Screen system

A screen system for use with a sliding panel of a window or door is used to screen an opening as the sliding panel or door is opened. The screen is attached to the edge of the sliding panel adjacent the opening, and is wound onto a spindle. The spindle is rotatably mounted adjacent the screen opening around which the screen is wound so that the screen can be unwound from or wound onto the spindle. A cord is connected between the sliding panel and the spindle pulley via an idler pulley. In this arrangement the spindle is caused to rotate so as to wind the screen back onto the spindle as the sliding panel is slid towards the closed position. While the screen is wound off the spindle, the cord is wound onto the spindle pulley and vice versa. As the A tension adjustment arrangement can also be provided that is configured to adjust the tension in the cable as the screen is wound and unwound from the spindle due to the change in diameter of the cord around the spindle pulley.

PRIORITY DOCUMENTS

The present application claims priority from Australian Provisional Patent Application No. 2013902396 titled “An Improved Screen System” and filed on 28 Jun. 2013; the entire content of which is hereby incorporated by reference.

TECHNICAL FIELD

The present invention relates to a screen system used with opening panels and in particular to providing a moving screen to screen an opening as the panel is moved from a closed position to an open position.

BACKGROUND

It is a common requirement to provide a screen in relation to doors or windows. For example, in the case of a window, there may be provided a sliding window panel which is used to open the window. Conventionally, a screen is used to prevent ingress of insects or debris while at the same time providing ventilation. Also, screens are generally open mesh which also provides visibility through the screen.

In the case of doors, it is common to use a second door as the screen.

One disadvantage in the case of windows is that existing screen systems cover one half or a number of portions of the window. They will have permanently installed screens so that a portion of the window provides a clear view while for the remainder of the window, the user will have to look through the window and screen. It would be much more desirable to have simply glass unobstructed by any screens.

Also, the screens are normally provided in a frame which is then mounted to the window. This then results to restricted access to the window for the purpose of cleaning or other maintenance.

Sliding doors are common, but in these cases it is necessary to have both a sliding door with glass and a second sliding door with the screen. In certain circumstances it could be desirable for a screen to move into the opening as the door is opened

There is thus a need to provide a screen system integrated with a window or door opening that eliminates some of these disadvantages, or at least provides a useful alternative to existing systems.

SUMMARY

According to a first aspect of the present invention, there is provided a screen system for use with a sliding panel of a window or door to screen an opening as the sliding panel or door is opened, the system comprising:

a frame,

a sliding panel housed within the frame and comprising a first edge, wherein the sliding panel is slideable between a closed position and an open position to define an opening adjacent the first edge;

a roller assembly comprising:a screen attached to the first edge of the sliding panel;a spindle around which the screen is wound and rotatable mounted adjacent the first edge when the sliding panel is in the closed position so that the screen can be unwound from the spindle as the sliding panel is opened, and wound back onto the spindle as the sliding panel is closing; anda spindle rotation assembly for rotating the spindle;

an idler pulley located within the frame housing;

at least one operative means connected between the sliding panel and the spindle rotation assembly via the idler pulley, that causes the spindle to rotate so as to wind the screen back onto the spindle as the sliding panel is closing.

In one form, the screen system further comprises:

a tension adjustment arrangement comprising a mount housing that houses the idler pulley, a spring anchor securable with respect to the frame, and a spring secured between the mount housing and the spring anchor wherein the tension adjustment arrangement is configured to adjust the tension in the operative means as the screen is wound and unwound from the spindle.

In a further form, the frame comprises an upper slot, and the tension adjustment arrangement is located and secured in the upper slot.

In as further form, the upper slot comprises two side walls and the spring anchor is as block with tapered sides, and the tension adjustment further comprises a U shaped receiving block that is fastened to the spring anchor so that the tapered sides of the spring anchor force the walls of the a U shaped receiving block outwards to generate an the interference fit with the two side walls of the upper slot to secure the spring anchor in the upper slot.

In one form, the frame housing comprises a side frame member that substantially houses the roller assembly, and the side frame member has a removable cover, and the spindle comprises a rod portion onto which the screen is wound, and a retractable end assembly having an extended configuration and a retracted configuration, such that the length of the spindle in the retracted configuration is less than the length of the spindle in the extended configuration to allow removal of the spindle from the side frame member.

In a further form, the retractable assembly comprises a tube, a spring, a barrel and a plug, the tube comprising an open end for receiving the spring and barrel, and the barrel comprises a barrel lock aperture for receiving the plug, and a barrel projection, and the tube comprises a first cut out portion aligned with the barrel lock aperture, and second cut-out portion aligned with the barrel projection, such that when the plug is inserted through the first cut-out portion and into the barrel lock aperture, an end of the barrel extends beyond the second end of the tube and the retractable assembly is locked in the extended configuration, and when the plug is removed, the barrel can be at least partially retracted into the tube.

In one form, the spindle rotation assembly comprises a spindle pulley axially mounted to one end of the spindle.

In a further form, the spindle pulley comprises an axial aperture, and the spindle rotation assembly rotatably mounts the spindle and comprises a mounting block with a front face that faces the first edge of the sliding panel, a curved cut-out portion for receiving the spindle pulley, an axial projection located within the curved cut-out portion which in use projects into the axial aperture of the spindle pulley, and channel from the front face to the curved cut-out portion to guide the operative means onto the spindle pulley.

In a further form, the spindle rotation assembly further comprises a guide roller, and the channel comprises a straight portion and an angled portion, wherein the guide roller is located at the junction of the straight portion and angled portion and partially projects into the channel to guide the operative means as it is wound and unwound from the spindle pulley.

In a further form, the top surface of the mounting block comprises a flange and a channel, and the mounting block is supported by a top frame member of the frame that comprises a slot for receiving the flange and a pair of projections that are received in the channel.

In one form, the screen is removably attached to the first edge.

In one form, the frame comprises a first side frame member, a second side frame member, an upper frame member and a lower frame member, and each of the frame members are extrusions, wherein the upper frame member comprises an upper slot, and the lower frame member comprises a lower slot wherein the upper slot and lower slot are aligned and the sliding panel slides within the upper slot and the lower slot, and the roller assembly is substantially housed within the second side frame member and comprises a screen aperture through which the screen is unwound and wound onto the spindle, and a screen guide extending from the upper slot to the lower slot to guide the screen onto and off the spindle.

In the following description, like reference characters designate like or corresponding parts throughout the figures.

DESCRIPTION OF EMBODIMENTS

Various embodiments of a screen system for integration into a frame of a window or door opening to allow the window or door opening to be covered when in an open position will now be described. The invention relates to a movable screen for use with as slideable panel wherein the screen moves to cover the opening as the panel is moved between an open and closed position. The screen may be attached with respect to the panel so that as the panel is moved from its closed to open position, the screen is drawn across the opening. The embodiments described below will be in relation to a window frame with a sliding window panel that slides over a fixed pane of glass. However, it will be realised that the invention will be suited to other applications such as sliding doors or in fact any situation where a panel is to be slid from a closed position to an open position where the opening is required to be covered by a screen. Further, the system could be further adapted for use with two sliding windows rather than a fixed and sliding window arrangement.

FIG. 1shows a window frame assembly100that comprises a pair of side frame members—first side frame member101and second side frame member102, and an upper frame member103and a lower frame member104. These frame members101,102,103and104provide a rectangular window frame which can be mounted in an appropriate cavity within a building such as a house. One side of the window frame100has a permanently mounted first pane of glass106. This first pane of glass106covers half of the window frame100. Mounted within the window frame100for slideable movement between an open and closed position is a slideable window panel107. The window panel107has a frame108and a pane of glass109within the frame108.

As seen inFIG. 1, the window panel107has been slid to an open position. A roller assembly200is rotatably mounted adjacent the first side window frame member101, being the side member adjacent the opening formed by movement of the window panel107. The roller assembly200comprises a screen201wound on to a spindle206. A spindle rotation assembly230(not shown inFIG. 1) is used to rotatably mount the spindle206with respect to the window frame100. The end of the screen201is attached to a first edge of the window panel207which in this embodiment is a post extending above and below the horizontal frame members of the window panel. The screen may be fixed or secured to the first edge or removably attached to the first edge (e.g. using hooks or removable fasteners) so that a user can have the window fully open without a screen at all. A pair of slots, comprising an upper slot208and a lower slot209, is formed in the respective upper and lower frame members extending from the adjacent the side member102. The post207extends through the slots208,209so that it is above and below lower frame members103,104. Pulleys202and203are mounted to each end of the spindle206. As will be described below, these upper and lower pulleys202and203are used to rotate the spindle206.

An operative means211such as cord, cable, belt or other linkage is secured at the first end212or distal end with respect to the roller assembly, to the post207. That is the operative means is connected between the panel and the roller assembly in such a way to cause the roller assembly to rotate as the panel is moved to a closed position to thereby wind the screen onto the spindle. It extends around an idler pulley210which reverses the direction of the cord and directs it back towards the roller assembly where it wraps around and is attached to pulley202. The idler pulley210is mounted using a tension adjustment arrangement220that comprises a spring215secured or anchored between a mount housing214and a spring anchor216which is securable to the frame. In this embodiment, the spring anchor comprises a bracket mounted to the upper frame member103. The tension adjustment arrangement is arranged so that the idler pulley210applies tension to the cord211, and compensates for a change in the tension of the cord as the cord is wound and unwound off pulley202. An idler pulley210and associated spring215and cord211are also provided on the lower frame member104but are not shown inFIG. 1. In one embodiment, the spindle rotation assembly230includes is a mounting bracket secured with respect to the side member102and with apertures within which the spindle206is rotatably mounted. In another embodiment, the spindle rotation assembly230includes a bracket positioned underneath the pulley202so that it is between the pulley202and the screen201.

In operation, with the window panel107fully closed the entire screen201is wound onto the spindle206. As the window panel107is opened, screen201will be unwound from the roller assembly200so as to cover the opening. The window panel107will pull the screen201so as to unwind it from the roller assembly200. At the same time, the pulleys202and203are rotated and upper and lower cords211are wound onto each of the pulleys202and203. Note that in some embodiments, only a single upper or lower spindle rotation assembly, rather than both upper and lower spindle rotation assemblies, is used.

When the window panel107is closed, the cords211engage with, and cause the pulleys202and203to rotate and thereby rewind the screen201onto the roller assembly200. The pulleys202and203have a diameter that results in the required rotation rate of the roller assembly200to roll the screen201onto the roller assembly200at the same rate at which the window panel107is being moved. In this way the screen201is itself retracted at the same rate as the window panel107is closed.

This mechanism thus has the advantage that extending and retracting the screen does not require any form of spring based tensioning arrangements to rewind the screen onto the roller assembly. Instead the arrangement guides an operative member around a pulley provided with a tension adjustment arrangement. This provides a smooth mechanism to extend and retract the screen. When the window panel is open and thus the screen is an extended position, closing the window is translated into a pulling action on the cord to unwind the cord off the first pulley, and this drives the rotation of the spindle to wind the screen back on. Conversely, opening the window to extend the screen rotates the spindle and pulley to wind the cord back onto the first pulley.

FIG. 2shows another embodiment of a window frame300, comprised of a first side frame member301, a second side frame member302, an upper frame member303and a lower frame member304which support the fixed pane of glass106and slideable window panel107(omitted for clarity) and house the roller assembly and related components. The terms upper and lower are with respect to the view shown inFIG. 2, and thus the upper frame member and lower frame member could equivalently be referred to as third and fourth frame members. In this embodiment each of the window frame members are extruded frame members, and may be formed of single extruded sections, or assembled from several extruded components. In this embodiment the roller assembly including the spindle206and screen is housed within the second side frame member302behind a removable side frame member308. The slideable window panel107slides laterally within a first lower channel209, with the slideable window panel being in a closed position when on the left and the fixed pane of glass106is located in a second lower channel portion349(on the right in the view shown inFIG. 2). The screen may be fixed or secured to the first edge or post of the slideable window panel207or removably attached to the first edge or post (e.g. using hooks or removable fasteners) so that a user can have the window fully open. When the screen is detached it may be secure to attachment points provided on the housing to facilitate later reattachment to the slideable window panel107.

In this embodiment, the view of the window frame is from the outside, so that the user can slide the screen from the inside, and access to the roller assembly by removal of the movable side frame member308is via the outside. However, it will be understood that this arrangement could be reversed (i.e. the view could be from the inside, allowing inside access to the roller assembly) and the only substantial change would be movement of a handle307for sliding the slideable panel and screen. In this embodiment, the window frame members are configured to receive the fixed pane of glass106, and a slideable window panel107comprising a pane of glass109and frame108. In other embodiments, the window frame100shown inFIG. 1could be mounted within the window frame member300shown inFIG. 2.

FIGS. 3A, 3B, and 3Cshows a top view of the roller assembly and slideable window panel in a closed state, opening state and fully open state, respectively, of the window frame illustrated inFIG. 2with the upper frame103removed. Referring toFIG. 3A, the fixed pane of glass106is mounted between the first side frame member301and a central member305, in respective pane receiving channels316and306. InFIG. 3Athe window is in a closed position (or state) with the slideable window panel107extending across the window opening105from the central member305to the second side member302. The roller assembly200is housed within the second side frame member302. In this closed state, the screen201is fully wound onto the spindle206, and only a small portion extends, within the housing of the second side frame member, from the spindle, past screen guide323, to the edge of the window panel (i.e. post207) where it is attached. From a top view the screen is attached to the post at the same attachment point for the first end212of the operative member, which in this embodiment is a cord211.

In contrast to the screen which is fully retracted or fully wound onto the spindle inFIG. 3A, the operative member, which in this embodiment is a cord211, is extended or unwound off the spindle to its maximum extent. In this embodiment, the cord211has one end212attached to an attachment point on the post207and extends toward the distal end of the slideable window panel (distal with respect to the roller assembly and spindle206), where it passes around an idler pulley210of a tension adjustment arrangement220. The idler pulley210redirects the cord back towards the second side frame member302where it passes around a guide roller237that guides the cord211onto (and thus around) the first pulley202of the spindle rotation assembly230where the second end of the cord is anchored or secured to the first pulley202. The spindle rotation assembly230is shown in more detail inFIGS. 4, 5A, 5B and 6A.6B, and6C.

As shown inFIG. 3B, when the window is opening, for example by a user moving handle307located on the distal edge of the slideable window panel107towards the first side frame member301, the screen201is pulled off the spindle206and extends across the opening205. As the screen is extended and wound off the spindle, the spindle rotates anticlockwise as indicated by the arrows inFIG. 3B, and this drives rotation of the pulley202to retract the cord211, and via idler pulley210, wind it back onto the pulley202.

FIG. 3Cshows the slideable window107in the fully open position with the screen201fully unwound from the spindle, and extends across the window opening205. As the screen is fully unwound the cord211is fully wound onto the pulley202. If the window is not closed, for example by grasping handle307which is adjacent the first side frame member and moving it towards the second side frame member302. As the cord211is fixed at one end212to an anchor point on the proximal edge of the slideable window panel107, this movement pulls the anchored end212of the cord211towards the second side frame member, and via idler pulley210, pulls the cord to unwind it off the pulley202. This unwinding of pulley202thus drives clockwise rotation of the spindle206to wind the screen back onto the spindle206.

During sliding of the window panel107, the cord211is wound onto and off the spindle pulley202. This results in a change in the diameter of the cord211wrapped around the spindle pulley202which can change the tension in the cord. This change in diameter can alternatively be viewed as a change in the length of the cord wrapped around the spindle pulley202. Thus, to compensate for any change in tension in the cord211(or more generally the operative means used), the cord is passed through or around a tension adjustment arrangement220. With reference toFIGS. 3A, 4, 8A and 8B, the tension adjustment arrangement220is located and secured in the upper slot208of the upper frame member303, and comprises a proximally located mount housing214that is connected to a distally located spring anchor216via a spring215. The mount housing214houses a proximally located idler pulley210which rotates around a shaft of a fastener261, which has an axis substantially parallel, to the spindle axis, and a distally located first anchor point262which anchors the proximal end of the spring using a fastener262. The distal end of the spring215is anchored to an anchor point263via a fastener located at the proximal end of the spring anchor216. The spring anchor216comprises an approximately rectangular block with tapered side edges267268, with the width at the upper edge greater than the width at the lower edge (with respect to the window frame300). The tapered block is received in a L1shaped receiving block266, and secured in place via fasteners264265. This is further illustrated inFIG. 8Cthat illustrated the tapered block of the spring anchor216and the receiving block266within the upper slot208of the upper frame member303.

In this embodiment, the spring anchor216is seemed to the frame assembly300using an interference fit between the walls of the U shaped receiving block266and the walls of the upper slot208of the upper frame member303. As illustrated inFIG. 8C, the spring anchor216rests against the lower or inner surface of the wall engaging panel within the upper slot208. The U shaped receiving block266is then brought under the spring anchor216and fasteners in the form of screws264and265are used to screw the receiving block266to the spring anchor so that the tapered sides267268of the spring anchor216force the walls of the U shaped receiving block outwards to generate an interference fit with the two side walls of the upper slot to secure the spring anchor in the upper slot. The use of an interference or frictional fit avoids the need to use adhesive or use fasteners such as screws or bolts that pass through or into the upper frame member, thus allowing the upper frame member to have an tin-interrupted exterior surface. However, in other embodiments, such arrangements could be used to secure the spring anchor216to the frame assembly300.

As the tension in the cord changes as a result of the change in the diameter of the cord around the pulley210, the length or extension of the spring215changes to compensate, resulting in lateral movement of the mount housing214, and more relevantly, the position of the idler pulley210with respect to the spindle pulley206. This compensation or accommodation of the change in tension occurs as the window is opened and closed, and facilitates smooth opening and closing operations whilst maintaining an acceptable amount of tension on the screen to prevent sagging.

In this embodiment the roller assembly200is adapted for removal from the frame. This is achieved through a combination of the design of both the spindle mounts and the second side frame member. As shown inFIGS. 6A to 6C, andFIGS. 7C and 7D, the second side frame member is constructed from two extrusions, in which the second extrusion is a removable side frame member308which can be removed to provide access to the removable roller assembly.

The removable roller assembly200shown inFIG. 3is shown in greater detail inFIGS. 4, 5A and 5B. An upper spindle rotation assembly230comprises an approximately L shaped mounting block231with a curved cut-out region230on the underside of the mounting block with a pulley axial projection233to receive the spindle pulley202, which rotates about the pulley axial projection233. A guide channel239for the cord211extends within the mounting block231from an aperture234on the front face238of the mounting block (when looking into the frame from the window opening) to the inner edge of the cut-out region so that the cord can be wound onto the pulley202. That is the front face faces the first edge or post207of the slideable panel107. The guide channel239comprises a straight portion (or section) followed by an angled portion or section) as shown as the dotted lines inFIG. 612. The top of the mounting block also comprises a cylindrical aperture236that extends down and intersects an edge of the guide channel239at the corner where the straight section means the angled section. The cylindrical aperture236receives a guide roller237that in use can rotate about a vertical axis. The guide roller237is located at the junction of the straight portion and angled portion and partially projects or extends into the guide channel239to guide the cord through the guide channel239and onto the spindle pulley202as it is wound and unwound from the spindle pulley

The lower side of the spindle pulley202comprises a spigot projection241that receives a fastener242for securing the spindle pulley to the mounting block231, by passing through an axial aperture in the pulley202and into a receiving aperture in the pulley axial projection233. The spindle206is a tube which receives an upper end cap243into the upper end of the spindle206. As can be seen inFIGS. 5A and 5Bthe upper end of the spindle comprises a cut-out portion to receive a side projection in the upper end cap243to lock it in place. The interior of the upper end cap243is shaped to mate with or engage with the spigot241on the spindle pulley202.

To enable removability of the roller assembly the spindle206comprises a rod portion onto which the screen is wound, and a retractable end assembly having an extended configuration and a retracted configuration. The length of the spindle in the retracted configuration is less than the length of the spindle in the extended configuration to allow removal of the spindle from the side frame member. In this embodiment the lower end of the rod portion of the spindle206receives the retractable assembly that is comprised of a lower end insert in the form a tube245, a spring248, a plug249and a substantially barrel shaped piece250.

The lower end of the spindle206comprises a first extended cut-out or slot244. The lower end insert245is a tubular cylinder with a closed top end and open lower end which is inserted into the lower end of the spindle206. The lower side wall of the cylinder comprise a first cut out or slot246and a second extended cut-out or slot247, which in this case is opposite the first cut-out or slot246and in use is aligned with the extended cut out on the lower end of the spindle. To facilitate this alignment the lower end of the spindle also comprises a locking cut out that receives to locking projection on the lower end of the lower end insert245. This allows alignment and prevents rotation of the lower end insert with respect to the spindle206.

The lower end of the lower end insert245is open and receives a spring248and the barrel shaped piece250. The barrel shaped piece250has a lock aperture251and a barrel projection252. The barrel lock aperture251is aligned with the first cut-out246of the lower end insert245and is designed to receive a matching locking plug249that fits into and extends out of the barrel lock aperture251. When the plug is inserted into the barrel, the lower end of the barrel extends beyond the second end of the tube245due to the action of the spring248. The barrel projection252is aligned with the second extended cut-out252of the lower end insert245and the extended cut-out244of the lower end of the spindle206. When the locking plug249is present, it passes through the first cut-out246and into the barrel250, initially at a level below the top edge of the first cut-out246. Thus the barrel250is able to be moved upwards (at least until the locking plug engages with and is stopped by the top edge of the first cut-out246, and be at least partially retracted into the tube245effectively reducing the length of the spindle and allowing removal. Rotation of the barrel is prevented by barrel projection252that moves upward in the extended cut-outs247and244. In this embodiment the spring248acts to push the barrel downwards to prevent retraction, and thus a tool such as a screw driver may be required to lever the barrel upwards, or to lever the locking plug, and thus the barrel, upwards and into the lower end insert245against the spring force. This arrangement has the advantage that the change in length of the spindle occurs in a portion that the screen is not wound onto, and thus the screen is unaffected. Other variations and arrangements could also be used to provide the change in length to provide the removability functionality.

The lower end of the spindle is mounted in a lower mounting arrangement270that comprises a block with a front face271and curved cut-out274leading to a base272. Like the mounting block231of the upper spindle rotation assembly, the lower mounting arrangement comprises a cut out for receiving a lower or second spindle pulley203that rotates about an axial projection. The front face faces the first edge or post207of the sliding panel107and comprises a channel273for guiding a cord211onto the second pulley203. The top of the pulley203is adapted to receive the lower end of the barrel250when it is in the extended position. For example the axial aperture of the pulley203may act as a receiving channel for the end of the barrel. Retraction of the barrel also retracts the barrel from the receiving channel.

FIGS. 6A and 6Bare first and second perspective views of the roller assembly with the removable side frame member308of the side frame member302. The removable side frame member308is an extrusion with a profile shown inFIG. 7D, and comprises a curved screen guide323attached to an L shaped arm portion324. This is attached at the other end to an inner panel325portion (the most distal portion of the removable side frame member308), and an inclined panel326and an exterior panel327. The exterior panel ends with a slot329. The lower mounting arrangement and profile of the second side frame member is shown inFIG. 7C. This illustrates the relative location of the guide roller237and screen guide323.

FIG. 6Cis a close up view of the top of the roller assembly shown inFIG. 6Aalso showing engagement attic removable side frame member with second extrusion of the second side frame member302. The mounting block231rests on the top edge of the inner panel325of the removable side frame member208. Additionally, the top surface of the mounting block231comprises a flange (or projection) in the upper right hand top edge of the mounting block231which is received in a corresponding slot (or ridge) formed in the upper frame member303(secFIG. 7B) to assist in supporting the mourning block23L The top surface of the mounting block also includes an upper channel235that in use receives a pair of projections in the top frame member. The second extrusion comprises an outermost wall engaging portion321with an interior panel322on one side and a slot projection or fin328that fits into the slot329of the removable side frame member308to support and hold it in place.

The arrangement of the upper spindle rotation assembly230and the second extrusion of the second side frame member308is further shown inFIG. 7A. This further illustrates the cord channel239, pulley202, and upper channel235,FIG. 7Bis a side view of the spindle rotation assembly and profile of the upper frame member303. The upper frame member303comprises a will engaging portion331from which downwardly extends an interior panel332and a central arm334which define the proximal end of the upper slot208(or channel) that the top edge of the slideable window panel207and cord211move within.FIG. 8Cfurther illustrates the profile of the upper frame member303, with the tension adjustment component220located in the upper slot208. The interior panel332is formed with a slot333(or shoulder or ridge) near the base of the interior panel to receive the flange in the top edge of the mounting block231, and extends downwards and ends with a hook at the lower end that is directed outwards and away from the upper slot208and towards the interior side of the window frame).

Parallel to the central arm334is another downward projection which ends with a ribbed portion337to form an upper window pane receiving channel351that is parallel to slot208. The fixed window pane106only resides in the distal half of the window pane receiving channel351, and thus the proximal half of the window pane receiving channel351is covered with a clipable panel335. This clips into a projection on the central arm334and ribs formed on the vertical edge adjacent the start of a lower panel336. The lower panel336then joins with the downwardly extending exterior panel338.

The mounting block231is slid into the end of the upper frame member303and is supported in place via the slot333that supports a projection or flanged top edge of the mounting block231. The mounting block231also includes an upper channel235to receive one or more projections339that extend down from the wall engaging panel331. These are used to allow the second side frame member to be screwed to the upper frame member. The one or more projections may be a pair of projections to receive and engage with a screw passed through the wall of the second side frame member to fix the second side frame member to the upper frame member. Similarly, the other end of the pair of projections may receive a screw passing through the first side frame member to fix the first side frame member to the upper frame member. The size of the upper channel is selected to accommodate this expansion of the one or more projections339. In some embodiments, the size of the channel could be selected so that the expansion of the one or more projections could lock into the walls of the upper channel to further support the mounting block231.

FIGS. 9 and 10A to 10Dfurther illustrate how the frame members are arranged with respect to each other to form the complete window frame.FIG. 9is a perspective view of the window frame without the upper frame member.FIG. 10Ais a perspective view of a cut away portion of the window frame illustrating cut away views of the upper frame member and lower frame member connected to the second side frame member.FIG. 10Bis an end view of the cut away portion of the window frame shown inFIG. 10A.FIG. 10Cis a top view of the lower frame member andFIG. 10Dis a perspective view of the first side frame member.

The first side frame member301comprises a wall engaging panel311from which an interior panel313extends. A projection312directed towards the interior of the window frame, extends from the join line of the wall engaging portion and the interior panel313. The interior panel extends inward towards the second frame member302, and ends at one end of orthogonal inner panel314. The inner panel314forms the surface that the slideable window panel107abuts against in the fully open position. The inner panel314is interrupted by pane receiving channel316that receives the fixed window pane106. A pane engaging portion315extends into the pane receiving channel316. On the other side of the pane receiving channel316, an inclined panel317(similar to inclined panel326) extends to meet the exterior panel318which extends back towards the wall engaging panel (and is orthogonal to).

The lower frame member304comprises a wall engaging panel341an interior panel that extends upwards from the wall engaging panel341and ends in an outwardly directed hook section similar to interior panel322of the upper frame member303. The lower slot209(or channel) that the lower portion of the slideable window panel107slides within is formed by the interior panel322on one side, and a central arm345on the other. The central arm345then also forms one side of a window pane receiving channel349that is parallel to lower slot209. The other side of this channel349then joins (orthogonally) to the top panel347which then joins exterior panel348that extends down and connects to the other end of the wall engaging portion341. The fixed window pane106only resides in the distal half of the window pane receiving channel, and thus the proximal half of the window pane receiving channel349is covered with a clipable panel344. This clips into a projection on the central arm345and ribs formed on the vertical edge adjacent the start of the top panel347.

FIGS. 9 and 10A-10Dillustrate the relative alignments of the various features of the window frame members. For example the inner panel325of the removable side frame member is aligned with the channel for the fixed glass pane349in the lower frame member, the pane receiving channel316of the first side frame member301, the lower clipable panel344(which forms part of the sill) and the upper clipable panel335. Similarly the interior panels313,322,332and342of the first and second side frame members and the upper and lower frame members (respectively) are all aligned (i.e. parallel). The hooked portions of the interior panels of the upper and lower frame members332and342are directed in the same direction and outward from the window frame (and in this context into the interior of the room). As shown inFIGS. 10C and 10Dthe projection322of the first side frame member, and the equivalent projection352on the second side frame member, extend into the interior to the same extent as the hooks.

The extrusions may be constructed of metals, including Aluminium, steel, and associated alloys, or other suitable materials such as plastics treated increase UV resistance or corrosions resistance. The window frame may be constructed in standard sizes, or be made to measure and shipped as a pre-assembled frame300to the building site. In this case, the installer installs the assembly into a cavity and seals the edges. The installer can then install the tension adjustment arrangement, or adjust the location as required. This can be performed by the installer partially unscrewing or removing fasteners264and265to allow the receiving block to at least partially disengage from the tapered edges267268, and thus allow the spring anchor's position within upper slot208to be adjusted. Once an appropriate location is selected (this may be a process of trial and error to find the location that enables smoothest opening and closing of the window), then the fasteners264and265are inserted or tightened to draw the receiving block towards tapered edges267268to generate the interference fit between the spring anchor216and the walls of the upper slot208. A similar procedure can be performed for the equivalent mechanism located in the lower slot (if present).

The slideable window panel107slides laterally within upper slot208and lower slot209. However, it will be noted that the operative members or cord211also run in the upper and lower slot. Accordingly, the path of the operative member is configured so that the frame does not impair movement of the operative member210or tension adjustment arrangement220. This can be achieved by fitting the window panel frame108with smooth feet or runner wheels extending both above and below the window panel frame to engage with the top of the upper slot208and the bottom of the lower slot209. Additionally, the width of the feet is less than the width of the idler pulley210so that they run within the two sections of cord. Additionally or alternatively, the upper slot208and209may be fitted with removable covers that house the house the operative member210or tension adjustment arrangement220, and upon which the feet or runner wheels move. In another embodiment, the window frame comprises a single pulley208, operative member and tension adjustment arrangement located in the upper slot. In this embodiment the lower mounting arrangement270simply provides a seat for receiving the base of the spindle207(or barrel250), and the window panel107runs along and is supported by the base of slot208. In this case, the window panel107does not extend fully into the upper slot208to provide headspace for the operative member and tension adjustment arrangement.

The above embodiments utilise an operative member in the form of a cord that is anchored at one end212to the post207or proximal end of the window panel at anchor point, and at the other end to the spindle pulley202. The operative member is looped around an idler pulley210. In the above embodiment, the idler pulley is part of a tension adjustment arrangement220that adjusts the location of the idler pulley210to compensate for changes in the tension of the operative member as the window is opened and closed. In another embodiment, the location of the idler pulley210is fixed and the tension adjustment arrangement is omitted. A further alternative embodiment is shown inFIGS. 11 and 12in which the cord211is replaced with a loop. As shown inFIG. 11, the cord211is secured at its first end212to the post207, is then located around the idler pulley210and is then wrapped around the pulleys202and203at least once before returning to be secured at its second end213to the post207. In this case, both opening and closing of the window panel107rotates the pulleys202and203. This arrangement requires a good grip between the cord211and the pulleys202and203in order to avoid any slippage. In order to prevent slippage a tooth belt218can be used instead of cord211, and a tooth pulley219can be secured to the spindle206. An embodiment of a tooth belt218and tooth pulley are illustrated inFIG. 12. In these embodiments the tension adjustment arrangement can be omitted.

Although the above embodiments shown in the Figures have a horizontally sliding window panel, the invention will be equally suited to window panels that slide vertically, such as in the case of sash windows. This is equivalent to rotating the frame ±90°, and thus the mechanism is the same, with the definition of side members and upper and lower frame members exchanged accordingly. In addition, in the above embodiments only one idler pulley210and roller assembly pulley202at either the top edge or the bottom edge of the window frame101may be utilised. Further, the invention would be equally suited to window frames that have a pair of moving window panels107located on each side of a large window frame100. Further, the system could be further adapted for use with two sliding windows that slide over each other rather than a fixed and sliding window arrangement. In this embodiment, each window would have its own cord and tension adjustment arrangement, and these would be vertically offset (i.e. vertically stacked) in order to prevent interference. Further, the window panes could instead be solid or opaque panels. It will also be understood that they system could also be used with sliding door arrangements. Other embodiments are also possible.

In other embodiments, the screen201or the post207maybe readily detachable from the window panel107so that the window panel107can be opened without the screen being in place. The screen201may be a mesh screen such as a fly screen, or it may be an opaque or semi-transparent air permeable material to provide a light block out function whilst permitting at least some air flow. Further, brush or felt strips maybe used in a conventional way to form a seal between the window panel107and the first pane of glass106. In addition, the slots208may be provided with brush or felt strips which act to from an air resistant seal at the edges of the screen201.

As will be seen from the above description the invention provides a novel means of moving the screen with respect to a moving panel. The advantage of the roller assembly200is that is does not require any form of spring based tensioning arrangements to rewind the screen201onto the roller assembly200. When the window panel107is closed, the screen201is fully retracted so that is does not obstruct the view to any extent when the window panel107is in its closed position.

The screen system described herein provides several advantages over existing screening systems. Notably the screen system uses a roller assembly comprising a screen wound onto a spindle. Thus, when the window is closed and the screen is not required the screen is hidden or integrated into the window frame. Further, the mechanism used for extending and retracting the screen does not require any form of spring based tensioning arrangements to rewind the screen onto the roller assembly. Instead, the arrangement guides an operative member around a pulley provided with a tension adjustment arrangement. This provides a smooth mechanism to extend and retract the screen. When the window panel is open and thus the screen is an extended position, closing the window is translated into a pulling action on the cord to unwind the cord off the first pulley, and this drives the rotation of the spindle to wind the screen back an. Conversely, opening the window to extend the screen rotates the spindle and pulley to wind the cord back onto the first pulley. Further, the roller assembly and guide assembly are relatively compact, allowing the frame to have a low thickness/profile. Additionally, the window frame members use clip in covers, and the roller assembly is designed to removably clip into the side frame member in which it is housed.

It will be appreciated by those skilled in the art that the invention is not restricted in its use to the particular application described. Neither is the present invention restricted in its preferred embodiment with regard to the particular elements and/or features described or depicted herein. It will be appreciated that the invention is not limited to the embodiment or embodiments disclosed, but is capable of numerous rearrangements, modifications and substitutions without departing from the scope of the invention as set forth and defined by the following claims.