AU2010241516A1 - A spring and roller tube arrangement for a retractable member and a retractable screen - Google Patents

Abstract

A spring and roller tube arrangement 10 is disclosed which includes a roller tube 12 and a spring 14 received therein for biasing it to rotate. The arrangement 10 also 5 includes one spring mounting member 16 on which one end of the spring 14 is mounted, and a roller tube mounting formation 20. The arrangement 10 also includes a rotatable end mounting member 22 for rotatable mounting to a support and a roller tube mounting formation 28. The arrangement 10 also includes another spring mounting member 30 on which the other end of the spring 14 is mounted, a fixed 0 end mounting member 36 that resists rotation thereof, and a sleeve support body 34 intermediate the spring mounting member 30 and the end mounting member 36. The member 30, body 34 and member 36 are fixed together to form one unit. Further a rotating sleeve 42 having a roller tube mounting formation 44 is rotatably mounted on the sleeve support body 34. The roller tube mounted on end mounting member 5 22 and rotating sleeve 42 is operatively connected to one spring end through spring mounting member 16. By contrast the end mounting member 36 which resists rotation with the roller tube is connected through the body 34 and the spring mounting member 30 to the other end of the spring. 0 FIG 2 FOR PUBLICATION -1

Description

1 A SPRING AND ROLLER TUBE ARRANGEMENT FOR A RETRACTABLE MEMBER AND A RETRACTABLE SCREEN 5 FIELD OF THE INVENTION This invention relates to a spring and roller tube arrangement for a retractable member. The invention also extends to a spring and roller tube mounting 0 arrangement for a roller tube and also to a retractable screen including the spring and roller tube arrangement. Further the invention also extends to a method of assembling a retractable screen. The invention relates particularly to a spring and roller tube mounting arrangement 5 for a retractable screen that is an insect screen extending an architectural opening such as a doorway and it will be convenient to hereinafter describe the invention with reference to this example application. However it is to be clearly understood that the invention is capable of broader application. For example the invention applies equally to a spring for a roller assembly for retractable screens that are not insect -O screens. Yet further the invention also extends to screens that extend across other architectural openings such as window openings, sky lights, roof windows, and security screens. In the specification the term "comprising " shall be understood to have a broad 25 meaning similar to the term "including" and will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps. This definition also applies to variations on the term "comprising" such as "comprise" and "comprises". 30 2 BACKGROUND TO THE INVENTION A retractable screen comprises a flexible sheet of screen material that is rolled up in a roll form on a roll tube in a stored condition. The sheet of material can be drawn 5 off the roll tube and pulled across an architectural opening such as a door opening or a window opening where it forms a screen across the opening, in a deployed condition. The retractable screen comprises broadly a fixed support post which is mounted on 0 one side of the door and is attached to one end of the screen material and a receiver post that is attached to the opposed end of the screen material. The receiver post is displaced from a position adjacent to the fixed support post when in the stored condition to the other side of the opening when the screen is moved to the deployed condition in use. Typically the receiver post has a handle mounted thereon for 5 enabling a user to manually displace the receiver post from the stored to the deployed condition. The roller tube and the screen material thereon are mounted on end supports and received within a housing that is mounted on the fixed support post in a vertically 0 extending orientation. The retractable screen includes a spring that is a torsion spring for biasing the screen material to a rolled up or stored condition. That is it will tend to roll the screen material onto the roller tube. The screen material can be manually drawn off the 25 roller tube by a user applying a manual force to the receiver post that overcomes the resistance of the spring. The screen can then be braked in the deployed condition and when the brake is released the spring draws the screen material back onto the roller tube. 30 A retractable screen is a popular contrivance for screening of an opening because the screen material rolls up into a compact roll form in the store condition. This 3 thereby opens up the full width of the opening, e.g. the doorway. This has the effect of opening up the doorway when the screen is in the stored condition and is not is use. This is the reason why a retractable screen is sometimes referred to as a disappearing screen. 5 It would be advantageous if a spring and roller tube mounting arrangement could be devised that conferred some advantages over prior art contrivances. This improvement would lead to improved retractable screens. o The reference to any prior art in this specification is not and should not be taken as an acknowledgement or any form of suggestion that the referenced prior art forms part of the common general knowledge in Australia. SUMMARY OF THE INVENTION 5 According to one aspect of this invention there is provided a spring and roller tube arrangement for a retractable member, the arrangement including: a roller tube; a spring received within the roller tube for biasing the roller tube to rotate; 20 one spring mounting member having a spring engaging formation on which the spring is mounted and a roller tube mounting formation on which the roller tube is mounted; a rotatable end mounting member having an end mounting formation for mounting the mounting member to an end support so that it can rotate relative 25 thereto, and a roller tube mounting formation on which the roller tube is mounted; another spring mounting member having a spring engaging formation on which the spring is mounted at a position on the spring spaced from said first spring mounting member; 4 a fixed end mounting member having an end mounting formation for mounting the mounting member to another end support in such a way that it resists rotation relative to the fixed support, the fixed end mounting member being directly or indirectly coupled to the further spring mounting member; and 5 a sleeve support body that is positioned in line with the other spring mounting member and the fixed end mounting member; a rotating sleeve that is rotatably mounted on the sleeve support body, the rotating sleeve having a roller tube mounting formation on which the roller tube is mounted; and 0 whereby rotation of the roller tube causes said one spring mounting, the rotatable end mounting member, and the rotating sleeve to rotate therewith, while the other spring mounting member and the fixed end mounting member are held against rotation whereby to influence tension within the spring. 5 The other spring mounting body may be operatively coupled to the sleeve support body which in turn may be coupled to the fixed end mounting member, whereby to hold said other spring mounting body against rotation when the roller tube rotates. In particular the other spring mounting formation and the fixed end mounting member may be fixed to each other so that they work as one unit and do not move relative to 0 each other. Conveniently these components may be integrally formed as one article. The rotating sleeve may be open at each end and be sized to be mounted over the sleeve support body with a working clearance for enabling it to rotate freely on the sleeve support body, e.g. without encountering significant frictional resistance. 25 The sleeve support body may have an axial length that is substantially greater than an axial length of the rotating sleeve. The roller tube may have one end which is mounted on the roller tube mounting 30 formation of said rotatable end mounting formation, and another end that is mounted 5 on the roller tube mounting formation of the rotating sleeve. The roller tube may also be mounted on the roller tube mounting formation of said one spring mounting member intermediate the roller tube ends. 5 The spring may be a torsion spring having a plurality of tightly wound coils that generally form a cylindrical spring body defining body openings at each end thereof and defining a spring passage therethrough from one body opening to the other body opening. The spring may have two spring end regions, and said one spring mounting member may be mounted on one end region of the spring, and said other 0 spring mounting member may be mounted on the other end region of the spring. Each spring mounting formation may have a broadly cylindrical outer surface that can be inserted into an open end of the spring body. Further each spring mounting formation may also be tapered to assist its insertion into the open end of the torsion 5 spring. The roller tube mounting formation of said one spring mounting formation may comprise a substantially cylindrical tube mounting body that is sized to be received snugly within the roller tube with a tight fit so that it is held by the roller tube and 0 rotates with it. Further each spring mounting formation may have formations on its outer cylindrical surface for engaging with complementary formations on an internal surface of the roller tube whereby to key the spring mounting formation to the roller tube. 25 The end mounting formation of the rotatable end mounting member may be configured with a round surface in a way that facilitates its rotation on its end support. In particular the end mounting formation may comprise a round spigot that is received within a complementary formation that is a round opening or socket on 30 the end support, whereby to permit the roller tube and the rotatable end mounting member to rotate on the support.

6 The roller tube mounting formation on the rotatable end mounting member may comprise a substantially cylindrical tube mounting body that is sized to be received snugly within the roller tube. 5 The tube mounting body may be similar to the tube mounting body on said one spring mounting member. For example the tube mounting body may have formations for engaging with complementary formations on an internal surface of the roller tube thereby to cause the roller tube to rotate with the rotatable end mounting 0 member. The rotatable end mounting member may further include a stop formation that locates the end mounting member on the end of the roller tube. The stop formation may be sized to resist being inserted into the roller tube and thereby locate the end 5 mounting member. The roller tube mounting formation on the rotating sleeve may be formed by an outer surface of the rotating sleeve. eo The outer surface of the rotating sleeve may have formations on its outer cylindrical surface for engaging with complementary formations on an internal surface of the roller tube thereby to hold the roller tube against rotation relative to said rotating sleeve. The formations on the rotating sleeve may comprise a plurality of axially extending protrusions spaced apart from each other around the circumference of the 25 tube mounting body. The rotating sleeve may further include a stop formation that is sized to resist being inserted into the roller tube and thereby locate the rotating sleeve on the end of the roller tube. 30 7 Thus the rotatable end mounting member, said one spring mounting member and the rotating sleeve are all keyed to the roller tube so as to rotate therewith. The sleeve support body may include a sleeve stop formation at the end thereof that 5 is proximate to the fixed end mounting member and that functions as a stop for the rotating sleeve. Conveniently the stop may be in the form of a radial outward projecting flange that is proud of the sleeve support body at the end of the body. The end support engaging formation on the fixed end mounting member may be 0 configured for mounting on said other end support in a way that resists rotation thereof. In particular the end support engaging formation may be in the form of a non-circular spigot for engaging a complementary non-circular socket in the end support whereby to hold the other spring mounting member against rotation relative to the support. In one example form the spigot may have a rectangular cross 5 sectional shape and the socket may define a complementary rectangular shape. The spring and roller tube arrangement may further include a housing circumferentially surrounding the roller tube. The housing may include one housing end formed by the end support on which the rotatable end mounting member is 0 mounted, and another housing end formed by the other end support on which the fixed end mounting member is mounted. The housing may also include a housing cover extending between the housing ends that is operatively mounted to the housing ends, e.g. in a removable fashion. The housing ends in turn may be mounted to an external structure, e.g. a vertically extending fixed post. 25 The arrangement may further include an elongate spring support member that is passed through the spring body formed by the spring. The elongate spring support member may have one end mounted to the one spring mounting member and the other end mounted to the other spring mounting member. The rod provides a spine 30 for the arrangement and helps to support it as a unit.

8 In particular each of said one and other spring mounting members may include openings, e.g. blind openings, and the ends of the elongate spring support member may be received within said openings. The elongate spring support member may be in the form of a rod having some rigidity, e.g. an elongate rod made of a substantially 5 rigid plastic material. According to another aspect of this invention there is provided a retractable screen including a spring and roller tube arrangement as defined above in the preceding aspect of the invention. 0 The spring and roller tube arrangement may include any one or more of the optional features of the spring and roller tube arrangement defined in the first aspect of the invention above. 5 The retractable screen may further include a roller tube which is mounted on the spring and roller tube mounting arrangement. The roller tube may be mounted on the roller tube mounting formation of said one spring mounting member, e.g. at one end of the spring, and the rotatable end 0 mounting member, e.g. at one end of the roller tube. The roller tube may also be mounted on the roller tube mounting formation of the rotating sleeve. The screen may further include a roll of screen material in sheet form that is mounted on the roller tube. The roll of screen material may be a mesh that is sized 25 to resist the passage of insects there through. The screen may include one end support for rotatable engagement with the support engaging formation on the rotatable spring mounting member.

9 The screen may further include another end support for fixed engagement with the support engaging formation on the fixed spring mounting member. The screen may yet further include a housing circumferentially surrounding the roller 5 tube and the roll of sheet screening material and extending between the one and other end supports. According to another aspect of this invention there is provided a spring and roller tube mounting arrangement for mounting a roller tube thereon, the arrangement 0 including: a torsion spring having two ends; one mounting arrangement for mounting one end of the spring to the roller tube; another mounting arrangement for mounting the other end of the spring to the 5 support such that it is held against rotation when the roller tube is rotated, while permitting the roller tube to rotate relative to said other mounting arrangement; and a yet further mounting arrangement for mounting the roller tube to the support in such a way that the roller tube and said one spring end rotates relative to the support. e0 The yet further mounting arrangement may mount the roller tube over the spring such that it can rotate relative to at least part of the spring towards the other end thereof. 25 Said one mounting arrangement may comprise a mounting member that is mounted to the roller tube and said yet further mounting arrangement may be mounted on an end of the roller tube spaced a short distance away from said one mounting arrangement.

10 Said other mounting arrangement may a further mounting member that has one end that is operatively coupled to the other end of the spring and another end that is operatively coupled to the support on which roller tube is rotatably mounted. The other end of the roller tube may be mounted on a rotating sleeve that is in turn 5 mounted over said further mounting member and is able to rotate therewith. According to another aspect of this invention there is provided a spring and roller tube mounting arrangement, the assembly including: a spring that is receivable within a roller tube for applying a rotational bias to 0 the roller tube; one spring mounting member having a spring engaging formation on which the spring is mounted and a roller tube mounting formation on which the roller tube is mountable; a rotatable end mounting member having an end mounting formation for 5 mounting the mounting member to a support so that it can rotate relative thereto, and a roller tube mounting formation on which the roller tube is mountable; another spring mounting member having a spring engaging formation on which the spring is mounted at a position on the spring spaced from said first spring mounting member; 0 a fixed end mounting member having an end mounting formation for mounting the mounting member to another end support in such a way that it resists rotation relative to the support, the fixed end mounting member being directly or indirectly coupled to the further spring mounting member; and whereby said one spring mounting rotates in use with the roller tube while the 25 other spring mounting member is held by the support, whereby to influence tension within the spring when the roller tube is rotated. The spring and roller tube mounting arrangement may further include a sleeve support body that is positioned intermediate the other spring mounting member and 30 the fixed end mounting member, and a rotating sleeve that is rotatably mounted on 11 the sleeve support body, the rotating sleeve having a roller tube mounting formation on which the roller tube is mounted. The other spring mounting body may be operatively coupled to the sleeve support 5 body which in turn is coupled to the fixed end mounting member, whereby to hold said other spring mounting body against rotation when the roller tube rotates. The sleeve support body may have an axial length that is substantially greater than an axial length of the rotating sleeve, e.g. a length of 70 to 120mm. 0 The invention also extends to a method of manufacturing a retractable screen having a spring and roller tube in accordance with the preceding aspects of the invention. According to another aspect of the invention there is provided a method of 5 manufacturing a spring and roller tube arrangement for a retractable member including: a roller tube; a spring received within the roller tube for biasing the roller tube to rotate; one spring mounting member having a spring engaging formation on which 20 the spring is mounted and a roller tube mounting formation on which the roller tube is mounted; a rotatable end mounting member having an end mounting formation for mounting the mounting member to an end support so that it can rotate relative thereto, and a roller tube mounting formation on which the roller tube is mounted; 25 another spring mounting member having a spring engaging formation on which the spring is mounted at a position on the spring spaced from said first spring mounting member; a fixed end mounting member having an end mounting formation for mounting the mounting member to another end support in such a way that it resists rotation 12 relative to the fixed support, the fixed end mounting member being directly or indirectly coupled to the further spring mounting member; and a sleeve support body that is positioned in line with the other spring mounting member and the fixed end mounting member; 5 a rotating sleeve that is rotatably mounted on the sleeve support body, the rotating sleeve having a roller tube mounting formation on which the roller tube is mounted; and whereby rotation of the roller tube causes said one spring mounting, the rotatable end mounting member, and the rotating sleeve to rotate therewith, while the 0 other spring mounting member and the fixed end mounting member are held against rotation whereby to influence tension within the spring, the method including: mounting the rotatable end mounting member on the support; displacing the fixed end mounting member and the sleeve support body in a direction away from the rotatable end mounting member; 5 manually rotating the fixed end support member and thereby also the other end of the spring relative to the roller tube and said one end of the spring which remain stationary thereby to tension the spring; and then mounting the fixed end support back on the other end support so that it is fixedly held thereon while retaining the tension in the spring effected by the manual 0 rotation. Mounting the fixed end support back on the other end support may include displacing the fixed end mounting member and the sleeve support body in a direction towards the rotatable end member back to their original position. 25 The method may also include an initial step of mounting the rotatable end mounting member on the support; The method may include a further initial step of detaching the fixed end mounting 30 member from its end support before displacing the fixed end support member and 13 the sleeve support body in a direction axially away from the rotatable end mounting member. BRIEF DESCRIPTION OF THE DRAWINGS 5 The present invention will be understood more fully from the detailed description given hereinafter of one example embodiment of the invention and from the accompanying drawings of this embodiment. This description should not be taken to be limiting of the invention, but for explanation and understanding only. 0 Figure 1 is a three dimensional view of a spring and roller tube mounting arrangement in accordance with one embodiment of the invention; Figure 2 is an exploded three dimensional view of the spring and roller tube mounting arrangement shown in Figure 1; 5 Figure 3 is a three dimensional view of a spring and roller tube mounting arrangement of Fig 1 when viewed from the opposite direction to Figure 1; Figure 4 is a three dimensional cut away view of the spring and roller tube mounting arrangement shown in Figure 1 showing a rotating sleeve in one position; Figure 5 is a three dimensional cut away view of the spring and roller tube 20 mounting arrangement shown in Figure 1 showing a fixed end mounting member spaced away from the rotating sleeve; Figure 6 is a three dimensional view of a retractable screen including the spring and roller tube mounting arrangement shown in Figure 1; Figure 7 is a three dimensional cut away view of part of the retractable screen 25 shown in Fig 5; and Figure 8 is a front view of a retractable screen in a deployed condition in which the screen material extends across a door opening.

14 DETAILED DESCRIPTION OF THE INVENTION In Figures 1 to 4 reference numeral 10 refers to a spring and roller tube mounting arrangement for a retractable member. The roller tube has not been shown in the 5 drawings for reasons of clarity. However it would be mounted circumferentially over the mounting arrangement 10. In this specification a spring and roller tube arrangement shall be understood to mean the mounting arrangement 10 shown in the drawings with a roller tube mounted thereon. o The spring and roller tube arrangement 10 (hereinafter the arrangement 10) comprises broadly a roller tube 12 (shown in Figures 6 and 7) and a spring 14 received within the roller tube 12 for rotating the roller tube 12. The arrangement 10 also includes one spring mounting member 16 having a spring engaging formation 18 on which one end of the spring 14 is mounted and a roller tube mounting 5 formation 20 on which the roller tube 12 is mounted. The arrangement 10 further includes a rotatable end mounting member 22 having an end mounting formation 24 that is rotatably mounted to an end support 26 (shown in Figure 6) and a roller tube mounting formation 28 on which the roller tube 12 is mounted. The rotatable end mounting member 22, mounted on the end of the roller tube, is spaced a short away 0 along the length of the roller tube 12 from said one spring mounting member 16 which is mounted on the end of the spring. The arrangement 10 also includes another spring mounting member 30 having a spring engaging formation 32 on which the other end of the spring 14 is mounted and 25 a sleeve support body 34 that is operatively coupled to one end of the other spring mounting member 30 and extends away therefrom. Yet further the arrangement 10 includes a fixed end mounting member 36 having an end mounting formation 38, at an end of the sleeve support body 34 that is remote 30 from the other spring mounting member 30. The end mounting formation 38 is 15 configured such that it is mounted to an end support 40 (shown in Figure 6) in such a way that it resists rotation relative to the end support 40. The arrangement also includes a rotating sleeve 42 that is rotatably mounted on the 5 sleeve support body 34. The rotating sleeve 42 has a roller tube mounting formation 44 on which the roller tube 12 is mounted. Each of these components will now be described in more detail with reference to the accompanying drawings. 0 The roller tube 12 (which is shown in Figures 6 and 7) is substantially cylindrical and has two opposed ends. One end 46 is mounted on the roller tube mounting formation 28 and another end 48 is mounted on the roller tube mounting formation 44. 5 The spring 14 is a torsion spring having a plurality of tightly wound coils that generally form a cylindrical spring body forming openings at each end thereof and defining a spring passage extending between the open ends. The spiral spring member itself has two spring end regions 52, 54 and said one spring mounting 0 member 16 is mounted on the end region 52 of the spring 14 and said other spring mounting member 30 is mounted to the other end region 54 of the spring 14. As described above each of the one and other spring mounting members 16, 30 has a spring engaging formation 18, 32 thereon. Each of said spring mounting formations 25 18, 32 is a body having a broadly cylindrical outer surface that can be inserted into an open end of the spring body. Further the cylindrical outer surface of each spring mounting formation 18, 32 may taper inwardly towards its free end, e.g. slightly, to assist its insertion into the open end of the cylindrical spring body. Each spring mounting formation 18, 32 is sized so that it grips the adjacent coils of the spring 30 body, with which it engages, with a friction grip so that it does not rotate relative to the spring 14 in use. The spring mounting formations 18, 32 can be formed from a 16 plastics material and the engagement of the coils of the spring 14 therewith can form impressions in the outer surface of the spring mounting formation 18, 32. For example the coils of the spring 14 can form thread formations on the spring mounting formation 18 or 32 which helps to key the spring 14 onto the spring mounting 5 formation 18, 32. As described above the spring mounting member 16 also includes a roller tube mounting formation 20 which comprises a substantially cylindrical tube mounting body. The tube mounting body has a diameter that is greater than the spring 0 mounting formation 18 which is received within the spring 14. In some forms the tube mounting body has a diameter that is 20 to 40 % larger than the diameter of the spring mounting formation 18 at its widest point. The tube mounting body is sized to be received snugly within the roller tube 12 with a tight fit so that it is held by the roller tube 12 and rotates with it. 5 Further as shown in the drawings the tube mounting body has formations 60 on its outer cylindrical surface for engaging with complementary formations on an internal surface of the roller tube 12. This helps to key the mounting formation 20 to the roller tube 12 so that it is fast therewith. In the illustrated embodiment the formations 0 60 comprise a plurality of axially extending protrusions spaced apart from each other around the circumference of the tube mounting body. Turning now to the rotatable end mounting member 22 described above, the end support engaging formation 24 is in the form of a round spigot that is received within 25 a complementary round opening or socket on the end support 26. This mounting permits the rotatable end mounting member 22 and thereby also the roller tube 12 to rotate on the end support 26. The roller tube mounting formation 28 on the rotatable end mounting member 22 comprises a substantially cylindrical tube mounting body that is similar to the tube mounting body described above. One difference is that the 30 tube mounting body described here is hollow whereas the tube mounting body on the spring mounting member 16 is solid.

17 The rotatable end mounting member 22 further includes a stop formation 66 that limits travel of the tube mounting body into the open end of the roller tube 12. The stop formation 66 is sized to resist being inserted into the roller tube 12 and thereby 5 locate the end mounting member 22 on the end of the roller tube 12. As shown in the drawings, the spring mounting formation 32 of the other spring mounting member 30 is similar to the spring mounting formation 18. The sleeve support body 34 extends from one end of the spring mounting formation 32. As 0 shown in the drawings the sleeve support body 34 has a larger diameter than the spring mounting formation 32 at its widest point. The illustrated sleeve support body 34 has an axial length of at least three times the axial length of the rotating sleeve 42, e.g. a length of about 80 to 90 mm. This permits the sleeve support body 34 to be displaced axially relative to the rotating sleeve 42 when the spring 14 is being 5 tensioned by manual rotation of the fixed end mounting member 36, e.g. during assembly of the screen either during manufacture or during maintenance. When this occurs the rotating sleeve 42 remains mounted on the sleeve support body 34. The sleeve support body 34 has a stop formation 68 in the form of a circumferential 0 flange at the end thereof that is remote from the spring mounting formation 32. The stop formation 68 functions to limit travel of the rotating sleeve 42 in an axial direction along the sleeve support body 34 away from the spring mounting formation 32. 25 The rotating sleeve 42 has a substantially cylindrical outer surface that forms the roller tube mounting formation 44. The outer surface has formations 60 like the formations 60 on the spring mounting member 16 for keying the sleeve 42 to the roller tube 12. It also has a stop formation like the stop formation 66 on member 22. 30 The fixed end mounting member 36 at the end of the sleeve support body 34, has an end mounting formation 38 in the form of a non-circular spigot for engaging a 18 complementary non-circular socket in the end support 40. This stops the member 36 from rotating on the end support 40. In the illustrated embodiment the spigot 38 has a rectangular cross-sectional shape engaging a complementary rectangular socket. This way the other spring mounting member 30, the sleeve support body 34 and the 5 fixed end mounting member 36 are integrally formed and thus work as a single unit and do not move relative to each other. The arrangement 10 further includes an elongate spring support member 70 in the form of a substantially rigid plastic rod that is passed through the spring body of the 0 spring 14. By making the rod of plastic material it is less prone to rattling when the arrangement 10 is used. The rod 70 has one end 72 attached to said one spring mounting member 16 and the other end 74 attached to said other spring mounting member 30. In the illustrated embodiment each of said one and other spring mounting members 18, 30 have blind openings within which the ends 72, 74 of the 5 rod 70 are received. The spring and roller tube arrangement 10 further includes a housing 76 enclosing the roller tube 12 as shown in Figures 6, 7 and 8. The housing 76 comprises one housing end formed by the end support 26 and another housing end formed by the 0 other end support 40. It also includes a housing cover 78 extending between the housing ends 26, 40 that is removably mounted on the housing ends. In use rotation of the roller tube 12 causes said one spring mounting member 16, the rotatable end mounting member 22, and the rotating sleeve 42 to rotate therewith, 25 while the other spring mounting member 30 and the fixed end mounting member 36 are held against rotation. Thus rotation of the roller tube 12, e.g. by a person, causes the spring end regions 52, 54 to be rotated relative to each other. Depending on the direction of rotation this will either increase tension in the spring 14 or reduce tension in the spring 14. 30 19 During use of the arrangement 10, the roller tube 12 is rotated when roll material is drawn off the tube. This rotates the spring mounting member 16 and the rotatable end mounting member 22 which in turn rotates the associated end region 52 of the spring 14. The other end region 54 of the spring is held by the spring mounting 5 member 30 and the fixed end mounting member 36 to the support or housing against rotation. This thereby increases the tension within the spring 14. Consequently when the roll material that has been drawn off the roller tube is released, the spring energy within the spring causes the roller tube to rotate in the opposite direction and roll the roll material back onto the roller tube. 0 The spring 14 is tensioned by the relative rotation that is caused by the fact that one end 52 thereof is operatively coupled to the roller tube, and the end thereof 54 is effectively coupled to the support on which the roller tube 12 is mounted. 5 Figure 5 illustrates the sleeve support body 34 in a condition in which it is displaced axially relative to the rotating sleeve 42 when compared with Figure 4. The fixed mounting member 36 can be manually removed by a person from its mounting on the other end support 40 and be displaced axially outward away from 0 the roller tube 12. This causes the sleeve support body 34 to move axially relative to the rotating sleeve 42 which is mounted on the adjacent end of the roller tube 12. The person can then manually rotate the sleeve support body 34 relative to the rotating sleeve 42 which is held in position by the roller tube 12 and the screen 25 material mounted on the roller tube 12. Rotation of the sleeve support body 34 in one direction has the effect of rotating the end region 54 of the spring 14 relative to the end region 52 which is coupled to the roller tube 12 and which is stopped from rotating as described above. This causes increased tension to be applied to the spring. Once there is sufficient tension in the spring 14 the fixed end mounting 30 member 36 can be returned to its installed position with the end mounting formation 38 received within the corresponding socket on the end support 40. The ability to 20 slide the sleeve support body 34 away from the sleeve 42 on the end of the roller tube 12, and the screen mounted thereon, considerably eases this process. The axial length of the sleeve support body 34 which is much longer than the rotating sleeve 42 permits this to be done. 5 Figures 6 to 8 illustrate a retractable screen in accordance with one embodiment of the invention having the spring and roller tube arrangement described above with reference to Figures 1 to 4. In these drawings the retractable screen is indicated generally by the reference numeral 80. 0 The retractable screen 80 has a spring and roller tube arrangement 10 as described above with reference to Figures 1 to 4. The screen 80 includes a housing 76 that is mounted over the roller tube 12. The housing 76 comprises a main cover 78 and two housing ends formed by the end supports 26, 40 described above with reference to 5 Figures 1 to 4. The screen 80 has a roll of screen material 82 that is mounted on the roller tube 12 having a free end 84 that can be drawn off the roll 82 and an inner end (not shown) that remains on the roller tube 12 during all stages of operation. The free end of 0 screen material 84 can be drawn off the tube and then fixed in position extending across an opening. When the free end 84 of the screen material is released the tension in the spring 14 winds the screen material back onto the roller tube 12. The retractable screen 80 has a fixed support post 86 on which the housing 76 is 25 mounted and a receiver post 88 that is attached to the free end 84 of the screen material on the roller tube 12. Accordingly when the receiver post 88 is displaced away from the fixed support post 86 the roll material is drawn off the roller tube 12 in the manner described above. In the illustrated embodiment the screen is an insect screen and the screen material is a flexible mesh material having appropriately sized 30 openings for stopping flying insects.

21 In use the spring and roller tube arrangement 10 winds the screen material 82 back onto the roller tube 12 once the receiver post 88 is released. Further during manufacture of the spring the construction illustrated above with 5 reference to the drawings is particularly useful. This because it permits the fixed end mounting member 36 and the sleeve mounting body 34 and other spring mounting member 30 to be displaced in an axial direction relative to the rotating sleeve 42 and the roller tube 12 mounted thereon. This feature enables a person to pull the end mounting formation axially away from the adjacent end of the roller tube and the 0 rotating sleeve when they manually rotate the end mounting formation during manufacture in order to tension the spring. This provides more space for a user's hand to perform this rotation than when their hand is up against the end of the roller tube. Once the spring has been suitably tensioned the user can insert the end mounting formation into its socket on the end support that holds it against rotation 5 during operation of the screen. Further during manufacture of the screen, a person extends the length of the spring 14 to conform it to the length of the rod 70. This stretching out of the spring ensures that there is sufficient space to receive the spring in its various conditions, e.g. when 0 it is wound up and/or released, during normal operation of the spring and the screen. An advantage of the spring and roller tube mounting arrangement described with reference to the drawings is that it provides a compact and effective arrangement that is not overly complicated yet provides reliable and trouble free operation thereof. 25 Yet further the spring and roller tube mounting arrangement can easily be dismounted from the associated support for maintenance operations such as replacing screen material. Further the screen can easily be re-assembled and the spring can be suitably tensioned for use when it is re-assembled. The ability of the fixed end mounting member and the sleeve support body to be displaced axially 30 away from the end of the roller tube and the rotating sleeve mounted thereto considerably assists a user in the performance of this operation.

22 It will of course be realized that the above has been given only by way of illustrative example of the invention and that all such modifications and variations thereto, as would be apparent to persons skilled in the art, are deemed to fall within the broad 5 scope and ambit of the invention as is herein set forth.

Claims (20)

1. A spring and roller tube arrangement for a retractable member, the arrangement including: 5 a roller tube; a spring received within the roller tube for biasing the roller tube to rotate in a direction; one spring mounting member having a spring engaging formation on which the spring is mounted and a roller tube mounting formation on which the 0 roller tube is mounted; a rotatable end mounting member having an end mounting formation for mounting the mounting member to an end support so that it can rotate relative thereto, and a roller tube mounting formation on which the roller tube is mounted; 5 another spring mounting member having a spring engaging formation on which the spring is mounted at a position on the spring spaced from said first spring mounting member; a fixed end mounting member having an end mounting formation for mounting the mounting member to another end support in such a way that it 0 resists rotation relative to the fixed support, the fixed end mounting member being directly or indirectly coupled to the further spring mounting member; and a sleeve support body that is positioned in line with the other spring mounting member and the fixed end mounting member; a rotating sleeve that is rotatably mounted on the sleeve support body, 25 the rotating sleeve having a roller tube mounting formation on which the roller tube is mounted; and whereby rotation of the roller tube causes said one spring mounting, the rotatable end mounting member, and the rotating sleeve to rotate therewith, while the other spring mounting member and the fixed end 24 mounting member are held against rotation whereby to influence tension within the spring.

2. A spring and roller tube arrangement as claimed in claim 1, wherein the other 5 spring mounting body is operatively coupled to the sleeve support body which in turn is coupled to the fixed end mounting member, whereby to hold said other spring mounting body against rotation when the roller tube rotates.

3. A spring and roller tube arrangement as claimed in claim 2, wherein the 0 rotating sleeve is open at each end and is sized to be mounted over the sleeve support body with a working clearance for enabling it to rotate freely on the sleeve support body.

4. A spring and roller tube arrangement as claimed in claim 3, wherein the 5 sleeve support body has an axial length that is substantially greater than an axial length of the rotating sleeve.

5. A spring and roller tube arrangement as claimed in claim 4, wherein the spring is a torsion spring having a plurality of tightly wound coils that generally form a 0 cylindrical spring body having open ends and defining a spring passage therethrough, and wherein the spring has two spring end regions and said one spring mounting member is mounted on one end region of the spring and said other spring mounting member is mounted on the other end region of the spring. 25

6. A spring and roller tube arrangement as claimed in claim 5, wherein each spring mounting formation has a broadly cylindrical outer surface that can be inserted into an open end of the spring body, and wherein each spring mounting formation is tapered to assist its insertion into the open end of the 30 torsion spring. 25

7. A spring and roller tube arrangement as claimed in claim 6, wherein the roller tube mounting formation of said one spring mounting formation comprises a substantially cylindrical tube mounting body that is sized to be received snugly 5 within the roller tube with a tight fit so that it is held by the roller tube and rotates with it.

8. A spring and roller tube arrangement as claimed in claim 7, wherein the tube mounting body has formations on its outer cylindrical surface for engaging 0 with complementary formations on an internal surface of the roller tube whereby to key the tube mounting body to the roller tube.

9. A spring and roller tube arrangement as claimed in any one of claims 1 to 8, wherein the end mounting formation comprises a round spigot that is received 5 within a complementary formation that is a round opening or socket on the end support, whereby to permit the roller tube and the rotatable end mounting member to rotate on the support.

10. A spring and roller tube arrangement as claimed in any one of claims 1 to 9, 0 wherein the roller tube mounting formation on the rotatable end mounting member comprises a substantially cylindrical tube mounting body that is sized to be received snugly within the roller tube.

11. A spring and roller tube arrangement as claimed in any one of claims 1 to 10, 25 wherein the roller tube mounting formation on the rotating sleeve is formed by an outer surface of the rotating sleeve.

12. A spring and roller tube arrangement as claimed in any one of claims 1 to 11, wherein the sleeve support body includes a stop formation at the end thereof 26 that is proximate to the fixed end mounting member and that functions as a stop for the rotating sleeve.

13. A spring and roller tube arrangement as claimed in any one of claims 1 to 12, 5 wherein the fixed end mounting member includes an end mounting formation for mounting the spring mounting member on said other end support in a way that resists it from rotating on the end support.

14. A spring and roller tube arrangement as claimed in claim 13, wherein the end 0 mounting formation on the fixed end mounting member is in the form of a non circular spigot for being received within a complementary non-circular socket in the end support whereby to hold the other spring mounting member against rotation relative to the support. 5

15. A spring and roller tube arrangement as claimed in any one of claims 1 to 14, wherein the spring and roller tube arrangement further includes a housing circumferentially surrounding the roller tube.

16. A spring and roller tube arrangement as claimed in claim 15, wherein the 0 housing includes one housing end formed by the one end support on which the rotatable end mounting member is mounted, and another housing end formed by the other end support on which the fixed end mounting member is mounted, and a housing cover extending between the housing ends that is operatively mounted to the housing ends. 25

17. A spring and roller tube arrangement as claimed in claim 15, wherein the arrangement further includes an elongate spring support member that is passed through the spring body formed by the spring and the elongate spring support member has one end coupled to the one spring mounting member 30 and the other end coupled to the other spring mounting member. 27

18. A retractable screen including: a spring and roller tube arrangement as claimed in any one of claims 1 to 17; and 5 a roll of screen material mounted on the roller tube having a free end that can be drawn off the roller tube and an inner end that remains on the roller tube.

19. A retractable screen according to claim 18, further including a housing within 0 which the spring and roller tube arrangement is received.

20. A spring and roller tube arrangement substantially as herein described in the detailed description of the invention with reference to the drawings.