GB2385898A

GB2385898A - Channel bolt

Info

Publication number: GB2385898A
Application number: GB0303905A
Authority: GB
Inventors: Christopher Richardson
Original assignee: Ultraframe UK Ltd
Current assignee: Ultraframe UK Ltd
Priority date: 2002-02-20
Filing date: 2003-02-20
Publication date: 2003-09-03
Also published as: GB0203932D0; GB0303905D0

Abstract

A channel bolt (18) has a head and a shank, there being engaging means (34) associated with the head, to inhibit sliding of the bolt (18) when in a channel. The engaging means (34) may be protrusions on a bearing surface (36) of the head, an adapted washer, a chock or displaced material of the channel.

Description

Title : Improvements in and relating to structural elements Description: The present invention relates to improvements in and relating to structural elements.

Building structures are often constructed from pre-fabricated building elements. Commonly, such building elements include extrusions that form struts or ties, which are cut to length and joined using fasteners or coupling elements to form the desired structure. As the technology relating to such building methods develops, it is common to have a selection of generic components that enable a variety of structures having a range of shapes, conformations and physical properties to be assembled. Examples of such generic components include support beams and braces that are joined by way of screws, bolts or adhesives or by joiners, comer pieces or flanges.

A need has arisen in recent years to assemble structures such as those outlined generally above, in an as aesthetically pleasing manner as possible. Means for achieving such an objective include decorative claddings to cover joins and fastening points, and fitting flashings that hide interfaces between adjoining structures. Accordingly, it is desirable to design building elements such that the fasteners and coupling elements

are hidden from view. To achieve this goal, generic building elements, as outlined above, commonly have formations such as captive bolt slots and countersunk recesses accessible from the one side of the component only. Furthermore, such structures may have a well-defined order of assembly so that as elements are added, they conceal the visible joins or fasteners associated with previously assembled elements.

Unfortunately however, in concealing fasteners and joins, the mechanical properties of the structure may sometimes be compromised.

For example, instead of drilling a hole through a pair of beams beam to allow for a bolted joint, one of the beams may incorporate a captivated bolt slot such that only one of the beams need be drilled. So long as the bolt is sufficiently tightened, the join will hold securely. However, should either the bolt or the beam yield with time or indeed during an overload or fatigue situation, the bolt head may subsequently slide within the captivated bolt slot when the load is removed.

A particular example of this problem may be in the joining of sloping conservatory roof glazing bars to an eaves or ridge beam. Owing to the load distribution of the structure, the weight of the roof or wind forces will tend to push the glazing bars either downwards and outwards, or upwards and inwards. Consequently, shear forces may be applied to the join between the glazing bars and the ridge or eaves beam. If the shear forces may be resolved in the general direction of the axis of a captivated bolt

slot, then the bolt head may be forced to slide, thereby either lowering or raising the ridge. Furthermore, should the glazing bars be unequally dislocated, unintended shear or torsional forces may be applied to other structural elements of the roof. Subsequently, either the safety of the structure may be compromised, or the appearance of the structure may be degraded.

It is therefore an object of the present invention to provide improved means for joining structural elements, wherein at least one of the elements incorporates a captivated bolt slot.

Accordingly, a first aspect of the present invention provides means for securing a first structural element having a channel therein to a second structural element having an aperture therein comprising a bolt having a head for location within the channel of the first structural element and a shank for protruding through the aperture of the second structural element and engaging means for inhibiting sliding of the bolt head within the channel.

Preferably, the channel is arranged to allow sliding of the bolt within the channel, but not twisting. The engaging means is preferably located between the bolt head and a channel surface of the first structural element. Preferably also, the engaging means comprises one or more protrusions integrally formed on the face of the bolt from which the shank extends whereby tightening a nut onto the shank of the bolt causes the

one or more protrusions dig into a channel surface of the first structural element.

The engaging means may comprise a plate adapted to locate between the bolt head and a channel surface of the first structural element, the plate having one or more protrusions integrally formed thereon whereby tightening a nut onto the shank of the bolt, causes the one or more protrusions of the plate dig into a channel surface of the first structural element. Additionally or alternatively, the plate is adapted to sit between the bolt head and a channel surface of the first structural element by the provision of an aperture in the plate.

Preferably the engaging means is manufactured of metal. The protrusions may be teeth, ridges or pins.

Additionally or alternatively, the engaging means is a chock. The chock may be adapted to allow it to be slidably inserted into the channel of the first structural element and wherein the chock is adapted to engage with one or more faces of the bolt. The chock may have selectively exposable self-adhesive means thereon to prevent it from sliding within the channel. Furthermore, the self-adhesive means may be selectively exposable by way of removing a peel-off element disposed between the self-adhesive means and one or more channel surfaces. The chock may be manufactured of a polymeric material. Alternatively, the chock may be fixed within the channel using mechanical fasteners.

Preferably, the bolt head is manufactured of a ductile material such that it deforms when a nut is tightened onto the shank. The deformation may be both radial and axial, whereby compression in the axial direction causes an expansion in the radial direction thereby engaging bolt head surfaces with channel surfaces of the first structural element.

Preferably also, the engaging means may be deformation of the channel proximate to the bolt head, which may involve crimping of the channel surfaces or displacement of material of a channel surface to form an abutment for the bolt head.

A second aspect of the present invention proposes that a captive bolt slot be deformed, so as to limit potential movement of a bolt head along the bolt slot.

According to a third aspect of the present invention there is provided a bolt intended for use in a captive bolt slot comprising: a bolt head and a shank wherein; the bolt head has protrusions on the face from which the shank extends whereby when a nut is tightened onto the shank of the bolt, the protrusions dig into a surface of the bolt slot thereby preventing the bolt from sliding in the bolt slot.

According to a fourth aspect of the present invention there is provided a method for preventing a bolt from sliding in a captive bolt slot comprising the steps of;

sliding the bolt to a desired position within the bolt slot, the bolt head having protrusions on the face from which the shank extends; and tightening a nut on the shank such that the protrusions on the bolt head dig into a surface of the bolt slot thereby preventing the bolt from sliding in the bolt slot.

According to a fifth aspect of the present invention there is provided an apparatus for securing two members being connected by a bolted joint comprising; a bolt ; a first member incorporating a captivated bolt slot for receiving the bolt head; a second member having an aperture for receiving the bolt shank; and a third member for obstructing or inhibiting the movement of the bolt head within the captivated bolt slot.

According to a sixth aspect of the present invention there is provided a method for securing two members being connected by a bolted joint comprising the steps of; inserting a bolt into a captivated bolt slot and; inserting a member into the captivated bolt slot for selectively obstructing or inhibiting the movement of the bolt within the slot.

According to a seventh aspect of the present invention there is provided a tool for peening the flanges of a captive bolt slot whilst the bolt is in-situ, comprising a body having; an aperture for locating around the bolt to align the body of the tool relative to the bolt and flanges ; and formations on the surface of the body that is intended to face the flanges such that; when the tool is struck in a direction generally towards the flanges, the formations on the tool impart a force on the flanges causing the flanges to deform, thereby preventing the bolt from sliding in the captive bolt slot.

A preferred embodiment of a second aspect of the present invention involves deformation of the bolt slot local to the bolt by any suitable means. Preferred deformations include crimping of the sides of the bolt slot local to the bolt head or by displacement of material of a side of the bolt slot to form an abutment for the bolt head.

A bolt proposed by the third and fourth aspects of the invention is preferably manufactured of a metal such as steel. The head of the bolt is of a size that can be accommodated in the bolt slot and may be generally round, square, hexagonal or any other convenient shape. The bolt has protrusions on the face from which the shank extends, however protrusions may also be provided on other faces so as to engage internally

with the side walls of the bolt slot. The protrusions are preferably sharp and may take the form of teeth, ridges or pins. Additionally or alternatively, the bolt head may be designed such that its diameter increases when a nut is tightened on the shank thereby further gripping the side walls of the bolt slot.

A preferred third member according to the fifth and sixth aspects of the present invention is a chock or washer.

Where the third member is a chock, it is preferably of a size that allows it to be slidably inserted into the bolt slot of the first member. The chock is preferably shaped to engage with the bolt and has formations thereon for making intimate contact with the bolt. The chock may be manufactured of a plastics material.

In use, a chock will preferably be inserted in the bolt slot, along with the bolt. The chock and bolt may then be located at a desired position before the chock is fixed in place. A chock may be used to prevent movement of the bolt within the bolt slot in a single direction. However, more than one chock may be used, on either side of the bolt, to prevent it from moving in either direction.

Additionally or alternatively, a single chock may be used that prevents movement of the bolt in both directions by having formations that engage with more than one face of the bolt. Preferably, the chock will

have formations that engage with opposite faces of the bolt that lie in the axis of the bolt slot.

The chock may be fixed in the bolt slot using mechanical fasteners such as screws or pins, or it may be fixed in place using an adhesive or self-adhesive strip.

Where however, the third member is a washer, it will preferably be manufactured of a material that is harder than the material from which the bolt slot is manufactured.

A preferred washer according to the fifth aspect of the present invention will be substantially flat and may be elongate to increase its surface area. The washer may have a have an aperture through which the shank, but not the head of the bolt may pass.

One face of the washer may have protrusions that dig into a surface of the bolt slot when a nut is tightened onto the bolt, thereby preventing the bolt from sliding within its slot. In use, the shank of the bolt will be passed through the aperture of the washer before the bolt is slid into the bolt slot. The protrusions of the washer will preferably face a surface of the interior of the bolt slot.

The protrusions are preferably sharp and may take the form of teeth, ridges or pins. Preferably also, there are protrusions on both sides of the washer so that the bolt and the bolt slot are gripped by the

protrusions and so that the orientation of the washer relative to the bolt slot is rendered less important.

The peening tool according to the seventh aspect of the present invention is preferably manufactured of a material that is substantially harder that the material of the bolt slot. In a preferred embodiment the tool is manufactured of a metal, such as steel.

The tool may have an aperture or be shaped in such a way that it is locatable on or about the shank of the bolt when the bolt head is located within the bolt slot at a desired position.

Preferably, the tool is either formed, or has formations on at least one surface such that when the tool is stuck, the formations cause the walls of the bolt slot to become indented or deformed thereby preventing the bolt from sliding in the bolt slot.

Embodiments of the present invention shall now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 shows an application for the present invention in connecting prior art roof beams to upright supports.

Figure 2 shows a section of Figure 1 on X-X.

Figure 3 shows a peened bolt slot in perspective.

Figure 4 shows a bolt in perspective with protrusions on a face of the bolt head

Figures 5 to 7 show exploded views of chocks in perspective for preventing sliding of a bolt in a bolt slot Figure 8 shows a bolt and a washer in perspective having protrusions intended to engage with at least one internal wall of a bolt slot and Figure 9 shows a perspective view of a tool for peening the flanges of a bolt slot.

Turning now to Figure 1 of the accompanying drawings, a schematic prior art pitched roof connected to a support structure 10 is shown. An upright support beam 12, having an eaves beam 14 connected thereto, is depicted. Normally, there are a plurality of spaced-apart upright beams 12 supporting a single eaves beam 14. Also shown is a roof beam 16 atop the eaves beam 14 being connected thereto be a bolt 18 and nut 20 arrangement. There are usually present, a plurality of spaced-apart roof beams 16, coincident with the spaced-apart upright beams 12.

Figure 2 is a section of Figure 1 on X-X showing the profile of a prior art roof beam incorporating a captive bolt slot 22. The bolt slot 22 comprises a channel 24 having an elongate aperture 26 running along its length. The width of the aperture 26 allows the shank 28 of a bolt 18 to pass through it. The channel 24 has dimensions that allow the bolt head 30 to slide along the channel 24, but not to rotate about the axis of the shank 28. By this arrangement, bolts 18 may be slidably located at

positions along the beam 16 but may be prevented from rotating. This arrangement negates the need for a spanner to be located on the bolt head 30 whilst tightening a nut 20 onto the shank 28.

Figure 3 shows an embodiment the invention whereby a bolt 18 is located in a bolt slot 22 of a beam 16. The flanges 30 of the bolt slot have been deformed 32 to prevent the bolt from sliding in the slot in the direction indicated by the arrow A.

Figure 4 of the accompanying drawings shows a bolt 18 according to the invention. The bolt 18 has formations 34 on the lower face 36 of the bolt head. The formations 34 of the bolt head dig into the walls of the channel 24 formed by the bolt slot 22, when a nut (not shown) is tightened onto the shank of the bolt 18.

Figure 5 shows another embodiment of the invention, in which there is depicted, a chock generally referred to as 40 having a body 42 and also having an aperture 44 and formations 46 that engage with the head of a bolt 18. The aperture 44 is of sufficient diameter to allow the shank of the bolt 18 to pass there through and the formations 46 engage with the bolt head to prevent it from rotating about the axis, generally referred to as B.

Additionally provided in the body 42 of the chock are apertures 48.

In use, the bolt 18 is slidably located in the body of the chock whereupon the chock 40 and bolt 18 are then slidably located in the bolt slot 22 at a

desired position. Screws 50 are then used to secure the chock to the flanges 30 of the bolt slot or to the beam 16.

Figure 6 shows an embodiment of the invention wherein the chock 40 is in a two-part form.

Figure 7 shows an alternative embodiment of the invention whereby the apertures 48 and screws 50, are replaced by a self-adhesive strip 52.

In use, the bolt 18 is positioned in the chock 40 and is slid into the bolt slot.

The self-adhesive strip 52 has a peel-away cover 54, which is removed in the general direction of the arrow labelled C through the slot 26.

Turning now to Figure 8, wherein a washer 52 having formations 54 on its flat faces and an aperture 56 for slidably accepting the shank of the bolt 18. The shank of the bolt 18 is passed through the aperture 58 and is slidably located in the bolt slot 22 of the beam 16. When a nut (not show) is tightened onto the shank of the bolt 18, the formations 54 of the washer 52 dig into the walls of the channel 24 formed by the bolt slot 22, thereby preventing the bolt 18 from sliding in the bolt slot 22.

Lastly, Figure 9 of the accompanying drawings shows a peening tool 60 according to the seventh aspect of the invention. The channel walls 30 of the bolt slot 22 are peened using the tool 60 to prevent the bolt 18 from sliding in the bolt slot 22 as indicated by the arrow A. The tool generally referred to as 60 has a body 62 and a face 64 having an aperture 66 and formations 68 thereon. The bolt 18 is located in the bolt

channel 24 at a desired position and the aperture 66 of the tool 60 is offered up to the shank of the bolt 18. The shank is then slidably located in the aperture 66 until the formations 68 of the upper surface 64 of the tool 60 make contact with the walls 30 of bolt slot 22. The tool 60 is then struck in a direction generally denoted by the arrow D, whereupon the formations of the tool 68 deform the walls 30 of the bolt channel 24 forming indentations 32 in the walls 66 of the channel 24 thereby preventing the bolt 18 from sliding in the channel 24 in the direction indicated by the arrow A.

Claims

Claims :

1. Means for securing a first structural element having a channel therein to a second structural element having an aperture therein comprising a bolt having a head for location within the channel of the first structural element and a shank for protruding through the aperture of the second structural element and engaging means for inhibiting sliding of the bolt head within the channel.

2. Means for securing as claimed in claim 1, wherein the channel is arranged to allow sliding of the bolt within the channel, but not twisting.

3. Means for securing as claimed in claim 1 or 2, wherein the engaging means is located between the bolt head and a channel surface of the first structural element.

4. Means for securing as claimed in claim any one of claims 1,2 or 3, wherein the engaging means comprises one or more protrusions integrally formed on the face of the bolt from which the shank extends whereby tightening a nut onto the shank of the bolt, causes the one or more protrusions dig into a channel surface of the first structural element.

5. Means for securing as claimed in any one of claims 1,2 or 3, wherein the engaging means comprises a plate adapted to locate between the bolt head and a channel surface of the first structural element, the plate

having one or more protrusions integrally formed thereon whereby tightening a nut onto the shank of the bolt, causes the one or more protrusions of the plate dig into a channel surface of the first structural element.

6. Means for securing as claimed in claim 5, wherein the plate is adapted to sit between the bolt head and a channel surface of the first structural element by the provision of an aperture in the plate.

7. Means for securing as claimed in any one of claims 1 to 6, wherein the engaging means is manufactured of metal.

8. Means for securing as claimed in any of claims 4 to 7, wherein the protrusions are teeth.

9. Means for securing as claimed in any of claims 4 to 7, wherein the protrusions are ridges.

10. Means for securing as claimed in claims 1 or 3, wherein the engaging means is a chock.

11. Means for securing as claimed in claim 10, wherein the chock is adapted to allow it to be slidably inserted into the channel of the first structural element and wherein the chock is adapted to engage with one or more faces of the bolt.

12. Means for securing as claimed in claim 10 or 11, wherein the chock has selectively exposable self-adhesive means thereon to prevent it from sliding within the channel.

13. Means for securing as claimed in claim 12, wherein the self-adhesive means is selectively exposable by way of removing a peel-off element disposed between the self-adhesive means and one or more channel surfaces.

14. Means for securing as claimed in any of claims10 to 13, wherein the chock is manufactured of a polymeric material.

15. Means for securing as claimed in claim 10 or 11, wherein the chock is fixed within the channel using mechanical fasteners.

16. Means for securing as claimed in any of claims 1 to 15, wherein the bolt head is manufactured of a deformable material such that it deforms when a nut is tightened onto the shank, the deformation being both radial and axial, whereby compression in the axial direction causes an expansion in the radial direction thereby engaging bolt head surfaces with channel surfaces of the first structural element.

17. Means for securing as claimed in claim 1 or 2, wherein the engaging means is a deformation of the channel proximate to the bolt head.

18. Means for securing as claimed in claim 17, wherein the deformation involves crimping of the channel surfaces.

19. Means for securing as claimed in claim 17, wherein the deformation involves displacement of material of a channel surface to form an abutment for the bolt head.

20. Means for securing substantially as hereinbefore described with reference to and as illustrated in Figures 3 to 9 of the accompanying drawings.