WO2018039733A1

WO2018039733A1 - Joint and edge profile for applied surfacing in playgrounds

Info

Publication number: WO2018039733A1
Application number: PCT/AU2017/050940
Authority: WO
Inventors: Graham Kevin Brown
Original assignee: Combitile Pty Ltd
Priority date: 2016-09-02
Filing date: 2017-09-01
Publication date: 2018-03-08
Also published as: AU2017320352A1

Abstract

An edge or joint strip for polymer soft fall covering is described. The joint or edge strip consists of an elongate flange formed from a plastics material and a boundary member projecting substantially perpendicular from the elongate flange. A plurality of shrinkage prevention tabs are spaced transversely from the boundary member relative to a longitudinal axis of the elongate flange and project substantially perpendicular to the elongate flange. In use the shrinkage prevention tabs provide a mechanical resistance to prevent local shrinkage of a soft fall polymer during curing.

Description

TITLE

JOINT AND EDGE PROFILE FOR APPLIED SURFACING IN PLAYGROUNDS

FIELD OF THE INVENTION [001 ] The present invention relates to the field of safety, in particular in playgrounds. More particularly, the invention relates to a joint and edging material for playground soft fall.

BACKGROUND TO THE INVENTION [002] The invention relates to edge or joint strips useful for poured-in-place playground surfacing applications. At present applicators commonly form a key joint when changing colours or finishing installations temporarily. This method, while effective, is slow and inaccurate when following complex shapes and multicoloured patterns. Most applications of poured-in-place surfacing contract as they cure and unless precautions are made will leave a distinct gap between the old and the new surface. The invention is an extruded or moulded PVC or similar plastics material edge or joint strip which allows accurate and pre-determined shapes and greatly reduces the chance of shrinkage at the edge or joint.

[003] Over the last several years the nature of material used in playgrounds and similar locations has changed. It has been realised that playgrounds, paths, pool surrounds and similar locations are prone to a risk of injury due to falls, slips and trips. Whereas it was once common for a playground to be built over sand it is now accepted that sand is not an adequately safe material. Sand gave way to bark as a preferred soft fall material but current standards require at least 30cm and preferably 40cm of material. Apart from the cost of providing large volumes of bark for soft fall (or sand), the difficulty of maintaining an even cover has led to a realisation that better materials are required.

[004] More recently the former materials of sand and bark have given way to various polymer materials. There are a variety of materials available for use as

Substitute Sheet

(Rule 26) RO/AU soft fall. One material is ethylene propylene diene monomer (EPDM) and another material is coloured styrene butadiene rubber (CSBR). These are merely indicative materials and other polymer materials are known for soft fall applications. [005] One problem with these polymer materials is that they are prone to a degree of shrinkage during curing. This is not necessarily a problem if a homogeneous surface is applied since the material shrinks away at the edges but does not impact the effectiveness of the soft fall in the working area. However, more recently, efforts to produce aesthetically pleasing appearances have let to non-homogeneous soft fall coverings. For instance, various patterns are worked into the soft fall to display pictures, like dolphins or ponies. A problem arises because the shrinkage leads to gaps appearing at the joints between the background and the images.

[006] A further problem occurs if repair of a soft fall covering is required. Typically a damage area will be cut and removed, then replaced with new polymer material. When the new material cures it shrinks leaving a gap at the join. One solution has been to pre-cure the soft fall material then cut it to fit in the space caused by removal of the damaged material. This can be an effective solution but is very labour intensive. Furthermore, in order to ensure a good fit, it is generally considered necessary to key the sections together, like a jigsaw. This adds to the time and effort required as well as impacting the aesthetic of any pattern formed in the soft fall.

[007] Because of the problems with cutting and fitting pre-cured soft fall the more common solution is to use a cure-in-place material but provide a degree of overlap to allow for shrinkage. Although good in theory it has proven to be difficult to achieve the desired outcome in practice. To date there has not been an effective solution for repair of polymer soft fall nor an effective way of dealing with shrinkage during curing of polymer soft fall coverings.

[008] Although the above discussion has been made in respect of a horizontal soft fall surface, it will be appreciated that there are also applications for vertical surfaces. For instance, more adventurous playgrounds have led to a need to provide protection against injury due to side impact. The same issues arise when applying soft fall to vertical surfaces as have been discussed above for horizontal surfaces.

SUMMARY OF THE INVENTION

[009] In one form, although it need not be the only or indeed the broadest form, the invention resides in an edge or joint strip for polymer soft fall covering comprising:

an elongate flange formed from a plastics material;

a boundary member projecting substantially perpendicular from the elongate flange;

a plurality of shrinkage prevention tabs spaced transversely from the boundary member relative to a longitudinal axis of the elongate flange and projecting substantially perpendicular to the elongate flange.

[0010] In one form the edge or joint strip has shrinkage projection tabs spaced to one side of the boundary member. In another form the edge or joint strip has shrinkage projection tabs spaced to both sides of the boundary member.

[001 1 ] Suitably the plastics material is flexible and can be formed into shapes. The edge or joint strip is preferably extruded.

[0012] The edge or joint strip may further comprise a plurality of cut-outs in the elongate flange to assist with shaping the edge or joint. The cut-outs are suitably tooth-shaped and located between the shrinkage prevention tabs.

[0013] The edge or joint strip may conveniently be affixed to a surface to be covered by screwing or pinning through the flange member adjacent the shrinkage prevention tabs. Alternately, the edge or joint strip may be affixed by glue or double-sided tape.

[0014] The boundary member may be formed from a different material than the elongate flange. The boundary member and elongate flange may be co- extruded. [0015] Further features and advantages of the present invention will become apparent from the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS [0016] To assist in understanding the invention and to enable a person skilled in the art to put the invention into practical effect, preferred embodiments of the invention will be described by way of example only with reference to the accompanying drawings, in which:

[0017] FIG 1 shows a first embodiment of the edge or joint strip configured as an edge strip;

[0018] FIG 2 shows a plan view of the edge strip of FIG 1 ;

[0019] FIG 3 shows an end view of the edge strip of FIG 1 ;

[0020] FIG 4 shows a second embodiment of the edge or joint strip configured as a joint strip; [0021 ] FIG 5 shows a plan view of the joint strip of FIG 4;

[0022] FIG 6 shows an end view of the joint strip of FIG 4;

[0023] FIG 7 shows an end view of the second embodiment of FIG 4 when in use;

[0024] FIG 8 demonstrates fixing of the edge strip of FIG 1 to a vertical surface;

[0025] FIG 9 demonstrates fixing of the joint strip of FIG 4 to a horizontal surface.

DETAILED DESCRIPTION OF THE INVENTION [0026] Embodiments of the present invention reside primarily in an edge or joint strip. Accordingly, the integers have been illustrated in concise schematic form in the drawings, showing only those specific details that are necessary for understanding the embodiments of the present invention, but so as not to obscure the disclosure with excessive detail that will be readily apparent to those of ordinary skill in the art having the benefit of the present description.

[0027] In this specification, adjectives such as first and second, left and right, and the like may be used solely to distinguish one element or action from another element or action without necessarily requiring or implying any actual such relationship or order. Words such as "comprises" or "includes" are intended to define a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed, including elements that are inherent to such a process, method, article, or apparatus.

[0028] Referring to FIG 1 there is a shown a first embodiment of an edge or joint strip configured as an edge strip 10. The edge strip 10 comprises an elongate flange 1 1 and a boundary member 12. The boundary member 12 extends substantially perpendicular from the elongate flange 1 1 . A plurality of shrinkage prevention tabs 13 are spaced along the elongate flange 1 1 . The shrinkage prevention tabs 13 also extend substantially perpendicular from the elongate flange 1 1 but, in the preferred embodiment, may have a slight curve as depicted.

[0029] In use, the boundary member 12 provides a terminal boundary for the soft fall material and the shrinkage prevention tabs 13 provide a mechanical resistance to shrinkage of the soft fall in the vicinity of the boundary member. The operation is described in greater detail below by reference to FIG 5.

[0030] The edge strip 10 is made from a flexible plastics material so that it can be bent to shape as desired. A suitable plastics material is polyvinylchloride (PVC) with adequate plasticizers to provide the desired degree of flexibility. Other polymers, such as polypropylene or high density polyethylene (HDPE) would also be suitable.

[0031 ] To further allow for flexibility, the edge strip 10 may be provided with cut-outs 14 formed in the elongate flange 1 1 between the shrinkage prevention tabs 13. The cut-outs may be tooth-shaped as shown but the invention is not limited to this specific embodiment. The cut-outs 14 are shown most clearly in the plan view of FIG 2 and the shrinkage prevention tabs 13 are shown most clearly in FIG 3.

[0032] Turning now to FIG 4, there is shown a second embodiment of the edge or joint strip in the form of a joint strip 20. Similar to the first embodiment, the joint strip 20 comprises an elongate flange 21 and a boundary member 22. The boundary member 22 extends substantially perpendicular from the elongate flange 21 . A plurality of shrinkage prevention tabs 23 are spaced along the elongate flange 21 . The shrinkage prevention tabs 23 also extend substantially perpendicular from the elongate flange 21 and, as with the first embodiment, may have a slight curve as depicted.

[0033] The joint strip 20 is made from a flexible plastics material so that it can be bent to shape as desired. Suitable plastics material may be polyvinylchloride (PVC), polypropylene or high density polyethylene (HDPE).

[0034] To further allow for flexibility, the joint strip 20 may be provided with cut-outs 24 formed in the elongate flange 21 between the shrinkage prevention tabs 23. The cut-outs may be tooth-shaped as shown but the invention is not limited to this specific embodiment. The cut-outs 24 are shown most clearly in the plan view of FIG 5 and the shrinkage prevention tabs 13 are shown most clearly in FIG 6. [0035] In use, the boundary member 22 provides a boundary between soft fall material on one side and the same or a different soft fall material on the other side. The shrinkage prevention tabs 23 provide a mechanical resistance to shrinkage of the soft fall in the vicinity of the boundary member 22. The operation is described in greater detail below by reference to FIG 7. [0036] In a preferred embodiment the boundary member 22 may be made from a softer plastics material than the elongate flange 21 . This may be desirable so ensure safety at the joint between soft fall materials. It will be appreciated that a hard material could cause an injury risk should a person fall directly against the boundary member 22. This is more of an issue for the joint strip 20 than the edge strip 10 since the joint strip 20 may be employed in the most actively used part of a playground whereas the edge strip will be employed towards a less actively used outer region of the playground.

[0037] Turning now to FIG 7, a depiction of the edge or joint strip in use is provided. For purposes of description FIG 7 shows a joint strip 20, but the principle of operation applies equally to the edge strip 10. In use the elongate flange is fixed to a surface to form a desired shape. This may be a simple curve or a more complex shape such as an image of a dolphin or other child-friendly animal. In the embodiment of FIG 7 the elongate flange 21 is shown attached to a surface 30 with pins or rivets 31 . It is convenient to use pins that are shot into underlying concrete in known manner but other techniques such as screwing, bolting, gluing and taping are also suitable.

[0038] A first soft fall material 32 is poured up to the boundary member 22 so that it covers the shrinkage prevention tab 23a. Similarly, a second soft fall material 33 (perhaps the same material) is poured up to the boundary member 22 so that it covers the shrinkage prevention tab 23b. As the first soft material 32 and the second soft fall material 33 begin to cure there will be a degree of shrinkage. However the shrinkage prevention tabs 23a, 23b provide a

mechanical resistance to shrinkage away from the boundary member 22.

Shrinkage will still occur over the bulk of the soft fall material but there will not be local movement leading to a gap between soft fall material 32 and soft fall material 33.

[0039] Turning now to FIG 8, an edge strip 10 is shown fixed to a wall 40. The edge strip 10 may be fixed to the wall 40 using pins, rivets, bolts, screws, glue or tape as previously described. The edge strip 10 may also be fixed to the ground through the elongate flange 1 1 . As most walls are straight there is most likely not a requirement for cut-outs. The embodiment of FIG 8 is shown fixed with glue.

[0040] Fixing of a joint strip 20 is shown in FIG 9. The joint strip 20 may be fixed to the ground 50 using pins, rivets, bolts, screws, glue or tape as previously described. It will normally be the case that the joint strip 20 will be employed in a non-linear shape so cut-outs may be required. The embodiment of FIG 9 is shown fixed with glue and without cut-outs.

[0041 ] The inventors have found that an appropriate process for producing the edge or joint strip is to extrude the elongate flange, boundary member and shrinkage prevention tabs as a single item and then cut or stamp the cut-outs. In the case where the boundary member is a softer material than the elongate flange the joint strip may be produced by co-extrusion. Although the inventors have determined that extrusion is an appropriate process, it is recognized that moulding is also possible. If the edge or joint strip is moulded the cut-outs will be moulded in in place so cutting or stamping will not be required.

[0042] The edge or joint strip herein described provides an effective solution to the problem of gaps forming in soft fall material due to curing. The shrinkage prevention tabs provide a mechanical resistance to shrinkage near the boundary member, thus substantially eliminating undesirable gaps.

[0043] The above description of various embodiments of the present invention is provided for purposes of description to one of ordinary skill in the related art. It is not intended to be exhaustive or to limit the invention to a single disclosed embodiment. As mentioned above, numerous alternatives and variations to the present invention will be apparent to those skilled in the art of the above teaching. Accordingly, while some alternative embodiments have been discussed specifically, other embodiments will be apparent or relatively easily developed by those of ordinary skill in the art. Accordingly, this invention is intended to embrace all alternatives, modifications and variations of the present invention that have been discussed herein, and other embodiments that fall within the spirit and scope of the above described invention.

Claims

1 . An edge or joint strip for polymer soft fall covering comprising:

an elongate flange formed from a plastics material;

2. The edge or joint strip of claim 1 wherein the edge or joint strip has the shrinkage projection tabs spaced to one side of the boundary member.

3. The edge or joint strip of claim 1 wherein the edge or joint strip has the shrinkage projection tabs spaced on both sides of the boundary member.

4. The edge or joint strip of claim 1 wherein the plastics material is flexible and can be formed into shapes.

5. The edge or joint strip of claim 1 wherein the edge or joint strip is extruded.

6. The edge or joint strip of claim 1 further comprising a plurality of cutouts in the elongate flange to assist with shaping the edge or joint.

7. The edge or joint strip of claim 6 wherein the cut-outs are tooth-shaped and located between the shrinkage prevention tabs.

8. The edge or joint strip of claim 1 wherein the boundary member is formed from a different material than the elongate flange.

9. The edge or joint strip of claim 8 wherein the boundary material is softer than the elongate flange.

10. The edge or joint strip of claim 8 wherein the boundary member and elongate flange are co-extruded.

1 1 . The edge or joint strip of claim 1 wherein the edge or joint strip is affixed to a surface to be covered by screwing or pinning through the flange member adjacent the shrinkage prevention tabs.

12. The edge or joint strip of claim 1 wherein the edge or joint strip is affixed to a surface to be covered by glue or double-sided tape.

13. The edge or joint strip of claim 1 wherein the plurality of shrinkage prevention tabs are spaced along the elongate flange member.