Pull across roll up screen assembly

Abstract

A pull across screen assembly has a flexible screen member (e.g. flymesh) wound about a vertical rod positioned at one side of the opening. A line member arrangement is attached to the front of the screen member and part of the line member winds about a tapered drum which is positioned on top of rod and which rotates with rotation of the rod. The arrangement allows the screen member to be tensioned and also to be balanced as it is pulled across the opening.

Claims

1. A screen assembly comprising: a substantially vertical flexible screen having a front edge area, a supporting member about which the screen can be wound/unwound and which is substantially vertical and has an upper end and a lower end, a biasing means associated with the supporting member to create a tension in the screen to bias the supporting member to a wound condition, a single drum/pulley supported upon at least one end of the supporting member, the single drum/pulley is configured as a cone and comprising a first end and a peripheral circumference that tapers diametrically from the first end to a smaller second end, the smaller second end more proximate the screen and the cone configuration being aligned vertically with the supporting member along the second end to the first end of the single drum/pulley, a line member that can be wound onto and off the single drum/pulley, the line member being operatively associated with the screen such that as the screen is extended, the line member is wound onto the single drum/pulley, and as the screen is retracted, the line member is wound off the single drum/pulley, the screen, when wound about the supporting member, having a diameter which increases as the screen material is wound about supporting member, and which decreases as the screen material is unwound from the supporting member, the diameter of the single drum/pulley, at the position where the line member winds onto the single drum/pulley or off the single drum/pulley, being about the same diameter of the supporting member containing the screen, the line member being operatively attached to the front edge area of the screen, the line member comprises: a first part which winds onto and off the single drum/pulley, a second part which is attached to the first part via a joiner block, the second part being operatively connected to an upper front edge area of the screen, and a third part which is attached to the first part via the joiner block, the third part being operatively connected to a lower front edge area of the screen, the joiner block mounting the second part and the third part to the first part; at least one return pulley for guiding the second part and the third part around the at least one return pulley; and wherein the line member is configured such that the joiner block moves in an opposite direction to the direction of movement of the front edge area of the flexible screen, and a pair of balancing biasing means to create a balanced tension in the substantially vertical screen, a first balancing biasing means mounted to the front edge area of the screen at a first mounting point and attached to the second part of the line and a second balancing biasing means mounted to the front edge area of the screen at a second mounting point and attached to the third part of the line, the pair of biasing means independent of one another.

2. The assembly of claim 1, wherein the biasing means to create a tension in the screen is operatively attached to the front edge area of the screen, and the line member is operatively attached to the biasing means.

3. The assembly of claim 1 wherein the line member is configured to be wound over the drum/pulley from proximate the smaller second end toward the larger first end during the unwinding of the screen from over the supporting member.

4. The assembly of claim 1 wherein the drum/pulley comprises a peripheral circumference and a groove spiraling around the peripheral circumference, the groove configured to receive portions of the line member.

5. The assembly of claim 1 wherein the line member comprises a single line only that is wound and unwound over the drum/pulley during the selective unwinding and winding of the screen.

6. The assembly of claim 1 wherein the line member comprises: a single line structure; a double line structure; and wherein the joiner block connects the single line structure to the double line structure.

7. The assembly of claim 1 wherein the front edge area of the flexible screen comprises a top portion opposite a bottom portion, the top portion comprising a first pulley and the bottom portion comprising a second pulley, and further comprising: a first return pulley laterally spaced from the drum/pulley, the first return pulley having the radially outer guide and the radially inner guide; a second return pulley diagonally spaced from the drum/pulley; and wherein the line member is operatively secured over the first return pulley and the second return pulley.

8. The assembly of claim 1, comprising a stile attached to the front edge area of the screen.

9. The assembly of claim 8, wherein the biasing means to create a tension in the screen is attached to the stile.

10. The assembly of claim 9, wherein the biasing means comprises at least one spring, one end of which is attached to the stile, and the other end of which is attached to the line member.

11. The assembly of claim 10, the at least one spring comprising: a first spring attached to the second part of the line member in an upper part of the stile, and a lower spring attached to the third part of the line member in a lower part of the stile.

12. The assembly of claim 11, wherein the biasing means is attached to the line member which is operatively attached to the upper edge area of the screen, and to the line member which is attached to the lower edge area of the screen.

13. The assembly of claim 11, wherein only the single drum/pulley is provided.

14. The assembly of claim 1 wherein the joiner block is located between the drum/pulley and a first return pulley.

15. The assembly of claim 14 wherein the second and third line members only are operatively secured over the first return pulley.

16. The assembly of claim 15 wherein the first line member only is operatively secured over a first return pulley.

17. The assembly of claim 16 wherein the drum/pulley is located on the upper end of the supporting member, and the first return pulley is located adjacent an upper end of an opposed end of a cavity in which the assembly is located to the drum/pulley.

18. The assembly of claim 17 wherein the assembly further comprises a second return pulley located adjacent a front edge of the screen, a third return pulley located adjacent a lower end of the opposed end of the cavity in which the assembly is located to the drum/pulley, and a fourth return pulley adjacent the front edge of the screen.

19. The assembly of claim 18 wherein the second line member is operatively secured over the second return pulley, and the third line member is operatively secured over the third return pulley and the fourth return pulley.

20. A screen assembly comprising: a flexible screen having a front edge area, a supporting member about which the screen can be wound/unwound and which is substantially vertical and has an upper end and a lower end, a biasing means associated with the supporting member to create a tension in the screen to bias the supporting member to a wound condition, a single drum/pulley only and on the upper end of the supporting member, the single drum/pulley is configured as a cone and comprising a first end and a peripheral circumference that tapers diametrically from the first end to a smaller second end, the smaller second end more proximate the screen and the cone configuration being aligned vertically with the supporting member from the second end to the first end of the single drum/pulley, a line member that can be wound onto and off the single drum/pulley, the line member being operatively associated with the screen such that as the screen is extended, the line member is wound onto the single drum/pulley, and as the screen is retracted, the line member is wound off the single drum/pulley, the screen, when wound about the supporting member, having a diameter which increases as the screen material is wound about supporting member, and which decreases as the screen material is unwound from the supporting member, the line member comprising: a first part which winds onto and off the single drum/pulley, a second part which is attached to the first part via a joiner block, the second part being operatively connected to an upper front edge area of the flexible screen, and a third part which is attached to the first part via the joiner block, the third part being operatively connected to a lower front edge area of the flexible screen, the diameter of the single drum/pulley, at the position where the line member winds onto the single drum/pulley or off the single drum/pulley, being about the same diameter of the supporting member containing the screen, the line member being operatively attached to the front edge area of the screen, a joiner block for combining two portions of the line member, the line member is configured such that the joiner block moves in an opposite direction to the direction of movement of the front edge area of the flexible screen, the joiner block for mounting the second part and the third part to the first part, and at least one return pulley for guiding the second part and the third part around the at least one return pulley; and a pair of balancing biasing means to create a balanced tension in the substantially vertical screen, a first balancing biasing means mounted to the front edge area of the screen at a first mounting point and attached to the second part of the line and a second balancing biasing means mounted to the front edge area of the screen at a second mounting point and attached to the third part of the line, the pair of biasing means independent of one another so that together, the pair of balancing biasing means balances the tension in the screen.

21. The assembly of claim 20, wherein the biasing means to create a tension in the screen is operatively attached to the front edge area of the screen, and the line member is operatively attached to the biasing means.

22. The assembly of claim 20 wherein the drum/pulley comprises a peripheral circumference and a groove spiraling around the peripheral circumference, the groove configured to receive portions of the line member.

23. The assembly of claim 20, wherein the front edge area of the flexible screen comprises a top portion opposite a bottom portion, and top portion comprising a first pulley and the bottom portion comprising a second pulley, and further comprising: a first return pulley laterally spaced from the drum/pulley, the first return pulley having the radially outer guide and the radially inner guide; a second return pulley diagonally spaced from the drum/pulley; and wherein the line member is operatively secured over the first return pulley and the second return pulley.

24. The assembly of claim 20, comprising a stile attached to the front edge area of the screen.

25. The assembly of claim 24, wherein the biasing means to create a tension in the screen is attached to the stile.

26. The assembly of claim 25, wherein the biasing means comprises a spring, one end of which is attached to the stile, and the other end of which is attached to the line member.

27. The assembly of claim 26, comprising a first spring attached to the second part of the line member in an upper part of the stile, and a lower spring attached to the third part of the line member in a lower part of the stile.

28. The assembly of claim 1 or 20, further comprising an adjustment assembly to adjust the angle of the supporting member.

29. The assembly of claim 28, wherein the adjustment assembly is a screw adjustable mechanism wherein the assembled unit of drum and supporting member are attached to a block member via a pin or bearing member to enable rotation of the drum and supporting member and which has at one position a tapped hole into which is engaged a threaded member, a part of which is engaged into a secondary block member which is in turn fixed to a door frame rotation of the threaded member causing the threaded portion to induce linear movement of the block member along an axis of the threaded member thereby enabling the supporting member to be adjusted to a substantially vertical position.

30. The assembly of claim 28, wherein the biasing means to create a tension in the screen is operatively attached to the front edge area of the screen, and the line member is operatively attached to the biasing means.

31. The assembly of claim 28, wherein only a single drum/pulley is provided.

32. The assembly of claim 28, comprising a stile attached to the front edge area of the screen.

33. The assembly of claim 32, wherein the biasing means to create a tension in the screen is attached to the stile.

34. The assembly of claim 33, wherein the biasing means comprises a spring, one end of which is attached to the stile, and the other end of which is attached to the line member.

35. A screen assembly comprising: a supporting member extending vertically; a flexible screen having a front edge area, the flexible screen being secured to the supporting member in a configuration to allow the screen to be selectively wound and unwound over the supporting member; a drum configured as a cone, the cone comprising a first end and a peripheral circumference that tapers diametrically from the first end to a smaller second end, the drum is secured to the supporting member with the smaller second end more proximate the screen and the cone configuration being aligned vertically with the supporting member from the second end to the first end of the drum, the drum being the only drum secured to the supporting member; and a line member operatively secured between the drum and the screen in a configuration that allows the line member to be wound and unwound over the drum during the selective unwinding and winding of the screen, the line member comprising: a first part which winds onto and off the drum, a second part which is attached to the first part via a joiner block, the second part being operatively connected to an upper front edge area of the flexible screen, and a third part which is attached to the first part via the joiner block, the third part being operatively connected to a lower front edge area of the flexible screen; a joiner block for combining the second and third parts of the line member, the line member being configured such that the joiner block moves in an opposite direction to the direction of movement of the front edge area of the flexible screen, the joiner block mounting the second part spaced apart and parallel from the third part, and at least one return pulley having a radially outer guide for the third part and a radially inner guide for the second part to maintain the second part spaced apart, and parallel to, the third part around the at least one return pulley.

36. The assembly of claim 35 wherein the drum comprises a groove spiraling around the peripheral circumference of the drum, the groove configured to receive portions of the line member.

37. The assembly of claim 35 wherein the line member is configured to be wound over the drum from proximate the smaller second end toward the larger first end during the unwinding of the screen from over the supporting member.

38. The assembly of claim 35, wherein the front edge area of the flexible screen comprises a top portion opposite a bottom portion, the top portion comprising a first pulley and the bottom portion comprising a second pulley, and further comprising: a first return pulley laterally spaced from the drum, the first return pulley having the radially outer guide and the radially inner guide; a second return pulley diagonally spaced from the drum; and wherein the line member is operatively secured over the first return pulley and the second return pulley.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Embodiments of the invention, will be described with reference to the following drawings in which:

(2) FIG. 1. Illustrates an upper portion of the screen assembly particularly illustrating the drum and the screen fully extended.

(3) FIG. 2. Illustrates the view of FIG. 1, with the screen partially extended.

(4) FIG. 3. Illustrates a lower portion of the front edge of the screen and particularly illustrating the third pulley, the fourth pulley and the lower end of the biasing means (the housing being removed on the front edge of the screen for clarity).

(5) FIG. 4. Illustrates an upper portion of the front edge of the screen and particularly illustrating the first return pulley and a second pulley and an upper part of the biasing means which is adjacent the front edge of the screen.

(6) FIG. 5. Illustrates the screen in the retracted position.

(7) FIG. 6. Illustrates the screen in the approximately half extended position.

(8) FIG. 7. Illustrates schematically a screen assembly containing a line member, pulleys, springs etc.

(9) FIG. 8. Illustrates schematically a double screen assembly.

(10) FIG. 9. Illustrates schematically an embodiment of the invention using a counterweight.

(11) FIG. 10. Illustrates schematically an embodiment of the invention showing a different arrangement of springs.

(12) FIG. 11. Illustrates schematically an embodiment of the invention using a single spring.

(13) FIG. 12. Illustrates schematically an embodiment similar to that described with reference to FIG. 11 but showing a different pulley arrangement adjacent the single spring.

(14) FIG. 13. Illustrates schematically an embodiment similar to that described with reference to FIG. 7 but showing a different positioning of the line member.

(15) FIG. 14. Illustrates schematically an embodiment similar to that described with reference to FIG. 7 but showing the spring in a different position.

(16) FIG. 15. Illustrates schematically a double unit according to another embodiment.

(17) FIG. 16. Illustrates schematically a double unit according to another embodiment of the invention and illustrating the use of a pair of drums on each unit.

(18) FIG. 17. Illustrates schematically an assembly similar to that described with reference to FIG. 7 but showing an upper and lower drum arrangement.

(19) FIG. 18. Illustrates schematically an assembly similar to that described with reference to FIG. 7, but illustrating an offset upper drum.

(20) FIG. 19. Illustrates schematically an assembly similar to that described with reference to FIG. 7, but showing the use of a operating member to operate the line member but where the line member is not wound about the operating member.

(21) FIG. 20. Illustrates schematically a motorised unit and showing the different positions where the motor could be positioned.

(22) FIG. 21. Illustrates schematically a preferred drum.

(23) FIG. 22. Illustrates schematically a drum which is cylindrical.

(24) FIG. 23. Illustrates schematically a drum having a stepped cylindrical profile.

(25) FIG. 24. Illustrates schematically a drum having a tapered cone at either end with a parallel portion in the centre.

(26) FIG. 25. Illustrates schematically a drum in the shape of a reverse barrel.

(27) FIGS. 26-30. Illustrate, inter alia, lateral adjustment of the assembly.

(28) FIG. 31. Illustrates the use of a spring inside the fabric supporting rod.

(29) FIG. 32. Illustrates a variation to FIG. 31.

(30) FIG. 33. Illustrates another embodiment of the invention.

(31) FIG. 34. Illustrates operation of the mechanism.

(32) FIG. 35. Illustrates operation of the mechanism.

BEST MODE

(33) In the various embodiments, If the same reference numeral identifies different parts in the different embodiments, that reference numeral refers only to the part in the particular embodiment.

(34) Referring to FIGS. 1-6, the screen assembly according to the particular embodiment basically comprises the following components:A screen 10, which in the particular embodiment comprises an insect screen, a supporting member 11 about which the screen is wound and unwound, a drum 12 which is positioned in an upper part of the assembly and on top of supporting member 11, a front edge 13 of the screen 10 and which is made of an elongate aluminium section, a biasing means 14 (the lower portion being visible in FIG. 3, and the upper portion being visible in FIG. 4), the biasing means being attached to front edge 13, a line member which is split into a first line member 15 and a second line member 16 (this will be described in greater detail below), a first return pulley 17 (FIG. 4), a second pulley 18 (FIG. 4), a third return pulley 19 (FIG. 3) and a fourth pulley 20 (FIG. 3).

(35) There are many advantages to this arrangement. One advantage is that the screen can be balanced at a plurality of positions (and indeed it may be balanced substantially continuously) as the screen is extended and retracted. Another advantage in the particular embodiment is that the biasing means (in this case springs) is not positioned in the supporting member, but instead can be positioned within or next to the front edge 13.

(36) Screen 10, and the particular embodiment, can be extended between 2-5 m and therefore has this length at least. One end of the screen 10 is attached to the supporting member 11. Supporting member 11 is mounted for rotation about its longitudinal axis such that the screen 10 can be wound and unwound from the supporting member. Importantly, as screen 10 is wound or unwound from the supporting member, the diameter (this being the diameter of the supporting member+any attached screen material) will vary, and will decrease as the screen is unwound and will increase as the screen is wound.

(37) Attached to the top of supporting member 11 is drum 12. In the particular embodiment, drum 12 has a tapered face and is therefore substantially conical. The taper goes from a smaller diameter adjacent the top of the supporting member 11 to a large diameter. It is envisaged that the drum may also be positioned the other way as well. The length of the drum is approximately 3 cm. The widest part of the drum (in the particular embodiment) will be approximately the same diameter as the widest diameter of the supporting member 11+screen 10 (that is when the screen is fully wound on the drum and is completely retracted), and the narrowest part of the drum (in the particular embodiment) will be approximately the same diameter of the diameter of the supporting member+any remaining screen 10 when the screen has been fully extended, and unwound from the drum.

(38) The first line member 15, which in the particular embodiment comprises a plastic coated steel wire having a diameter of between 1-3 mm, has one end attached to the drum. Therefore, rotation of the drum will cause line member 15 to wind on to the drum or off the drum as the case may be. In the particular embodiment, and because of the cone shape of the drum, the line member will be laid next to each other on the drum. Thus, the diameter of the drum at the point where the line member is wound onto or off the drum will vary because of the conical shape of the drum.

(39) The first line member 15 extends from drum 12 and extends about first return pulley 17 and then about second pulley 18 and is ultimately attached to the upper part of the biasing means 14 which in the particular embodiment comprises a spring. Thus, there is tension in the first line member 15. A second line member 16 is also provided which is formed from the same material as first line member and second line member 16 has one end which is joined to first line member (and therefore branches therefrom) in between drum 12 and first return pulley 17. Second line member 16 then also extends about first return pulley 17 but then extends substantially vertically to extend about third pulley 19, then fourth pulley 20 and is attached to the lower end of biasing means 14. Thus, there is tension in second line member 16.

(40) The biasing means 14, and second pulley 18 and third pulley 19 are all attached to or relative to the front edge 13 of the screen and therefore move with the screen.

(41) In use, as the screen is extended, the first line member will be wound about and onto drum 12. In the particular embodiment, as the line winds onto the drum the line progressively winds from the larger diameter of the drum to the narrower diameter of the drum and therefore the diameter reduces where the line is wound onto the drum. This can be seen with reference to FIG. 1 and FIG. 2. At the same time, the diameter of the support member 11 containing the wound up screen material 10 will decrease as the screen material is unwound, and the construction and arrangement is such that the diameter of the drum is about the same at any one point as the diameter of the support member+any remaining screen material. This will also be the case when the screen is retracted as this will cause the diameter of the support member+screen material to increase and at the same time the line member is being unwound from the drum at progressively increasing diameters.

(42) It is found that this assists in allowing for balancing tension to be applied at all time. The drum enables a constant length of screen to be on a roll (supporting member) at all times thereby largely eliminating the need to allow for a change in length deployed in the system. The use of a spring as opposed to counterweights can reduce the system inertia.

(43) Further embodiments of the invention or further clarification of existing embodiments of the invention is given below:

(44) FIG. 7

(45) Preferred Embodiment of Single Unit.

(46) A line member is attached to a biasing member (e.g. a tension spring) contained in either end of the moveable vertical stile, in this embodiment, line member 5a is attached to biasing member (3a), and line member (5b) is attached to biasing member (3b). The pretension force applied by each extended biasing member (Force A from the top member and Force B from the bottom member) is transferred to the respective line members (5a and 5b), which are taken around pulleys (7) at one end of the aperture to be screened. Each pulley (7) includes a pair of guides, each guide for guiding line members 5a and 5b. The guides maintain the line members (5a and 5b) spaced apart and parallel to one another around the pulley (7). The two line members (5a and 5b) are attached to a joiner block (4) and a third line member (5) (or alternatively either 5a or 5b could extend through the joiner block (4)) is attached to the other side of the joiner block. The joiner block mounts the two line members (5a and 5b) spaced apart and parallel from one another. Force C in line member 5 is equal to the combined forces A&B and the other end of this line member 5 is attached to a drum or spooling member which is fixed to the top end of a rod (6) onto which the flexible membrane (2) is rolled.

(47) As the stile (3) is moved away from the rod (6), the flexible membrane is unrolled from the rod (6) and at the same time the line member (5) is wound onto the drum (1). The tension (Force C) in the line member (5) is applied to the drum (1) causing a resultant torque. In a perfectly balanced system, if the effective diameter of drum (1) is equal to the outer diameter of the roll of flexible membrane (2) on the rod (6), then the torque applied by the line member is perfectly balanced by the torque applied by the distributed net force in the flexible membrane (2) and there is no tendency for the system to move in any direction except by the application of an external force applied somewhere in the system (either by a persons hand or foot or by electrically powered device). In this situation, the resultant Force C in the line member (5) is equal to the force (tension) in the flexible fabric (2). In the absence of any external force being applied to the system, friction will overcome the low inertia of the system and the stile member (8) will stop moving smoothly after being released.

(48) If the diameters of the drum on which the line member is wound, or the diameter of the roll of the flexible membrane are not matched, then a resultant torque is applied to the rod member (6) and then the system will be biased to move in one direction by the release of the potential energy stored in biasing means (3) and the unit will tend to move in one directioneither rolling up onto the rod (6) or further deploying across the aperture towards the pulleys (7) around which the line members 5a and 5b pass. The direction of movement is determined by the relative diameters. If the effective diameter of the drum is the lesser, then the line member (5) will tend to wind onto it, but if the roll diameter on the rod (6) is lesser, then the flexible fabric will tend to roll onto the rod.

(49) FIG. 8.

(50) Preferred Embodiment of a Double Unit

(51) This is simply a combination of a unit as shown in FIG. 7 and a mirror image of the same unit. Such a double unit can be used to cover an opening (or aperture or space) twice as wide as can be covered by a single unit. The opposing vertical stile members (8) can meet at any point where they can latch together by any meanssuch as the use of magnetic strips or mechanical latching devices.

(52) FIG. 9.

(53) The preferred biasing means from FIG. 7 (tension springs) which were used to impart a tension in the system have been replaced by hanging weights. This system will work effectively, but will be constrained because the maximum deployment width of the flexible membrane (2) is equal to or less than the overall height of the unit in most practical situations. Only if the weights are allowed to fall below the bottom of the aperture can a greater width of operation be achieved. An additional shortcoming may be that the mass of the suspended weights must be accelerated when initiating or stopping the vertical stile member (8). The forces can still be in equilibrium in a balanced system.

(54) FIG. 10.

(55) One of the springs from the preferred embodiment has been moved from the moveable vertical stile member to a different (static) location.

(56) FIG. 11.

(57) One spring is used instead of two as shown in the preferred embodiment. This system will work effectively, but the ability to apply differential tensions at the top and bottom of the moveable vertical stile member (8) is now lost, and the entire system is tensioned at one time. An additional variation on this means would have the center point of the biasing member (3) fixed to the vertical stile (4) which would in effect allow the two ends to act independently of each other.

(58) FIG. 12.

(59) Similar in principle to FIG. 11 except that a pulley (9) is attached to either end of the biasing member (3) inside vertical stile member (8). This has the effect of halving the travel of the biasing member (3) to compensate for any system imbalance, but requires additional components and room for them to be housed in the vertical stile member (8).

(60) FIG. 13.

(61) Similar to the unit in FIG. 7 except that the line member 5b is returned up through the vertical member (8). This configuration would be useful where an opposing jamb was not able to be used to hide the cable in.

(62) FIG. 14.

(63) Similar to the unit in FIG. 7 except that the biasing means has been moved to the opposing jamb instead of being contained inside the moveable vertical stile member (8). The biasing means (3) is in this instance shown as a single device with a pulley at either end as described in FIG. 12.

(64) FIG. 15.

(65) Similar to the preferred embodiment of a double unit (refer FIG. 8.) (5a) returns around a pulley (9) mounted atop the drum (1) instead of pulley (7) located adjacent to the drum. This embodiment has the advantage of keeping line member (5a) as high as possible avoiding possible problems with crossover with other cables, but has the disadvantage of adding additional height to the unit above the top line of the flexible membrane.

(66) FIG. 16.

(67) Similar to the preferred embodiment of a double unit (refer FIG. 8) except that the joiner block (4a) is attached to the top end of the opposing vertical stile member (8b). The effect of this is to force the 2 vertical stile members (8a and 8b) to work in unison, such that moving stile 4a to the right causes stile 4b to move an equal distance to the leftand vice versa.

(68) FIG. 17.

(69) Similar to the preferred embodiment (FIG. 7) of a single unit, except that there is a drum at both the top and bottom of the rod member (6) onto which the flexible membrane is rolled. The top line member (5a) is wound onto the top drum and the bottom line member (5b) is wound onto the bottom drum. This embodiment has the advantages of not having to join cables together and not having to take the cable up the opposing end of the aperture. A disadvantage of this method is that a drum must be located at or below the bottom of the flexible membranewhich is generally a dirty area and one where additional room particularly if it increases overall height) is very scarce. The arrangement of FIG. 17 will usually not form part of the present invention.

(70) FIG. 18.

(71) Similar to the preferred embodiment (FIG. 7) of a single unit except that the drum member has been moved away from the preferred location on top of the vertical rod member (6) to some other location. The drum unit (1) is mechanically connected to the rod member (6) by gears, a chain, belt or some other drive means which induce the drum to turn whenever the rod member turns due to movement of the vertical stile member (8). It is also possible to drive the drum mechanism via the line member in a similar configuration. Being able to accumulate the line member in a location removed from the immediate area of the rod member 6 may allow for better utilization of space.

(72) FIG. 19.

(73) Similar to the preferred embodiment (FIG. 7) except that instead of the line member (5) being wound onto a drum (which is somewhat bulky), the line member could pass through a mechanism on top of (or somehow connected to) the rod member 6 which controls the rate of feed of the line member. Use of a line member made from ball chain (balls attached to a cord) would provide an easy means for controlling such feedthe ball chain could pass through a sprocket arrangement that ensured positive feed in either direction. The line member would be in tension on one side of the sprocket, but would not need to be after exiting the sprocket (as indicated) and could be accumulated elsewhere by any meanseven simply falling down inside a tubular cavity inside the rod (6) or into some other cavity. It is further possible that the diameter of the sprocket could be changed as the rod (6) rotates by driving one side of the sprocket relative to the other side by means of a threaded mechanism (13) into a threaded block (14), this could enable the manipulation of relative feed rates to either create a constantly balanced system or some different effect.

(74) FIG. 20.

(75) Illustrates an automated or motorised screen assembly and particularly illustrates various places where the motor M can be placed.

(76) FIGS. 21-25 illustrate various drum configurations.

(77) Winding the line member onto the drum or cone in a controlled manner gives a very predictable outcome in operation of the system. If the winding on is uncontrolled, then the line member may become trapped amongst other wraps causing it to catch and drag upon unwinding.

(78) FIG. 21.

(79) This is the most preferred embodiment. The line member is a nylon coated stainless steel cable of small diameter (about 1 mm) which is wound onto a conical shaped drum member. The drum member does not have a smooth face, but rather has a spiral thread detail cut into it such that the line member has a continuous groove to lay into.

(80) This groove serves two functions: 1) It eliminates the tendency for the line member to slip towards the smaller diameter of the tapered cone; and 2) It precisely controls the position of the line member on the cone such that it is guided into the groove by the angled sides of the groove itself eliminating the need for a feeding device (such as in some fishing reels and other bobbin winders) to control the distribution of the cable onto the surface of the drum. This is made possible because there is only ever 1 layer of cable on the drum.

(81) As the vertical stile is moved away from the rod onto which it was furled (deploying more of the membrane across the aperture), a length of cable (5) is wrapped onto the drum. With each wrap of the line member onto the cone, the effective diameter of drum in which the groove is recessed, decreases by the same amount as the diameter of the roll of flexible membrane has decreased. If this relationship is largely identical, then the system can be said to be balanced, no extension or contraction of the biasing means (3) will result as the vertical stile member is moved from one position to another, and the stile member will have no tendency to move from any position in which it is left.

(82) FIG. 22.

(83) The drum shape is a simple cylinder. The line member is a simple cord or wire and wraps side by side on the drum (no building of the effective diameter of the drum caused by multiple layers of line member). At only one position in the travel of the vertical stile member can the effective diameter of the roll of flexible membrane be equal to the effective diameter of the line member wrapping onto the drum, and only at this one location will the system be balanced. As the vertical stile member is moved away from the balance position the biasing means (3) are extended (which requires the input of energy), so the tendency of the system is to always move towards the balanced pointthe lowest energy state.

(84) FIG. 23.

(85) The drum shape is multiple cylinders of different diameters (e.g. stepped). As the line member wraps along the drum it steps from one effective diameter to the next. The resultant outcome is that it is now possible to have multiple positions at which the system can be said to be balanced. This configuration may have a difficulty of controlling the line member across the transition from one diameter to the next.

(86) FIG. 24.

(87) The drum shape has a tapered cone at either end, and possibly a short parallel portion at or about its centre. Another similar shape may be a barrel shape. The effect of this shape of drum would be to have a single point or zone near the middle of the range of travel where the system is balanced, and outside of this zone the system will be biased towards being fully deployed or fully closed. This may be an ideal situation where the screen self closes within the normal range of operation, has a balanced zone at which the screen can be temporarily left with no need to hold it in this partly open position, but upon initiating putting the unit away for storage, it actually self retracts.

(88) FIG. 25.

(89) The drum shape is a reverse barrel. The result would be the strong tendency for the vertical stile member (4) to move toward the neutral position somewhere near the middle of the aperture.

(90) Lateral Adjustment

(91) A door frame (or similar frame for other purposes) is usually manufactured in a factory from 4 basic linear members cut to length and fixed together at 4 corners. It is generally possible to manufacture the frame as a fairly accurate rectangle. When it is taken to a building site and installed into its intended position, however, the reality is that the largely vertical jamb members are just thatlargely vertical. In fact it is quite common for the vertical members to be up to 5 mm or more out of vertical, it will be appreciated that with large door frames it is difficult to achieve a better result without much time and care.

(92) FIG. 26

(93) A parallelogram is shown to represent an installed door frame which has side jambs that are out of vertical by a distance d, where the corners are substantially out of square. A simple means of adjusting the position of rod element (6) from position (6a) where it is largely parallel to the frame edge by a compensating distance d to position (6b) where it is ideally vertical at least in this one plane, is desirable.

(94) FIG. 27

(95) A screw adjustable mechanism is illustrated where the assembled unit of drum (1) and rod member (6) are attached to a block member (21) via a pin or bearing member (to enable rotation of the drum and rod assembly) which is has at one position a tapped hole or recess into which is engaged a threaded bolt or screw member (20), some part of which is engaged into a secondary block member (22) which is in turn fixed to the door frame (23). The bolt (20) can be attached to block (22) in such a way that it has only one degree of freedom with respect to block (22)it can rotate. Rotation of the bolt (20) will cause the threaded portion of it which is engaged into block (21) to induce a linear movement of block (21) along the axis of the boltas indicated by the double headed arrow. A screw driver (24) or similar instrument (Allen key etc) can the be used as a simple means of adjusting the assembly to a substantially vertical position.

(96) FIG. 28

(97) A cam mechanism is used to drive the relative positions of blocks (21) and (22) instead of a threaded screw or bolt. A cam with 2 substantially round surfaces with axis offset by a distance d/2, will induce relative movement of distance d by turning through an angle of 180 degrees.

(98) FIG. 29

(99) A screw (25) is used to fix block (21) to block (22)with one or both of these blocks having a slotted hole which allows movement along the desired axis of adjustment travel, when the screw (25) is loosened. Some engaging means (such as serrated teeth or grooves) in the two blocks will ensure positive location when the fixing screw (25) is tightened, but this is not absolutely necessaryfriction between the 2 mating blocks may be sufficient.

(100) FIG. 30

(101) A restraining device (26) is used to maintain engagement between teeth on block (21) and a mating set of teeth on block (22). To release the engagement, a levering device (24) is used to flex a bendable portion of block (21) away from block (22) so that the teeth are disengaged and relative movement is enabled.

(102) Referring now to FIG. 31, there is illustrated a screen assembly and particular emphasis, in this figure is placed on the rod member 6. In FIG. 31, there is illustrated a torsion spring 3. One end 29 of the spring is attached to a tubular rod member 6. The other end 28 of the spring is attached to the rod member and to the drum 1 such that drum 1 is able to rotate relative to rod member 6 about a common axis. Such relative rotation will induce torsion into the spring.

(103) The system can be pretensioned with a linear spring in other embodiments with a difference that any differential length of winding fabric 2 and line member 5 as the vertical stile member 8 is moved, will be absorbed by relative rotation of the drum 1 to the rod member 6.

(104) FIG. 32 illustrates a similar system with a cable joiner and just one drum at either the top or the bottom of the rod member 6.

(105) FIG. 33 more clearly illustrates that as the drum 1 is fixed to rod 6, the drum and the rod turn together. Thus as the flexible membrane 2 comes off one side of its roll, the line member 5 rolls onto the opposite side of the drum 1. This may be the case in the previous embodiments.

(106) It will be appreciated that there are other means for controlling the relative positioning of the end of the rod or tube onto which the fabric are rolled with respect to the frame. It will further be appreciated that this adjustment could be done at the top or at the bottom of the rod or tube assemblyor indeed both.

(107) Some other parts of the present invention which are considered to provide desirable features to the invention are as follows: 1. Springs in the stile (not tube) a. Separate spring adjustment for top and bottom of screen b. Easy access for initial adjustment during installation and also for readjustment if required c. Easy for the installer to visualize the function of each component and how it is performinghe can see if the elements move as they are supposed to etc. 2. Cable aligned with cloth to eliminate torque on stile 3. Cables offset and at different heights so they don't clash on a double screen unit 4. Lateral screw adjustment for jambs out of plumb 5. Framing system integral with door & screen 6. Spring tension (biasing means), combined with the Balanced force provides a safe (no recoil, very little inertia) cushioning system against human impact 7. Lateral adjustment.

(108) Throughout the specification and the claims (if present), unless the context requires otherwise, the term comprise, or variations such as comprises or comprising, will be understood to apply the inclusion of the stated integer or group of integers but not the exclusion of any other integer or group of integers.

(109) Throughout the specification and claims (if present), unless the context requires otherwise, the term substantially or about will be understood to not be limited to the value for the range qualified by the terms.

(110) It should be appreciated that various other changes and modifications can be made to any embodiment described without departing from the spirit and scope of the invention.