GB2393209A

GB2393209A - A hinged clamp with aperture for suspension element or fastener

Info

Publication number: GB2393209A
Application number: GB0318028A
Authority: GB
Inventors: Simon Klippel; Neil Frank Gill
Original assignee: Tyco European Metal Framing Ltd
Current assignee: Tyco European Metal Framing Ltd
Priority date: 2002-08-02
Filing date: 2003-08-01
Publication date: 2004-03-24
Also published as: GB0217988D0; GB0318028D0

Abstract

A hinged clamp 1 with two opposing jaws 2, 3 that contact the upper and lower surfaces of a structural element in use. One of the jaws 3 incorporates a first aperture 67b remote from its contact surface that is adapted to receive a suspension element or fastener 920. The other jaw 2 may incorporate a second aperture 67a that is also adapted to receive the suspension element. The jaws may each be joined to the connecting portion incorporating the hinge 15 via a secondary hinge 4a, 4b. The jaws 2, 3 of the clamp 1 maybe U-shaped. The clamp 1 may be used to support a grid on a beam. The hinge may be formed from a blank 61 that is also useful as a wall tie. Also disclosed are a method of suspending a utility component from a structural element and a process for manufacturing the clamp.

Description

-1- 2393209

Clamp The present invention relates to a clamp incorporating one or more hinges for suspending a utility component from a structural element (such as a beam) or for securing a structural element (such as a grating) to supporting metalwork, to its use in a method for suspending a utility component from a beam or in a method for securing a grating, to a process for its manufacture and to a blank from which it may be obtained by folding.

A conventional beam or flange clamp for suspending a utility component from a structural element such as a beam comprises a main body which is drilled or tapped at its rear portion in order to secure a drop rod outside and separate to the clamping region by means of rivets or bolts. the operation of this clamp is illustrated schematically in Figures la and lb. A beam (or flange thereof) 7 is inserted in jaws 1 and clamped directly by appropriate manipulation of cup point set screw 2 and locking nut 3. A rear portion of the main body 5 is provided with a tapped or clear hole 4 for securing a threaded or non-threaded drop rod respectively (not shown in Figure la). Figure lb illustrates the use of the clamp with a J bolt 6 passing through hole 5 for suspension of (for example) pipework.

The load bearing characteristics of the conventional clamp are largely unsatisfactory. For example, a utility component suspended from the drop rod exerts a significant disruptive moment about the separate clamping region. Moreover for use on tapered beams, it is imperative that the set screw bites into the tapered face of the flange (rather than the horizontal face) otherwise installation may fail.

-2- WO-A-00/52343 (Tyco European Metal Framing Limited) discloses a rigid clamp comprising two C-shaped plates whose respective ends are connected by a boss. Each boss defines a path for receiving a drop rod so that when the clamp is located on the beam, the drop rod is inserted into the lower boss and is secured to the underside of the beam. Thus the drop rod becomes a load bearing element acting directly at the clamping region. Although this improves the clamping performance of the clamp, the drop rod is incapable of vertical adjustment after installation and must be uninstalled and replaced should a height adjustment be required. Numerous clamps for securing a grating (such as a horizontal floor grating for a walk way) to supporting metalwork are known. Such gratings are commonly of a meshed structure constructed from flat bars connected in parallel by regularly spaced perpendicular spiral bars. Most of these clamps have a plurality of parts to grip the metalwork which are fastened by a threaded fastener. Their multiplicity of parts and less than straightforward assembly render them disadvantageous.

The present invention seeks to improve clamps by incorporating a hinge to serve as an effective mechanical reaction point countering the effects of compression as the jaws of the clamp are tightened. More particularly, the present invention relates to a clamp incorporating a hinge which exhibits improved load bearing capabilities whilst permitting the suspension element to be vertically adjustable.

Thus viewed from one aspect the present invention provides a clamp comprising: a first jaw and a second jaw connected rearwardly by a connecting portion incorporating a hinge, wherein the first

-3 jaw and second jaw have opposing contact surfaces which in use contact the lower surface and upper surface respectively of a structural element, wherein the first jaw incorporates a first aperture remote from the contact surface and adapted to receive a suspension element or fastener.

Such is the versatility of the clamp, it may be used in connection with structural elements having a range of shapes and sizes eg for securing the structural element or for suspending from the structural element a utility component.

Moreover the location of the first aperture is such that the suspension element is vertically adjustable which avoids any necessity for the clamp as a whole to be uninstalled should the need arise to adjust the height of the suspension element. The structural element is typically a beam (or a flange thereof) for which the clamp may be able to withstand a load of lOOOkg or a meshed structural element such as a grating (eg a floor grating of the type used in constructing a walkway). Typically the suspension element is a drop rod but numerous other suspension elements (such as J-bolts) may be used. From the suspension element may be suspended utility components such as fixing brackets, pipe supports, fire protection equipment, cable trays, cables, wires, electrical conduits, heating equipment, ventilating equipment or air conditioning equipment. Equally the clamp of the invention may be furnished with one or more piercings, apertures, slots and tabs either for suspending directly any of the previous utility components or for suspending indirectly from conventional means any of the above-mentioned utility components (but especially electrical cables, pipes and wires

-4 from cable/wire clamps, clips and ties or hoses from snapper hose clamps).

The first jaw may incorporate a first aperture rearwardly or forwardly of the contact surface. In a preferred embodiment, the second jaw incorporates a second aperture substantially collinear with the first aperture, wherein the first and second aperture are adapted to receive the suspension element or fastener.

In use, the clamp of the invention may be secured to the structural element by passing the suspension element or fastener through the first aperture (and optionally the second aperture). The first and second aperture may be tapped or non-tapped to receive a threaded or nonthreaded suspension element or fastener as desired.

The (or each) nut may be a standard hexagonal nut. The (or each) nut may be a pressed steel nut (eg in the form of a u-

shaped threaded clip which may be slid onto the base of the jaw over the aperture so as to position the thread either internally or externally). The (or each) nut may be a rivetted nut such as a RIVNUT_ (eg a nut with a short tubular collar which may be tightly crimped, deformed or rivetted to attach to the jaw to form a female thread or may be loosely crimped, deformed or rivetted to attach to the jaw but remain rotatable).

Where the aperture itself is threaded, the material at the aperture may be deformed or shaped (eg by punching) to form the threaded portion. However, the aperture may be Flow Drilled (ie drilled using a special drill bit which generates frictional heat sufficient to render plastic the steel around the aperture so that it flows and deforms into a thin tube which may be tapped to form the threaded portion).

-5 By way of example, the first aperture may be non-tapped and the suspension element or fastener may be fastened by a first hexagonal nut tightened against the exterior surface of the first jaw and (optionally) a second hexagonal nut tightened against the interior surface of the first jaw. Similarly, the second aperture may be non-tapped and the suspension element or fastener may be fastened by a first hexagonal nut tightened against the exterior surface of the second jaw and (optionally) a second hexagonal nut tightened against the interior surface of the second jaw.

By way of a preferred example, the first aperture may be non-

tapped and the second aperture may be punched or flow drilled to form the threaded portion or be provided with a nut (eg a pressed steel nut or rivetted nut). The fastener or suspension element passes through the first aperture and engages the second aperture so that subsequent rotation draws together the first and second jaws advantageously without the need for actuating tools such as spanners.

By way of a preferred example, the first aperture may be flow drilled to form the threaded portion or be provided with a tightly crimped rivetted nut and the second aperture may be provided with a loosely crimped, rotatable rivetted nut. The fastener or suspension element rotates through the first aperture and second aperture to the desired height from where the rotatable, rivetted nut may be rotated to draw together the first and second jaw.

The first and second jaw may have essentially the same or a different width. For use with a beam, the first and second jaw will have essentially the same width. For use with a grating, the second jaw will be wider than the separation of adjacent bars of the grating and the first and second jaw may have different widths.

-6- Preferably each of the first jaw and second jaw comprises a reentrant body extending rearwardly into the connecting portion incorporating the hinge. Particularly preferably each of the first jaw and second jaw comprises a substantially U-

shaped channel member, the floor of which extends rearwardly into the connecting portion incorporating the hinge. The leading end of the substantially U-shaped channel member is preferably open. The leading end of the substantially U-

shaped channel may have a cut-away portion or be turned inwardly. Preferably the junction of the first jaw and connecting portion incorporating the hinge constitutes a secondary hinge. Preferably the junction of the second jaw and connecting portion incorporating the hinge constitutes a secondary hinge. Particularly preferably the junction of the first jaw and connecting portion incorporating the hinge constitutes a first secondary hinge and the junction of the second jaw and connecting portion incorporating the hinge constitutes a second secondary hinge.

The (or each) secondary hinge permits the first and second jaw to securely contact a range of structural elements. For example, this embodiment may be advantageously used where the upper and lower surfaces of the structural element are substantially horizontal or where one or both of the upper and lower surface is tapered (outwardly or inwardly). The interaction of the hinge and secondary hinges may advantageously cause the first and second jaw to close in a substantially parallel manner. When the upper and lower surfaces of the structural element are horizontal, the parallel closing first and second jaw contact the lower and upper surface without adjustment. When the structural element is outwardly tapered on the upper surface (such as is the case with the flange of a channel, IPN, S beam or RSJ), the

-7- first and second jaw close until the leading edge of the second jaw contacts the upper surface whereupon it adjusts to contact the tapered upper surface (whilst the first jaw remains horizontal and in contact with the lower surface).

Preferably the opposing edges of the connecting portion incorporating the hinge taper outwardly from the hinge to the (or each) secondary hinge.

Preferably the connecting portion incorporating the hinge is convex. This has the advantage that (in use) a hollow exists between the trailing end of each of the first and second jaws and the hinge which may usefully be used for suspending pipes or electrical conduits and other such utility components. By way of example, the connecting portion incorporating the hinge may adopt a substantially arcuate shape (such as a U-

shape or C-shape) or an angled shape (such as a substantially V-shape). To make the hollow larger and therefore more usable, the trailing end of the first and/or second jaw are preferably inwardly tapered. The hollow may be strengthened with a conventional cable guide, sleeve or gland (eg a plastic cable guide, sleeve or gland) for feeding electrical conduits or pipes more securely and protecting them from abrasion on the suspension element or fastener. The plastic cable guide, sleeve or gland may be usefully colour coded (as is common in the electrical industry).

Preferably the connecting portion incorporates a weakened region which acts as the hinge. The weakened region may be an undercut. For example, the undercut may comprise substantially U-shaped cuts on opposing edges of the connecting portion. Preferably the undercut comprises substantially U-shaped cuts on opposing edges of the connecting portion, each tail end of which is chamfered.

-8 The weakened portion may be undercut to an extent sufficient to render the jaws manually manipulable. This permits the clamp (in use) to be located adjacent the leading edge of the structural element and applying firm pressure to bring the contact surfaces into contact with the upper and lower surface of the structural element. The resistance to bending of the material at the hinge is a function of its thickness and width which may be tailored accordingly.

In order for the reaction point to the fastening of the suspension element or fastener to coincide essentially with the hinge, the distance (lever arm) from the hinge to the suspension element or fastener and from the mid-point of the contact between the contact surfaces of the first and second jaw and the lower and upper surfaces of the structural element may be judiciously chosen.

The contact surface of the first and second jaw will depend on the utility of the clamp. The contact surface of the first jaw may be the surface of an edge ( en the "gum"). The contact surface of the first jaw may be the surface of its floor. The contact surface of the second jaw may be the surface of an edge ( eg the "gum"). The contact surface of the second jaw may be the surface of the roof thereof (the "palate"). Where the structural element is a beam, the contact surface of the first jaw and second jaw is generally the surface of its edges (the "gums"). Where the structural element is a grating, the contact surface of the first jaw is generally the surface of its edges (the "gums") and the contact surface of the second jaw is the surface of its roof.

The whole or a portion of the contact surface of the edge of either or both of the first and second jaw may be toothed.

For example, the whole or a portion of the contact surface of the edge of either or both of the first and second jaw may be

- 9 - provided with a plurality of teeth (eg optionally flattened, substantially V-shaped teeth or substantially e-shaped teeth). The contact surface of the edge of either or both of the first and second jaw is preferably provided at or near to its inner end with a step which in use abuts a surface (eg the leading edge) of the structural element. This advantageously assists installation of the clamp by permitting the installer to push the step against the leading edge of the structural element and steady the clamp for securement. The step may adopt any shape but generally speaking will adopt a shape to conform to the leading edge of the beam. Since in most situations, the leading edge of the beam will be non-curved (eg square), the step will be a substantially perpendicular step. Preferably the outer end of the contact surface of the edge of either or both of the first and second jaw is chamfered.

This advantageously assists installation by providing a camming surface to assist the installer to manually bring the contact surfaces into contact with the upper and lower surface of the structural element (eg by locating the clamp adjacent the leading edge of the structural element and applying firm pressure).

The first jaw may further comprise a third aperture remote from the contact surface. For example, where the first aperture is rearward of the contact surface the third aperture may be forwardly of the first aperture (eg near to its leading end) and adapted to receive a first elongate fastener. For example, where the first aperture is forward of the contact surface (eg near to its leading end) the third aperture may be rearward of the first aperture and adapted to receive a first elongate fastener. The first elongate

-10 fastener may be used to further secure the clamp on the structural element.

The second jaw may further comprise a fourth aperture remote from the contact surface. For example, where the second aperture is rearward of the contact surface the fourth aperture may be forwardly of the second aperture (eg near to its leading end) and adapted to receive a second elongate fastener. For example, where the second aperture is forward of the contact surface (eg near to its leading end) the fourth aperture may be rearward of the second aperture and adapted to receive a second elongate fastener. The second elongate fastener may be used to further secure the clamp on the structural element.

Suitable first and second elongate fasteners are generally threaded fasteners (eg bolts) which are fastened with one or more (eg two) nuts.

The first, second, third and fourth apertures may be any suitable shape such as round, square, pyramidal, rectangular and may be slotted.

Preferably the clamp of the invention will be made from a springy material which will assist the installer to manipulate the jaws. Typically, the clamp of the invention will be made from mild steel which is optionally electro-zinc plated. More generally, the choice of material and dimensions appropriate for the purpose will be readily apparent to the skilled man.

Viewed from a further aspect the present invention provides a clamping assembly for suspending a utility component from a structural element comprising: a clamp as hereinbefore defined;

-11 a suspension element insertable through the first aperture of the first jaw and fastenable to the first jaw so that the clamp is securable to the structural element, whereby the utility component is suspendable from the suspension element.

Viewed from a yet further aspect the present invention provides a method for suspending a utility component from a beam comprising the steps of: locating a leading edge of the beam within the first and second jaws of a clamp as hereinbefore defined; bringing the contact surfaces of the first and second jaw into contact with the lower and upper surface of the beam; inserting a suspension element through the first aperture in the first jaw; fastening the suspension element to the first jaw; optionally inserting the suspension element through the second aperture in the second jaw and fastening the suspension element to the second jaw, whereby the clamp is secured to the beam; and suspending the utility component from the suspension element.

Viewed from a yet still further aspect the present invention provides a method for securing a grating to supporting metalwork comprising the steps of: locating adjacent bars of the grating and a portion of the supporting metalwork within the first and second jaws of a clamp as hereinbefore defined; bringing the contact surface of the first jaw into contact with the lower surface of the portion of supporting metalwork and the contact surface of the second jaw into contact with the upper surface of the adjacent bars; inserting a fastener through the second aperture in the second jaw and the first aperture in the first jaw; and

-12 fastening the fastener to the first jaw and the second jaw, whereby the clamp is secured to the grating.

Viewed from an even further aspect the present invention provides a process for manufacturing a clamp as hereinbefore defined comprising the steps of: (A) subjecting to simultaneous profiling steps, successive individualisable portions of a plate moving continuously between a first end and a second end of a press; and (B) individualizing clamps as hereinbefore defined from the profiled individualisable portions of the plate at the second end of the press.

The process advantageously involves minimum operator intervention and leads to continuous manufacture of the clamps from the plate.

The profiling steps may include raising, punching, cutting, shaving, folding or bending the plate.

Typically the tooling of the press is adapted to perform a plurality of profiling steps in a single stroke (he as it moves from top to bottom).

Preferably step (A) includes: subjecting to simultaneous punching and cutting steps respectively, adjacent individualisable portions of the plate moving continuously between a first end and a second end of the press.

Preferably step (A) includes: subjecting to simultaneous first and second folding steps respectively, adjacent individualisable portions of the plate moving continuously between a first end and a second end of the press.

-13 The press is typically a power press such as a die press. The plate is typically fed into the press in slit coil form.

Preferably the plate is a single train of successive individualisable portions.

Step (B) is typically carried out by cutting.

It is of further patentable significance that even without having been subjected to the process of the invention a blank of a profile foldable directly into a clamp as hereinbefore defined is useful per se.

Viewed from an even still further aspect the present invention provides a blank foldable into a clamp as hereinbefore defined.

The blank per se is useful as a wall tie ( eg a concrete wall tie). In a preferred embodiment, the blank is obtainable from sheet metal by cutting (eg laser cutting). Cutting may provide the external profile and any number of apertures (if desired eg for a suspension element or fastener). Alternatively apertures may be provided in an additional punching step.

Preferably the blank is axially symmetrical. Preferably the blank is substantially dog bone shaped. Preferably the plate is raised at its axis of symmetry.

The invention will now be described in a non-limitative sense with reference to accompanying Figures 2 to 11 in which:

-14 Figure 2 illustrates the results of a test carried out on a prototype embodiment of the clamp of the invention using the test rig illustrated in Figure 3; Figure 4 illustrates the results of a test carried out on embodiments of the clamp of the invention compared with conventional clamps) Figures 5a to e illustrate various views of embodiments of the clamp of the invention; Figure 6 illustrates a blank of the invention which may be folded into the embodiment of the clamp of the invention illustrated in Figure 5di Figures 7a and 7b illustrate (in end and side view) an embodiment of the clamp of the invention in use; Figure 8 illustrates a blank of the invention which may be folded into the embodiment of the clamp of the invention illustrated in Figure 7; Figure 9 illustrates schematically and in isolation the vertical displacement of the jaws of the embodiment of Figure 5; Figure 10 illustrates an embodiment of the clamp of the invention; and Figure 11 illustrates an embodiment of the clamp of the invention. Prototype Testing A test was carried out to determine the tensile load for a prototype embodiment of the clamp of the invention using the protocol described below. The prototype clamp used an M10 drop rod. The aim of the test was to establish whether the prototype clamp would meet the Vds approval criteria.

The test was set up on a horizontal test rig (see reference numeral 1 in Figure 3) using a two tonne load cell 2 (as the load capabilities were not expected to exceed two tonnes).

-15 The remainder of the test rig 1 includes standard hand pump 5 and six tonne hydraulic cylinder 6. A prototype clamp 3 with drop rod 10 was attached to the test rig 1 by means of a mild steel plate 11 (clamping thickness 12mm) and tightened until the jaws were in contact with the plate and secure. The test was carried out to the Vds approval criteria and load was applied in increments of 50kg. Displacement readings were taken at each increment by transducers 4A and 4B magnetically attached to the rigid frame of the test rig 1 and the average displacement calculated therefrom. Each transducer 4A and 4B has probes located on a plate 12 attached to the threaded drop rod 10 passing through the prototype clamp 3 to detect the movement of the prototype clamp 3 relative to the frame of the test rig 1.

Load|Displacement| Displacement Average I Observations (kg) A (mm) B (mm) _ Displacement _ 35.7 0 0 0 Pre Load (Vds) 50 0 0.04 0.02

100 0.02 0.13 0.075

150 0.06 0.23 0.145

200 0.11 0.32 0.215

250 0.15 0.41 0.28

300 0.20 0.50 0.35

357 0.27 0.64 0.455 Rated Load (Vds) 400 0.32 0.73 0.525

450 0.39 0.85 0.62

500 0.47 1.00 0.735

550 0.58 1.15 0.865

600 0.71 1.33 1.02

650 0.95 1.95 1.45

700 1.27 1.92 1.595

714 1.45 2.10 1.775 Minimum Breaking Load (Vds) 750 2.21 2.86 2.535

772 2.86 3.17 3.17 Ultimate load achieved

-16 The results of the test are shown in Figure 2. The ultimate load achieve was 772kg.

Comparative Testing In order to assess the load capabilities of the clamp of the invention relative to conventional clamps, a comparative test was performed as described above on the test rig illustrated in Figure 3 on the following: (1) a first embodiment of the clamp of the invention with an M8 threaded drop rod (hinged BC M08 rod); (2) a second embodiment of the clamp of the invention with tan M10 threaded drop rod (hinged BC M10 rod); (3) a standard FL1 clamp (a casting available from Lindapter International) with an M8 threaded drop rod; (4) a standard FL2 clamp (a casting available from Lindapter International) with an M10 threaded drop rod; and (5) an experimental pressed flange clamp which is capped and used with an M8 threaded drop rod.

It will be clearly seen from the results presented in Figure 4 that the performance of the first and second embodiments of the invention is superior to that of the conventional clamps.

Embodiments of the clamp of the invention are illustrated schematically in disassembled view in Figures 5a to e. In particular, a first embodiment of the clamp illustrated in Figures 5a (end view), 5b (side view) and 5c (top view) is designated generally by reference numeral 1. The clamp 1 comprises a first jaw 2 and a second jaw 3 connected by a connecting portion 4 incorporating a hinge 15. The connecting portion 4 adopts an angled shape. In use, the contact surface of edges 6 and 7 of the first jaw 2 and second jaw 3

-17 respectively contact lower and upper surfaces of a structural element such as a beam.

The first jaw 2 and second jaw 3 each comprise a U-shaped channel member with an open leading end 8 and 9 respectively.

The hinge 15 takes the form of two U-shaped cuts 15a and 15b on opposing edges of the connecting portion 4 whose tail ends are chamfered (see for example 15c). The depth of the U-

shaped cuts 15a and 15b are such that the first jaw 2 and second jaw 3 are rendered manually manipulable to assist installation. Each contact edge 6 or 7 is provided with a plurality of n-

shaped teeth lea and lob which serve to grip the lower and upper surface of the structural element.

The convex nature of the connecting portion 4 is such that a useful hollow 11 is created between the trailing ends 2a and 3a of the first jaw 2 and second jaw 3 respectively and the connecting portion 4. This may be used to horizontally suspend conduits or pipes. For example, a conventional cable guide or gland may be inserted into hollow 11 for feeding the conduits or pipes more securely.

The junctions of the connecting portion 4 with the first jaw 2 and second jaw 3 respectively constitute secondary hinges 4a and 4b. This renders the clamp 1 more manipulable and able to be secured successfully to horizontal or tapered surfaces. The second jaw 3 is provided with an aperture 12 collinear with an aperture in the first jaw 2 (not shown). Each aperture is capable of receiving a suspension element (not shown) such as a drop rod which may be fastened to the first

-18 aw (eg using nuts) in order to secure the clamp 1 to the structural element.

Figure 5d illustrates in side view an alternative embodiment which is largely the same as that illustrated in Figures 5a to c with the exception that contact edges 6 and 7 are provided near to their inner end 6a and 7a respectively with a perpendicular step 20a and 20b. Additionally, the front end 6b and 7b of the contact edge 6 and 7 respectively is chamfered. Both of these additional features serve to assist the operator in installing the clamp. In Figure be, there is illustrated a further alternative embodiment which

is largely the same as that illustrated in Figures 5a to c but in which the connecting portion 4 adopts a C-shape.

Figure 6 illustrates an embodiment of the blank of the invention 61 of a precut shape capable of being raised into the embodiment of the clamp of the invention illustrated in Figure 5d. The precut shape of blank 61 is such that there are U-shaped cuts 62a and 62b with chamfered tail ends extending into the opposing edges of the connecting portion 63 which taper outwardly into secondary hinges 64a and 64b at the junction of the connecting portion 63 and first and second jaws 65 and 66. As well as including first and second apertures 67a and 67b for receiving the suspension element, the blank 61 incorporates third and fourth apertures 67c and 67d which in use may be used to receive an elongate fastener for further securing the clamp to the structural component.

An alternative embodiment of the clamp of the invention is illustrated in Figures 7a and 7b and is designated generally by reference numeral 71. The clamp 71 comprises a first jaw 72 and a second jaw 73 connected by a connecting portion 74

-19 incorporating a hinge 75. The connecting portion 74 adopts an angled shape. In use, the contact surface of the edge 76 of the first jaw 72 contacts a lower surface of supporting metalwork 750 and the contact surface 711 of the roof of the second jaw 71 contacts upper surfaces of adjacent bars 712a and 712b of the grating 700.

The first jaw 72 and second jaw 73 each comprise a U-shaped channel member with an open leading end 78 and 79 respectively. The second jaw 73 is wider than the distance between adjacent bars 712a and 712b of the grating 700 and wider than the first jaw 72. The hinge 75 takes the form of two U-shaped cuts 75a and 75b on opposing edges of the connecting portion 74 whose tail ends are chamfered (see for example 715c). The depth of the U-shaped cuts 75a and 75b are such that the first jaw 72 and second jaw 73 are rendered manually manipulable to assist installation.

The contact edge 76 is provided with a plurality of e-shaped teeth 710a which serve to grip the lower surface of the supporting metalwork 750.

The junctions of the connecting portion 74 with the first jaw 72 and second jaw 73 respectively constitute secondary hinges 74a and 74b. This renders the clamp 71 more manipulable and able to secure the grating 700 more successfully.

The second jaw 73 is provided with an aperture 721 collinear with an aperture 722 in the first jaw 72 (shown in profile in Figure 7a). Each aperture 721 and 722 is capable of receiving a fastener.

Figure 8 illustrates a blank 81 of a precut shape capable of being raised into the embodiment of the clamp of the invention illustrated in Figure 7a and 7b. The precut shape

-20 of blank 81 is such that there are U-shaped cuts 82a and 82b with chamfered tail ends extending into the opposing edges of the connecting portion 83 which taper outwardly into secondary hinges 84a and 84b at the junction of the connecting portion 83 and first and second jaws 85 and 86.

The blank 81 includes first and second apertures 87a and 87b for receiving the fastener.

Figure 9 illustrates schematically and in isolation the relative vertical displacement of the hinge 15 and secondary hinges 4a and 4b of the embodiment of Figure 5 which causes them to close in a substantially parallel manner. This permits the hinge to adjust securely to structural elements of decreasing thickness and variable shape.

Figure 10 illustrates in perspective view an alternative embodiment which is largely the same as that illustrated in Figures 5a to c with the exception that (1) the hinge 15 is not undercut from the connecting portion 4, (2) the connecting portion 4 is not tapered into the second jaw 3 and (3) the second jaw 3 is wider than the first jaw 2.

Figure 11 is an embodiment of the clamp of the invention which is largely the same as that illustrated in Figures 5a to c but which is made from a lighter gauge material specifically for use in suspending lightweight utility components. Thus the connecting portion 4 is fitted with a cable clip 900 using a fastener such as a pin, screw or bolt through aperture 901. Such an arrangement can be used to support horizontally a bundle of cables 902. A similar cable clip 903 may be fitted between the second jaw 3 and connecting portion 4. A similar cable clip 905 may be fitted on the second jaw 3. Additional slots 904a and 904b are provided for suspending other utility components.

-21 An M6 drop rod 906 suspended from near to the leading end of first jaw 2 is used to suspend a cable tray 907. Rearwardly of the drop rod 906, the clamp is fastened by a threaded fastener 920 (shown cut away for clarity) having a cup square head, a round shank and a wing nut which passes through apertures in the first jaw 2 and second jaw 3.

Claims

-22 CLAIMS

1. A clamp comprising: a first jaw and a second jaw connected rearwardly by a connecting portion incorporating a hinge, wherein the first jaw and second jaw have opposing contact surfaces which in use contact the lower surface and upper surface respectively of a structural element, wherein the first jaw incorporates a first aperture remote from the contact surface and is adapted to receive a suspension element or fastener.

2. A clamp as claimed in claim 1 wherein the second jaw incorporates a second aperture substantially collinear with the first aperture, wherein the first and second aperture are adapted to receive the suspension element or fastener.

3. A clamp as claimed in claim 1 or 2 wherein each of the first jaw and second jaw comprises a reentrant body extending rearwardly into the connecting portion incorporating the hinge.

4. A clamp as claimed in claim 3 wherein each of the first jaw and second jaw comprises a substantially U-shaped channel member, the floor of which extends rearwardly into the connecting portion incorporating the hinge.

5. A clamp as claimed in any preceding claim wherein the junction of the first jaw and connecting portion incorporating the hinge constitutes a secondary hinge.

6. A clamp as claimed in any preceding claim wherein the junction of the second jaw and connecting portion incorporating the hinge constitutes a secondary hinge.

-23

7. A clamp as claimed in any preceding claim wherein the junction of the first jaw and connecting portion incorporating the hinge constitutes a first secondary hinge and the junction of the second jaw and connecting portion incorporating the hinge constitutes a second secondary hinge.

8. A clamp as claimed in claim 7 wherein the interaction of the hinge and secondary hinges causes the first and second jaw to close in a substantially parallel manner.

9. A clamp as claimed in any of claims 5 to 8 wherein the opposing edges of the connecting portion incorporating the hinge taper outwardly from the hinge to the (or each) secondary hinge.

10. A clamp as claimed in any preceding claim wherein the connecting portion incorporating the hinge is convex.

11. A clamp as claimed in claim 10 wherein the connecting portion incorporating the hinge adopts a substantially arcuate shape or an angled shape.

12. A clamp as claimed in either claim 10 or 11 wherein the trailing end of the first and/or second jaw are inwardly tapered.

13. A clamp as claimed in any preceding claim wherein the connecting portion incorporates a weakened region which acts as the hinge.

14. A clamp as claimed in claim 13 wherein the weakened region is an undercut.

-24

15. A clamp as claimed in claim 14 wherein the undercut comprises substantially U-shaped cuts on opposing edges of the connecting portion.

16. A clamp as claimed in claim 15 wherein the tail end of each of the substantially U-shaped cuts on opposing edges of the connecting portion is chamfered.

17. A clamp as claimed in any of claims 13 to 16 wherein the weakened portion is undercut to an extent sufficient to render the jaws manually manipulable.

18. A clamp as claimed in any preceding claim wherein the whole or a portion of the contact surface of the edge of either or both of the first and second jaw is toothed.

19. A clamp as claimed in any preceding claim wherein the contact surface of the edge of either or both of the first and second jaw is provided at or near to its inner end with a step which in use abuts a surface of the structural element.

20. A clamp as claimed in any preceding claim wherein the outer end of the contact surface of the edge of either or both of the first and second jaw is chamfered.

21. A clamp as claimed in any preceding claim wherein the first jaw further comprises a third aperture remote from the contact surface.

22. A clamp as claimed in claim 21 wherein the first aperture is rearward of the contact surface and the third aperture is forward of the first aperture and adapted to receive a first elongate fastener.

-25

23. A clamp as claimed in claim 21 wherein the first aperture is forward of the contact surface and the third aperture is rearward of the first aperture and adapted to receive a first elongate fastener.

24. A clamp as claimed in any of claims 21 to 23 wherein the second jaw further comprises a fourth aperture remote from the contact surface.

25. A clamp as claimed in claim 24 wherein the second aperture is rearward of the contact surface and the fourth aperture is forward of the second aperture and adapted to receive a second elongate fastener.

26. A clamp as claimed in claim 24 wherein the second aperture is forward of the contact surface and the fourth aperture is rearward of the second aperture and adapted to receive a second elongate fastener.

27. A clamping assembly for suspending a utility component from a structural element comprising: a clamp as defined in any preceding claim; a suspension element insertable through the first aperture of the first jaw and fastenable to the first jaw so that the clamp is securable to the structural element, whereby the utility component is suspendable from the suspension element.

28. A method for suspending a utility component from a beam comprising the steps of: locating a leading edge of the beam within the first and second jaws of a clamp as defined in any of claims 1 to 26; bringing the contact surfaces of the first and second jaw into contact with the lower and upper surface of the beam;

-26 inserting a suspension element through the first aperture in the first jaw; fastening the suspension element to the first jaw; optionally inserting the suspension element through the second aperture in the second jaw and fastening the suspension element to the second jaw, whereby the clamp is secured to the beam; and suspending the utility component from the suspension element.

29. A method for securing a grating to supporting metalwork comprising the steps of: locating adjacent bars of the grating and a portion of the supporting metalwork within the first and second jaws of a clamp as defined in any of claims 1 to 26; bringing the contact surface of the first jaw into contact with the lower surface of the portion of supporting metalwork and the contact surface of the second jaw into contact with the upper surface of the adjacent bars; inserting a fastener through the second aperture in the second jaw and the first aperture in the first jaw; and fastening the fastener to the first jaw and the second jaw, whereby the clamp is secured to the grating.

30. A process for manufacturing a clamp as defined in any of claims 1 to 26 comprising the steps of: (A) subjecting to simultaneous profiling steps, successive individualisable portions of a plate moving continuously between a first end and a second end of a press; and (B) individualizing clamps as defined in any of claims 1 to 26 from the profiled individualisable portions of the plate at the second end of the press.

31. A process as claimed in claim 30 wherein step (A) includes:

-27 subjecting to simultaneous punching and cutting steps respectively, adjacent individualisable portions of the plate moving continuously between a first end and a second end of the press.

32. A process as claimed in claim 30 or 31 wherein step (A) includes: subjecting to simultaneous first and second folding steps respectively, adjacent individualisable portions of the plate moving continuously between a first end and a second end of the press.

33. A process as claimed in any of claims 30 to 32 wherein the plate is a single train of successive individualisable portions.

34. A process as claimed in any of claims 30 to 33 wherein step (B) is carried out by cutting.

35. A blank foldable into a clamp as defined in any of claims 1 to 26.

36. A blank as claimed in claim 35 being substantially dog bone shaped.

37. A plate as claimed in either of claims 35 and 36 being raised at its axis of symmetry.