WO2013104889A2

WO2013104889A2 - Clamp assembly

Info

Publication number: WO2013104889A2
Application number: PCT/GB2013/000011
Authority: WO
Inventors: Philip Maurice Higgs; Matthew Jordan; Michael Carrington
Original assignee: Access Technologies Limited
Priority date: 2012-01-10
Filing date: 2013-01-10
Publication date: 2013-07-18
Also published as: GB201300401D0; GB201200352D0; GB2500087B; WO2013104889A3; GB2500087A

Abstract

A clamp assembly for use in securing together in a superimposed, non parallel relationship two elongate members (6,21) each having a pair of opposite edge regions (16,19) comprises four clamp units (1 ) each comprising upper and lower plate sections (3,4) and a connector section (7) which inter- connects the plate sections, said plate sections defining a gap (2) for accommodating the thickness of two superimposed flanges (5,20) of the elongate members, the upper plate section comprising a retention formation (8,9) whereby it may be secured to an upper plate section of another clamp unit in a manner in which the connector sections of two clamp units engage respective opposite edge regions (19) of a lower of the superimposed elongate members, the lower plate section comprising a retention formation (8,9) whereby it may be secured to the lower plate section of another clamp unit in a manner in which the connector sections of the two clamp units that are secured together at their lower plate sections have the connector sections thereof in engagement with respective opposite edge regions (16) of the upper of the superimposed elongate members, and in the clamp assembly the four clamp units being positioned at the four corners defined by the intersection of the superimposed elongate members, the upper plate sections adjacent each edge region of an upper of the elongate members being secured together by retention means (47) which extends between the two upper plate sections parallel with the longitudinal direction of the upper elongate member, and the lower plate sections of the two clamp units adjacent each edge region of the lower elongate member being secured together by retention means (47) which extends between the two lower plate sections parallel with the longitudinal direction of the lower elongate member.

Description

CLAMP ASSEMBLY

Field of the Invention

This invention relates to a clamp assembly for use in securing together two components and in particular, though not exclusively, for securing two structural type members, such as I - section beams, each having a pair of opposite edge regions. The invention relates in particular, though not exclusively, to a clamp assembly for use in securing together two said elongate members in a superimposed, non-parallel relationship.

The invention provides also a clamp unit for use as one of a set of four clamp units of a clamp assembly for securing together two elongate members in a superimposed non- parallel relationship.

Background of the Invention

For constructing a joint when erecting a steel gantry system the drawbacks of using pre- drilled holes and through bolts (costly and difficult slow to fit) have been long recognised.

A system that avoids the need for pre-drilled holes isalready known but is expensive, complex and also time consuming to fit. Typically, to complete one joint connecting one universal beam to another takes 25 separate items, as well as the need for a drilled, steel retaining plate that has to be placed between the beams. Notoriously the thickness of the interposed steel retaining plate is omitted on engineering drawings.

In an attempt to enable two girders to be assembled in a flush fit manner, i.e. to avoid the need for two girders to be separated by an interposed, pre-drilled, retaining plate, and to facilitate on-site adjustments it has been proposed to provide a beam fixing device comprising four clamping plates and four threaded fasteners.

An example of a fixing device of this type is described in more detail in the specification of International patent publication WO 9405918A1.

Although a beam fixing device as described in WO 9405918A1 facilitates a flush fitting structural inter-connection of two girders it does not lend itself to ease of on-site assembly. Thus the installer finds it necessary to hold two of the clamping plates in position with one hand whilst installing the threaded fasteners with the other hand.

Typically the four clamping plates are each in the form of steel forgings and provided with textured surfaces in an attempt to minimise any tendency for the adjacent plates to slide relative to one another during assembly. However the forged steel construction adds to the cost of manufacture.

Objective of the Present Invention

The present invention seeks to provide an improved clamp assembly, and a clamp unit for use in a clamp assembly for securing together two elongate members, such as two elongate plates or flanged girders, in a superimposed relationship in which the two members may be in direct contact with one another and wherein on-site assembly may be effected more readily than with many hitherto known devices.

Summary of Aspects of the Invention In accordance with one aspect of the present invention there is provided a clamp assembly for use in securing together in a superimposed, non parallel relationship two elongate members each having a pair of opposite edge regions, said clamp assembly comprising four clamp units, each clamp unit comprising upper and lower plate sections and a connector section which inter-connects the upper and lower plate sections, said plate sections defining therebetween a gap for accommodating the thickness of two superimposed edge regions of the elongate members, each clamp unit having an upper plate section comprising a retention formation whereby an upper plate section of a first clamp unit may be secured to an upper plate section of a second clamp unit in a manner in which the connector sections of the first and second clamp units engage respective opposite edge regions of a lower of the two superimposed elongate members, each clamp unit having a lower plate section comprising a retention formation whereby a lower plate section of a first clamp unit may be secured to the lower plate section of another of the clamp units and in a manner in which the connector sections of the two clamp units that are secured together at their lower plate sections have the connector sections thereof in engagement with respective opposite edge regions of the upper of the two superimposed elongate members, and in the clamp assembly the four clamp units being positioned respectively one each at the four corners defined by the intersection of the superimposed elongate members, the upper plate sections of the two clamp units adjacent each edge region of an upper of the elongate members being secured together by retention means which extends between the two upper plate sections in a direction substantially parallel with the longitudinal direction of the upper elongate member, and the lower plate sections of the two clamp units adjacent each edge region of the lower elongate member being secured together by retention means which extends between the two lower plate sections in a direction substantially parallel with the longitudinal direction of the lower elongate member.

Each clamp unit preferably comprises a casting but alternatively may comprise a molding or forging. Suitable materials include cast iron, steel, engineering grade plastics and composite materials such as fibre reinforced plastics.

The retention formation of each upper and lower plate section may be in the form of an aperture to receive the shank of a bolt whereby two plate sections may be clamped together. Optionally at least one of the apertures may be screw-threaded for engagement by a retention bolt.

The connector section of a clamp unit may be formed integrally with the upper and lower plate sections of the clamp unit.

Alternatively the connector section may be of the type which permits the upper and lower plate sections to be moved relative to one another, for example as considered in a direction parallel with the direction of the length of the connector section. The connector section may be defined at least in part by a bolt which extends through apertures in the upper and lower plate sections and which thereby allows the upper and lower plate sections to be pivoted relative to one another about a longitudinal axis defined by the longitudinal axis of the bolt.

The bolt may be provided in conjunction with spacer means, such as a tubular sleeve, which defines a spacing, for example a minimum spacing, of the confronting surfaces of the upper and lower plates sections.

In a further alternative the connector section may be of a type which enables the spacing of confronting surfaces of the upper and lower plate sections to be selectively varied or pre-selected, for example to equal the combined thickness of the superimposed edge regions which, in the assembly, are to lie between the upper and lower plate sections of the clamp unit. Irrespective of whether or not the connector section is formed integrally with the upper and lower plate sections, the connector section may serve to retain the upper and lower plate sections in a pre-determined relationship, typically superimposed relative to one another, as considered about an axis parallel with the direction in which confronting surfaces of the upper and lower plate sections are spaced apart.

The connector section may have a circular or other such cross-sectional shape which in the assembly makes line type contact with edges of each of the superimposed elongate members. Alternatively the connector section may be formed with at least one planar abutment face for face-to-face contact with at least one edge of the superimposed elongate members. The connector section may be formed with two substantially planar abutment faces and, particularly for use in forming a joint between two elongate members which are to extend perpendicular relative to one another, said abutment faces may be positioned othogonally relative to one another.

A clamp assembly of the present invention may be dimensioned for specific use with elongate members having edge regions of a specific thickness. However, to allow a clamp assembly to be used with elongate members having edge regions of different thicknesses, or for a spacer plate optionally to be provided between two superimposed elongate members, the clamp assembly may comprise thickness compensation means.

A thickness compensation means may be independent of the clamp units and may, for example, be in the form of a thickness compensator comprised by packing members, for example wedges or stepped inserts for positioning between confronting surfaces of a clamp unit plate section and elongate member. Alternatively thickness compensation means may be comprised by a thickness compensator secured to the clamp unit. The or each plate section may have a thickness compensator secured thereto and which may be positioned to bear against one or other of the two elongate members. Thus the thickness compensator of an upper plate section of a clamp unit may be positioned to bear against that elongate member which in the assembly is furthest from the lower plate section of the clamp unit, or it may bear against the elongate member which lies closest to the lower plate section. The thickness compensator may be in the form of a screw-threaded adjuster which engages with a screw-threaded aperture in one of the plate sections.

The retention formation for a retention means by which a plate section of one clamp unit may be secured to a plate section of another clamp unit may be in the form of a tab which is apertured to receive, in use, the shank of a connecting bolt. The aforedescribed thickness compensator which is secured to the clamp unit may locate in a screw-threaded aperture provided in the plate section at a position between the region of the plate section associated with the connector section and the position of the plate section associated with the tab.

Although the clamp assembly of the present invention may be employed for securing together two elongate members in a manner in which they are angled relative to one another without necessarily forming an orthogonal assembly, the invention is particularly applicable to forming an inter-connection between two elongate members, such as two l-section beams in a manner in which the beams extend perpendicular to one another.

In another aspect of the present invention, for forming an orthogonal assembly the present invention provides that each clamp unit of the clamp assembly may be in the form of a clip, for use in conjunction with three similar clips, to secure together two beams at a joint with one, upper beam seated on top of a lower beam, the clip comprising upper and lower plates and defining a gap between said upper and lower plates, the gap being of width to accommodate portions of the flanges of the beams, a connector piece connecting together the upper and lower plates at the required spacing to define the gap, and the upper plate, at an end thereof distal from the connector piece, terminating in an upwardly directed, orthogonal tab which is aperture to receive, in use, the shank of a connecting bolt common to an adjacent clip, and adapted to extend, in use, parallel to the longitudinal axis of the upper beam, the connector piece having two orthogonal abutment faces, whereby a portion of the edge of the lower flange of the upper beam engages one abutment face, and a portion of the edge of the upper flange of the lower beam engages the other abutment face, and with the lower plate at an end distal from the connector piece similarly terminating in a downwardly directed tab which is orthogonal to the first tab and is again aperture to receive the shank of a second bolt, for the latter to extend in a direction orthogonal to the first bolt and parallel to the longitudinal axis of the lower beam.

According to a further aspect of the invention, there is provided a joint between two orthogonal beams, one located on top of the other, comprising four clips in accordance with the preceding aspect of the invention, secured together by four bolts each provided with one of four locking nuts, to complete the joint.

Advantages of the Invention

The use of a clamp assembly and clamp unit in accordance with the present invention avoids the need for any drilled holes in the beams and attendant alignment problems and furthermore, in contrast to many prior art joints, requires a substantially reduced number of components - being four such clamp units (two being identical, and two being of opposite hand), four bolts, and four nuts/locking nuts i.e. 12 components, compared with the circa 25 needed for some prior art systems. In addition, for an orthogonal assembly the optional provision of the orthogonal abutment surfaces on the clamp unit connector section ensures that two elongate members, such as two beams may be firmly gripped, and securely held, at 90° to each other, the four clamp units together exerting both lateral and vertical forces, providing a further advantage over the prior art.

Furthermore, during installation the elongate members can, if necessary, be loosely connected initially i.e. with the nuts of the four bolts not fully tightened, allowing the clamp units, and possibly also the elongate members to be moved into correct position and/or finally checked before tightening.

It is to be noted that, from the practical and installation viewpoint, it is impossible for a steel erector to fit certain prior art systems using one hand. Because a joint commonly is required at an elevated position, there is an unavoidable risk that no hand is available to hold on to a ladder. In addition, a typical prior art system may require 37 separate items per joint, all of which need to be collected, held, and positioned and fitted in correct order, and tightened correctly, requiring a push or pull on a torque wrench. If the erector is standing on a platform ladder or scissor lift, tightening exerts an opposite, destabilizing force on the platform or scissor lift. In contrast, for a typical installation of horizontally extending beams, the clamp unit in accordance with the invention is tightened in a horizontal plane with the erector pulling downwardly and hence is safer when at an elevated position.

In use to form an orthogonal assembly, and employing clamp units each having an adjustment screw to enable them to be fitted to a range of beam thicknesses, the clamp units are secured to the lower flange of the upper beam and onto the upper flange of the lower universal beam to bring abutment surfaces of each clamp unit connector section into contact with edges of two elongate members. Four securing bolts are then passed through the co-axial holes of adjacent clamp unit retention formations, so that the axes of one pair of bolts are parallel to the longitudinal axis of one universal beam, whilst the longitudinal axes of the other pair of bolts are orthogonal and parallel to the longitudinal axes of the other universal beam.

Brief Description of the Drawings

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying diagrammatic drawings in which :-

Figure 1 is a perspective view of a joint between two orthogonal universal beams, one seated on the other, using four clamp assembly clips in accordance with the invention;

Figure 2 is a view in the direction of arrow A of Figure 1 ;

Figure 3 is a view in the direction of arrow B of Figure 1 ; Figure 4 is a perspective view of part of another clamp assembly and clamp unit in accordance with the present invention in use to join two beams;

Figure 5 is an end view in the direction of the arrow C of Figure 4;

Figure 6 is an end view in the direction of the arrow D of Figure 4;

Figure 7 is a perspective view of part of a clamp assembly and clamp unit in accordance with another embodiment of the present invention in use to join two beams, and

Figure 8 is a perspective view of a clamp unit of a clamp assembly in accordance with yet another embodiment of the present invention.

Detailed Description of the Drawings In a first embodiment of the invention (see Figures 1 to 3), each clamp unit is in the form of a cast iron clip 1 which defines a gap 2 between upper and lower plates 3,4, the gap 2 being of width to accommodate as a close fit a portion of lower flange 5 of an upper universal beam 6 and an upper flange 20 of a lower beam 21. An integrally formed connector piece 7 connects together the upper and lower plates 3,4 at the required spacing to define the flange receiving gap 2.

The upper plate 3 at an end distal from the connector piece 7 terminates in an upwardly directed orthogonal tab 8 which is apertured at 9 to receive, in use, a shank of a connecting bolt (not shown) common to an adjacent clip, and adapted to extend, in use, parallel to the longitudinal axis 12 of the upper universal beam 6. In addition, the connector piece has two orthogonal abutment faces 13,14, whereby a portion of the edge 16 of the lower flange 5 of the upper universal beam 6 engages the abutment face 13, and a portion of the edge 19 of the upper flange 20 of the lower universal beam 21 engages the other abutment face 14. The lower plate 4 at an end distal from the connector piece 7 similarly terminates in a downwardly directed tab 27 which is orthogonal to the first tab 8 and is apertured at 23 to receive the shank of a second bolt (not shown), for the latter to extend in a direction orthogonal to the first bolt 11 and parallel to the longitudinal axis 26 of the lower universal beam 21. Locking nuts (not shown) are applied to the bolts.

To form an orthogonal joint at a crossover between the two universal beams 6 and 21, four clips 1 (two left hand clips and two right hand clips) are employed, the gaps 2 approximating to the thickness of the flanges 5, 20, so that the clips 1 may be pushed or tapped into position, and then the bolts and nuts fitted.

In a second embodiment of the present invention (see Figures 4 to 6) a clamp assembly 30 for forming a joint between two orthogonal beams comprises four clamp units 3 , 32, two of the units 31 being of an opposite hand to the other two units 32.

Each clamp unit 31, 32 is formed as a metal casting and comprises an upper plate section 33, a lower plate section 34 and a connector section 35 which is formed integrally with the plate sections.

The plate sections define confronting surfaces 36, 37 which are spaced apart to provide a gap 40 for accommodating the superimposed edge regions 38, 39 of two beams 41, 42 that are to be connected by the clamp assembly.

The upper and lower plate sections are substantially similar except that the upper plate section is provided with a screw-threaded aperture 46 that extends parallel with the length of the connector section and locates a thickness compensation screw 43 whereby, when using the clamp unit to secure together two superimposed beam edge regions that have a thickness less than the spacing of the confronting plate surfaces 36, 37, the clamp unit may be secured in position by tightening the screw to bear against one of the beam surfaces.

Each plate section is formed integrally with an upstanding tab section 44 which is formed with an aperture 45 whereby the aligned apertures of two confronting tab sections of two clamp units forming the clamp assembly may be bolted together.

As considered about an axis parallel with the longitudinal direction of the connector section 35, the aperture 45 of one plate section 33 extends perpendicularly relative to the aperture of the other plate section 34. For forming a joint between the two beams 1, 42 two of the clamp units 31 of one hand are positioned at two opposite comer regions of the four comer regions defined by the edge regions of the two superimposed beams. The two clamp units 32 of the other hand are positioned at the other two comer regions. Each clamp unit conveniently is retained in position by lightly tightening the thickness compensation screw 43 of each clamp unit. Retention bolts 47 are then provided to extend between and, upon tightening, urge together the confronting tab sections 44 of the clamp units 31 , 32, and the thickness compensation screws 43 may be further tightened for additional integrity of the resulting joint. Accordingly, in the final assembly the respective abutment surfaces 48, 49 of each clamp unit connector section 35 bear firmly against an edge region of a respective one of the two beams and, in co-operation with the force exerted by the thickness compensation screws, the two beams are securely held relative to one another.

In a third embodiment of the present invention (see Figure 7) a clamp assembly is formed by using a clamp 50 of a modified construction as compared with that of the second embodiment. Each clamp unit 50 comprises a pair of plate sections 51 , 52 having tab sections 53 which are apertured each for receiving a retention bolt 54 whereby the clamp units may be bolted together. However, the clamp units differ from those of the second embodiment in that they do not comprise integrally formed connector sections. Instead the plate sections are inter-connected by nut and bolt assemblies 55 which enable the tab sections of the respective upper and lower plate sections to be angled relative to one another, thereby facilitating use of the clamp units for forming a joint between two elongate members which do not necessarily extend perpendicularly relative to one another.

A further difference between the clamp unit of this embodiment invention and that of the second embodiment is that each plate section for confronting the surface of a beam has an auxiliary region 56 which extend sideways, away from the beam confronted by the plate section, to lie over the other beam of the assembly. That auxiliary region 56 is provided with a thickness compensation screw 57. In consequence, by adjustment of the compensation screw 57, it can be ensured that each plate section of each clamp unit presents to the nut and bolt of the connector section 55 a bearing surface which is substantially co-planar with confronting surfaces of the bolt head and nut.

For forming a joint between two beams and employing the clamp units of this embodiment of the present invention, each clamp unit is initially secured in a respective one of the four comers of the intersecting beams by lightly tightening the connector section bolt 55. The thickness compensation screws 57 can then be finally adjusted to ensure that the plate sections 51,52 provide bearing surfaces that are substantially co-planar with the confronting surfaces of the bolt head and nut prior to tightening of the retention bolts 54 and the final tightening of the connector section bolts 55.

In a fourth embodiment of the present invention (see Figure 8) a clamp assembly comprises four clamp units 60 which are each of a two part construction and comprise a connector section which prevents relative rotation of the plate sections about a

longitudinal axis of the connector section whilst allowing a variation in the spacing of confronting surfaces of the plate sections so as to define therebetween a variable gap for accommodating a pair of beam flanges or the like of different combined thicknesses. Two of the clamp units are handed opposite to the other two clamp units

The clamp unit 60 comprises two identical parts 61 each having a tab section 62 which is formed with an aperture 63 whereby, in use, a bolt may be fitted through the aperture and that of a confronting tab section of an oppositely handed clamp unit to urge the two clamp units towards one another in a manner substantially as described in respect of the preceding embodiment of the invention.

Each clamp part has a plate section 64 which, at a position distal from the tab section, is formed with an aperture 65 whereby a bolt may be fitted through the two apertures of the pair of clamp parts thereby to serve as a connector section and to enable the two parts to be drawn towards one another by tightening of the bolt and an associated nut.

A part 66 of the plate section 64 which defines the aperture 65 is of an enlarged thickness and defines a pair of orthogonal abutment surfaces 67, 68. In use one of the abutment surfaces of one clamp part will abut an edge of one beam and one of the abutment surfaces of the other clamp part will abut an edge of the other of the two beams that are being joined together in a superimposed manner.

To assist in achieving an orthogonal joint between two beams each part 66 is formed with an aperture and a peg 69 whereby in the assembly each peg of each clamp part locates in an aperture 70 of the other clamp part and thereby serves to prevent relative rotation of the two parts about a longitudinal axis of the connection bolt extending through the apertures 65.

From the foregoing it will be understood that contrast with the substantial number of components required in respect of prior art systems, or the requirement for a carefully pre- drilled and interposed retention plate, the clamp assembly of the present invention merely comprises four clamp units and a requirement for inter-connecting nut and bolt units, with the further advantage that each clamp unit can readily be initially positioned and independently secured to the beams.

KKL61DE4.

Claims

Claims.

1. A clamp assembly for use in securing together in a superimposed, non parallel relationship two elongate members each having a pair of opposite edge regions, said clamp assembly comprising four clamp units, each clamp unit comprising upper and lower plate sections and a connector section which inter-connects the upper and lower plate sections, said plate sections defining therebetween a gap for accommodating the thickness of two superimposed edge regions of the elongate members, each clamp unit having an upper plate section comprising a retention formation whereby an upper plate section of a first clamp unit may be secured to an upper plate section of a second clamp unit in a manner in which the connector sections of the first and second clamp units engage respective opposite edge regions of a lower of the two superimposed elongate members, each clamp unit having a lower plate section comprising a retention formation whereby a lower plate section of a first clamp unit may be secured to the lower plate section of another of the clamp units and in a manner in which the connector sections of the two clamp units that are secured together at their lower plate sections have the connector sections thereof in engagement with respective opposite edge regions of the upper of the two superimposed elongate members, and in the clamp assembly the four clamp units being positioned respectively one each at the four corners defined by the intersection of the superimposed elongate members, the upper plate sections of the two clamp units adjacent each edge region of an upper of the elongate members being secured together by retention means which extends between the two upper plate sections in a direction substantially parallel with the longitudinal direction of the upper elongate member, and the lower plate sections of the two clamp units adjacent each edge region of the lower elongate member being secured together by retention means which extends between the two lower plate sections in a direction substantially parallel with the longitudinal direction of the lower elongate member.

2. A clamp assembly according to claim 1 wherein at least one the clamp units comprises a thickness compensator whereby the clamp assembly may be used with elongate members having superimposed edge regions of different combined thicknesses.

3. A clamp assembly according to claim 2 wherein the thickness

compensator is secured to a plate section and is adjustable to bear against that elongate member surface which confronts the plate section.

4. A clamp assembly according to claim 2 wherein the thickness

compensator is secured to an auxiliary portion of the plate section and is adjustable to bear against the elongate member which lies closest to the lower plate section of the clamp unit.

5. A clamp assembly according to any one of claims 2 to 4 wherein the thickness compensator comprises a screw-threaded adjuster which engages with a screw-threaded aperture in one of the plate sections of the clamp unit.

6. A clamp assembly according to any one of the preceding claims wherein at least one clamp unit comprises a pair of plate sections each comprising a retention formation in the form of an aperture through which a connecting bolt may extend whereby in use a connecting bolt may extend through aligned apertures of two retention formations of a pair of clamp units for securely connecting together plate sections of the two clamp units.

7. A clamp assembly according to any one of the preceding claims wherein the retention formation of each plate section of a clamp unit is in the form of a tab which extends upwards from the plate section at a position distal from the position at which the connector section connects with the plate section.

8. A clamp assembly according to any one of the preceding claims wherein at least one of the clamp units comprises a connector section which permits the upper and lower plate sections of the clamp unit to be moved relative to one another.

9. A clamp assembly according to claim 8 wherein the connector section permits the upper and lower plate sections to be moved relative to one another as considered in a direction parallel with the direction of the length of the connector section whereby the spacing of the upper and lower plate sections may be adjusted.

10. A clamp assembly according to claim 8 or claim 9 wherein the connector section permits the upper and lower plate sections to be pivoted relative to one another about a longitudinal axis defined by the longitudinal axis of the connector section.

11. A clamp assembly according to claim 8 or claim 9 wherein the connector section comprises a bolt which enables the two plate sections to be urged together to bear against interposed and superimposed sections of elongate members and additionally comprises an anti-rotation formation positioned offset relative to the bolt to prevent relative rotation of the two plate sections about the longitudinal axis of the bolt.

12. A clamp assembly according to any one of claims 1 to 7 wherein the clamp unit comprises a connector section formed integrally with each of the upper and lower plate sections of the clamp unit.

13. A clamp assembly according to any one of the preceding claims wherein the connector section has a cross-sectional shape which, when in use to interconnect two elongate members makes line contact with edges of each of the superimposed elongate members. 4. A clamp assembly according to any one of claims 1 to 12 wherein the connector section comprises at least one planar abutment face which, when in use to inter-connect two elongate members, makes face to face contact with an edge of each of the superimposed elongate members.

15. A clamp assembly according to claim 14 wherein the connector section of a clamp unit comprises two substantially planar abutment faces which, in use, permit face to face contact with respective edges of two superimposed elongate members secured together by the clamp assembly.

16. A clamp unit in the form of a clip, for use in conjunction with three similar clips, to secure together two beams at a joint with one, upper beam seated on top of a lower beam, the clip comprising upper and lower plates and defining a gap between said upper and lower plates, the gap being of width to accommodate portions of the flanges of the beams, a connector piece connecting together the upper and lower plates at the required spacing to define the gap, and the upper plate, at an end thereof distal from the connector piece, terminating in an upwardly directed, orthogonal tab which is aperture to receive, in use, a shank of a connecting bolt common to an adjacent clip, and adapted to extend, in use, parallel to the longitudinal axis of the upper beam, the connector piece having two orthogonal abutment faces, whereby a portion of the edge of the lower flange of the upper beam engages one abutment face, and a portion of the edge of the upper flange of the lower beam engages the other abutment face, and with the lower plate at an end distal from the connector piece similarly terminating in a downwardly directed tab which is orthogonal to the first tab and is again aperture to receive the shank of a second bolt, for the latter to extend in a direction orthogonal to the first bolt and parallel to the longitudinal axis of the lower beam.

17. A clamp assembly comprising four clips according to claim 16 and four bolts each provided with one of four locking nuts for effecting a joint between two orthogonal beams.

18. A clamp assembly according to any one of claims 1 to 15 or claim 17 in combination with packing members each for use in positioning between confronting surfaces of a clamp unit plate section and elongate member.

19. A clamp assembly or clamp unit according to any one of the preceding claims wherein a said clamp unit comprises cast material.

20. An assembly of two elongate members wherein said members are secured in a superimposed non-parallel relationship by means of a clamp assembly according to any one of claims 1 to 15 or any one of claims 17 to