BEAM FIXING DEVICE

Abstract: A fixing device for clamping together first and second overlapping plates (10, 11) having respective first and second pairs of opposed connecting edges (12, 13) which intersect at four corner regions (14), said fixing device being operative to clamp the second plate (11) to said connecting edges (12) of the first plate (10) and to clamp the first plate (10) to said connecting edges (13) of the second plate (11), and said fixing device comprising: a set of four elongate clamping plates (18) each positionable along a respective one of said connecting edges (12, 13) of one of said plates (10, 11) and of a length to project axially beyond the opposed connecting edges (12, 13) of the other of said plates (10, 11) whereby each end of each clamping plate (18) is positionable over a respective one of said corner regions (14); slots (19) formed through each clamping plate (18) and extending generally parallel to the axis thereof so as to overlie said corner region (14); and a set of four threaded fasteners (20) each being capable of being taken through a slot (19) of one clamping plate (18) at one corner region (14) and through a slot (19) of an underlying clamping plate (18) at the same corner region, each fastener being adjustable along the length of the respective slot until it reaches a required position in the respective corner region and then being tightenable in order to clamp the clamping plates together, whereby a respective threaded fastener is positionable and then tightenable at each corner region in order to clamp together the overlapping plates (10, 11) via the four clamping plates (18).

Description: BEAM FIXING DEVICE This invention relates to a fixing device for use in clamping together two overlapping plates, such as the bottom flange plate of an upper I-section beam and the top flange plate of a lower I-section beam extending under and supported from the upper beam. In the construction of buildings, it is often necessary to clamp together metal beams, which usually extend perpendicular to each other, and the clamping can be carried out by drilling through the overlapping flanges of the beams and then fitting threaded fasteners through aligned holes. Alternatively, if it is required to provide a fastening system which does not need any hole drilling to take place, it is known to use LINDAPTER (registered trade mark) fixings, which can be used to clamp together overlapping flange edges of two beams. LINDAPTER fixings have been used for many years for joining together flanged metal beams, and for other uses, and remain widely used by customers for many different fixing applications. An example of existing use of LINDAPTER fixings is shown in Figure 1 of the accompanying drawings, to which reference will now be made. This shows the use of threaded fastener clamps to join together overlapping I beams 50 and 51 , with the bottom flange 52 of beam 50 overlying the top flange 53 of beam 51 and extending perpendicular thereto. The fasteners are designated by reference 54, and each comprises bolt 55, nut 56 and a pair of opposed gripping saddles 57 which have ribbed gripping noses 58 to engage respective flange edges. However, as can be seen in Figure 1 , a feature of use of the fixings 54 to join together two overlapping flanged beams is the need for a separation plate 59 to be provided, sized according to the dimensions of the flanges of the overlapping beams, and which is positioned between the bottom flange 52 of the upper beam 50 and the top flange 53 of the lower beam 51. Further, the specially sized plate 59 also requires formation of drilled holes 60 at corner locations to suit the particular combination of flange plates to be joined together. This separation plate is an essential component of the known fixing system, in conjunction with suitable LINDAPTER type threaded fasteners. This has been, and still is acceptable to many customers, but can give rise to inconvenience during assembly on sites which have a number of different beam profiles, and which overlap at certain positions on site, in that the plates have to be manufactured for each individual application and the assemblers will have to make sure that an appropriate separation plate is used at each beam overlapping position, and time is involved in the selection of the appropriate separation plates for any particular location, and further time can be involved in reselecting separation plates when a wrong selection has been made, and all of which add to labour costs in the assembly operation, in addition to the cost of the fixings and plates themselves. Accordingly, a need is now becoming recognised for a fixing device which can be used to clamp together two overlapping plates, and more particularly overlapping flange plates of one beam overlying another beam, and which is readily adjustable for use with different widths of flange plate, so as to provide economies in labour costs of assembly of overlapping beams on site. This need is being recognised particularly in factories into which conveyor systems are to be installed e.g. car assembly lines, where there are many locations at which different sized support beams intersect and require to be clamped together at such intersections. According to the invention there is provided a fixing device for clamping together first and second overlapping plates having respective first and second pairs of opposed connecting edges which intersect at four corner regions, said fixing device being operative to clamp the second plate to said connecting edges of the first plate and to clamp the first plate to said connecting edges of the second plate, and said fixing device comprising: a set of four elongate clamping plates each positionable along a respective one of said connecting edges of one of said plates and of a length to project axially beyond the opposed connecting edges of the other of said plates whereby each end of each clamping plate is positionable over a respective one of said corner regions; slots formed through each clamping plate and extending generally parallel to the axis thereof so as to overlie said corner region; and, a set of four threaded fasteners each being capable of being taken through a slot of one clamping plate at one corner region and through a slot of an underlying clamping plate at the same corner region, each fastener being adjustable along the length of the respective slot until it reaches a required position in the respective corner region and then being tightenable in order to clamp the clamping plates together, whereby a respective threaded fastener is positionable and then tightenable at each corner region in order to clamp together the overlapping plates via the four clamping plates. The invention therefore provides a fixing device which is adjustable to suit different widths of overlapping plates (width being measured between opposed connecting edges), and which therefore can readily be operated on site to meet differing requirements. The fixing device of the invention is therefore "universal" in the sense that a common design can be utilised with a range of plate widths. A particularly preferred arrangement of overlapping plates to be clamped together by a fixing device of the invention comprises an overlapping arrangement of flanged beams, such as I-beams. When the overlapping beams intersect at right angles to each other, the four corner regions at which the threaded fasteners are located will be at the corners of a rectangular area. However, it is not essential to the invention for the beams to intersect at right angles to each other, and they may be arranged skewed, in which case the area of overlap will be a parallelogram. The fixing device of the invention is just as capable of clamping together two overlapping plates in such an arrangement. During assembly, each threaded fastener will be adjusted along the length of a respective slot until the fastener projects downwardly closely adjacent to an underlying connecting edge, and is then tightened up. To provide a clamp assembly which is resistant to possible loosening by vibration, which may occur when a supporting structure of beams is used to support conveyor systems, it is preferred that there are surrounding gripping formations arranged alongside each slot, and engageable by clamping elements forming part of the threaded fasteners, and which, upon tightening, make gripping engagement and thereby resist any tendency for the fasteners to move thereafter along the length of the respective slot. The threaded fasteners preferably include "washers" which fit around the threaded shanks of the fasteners, and each of which can make gripping ' engagement with gripping portions along the slots of the clamping plates. A fixing device according to the invention is particularly suitable for joining together the flanges of beams having flange thicknesses which are approximately constant throughout their width, but this is not essential to the invention. A fixing device according to the invention can be used also to clamp together flanged I-beams of tapering flange thicknesses as used particularly on the US market, provided that the threaded fasteners are located closely adjacent to each corner region, and with sufficient overlap of the clamping faces of the clamping plates which engage the flange edges, so that a rigid and shake proof clamped assembly can be obtained. For economies of manufacture, it will be preferred that each clamping plate in the set of clamping plates for each fixing device of the invention may be of identical design. However, this is not essential to the invention, provided that each clamping plate fulfils the requirements of the fixing device of the invention as defined above. One embodiment of fixing device according to the invention will now be described in detail, by way of example only, with reference to the accompanying drawings, in which: Figure 2 is a diagrammatic illustration of two overlapping plates which can be coupled together by a fixing device according to the invention; Figure 3 is a side view showing part of a preferred embodiment of fixing device according to the invention, being used to join together the flange plates of two overlying I- section beams; Figure 4 is a plan view of one of a set of four coupling plates forming part of the fixing device of the invention; Figures 5a to 5c are, respectively, plan, side and end detail views of a washer type clamping element for use with each of a set of four threaded fasteners also forming part of the fixing device of the invention; and Figure 6 is a view, similar to Figure 3, of a modified embodiment of the invention. Referring first to Figure 2 of the drawings, this is a schematic illustration of first and second overlapping plates which can be clamped together by a fixing device according to the invention, and these plates may comprise, for example, a bottom flange of an upper I-section beam, and a top flange of a lower I-section beam which overlap at a perpendicular point of intersection between them. The first and second overlapping plates are designated by references 10 and 11 , and first plate 10 has a first pair of opposed connecting edges 12, and second plate 11 has opposed connecting edges 13. The connecting edges 12 and 13 intersect at right angles at four corner regions 14, and it is at these corner regions, as will be described in more detail below, at which threaded fasteners are positioned in order to clamp together the overlapping plates. The embodiment of fixing device according to the invention comprises a set of four elongate clamping plates which will be described in more detail below with reference to Figure 3, and each clamping plate can be positioned along a respective one of the connecting edges of one of the plates e.g. along connecting edge 12 of first plate 10, and will be of a length sufficient to project axially beyond the opposed connecting edges (13) of the second plate 11, whereby each projecting end of each clamping plate is positionable over a respective one of the corner regions 14. Referring now to Figure 3 of the drawings, this shows a top flange plate 11a of a lower I-section beam 15, and a bottom flange plate 10a of an upper I-section beam 16, of which only part of the web 17 is shown. In the illustrated arrangement, the web 17 of upper beam 16 extends perpendicular to the web of lower beam 15. It should further be noted that flange plate 10a rests directly on the upper surface of flange 11a. (Flange plates 10a and 11a are examples of the overlapping plates 10 and 11 shown schematically in Figure 1 ) . As referred to above, a set of four elongate clamping plates is provided, three of which are shown in Figure 3, and each being designated generally by reference 18. Each clamping plate 18 is positioned along a respective one of the connecting edges, as described above in connection with the pairs of edges 12 and 13 shown in Figure 2, and the two clamping plates 18 shown below flange plate 11a extend generally parallel to the axis of the beam 15, whereas the upper clamping plate shown above the flange plate 11a in fact sits flush on the upper surface of flange plate 11a, and extends parallel to the axis of upper beam 16. Although not clearly apparent from each of the two upper clamping plates 18 engages over the upper surface of the connecting edge of top flange plate 10a, in generally similar manner to the way in which nose portions 18a of the two lower clamping plates 18 press against the underside of bottom flange plate 11a. Figure 4 is a plan view of a clamping plate 18, and nose portion 18a is illustrated, which comprises the "toe", and reference 18b defines the "heel", which will engage the surface of the adjacent clamping plate proper. As can be seen in Figure 4, each clamping plate 18 has a pair of axially extending slots 19, and which are of sufficient length to allow adjustment along the length of the slots to suit the particular width of underlying flange plate. Thus, in use, the slots 19 will extend sufficiently far so as to overlie the corner regions 14. A set of four threaded fasteners is provided, designated generally by reference 20, and each being capable of being taken through slot in one of the two upper clamping plate 18 shown in Figure 2, at one corner region 14, and through a slot in the underlying clamping plate at the same corner region. Each fastener 20 will be adjusted along the length of its slot 19 until it is located beyond the connecting edge of the underlying flange plate, and then is tightened in order to clamp the two clamping plates together. Accordingly, a respective threaded fastener 20 ^ can be adjusted.until it is positioned at a respective one of the four corner regions 14, and is then tightened in order to clamp together overlapping flange plates 10a and 11a via the set of four clamping plates as a rigid assembly. In the illustrated arrangement, the beams extend perpendicular to each other, but it will be readily appreciated that the fixing device of the invention can be used readily in order to couple together a skewed junction of overlying beams. In order to provide restraint against any tendency for the fasteners 20 to move longitudinally along the slots 19, after tightening, grooved gripping surfaces 21 are provided — along the edges of the slots 19, and radiused washers 22, 22a (see Figure 3) are fitted on the shanks of the threaded fasteners and make gripping engagement with the surfaces 21 once the required positions of the fasteners have been taken up. Then, upon tightening, a very rigid assembly is obtained, which will resist any tendency for the fasteners to shake loose, or move along the slots 19. This will be of particularly advantage when a fixing device according to the invention is used to join together beams which form part of supporting structure for conveyors or other installations which may generate substantial vibration in use. The washers are shown by references 22 and 22a in Figure 3, and are also shown in more detail in Figures 5a to 5c, which illustrates complementary gripping formations. The lower radiused washer 22a shown in Figure 3 is able to allow the associated clamping plate 18 to rock until nose 18a engages the underside of the flange 11a and the heel 18b engages the other clamping plate, while still maintaining the shank of the fastener vertical, and being restrained from moving along the slot 19 by the grooved surface 21. In this way, the clamping plate can readily be adjusted to suit different plate (flange) thicknesses. Referring now to Figure 6 of the drawings, this shows modification to the fixing device, and this figure generally corresponds with Figure 3, and corresponding parts are given the same reference numerals, and will not be described in detail again. The main modification concerns provision of an additional constructional element on each clamping plate 18, in the form of an extra protrusion or leg to prevent the clamping plates sliding out of engagement with each other when they are being used at the extremity of their adjustment. As shown in Figure 6, the tail portion 18b of each clamping plate 18 has an additional leg or protrusion 18c, and Figure 6b shows the clamping plates 18 at the limit of their adjustment, and in which leg 18c of one of the underlying clamping plates is closely adjacent to leg 18c of the overlying and perpendicularly extending clamping plate. Further, to assist in correct installation of the clamps. Figure 6 shows application of markings 23 which assist in installation, with appropriate marking being determined by experiment for any particular combination of flange plates to be joined together. A central marking 24 is also provided.

Claims: CLAIMS 1. A fixing device for clamping together first and second overlapping plates (10, 11) having respective first and second pairs of opposed connecting edges (12, 13) which intersect at four corner regions (14), said fixing device being operative to clamp the second plate (11) to said connecting edges (12) of the first plate (10) and to clamp the first plate (10) to said connecting edges (13) of the second plate (11), and said fixing device comprising: a set of four elongate clamping plates (18) each positionable along a respective one of said connecting edges (12, 13) of one of said plates (10, 11) and of a length to project axially beyond the opposed connecting edges (12, 13) of the other of said plates (10, 11) whereby each end of each clamping plate (18) is positionable over a respective one of said corner regions (14); slots (19) formed through" each clamping plate (18) and extending generally parallel to the axis thereof so as to overlie said corner region (14); and, a set of four threaded fasteners (20) each being capable of being taken through a slot (19) of one clamping plate (18) at one corner region (14) and through a slot (19) of an underlying clamping plate (18) at the same corner region, each fastener being adjustable along the length of the respective slot until it reaches a required position in the respective corner region and then being tightenable in order to clamp the clamping plates together, whereby a respective threaded fastener is positionable and then tightenable at each corner region in order to clamp together the overlapping plates (10, 11) via the four clamping plates (18). 2. A fixing device according to Claim 1, in which surrounding gripping formations (21) are provided alongside each slot (19), and engageable by clamping elements (22) forming part of the threaded fasteners (20), and which, upon tightening, make gripping engagement and thereby resist any tendency for the fasteners (20) to move thereafter along the length of the respective slot (19). 3. A fixing device according to Claim 2, in which the threaded fasteners (20) include washers (22, 22a) fitting around the threaded shanks of the fasteners and each of which can make gripping engagement with the gripping formations (21) along the slots (19) of the clamping plates (18). 4. A fixing device according to any one of Claims 1 to 3, in which each clamping plate in the set of four clamping plates is of identical design. 5. A fixing device according to any one of Claims 1 to 4, in which at least one of the clamping plates (18) has a projection (18c) extending from a tail portion (18b) of the plate to define an outer limit of relative adjustment of overlying clamping plates. 6. A fixing device according to any one of Claims 1 to 5, in which at least one of the clamping plates (18) is provided with markings (23, 24) o assist assembly of the set of clamping plates on any particular combination of plates (10, 11) to be joined together. 7. A fixing device according to any one of Claims 1 to 6, and used to join together the bottom flange (10a) of an I- beam (16) to the top flange (11a) of an underlying and transversely extending I-beam (15).

Inventors: GILL NEIL FRANK, KNIGHT MICHAEL, GILL, NEIL, FRANK, KNIGHT, MICHAEL
Applicants: GILL NEIL FRANK, KNIGHT MICHAEL, VICTAULIC PLC
Application year: 1993
Main classification: F16B7
IPC codes: E04B1, F16B2