GB2344119A

GB2344119A - Hangers for dovetailed metal decking sections and method of installation

Info

Publication number: GB2344119A
Application number: GB9926694A
Authority: GB
Inventors: Julian Mark Dison; John Michael Dison
Original assignee: H Gordon and Co Ltd
Current assignee: H Gordon and Co Ltd
Priority date: 1998-11-13
Filing date: 1999-11-12
Publication date: 2000-05-31
Anticipated expiration: 2019-11-12
Also published as: GB9824890D0; GB9926694D0; GB2344119B

Abstract

A hanger comprises a wire which is bent to form a retention portion (1) with a product receiving limb (3) extending from the retention portion. The retention portion has at least two abutments (15, 19) which, in the installed position (Figure 5) cooperate with opposite sides of the dovetail channel adjacent its base. The abutments are formed either by bends (13, 15, 19) which connect limbs (7, 9, 11) or by the limbs themselves. To install the hanger (Figures 2, 3 and 4) it is turned perpendicular to the plane of the decking to give an entry profile which is narrower than the mouth of the dovetail channel, the hanger is moved into the mouth until the retention portion is inside the channel until the first abutment means locates in one corner of the channel and the second abutment means locates in the other corner. In further embodiments the retention section is disclosed as having three and four abutments cooperating with the sides of the dovetail channel.

Description

DESCRIPTION Title: Hangers for dovetailed metal decking sections and the installation thereof.

The present invention relates to hangers for use with dovetailed metal decking sections and to a method of installing same.

Metal decking sections are in widespread use for forming composite floors for multiple story buildings, especially commercial and industrial buildings. A typical metal decking section is formed by rolling metal sheet and has a plurality of dovetail section channels disposed in side by side relation. In the installed position the dovetail channels present slots open to the underside of the decking section and hangers have been designed to be received in said slots for suspending various services therefrom e. g. cables, cable ducts, conduits etc. The channels of the most popular decking have incline sides which converge towards the open mouth thereof, hence the term dovetail decking. This term is used herein for any profiled decking which has channels which have narrow open mouths and especially those which have side walling which converges towards the open mouth, but without limitation to the latter.

The depth of the channel and the width of the open mouth may vary from one decking design to another. By way of example, decking designs with which we are particularly concerned will have mouth widths typically of the 40mm, but for any nominal width tolerance variations are quite wide and a variation of the order of + or-2mm is not uncommon. Larger profiles are also known with correspondingly wider mouths.

One design of clip for dovetail application is the wedge nut. The wedge nut comprises a body which has a width which is less than the width of the open mouth so that the nut can be introduced into the channel section but as viewed at 90 to its width it has a wedge shape which is generally complimentary to the shape of the dovetail of the decking section. Accordingly the wedge nut can be introduced into the channel by upward movement then in one orientation and when rotated through 90 in the plane of the decking section, the subsequent downward movement brings it into contact with the converging sides of the dovetail. The body has a threaded through hole to receive a complimentary stud which projects from the mouth and can have fixing brackets secured to it. To avoid unintentional rotation of the wedge nut after installation the threaded stud can be screwed up so that its upper end contacts the base of the channel thereby holding the wedge nut downwardly in contact with the sides of the channel.

It is the aim of the present invention to provide a fixing for use with such profiled metal decking which is economical to produce. It is another aim of the invention to provide a fixing for profiled metal decking which can be easily installed. It is another aim of the invention to provide a fixing for use with profiled metal decking which once installed provides a secure fixing which can be used for a wide range of loads.

Accordingly, a first aspect of the invention provides a hanger for use with profiled metal decking having one or more dovetail channels (as herein defined), the hanger comprising a wire which is bent to form a retention portion and a product receiving limb depending from the retaining portion, the retention portion being adapted to be received, in use, within a said dovetail channel and which in an installed position extends between and abuts the opposite sides of the dovetail and adjacent the base thereof, the retaining portion having at least two abutments which in use cooperate with one or the other sides of the dovetail channel to secure the hanger with respect thereto.

In one embodiment the retaining portion has at least three abutments and has an entry profile when tilted from its installed position which is narrower than the open mouth whereby said retaining portion can be introduced into the channel section.

As used herein a dovetail channel denotes a channel having an open mouth which is narrower than other parts of the channel. More specifically, each channel comprises a base and two sidewalls which converge towards an open mouth, but without limitation to same.

In contrast to the aforesaid wedge nut which is rotated about an axis extending perpendicular to the plane of the decking to permit entry into the channel section, the hanger according to one embodiment of the present invention is installed by movement in a plane which is disposed perpendicular to the plane of the decking section. The present invention advantageously provides a rapidly installed positive fixing.

Another aspect of the invention provides a method of installing a hanger into a dovetail channel (as herein defined) of a profiled metal decking section, in which method the hanger is turned in a plane perpendicular to the plane of the decking to present an entry profile which is narrower than the width of the open mouth of the dovetail, moved upwardly to enter the open mouth with or without further pivoting in said plane until a retention portion of the hanger is entrant into the channel, and thereafter moving said hanger in said plane towards its installed position to cause first abutment means of said retaining portion to locate in one corner region of the channel and thereafter urging further abutment means of said retaining portion to locate in the other comer of the channel accompanied by deformation of the retaining means then extending between said opposite sides of the channel.

To facilitate use as a fixing, it is preferred to have said product receiving limb project downwardly out of the open mouth. The form of the projecting part will to a large extent be determined by the nature of the service which is to be secured/suspended therefrom. It may be straight for application of insulation directly thereto, or for attachment of a further wire, for example, using a spring connecting clip. Alternatively the end may have a hook or loop to facilitate attaching a wire thereto for suspended ceiling applications.

One particular application of the hanger is for securing thermal insulation or in particular fire protecting material up to the metal decking, especially fire protecting material in the form of fibre board. For such an application the downwardly projecting part conveniently comprises a length of circular wire depending from the retention means -say of the order of 3-4mm diameter, and having a free end onto which the fibre board can be impaled in substantially the same manner as is used for securing such fire protection material to structural steel work. A dished retaining washer is pushed onto the end of the pin which projects through the fibre board to retain the fibre board in position.

For such an application substantial upward movement of the pin has to be resisted and accordingly the abutment of the retention portion with the base of the dovetail section provides the necessary resistance.

In one embodiment the wire of the retention portion comprises at least one limb having a dimension which is just greater than the width of the channel at the base.

More preferably, the retention portion has at least two limbs, and more preferably it has three limbs. Preferably the limbs define at least three abutments which in tum cooperate with sides of the dovetail channel. More preferably there are four abutments.

According to another aspect of the invention there is provided a method of installing a hanger into a dovetail channel (as hereindefined) of a profiled metal decking section, in which method a hanger made from wire and having a retention portion providing at least three abutments disposed at intervals along the wire and in a substantially common plane has rotation resisting abutment means engaged with one side of the dovetail channel and at least another abutment deflected in said plane to cause it to enter the dovetail channel and engage the other side of the channel.

The rotation resistant abutment means may comprise two point contact abutments or one linear abutment. The point contact abutments are formed by bends between limbs of the retention portion. The linear abutment is formed by a limb.

In one embodiment two abutments are engaged with one side of said dovetail and two abutments are deflected to permit them to be engaged with the other side.

The present invention will now be described by way of example only with reference to the accompanying drawings; in which: Figure 1 is a perspective view of as first embodiment of wire form hanger according to the invention, Figures 2 to 5 illustrate the steps for installing the hanger of figure 1 in a dovetail channel of a profiled metal decking section; Figure 6 is a perspective view of an other embodiment of profiled metal decking section incorporating a dovetail channel, and Figures 7,8 and 9 are perspective views of other embodiments of hangers according to the invention.

Referring firstly to figure 1, a hanger according to the invention comprises a length of wire which is bent to form a retaining portion 1 and a product receiving limb 3 depending from the retaining portion. In one embodiment the retaining portion is adapted to cooperate with opposite ends of the dovetail channel and has at least three abutments which in use cooperate with one or the other sides of the dovetail channel (adjacent its base) to secure the hanger with respect thereto.

The retaining portion comprises at least first 7 and second 9 limbs and at least the first limb is dimensioned to span across the dovetail channel and has bends 15,19 to its opposite ends which in one application serve as abutments which engage the opposite sides of the channel. More particularly the retaining portion has a third limb 11 which is connected by a bend 13 to the second limb 9. The second limb is connected to the first limb by bend 15. In one application bend 15 serves as a first abutment, bend 19 serves as a second abutment and where said third limb is provided its end 17 functions as an abutment (hereinafter referred to as the third abutment 17). In one application the third abutment 17 engages with the same side of the dovetail channel as said first abutment.

The bend 13 between the second limb and the third limb may function as a further abutment which is engageable with the same side of the channel as the second abutment.

The aforementioned first, second and third limbs are disposed in substantially the same plane. The bends are acute bends so as to return the wire compared with the direction of the preceding limb but by less than 180 . The product receiving limb 3 extends substantially perpendicular to said plane. It connects with said first limb by a bend 19 which curves in said plane to define said second abutment and then curves at 21 in a perpendicular plane so that the limb 3 depends at a position inset from the second abutment. The product receiving limb is substantially straight and has a free end in this example.

The vacinity of the bend 19 defining the second abutment also serves as a location point for a fixing tool used in one method of installation. In such a method the vacinity of the aforesaid further abutment 13 also serves as a location point for said fixing tool. The method of installation is described further hereinafter with reference to figures 2 to 5.

The drawings illustrate schematically one dovetail channel of profiled floor decking, typically rolled out of sheet steel. The dovetail has a base 25, opposite sides 27, 29 extending from the base and convergent to define an open mouth 31 to the channel which is narrower than the base. The profiled decking is installed with the open mouth opening downwardly as illustrated in figures 2 to 5. Flanges 33 extend laterally from the sides of the open mouth to the next adjacent dovetail channel (not illustrated).

It will be noted from figure 2 that the retaining portion of the hanger is introduced into the open mouth of the channel with the hanger pivoted in a clockwise direction (as viewed in figure 2) compared to its final installed position. This allows the end portions remote from the product receiving limb to be introduced into the channel whereupon the hanger is pivoted anticlockwise so that the abutrnents/bends 13,19 also enter the mouth and is then moved upwardly until it is in the position illustrated in figure 3. A position will be reached where the distance between a line passing through abutments 13,19 and a line passing through abutments 15,17 will be greater than the spacing between the sides of the channel if the limbs were not able to deflect to fit the available space. When this positions is reached, the hanger will be held by the resistance exerted by the spring wire from which it is formed. This position approximates to that shown in figure 3-but for ease of illustration the abutments are shown clear of the sides. This is also true for figure 4.

In order to secure the hanger more positively, a drift 37, comprising a piece of sheet metal of a width sufficient to span the bends of abutments 13,19, has one end engaged with said bends and force is applied to the other end, conveniently using a hammer 39 or the like, so that the retaining portion is urged fully into the channel and the abutments 13, 19 locate in one comer of the channel 41 and the abutments 15, 17 locate in the other comer 43 as seen most clearly on figure 4. Limb 7 is caused to bow. In this position the deformation of the limbs of the retaining portion serves to hold the hanger securely.

Figure 5 is a partially cutaway perspective view showing the hanger being urged into the fully installed position using drift 33.

Referring now to figure 6, here there is illustrated an alternative embodiment of profiled floor decking. It is shown upside down for ease of illustration and description. It has a plurality of generally trapezoidal ridges 51 and troughs 53 disposed in alternate side by side relation.

The troughs include in their roof portion 55 a dovetail channel 57. We use the term dovetail to denote a channel which has a mouth which is narrower than the opposite sides 59,61. In this embodiment the dovetail channel is relatively shallow and the aforedescribed method of installation is inappropriate.

An alternative installation technique is used and whilst a clip of the same design as that shown in figure 1 can be used it is preferable to modify the clip to suit the alternative installation technique. Three different embodiments are illustrated in figures 7,8 and 9. The embodiment of figure 7 most closely corresponds to that of figure 1. The main difference is in the lengthening of limbs 9 and 11 relative to the length of limb 7 for the reason which will be apparent from the description of the installation. There is a consequential increase in the angles of the bends 15, 13. The same reference numerals have been used to denote corresponding parts.

In the installed position of the hanger illustrated in figure 7 it adopts the configuration illustrated. Chain dotted lines represent the sides 59,61 of the dovetail channel 57. Thus abutments 13, 19 engage one side and abutments 15,17 the other side.

Installation is achieved by first engaging abutment 19 into the recess formed by the side 61 where it extends away from the open mouth to the base 57. Then the limb 11 is grasped and pivoted anticlockwise in the illustration towards the side 61. This brings the bend into contact with the side 59 and is further deflected against the resilience of the material until the end 17 can pass through the open mouth to engage in the dovetail. In the embodiment the limbs 9,11 are dimensioned to cause bend 13 to engages side 61 during the installation procedure. Limb 7 is caused to bow. The resistance of the spring retaining portion holds the hanger securely in position. The four abutments provide good stability.

Figure 8 shows an alternative embodiment which has been found to function equally well. By comparison with the embodiment of figure 7 limb 9 is shortened so that the bend 13'between it and the limb 11 does not act as an abutment. In addition limb 11 is extended to provide a leg 17'connected thereto by an obtuse bend. The leg 17'acts as the abutment and also by virtue of the increased length acts as a lever for aiding deflection of the limbs during installation. The dotted outline shows the position of the limbs prior to deflection to fit into the recess of side 59. The limbs are deflected in the plane that they occupy to facilitate insertion of the abutments 17'. It will be apparent that the installation procedure follows that for figure 7.

Finally figure 9 illustrates how a clip which is configured substantially like that of figure 1 can be inserted into the dovetail channel in an altemative orientation. Thus the limb 7 acts as an abutment which makes contact with and is received in the recess of side 61, whilst limb 11 acts as the abutment with the recess of side 59. The bends 15 and 13 flex to permit installation of the limb 11 after limb 7 has been engaged in its recess. The limb 11 may be extended to act as a lever.

Claims

CLAIMS 1. A hanger for use with profiled metal decking having one or more dovetail channels (as herein defined), the hanger comprising a wire which is bent to forrn a retention portion and a product receiving limb depending from the retaining portion, the retention portion being adapted to be received, in use, within a said dovetail channel and which in an installed position extends between and abuts the opposite sides of the dovetail and adjacent the base thereof, the retaining portion having at least two abutments which in use cooperate with one or the other sides of the dovetail channel to secure the hanger with respect thereto.
2. A hanger as claimed in claim 1 in which the retaining portion has at least three abutments and has an entry profile when tilted from its installed position which is narrower than the open mouth whereby said retaining portion can be introduced into the channel section.
3. A hanger as claimed in claim 1 or 2 in which the wire of the retention portion comprises at least one limb having a dimension which is just greater than the width of the channel at the base.
4. A hanger as claimed in claim 1 or 2 or 3 in which the retention portion has at least two limbs
5. A hanger as claimed in claim 1,2 or 3 or 4 in which the retention portion has three limbs.
6. A hanger as claimed in claim 5 in which there are four abutments.
7. A hanger as claimed in claim 1 in which the retaining portion comprises at least first and second limbs and at least the first limb is dimensioned to span across the dovetail channel and has bends to its opposite ends which in one application serve as abutments which engage the opposite sides of the channel, the bend between the first and second limbs constituting a first abutment, and the bend to the other end of the first limb being the second abutment.
8. A hanger as claimed in claim 7 and further comprising a third limb which is connected by a bend to the second limb.
9. A hanger as claimed in claim 8 in which a free end of the third limb functions as a third abutment.
10. A hanger as claimed in claim 9 in which the third abutment engages with the same side of the dovetail channel as the first abutment.
11. A hanger as claimed in claim 10 in which the bend between the second limb and the third limb functions as a further abutment which is engageable with the same side of the channel as the second abutment.
12. A hanger as claimed in claim 8 in which the first, second and third limbs are disposed in substantially the same plane
13. A hanger as claimed in any one of claims 7 to 12 in which the product receiving limb connects with the first limb by a compound bend which position same inset from the second abutment.
14. A hanger as claimed in claim 11 in which the first abutment and the further abutment serve as a location point for a fixing drift.
15. A hanger as claimed in claim 1 in which a first limb has bends to its opposite ends, one of which leads to the retention portion and the other leads to a second limb and wherein, in use, the first limb act as an abutment contacting one side of the dovetail channel, and the end of the second limb remote from the first limb or a third limb connected thereto by a bend contacts the other side of the dovetail channel.
16. A hanger as claimed in claim 1 in which a first limb is dimensioned to span across the dovetail channel section and has bends to its opposite ends which form first and second abutments which contact the opposite sides of the dovetail channel, a second limb connected to the first limb by a bend which forms said first abutment, and a third limb connected to the second limb by a bend, and wherein the third limb leads to an abutment which, in use, contacts the same side of the dovetail channel as the first abutment, said limbs being disposed in substantially the same plane.
17. A hanger as claimed in claim 16 in which the free end of the third limb provides the abutment.
18. A hanger as claimed in claim 16 in which the third limb has an obtuse bend which leads to a further limb which forms said abutment.
19. A hanger as claimed in claim 18 in which the second and third limbs are shorter than the first limb.
20. A method of installing a hanger into a dovetail channel (as herein defined) of a profiled metal decking section, in which method the hanger is turned in a plane perpendicular to the plane of the decking to present an entry profile which is narrower that the width of the open mouth of the dovetail, moved upwardly to enter the open mouth with or without further pivoting in said plane until a retention portion of the hanger is entrant into the channel, and thereafter moving said hanger in said plane towards its installed position to cause first abutment means of said retaining portion to locate in one comer region of the channel and thereafter urging further abutment means of said retaining portion to locate in the other comer of the channel accompanied by deformation of the retaining means then extending between said opposite sides of the channel.
21. A method of installing a hanger into a dovetail channel (as herein defined) of a profiled metal decking section, in which method a hanger made from wire and having a retention portion providing at least three abutments disposed at intervals along the wire and in a substantially common plane has rotation resisting abutment means engaged with one side of the dovetail channel and at least another abutment deflected in said plane to cause it to enter the dovetail channel and engage the other side of the channel.
22. A hanger constructed and arranged substantially as herein before described with reference to and as illustrated in any of Figures 1, 7,8 or 9.
23. A method of installing a hanger into a dovetail of a metal decking sections substantially as described with reference to Figures 2 to 6 or 9.