[0001] The present invention relates to a closure for a door or window opening. The invention
               is concerned principally, although not exclusively, with an insect screen form of
               such closure.
 
            [0002] Conventionally, insect screens are mounted either to be lifted out bodily from the
               door or window, or, particularly in the case of doors, are mounted as hinged doors.
               As far as window insect screens are concerned, these are commonly made in a manner
               rather similar to roller blinds which can be retracted, e.g. by a spring loaded roller,
               or by a bead chain driven roller.
 
            [0003] US-A-1887646 shows such a insect proof screen which is primarily for a window or
               may be used, according to Figure 11 and 12 of that patent, as a door screen.
 
            [0004] It is an object of the present invention to provide improved and alternative structures
               to that disclosed in this document.
 
            [0005] It is now proposed, according to the invention, to provide a closure for a door or
               window opening, said closure comprising a rectangular frame having a rigid guide track
               on each of two opposite sides, a retractor roller mounted at a third side of the frame,
               a flexible screen wound at one of its ends on said retractor roller, a header bar
               secured to the other end of the flexible screen, said header bar having opposite ends
               that are being engaged and guided by said guide tracks for movement perpendicular
               thereto, a pair of wheels, one mounted at each end of the header bar, each wheel being
               operatively associated with means for synchronising the movement of opposite ends
               of the header bar to maintain movement of said header bar perpendicular to the guide
               tracks and brake means on said header bar effective simultaneously to stop rotation
               of both of said wheels and thereby to arrest movement of the header bar at any location
               along the length of said guide tracks.
 
            [0006] With such a structure it is possible to open the screen to any desired location and
               to lock the screen at that location along the length of the guide tracks. This can
               be advantageous particularly when it is used in combination with a sliding door arrangement
               which can be opened and adjusted for passage therethrough.
 
            [0007] While the closure is primarily intended to act as an insect screen, such that the
               material of the flexible screen is of a mesh type, it is contemplated that the flexible
               screen could be imperforate and opaque to provide a shutter like closure.
 
            [0008] The wheels may take various forms. For example, it could be simple wheels, e.g. with
               a rubber tyre on their periphery which runs on the guide track. An alternative possibility
               is having a wheel around which is wrapped a cord as disclosed, for example, in DE-A-3526745.
 
            [0009] However, according to a preferred construction, the wheels are each in the form of
               a toothed pinion and the guide tracks each have associated therewith a toothed rack,
               each rack being engaged by a separate one of said pinions. In order easily to mount
               the closure in a particular installation, the pinions are advantageously mounted in
               an adjustable bearings, permitting the teeth of the pinion to be disengaged from the
               teeth of the rack.
 
            [0010] While it is contemplated that the wheels could be braked separately, advantageously
               they are connected to a common shaft and the brake means acts on the common shaft.
               With such a structure, the brake means may comprise a laterally displaceable brake
               shoe, engageable with said common shaft, or a sleeve attached thereto, a wedge shaped
               actuating member carried by said header bar adjacent said brake shoe and a handle
               manually displaceable axially of said header bar, connected to said actuating member
               to cause the actuating member to move therewith and thereby cause the brake shoe to
               be urged against the common shaft or sleeve.
 
            [0011] It is contemplated that the wheels could each be connected to drive means adapted
               to rotate the wheels in a direction to move the header bar towards the closed position
               of the closure. Indeed, according to another aspect of the present invention, there
               is provided a closure for a door or window opening, said closure comprising a rectangular
               frame having a guide track on each of two opposite sides, a flexible screen attached
               at one of the ends at a third side of the frame and being retractable towards said
               third side, a header bar secured to the other end of the flexible screen, said header
               bar being guided by said guide tracks for movement perpendicular thereto, a pair of
               wheels one mounted at each end of the header bar, each wheel being operatively associated
               with one of said guide tracks, and drive means adapted to rotate the wheel in a direction
               to move said header bar towards a closed position of said closure.
 
            [0012] The drive means may comprise at least one torsion spring mounted in said header bar,
               said torsion spring being operatively connected to said wheels. While the wheels could
               be separately driven, they are desirably connected to a common drive shaft and said
               at least one torsion spring acts on the common drive shaft.
 
            [0013] The flexible screen may be attached at said one of its ends to a retractor roller,
               said retractor roller preferably includes at least one further torsion spring effective
               to cause the retractor roller to rotate to wind the screen in an opening direction
               into said retractor roller and said at least one torsion spring which is mounted on
               said header bar has a greater strength than that of said at least one further torsion
               spring on the retractor roller.
 
            [0014] Where the wheels are each in the form of a toothed pinion and the guide tracks each
               have associated therewith a toothed rack, each rack being engaged by a separate one
               of said pinions. Preferably as indicated above, the pinions are mounted on adjustable
               bearings, permitting the teeth of the pinions to disengage from the teeth of the rack,
               and further fixed teeth are provided and positioned to be engaged by the teeth of
               the pinions when they are disengaged from the teeth of the rack, to prevent rotation
               of the pinions. In this way the positioning of the teeth on the rack can be adjusted
               to suit a particular requirement despite the fact that there are drive means tending
               to rotate the pinions.
 
            [0015] Preferably the retractor roller is mounted for rotation in bearings associated with
               each of said two opposite sides, and a stepped annular shell is associated with each
               end of the retractor bar, and a fixed abutment is carried by the guide track to cooperate
               with individual steps of the confronting shell carried by the retractor roller, a
               coil compression spring urges said shell towards the fixed abutment, the steps on
               the two shells are inter-engaged with the associated fixed abutment and provide an
               adjustment of the axial length of the roller to suit a particular door or window opening.
 
            [0016] In order further to seal the door or window opening against the passage of insects,
               preferably the header bar has associated therewith an elongate brush projecting laterally
               away from the side of the header bar to which the screen is attached, this brush engaging
               the jamb of the door or window.
 
            [0017] In order further to ensure that the insect screen is sealed with reference to the
               guide tracks, the screen preferably has associated with its opposite edges, guide
               edges engageable with the guide tracks.
 
            [0018] In order that the present invention may more readily be understood, the following
               description is given, merely by way of example, reference being made to the accompanying
               drawings in which:-
               
               
Figure 1 is a perspective view of one embodiment of the closure of the invention shown
                  mounted as an insect screen covering a door opening;
               Figure 2 is a front elevation, partly in section, of the screen assembly shown in
                  Figure 1;
               Figure 3 is an enlarged fragmentary sectional view showing the mounting of the retractor
                  roller;
               Figure 4 is an enlarged fragmentary sectional view through the upper end part of the
                  header bar as viewed in the direction of the retraction roller of the closure showing
                  the pinion teeth engaged with the rack teeth;
               Figure 5 is a similar view to Figure 4 but showing the pinion teeth engaged with further
                  teeth on the header bar;
               Figure 6 is a detailed cross-sectional view through the header bar at the location
                  of the brake operating handle;
               Figure 7 is a view taken along the line VII-VII of Figure 6;
               Figures 8 and 9 are schematic side elevations and cross-sections through the header
                  bar illustrating the driving of the common shaft; and
               Figure 10 is a section through the header bar perpendicular to that of Figure 9 illustrating
                  the mounting of the lower end of the drive spring.
 
            [0019] Referring first to Figure 1, the screen 10, shown as an insect screen, is mounted
               to close a door opening in the form of a rectangular frame having an upper and a lower
               guide track 12,14 and a third side shown closed by a box 16. The left side of the
               screen 10 is secured to a vertical header bar 18 having upper and lower wheels (not
               shown in Figure 1) in the form of pinions which engage in racks 20,22 carried on the
               upper and lower tracks 12,14. The wheels are in fact carried by a common drive shaft
               and this can be braked by operation of a control handle 24 which is axially slidable
               on the header bar 18. The free side of the header bar 18 which is remote from the
               screen 10 is provided with a brush seal 26 to engage the jamb of the door opening
               when the screen is in the closed position.
 
            [0020] Mounted within the box 16 is a retractor roller 28 (Figure 2) to which the other
               edge of the screen 10 is attached. In order to tension the screen 10 a retractor torsion
               spring 30 is mounted within the roller 28, in a conventional manner and surrounds
               an upper support shaft 32. A similar lower support shaft 32 is provided at the bottom.
 
            [0021] At each end of the support shaft there is provided a bearing arrangement indicated
               by the general reference 34. and illustrated in more detail in Figure 3. Connected
               to the upper track 12 is a housing member 36, having a generally cylindrically shaped
               housing portion 38 in which is rotatably mounted a bearing member 40, having an upper
               stepped shell 42, provided with two ramp-like stepped surfaces 44, displaced 180°
               from one another. A fixed abutment 46 is provided on each of two diametrically opposite
               sides of the interior of the housing portion 38 and projects downwardly. The bearing
               member is urged axially upwardly by a coil compression spring 48 (shown in a compressed
               state) and is keyed to the shaft 32 for axial sliding movement relative thereto.
 
            [0022] In use the housing member 36 is secured to the rail and in order to allow for the
               variation in the spacing between the upper and lower tracks to suit the minute details
               of a particular doorway, the rotational position of the shell 42 is chosen so that
               its appropriate steps 44 engage the abutments 46 to hold the shell firmly against
               any further rotation. It is contemplated that instead of having an abutment 46 a second
               similar shell 42 could be provided and in this instance it would be advantageous for
               the steps to be undercut so that they engage fully.
 
            [0023] It will be seen that surrounding the lower part of the upper shaft 32 is a torsion
               spring engaging member 50, also shown in Figure 2, this engaging the end of the torsion
               spring 30. If reference is still made to Figure 2 it will be seen that a pip 52 is
               provided to the upper and lower ends of the screen 10 at one or more spaced intervals
               along the edges of the screen to act as guides for the screen on the tracks 12,14.
 
            [0024] As mentioned earlier, the header bar 18 has at its upper and lower ends a wheel,
               and in the embodiment illustrated this wheel is in the form of a pinion 54 having
               peripheral teeth 56 (Figures 4 and 5). In Figure 4 the teeth are shown engaged with
               the teeth 58 of the upper rack 20. A similar assembly is, of course, provided at the
               bottom. The pinion 54 is mounted for rotation in an eccentric bearing 60 mounted in
               an upper cap part 62 of the header bar. The eccentric bearing 60 may be rotated so
               that the pinion 54 is moved out of engagement with the teeth 58 and into engagement
               with further teeth 64 on the cap 62 as shown in Figure 5. These further teeth 64 prevent
               the pinion 54 from rotating, while not engaged with the rack 20.
 
            [0025] Associated with the cap 62 is a projection 66 which engages within the upper track
               12 to guide the end of the header bar along the track. Because there are toothed pinions
               provided at each end, the guiding of the header bar is such as to ensure that the
               axis of the header bar 18 is always vertical, that is perpendicular to the direction
               of the tracks 12,14.
 
            [0026] If reference is now made to Figures 6 and 7, it can be seen that the header bar 18
               has a part tubular cross-section portion 68, and a recessed rear portion 70. Within
               the part tubular portion is mounted a common shaft 72 which carries the upper and
               lower wheels (pinions 54). This is a splined shaft on which is mounted a brake drum
               sleeve 74 which may optionally be engaged by a brake shoe 76 having a wedge like rear
               face 78. The operating handle 24 has a hollow body 79 which encompasses the part tubular
               portion 68 of the header bar and has a key portion 80 which extends through a rectangular
               aperture 82 in the header bar 18.
 
            [0027] Mounted within the recess 70 is a rear operating member 84 which is located in the
               recess 70 and is engaged by the key 80 so that the front operating handle 24 and the
               rear operating member 84 can be caused to move longitudinally of the holding bar 18
               together.
 
            [0028] Facing the wedge like ramp 78 of the brake shoe 76 is a complementary ramp surfaces
               86. Thus, upon operation in an upward direction of the front operating member 24 (or
               the rear operating member 24) the two ramp surfaces 78,86 are more fully engaged thereby
               to urge the brake shoe 76 against the brake sleeve 74. As illustrated in Figure 7,
               this in fact urges the brake drum 74, and with it the common shaft 72, to the right.
               A displacement d is thus brought about and the resilience of the common shaft 72 is
               used to assist in this braking action.
 
            [0029] If reference is made to Figures 8, 9 and 10, it can be seen that a portion of the
               common shaft 72 is surrounded by an upper drive housing 88, around which is disposed
               a torsion drive spring 90, the drive housing being engaged by the drive spring 90
               through engagement in one of the splines 75 (Figure 6) therein, a retainer spring
               92 holding the drive housing 88 in place. A projection 94 on a lower spring housing
               96 engages in the opening 69 of the part tubular portion 68, to prevent the lower
               housing 96 from rotating to provide the reaction force for the spring 90. The spring
               90 is wound in a direction to cause the common shaft 72 and therefore the pinions
               54 to rotate in a direction to close the screen. The force produced by the drive spring
               90 is greater than that produced by the recoil spring 30, which is simply used to
               take up slack in the screen when the header bar is moved towards the opening position.
               By operation of the handle 24, or the rear operating member 84, the screen can be
               locked anywhere along the length of the tracks 12,14. In this manner the header bar
               can simply be moved against the jamb of a sliding door which is in a partly opened
               position and the bar can be locked on its own. In this circumstance the screen could
               move in a track parallel to and adjacent the sliding door and the angled brush 26
               is used to block the passage for insects.
 
          
         
            
            1. A closure for a door or window opening, said closure comprising a rectangular frame
               having a rigid guide track on each of two opposite sides, a retractor roller mounted
               at a third side of the frame, a flexible screen wound at one of its ends on said retractor
               roller, a header bar secured to the other end of the flexible screen, said header
               bar having opposite ends that are being engaged and guided by said guide tracks for
               movement perpendicular thereto, a pair of wheels, one mounted at each end of the header
               bar, each wheel being operatively associated with means for synchronising the movement
               of opposite ends of the header bar to maintain movement of said header bar perpendicular
               to the guide tracks and brake means on said header bar effective simultaneously to
               stop rotation of both of said wheels and thereby to arrest movement of the header
               bar at any location along the length of said guide tracks.
 
            2. A closure according to claim 1, wherein the wheels are each in the form of a toothed
               pinion and wherein the guide tracks each have associated therewith a toothed rack,
               each rack being engaged by a separate one of said pinions.
 
            3. A closure according to claim 2, wherein the pinions are mounted on adjustable bearings,
               permitting the teeth of the pinions to be disengaged from the teeth of the rack.
 
            4. A closure according to any preceding claim, wherein both of the wheels are connected
               to a common shaft and wherein said brake means acts on the common shaft.
 
            5. A closure according to claim 4, wherein said brake means comprise a laterally displaceable
               brake shoe, engageable with said common shaft, or a sleeve attached thereto, a wedge
               shaped actuating member carried by said header bar adjacent said brake shoe and a
               handle manually displaceable axially of said header bar, connected to said actuating
               member to cause the actuating member to move therewith and thereby cause the brake
               shoe to be urged against the common shaft or sleeve.
 
            6. A closure according to any preceding claim, wherein the wheels are each connected
               to drive means adapted to rotate the wheels in a direction to move said header bar
               towards the closed position of said closure.
 
            7. A closure for a door or window opening, said closure comprising a rectangular frame
               having a guide track on each of two opposite sides, a flexible screen attached at
               one of the ends at a third side of the frame and being retractable towards said third
               side, a header bar secured to the other end of the flexible screen, said header bar
               being guided by said guide tracks for movement perpendicular thereto, a pair of wheels
               one mounted at each end of the header bar, each wheel being operatively associated
               with one of said guide tracks, and drive means adapted to rotate the wheels of said
               pair in a direction to move said header bar towards a closed position of said closure.
 
            8. A closure according to claim 6 or 7, wherein the drive means comprise at least one
               torsion spring mounted in said header bar, said torsion spring being operatively connected
               to said wheels.
 
            9. A closure according to claim 8, wherein both of the wheels are connected to a common
               drive shaft and wherein said at least one torsion spring acts on the common shaft.
 
            10. A closure according to claim 7, 8 or 9, wherein brake means are provided on said header
               bar effective simultaneously to stop rotation of both of said wheels and thereby to
               arrest movement of the header bar at any location along the length of said guide tracks.
 
            11. A closure according to claim 8, 9 or 10, wherein the flexible screen is attached at
               said one of its ends to a retractor roller, and wherein said retractor roller includes
               at least one further torsion spring effective to cause said retractor roller to rotate
               to wind the screen in an opening direction onto said retractor roller, and wherein
               said at least one torsion spring mounted on said header bar has, a greater strength
               than that of said at least one further torsion spring on the retractor roller.
 
            12. A closure according to any one of claims 6 to 11, wherein the wheels are each in the
               form of a toothed pinion and wherein the guide tracks each have associated therewith
               a toothed rack, each rack being engaged by a separate one of said pinions, on adjustable
               bearings permitting the teeth of the pinions to be disengaged from the teeth of the
               rack and wherein further fixed teeth are provided and positioned to be engaged by
               the teeth of the pinions, when they are disengaged from the teeth of the rack, to
               prevent rotation of the pinions.
 
            13. A closure according to any preceding claim, wherein the retractor roller is mounted
               for rotation in bearings associated with each of said two opposite sides, and wherein
               a stepped annular shell is associated with each end of the retractor bar, and a fixed
               abutment is carried by the guide track to cooperate with individual steps of the confronting
               shell carried by the retractor roller, a compression spring urges said shell towards
               the fixed abutment, the steps on the two shells are inter-engaged with the associated
               fixed abutment and provide an adjustment of the axial length of the roller to suit
               a particular door or window opening.
 
            14. A closure according to any preceding claim, wherein the header bar has associated
               therewith an elongate brush projecting laterally away from the side of the header
               bar to which the screen is attached.
 
            15. A closure according to any preceding claim, wherein the screen has associated with
               its opposite edges guide elements engageable in the guide tracks.
 
            16. A closure according to any preceding claim, wherein the screen is in the form of an
               insect screen.
 
            17. An insect screen for a door or window opening, substantially as hereinbefore described
               with reference to and as illustrated in the accompanying drawings.