AU724095B2 - Improvements in flexible covers - Google Patents

Description

1

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT A 4 Name of Applicant: Actual Inventor: Address for Service: Invention Title: John Harry HALL As above CULLEN CO., Patent Trade Mark Attorneys, 240 Queen Street, Brisbane, Qld. 4000, Australia.

IMPROVEMENTS IN FLEXIBLE COVERS Details of Associated Provisional Application: No. P00738 1 July 1996 The following statement is a full description of this invention, including the best method of performing it known to me: 2 This invention relates to improvements in flexible covers, such as shade nets or hail nets, and particularly relates to a system whereby a flexible cover can be extended and retracted over a framework.

In the horticultural industry, it is often necessary to provide shade canopies over plants. Shade canopies are typically formed from an array of connected cables which are supported above the ground by a number of vertical posts. Shade cloth or another type of flexible cover is attached to the framework. It is not unusual for these frameworks to be up to 100 metres or more in length and 30 metres or more in width.

Retractable shade systems are known and a variety of mechanisms have been developed to extend and retract the shade cloth over the framework. A disadvantage with existing systems is that they are difficult, cumbersome and expensive to install and maintain. Another disadvantage is that existing retractable systems do not tension the shade cloth to any 20 great extent thereby resulting in uneven shade levels and excessive abrasion of the fabric.

The present invention is directed to a system whereby a flexible cover can be extended and retracted over a framework and which does not require the use of 25 heavy duty motors. The system also allows tensioning of the fabric which thereby improves shade levels and reduces excessive abrasion of the fabric.

It is an object of the invention to provide a system which can overcome the abovementioned disadvantages or provide the public with a useful or commercial choice.

In one form, the invention resides in a system for extending and retracting a flexible cover over a framework, the system comprising a slide member supported by a portion of the framework and slidable along the portion, the flexible cover being connected to the slide member, and means to advance and retract the slide member along the portion.

If the system is used in the horticultural industry, the framework will typically comprise an array of cables, ropes or wires. Such frameworks are well known, and are widely used in the horticultural industry.

Typically, the framework comprises an array of spaced apart parallel north south cables and an array of spaced apart parallel east west cables. The cables can be spliced or otherwise attached to each other and the entire arrangement is supported above the ground surface by a number of end posts and intermediate posts. These posts can be anywhere up to 6 metres in length.

The framework array is typically planar, but can also be domed, peaked or other otherwise configured depending on the required use.

The framework of cables or wires can be tensioned by conventional techniques which include the use of winches and the like.

If a cable type framework is used, the slide member may be connected to a cable and is preferably connected to a cable which extends entirely along or across the framework. To prevent the slide member from being dislodged from the cable, it is preferred that the slide member has a main body having a bore therethrough through which the cable passes, the size of the bore S 25 being larger than the diameter of the cable such that the slide member can freely slide along the cable.

The flexible cover may comprise a fabric such as a knitted fabric, a net, shadecloth, hail netting, plastic sheet, cloth, or any other type of flexible cover which may be used from time-to-time. The type, size and thickness of the cover can vary to suit.

As the flexible cover is attached to the slide member, it is preferred that the slide member has an upwardly extending member forward of, or adjacent to, the leading edge of the flexible cover. One function of the upwardly extending member is to assist in collecting the flexible cover as the slide member is retracted. The upwardly extending member may be curved or hooked and may comprise a metal rod.

The means to advance and retract the slide member may comprise a separate line member. The line member can be attached to the slide to move the slide along as the line member is moved. In one form, the line member may comprise an endless loop supported by spaced apart pulleys. Preferably, the endless loop extends entirely along and underneath the cable on which the slide member is supported.

It is common for a shade structure to be wider than the width of flexible cover which can be purchased.

For this reason, it is known to have a number of flexible covers spaced in a parallel side-by-side relationship to allow the shade structure to extend across widths much larger than the individual width of a flexible cover.

According to the system of the invention, it is preferred that the side-by-side flexible covers are not attached together, so that each cover can be individually extended or retracted.

20 Thus, it is typical for the system to have a number of slide members, with the slide members operating the different flexible covers. A number of the slide members may be attached to the same cable but at spaced apart locations. A single endless loop line member may 25 be provided below the cable with the number of slide members attached to the single endless loop line member such that the line member can advance or retract all the slide members on the single cable.

By having this multiple slide member arrangement, and by having separate but adjacent flexible covers, it is possible to open or close the flexible covers more quickly and efficiently and with less power than would be the case if all the cover members were attached together and a single slide member was required to haul the cover member entirely across the framework.

In order to allow the system to use fairly light duty motors to operate the slide members, it is preferred that the slide members are not all operated at the same time. It is found that the greatest demand on a drive motor is the power required when the flexible cover is coming up to its fully extended position. Thus, it is preferred that the slide members can be moved in a sequential manner as opposed to all at once. To achieve this, the line member may sequentially engage the slide members and this can be achieved by having abutments on the line member which sequentially engage with the slide members such that only one, or possibly only a few slide members, are moved together from a rest position.

As the slide members may be moved in both directions along the cable, one option is to have abutments on each side of the slide member. However, such an arrangement can be simplified by allowing a single abutment which can move to each side of the slide member. This can be achieved by providing the slide member with means to releasably engage with the abutment, and this can be in the form of a resilient means such as a compression cylinder.

S 20 An embodiment of the invention will be described with reference to the following drawings in which Figure 1 is a plan view of a framework covering plants; Figure 2 is a side view of a system for extending and retracting a flexible cover over the framework and where the system is in the retracted position; Figure 3 is the view of Figure 2 where the system is in the extended position; Figure 4 is a close-up view of a slide member according to an embodiment of the invention.

Figures 5 and 6 illustrate variations of the invention.

Referring to the embodiment, and initially to Figure 1, there is shown in plan a framework system 10 to cover rows of trees 11A, 11B. The framework system consists of an array of parallel spaced apart north south cables (for instance 12) and an array of east west cables (for instance 13). The north south cables can be spaced apart by 3 metres or so, while the east west cables can be spaced apart by 10 metres or so. It should be appreciated that the particular spacing of the framework system can vary to suit. The cables are spliced together to form a strong array. The cables are spaced above the ground surface by a number of vertical posts comprising end posts (for example 14) and intermediate posts (for example 15). The height, type and thickness of the posts may vary to suit but for covering trees, the posts are typically up to 6 metres long. The various end posts are stabilised by guy cables (for instance 16), and this entire arrangement is known.

In conventional systems, a fabric is winched over the top of the cable array, but this requires heavy duty winching motors, and it is difficult, if not impossible, to properly tension the fabric. Uneven tensioning causes uneven shade levels and excessive 20 abrasion of the fabric.

According to the invention, the framework system as illustrated in Figure 1 supports three lengths of fabric 17, 18, 19. Each length of fabric is 10 metres wide and can be of any convenient length. The three 25 lengths of fabric are not attached to each other such that each can be separately opened and closed in the north, south direction. One longitudinal end of each length of fabric is secured to a fixed east west extending cable 20A-C. Thus, fabric length 19 has its longitudinal edge attached to cable 20A, fabric length 18 has its longitudinal edge attached to cable 20B and fabric length 17 has its longitudinal edge attached to cable 20C. Cables 20A 20C are spliced to, and firmly attached to the north south cables such that the cables are fixed in position and do not move.

The framework system 10 has peripheral east west poles which are 10 metres apart (this being for convenience only), and these poles include those numbered as 21A 21C. These poles are made from steel and support major north south cables 22A 22C. Major north south cable 22A is also illustrated in Figures 2 4.

Between each major cables 22A 22C are a pair of minor north south cables (see for instance 23A, 23B) which are in the same plane as the major cables but are not attached directly to the an end post, these minor cables being attached to an end east west cable.

In the embodiment, each major north south cables 22A, 22B supports three slide members, it being appreciated that the number of major cables and the number of slide members may vary depending on the size of the framework system. Figures 2 4 show, in side elevation, one end post 21A, and two slide members positioned on major north south cable 22A.

Figure 2 illustrates an upright steel post 21A, on top of which is fitted a steel sleeve 24. To steel sleeve is fitted a vertical pulley 25 having a horizontal axis of rotation. Around pulley 25 is located an endless 20 line member 26 which in the embodiment is a steel cable, with line member 26 extending entirely across the framework system from post 21A to the other post 27A illustrated in Figure 1. Line member 26 is positioned immediately below major cable 22A. In Figure 1, each end 25 post 21A, 21B has an arrangement shown in Figure 2 including a pulley 25, a steel sleeve 24, and an endless loop line member 26. Attached to and slidable along line member 22A are two slide members 28, 29. Figure 4 shows slide member 28 in greater detail. Each slide member has a main body portion 30A, 30B formed with a central bore through which the cable can pass, thereby slidingly attaching the slide members to the cable 22A (see Figure In the main body portion of each slide member is a vice arrangement 31 which has saw-tooth spring-loaded jaws facing backwards (not shown) to enable the slide member to slide along the cable in one direction, but where the vice arrangement will prevent the slide member from sliding in the opposite direction.

8 Above the main body portion of each slide member is an upwardly extending member in the form of a hooked rod 32A, 32B. Hooked rod 32A,B is rigidly connected to an upper portion of the main body portion.

An upper part of the hooked rod has a ring member attached to it 33A, 33B which is slidingly attached to a top rope 34. Each end post 21A, 21B has a top rope attached to it which extends entirely across the framework system and vertically above the main north south cable 22A 22C. The top rope is approximately 300 mm above its respective cable 22A 22C. Top rope 34 is not load bearing and therefore does not need to be formed from steel cable and can be formed from rope.

Flexible covers, such as a shade or hail fabric 19, 18 are attached to each hooked rod. One longitudinal edge of cover 18, 19 is attached to a respective east west cable 20A 20C while the other longitudinal edge of the cover is attached to a respective hooked rod 32A, 32B. For instance, as illustrated in Figures 2 and 3, 20 cover 19 has one longitudinal edge attached to east west cable 20A, while the other longitudinal edge is attached to hooked rod 32A. As the cover can be quite long (up to metres, 100 metres, or even longer), the other longitudinal edge of the cover is secured to a fabric cable 36 (see Figure the fabric cable running in an -east west direction and being slightly above the north south and east west cables forming the framework system.

Fabric cable 36 runs entirely along the longitudinal edge of the fabric, such that in Figure 1, fabric cable 36 extends from the left-hand side of the framework arrangement to the right-hand side of the framework arrangement.

It can therefore be seen that a particular cover (for instance cover 19 in Figure has one fabric cable 36, which is attached to two slide members, one slide member being on cable 22A, the second slide member being on cable 22B. In a similar fashion, cover 18 (see Figure 1) has one longitudinal edge attached to east west cable 20B, and the other longitudinal edge attached to a second fabric cable (not shown) which is again attached to two slide members, one of which is illustrated as 32B in Figure 2.

The slide members slidingly attached to each major north south cable are pulled along the cable by endless loop line member 26 which is guided by pulleys Line member 26 has abutments attached thereto, the abutments being in the form of spheres 37A, 37B. Spheres 37A, 37B are fixed to the line member and are not slidably moveable relative to the line member.

The main body portion of each slide member has a means to allow the spheres to selectively engage with the respective slide member. In the embodiment, this is achieved by having a compression cylinder 38A, 38B on each slide member. The compression cylinder has a central bore through which the line member 26 can pass.

The bore is formed from resilient material such that the bore will initially prevent a sphere 37A, 37B from 20 passing through the bore. However, with greater force, the sphere can be forced through the resilient bore of the compression cylinder.

To extend the fabric covers over the framework system, the slide members are initially in the fully retracted position which is shown generally in Figure 2 :h and where the covers 19, 18 are bundled together adjacent their respective east west cable 20A 20C. In this arrangement, most of the framework system is not covered and light can pass through. To extend the covers over the framework system, and initially referring to Figure 4, the endless loop line member 26 is moved in the direction of the arrow which will cause sphere 37A to move against one end of compression cylinder 38A. When this occurs, further movement of line member 26 in the direction of arrow will cause slide member 28 to slide along its major cable 22A. This in turn will cause cover 19 (but not cover 18) to extend along the framework system in a north south direction. Slide member 28 will continue to slide along its cable 22A until the slide member abuts against an east west cable 20B. This east west cable is also the attachment point of the longitudinal edge of the second cover 18. When slide member 28 abuts against east west cable 20B, it can move no further. However, endless loop line member 26 is continued to be moved in the direction of the arrow which in turn will now force sphere 37A through the compression cylinder and to the other side of the compression cylinder (this position being illustrated in Figure 2).

At this position, fabric length 19 is fully extended between its attachment to east west cable 20A, and its attachment to hooked rod 35A. Also, the fabric is tensioned to be taut, and is also slightly inclined.

By having rod 32A in a forwardly hooked configuration as illustrated in Figure 4, the first cover 19 slightly overlaps the second cover 18 which prevents from occurring between the fabric lengths. The *.overlap can be approximately 1.2 metres. Vice 20 arrangement 31 prevents the taut cover 19 from pulling slide member 28 back along its cable 22A because of the tension in the cover.

Spheres 37A and 37B (see Figure 2) are fixed on line member 26 at particular positions to ensure that the 25 slide members 28, 29 do not all move at once. By having the slide members progressively being moved from a rest position, the demand on the drive motor is considerably less providing cost savings and increased reliability.

In the embodiment, the spheres are fixed to line member 26 such that slide member 28 is initially moved from a rest position by having sphere 37A abutting against compression cylinder 38, while sphere 37B has not yet contacted the compression cylinder on slide member 29.

Only when slide member 28 is moving along its cable 22A does sphere 37B abut against the compression cylinder of slide member 29 to cause slide member 29 to now move along the same cable 22A. Although Figure 2 illustrates only two slide members, it should be appreciated from Figure 1 that there are three (or even more) slide members on cable 22A, the third slide member functioning to extend or retract cover 17.

When the three covers 17 19 have been fully extended and made taut, at that stage each of the spheres has been pulled through the respective compression cylinder and is now on the other side of the compression cylinder. The line member can then be reversed in direction which will now cause each of the slide members to move in the other direction which in turn will cause the respective covers to be retracted. The hooked rod 32A, 32B functions to collect the fabric lengths and to ensure that the fabric lengths are properly pulled back to the retracted position.

Before the slide members can reverse direction, the vice arrangement on each slide member must be released and this can be achieved by a vice lever 40A 40B, a vice lever being positioned on each slide member.

The vice lever is operated by a release line 41 which can .20 be pulled to release the vice arrangement on each slide member thereby allowing the slide members to move backwards. The slide members will continue to move backwards until they strike an east west cable after which continued movement of line member will force the 25 spheres back through the compression cylinders. The spheres are now in a position to allow the slide members to be again extended. For instance, referring to Figure 1, slide member 29 moves backwardly until it strikes its east west cable 20B which is the cable to which one side of cover 18 is attached.

As each fabric length is only about 10 metres wide, each slide member only needs to move about 9 metres. The spheres are thus attached to the line member 26 at approximately 10 metre apart distances. For this reason, it is not necessary for line member 26 to move entirely around pulley 25. Indeed, only about 10 metres of line moves around pulley As each end post 21A 21C has a pulley, and an endless line member, it is advantageous to have a single drive motor (or winch) to move the line member on each pulley (this does away with the requirement to have three or more winches). To achieve this (and as illustrated in Figures 2 and the line member 26 has an upper cable length 42 and a lower cable length 43. These cable lengths are firmly spliced to line member 26. Upper cable length is attached to an upper horizontally extending pulley 44 and lower cable length 43 is attached to a lower horizontal pulley 45. The horizontal pulleys have a vertical axis of rotation and extend above and below vertically extending pulley 25. Each end post 21A 21C has a respective upper and lower horizontal pulley. The upper horizontal pulleys on each end post are all connected together by a horizontally extending endless loop line member 50 (see Figure and all the *-...lower horizontal pulleys 45 are also inter-connected by a ,horizontally extending endless loop line member 51 (see Figure A corner post 46 (see Figure 1) is provided 20 with a single winch which can rotate upper and lower g* horizontally extending line members in a clockwise or anticlockwise direction. Thus, the corner winch can effectively advance or retract the three slide members on each major north south cable 22A 22C.

S 25 Figures 5 and 6 illustrate variations to the S* invention, and particularly variations in the line member on which the spheres are attached.

Referring initially to Figure 5, there is again shown a slide member 28 which is identical to the slide members described above. Slide member 28 again slides along major cable 22A. The hooked rod configuration in this embodiment is slightly different and hooked rod 52 now terminates in another compression cylinder 53.

Hooked rod 52 is still attached to fabric cable 36 to extend fabric length 19.

The predominant variation in this embodiment is that line member 26 has a lower portion 54 extending below major cable 22A, and an upper portion 55 extending above major cable 22A. Each of these line members are provided with spheres (see for instance 37A on lower line member 54 and sphere 56 on upper line member 55). The spheres function in a manner described above and are pulled through their respective compression cylinders.

This arrangement differs principally in that slide member 28 is pulled one way using one of the compression cylinders, and is pulled the other way using the other compression cylinder. This arrangement can provide a smoother sliding action of slide member 28 along its cable 22A.

Figure 6 illustrates a simpler variation where slide member 28 does itself not have a compression cylinder but instead a single compression cylinder 53 is provided on the end of hooked rod 52.

The line member 55 both in the embodiments illustrated in Figure 5 and Figure 6 may be of an endless loop type such that the return portion is line member 54, although this is not essential and optionally line 20 members 54 and 55 might be separate from each other.

It should be appreciated that many other changes or modifications may be made to the embodiment described. For instance, the framework system as illustrated in Figure 1 is an example only and the number 25 of fabric lengths, and the length and width of each fabric length can vary to suit. The number of slide members can vary.

Claims (14)

1. A system for extending and retracting a flexible cover over a framework, the system comprising a slidable member supported by a portion of the framework and slidable along the portion, the flexible cover being connected to the slide member and means to advance and retract the slide member along the portion, wherein the portion includes a cable.

2. The system of claim 1 wherein the framework comprises an array of cables.

3. The system of claim 2 wherein the slide member includes a bore for slidably receiving said cables.

4. The system of any one of the preceding claims wherein the means to extend and retract the slide member comprises a line member engagable with the slide member.

The system of any one of the preceding claims which includes at least two separate and adjacent covers, each cover being connected to a separate slide member.

6. The system of claim 5 wherein each separate slide member is supported by a single cable.

7. The system of claim 6 wherein each separate S• slide member is engaged with a single line member.

8. The system of claim 7 wherein the slide member o .includes a body and an upwardly extending member and the flexible cover is attached to the upwardly extending member.

9. The system of claim 8 wherein each separate slide member includes means for being sequentially engaged by the line member. 30

10. The system of claim 9 wherein said means for sequential engagement includes an abutment located on the S" line member and means for releasably engaging the abutment located on the slide member.

11. The system of claim 9 wherein the means for releasably engaging the abutment is located on the body of the slide member or on the upwardly extending member.

12. The system of claim 9 wherein the line member 'v includes an upper and a lower portion which slidably receive the upwardly extending member and the body respectively, an abutment is located on the upper and lower portions such that said body and said upwardly extending member each have means for releasably engaging a respective abutment.

13. The system of any one of claims 10 to 12 wherein the means for sequential engagement comprises a compression cylinder.

14. The system of any one of the preceding claims wherein the slide member includes a releasable stop means for preventing retraction. A system for extending and withdrawing a flexible cover over a framework, substantially as hereinbefore described with reference to Figures 1 to 4, Figure 5 or Figure 6. DATED this 27 th day of June 2000 John Harry HALL By his Patent Attorneys CULLEN CO. S