GB2527600B

GB2527600B - Fastener

Info

Publication number: GB2527600B
Application number: GB1411497.9A
Authority: GB
Inventors: Stephen Atkinson David
Original assignee: Legrand Electric Ltd
Current assignee: Legrand Electric Ltd
Priority date: 2014-06-27
Filing date: 2014-06-27
Publication date: 2019-10-30
Anticipated expiration: 2034-06-27
Also published as: GB201411497D0; GB2527600A

Description

FASTENER

FIELD

There is provided a fastener, an assembly comprising the fastener and a method for using the fastener.

BACKGROUND

Cable tray assemblies are used for routing cabling and comprise a number of components including, at least, cable tray sections. The cable tray sections may be of standardised configurations, such as straight sections and corner sections.

Fasteners (also referred to herein as fastening means) are used to fasten cable tray sections together to form a cable tray assembly using a bracket. A known fastener is described in International patent application number WO 92/04755 A1. The fastener in this document is described as comprising a spring clip made from spring steel rod. It is shaped in V-configuration and has a right angled step at the apex of the V to define a portion which can be passed through a first pair of aligned apertures in overlapped components of a cable tray assembly (such as a bracket/coupler and a cable tray). The extremities of the rod have steps which can, after stressing the clip to narrow the V-configuration, be passed together through another aperture of a second pair of aligned apertures in component of the cable tray assembly.

The inventor(s) for the present invention have identified the challenge of further facilitating the assembly of cable tray sections. In particular, to improve the coupling provided by the fastener described in WO 92/04755 A1.

SUMMARY

The present invention is defined by the appended independent claims. Certain more specific embodiments are defined by the dependent claims.

Such fasteners represent an improvement over the fastener described in WO 92/04755 A1. In particular, the feature of the fastener being configured such that, when fastening together overlapping, substantially parallel sheet sections of cable tray components, the fastener presses said sheet sections together using at least the first end section and the intermediate section by acting to return to a relaxed state in which the relative orientation of the first end section and the intermediate section has a greater angular difference than when the fastener is being used to fasten said sheet sections together, and or the feature of intermediate section being bent such that when the fastener is fastening cable tray components together, the greatest force exerted by the intermediate section on the sheet sections is located in the region of said bend, improves the fit between the connector and the components in the cable tray assembly, reducing rattle and sliding motion between the components. Reducing rattle and sliding motion leads to an improved joint strength and electrical continuity between components.

One of the cable tray components may be a first cable tray section and the other cable tray component may be a bracket.

This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Nor is the claimed subject matter limited to implementations that solve any or all of the disadvantages noted in the Background section.

FIGURES

An embodiment of the present invention is described below, by way of example only, with reference to the accompanying drawings, in which:

Figures 1A and 1B illustrate an example fastener; and

Figures 2A, 2B and 2C illustrate an assembly of cable tray components fastened using the fastener of Figures 1A and 1B.

DETAILED DESCRIPTION A cable tray component is a component used for forming a cable tray assembly. A cable tray component may be any of a bracket, a coupler and a cable tray section for carrying cables. These are given as example cable tray components only and are not limiting. A cable tray component comprises at least one aperture, through which at least one of the ends of the fastener is configured to pass in order to contact a surface on the other side of the cable tray component. The contact is a pressing force.

The fastener may be suitable for fastening other components together, depending on the relative dimensions of the connection points of those components and on the dimensions of the intermediate section. In general, the first and second end sections of the fastener are configured to be inserted through aligned apertures of components being connected. In this context, the term “aligned apertures” covers those cases where there is only a partial alignment between apertures on two separate components to be fastened. The apertures should overlap to the extent that the first and/or second end section (whichever is configured to pass through those aligned apertures) may pass through them. The length of the intermediate section determines the length of the spacing between the aligned apertures through which the first and second end sections are respectively configured to pass.

In the above, it is mentioned that the first and second end sections are displaced from the intermediate section in a same direction via respective steps. In particular, the same direction is perpendicular to the intermediate section, although it is understood that the step(s) may have components in directions that are parallel to the intermediate section. The parallel components of the steps do not have to be the same as each other, and may even be in opposing directions. This can be visualised by assuming that the intermediate section is the topmost section and the first and second end sections lie below it (or alternatively that the intermediate section is the bottommost section and the first and second end sections lie above it). The displacement is such that, when fastening sheet sections of cable tray component, the first and second end sections are configured to press together sheet sections from an opposite side to the side pressed by the intermediate section. In the following, the steps connecting the first and second end sections to the intermediate sections are S-shaped (orZ-shaped) bends in the fastener. The steps are preferably approximately equal in length.

In further embodiments, the intermediate section is bent such that when the fastener is fastening cable tray components together, the greatest force exerted by the intermediate section on the sheet sections is located in the region of said bend. Preferably, the end of the intermediate section that is closest to the second end section extends away from a cable tray component being pressed by the intermediate section. Thus the greatest force exerted by the intermediate section on any of the cable tray components rests in the region of the bend in the intermediate section.

The angular difference described above may be predominantly a result of the relaxed state angle of the first end section. By this, it is meant that the first end section is configured to rotate about the step connecting the first end section to the intermediate section during fastening so as to decrease the angular difference therebetween.

The angle of the first end section, the intermediate section and the step(s) connecting them are configured such that only part of the first end section is configured to contact one of said sheet sections. This leads to the greatest pressure being exerted by the first end section on a cable tray component in the region where the first end section contacts the cable tray component. This is in the region of the first end section that is furthest from the intermediate section. When the fastener is not fastening sheet sections of components together (and/or is free of deforming forces), it is known as being in the relaxed state. In the relaxed state, at least one of the end portions and the intermediate portion of the fastener have parts thereof that are separated from each other in a direction perpendicular to the direction in which sheet sections are configured to lie in the fastener by a distance smaller than the combined thickness of the sheet sections.

The fastener may be formed from a suitable material, such as a steel spring rod. For a particular structure of fastener, the material is selected to provide an elastic modulus E such that the fastener seeks to return to that structure if the fastener is removed from a cable tray assembly. In other words, the fastener is elastic (also known as flexible) with respect to the forces applied in fastening overlapping (co-planar), sheet sections of cable tray sections together.

When the fastener is formed from a spring rod, the first end section may form a hoop and the second end section may comprise two free extremities. The hoop may be substantially C-shaped. The intermediate section would then comprise two arms, each leading from a respective free extremity in the second end section to a respective end of the hoop in the first end section. In other words, both ends of the spring rod reside in the second end section whilst a central portion of the spring rod resides in the first end section of the fastener.

The two free extremities of the second end section are preferably configured to be sprung into an aperture in at least one cable tray component. The two free extremities may be brought together, for example, by the application of an external force on opposing sides of the second end section or of the intermediate section. Once brought together, they may be passed through aligned apertures of two components to be fastened together before being released. As, as mentioned above, the elasticity of the fastener material is such that, after being deformed by use in a cable tray assembly, the fastener returns to its original shape, the free extremities move apart again in the absence of an application of an external force. This leads to the steps connecting the free extremities to the intermediate section “hooking” onto or into opposing sides of the aperture through which they extend.

Preferably, each of the free extremities face in opposite directions to each other. This means that, when the steps connecting the free extremities to the intermediate section “hook” onto the aperture, the free extremities point in opposite directions away from the centre of the aperture. If the “hooking” of the steps is said to provide a horizontal retaining force to prevent movement in a horizontal direction, the free extremities can be said to provide a vertical retaining force to help prevent movement vertically. In other words, the steps between the intermediate section and the second end section are configured to prevent lateral movement between the cable tray components whereas the forces exerted by the first and second end components and the intermediate components are configured to prevent the separation of the cable tray components.

In an embodiment, the cable tray components to be fastened together are two cable tray sections and a bracket. The bracket is used to provide a supportive connection between the two cable tray sections and is fastened to each of the cable tray sections. A single fastener may be configured to fasten the components together. For example, the first end section may be configured to pass through aligned apertures of the bracket and one of the cable tray sections whilst the second end section is configured to pass through aligned apertures of the bracket and the other cable tray section.

In an embodiment, the cable tray components to be fastened together are two cable tray components, one of which being at least partly nestled within the other cable tray component. In this case, the first end section is configured to pass through aligned apertures of the two cable tray components and the second end section is configured to pass through other aligned apertures of the cable tray components. Thus each of the cable tray components in this case has at least two apertures that are configured to at least partially align with respective apertures on the cable tray component to which it is to be fastened.

One of the cable tray components may be a first cable tray section and the other cable tray component may be a bracket. The assembly may further comprise a second cable tray section having a sheet section coplanar with the sheet section of the first cable tray section. In this case, the sheet section of the bracket comprises a second aperture configured to align with an aperture in the sheet section of the second cable tray such that the other end section of the fastener may pass through. Thus the intermediate section of the fastener extends across the join (and/or gap) between the coplanar sheet sections of the cable tray sections and the end sections are directly above or below respective cable tray sections.

As in the case described above, the force may be a squeezing force that is applied to the fastener in the intermediate section. It is understood that other types/locations of externally applied forces may achieve the effect of bringing the free extremities closer together, such as a squeezing force applied to the free extremities themselves. However, as the first and second end sections are configured for insertion through respective aligned apertures in the cable tray components, it is advantageous to apply the force to the intermediate section, which is not configured to pass through aligned apertures in the cable tray components.

Hereinafter there is described a particular embodiment of a fastener (and an assembly comprising the fastener) with reference to figures 1A to 2C. Features in the different Figures that are labelled with the same reference numeral are equivalent to each other.

Figure 1A is an isometric view of the fastener. The fastener is formed of a single piece of spring rod material. Two ends of the spring rod are each comprised within the second end section 104, which comprises free extremities 104a and 104b corresponding to respective ends of the spring rod. The free extremities 104a and 104b are connected to respective arms 102a and 102b in the intermediate section 102 via respective steps 103a and 103b. The arms 102a and 102b of the intermediate section extend in a direction that is perpendicular to the steps 103a and 103b and that is perpendicular to the free extremities 104a and 104b.

The arms 102a and 102b of the intermediate section 102 are connected to the first end section 100 via respective steps 101a and 101b. The first end section 100 is configured so that the spring rod forms a C-shape. Each free end of the C-shape is connected to a respective step 101a and 101b for connection to the arms 102a and 102b of the intermediate section 102. In profile, the first end section is angled relative to the intermediate section so that they are not co-planar. Both the first and second ends 100, 104 are displaced from the intermediate section 102 in a same direction. A view along A-A’ in Figure 1A is depicted in Figure 1B. In this view, free extremity 104a is shown coming out of the page. Step 103a connecting free extremity 104a to arm 102a is perpendicular to free extremity 104a and appears to extend upwards before bending to connect with arm 102a in the intermediate section 102. Arm 102a is shown as comprising a slight bend, or kink, 105. Bend 105 is such that the central portion of the arm 102a is vertically closer to the free extremity 104a than the part of the arm 102a closest to the free extremity. At the opposite end of the arm 102a to the step 103a, there is another step 101 a, which connects arm 102a to the first end section 100. The step 101a is not parallel with the step 103a. Instead, the step 101a is angled away from the arm 102a as the step 101 a nears the first end section 100. The first end section 100 is also angled, although it is perpendicular to the step 101a. The first end section 100 is angled so that at locations furthest from the intermediate section 102, the first end section is vertically closer to the intermediate section 102 than it is at locations closest to the intermediate section.

The use of such a fastener as described in relation to Figures 1A and 1B when forming a cable tray assembly is depicted in Figures 2A to 2C.

Figure 2A shows the fastener 201 of Figures 1A and 1B fastening together a bracket 202 with a first cable tray 203 and a second cable tray 204. The combined bracket-fastener feature therefore connects the first and second cable trays 203, 204. The first cable tray 203 and the second cable tray 204 are adjacent to each other. Both of the first and second cable trays are nestled within bracket 202 such that any gap or join between them is covered on at least one face by the bracket 202. The bracket 202 and first and second cable trays 203, 204 comprise apertures 205 (depicted in Figure 2B).

As shown in Figure 2A, the first end section 100 of the fastener 201 is configured to contact a face of the bracket 202. As the first end section 100 is angled, only part of the first end section 100 directly contacts the bracket 202. In particular, the part of the first end section 100 furthest from the intermediate section 102 is the only part of the first end section 100 configured to contact the bracket 202. This means that a force is directly exerted on the bracket by the first end section 100 only through part of the first end section 100 (i.e. the contacting part of the first end section 100).

The intermediate section is configured to contact at least one (and preferably both) of the cable trays 203, 204. As the intermediate section 102 comprises a slight bend, only part of the intermediate section 102 directly contacts the cable tray(s) 203, 204. This means that a force is directly exerted on the cable tray(s) 203, 204 by the intermediate section 102 only through part of the intermediate section 102 (i.e. the contacting part of the intermediate section 102).

The second end section 104 is configured to contact the same face of the bracket 202 as the first end section 100. The first and second end sections 100, 104 of the fastener 201 are configured to exert a force on the bracket 202 that is opposite in direction to the force exerted by the intermediate section 102 on the cable trays 203, 204.

Figure 2B depicts a top-view of the assembly of Figure 2A. In the Figure, items that are disposed on the underside of the cable trays (such as part of the bracket 202 and the first and second end sections 100, 104) are indicated by dashed lines.

Figure 2B shows that the bottommost surface of the cable trays 203, 204 comprises a plurality of apertures, at least one of which on each cable tray is at least partially aligned with a respective corresponding aperture 205, 206 on the bracket 202. It is also noted in Figure 2B that there is a small gap separating cable tray sections 203, 204 in the direction along which the intermediate section 102 extends. The size of this gap is determined by the alignment of the bracket apertures 205, 206 with the cable tray apertures. To reduce sliding between cable tray components 201,202, 203, 204, and to reduce rattling, the tolerance of the components is preferably high.

Figure 2C is a view along the cross-section of Figure 2B indicated by the line B-B’. Figure 2C illustrates the cable tray 203 (having substantially an L-shape) nestled at least partly within bracket 202. Bracket 202 contacts the cable tray 204 on both outer-faces of the L-shaped cable tray 203. Fastener 201 is shown as having first and second end sections 100,104 that contact the bracket 202 and an intermediate section 102 that contacts the cable tray section 203.

In the above described example of Figures 2A to 2C, the cable assembly components 201,202, 203, 204 are all made of steel.

In view of the foregoing description it will be evident to a person skilled in the art that various modifications may be made to the above-described embodiments within the scope of the invention.

Claims

1. A fastener for fastening together overlapping, substantially parallel sheet sections of cable tray components to form a cable tray assembly, wherein the fastener comprises: a first end section configured for passing through at least one first aperture of the cable tray components to a location adjacent to the at least one first aperture; an intermediate section; and a second end section configured for springing into at least one second aligned aperture of the cable tray components, wherein said second end section is connected to the first end section via the intermediate section, wherein the first and second end sections are displaced from the intermediate section in a same direction via respective steps; wherein the fastener is configured such that the fastener presses said sheet sections of the cable tray components together using at least the first end section and the intermediate section by acting to return to a relaxed state in which the first end section and the intermediate section are oriented at a greater angle relative to each other than when the fastener is being used to fasten said sheet sections together; wherein the angle of the first end section, the intermediate section and the step therebetween are configured such that only part of the first end section is configured to contact one of said sheet sections; and wherein the intermediate section is configured to extend parallel to the sheet sections in a region adjacent to the at least one first aperture, with said first end section passed through the at least one first aligned aperture and said second end section sprung into the at least one second aligned aperture.

2. A fastener as claimed in claim 1, wherein the intermediate section is bent such that when the fastener is fastening cable tray components together, the greatest force exerted by the intermediate section on the sheet sections is located in the region of said bend.

3. A fastener as claimed in claim 1 or claim 2, wherein the angle of orientation between the first end section and the intermediate section is predominantly a result of the relaxed state angle of the first end section.

4. A fastener as claimed in any preceding claim, wherein the fastener is formed from a spring rod, the first end section forming a hoop and the second end section comprising two free extremities.

5. A fastener as claimed in any preceding claim, wherein the second end section comprises two free extremities configured to be sprung into the at least one second aperture in at least one cable tray component.

6. A fastener as claimed in claim 5, wherein each of the free extremities face in opposite directions to each other.

7. A fastener as claimed in any preceding claim, wherein said fastener is configured to fasten a bracket to two adjacent cable tray sections, the first end section being configured to pass through aligned apertures of the bracket and one of the cable tray sections, and the second end section being configured to be sprung into aligned apertures of the bracket and the other cable tray section.

8. A fastener as claimed in any of claims 1 to 6, wherein said fastener is configured to fasten two cable tray components, the first end section being configured to pass through aligned apertures of the two cable tray components, and the second end section being configured to sprung into other aligned apertures of the cable tray components.

9. A method for fastening together overlapping, substantially parallel sheet sections of cable tray components to form a cable tray assembly, wherein the method comprises: passing a first end section of a fastener through at least one first aperture of the cable tray components to a location adjacent the at least one first aperture; springing a second end section of the fastener into at least one second apertures of the cable tray components, wherein said second end section is connected to the first end section via an intermediate section of the fastener, wherein the first and second end sections are displaced from the intermediate section in a same direction via respective steps; and wherein the fastener is configured such that the fastener presses said sheet sections of the cable tray components together using at least the first end section and the intermediate section by acting to return to a relaxed state in which the first end section and the intermediate section are oriented at a greater angle relative to each other than when the fastener is being used to fasten said sheet sections together; wherein the angle of the first end section, the intermediate section and the step therebetween are configured such that only part of the first end section is configured to contact one of said sheet sections; and wherein the intermediate section is configured to extend parallel to the sheet sections in a region adjacent to the at least one first aperture with said first end section passed through the at least one first aperture and the second end section sprung into the at least one second aperture.

10. A method according to claim 9, wherein the second end section comprises two free extremities, and the method further comprises: passing the first end section through the at least one first aperture of the cable tray components; applying a force to the fastener so as to bring the two free extremities closer together; passing the two free extremities through the least one second aperture of the cable tray components; and removing said force so that the free extremities move away from each other.

11. A method as claimed in claim 10, wherein the force is a squeezing force applied to the intermediate section.