Connector coupling for railings

Abstract

A connector coupling 501 for coupling respective ends of a first and second tubular component of a modular handrail system, comprising: an inner cylinder element 601 and an outer sheath element 602, t

Description

Field of the Invention The present invention relates to a connector configured to join together railing tubes so as to facilitate such as those deployed on ramps and platforms, for example. Background of the Invention Modular demountable ramp systems for access to buildings and the like are well known, where all the components which make up said systems may be readily assembled and disassembled. It is generally important that the assembly and disassembly of said ramp systems is secure, safe and rapid. Typical installations consist of a substantially tubular structure combined with various platforms, ramps and stairs. Such installations may be deployed both indoors and outdoors. An internal ramp, sometimes referred to as an indoor wheelchair ramp, can be achieved with a modular system constructed in this fashion. Similarly, means of access from outside to the inside of a building, for example, can be achieved in exactly the same way. Both can be designed in both straight-through and turning configurations. It is common practice for both indoors and outdoors ramp systems to consist chiefly of access platforms, ramps and stairs mounted within a structure made up of substantially linear linking elements such as metal tubes, struts and the like. Typically said linking elements are joined together by means of connecting devices which enable the creation of continuous runs of handrails, for example. However, a number of problems can be encountered in the installation of said linear elements of these ramp systems. These problems are associated chiefly with the need for rapid, reliable and safe assembly and disassembly of said linear elements. It is an object of the invention to provide a connecting coupling for tubular handrails providing quicker and more secure joints between said handrails. Summary of the Invention According to a first aspect there is provided a connector coupling for coupling respective ends of a first and a second tubular component of a modular handrail system, comprising an inner cylinder element and an outer sheath element, the outer sheath element secured to the inner cylinder element and arranged substantially concentrically around the inner cylinder element to define, at each of a first and a second end of the connector coupling, a gap between the inner cylinder element and the outer sheath element, for slidably receiving an end of a tubular component with an interference fit; in which each of a first and a second end of the inner cylinder element is provided with a plurality of slots, extending in a longitudinal direction of the inner cylinder element, that define a corresponding number of tabs therebetween, the tabs resiliently flexible radially inwardly, and wherein an outer diameter of the inner cylinder element has a general taper at each of the first and the second ends of the inner cylinder element. The gap at each end of the connector coupling, between the inner cylinder element and the outer sheath element, enables each end of the connector coupling to be slidingly fitted onto an end of a tubular component, in particular a handrail tube having a substantially circular tube section, so that the tubular component locates within the gap and is gripped between the inner cylinder element and the outer sheath element. This arrangement enables the end of a handrail tube to be retained within the connector coupling without the requirement for the use of any other fixing, for example a mechanical fastening or adhesive (although optional use of such a fixing would render the joint between the handrail tube and the connector coupling more permanent) while still allowing adjustment or disassembly as required. The feature that an outer diameter of the inner cylinder element has a general taper at each of the first and the second ends of the inner cylinder element facilitates the sliding fit of the connector coupling onto the tubular component. In a preferred example, the inner cylinder element projects, in the longitudinal direction, outwardly from the outer sheath element. This arrangement assists manipulation of the connector coupling relative to a tubular component during joining of the connector coupling and the tubular component together. In a preferred example, each of the first and second ends of the inner cylinder element is provided with a plurality of ribs, extending in the longitudinal direction, that project radially outwardly from an outer surface of the inner cylinder element. The ribs function to contact and apply a local pressure to an inner wall of the tubular component to provide a tight and secure fit between the connector coupling and the tubular component. In an example, at least one rib extends along each tab. In an example, the slots are distributed equidistantly around a circumference of the inner cylinder to define tabs having a common width. In an example, a central rib extends along each of the tabs. In a specific example, each of the first and second ends of the inner cylinder element is provided with six equidistantly spaced slots, which define six tabs having a common width, with a single, central rib extending along each of the tabs. In an example, the connector coupling has a straight longitudinal profile. In an example, the connector coupling has a raked longitudinal profile. In an example, the connector coupling has a right-angled profile. A non-straight longitudinal profile allows a variation in the orientation / gradient / direction of a handrail to be accommodated, for example a change between level and sloping orientations, or a turn around a corner. In an example, the inner cylinder element comprises a plastics material. The plastics material may be nylon. The plastics material may be glass fibre reinforced plastic. The manufacture of the inner cylinder element may utilise an injection moulding process. In an example, the outer sheath element comprises a plastics material. The plastics material may be thermoplastic elastomer. The manufacture of the outer sheath element may utilise an injection moulding process. In an example, the outer sheath element has a material elasticity that is greater than a material elasticity of the inner cylinder element. The elasticity of the outer sheath element is such that it contributes to secure gripping of a tubular component following its location within the gap between the inner cylinder element and the outer sheath element of the connector coupling and the retention of the tubular component in position. In an example, a surface of the outer sheath element comprises a textured finish. This feature is functional to improve grip of the connector coupling on a tubular component. In an example, the inner cylinder element is formed from combined first and second cylinder element subcomponents. The inner cylinder element may thus be formed as a unitary component or from a combination of subcomponents. In an example, the outer sheath element is secured to the inner cylinder element such that rotation and / or axial movement of the outer sheath element relative to the inner cylinder element is prevented. According to a second aspect there is provided a method of manufacturing the connector coupling of the first aspect, in which each of the inner cylinder element and the outer sheath element comprises a plastics material, and in which the outer sheath element is secured to the inner cylinder element by over moulding or by two shot moulding. According to a third aspect there is provided a modular demountable ramp system, comprising: at least one walkway component, a plurality of tubular handrail components, and a plurality of connector couplings, each connector coupling of said plurality of connector couplings being a coupling connector according to the first aspect. In an example, the tubular handrail components have a substantially circular tube section. In an example, each of the tubular handrail component comprises a metal material. The tubular handrail components may be manufactured from steel tubes, which may be electrical resistance welded tubes. In an example, the at least one walkway component comprises a platform and a ramp. Particular, and preferred, aspects of the invention are set out in the accompanying claims. Brief Description of the Figures The invention will now be described by way of example only, with reference to the accompanying drawings, in which: Figure I shows a typical ramp installation including tubular handrails and connecting couplings; Figure 2 shows a tubular handrail as seen in Figure I ; Figure 3 shows a tubular handrail in a first alternative condition; Figure 4 shows a tubular handrail in a second alternative condition; Figure 5 shows a first embodiment of a connector coupling for handrails; Figure 6 shows a perspective view of the connector coupling seen in Figure 5; Figure 7 shows a side elevation and cross section of the connector coupling seen in Figures 5 and 6; Figure 8 shows an end elevation of the connector coupling seen in Figures 5 to 7; Figure 9 shows a longitudinal section of the connector coupling seen in Figures 5 to 8; Figure 10 shows a local section of the assembly of the connector coupling seen in Figures 5 to 9 into a tubular handrail; Figure I I shows a second embodiment of a connector coupling for tubular handrails; Figure 12 shows a perspective view of the connector coupling seen in Figure 11; Figure 13 shows a plan view of the connector coupling seen in Figures I I and 12; Figure 14 shows an end elevation of the connector coupling seen in Figures I I to 13; Figure 15 shows a longitudinal section of the connector coupling seen in Figures I I to 14, Figure 16 shows a third embodiment of a connector coupling for tubular handrails; Figure 17 shows a perspective view of the connector coupling seen in Figure 16; Figure 18 shows an end elevation of the connector coupling seen in Figures 16 and 17; Figure 19 shows a side elevation of the connector coupling seen in Figures 16 to 18; and Figure 20 shows a lateral section of the connector coupling seen in Figures 16 to 19. Detailed Description Illustrative embodiments and examples are described below in sufficient detail to enable those of ordinary skill in the art to embody and implement the apparatus described herein. It is to be understood that embodiments and examples can be provided in many alternate forms and the invention should not be construed as limited to the embodiments and examples set forth herein but by the scope of the appended claims. Unless otherwise defined, all terms (including technical and scientific terms) used herein are to be interpreted as is customary in the art. In addition, features referred to herein in the singular can number one or more, unless the context clearly indicates otherwise. Similarly, the terms “comprises”, “comprising”, “includes”, “including”, “has” and / or “having” when used herein, specify the presence of the stated feature or features and do not preclude the presence or addition of one or more other features, unless the context clearly indicates otherwise. In the following description, all orientational terms, such as upper, lower, radially and axially, are used in relation to the drawings and should not be interpreted as limiting on the invention, unless the context clearly indicates otherwise. The drawings are not necessarily drawn to scale, and in some instances the drawings may have been exaggerated or simplified for illustrative purposes only. Disclosed herein is a connector coupling for coupling respective ends of a first and a second tubular component of a modular handrail system, in particular handrail tubes, or those of a modular demountable ramp system, having a substantially circular tube section. The connector coupling comprises an inner cylinder element and an outer sheath element. The outer sheath element is secured to the inner cylinder element and arranged substantially concentrically around the inner cylinder element. At each of first and second ends of the connector coupling a gap is defined between the inner cylinder element and the outer sheath element, in which an end of a tubular component is locatable. Each of first and second ends of the inner cylinder element is provided with a plurality of slots, extending in a longitudinal direction of the inner cylinder element, the slots defining between them a corresponding number of tabs. The tabs are resiliently flexible radially inwardly. Each end of the connector coupling is configured to slidably receive an end of a tubular component, within the gap between the inner cylinder element and the outer sheath element, with an interference fit. A tubular component located within the gap is gripped between inner cylinder element and the outer sheath element, which retains the tubular component in position. The tabs facilitate the sliding engagement of the connector coupling and the end of the handrail tube. Preferably, the ends of the inner cylinder element have a general taper on the outer diameter for facilitating the sliding fit of the connector coupling onto the handrail tube. Preferably, the inner cylinder element projects, longitudinally, outwardly from the outer sheath element for assisting manipulation of the connector coupling relative to the handrail tube as they are joined together. Preferably, each of the first and second ends of the inner cylinder element is provided with a plurality of ribs, extending in the longitudinal direction, that project radially outwardly from an outer surface of the inner cylinder element, for contacting and applying a local pressure to an inside wall of the handrail tube for providing a tight and secure fit between the connector coupling and the handrail tube. The connector coupling may have a straight longitudinal profile or alternatively a non-straight longitudinal profile, which may be a raked or a right-angled profile. Also disclosed herein is a modular demountable ramp system that comprises at least one walkway component, a plurality of tubular handrail components, and a plurality of the connector couplings. Typically, the tubular handrail components have a substantially circular tube section and comprise a metal material. The at least one walkway component may comprise a platform and a ramp. Specific examples will now be described with reference to the accompanying Figures. A modular demountable ramp system 101 is shown in Figure I adjacent to a doorway in a building 102. Such ramp systems are commonly deployed to enable access to and from buildings for example on both a temporary and permanent basis. In the present embodiment the demountable ramp system 101 consists of a series of components including a platform 103 and a ramp 104 to make up a walkway base. In order to provide safe access said walkway base is framed by a balustrade 105 being made up of a number of components including handrail tubes 106. Preferably the walkway bases and balustrades including handrails are bolted together in modules. A first important consideration in the deployment of demountable ramp systems is speed of assembly. A second important consideration in the deployment of said ramp systems is lightness of weight. Additional costs arise from long stays on site as well as carriage of heavy materials to site. Accordingly the demountable ramp system 101 shown is designed for rapid assembly from a set of components having minimal weight. A number of different types of rails and tubes are widely used in demountable ramp systems. In the present embodiment the demountable ramp system 101 employs an array of handrails 106 which help satisfy the need for rapid assembly and lightness of weight. Preferably, the handrails 106 are manufactured from steel tubes. Figure 2 shows a tube of the kind employed in the assembly described in Figure I. In an embodiment said steel tubes are electrical resistance welded tubes otherwise known by the acronym ERW. Preferably said tubes have an internal diameter 201 of 42 millimetres and a relatively thin wall thickness 202 of 1.5 millimetres. The process of manufacturing the tubes involves rolling sheet metal 203 into the final substantially round shape and joining with said welding 204. An advantage of this design is a tube 106 with a relatively high strength to weight ratio. Accordingly the cost of transportation is correspondingly affected and the tubes are furthermore quicker and easier to handle and install by the fitters on site. There are however a number of problems associated with using said lightweight tubes on site. A first disadvantage of the present tube is described in Figure 3. A handrail tube is shown 106 in cross section showing the internal diameter 201. As has already been described the sheet material used to manufacture the tube forms a substantially circular profile when the two faces of said sheet abut at 204. The welding process can generate excessive deposits of metal along this join 301 which have the effect of intruding into the internal diameter 201. This is a problem because said internal diameter needs to be clear of undue distortions and protuberances in order to enable installation as outlined in Figure I. The same problem of excess material within the internal diameter 201 of the tube can occur with deposits left following the process of galvanisation. A second disadvantage relates to effective quality control of said tubes. Handrail tubes 106 may be supplied from different manufacturers and as such may be working to different tolerances. Accordingly the size of internal diameter 201 may vary slightly across different batches for example leading to the problems of installation already described. A further variable is ovality of the tube section where said section may not be a true circle and instead take the form of an ellipse 302, for example. This is a problem because said internal diameter needs to be clear of undue distortions and protuberances in order to enable installation as outlined in Figure I. Figure 4 shows a handrail tube 106 in cross section showing the internal diameter 201. One of the most common instances of damage to said tubes is dents, crushing and other deformation of the free end 401. In addition to the possibility of such damage being caused in the factory in the first instance there is a further likelihood of damage during transit and handling on site. It will by now be appreciated that this is a problem because said internal diameter needs to be clear of undue distortions and protuberances in order to enable installation as outlined in Figure I. Figure 5 shows a first embodiment of a connector coupling 501 for handrail tubes 106. In the present embodiment said connector coupling 501 is located between the two respective ends of handrail tubes 106. In order to make the joint said connector coupling is pushed onto each tube such that the connector coupling is positioned exactly between them. The connector coupling is tight and thus achieves an interference fit between the tubes without the need for additional fixings such as screws or glue, for example. Accordingly a rubber mallet is often used to knock the tubes and connector couplings together. Figure 6 shows an exploded perspective view of the connector coupling 501 assembly with handrail tubes 106 seen in Figure 5. In the present embodiment a connector coupling 501 consists substantially of two elements these being an inner cylinder 601 combined with an outer sheath 602. Said two elements are substantially concentric and therefore define a gap 603 which slides during fitting over the free ends of respective handrail tubes 106. In this way a joint is created between the connector coupling 501 and said adjacent handrail tubes 106. Preferably the inner cylinder 601 is manufactured by a process of injection moulding in a semi rigid plastics material. In the present embodiment said plastics material is nylon such as nylon 6. Preferably said nylon is additionally reinforced with glass fibre to provide extra strength. Located at the free ends of inner cylinder 601 is a plurality of slots 604 which define a corresponding plurality of tabs 605. In the present embodiment said slots 604 and corresponding tabs 605 number six. Preferably the outer sheath 602 is manufactured by a process of injection moulding in a flexible plastics material. In the present embodiment said plastics material is thermoplastic elastomer having the acronym TPE. An advantage of this material is it has properties of elasticity needed for its function similar to those of rubber and yet is capable of being processed like plastics. An object of said elasticity is the outer sheath 602 grips the handrail tubes 106 following their location within the gap 603 and helps retain said tubes in position. A first major benefit of said gripping effect is that there is no need for other fixings or fasteners including adhesives to make the joint. A second major benefit of said gripping effect in preference to said other fixing types is that the assembly shown in Figure I for example is capable of being quickly and easily readjusted or disassembled as required. Figure 7 shows a side elevation and cross section of the connector coupling 501 seen in Figures 5 and 6. The inner cylinder 601 is seen and is substantially enclosed by the outer sheath 602. In the present embodiment the inner cylinder projects outwards somewhat beyond the outer sheet revealing a plurality of slots 604 which define a corresponding plurality of tabs 605 in said cylinder. In the section taken at a position indicated by line 701 a plurality of ribs 702 can also be seen. Figure 8 shows an end elevation of the connector coupling 501 seen in Figures 5 to 7. The inner cylinder 601 is enclosed by the outer sheath 602 with a gap 603 in between. The slots 604, tabs 605 and ribs 702 in the inner cylinder are visible. Figure 9 shows a longitudinal section of the connector coupling 501 seen in Figures 5 to 8. In the present embodiment as has been explained the inner cylinder 601 is manufactured by a process of injection moulding in glass reinforced nylon. The outer sheath 602 is manufactured by a process of injection moulding in a flexible plastics material preferably thermoplastic elastomer having the acronym TPE. The two respective moulded components are joined together by means of over moulding of said sheath over said inner cylinder, or alternatively by the process of two shot moulding. An advantage of both said moulding techniques is the absence of a need for additional fixings, glue or any other means of attachment of the inner cylinder 601 to the outer sheath 602. In the present embodiment a slot 901 is included which reduces the amount of plastic material needed to fill the middle part of the inner cylinder 601. Figure 10 shows a close-up view of the assembly of the connector coupling 501 seen in Figures 5 to 9 into a tubular handrail 106. The view is in longitudinal section and shows the connector coupling 501 positioned adjacent to the handrail tube 106 ready for assembly. The connector coupling 501 is being offered to said handrail 106 in the direction of arrow 1001. The tube wall 202 engages with a gap 603 in the connector coupling thus creating the joint. Ribs located on the inner cylinder 601 such as shown at 702 locate against the inner diameter of the handrail tube wall 202 and apply local pressure to enable a tight and secure fit. Such ribs 702 are sometimes known as crush ribs for this reason. A problem may occur however during the assembly described above of the connector coupling 501 into the tubular handrail 106. The free end of the inner cylinder 601 has a wall 1002 which is substantially square in profile and at right angles to the direction of travel indicated by arrow 1001. When said square coupling profile is introduced into tubular handrail 106 the tube wall 202 also being cut square in profile can catch and foul where the fit is tight. A solution to this problem is therefore provided by means of a plurality of tabs 605. Preferably the tabs are evenly spaced around the circumference of inner cylinder 601. In the present embodiment said tabs number six. Each tab is created by the introduction of a slot 604 either side of it around the circumference of inner cylinder 601. In the present embodiment said tabs accordingly number six. When the connector coupling 501 is introduced into the handrail 106 in the direction of arrow 1001 the tabs 605 are inclined to flex inwards in the direction of arrows 1003 and 1004 as indicated by dashed line 1005 thus permitting unimpeded fitting of the tube wall 202 into the coupling gap 603. A further aid to said unimpeded fitting of the tube wall 202 is the provision of a general taper on the outer diameter of the free end of inner cylinder 601. Preferably said taper is in the region of three degrees as indicated by arrows 1006 and 1007. This taper has the effect of reducing the thickness of cylinder wall 1002 at its free end thus further assisting the sliding fit of connector coupling 501 into the tubular handrail 105. The outer sheath 602 grips the outer diameter of the tube wall 202 as a result of said sheath having properties of elasticity as already mentioned. The sheath has a relatively thin wall which has the benefit of only a small increase in overall diameter of connector coupling 501 where this meets the tubular handrail 105. Thus in the case of an installation such as is shown in Figure I extended runs of handrails present minimal interruption to hands holding onto said rails for example. It has already been explained how outer sheath 602 is moulded from a flexible plastics material such as thermoplastic elastomer. A first additional benefit from using this process is the overall surface may be provided with a textured finish so as to improve grip of connector coupling 501. A second additional benefit from using this process is it is possible to mould in logos and other graphic devices into the material without the need for a separate process to achieve said logo, for example. Figure I I shows a second embodiment of a connector coupling 1101 for tubular handrails 106. In the present embodiment said connector coupling 1101 is located between the two respective ends of handrail tubes 106 in a similar fashion to that already described in the case of the first embodiment 501 shown in Figure 5. It will be noted however that connector coupling 1101 has a raked longitudinal profile as opposed to a straight longitudinal profile. In Figure I a platform and ramp are shown for example where the orientation of the handrails 106 changes accordingly from level to downhill and connector coupling 1101 is suitably configured to enable this change in orientation. In the present embodiment the angle of said change in orientation is four degrees from the horizonal where shown I 102. The reason for this particular angle relates to part M of the UK Building Regulations concerning approved gradients for access to different categories of buildings. In the present embodiment said connector coupling 1101 is intended to satisfy commercial rather than residential applications where said commercial applications call for a relatively shallow gradient of 1:15 which equivalates to 3.7 degrees or 1:20 which equivalates to 2.8 degrees. This may be contrasted with residential applications which call for a sightly steeper gradient of 1:12 which equivalates to five degrees. It should be noted that on site a variation of around one degree is deemed insignificant and presents no problems during installation. Figure 12 shows a perspective view of the connector coupling 1101 seen in Figure 11. As in the case of the first embodiment 501 shown in Figure 6 a connector coupling 1101 consists substantially of two elements these being an inner cylinder 1201 combined with an outer sheath 1202. Said two elements are substantially concentric and therefore define a gap 1203 which slides during fitting over the free ends of respective handrail tubes 106. Preferably the inner cylinder 1201 is manufactured by a process of injection moulding in a semi rigid plastics material. In the present embodiment said plastics material is nylon such as nylon 6. Preferably said nylon is additionally reinforced with glass fibre to provide extra strength. Located at the free ends of inner cylinder 1201 is a plurality of slots 1204 which define a corresponding plurality of tabs 1205. In the present embodiment said slots 1204 and corresponding tabs 1205 number six. Preferably the outer sheath 1202 is manufactured by a process of injection moulding in a flexible plastics material. In the present embodiment said plastics material is thermoplastic elastomer. Figure 13 shows a plan view of the connector coupling 1101 seen in Figures I I and 12. As in the case of the first embodiment 501 shown in Figure 6 the inner cylinder 1201 is seen and is substantially enclosed by the outer sheath 1202. In the present embodiment the inner cylinder projects outwards somewhat beyond the outer sheet revealing a plurality of slots 1204 which define a corresponding plurality of tabs 1205 in said cylinder. Figure 14 shows an end elevation of the connector coupling 1101 seen in Figures 11 to I 3. The inner cylinder 1201 is enclosed by the outer sheath 1202 with a gap 1203 in between. The slots 1204 and tabs 1205 in the inner cylinder are visible. Ribs 1401 located on the inner cylinder 1201 locate against the inner diameter of the handrail tube wall and apply local pressure to enable a tight and secure fit Figure 15 shows a longitudinal section of the connector coupling 1101 seen in Figures I I to 14. In the present embodiment the angle of said change in orientation is four degrees from the horizonal where shown I 102. Ribs 1401 are seen on the inner cylinder 1201. As in the case of the first embodiment 501 shown in Figure 6 and as has been explained the inner cylinder 1201 is manufactured by a process of injection moulding in glass reinforced nylon. The outer sheath 1202 is manufactured by a process of injection moulding in a flexible plastics material preferably thermoplastic elastomer having the acronym TPE. The two respective moulded components are joined together by means of over moulding of said sheath over said inner cylinder, or alternatively by the process of two shot moulding. The assembly of connector coupling 1101 seen in Figures I I to 15 into a tubular handrail 106 has already been explained and is identical to that described in Figure 10. Figure 16 shows a third embodiment of a connector coupling 1601 for tubular handrails. As in the case of the first embodiment 501 shown in Figure 6 said connector coupling 1601 is located between the two respective ends of handrail tubes 106 in a similar fashion to that already described in the case of the first embodiment 501 shown in Figure 5 and also the second embodiment 501 shown in Figure II. It will be noted however that connector coupling 1601 has a substantially right angled profile. In Figure I a platform and ramp are shown for example where the plan layout of the handrails 106 changes through ninety degrees and connector coupling 1601 is suitably configured to enable this change in orientation. Figure 17 shows a perspective view of the connector coupling 1601 seen in Figure 16. As in the case of the first embodiment 501 shown in Figure 6 and the second embodiment shown in Figure 12 a connector coupling 1601 consists substantially of two elements these being a pair of inner cylinders 1701 and 1702 at right angles to each other combined with an outer sheath 1703. Said two elements are substantially concentric and therefore define a gap 1704 which slides during fitting over the free ends of respective handrail tubes 106. Ribs 1707 located on the inner cylinders 1701 and 1702 respectively locate against the inner diameter of the handrail tube wall and apply local pressure to enable a tight and secure fit. Preferably the inner cylinder 1601 is manufactured by a process of injection moulding in a semi rigid plastics material. In the present embodiment said plastics material is nylon such as nylon 6. Preferably said nylon is additionally reinforced with glass fibre to provide extra strength. Located at the free ends of inner cylinder 1701 is a plurality of slots 1705 which define a corresponding plurality of tabs 1706. In the present embodiment said slots 1705 and corresponding tabs 1706 number six. Preferably the outer sheath 1703 is manufactured by a process of injection moulding in a flexible plastics material. In the present embodiment said plastics material is thermoplastic elastomer. Figure 18 shows a first elevation of the connector coupling 1601 seen in Figures 16 and I 7. As in the case of the first embodiment 501 shown in Figure 6 a combined first cylinder 1701 and second cylinder 1702 are substantially enclosed by the outer sheath 1703. In the present embodiment the inner cylinders project outwards somewhat beyond the outer sheath 1703 revealing a plurality of slots 1705 which define a corresponding plurality of tabs 1706 at the free ends of both cylinders 1701 and 1702. Figure 19 shows a second elevation of the connector coupling 1601 seen in Figures 16 to 18. Combined inner cylinders 1701 and 1702 are enclosed by the outer sheath 1703 with a gap 1704 in between. The slots 1705, tabs 1706 and ribs 1707 in the inner cylinders are visible. Figure 20 shows a lateral section of the connector coupling 1601 seen in Figures 16 to 19. As in the case of the first embodiment 501 shown in Figure 6 and as has been explained combined first cylinder 1701 and second cylinder 1702 are manufactured by a process of injection moulding in glass reinforced nylon. The outer sheath 1703 is manufactured by a process of injection moulding in a flexible plastics material preferably thermoplastic elastomer having the acronym TPE. The two respective moulded components are joined together by means of over moulding of said sheath over said inner cylinder, or alternatively by the process of two shot moulding. The assembly of connector coupling 1601 seen in Figures 16 to 19 into a tubular handrail 106 has already been explained and is similar to that described in Figure 10. It will be appreciated however that fitting a right angle can be more difficult than fitting a substantially linear coupling such as first embodiment 501 or second embodiment 1101. Accordingly in the present embodiment the portion of inner cylinders 1701 and 1702 respectively projecting beyond the limit of outer sheath 1703 differs as indicated by arrows 2001 and 2002 respectively. This arrangement assists manipulation of the coupling 1601 during installation of a right angled configuration of handrails 105 such as is described in the ramp installation 101 in Figure I. The connector coupling described herein advantageously allows tubular components, in particular handrail tubes, to be joined without requiring use of any other fixing, the fit between the connector coupling and each tubular component being tight and secure yet allowing adjustment and disassembly as required. The connector coupling comprises specific features described herein that facilitate initial engagement of the connector coupling and the tubular component and subsequent retention of the tubular component in position. The disclosed connector coupling is relatively strong and lightweight, which is beneficial for transportation and handling. Described herein is a connector coupling for coupling respective ends of first and second tubular components of a modular handrail system comprises an outer sheath element that is secured to, and arranged substantially concentrically around, an inner cylinder element to define, at each of first and second ends of the connector coupling, a gap between the inner cylinder element and the outer sheath element, for slidably receiving an end of a tubular component with an interference fit. Each of first and second ends of the inner cylinder element is provided with a plurality of slots, extending in a longitudinal direction of the inner cylinder element, that define a corresponding number of tabs therebetween that are resiliently flexible radially inwardly. A method of manufacturing the connector coupling is also described herein. Further described herein is a modular demountable ramp system comprising the connector coupling. Although illustrative embodiments and examples of the invention have been disclosed in detail herein, with reference to the accompanying drawings, it is to be understood that the invention is not limited to the precise embodiment and examples shown and / or described and that various changes and modifications can be effected therein by one skilled in the art without departing from the scope of the invention as defined by the appended claims.

Claims

I. A connector coupling for coupling respective ends of a first and a second tubular component of a modular handrail system, comprising:an inner cylinder element and an outer sheath element, the outer sheath element secured to the inner cylinder element and arranged substantially concentrically around the inner cylinder element to define, at each of a first and a second end of the connector coupling, a gap between the inner cylinder element and the outer sheath element, for slidably receiving an end of a tubular component with an interference fit;in which each of a first and a second end of the inner cylinder element is provided with a plurality of slots, extending in a longitudinal direction of the inner cylinder element, that define a corresponding number of tabs therebetween, the tabs resiliently flexible radially inwardly, and wherein an outer diameter of the inner cylinder element has a general taper at each of the first and the second ends of the inner cylinder element.

2. The connector coupling of claim I, wherein the inner cylinder element projects, in the longitudinal direction, outwardly from the outer sheath element.

3. The connector coupling of claim I or claim 2, wherein each of the first and second ends of the inner cylinder element is provided with a plurality of ribs, extending in the longitudinal direction, that project radially outwardly from an outer surface of the inner cylinder element.

4. The connector coupling of any one of claims I to 3, wherein the connector coupling has a straight longitudinal profile.

5. The connector coupling of any one of claims I to 3, wherein the connector coupling has a raked longitudinal profile.

6. The connector coupling of any one of claims I to 3, wherein the connector coupling has a right-angled profile.

7. The connector coupling of any one of claims I to 6, wherein the inner cylinder element comprises a plastics material.

8. The connector coupling of any one of claims I to 7, wherein the outer sheath element comprises a plastics material.

9. The connector coupling of claims 7 and 8, wherein the outer sheath element has a material elasticity that is greater than a material elasticity of the inner cylinder element.

10. The connector coupling of claim 8 or claim 9, wherein a surface of the outer sheath element comprises a textured finish.I I. The connector coupling of any one of claims I to 10, wherein the inner cylinder element is formed from combined first and second cylinder element subcomponents.

12. A method of manufacturing the connector coupling of claims 7 and 8, in which the outer sheath element is secured to the inner cylinder element by one of: over moulding, two shot moulding.

13. A modular demountable ramp system, comprising: at least one walkway component, a plurality of tubular handrail components, anda plurality of connector couplings, each connector coupling of said plurality of connector couplings being a coupling connector according to any one of claims I to I I.

14. The modular demountable ramp system of claim 13, wherein each tubular handrail component of said plurality of tubular handrail components comprises a metal material.

Images