GB2218145A

GB2218145A - Turnbuckle

Info

Publication number: GB2218145A
Application number: GB8810465A
Authority: GB
Inventors: John Ewans
Original assignee: Thorsman and Co AB
Current assignee: Thorsman and Co AB
Priority date: 1988-05-04
Filing date: 1988-05-04
Publication date: 1989-11-08
Also published as: GB8810465D0

Abstract

The present invention provides a one-piece turnbuckle for fastening a first sheet member (14) to an edge of a second sheet member (19) (fig. 2), comprising a substantially cylindrical body portion (1), a head portion (2) at one end of the body portion, and an arm (5) projecting transversely at the opposing end of the body portion. The head portion is insertable through a hole (15) in the first sheet member, at least part (4) of the head portion being thereafter outwardly deformable to prevent withdrawal through said hole. The invention also provides a method of installing a one-piece turnbuckle as defined above in a sheet member using the deforming die 17. <IMAGE>

Description

TURNBUCKLE This invention relates to a turnbuckle, in particular a one-piece turnbuckle for fastening a first sheet member to an edge of a second sheet member. The turnbuckle is particularly, but not exclusively, useful for fastening a cover to a trough member for cable trunking.

In a conventional form of cable trunking, cables are accommodated in a trough member and a cover is fastened over the open side of the trough member. This fastening can be effected by screws and nuts, but then unfastening of the cover to gain access to the cables can be troublesome.

Quick-release turnbuckles can therefore be used for the fastening, and enable the cover to be removed with a simple quarter turn of the turnbuckles.

Conventional turnbuckles are made of at least two parts. A head portion is integral with a body portion the latter being placed through a suitable hole in the cover. A transversely projecting arm portion is then fixed to the end of the body portion projecting from the other side of the cover. This fixing may be effected by a suitable screw or the like. This method of installing the turnbuckle in the cover is cumbersome and does not lend itself readily to automation. Cable trunking covers provided with such turnbuckles have accordingly been relatively expensive.

An object of the present invention is to provide a one-piece turnbuckle and a readily automated method of installing it in a sheet member, such as a cable trunking cover.

The present invention thus provides a one-piece turnbuckle for fastening a first sheet member to an edge of a second sheet member, comprising a substantially cylindrical body portion, a head portion at one end of the body portion, and an arm projecting transversely at the opposing end of the body portion, said head portion being insertable through a hole in the first sheet member, at least part of the head portion being thereafter outwardly deformable to prevent withdrawal through said hole.

The invention also provides a method of installing a one-piece turnbuckle as defined above in a sheet member, which comprises inserting the head portion through a hole in the sheet member such that the head portion projects from the hole on the opposite side of the sheet member to the arm, and thereafter outwardly deforming at least part of the head portion such that it cannot be subsequently withdrawn through said hole.

Reference is now made to the accompanying drawings, in which: Figure 1 is a perspective view of a one-piece turnbuckle according to a referred embodiment of the present invention; Figure 2 is a diagrammatic side view showing how the turnbuckle fastens a cover to the body of a cable trunking member; Figure 3 is a diagrammatic, part sectional view showing installation of the turnbuckle before deformation of the head portion; and Figure 4 is a view corresponding to Figure 3 after deformation of the head portion.

The turnbuckle has a hollow, substantially cylindrical body portion 1 which is open along diametrically opposed sides. An enlarged circular head portion 2 covers one end of the body portion. The head portion is provided with an underhanging, peripheral lip 3 which is interrupted at four points to define two diametrically opposed securing tags 4 in register with the gaps in the cylindrical body 1.

Initially, these securing tags 4 are in line with the outer periphery of the head portion 2, as shown in Figures 1 and 3.

A double arm arrangement 5 is integral with the end of the body portion opposite the head portion. This comprises two diametrically opposed arms, having twin limbs 6, 7 and 8, 9, respectively. These arms extend on either side of the gap in the cylindrical body portion 1. The ends of the arms remote from the body are joined by integral cross members 10 and 11, respectively, and the cross members have upper ridge-shaped surfaces 12 and 13, respectively.

The turnbuckle is installed in a sheet member, such as a cable trunking cover, as shown in Figures 3 and 4. The sheet member 14 is provided with a circular hole 15 corresponding to the initial diameter of the head portion 2.

The head portion is inserted through this hole until it projects from the other side (Figure 3), further movement being prevented by an interrupted peripheral shoulder 16 on the upper surface of the arm assembly 5. The dimensions are such that the turnbuckle can freely rotate in the hole 15 and the upper ridge surfaces 12 and 13 are spaced from the underside of the sheet member 14. A punch 17 tappered at its end (known as a "drift") is pressed up the inside of the turnbuckle towards the head portion, as shown by the arrow in Figure 3. The tappered head of the drift 17 is dimensioned such that it will cause the securing tags 4 to be deformed outwardly as shown in Figure 4. When the drift has reached the limit of its travel towards the head portion, it is then retracted as shown-by the arrow in Figure 4.Now that the securing tags have been deformed outwardly, subsequent withdrawal of the head portion through the hole 15 is prevented. The turnbuckle is thus permanently in place in the sheet member. It will be readily appreciated that the method described with reference to Figures 3 and 4 can be automated.

Figure 2 shows how such a turnbuckle installed in the cover of a cable trunking assembly is used. The cover 18 corresponds to the sheet member 14 shown in Figures 3 and 4.

The body 19 of the cable trunking has a horizontal inner flange at its open edge. In the position shown in Figure 2, an upper ridge surface (12 or 13) of the turnbuckle fastens a first sheet member (the cover 18) to an edge of a second sheet member (the horizontal flange of the body 19). The top surface of the head of the turnbuckle is provided with a slot 20 for a screwdriver. Rotation of the turnbuckle through a quarter turn will release the cover from the trunking body.

Claims

CLAIMS:

1. A one-piece turnbuckle for fastening a first sheet member to an edge of a second sheet member, comprising a substantially cylindrical body portion, a head portion at one end of the body portion, and an arm projecting transversely at the opposing end of the body portion, said head portion being insertable through a hole in the first sheet member, at least part of the head portion being thereafter outwardly deformable to prevent withdrawal through said hole.

2. A turnbuckle according to claim 1, in which the head portion includes underhanging tags which are outwardly deformable by insertion of a deforming tool through the body portion towards the head portion.

3. A turnbuckle substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

4. A method of installing a one-piece turnbuckle according to any of claims 1 to 3 in a sheet member, which comprises inserting the head portion through a hole in the sheet member such that the head portion projects from the hole on the opposite side of the sheet member to the arm, and thereafter outwardly deforming at least part of the head portion such that it cannot be subsequently withdrawn through said hole.

5. A method according to claim 4, in which the deforming is carried out by inserting a deforming tool through the body portion towards the head portion, thereby outwardly deforming underhanging tags on the head portion.

6. A method of installing a one-piece turnbuckle substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

7. An assembly comprising a sheet member and a turnbuckle according to any of claims 1 to 3 or installed by a method according to any of claims 4 to 6.