GB2536971A - A coupling device for use in connecting trunking sections - Google Patents

Abstract

A coupling device 50, for use in connecting trunking sections, comprising; a first coupling member 56 for sealing the junction between abutting walls on trunking sections (52, 54 figure 5) and having a couple of apertures 66, 68, extending therein. At least one second coupling member 88, 90, for sealing further junctions between other abutting walls of the trunking sections, having projections 126, 128, for engaging the apertures in the first coupling member and also having at least one retainer 124 for retaining the second coupling member in engagement with the trunking sections. The coupling devices may comprise rubberised seals 70, 104, 106. A second invention discloses a trunking section (130, figure 6), for joining further trunking sections together at angles, comprising an insert (154) attached to a wall (138) with a fixing portion (162) which has extension portions (156, 168). The fixing portion may be connected to the wall by welding.

Description

A Coupling Device for use in Connecting Trunking Sections The present invention relates to a coupling device for use in connecting trunking sections and to trunking sections which use such a coupling device and relates particularly, but not exclusively, to dust and splash resistant easy clean trunking and a coupling a therefor.

The use of trunking is well known for carrying and protecting electrical cables and the like around buildings, particularly in an industrial environment. Where that environment relates to the production of food, drink, pharmaceuticals and the like, the trunking must be corrosion resistant and easy to clean. In such factories trunking made from stainless steel is used and the trunking, and in particular the junctions between the sections of trunking, are formed so as to have as many continuous and smooth surfaces as possible with as few places where dirt can gather and cannot be easily cleaned.

In order to connect two lengths of trunking a coupling is used and in environments where the ingress of water or dust are of concern a coupling with a seal is used. Examples of such dust and splash proof couplings are shown in figures 1 and 2. In the trunking system 10 shown in figure 1, lengths of trunking 12 and 14 are joined together with a coupling 16. The trunking sections 12 and 14 are formed from a sheet of metallic material, typically stainless steel, which is folded to form the linear lengths of trunking. The coupling 16 has an internal supporting structure 18 and an external sealing portion 20. The support structure 18 is also formed from a folded sheet metal material and the sealing portion 20 is a rubberised sealing material such as neoprene. -2 -

The lengths of trunking 12 and 14 are joined together by sliding the coupling 16 into the ends of the trunking sections so that the holes 22 and 24 in the trunking sections are aligned with the holes 26 in the coupling. Bolts (not shown) are then inserted through these aligned holes and fixed with nuts (also not shown).

In order for the sealing portion 20 on the coupling 16 to effectively prevent the ingress of dust and splashed water it needs to provide a close interference fit. As a result, the manufacturing tolerance of the coupling is significant. If the coupling is too small it will not provide sufficient sealing with the trunking sections and this is particularly a problem in the corners. If there is insufficient sealing material in the corners they represent an easy route for water and dust to access the inside of the trunking system 10. However, too much sealing material makes the coupling very difficult to insert into the trunking sections and can result in the edges of the open ends of the trunking sections damaging the sealing material.

An alternative coupling 30 is shown in figure 2 and this generally provides a better seal than the version shown in figure 1. In this example the coupling 30 has the sealing material 32 on the inside of the support structure 34 and as a result the coupling 30 is placed around the outside of the trunking sections 12 and 14. This has the advantage that the locating of the coupling on the trunking is less likely to result in damage to the seal as it can be easily slid around the trunking sections. However, it also has the disadvantage that the number of dirt traps on the external surface of the trunking increases compared to the system shown in figure 1.

It is preferable for trunking systems used in the food, beverage and pharmaceutical preparation industries to use internally mounted threaded fixings such as studs. These studs -3 -are not visible on the outer surfaces of the trunking and therefore provide an external surface which is easy to clean and does not create dirt traps. In the trunking system shown in figure 1 it is possible to replace the coupling 16 with a similar coupling in which the holes 26 have been replaced with slits which extend to the edges of coupling 16 and allow the coupling to be slid over the studs which are located on the inner surface of the trunking where the holes 22 and 24 are presently shown. This coupling has the disadvantage that if the nuts that are used to secure the coupling sufficiently tightened the properly secured together and weight is applied to them.

onto the threaded studs are not trunking sections will not be may become separated if excessive Figure 3 shows a trunking section 36 used for joining further lengths of trunking 14 together. The trunking section 36 has a body portion 38 that forms the external surfaces of the trunking corner section 36. It also includes a built-in coupling which is formed from inserts 38, 40 and 42 which are fixed, typically by welding, to the body portion 38. Although it is convenient to have the coupling formed into the trunking section in order to make this connection dust and/or splash proof the coupling must be lined with a suitable sealing material and the previously described problems of damage to the sealing portion are again experienced. Furthermore, the base of the trunking sections does not contain a coupling portion and therefore no seal is provided in this area. This problem can be overcome by using a modified version of the coupling shown in figure 1 where one end of the coupling is splayed open so as to accommodate the shape of the corner section 36. However, this shape is significantly more complicated to manufacture and still retains many of the problems with damage to the seal experienced with the devices of the prior art shown in figure 1. -4 -

Preferred embodiments of the present invention seek to overcome the above described disadvantages of the prior art.

According to an aspect of the present invention there is provided a coupling device for use in connecting trunking 5 sections, the coupling device comprising:-a first coupling member for substantially sealing a junction between at least one first and at least one second wall on respective first and second trunking sections in use positioned adjacent each other, the first coupling member having at least one first aperture extending therein; and at least one second coupling members for substantially sealing further junctions between further walls of said first and second trunking sections adjacent said first and second walls and having respective projections for engaging said first apertures in said first coupling member and also having at least one first retainer for cooperating with a second retainer associated with said trunking members for retaining the second coupling member in engagement with said trunking sections.

By providing a coupling in two or preferably three parts 20 the advantage is provided that the seal between the coupling and the trunking is significantly improved compared to the prior art and the risk of damage to the seal is almost completely eliminated. The use of the apertures and retainers engaged therein recreates the structural strength of the couplings of the prior art but this rigidity is only created once the coupling is inside the trunking thereby avoiding the potential for damaging the sealing material as it is introduced into the trunking. Furthermore, by using separate parts the sealing around the corners of the trunking is significantly improved as it is easy to provide sufficient sealing material in a suitably deformable material to ensure that the seal extends fully into the corners of the trunking. A further advantage is that the -5 -coupling of the present invention is able to work with studs secured to the inside of the trunking sections without using a coupling with slots cut in. By using holes the trunking sections cannot be pulled apart and are therefore more securely fixed 5 together. Overall the invention allows trunking sections to be coupled together without the use of externally headed screws and with a better seal which is both dust and splash proof. The trunking is therefore secured against water and dust ingress and is easy to clean with no dirt traps beyond the unavoidable 10 junctions between trunking sections.

In a preferred embodiment the first coupling member further comprising a first sealing portion and a first body portion formed from a material having a greater rigidity than said first sealing portion.

In another preferred embodiment the first aperture is formed in said first body portion.

The second coupling member may further comprise a second sealing portion and a second body portion formed from a material having a greater rigidity than said second sealing portions.

In a preferred embodiment the engaging member extends from said second body portion.

In another preferred embodiment at least one of said first and second sealing portions comprise a rubberised material.

In a further preferred embodiment at least one of said 25 first and second body portions comprise a metallic material.

By forming the first and second coupling members from sealing portions and body portions, in particular a rubberised sealing portion and a metal body portion, the advantage is provided that the rigid metal body provides the strength needed to form a secure junction of the trunking sections and the -6 -rubberised sealing portion is sufficiently pliant to create a suitable seal between the coupling and trunking.

The first coupling may further comprise at least one third retainer for cooperating with a fourth retainer associated with 5 said trunking members.

Using retainers, for example bolts or studs and nuts, on each internal surface of the coupling and each part of the coupling will ensure a secure and robust connection of the two adjacent trunking section. Furthermore, even if one nut is not correctly tightened on its respective bolt the security and strength of the junction of the trunking portions is not altered.

In a preferred embodiment at least one of said first and third retainers comprises a second aperture for receiving said second or fourth retainers in the form of a threaded member 15 extending therethrough.

In another preferred embodiment at least one of said first and second body portions comprises a seal engaging portion and a pair of flanges extending from said seal engaging portion and having said first or third retaining portions located therein.

By using the flange and in particular having holes extending through the flange, the advantage is provided that the flange can be screwed down onto the trunking section thereby pressing the seal into close engagement with the trunking section and improving the seal.

In a further preferred embodiment the first aperture extends through said body portion.

According to another aspect of the present invention there is provided a trunking section for joining further trunking sections together at angles not parallel to each other, the 30 trunking section comprising:-at least one substantially planar first wall; at least one second wall extending substantially perpendicular to a said first wall with a combination of three walls of said first and second walls defining an opening with a plurality of said openings being nonparallel to each other; and at least one insert for attachment to a said wall adjacent said pair of nonparallel openings, said insert including a fixing portion for fixing said insert to a said first or second wall not perpendicular to said opening and also including at least one extension portion extending from said fixing portion so as to create at least one surface perpendicular to a said opening adjacent said extension portion.

The insert defined above allows the simple construction of trunking section, that is used as a corner, T-or cross junction, to work with the coupling defined above or with other linear couplings, which are of simpler construction than those of the prior art. Furthermore, the insert allows internally fixed stud to be used on these junctions. In the prior art it is necessary to use bolt fixing which extend through the trunking from the outside because the internal geometry of the trunking sections when joined, specifically that they were not linear, prevents a linear coupling being used and this lack of linearity in the coupling makes it impossible to use stud fixings to secure the coupling to the trunking sections.

In a preferred embodiment the fixing portion comprises a 25 substantially planar surface for fixed connection to said wall.

In another preferred embodiment the fixed connection comprises welding.

In a further preferred embodiment the extension portion comprises a substantially V shaped cross-section with one 30 surface of said V-shape creating said surface perpendicular to said opening. -8 -

The above described shape is easily formed and easily fixed to the inside of the trunking section connector with a spot weld. This has all the advantages of a more complex connector without the difficulties associated with machine finishing the multiple welded edges resultant from the more complex shape.

According to a further aspect of the present invention there is provided a trunking system comprising:-a plurality of trunking sections; and at least one coupling device set out above.

In a preferred embodiment at least one said trunking section comprises a trunking section set out above.

Preferred embodiments of the present invention will now be described, by way of example only, and not and in any limitative sense with reference to the accompanying drawings in which:-Figures 1 and 2 are perspective views of trunking coupling devices of the prior art; Figure 3 is a perspective view of a trunking section of the prior art for connecting further trunking sections together; Figure 4 is a perspective view of a trunking coupling device of 20 the present invention; Figures 5 and 5A are a perspective view and an underneath view respectively of the coupling device of figure 4 in use with trunking sections; Figure 6 and 6A are a perspective view and an underneath view 25 respectively of a trunking section of the present invention for connecting further trunking sections together; Figure 7 is a perspective view of another trunking section of the present invention for connecting further trunking sections together; -9 -Figure 8 is a perspective view of a further trunking section of the present invention for connecting further trunking sections together; and Figure 9 is a perspective view of a further trunking section of 5 the present invention for connecting further trunking sections together.

Referring to figures 4, 5 and 5A, a coupling device 50 for use in connecting trunking sections 52 and 54 is provided as a plurality of separable components. One of these components is a first coupling member 56 which seals a junction 60 between a first wall 62 of trunking section 52 and a second wall 64 of trunking section 54 which are positioned adjacent or even in engagement with each other when the trunking sections are in use.

The first coupling member 56 has a pair of apertures or recesses 66 and 68 formed therein. These recesses 66 and 68 are located adjacent opposing ends of the first coupling member 56. The first coupling member 56 is formed from two components which are a sealing portion 70 and a body portion 72. The sealing portion 70 is formed from a rubberised material such as neoprene and is sufficiently deformable to substantially form a seal of the junction 60 between the adjacent first and second walls 62 and 64. The body portion 72 is formed from a material having a greater rigidity than the sealing portion and this is typically a sheet metal material such as stainless steel. The sealing portion 70 and body portion 72 are preferably fixed together and Lhis is mosL easily achieved using an adhesive. The sealing portion 70 has a length that is slightly greater than that of the body portion 72 so that the sealing portion extends beyond 30 the ends of the body portion 72.

The recesses 66 and 68 are formed as apertures extending through the body portion 72. The cross-section of the body -10 -portion 72 is substantially uniform and the body portion consists of a U-shaped main part 74, which extends around three sides of the sealing portion 70, and a pair of flanges 76 and 78. When the first coupling member 56 is not in use the sealing portion 70 extends slightly below the flange 76 and 78. These flanges have first retainers, in the form of apertures 80 and 82, which extend through the flanges and engage with second retainers associated with the first and second trunking sections 52 and 54. These second retainers are typically bolts which extend through apertures 84 and 86 formed in the trunking sections 52 and 54. As an alternative, these apertures 84 and 86 can be replaced with threaded studs welded to the inside surfaces of the trunking sections 52 and 54. The bolts or threaded studs extend through the apertures 80 and 82 on the 15 first coupling member 56 and are fixed thereto by cooperating nuts.

Also forming part of the coupling 50 are a pair of second coupling members 88 and 90 for sealing further junctions 92 and 94 between further walls 96, 98, 100 and 102 of the trunking sections which are adjacent the first and second walls 62 and 64. The construction of the second coupling members 88 and 90 is similar to that of the first coupling member 56 in that the second coupling members have sealing portions 104 and 106 and body portions 108 and 110. Similarly each body portion has a main part 112 and 114 and flanges 116, 118, 120 and 122 with first retainers, in the form of apertures 124, formed into the flanges. These apertures cooperate with bolts extending through further apertures 125 formed adjacent the ends of the trunking sections 52 and 54. As with the apertures 64 and 68 the apertures 125 can be replaced with threaded studs welded to the inner surfaces of the trunking sections.

The main structural difference between the first and second coupling members is that the second coupling members do not have the recesses 66 and 68 but instead have projections 126 and 128 which extend from the main parts 112 and 114 of the body portions 108 and 110. In use, the projections 126 and 128 extend into the recesses 66 and 68 to create some rigidity within the 5 formation of the coupling 50. In particular, the engagement of the projections 126 and 128 into the recesses 66 and 68 prevents the first coupling member 56 from sliding axially along the trunking sections 52 and 54. It is therefore possible to fix the coupling 50 without using the apertures 80 and 82 in the 10 first coupling member 56.

In the embodiments described above the coupling 50 has been used to connect and substantially seal linear sections of trunking and it is particularly effective where abutting surfaces of the adjacent trunking sections are coplanar. 15 Although it is commonplace to form corner trunkirg sections (that is trunking sections that are used to turn a corner) with surfaces that will be coplanar with the adjacent surfaces of an adjoining section of the linear trunking, it is preferable to create trunking sections with a simpler construction such as 20 that shown in figure 6. In this example the trunking section 130 is used to turn a 90° corner and is formed from a single sheet of stainless steel. The trunking section 130 is cut from the sheet material including a first wall 132. A series of three second walls 134, 136 and 138 are created by bending the sheet material to form corner edges 140, 142 and 144 respectively. The walls 134 and 136 are joined at edge 146 by welding and further bends create the retaining lips 148, 150 and 152 extending from walls 134, 136 and 138 respectively. Since this corner trunking section 130 can be formed from a single sheet material with a single welded corner 146 this simple construction makes this manner of producing such trunking corner sections particularly desirable.

-12 -However, on its own such a trunking corner section would not be able to operate with the coupling 50 because the second wall 138 is not coplanar with the wall 102 of the linear trunking section 54. As a result, an insert 154 is provided and this 5 forms a coplanar surface 156 with the internal surface of wall 102 of linear trunking section 54. The insert 154 is attached to the wall 138 which extends between a pair of nonparallel openings 158 (formed by the edges of walls 132, 136 and 138) and 160 (formed by the edges of walls 132, 134 and 138). The insert 10 154 has an attachment or central portion 162 which is fixed, typically by spot welding, to the internal surface of wall 138, this being a wall which is not perpendicular to either of the openings 158 and 160. The insert 154 has at least one, and in this example a pair of, extension portions 164 and 166.

The insert 154 has a substantially uniform cross-section and is formed from a sheet of metal material which is bent to form the central portion 162 and the extension portions 164 and 166. These extension portions are V-shaped in cross-section (see the plan view in figure 6A) and an outermost surface of one of the extension portions forms the surface 156 which is coplanar in use with the surface of wall 102 of trunking section 54. A similar surface, indicated at 168, at the other end of the insert 154 in use forms a coplanar surface with a wall of a trunking section (not shown). Because trunking section 130 is used to form a 90° bend the surfaces 156 and 168 are perpendicular to each other and it is these surfaces which the coupling 50 (not shown in figures 6 and 6A) is attached to when it is used to join a trunking section 130 to a linear trunking section 54. It is also worth noting that part of the purpose which this insert achieves is to provide a surface which is parallel to the surface of the opposing wall of the trunking section. In this example the surface 156 is parallel to the inside surface of wall 136 and the surface 168 is parallel to the internal surface of wall 134. The extension portions 164 and 166 are provided with -13 -threaded studs 170, 172, 174 and 176 and these extend through the apertures 124 in the second coupling member 88. The wall 136 is provided with apertures 178 and 180 through which threaded bolts (not shown) can be placed to fix, using retaining nuts, the other second coupling member 90 via the apertures 124.

This same insert can be used in other nonlinear trunking sections. In the example shown in figure 7, a T-junction trunking section 182 is shown. In this example, two inserts 154 have surfaces 156 and 168 which are coplanar with surfaces of the three linear trunking sections, all indicated as 54, which are connected to the T-junction trunking section 182. In this example the first and second walls of the T-junction trunking section 182 are similarly laid out to those in trunking corner section 130 with a first wall 184 having second walls 186, 188 and 190 extending perpendicular therefrom and formed by simply bending the second walls out of the plane of the first walls.

A further example of a trunking corner section junction using the insert 154 is shown in figure 8. This example is known as an outside bend and is used where the trunking turns from running horizontally to extending vertically downwards. This outside bend junction has a pair of openings 194 and 196 which are perpendicular to each other and is formed from a series of walls 198, 200, 202 and 204. It will be apparent to person skilled in the art that this trunking section junction can be formed from a single sheet of stainless steel which is bent to form the separate walls and is joined by a single weld which either fixes wall 200 to 202 or 200 to 204. For the purposes of this description, and for clear understanding of the claims, the first wall could be regarded as wall 198 with the second walls being regarded as the remaining walls 200, 202 and 204 or alternatively the first wall could be regarded as wall 200 with the second walls being regarded as the remaining walls 198, 202 and 204. A further similar example of a trunking section -14 -junction is shown in figure 9 which is a T-juncticn with the perpendicular part of the junction extending downwards. The insert 154 can be used in any junction of this type where the edges of the walls at the opening are nonparallel including the perpendicular bends and T-junctions described above, as well as non-perpendicular bends and T-junctions and cross junctions.

Operation of the apparatus of the present invention will now be described with particular reference to Figure 4, 5 and 5A. The first and second trunking sections 52 and 54 are brought into abutment with each other so that the ends of the walls 62, 64, 96, 98, 100 and 102 form the junctions 60, 90 and 92. The first coupling member 56 is positioned to cover the junctions 60 and bolts are positioned to extend through the apertures 84 and 80 and through the apertures 86 and 82. Cooperating nuts are located on the bolts and secured to hand-tight. This acts to hold the two trunking sections 52 and 54 together whilst the remainder of the coupling 50 is installed. The second coupling members 88 and 90 are positioned so that the projections 126 and 128 extend into the apertures 66 and 68 formed in the first coupling member 56. The sealing portions 104 and 106 are brought into engagement with the junctions 94 and 92 and bolts are positioned so as to extend through the apertures 125 and 124 before cooperating nuts are attached thereto and hand tightened. It will be appreciated that the process is made easier by replacing the apertures 84, 86 and each of the apertures 125 with threaded studs attached to the inner of the trunking sections 52 and 54 at the locations where these apertures are shown in the figures. The process for connecting the trunking sections shown in figures 6, 7 and 8 are substantially the same as that set out above.

It will be appreciated by persons skilled in the art that the above embodiments have been described by way of example only and not in any limitative sense, and that various alterations -15 -and modifications are possible without departure from the scope of the protection which is defined by the appended claims. For example, the first and second coupling members 56, 88 and 90 are described above is as being formed from separate sealing and body portions 70 and 72, 104 and 108, and 106 and 110. However, each coupling member can be formed as a single component from a single material if the properties of that material allow it to be both sufficiently pliable to form a seal but strong enough to hold the trunking sections together.

Furthermore, although the above description has suggested the use of three coupling members (one first coupling member and two second coupling members) the apparatus would also work by combining the first and one of the second coupling members together into a single L-shaped component. This L-shaped component would be angled into the trunking sections and locked into position by the remaining second coupling member. As previously mentioned, the apertures 80 and 82 in the flanges of the first coupling member could be eliminated. It is also possible that if these apertures are retained and studs fixed to the inside of the trunking members are used but the studs do not need to have the nuts fixed to them as the positioning of the second coupling members 88 and 90 would prevent the first coupling member from lifting over the studs.

Claims (20)

1. -16 -Claims 1. A coupling device for use in connecting trunking sections, the coupling device comprising:-a first coupling member for substantially sealing a junction between a first and a second wall on respective first and second trunking sections in use positioned adjacent each other, the first coupling member having a plurality of first apertures extending therein; and at least one second coupling members for substantially sealing further junctions between further walls of said first and second trunking sections adjacent said first and second walls and having respective projections for engaging said first apertures in said first coupling member and also having at least one first retainer for cooperating with a second retainer associated with said trunking members for retaining the second coupling member in engagement with said trunking sections.
2. 2. A device according to claim 1, wherein said first coupling member further comprising a first sealing portion and a first body portion formed from a material having a greater rigidity 20 than said first sealing portion.
3. 3. A device according to claim 2, wherein said first aperture is formed in said first body portion.
4. 4. A device according to claim 2 or 3, wherein said second coupling member further comprises a second sealing portion and 25 a second body portion formed from a material having a greater rigidity than said second sealing portions.
5. 5. A device according to any of claims 2 to 4, wherein said engaging member extends from said second body portion.
6. 6. A device according to any preceding claim, wherein said first coupling further comprises at least one third retainer for -17 -cooperating with a fourth retainer associated with said trunking members.
7. 7. A device according to claim 6, wherein at least one of said first and third retainers comprises a second aperture for 5 receiving said second or fourth retainers in the form of a threaded member extending therethrough.
8. 8. A device according to claim 6 or 7, wherein at least one of said first and second body portions comprises a seal engaging portion and a pair of flanges extending from said seal engaging portion and having said first or third retaining portions located therein.
9. 9. A device according to any of claim 2 to 8, wherein at least one of said first and second sealing portions comprise a rubberised material.
10. 10. A device according to any of claim 2 to 9, wherein at least one of said first and second body portions comprise a metallic material
11. 11. A device according to any of claim 2 to 10, wherein said first aperture extends through said body portion.
12. 12. A coupling device for use in connecting trunking sections substantially as hereinbefore described with reference to figures 4 and 5 of the accompanying drawings.
13. 13. A trunking section for joining further trunking sections together at angles not parallel to each other, the trunking 25 section comprising:-at least one substantially planar first wall; at least one second wall extending substantially perpendicular to a said first wall with a combination of three walls of said first and second walls defining an opening with a plurality of 30 said openings being nonparallel to each other; and -18 -at least one insert for attachment to a said wall adjacent said pair of nonparallel openings, said insert including a fixing portion for fixing said insert to a said first or second wall not perpendicular to said opening and also including at least one extension portion extending from said fixing portion so as to create at least one surface perpendicular to a said opening adjacent said extension portion.
14. 14. A trunking section according to claim 13, wherein said fixing portion comprises a substantially planar surface for 10 fixed connection to said wall.
15. 15. A trunking section according to claim 13, wherein said fixed connection comprises welding.
16. 16. A trunking section according to any of claims 13 to 15, wherein said extension portion comprises a substantially 15 V-shaped cross-section with one surface of said V-shape creating said surface perpendicular to said opening.
17. 17. A trunking section for connecting further trunking sections together at angles not parallel to each other substantially as hereinbefore described with reference to figures 6 to 9 of the 20 accompanying drawings.
18. 18. A trunking system comprising:-a plurality of trunking sections; and at least one coupling device according to any of claims 1 to 12.
19. 19. A trunking system according to claim 18, wherein at least 25 one said trunking section comprises a trunking section according to any of claims 13 to 17.
20. 20. A trunking system substantially as hereinbefore described with reference to figures 4 to 9 of the accompanying drawings.