GB2592127A - A turnbuckle for fixing a lid to one or more sections of trunking - Google Patents

Abstract

A device for fixing a lid 12 to one or more sections of trunking14 includes a bolt 16 with a shank having a non-circular portion and a threaded portion and a nut 28 for connection with the threaded portion. There is a tongue 34 having an aperture for location on the shank, that aperture corresponding with the shape of the non-circular portion thereby preventing rotation of the tongue 34 relative to the bolt 16. A washer 36 is located between the nut 28 and the tongue 34 and has a section of elastomer secured to a face of the washer 36 next to the tongue 34.

Description

Intellectual Property Office Application No G1321016902 RTM Date:21 May 2021 The following terms are registered trade marks and should be read as such wherever they occur in this document: Allen -Page 4 Intellectual Property Office is an operating name of the Patent Office www.gov.uk/ipo -1 -A Turnbuckle for Fixing a Lid to one or more Sections of Trunking The present invention relates to a turnbuckle and relates 5 particularly, but not exclusively, to a turnbuckle for securing a lid to one or more sections of trunking for cable containment.

The use of turnbuckles for securing components, such as trunking and a lid together via tension is commonplace. Such turnbuckles provide an advantage over other securing methods by allowing for adjustments in tension to be tuned easily. However, with the application of a force to provide such tension, it is not uncommon to apply an inaccurate amount of force to the nut, thereby producing an over tensioned or under tensioned turnbuckle. In such an example where the turnbuckle is over tensed manual rotation of the turnbuckle could become difficult due to the tongue surface catching against the extended flanges of the trunking. In a more severe case the tension could be such that the turnbuckle does not attach the lid to the section of trunking. This could produce fractures or faults in the turnbuckle or result in the lid being displaced and damaged. If the turnbuckle is under tensioned a disproportionate gap between the tongue and the extended flanges would result. This can result in the lids not being properly fixed to the trunking.

This in turn can result in a loose fitting between the lid and the trunking body wherein a good electrical earth continuity could not be achieved, any gaps between said fittings could additionally allow solid bodies to enter. Secondly this could lead to an audible noise if the trunking is installed in an environment where physical vibrations occur due to the tongue and said flanges knocking against each other. Furthermore, it could cause the turnbuckle to further loosen allowing for detachment of the lid from the trunking. This risks a lid falling from the item it is attached to and causing serious -2 -injury or damage to people or objects located below. Loose lids also risk not meeting the requirements of 1P4X which must provide protection against solid bodies greater than lmm in diameter.

Preferred embodiments of the present invention seek to 5 overcome or alleviate the above described disadvantages of the prior art.

According to an aspect of the present invention there is provided a turnbuckle for fixing a lid to one or more sections of 10 trunking, the turnbuckle comprising: a metal bolt having a shank with a non-circular portion and a threaded portion; at least one metal nut for connection with said threaded portion; at least one metal tongue having an aperture for location on 15 said shank, said aperture corresponding with the shape of said non-circular portion thereby preventing rotation of the tongue relative to the bolt; and at least one metal washer for location between said nut and said tongue, said washer having at least one section of elastomer 20 secured to a face thereof adjacent of said tongue.

By providing a washer with at least one section of elastomer attached to said washer face adjacent to said tongue provides a cushioned support point between the washer face surface and the tongue face surface. This support distributes the tension applied when securing the lid to the trunking. This in turn allows for the precise amount of force needed to securely rotate the tongue into the correct position without producing an over or under tensioned turnbuckle. With the turnbuckle securely in place and the correct tension applied any undesirable rattling noises or concerns of a loosening connection between trunking and lid are avoided. Furthermore, misalignment when locking the tongue in place under the flanges will be prevented. -3 -

In a preferred embodiment, the nut used to securely attach all the individual components of the turnbuckle to the threaded section of the bolt will be a self-securing nut with a material insert.

In another preferred embodiment, the external diameter of the elastomer section will be smaller than the external diameter of the washer.

According to another aspect of the present invention there is an enclosed system comprising of: a trunking component having a base and upright sides with inwardly-directed flanges between at least two open ends defined on three sides thereof by said base and upright sides and an open top; a lid adapted to close said open top and having at least one 15 aperture formed therein; and at least one turnbuckle according to any of the preceding claims, wherein said bolt extends through at least one said aperture and said tongue engages said flange to fix said lid to said trunking component.

Preferred embodiments of the present invention will now be described, by way of example only, and not in any limitative sense with reference to the accompanying drawings in which:-Figure 1 is an isometric view of a washer with a section of elastomer secured to the top face therein; Figure 2 is an isometric view of a deconstructed turnbuckle showing the correct positioning of the washer in figure 1 between the tongue and the nut; and Figure 3 is an isometric view of the trunking system with the present invention engaging with the lid.

Referring to the figures, a turnbuckle 10 is provided for fixing a lid 12 to one or more sections 14 of trunking which is -4 -used for carrying and protecting electrical cables (not shown) and the like. The turnbuckle 10 includes a bolt 16 which is formed from a metal material such as stainless steel and has a head 18 and a shank 20. The head 18 has a driver receiving portion in the form of a slot 22. Although this could alternatively be any suitable means for applying a rotational force to the bolt 16, including, but not limited to, recesses for receiving other shapes of screwdriver such as a crosshead driver, Phillips driver or Allen key and could be an alternative shape of head such as a hexagonal head.

The shank 20 is divided into a threaded portion 24 and a noncircular portion 26. The threaded portion 24 has an external helical threat and is distal of the head 18. The noncircular portion 22 has a square cross-section and is located between the threaded portion 24 and the head 18. Although a square cross-section has been used in the embodiment shown in the figures, non-circular cross-sectional shapes can be used including, but not limited to, other polygons and shapes having finite rotational symmetry, such as an ellipse.

A nut 28 also forms part of the turnbuckle 10 and has an internal thread 30 which corresponds with the external thread of threaded portion 24 of bolt 16. The nut 28 is a locking nut and has a material insert, in the form of a plastic ring which is formed adjacent one end of the thread 30. The plastic insert 32 grips the external thread 24 requiring a predetermined torque to be applied to the nut 28 to allow rotation of the nut on the external thread of the bolt.

The other components of the turnbuckle 10 are a tongue 34 and a washer 36. Looking first at the turnbuckle 34, this component has a central portion 38 and a pair of ends 40. An aperture 42 is provided in the central portion 38 and this is shaped to correspond with the noncircular portion 26 of the shank 20 of bolt 16. In other words, the shape of the aperture 42 is substantially the same as the cross-section of the noncircular portion 26, although very slightly larger in its dimensions so as to allow the noncircular portion 26 to enter the aperture 42. The ends 40 of turnbuckle 34 have deflector portions 44 which are the corners of the ends and have been slightly bent out of the plane of the metal from which the tongue 34 is formed by bending along the dotted lines indicated at 46.

Turning finally to the washer 36, as shown in detail in figure 1, this component is formed in two parts, these being a metal base 48 which, like a standard washer, is annular with a circular aperture 50 and, although formed from a planar sheet of stainless steel is formed with a concave and convex face. Attached to, and preferably strongly adhered to, the base 48 is a section of an elastomeric material, such as rubber and is adhered to the concave face of the base 48. The elastomer is also annular and has an aperture 54. Although the apertures 50 and 54 have approximately the same diameter the external diameters of the elastomer 52 and base 48 (D1 and D2, respectively, on figure 1) are not the same. D1 is slightly smaller than D2 to accommodate the slight expansion of the elastomer under compression.

Operation of the turnbuckle 10 in conjunction with the lid 12 and trunking section 14 will now be described. The lid 12 has an aperture 60 for receiving the turnbuckle 10. The aperture 60 is sized so that the noncircular portion 26 of bolt 16 can extend therethrough and the bolt can freely rotate within the aperture. The assembly of the turnbuckle 10 on lid 12 is such that the shank 20 of the bolt 16 extends through the aperture 60 with the head 18 of the bolt located on the outer surface 62 of the lid 12. With the shank 20 extending through the aperture 60 the tongue 34 is then located onto the shank so that the square aperture 42 is aligned with the square cross-section portion 26 of the bolt 16. More specifically, the alignment is -6 -such that the slot 22 runs parallel to the length of the tongue 34. This allows easy identification of the correct alignment of the tongue 34 when in use on the underside, and therefore invisible to an operator, of the lid 12. The tongue 34 is secured onto the shank 20 of the bolt 16 using the nut 26 with the washer 36 located between the nut and the tongue. Specifically, the washer is aligned so that the section of elastomer 52 engages the tongue 34 and the base 46 engages the nut 28. However, this arrangement can in principle be reversed. 10 In assembling the turnbuckle 10 on the lid 12, it is preferable that the nut is secured to a predetermined torque using a torque limiting wrench.

When the lid 12 and turnbuckle 10 have been assembled, as described above, the lid 12 can be secured to the section of trunking 14. This trunking component has a base 64 and upright sides 66 and 68, from which extends generally inwards a pair of flanges 70 and 72. In order to attach the lid to the section of trunking 14, the turnbuckle is rotated so that the slot 22 and the tongue 34 are aligned with the length of the lid 12.

The lid is then placed onto the trunking section 14 and the tongue 34 sits between the flanges 70 and 72. Rotation of the head 18 of the bolt 16, by engagement of a screwdriver into slot 22, causes rotation of the tongue 34, due to the correspondence between the noncircular portion 26 of the shank 20 and the aperture 42 in the tongue. The ends 40 of the tongue 34 are able to engage the flanges 70 and 72, sliding under these flanges by virtue of the deflected portions 44. When the slot 22 and tongue 34 are aligned perpendicular to the length of the lid 12, the ends 40 of the tongue engage the flanges 70 and 72, thereby retaining the lid 12 on the trunking section 14. The lid can be released by rotation of the head 18 so as to align the slot 22 with the length of the lid 12.

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 imitative sense, and that various alterations and modifications are possible without departure from the scope 5 of the protection which is defined by the appended claims. For example, although the washer 36 and apertures 50 and 54 formed therein are described as circular other shapes of washer and apertures would also work. With the exception of the elastomeric section 52, all of the components described above are preferably 10 made from stainless steel. However, they can be formed from other metallic materials. The washer 36 is preferably formed with concave and convex surfaces. However, a planar base 48 to the washer is also acceptable. Furthermore, although the section of elastomeric material 52 has been described as being a rubber material, any suitable elastomeric material including, but not limited to, other rubber materials, vulcanised rubbers and thermoplastic materials may be used. The tongue described above has two ends 40 which engage the flanges 70 and 72. However, under some circumstances only a single end is required as the turnbuckle is engaging a single flange. Although the above embodiment was described using a standard locking nut with a plastic insert, other methods of locking the nut 28 onto the bolt 16 can be used including, but not limited to, the addition of a second nut or the use of adhesive to fix, at least temporarily, to the bolt.

Claims (4)

1. Claims 1. A turnbuckle for fixing a lid to one or more sections of trunking, the turnbuckle comprising: a metal bolt having a shank with a non-circular portion and a 5 threaded portion; at least one metal nut for connection with said threaded portion; at least one metal tongue having an aperture for location on said shank, said aperture corresponding with the shape of said non-circular portion thereby preventing rotation of the tongue 10 relative to the bolt; and at least one metal washer for location between said nut and said tongue, said washer having at least one section of elastomer secured to a face thereof adjacent said tongue.
2. 2. A turnbuckle according to claim 1, wherein said nut is self-locking.
3. 3. A turnbuckle according to claim 2, wherein said self-locking nut has a material insert.
4. 4. A turnbuckle according to any of the preceding claims, wherein an external diameter of said elastomer secured to said 20 washer is less than an external diameter of said washer.S. An enclosed system comprising of: a trunking component having a base and upright sides with inwardly-directed flanges between at least two open ends defined on three sides thereof by said base and upright sides and an 25 open top; a lid adapted to close said open top and having at least one aperture formed therein; and at least one turnbuckle according to any of the preceding claims, wherein said bolt extends through at least one said aperture and 30 said tongue engages said flange to fix said lid to said trunking component.