of Figure 7 part open; Figure 9 illustrates the hinge of Figure 7 in a closed position; and Figure 10 illustrates a side view of the hinge of Figures 7,8 and 9 along axis X-X in Figure 9; Figure 11 is a plan view of a second embodiment of hinge mechanism shown in a partly open condition, a scissor stays pivot being shown in an enlarged detail of the drawing; Figures 12A and 12B are side and underneath plan views of an eccentric compression rivet of the pivot; Figure 13 is a plan view of the second hinge shown in a fully closed condition; Figure 14 is an enlarged view in section on line XIV-XIV of Figure 13; Figures 15A and 15B are a top plan view and a central longitudinal sectional view of a moulded locking element; Figure 16 is a plan view of a frame channel of the mechanism; and Figure 17 is an enlarged view in section on line XVII-XVII of Figure 13.

The prior art hinge illustrated in Figures 1 and 2 consists of a profiled channel 1 provided with a stay head 2, fixed pivot 3 and sliding element 4 contained within the channel. This assembly gives the frame mounting means.

The sliding element 4 carries pivots 5,6 for elements 7 and 8 which are respectively attached by pivotal mountings 9,10 to further stay elements 11 and 12 respectively. The element 11 being attached to pivot 3 and by a further pivot 14 to stay 12. The stay 12 is provided with apertures 16 to accommodate fixing for attaching the window to this element. The stay 12 and stay 8 bear the load of the window in this system, The stay 12 forming the aperture closing mounting means.

This system faces a number of problems. Firstly, the design is critically dependent upon the distance between the fixed pivot 3 and the stay head 2. If the distance between these two points is too short then the stay 12 and its end portion 18 slop around unduly in the head of the stay 2 causing poor weather-tightness and a lack of security.

Oii the other hand, if the distance between point 3 and 2 is too long, then the stay element 12 applies a longitudinal force to the head of the stay 2 trying to force it off.

In addition the geometry of the system is such that during the opening movement play in the various elements can lead to the geometry locking out before the fully opened position is reached. Whilst it is usually possible to overcome this problem by using the window to provide leverage this causes excessive wear on the rivet points leading to further problems and a limited life for the system.

Additionally as there is only one load bearing arm 8 in this design it is imperative that this arm's length be kept as short as possible as otherwise the thickness of material required to support a large window is intolerably thick. As a consequence, as this element must be relatively short, a 900 opening for the window relative to its frame is nonachievable. Furthermore, even where a high angle of opening is achieved, the window advances inwardly (direction A) relative to the aperture leaving two apertures, one on either side of its projecting form.

As a consequence the overall aperture size available for escape, for instance during a fire, is restricted by this design.

The Anderberg design also faces a number of problems when installing as well as during adjusting the system at a later date during its lifetime to accommodate wear within the various components. Adjustment of the channel up and down the frame is provided by means of fixing holes 20 and 22 provided in the channel 1. Whilst these provide a reasonable means for adjusting the system where a security head is not employed during initial installation, they offer poor adjustment later when needed due to wear in the system. The problem in this regard is that the necessary adjustment would not be a full hole's distance away and that as a consequence any new hole would overlap giving rise to play.

Adjustment is even more difficult on security type installations of this window as the head of the stay 2 has a perpendicular fixing screw which stops adjustment on the channel 1 relative to the frame.

Adjustment is only possible in security options by adjusting the position of the window relative to the stay element 12 and fixing it on that.

However, these fixings are not accessible from the inside of the window making on-site adjustment, for instance in tower blocks, very difficult as external access is required.

As can be seen the Anderberg design faces a considerable number of problems.

Figures 3 and 4 illustrate an alternative type of prior art hinge, the so-called Egress stay. As illustrated in the drawings, the design has certain common features to the Anderberg design from which it is derived. Thus the system consists of a profiled channel 30, provided with a stay head 32 and a fixed pivot carrying block 34 which is profiled to cooperate with the channel 30 and a sliding block 36 which also co-operates with the channel 30.

The block 34 provides pivotal mountings 38,40 for elements 39 and 41, with the sliding block 36 providing a pivotal mounting 42 for an element 43 which is also pivotally connected to element 39 by pivot 44.

Both the element 43 and element 41 are pivotally connected at separate locations 46 and 48 respectively to the window supporting element 50.

As with the Anderberg design the end portion 52 of the window supporting element 50 is designed to co-operate with the head 32.

Whilst the Egress design does allow escape access through the window given a near 900 opening and with the window being positioned close to the frame, it still suffers a number of disadvantages.

Firstly because of the relatively shallow angle at which the end portion 52 of the stay 50 enters the security head (from the Figure 4 position to fully closed little movement in direction X occurs) the design offers practically no resistance to prising attack (direction Y) by intruders. The shallow level of penetration, in contrast to the Anderberg design, offers little resistance. This shallow angle of engagement also makes weather sealing very difficult as the shallow angle provides little compensation for any inaccuracy in the tolerance between the hinge and the stay head. As a consequence manufacturing tolerances with regard to the hinge assembly have to be very high indeed if any level of weather sealing is to be obtained.

As with the Anderberg design the entire weight of the window is still taken by a single load-bearing arm 41. Whilst the configuration provided by the Egress stay allows for a thicker material to be employed within this stay, this unfortunately tends to reduce the weather-tightness of the system and again restricts the length of stay which can be employed for this element before the length causes the hinge to bend undesirably.

Thus the Egress offers fire-safety and the Anderberg offers security but neither provide both functions.

The third prior art design illustrated in Figures 5 and 6 is the socalled 4-Bar design. This system consists of a base element 70 which is provided with a base portion 71 designed to co-operate with the so-called standard or slim-line width of a window frame for which the unit is designed to fit. The base element 70 carries two pivot points 72 and 74 about which stay elements 76 and 78 pivot. Both of these elements 78, 76 are connected to the window supporting stay 80 by pivots 81, 82 respectively. As with the previous units the end portion 83 of the stay 80 co-operates with a head feature 84 provided on the plate member 70.

Once again the nature of this design makes it impossible to achieve 900 opening and also brings the window across the aperture during opening so reducing the chance of escape.

In addition this design solely relies upon the friction of the various pivots 72,74,81,82 to hold the hinge open. As a consequence it is difficult to maintain the desired level of friction throughout the life of the article. The tendency is for the hinges to be undesirably tight at the start of their life and undesirably loose at later dates. This system lacks any way in which regular adjustment can be made.

In addition the load bearing arm 78 does not lock into the head of the unit (gap 85 in Figure 6) so failing to provide any security against prising action applied to that element.

Again, as with the preceding design, the manufacturing tolerances for the rivet point are absolutely essential to ensure that the hinge closes to the correct position to achieve any degree of weather-tightness.

A further flaw with the 4-Bar design is that the frame plate 70 required does not correspond to the standard width employed in window frames because the rivets have to be off-set, portion 86, to allow the geometry of this design to close properly without the additional heads on the stay. Because of this there are great difficulties when fitting the stay to most window profiles and a need to modify the frame, which is clearly undesirable, arises.

As can be seen, whilst there are a number of designs in existence, these fail for a variety of reasons to achieve the degree of versatility provided by the present invention.

As illustrated in Figures 7,8,9 and 10, showing an embodiment of the invention, the hinge system 100 comprises a profiled channel 102 provided with a number of apertures 104 for fixing purposes, so forming a frame mounting element to be secured to a window frame.

Positioning elements 106,108 in the form of scissor stays are mounted at pivots 110 and 112, respectively, to locating means comprising mounting block assemblies 114,116, respectively, which are accommodated within the channel 102. The block 116 (which will be positioned furthest from a frame corner) is fixedly positioned relatively to the channel 102 in normal use. The other block 114 closest to the window frame is slidably mounted in the channel, moving towards the fixed block 116 during opening and moving away from it (towards the frame corner) during closing of the hinge assembly.

The scissor stays 106,108 are mounted (at their opposite ends from the frame mounting element) by means of pivots 118,120 to a window supporting rail 122 forming a window mounting element. The pivot 120 is accommodated within a circular aperture in the rail 122 whilst the pivot 118 is slidably mounted within a longitudinal slot 124 in the rail 122. A pivot 125 interconnects the scissor stays 106,108 at a position between their ends.

The sliding pivot 110 on the frame mounting channel 102 is provided in screw form allowing the tightness of the sliding movement to be adjusted maintaining the desired hinge system stiffness over time.

By locating one of the stay pivots 118 in a slot 124 the geometry of the system becomes self-correcting as the pivot positions are no longer absolutely fixed relative to each other. This not only accommodates wear with use but also means that the pivot to pivot distance during manufacture is no longer so critical, reducing production costs.

The window rail 122 is provided with a number of apertures 126 to allow fixing of this element to the sash of the window to be supported.

During opening of the window the rail 122 moves outward from the closed position (Figure 9) through the part-open position shown in Figure 8, to the fully-open position shown in Figure 7. During opening the scissor stays 106, 108 come together, reducing the angle a (Figures 7 and 8) between them. The maximum extent of opening is determined by the sliding block 114 abutting the end of the fixed block 116 and/or the pivot 118 reaching the inner end of the longitudinal slot 124 in the window rail 122. As can be seen from Figure 7, in this position not only is a substantially 900 opening obtained but also the window opens to a position in close proximity to the frame corner, giving the maximum escape aperture possible.

Closure of the window simply reverses the process with the angle a increasing as the window rail 122 approaches the closed configuration.

The geometry of the design is such that the rail 122 is pulled fully back into position without any need for an end cap to guide it. Precise closing is thus effected.

By providing the scissor stays' pivot 125 in the form of a cam the degree of force promoting the closure during its final stages can be varied. An eccentric cam can thus actively encourage movement of the stays 106,108 through that stage. Adjustment of the cam can be achieved by a screw head engagement.

The use of the scissor stays 106,108 also represents an advance in terms of the window weight which can be deployed as both elements act as load bearers at all positions. Splitting the weight in this way enables large windows to be fitted with one size of hinge system and yet still achieve 90" opening.

The window rail 122 may optionally be provided with a perpendicularly arranged extension 128 (seen in Figure 10) also to be attached to the window sash and so improving the security of the attachment.

The design also presents a number of advantageous features during installation for the following reasons. As seen in Figure 10, the pivot 112 on the fixed block 116 is part of a screw assembly in which a lower portion 130 engages with a base 132 of the channel 102. The base is provided with a serrated portion 134 which co-operates with a serrated undersurface of the element 130. Thus adjustment of the position of the fixed block 116 can be effected without needing to move the channel 102 or the rail 122, relative to the window frame and window sash respectively.

During installation, the window rail 122 can be mounted on the window sash in the desired position, with the optional perpendicular element 128 secured around the corner of the window, and the frame channel 102 can be positioned up to the corner of the window frame as desired. The necessary adjustment of the window and frame relative to one another can then be effected by manoeuvring the block 116 into the desired position and fixing it there by means of the serrated screw engagement discussed above. Furthermore a similar type of adjustment can be effected during the life of the article to take up wear, if necessary.

As a further consequence of this adjustability, one size of hinge can be utilised for a large range of windows. Prior art systems require different size units for different operations, thus increasing costs.

Additionally if the hinge is subjected to attack, by prising for instance, the attack serves to push the unit in. The consequential transfer of force to the releasable fastening, a handle for instance, on the other part of the frame dissipates the attack.

A second embodiment of hinge mechanism according to the invention is illustrated by Figures 11 - 16. Components corresponding to those of the first embodiment have been given the same reference numerals in view of the similarity of construction and operation of the two hinges.

It is to be noticed that in the second hinge (see Figures 11 and 13) the pivot 112, by which one of the scissor stays 108 is secured to the fixed block 116, is offset from the frame channel 102 rather than on its centre-line. This construction makes it easier to accommodate the other stay 106 in the fully closed condition, and reduces the likelihood of one stay coming to bear upon the other. A separate locking screw 140 is provided, as further described hereinafter, for the purposes of securing the block 116 in adjusted position.

With regard to Figures 11 and 12, the scissor stays pivot 125 comprises biasing means comprising an eccentric compression rivet 142 which is arranged by an over-centre camming action to urge the mechanism finally into its closed condition. A hexagonal socket 144 enables the action of the rivet to be varied, by slight rotation of the rivet relative to the stays 106,108; a range of possible movement of the rivet is indicated by broken lines in the enlarged detail of Figure 11. As seen in Figure 12, the rivet comprises a disc-like head portion 146 which overlies one of the stays 108, a cylindrical locating peg 148 which engages in a circular aperture in the other of the stays 106, and a short cylindrical camming portion 150 which is arranged eccentrically between the head portion and the peg and engages in a circular aperture in the one of the stays 108.The locating peg 148 is peened over against an underside of the other stay 106 to secure the rivet in the stays.

The arrangement of the adjustable stay-mounting block 116 is illustrated in Figure 11 and (on a larger scale) Figure 14. The block comprises a bracket 152 which provides for the off-setting of the stay pivot 112 from the frame channel 102. A body plate 154 of the block lies over the channel, being slidably interengaged with the channel by means of laterally-extending tabs 153 to prevent its being lifted off the channel.

The body plate is interengaged with a moulded locking element 156 (see also Figures 15A andlSB) by means of depressions 158 in the plate which locate in corresponding apertures 160 in the locking element; this interengagement prevents relative movement between the plate and the locking element in the direction longitudinally of the channel. The locking element is positioned between the plate and the channel, as can be seen in Figure 14. The locking element comprises a portion forming a gripping block 162 of which an undersurface 164 is transversely serrated in order to interengage with similar serrations 166 (Figure 16) formed on an opposing bottom surface 168 of the channel.The locking screw 140 comprises a head 141 engaging an undersurface of the channel, and comprises a screw threaded stem which passes through a slot 170 in the channel 102, a threaded aperture 172 in the gripping block 162 of the locking element 156, and enters an aperture 174 in the body plate 154.

When tightened, the screw serves to pull down and clamp the locking element to the channel. To adjust the position of the block 116, the screw 140 is slackened off, the assembly moved, and the screw retightened in the adjusted position of the block. Once in final position, a screw can be driven through an eye 176 of the locking element to secure it permanently to the channel.

The construction of the sliding block 114 is shown in more detail in Figure 17. An end portion of the stay 106 which is connected to the block is located in a recess in a moulded slide bearing 178 which lies across an upper surface of the channel 102. An enlarged head 180 of a friction bush 182 is located in the channel, seated in a recess in a friction pad 184 which lies over it (also retained in the channel). The bush extends upwardly from the channel, a hexagonal upper portion 186 being located in a corresponding hexagonal aperture in the slide bearing 178, so that the bush and the slide bearing (and the stay 106) are interlocked to rotate together. A friction adjustment screw 188 is introduced downwardly through an aperture in the stay 106 to engage in a tapped bore of the friction bush 182, an enlarged head portion of the screw overlying an upper surface of the stay. By driving the screw into the bush, the head 180 of the friction bush is urged more tightly against the friction pad 184 within the channel (engaging undersurfaces of overlying inturned lips 190 of the channel) whereby to offer greater resistance to rotation of the stay 106 relative to the channel. The frictional adjustment for the sliding block 114 is, therefore, arranged at the pivot point itself rather than elsewhere.

Claims

1. A hinge mechanism for a window or other movable panel comprising a frame mounting element for securement of the mechanism to a surrounding frame and a panel mounting element for securement to the window panel, the frame mounting element being connected to the panel mounting element by means of scissors links comprising crossed positioning elements which are pivotally connected at their ends to the frame and panel mounting elements respectively and pivotally connected to one another at a position between their ends, locating means pivotally connecting one of the positioning elements to the frame mounting element permitting movement for adjustment relative to the frame mounting element and enabling securement in adjusted position.

2. A hinge mechanism according to claim 1 in which the locating means comprises a locking element and clamping means whereby the locking element can be clamped against the frame mounting element to prevent movement of the locating means along the mounting element.

3. A hinge mechanism according to claim 2 in which the locking element presents formations which are interengageable with formations presented by the frame mounting element to prevent relative movement between the elements.

4. A hinge mechanism according to either of claims 2 and 3 in which the clamping means comprises a clamping screw arranged to hold the locking element in engagement with the frame mounting element.

5. A hinge mechanism according to any one of claims 1 to 4 in which means pivotally connecting the crossed positioning elements is arranged to bias the window into or away from a fully closed position.

6. A hinge mechanism according to claim 5 in which the biasing means is adjustable to vary its effect.

7. A hinge mechanism according to claim 6 in which the biasing means comprises an eccentric compression member.

8. A hinge mechanism substantially as hereinbefore described with reference to Figures 1 to 10 or to Figures 11 to 17 of the accompanying drawings.

9. A hinge mechanism for a window or other movable panel comprising a frame mounting element for securement of the mechanism to a surrounding frame and a panel mounting element for securement to the panel, the frame mounting element being connected to the panel mounting element by means of scissors links comprising crossed positioning elements which are pivotally connected at their ends to the frame and panel mounting elements respectively and pivotally connected to one another at a position between their ends, means pivotally connecting the crossed positioning elements being arranged to bias the panel into or away from a fully closed position.

10. A hinge mechanism for a window or other movable panel comprising a frame mounting element for securement of the mechanism to a surrounding frame and a panel mounting element for securement to the panel, the frame mounting element being connected to the panel mounting element by means of a plurality of links which are pivotally connected at their ends to the frame and panel mounting elements, means pivotally connecting one of the positioning elements to the frame mounting element permitting movement along the frame mounting element and comprising adjustment means whereby frictional resistance to movement of the positioning element can be varied.