The present invention relates^o an adjustable roller hinge for a folding door, window or similar closure. In particular, the present invention is directed to an adjustable roller hinge having a lockable height-adjusting nut.

Background Art.

A roller hinge is used to support a hinged panel or a pair of hinged panels on a lower, or from an upper, horizontal track while permitting the panels to pivot about a vertical hinge axis which can move along the track. Typically, the panels are panels of a folding door, window or similar closure. If the roller hinge is used to support the end panel of a series of panels, it normally has one hinge leaf fixed to the panel. If the roller hinge is an intermediate roller used to support a pair of adjacent panels, it has a pair of hinge leaves, each fixed to a respective one of the pair of adjacent panels. Throughout this specification, where the context permits, the term "panel" is intended to refer to a leaf or generally planar closure component of a folding door, window, shutter, screen or like closure. The invention will be described with particular reference to its application to panels of a folding door, but the scope of the invention is not limited thereto . Typically, each roller hinge (except the roller hinge nearest the jamb) extends from a respective wheeled carriage which rides along the track. A combination of each roller hinge and its carriage forms a carrier hinge assembly.

A roller hinge typically comprises an upright roller bolt which serves as a hinge pin for a hinge leaf or leaves pivotally mounted thereon. The. bolt comprises a threaded portion to receive a nut thereon. The hinge leaves, which are axially slideable along the roller bolt, rest upon the nut and are supported thereon. The position of the nut on the roller bolt therefore determines the position of the hinge leaves relative to both the roller bolt and the track from which the roller bolt extends. Since the hinge leaves are fixed to the panels in use, the height of the panels can be adjusted by rotating the nut to vary its position along the threaded portion of the roller bolt Height adjustment of the panels is usually required from time to time to correct out-of- square movements of the panels and to prevent the door panels from sticking, or otherwise to facilitate smooth movement of the door panels. It is important to ensure that once the roller hinge has been properly adjusted, it does not lose its adjustment, i.e. that there is no undue rotation of the height-adjusting nut.

It has been found that with conventional roller hinges, repeated opening and closing of the panels can result in rotation of the nut, and hence loss of adjustment. In the past, a second (locking) nut has been used on the roller bolt to lock the height- adjusting nut in position. However, such locking nut arrangements are not always effective. Two spanners are usually required to adjust the height of the panels, and due to the positioning of the nuts in close proximity to the panels, damage may be caused to the panels through spanner slippage. In addition, locking nuts are prone to coming undone - either through poor initial tightening or through jarring or other force applied to the pair of locking nuts. Once the initial friction locking the nuts together is broken or reduced, the bolt and/or nuts are then free to rotate with no further restriction.

Australian patent no. 2004202218 discloses an adjustable hanger hinge in which height adjustment is achieved by providing a nut having a socket at one end and adapted to receive a nut adjusting tool.

Although the adjustable hanger hinge of Australian patent no. 2004202218 has been found to be satisfactory for most commercial and residential applications, it may not be the optimum design for ease of use. For instance, this design is not suited to a system where the carrier wheels are underneath the doors and the weight of the doors rests on top of the carrier assembly.

Thus, there would be an advantage if it were possible to provide an adjustable roller hinge that prevented unwanted loss of height adjustment during repeated use and also allowed for fast and simple adjustment when required. Summary of the Invention.

It is an object of the present invention to provide a roller hinge which may overcome at least some of the abovementioned disadvantages, or provide a useful or commercial choice. In one aspect, the invention resides broadly in a roller hinge for a folding door, window or similar closure having one or more panels, the roller hinge comprising a roller bolt having a threaded portion at one end thereof, a nut member adapted to be threaded onto the threaded portion of the roller bolt and locking means positioned between the roller bolt and the nut member and adapted to releasably lock the nut member against rotation relative to the roller bolt.

At least one hinge leaf may be pivotally mounted on the roller bolt, which may serve as a hinge pin. The or each hinge leaf may be mounted to the roller bolt using any suitable technique. Preferably, however, the or each hinge leaf has a knuckle portion with a bore therein. The bore may be adapted to receive at least a portion of the roller bolt therein. Preferably, the bore extends along the entire height of the knuckle portion, such that the knuckle portion forms a substantially tubular sleeve dimensioned to allow the roller bolt to pass at least partially through the bore. In use, the hinge leaf may be fixed to a respective panel. The operative position of the hinge leaf is dependent on the extent to which the nut member is threaded onto the roller bolt. In a preferred embodiment, the hinge leaf may be directly or indirectly supported by the nut member. For instance, the hinge leaf may abut the nut member, or, alternatively, spacing means of any suitable type may be located between the hinge leaf and the nut member. In embodiments of the invention in which a plurality of hinge leaves are present on the roller hinge, the hinge leaves may all be of the same size and configuration, or may be of differing sizes and configurations as required.

Preferably, as the nut member is threaded up and down the roller bolt (by rotating the nut member relative to the roller bolt), the position of the hinge leaf, and therefore the vertical position of the panel to which the hinge lead is fixed, varies up and down. Thus, the vertical position of the panel may be adjusted by rotating the nut member. In some embodiments of the invention (particularly where the roller hinge is adapted for attachment to an adjacent pair of panels), the roller hinge may be provided with a plurality of hinge leaves. In these embodiments of the invention, the plurality of hinge leaves may be positioned on the roller bolt such that adjacent hinge leaves are spaced vertically from one another. Adjacent hinge leaves may be in abutment with one another or, in a preferred embodiment of the invention, spacing means (such as one or more washers or the like) may be located between adjacent hinge leaves. In a preferred embodiment of the invention, the roller hinge is associated with a carriage. The carriage is preferably a wheeled carriage adapted to ride along a track. In a most preferred embodiment of the invention, the carriage is adapted to ride along a lower track, such as a sill track (for windows), floor track (for doors) or the like. The roller hinge may be formed integrally with the carriage or may be formed separately therefrom and adapted for fixed or removable attachment thereto using any suitable technique.

In a preferred embodiment of the invention, the threaded portion of the roller bolt may be provided at a lower end thereof. Thus, in embodiments in which the roller hinge is associated with a carriage adapted to ride along a lower track, the threaded portion of the roller bolt may be located adjacent the carriage. In this embodiment, when the nut member is threaded onto the threaded portion of the roller bolt, the lower limit of downward threading of the nut member on the threaded portion may be defined by the point at which the nut member abuts the carriage. The carriage may be of any suitable construction, and a skilled addressee would understand that the exact construction of the carriage is not critical to the present invention, although it is envisaged that the carriage may include at least one wheel to allow the carriage to ride along the track. The roller bolt may be of any suitable size, shape or configuration. Preferably, however, the roller bolt may include an elongate member. One or more hinge leaves may be associated with the roller bolt, for instance, as previously stated, the one or more hinge leaves may each be provided with a body having a bore for the roller bolt to pass through, although it will be appreciated that any suitable arrangement for bringing the roller bolt and the one or more hinge leaves into association with one another wherein the hinge leaves are movable relative to the roller bolt upon rotation of the nut member could be used.

The length of the roller bolt may be determined by the number of hinge leaves to be associated therewith. For instance, a roller bolt with which a single hinge leaf is to be associated may be shorter than one with which a plurality of hinge leaves are to be associated. Alternatively, all roller bolts may be fabricated to substantially the same specifications in order to simplify ease of use and installation.

The roller bolt may be suitably provided with limit means to prevent the one or more hinge leaves from moving relative to the roller bolt beyond a predetermined limit. For instance, the limit means may be provided to prevent the one or more hinge leaves from coming free from the roller bolt, or, alternatively, the limit means may be provided to ensure that the panels are allowed only a particular range of height adjustment.

Any suitable limit means may be provided. For instance, the roller bolt may be provided with an enlarged portion thereon to restrict the movement of the one or more hinge leaves beyond the enlarged portion. Such restriction may provide the benefit of preventing the nut member from being adjusted so far that it disengages from the threaded portion of the roller bolt, or from reaching a position where only one or two turns of the thread remain engaged, as this may result in inadvertent damage to the thread due to the weight of the doors. The enlarged portion may be provided at any suitable location on the roller bolt, and may be formed integrally with the roller bolt, or formed separately to the roller bolt and adapted for fixed or removable connection thereto. In a preferred embodiment of the invention, the limit means may comprise a cap having an enlarged portion and adapted for engagement with an upper end of the roller bolt (i.e. the end of the roller bolt furthest from the threaded portion). The cap may be provided with an engagement portion depending from the enlarged portion that is adapted for engagement with the upper end of the roller bolt. For instance, the engagement portion may be adapted to slide over the upper end of the roller bolt, or, alternatively, the engagement portion may be adapted to be retained within a bore provided in the upper end of the roller bolt, or the like.

In preferred embodiments of the invention, the roller bolt may be provided with at least one rebate portion thereon. The at least one rebate portion is preferably provided at least at or adjacent the lower end of the roller bolt, although it is envisaged that the at least one rebate may extend along any suitable length of the roller bolt. Preferably, the at least one rebate extends substantially co-axially with the longitudinal axis of the roller bolt. The purpose of the at least one rebate is to provide an area in which the locking means may be positioned between the roller bolt and the nut member. The at least one rebate may also assist in improving the ease with which the roller hinge may be assembled.

The nut member may be of any suitable size, shape or configuration. The nut member may be adjustable by hand, by using a tool, or by a combination thereof. Thus, in a preferred embodiment of the invention, the nut member is provided with a tool engagement portion to facilitate the use of a tool to adjust the nut. Any suitable tool engagement portion may be provided, although in a preferred embodiment of the invention, the nut member may be provided with a portion having a hexagonal cross-section to enable a spanner, wrench, or the like to be used to adjust the position of the nut member relative to the roller bolt. Preferably, the nut member is provided with a complementary threaded portion adapted to engage with the threaded portion of the roller bolt. In preferred embodiments of the invention, the roller bolt is provided with a threaded portion on the outer surface of the roller bolt. Thus, in this embodiment, the nut member is provided with a threaded portion on an inner surface thereof.

In some embodiments, the nut member may be provided with means for retaining the locking means in place during use. Any suitable means may be provided, although it is preferred that the means for retaining the locking means are located on an inner surface of the nut member. Any suitable means for retaining the locking means may be provided, although it is preferred that the means for retaining the locking means may comprise one or more recesses, channels, depressions, grooves or the like into which at least a portion of the locking means may be received and retained during use. In a preferred embodiment, the means for retaining the locking means comprises an annular groove that extends substantially entirely about the inner circumference of the nut member.

The locking means may be of any suitable form. Preferably, however, the locking means comprises one or more biasing members adapted for movement between a locked condition in which the nut member is locked against rotation relative to the roller bolt and an unlocked condition in which the nut member is freed for rotation relative to the roller bolt. Any suitable biasing member may be used, such as, but not limited to, one or more springs, clips or the like, or a combination thereof. In some embodiments, the locking means may comprise a locking member associated with a biasing member, such as a spring, clip or the like.

The biasing of the locking means between the locked condition and the unlocked condition may be achieved manually, by using a suitable tool, or by a combination of the two. However, as the locking means is positioned between the roller bolt and the nut member, it is necessary to provide access means to allow a user to gain access to the locking means in order to bias the locking means between the locked and unlocked conditions.

Any suitable access means may be provided. Preferably, however, the access means are provided on the nut member, such that access to the locking means may be gained through the access means. The access means may be of any suitable form, although in some embodiments of the invention, the access means may comprise an opening in a wall of the nut member through which access to the locking means may be obtained. In one embodiment of the invention, the locking means may comprise a spring clip which, in the locked condition is biased so as to extend at least partially into the opening in the nut member. By extending at least partially into the opening, the spring clip prevents rotation of the nut member relative to the roller bolt in either direction.

To bias the spring clip into the unlocked position, a user will push the portion of the spring clip that extends into the opening using a finger or tool to overcome the natural bias of the spring clip until no part of the spring clip is within the opening. At this point, the user may rotate the nut member in the desired direction to adjust the height of the one or more panels. In order to return the spring clip to the locked condition (and thereby prevent unwanted rotation of the nut member), the nut member may be rotated until the spring clip is permitted to again become biased into the opening. Thus, as the spring clip is prevented from rotating, it is envisaged that the nut member must be rotated approximately 360° so that the spring clip may be returned to the locked condition.

In an alternative embodiment of the invention, the locking means may comprise a spring- loaded member which, in the locked condition is biased by a spring so as to extend at least partially into the opening in the nut member. By extending at least partially into the opening, the spring-loaded member prevents rotation of the nut member relative to the roller bolt in either direction. In a preferred embodiment of the invention, the spring- loaded member comprises a body and one or more projections extending therefrom, the one or more projections adapted to extend at least partially into the opening.

To bias the spring-loaded member into the unlocked position, a user will push the portion of the spring-loaded member that extends into the opening using a finger or tool to overcome the natural bias of the spring until no part of the spring-loaded member is within the opening. Preferably, this is achieved by pushing the spring-loaded member upwardly against the natural bias of the spring such that the spring-loaded member is received at least partially within a cavity located between the inner surface of the nut member and the outer surface of the roller bolt. At this point, the user may rotate the nut member in the desired direction to adjust the height of the one or more panels. In order to return the spring- loaded member to the locked condition (and thereby prevent unwanted rotation of the nut member), the nut member may be rotated until the spring-loaded member is permitted to again become biased into the opening. Thus, as the spring-loaded member is prevented from rotating, it is envisaged that the nut member must be rotated approximately 360° so that the spring-loaded member may be returned to the locked condition. If height adjustment is required wherein a 360° rotation of the nut member is not sufficient, it is envisaged that additional 360° rotations of the nut member may be performed until the panels are adjusted to the desired height. It will be appreciated that if a adjustments to the height of the panels are required that would involve a rotation of the nut member by less than 360°, one or more further openings may be provided in the nut member into which the spring clip may be biased. For instance, providing a pair equally spaced openings will enable 180° of rotation between locked positions. Similarly, three equally spaced openings will enable 120° of rotation between locked positions, and so on.

In another aspect, the invention resides broadly in a roller hinge for a folding door, window or similar closure having one or more panels, the roller hinge comprising a roller bolt having a threaded portion at a lower end thereof, a nut member adapted to be threaded onto the threaded portion of the roller bolt and locking means positioned between the roller bolt and the nut member, wherein the locking means is biased between a locked condition in which the nut member is locked against rotation relative to the roller bolt and an unlocked condition in which the nut member is freed for rotation relative to the roller bolt.

In yet another aspect, the invention resides broadly in a roller hinge for a folding door, window or similar closure having one or more panels, the roller hinge comprising a roller bolt having a threaded portion at a lower end thereof, a nut member adapted to be threaded onto the threaded portion of the roller bolt, the nut member including an opening in a wall thereof, and locking means positioned between the roller bolt and the nut member and accessible through the opening, wherein the locking means is biased between a locked condition in which the nut member is locked against rotation relative to the roller bolt and an unlocked condition in which the nut member is freed for rotation relative to the roller bolt.

In a further aspect, the invention resides broadly in a nut assembly for use in a roller hinge having a depending member with a threaded portion at a lower end, the nut assembly comprising:

a nut member adapted to be threaded onto the threaded portion of the depending member, the nut member including an opening in a wall thereof,

locking means positioned between the roller bolt and the nut member and accessible through the opening, the locking means being biased between a locked condition in which the nut member is locked against rotation relative to the roller bolt and an unlocked condition in which the nut member is freed for rotation relative to the roller bolt, and wherein the nut member includes an annular groove in an inner surface thereof adapted to receive and retain at least a portion of the locking means during use.

In a still further aspect, the invention resides broadly in a roller hinge for supporting at least one panel from a lower track, the roller hinge comprising

a carriage adapted to travel on the track;

a supporting member operatively extending from the carriage, the supporting member having a threaded lower end;

a nut member adapted to be threaded onto the threaded end of the supporting member;

at least one hinge leaf pivotally mounted on the supporting member and adapted to be fixed to a respective panel; and

locking means positioned between the roller bolt and the nut member and adapted to releasably lock the nut member against rotation relative to the roller bolt.

Any suitable supporting member may be provided. However, in a preferred embodiment of the invention, the supporting member comprises a roller bolt.

The carriage may be of any suitable form, and a skilled addressee will understand that the exact construction of the carriage is not critical. However, it is envisaged that the carriage may comprise at least one wheel to facilitate movement of the carriage relative to the track.

It will be understood that the term "lower track" is used to refer to a track located at a lower extremity of the door, window or similar closure. For instance, for a window, the lower track may refer to a track located on a window sill, while for a door, the lower track may refer to a track located on or adjacent the floor or ground.

In another aspect the invention resides broadly in a carrier hinge assembly comprising a roller hinge according to one or more aspects of the invention and a carriage. Preferably, the carriage comprises one or more wheels adapted to facilitate movement of the carriage along a track. The roller hinge may be formed integrally with the carriage or may be formed separately to the carriage and adapted for fixed or removable connection thereto. In a preferred embodiment of the invention, the roller bolt is formed integrally with the carriage.

Although the present invention has been described with particular reference to its use in connection with the lower track of a folding window or door assembly, it will be understood by those skilled in the art that the present invention could equally be used as a hanger hinge adapted to be used in connection with the upper track of a folding window or door assembly. Brief Description of the Drawings.

An embodiment of the invention will be described with reference to the following drawings in which:

Figure 1 illustrates an exploded perspective view of a carrier hinge assembly including a roller hinge according to an embodiment of the present invention;

Figure 2 illustrates a cross-sectional view of a carrier hinge assembly including a roller hinge according to an embodiment of the present invention;

Figure 3 illustrates a partial cross-sectional view of a roller hinge according to an embodiment of the present invention;

Figures 4-6 illustrates steps in the height adjustment of a roller hinge according to an embodiment of the present invention;

Figure 7 illustrates a perspective view of a folding door assembly including a number of carrier hinge assemblies according to an embodiment of the present invention.

Figure 8 illustrates an exploded perspective view of a carrier hinge assembly including a roller hinge according to an embodiment of the present invention; Figure 9 illustrates a partial cross-sectional view of a roller hinge according to an embodiment of the present invention;

Figure 10 illustrates a partial cross-sectional view of a roller hinge according to an embodiment of the present invention; and

Figures 1 1-13 illustrate steps in the assembly of a roller hinge according to an embodiment of the present invention.

Detailed Description of the Drawings.

It will be appreciated that the drawings have been provided for the purposes of illustrating preferred embodiments of the present invention and that the invention should not be considered to be limited solely to the features as shown in the drawings.

In Figure 1 there is illustrated an exploded perspective view of a carrier hinge assembly 10 including a roller hinge 1 1 according to an embodiment of the present invention. The carrier hinge assembly 10 includes a carriage 12 having a plurality of wheels 13 to facilitate the movement of the carriage 12 relative to a sill or floor track (not shown).

A roller bolt 14 extends upwardly from the carriage 12, the roller bolt 14 including a threaded portion 15 at a lower end thereof, and an axially extending slot or rebate 16 in a surface of the roller bolt 14 into which a locking means in the form of a spring clip 17 is positioned during use.

A nut member 18 having an internal thread (obscured) is shown in this Figure. In use the nut member 18 is threaded onto the threaded portion 15 of the roller bolt 14, with the spring clip 17 positioned therebetween. The nut member comprises an opening 24 in a wall thereof. When assembled, the spring clip 17 extends into the opening 24 due its natural bias. When the spring clip 17 extends into the opening 24, the roller hinge 1 1 is in the locked condition, as the nut member 18 is precluded from rotation.

The roller hinge 1 1 illustrated in Figure 1 is provided with three hinge leaves 19 which are positioned above one another on the roller bolt 14. The hinge leaves 19 are spaced apart from one another by positioned spacers 20 between adjacent hinge leaves 19. The roller hinge 1 1 further comprises a cap 21 which has an enlarged portion 22 and an engagement portion 23 depending from the enlarged portion 22, the engagement portion 23 being adapted for insertion and retention in a bore (obscured) in the upper end of the roller bolt 14. The enlarged portion 22 of the cap 21 prevents the hinge leaves 19 from unintentionally being removed from the roller hinge 1 1.

In Figure 2, a cross-sectional view of a carrier hinge assembly 10 including a roller hinge 1 1 according to an embodiment of the present invention is shown.

It may be seen in this Figure that the carriage 12 comprises vertical wheels 13a and horizontal wheels 13b adapted to be brought into contact with the base and side of a track (not shown), respectively. The carriage 12 of Figure 2 is formed integrally with the roller bolt 14.

It may further be seen that the enlarged portion 22 of the cap 21 is of sufficient size to prevent the hinge leaves 19 from being removed from the roller bolt 14 without first removing the cap 21. In Figure 2, the nut member 18 has been threaded onto the roller bolt 14 and the spring clip 17 is biased into the locked condition wherein the spring clip 17 extends into an opening 24 in the nut member 18. In order to rotate the nut member 18 so as to adjust the height of the hinge leaves 19, it would first be necessary to bias the spring clip 17 into the unlocked condition by pushing the spring clip 17 inwardly towards the surface of the roller bolt 14. Once in this position, the nut member 18 may be rotated in either direction as desired.

This arrangement is shown in more detail in Figure 3 in which it may be seen that the spring clip 17 is located in the rebate 16 in the surface of the roller bolt 14. A portion of the spring clip 17 is adapted to be retained in an annular groove 25 in the inner surface of the nut member 18.

In this Figure, the spring clip 17 is illustrated in the locked condition, wherein part of the spring clip 17 extends into the opening 24 in the nut member 18, thereby precluding rotation of the nut member 18. In order to adjust the height of the panels (not shown) a user would be required to insert an object (such as a finger or tool) into the opening 24, and bias the spring clip into the unlocked condition by overcoming the natural bias of the spring clip 17 and pushing it towards the surface of the roller bolt 14. When held in this position, the nut member 18 may be rotated in either direction as desired.

Turning now to Figures 4 to 6, the steps in the height adjustment of a roller hinge 1 1 according to an embodiment of the present invention is shown.

In Figure 4, the nut member 18 is abutting the carriage 12 meaning that the roller hinge is at its lowest possible height setting. If it is desired to raise the position of the roller hinge 1 1, the spring clip 17 must be biased into the unlocked condition, and the nut member 18 must be rotated. After one full rotation of the nut member 18, the opening 24 in the nut member 18 will again be brought into alignment with the spring clip 17 in the axial slot 16, and the spring clip 17 will automatically spring back into the locked position as a result of its inherent resilient bias. One or more rotations of the nut member 18 may be required to adjust the height of the roller hinge to that illustrated in Figure 5. If the height of the panels (not shown) is still not sufficient, the roller hinge 11 shown in Figure 5 may be adjusted upwardly again. Again, the spring clip 17 must be biased into the unlocked condition, and the nut member 18 must be rotated. After one full rotation of the nut member 18, the opening 24 in the nut member 18 will again be brought into alignment with the spring clip 17 and the spring clip 17 will bias into the locked position. One or more rotations of the nut member 18 may be required to adjust the height of the roller hinge to that illustrated in Figure 6.

In Figure 6, the height of the roller hinge 1 1 has been adjusted such that the uppermost hinge leaf 19 abuts the cap 21, meaning that the upper limit of height adjustment has been reached.

It may be seen in Figure 6 that the hinge leaves 19 comprise a tubular body 19a adapted to slide over the roller bolt 14 and a leaf portion 19b extending outwardly from the body 19a and adapted for connection to a panel (not shown).

In Figure 7 there is shown a perspective view of a folding door assembly including a number of carrier hinge assemblies 10 according to an embodiment of the present invention. In this Figure four door panels 26 are interconnected by a plurality of roller hinges 11.

The carrier hinge assemblies 10 are adapted to move along a lower track 27. An upper track 28 is also provided in the embodiment shown in Figure 7.

As shown in the enlarged portion of Figure 7, the carriage 12 is associated with the lower track 27. If the height of the door panels 16 requires adjustment, the spring clip 17 may be moved into the unlocked condition and the nut member 18 may be rotated is described in connection with Figures 4 to 6. In this way the position of the door panels 26 may be adjusted as desired.

In Figure 8 there is shown a perspective exploded view of a carrier hinge assembly 50 including a roller hinge 51 according to an embodiment of the present invention. The carrier hinge assembly 50 includes a carriage 52 having a plurality of wheels 53 to facilitate the movement of the carriage 52 relative to a sill or floor track (not shown).

A roller bolt 54 extends upwardly from the carriage 52, the roller bolt 54 including a threaded portion 55 at a lower end thereof, and an axially extending slot or rebate 56 in a surface of the roller bolt 54 into which a locking means in the form of a spring-loaded member 57 is positioned during use.

A nut member 58 having an internal thread (obscured) is shown in this Figure. In use the nut member 58 is threaded onto the threaded portion 55 of the roller bolt 54, with the spring-loaded member 57 positioned therebetween. The nut member 58 comprises an opening 59 in a wall thereof. As can be seen in the magnified portion of Figure 8, the spring-loaded member 57 comprises a body 60 with a spring 61 associated with one end thereof. The spring-loaded member 57 further comprises a projection 62 extending outwardly from the body 60. When assembled, the projection 62 extends into the opening 59 due the natural bias of the spring 61. When the projection 62 extends into the opening 59, the roller hinge 51 is in the locked condition, as the nut member 58 is precluded from rotation.

The roller hinge 51 illustrated in Figure 8 is provided with a hinge leaf 63 which is positioned on the roller bolt 54.

The roller hinge 51 further comprises a cap 64 which has an enlarged portion 65 and an engagement portion 66 depending from the enlarged portion 65, the engagement portion 66 being adapted for insertion and retention in a bore (obscured) in the upper end of the roller bolt 54. The enlarged portion 65 of the cap 64 prevents the hinge leaf 63 from unintentionally being removed from the roller hinge 51.

In Figure 9, a partial cross-sectional view of a roller hinge 51 according to an embodiment of the present invention is shown. In this Figure, it may be seen that the body 60 of the spring-loaded member is located in the rebate 56 in the surface of the roller bolt 54. The spring-loaded member is held in position by the natural bias of the spring 61..

In this Figure, the spring-loaded member is illustrated in the locked condition, wherein the projection 62 extends into the opening 59 in the nut member 58, thereby precluding rotation of the nut member 58. More specifically, the nut member 58 is prevented from rotating as the projection 62 will abut an inner surface 67 of the nut member 58 if rotation of the nut member 58 is attempted. This abutment prevents rotation of the nut member 58.

In order to adjust the height of the panels (not shown) a user would be required to insert an object (such as a finger or tool) into the opening 59, and bias the spring-loaded member into the unlocked condition by overcoming the natural bias of the spring 61 and pushing the body 60 upwardly into a cavity 68 within the between the nut member 58 and the roller bolt 54. When held in this position, the projection 62 is removed from the opening 59, and the nut member 58 may be rotated in either direction as desired. This arrangement is illustrated in Figure 10.

In Figures 1 1 -13 there are shown steps in the assembly of a roller hinge 51 according to an embodiment of the present invention. In Figure 1 1, the spring-loaded member 57 is positioned in the rebate 56 in the outer surface of the roller bolt 54. As shown in the Figure, the rebate 56 includes a first region 56A and a second region 56B, the depth of the first region 56A below the surface of the roller bolt 54 being greater than that of the second region 56B. The spring-loaded member 57 is initially placed in the first region such that at least a portion of the nut member 58 may pass over the spring-loaded member 57 during assembly.

In Figure 12, the nut member 58 has been moved along the roller bolt 54 until it is positioned substantially above the spring-loaded member in the first region 56A of the rebate.

In Figure 13, further movement of the nut member 58 causes the spring 61 to abut an inner surface of the nut member. Thus, as the nut member 58 continues to move relative to the roller bolt 54, the spring-loaded member 57 also moves relative to the roller bolt 54. Once the nut member 58 is brought into contact with the screw threaded portion 55 at the end of the roller bolt 54, the nut member 58 may be brought into screw-threaded engagement with the screw threaded portion 55, thereby completing the assembly of the roller hinge 51.

The present invention provided numerous advantages. For instance, the positive locking action of the present invention means that, even during repeated opening and closing of the door or window, the nut member of the present invention is unlikely to loosen. As a result, unwanted changes in the height of the panels over time are less likely to occur. In turn, this leads to fewer adjustments needing to be made to the height of the panels. In addition, even though the locking action of the present invention results in a superior product, the present invention is also simple to use and allows for rapid adjustments to the height of the panels when required or desired. Further, the present invention requires only a relatively small number of parts, making fabrication of the invention easier and less expensive. Those skilled in the art will appreciate that the present invention may be susceptible to variations and modifications other than those specifically described. It will be understood that the present invention encompasses all such variations and modifications that fall within its spirit and scope. For example, although the illustrated embodiment shows an adjustable roller hinge adapted to be affixed to a lower portion of a folding window or door, the roller hinge of this invention could also be applied, with suitable modification, to an upper portion of a folding window or door. It will be clearly understood that, if a prior art publication is referred to herein, this reference does not constitute an admission that the publication forms part of the common general knowledge in the art in Australia or in any other country.

Throughout this specification, the term "comprising" and its grammatical equivalents shall be taken to have an inclusive meaning unless the context of use indicates otherwise.