STRUCTURAL CONNECTION SYSTEM
This invention relates to a structural connection system and in particular to a system which is adapted to connect structural members which are not directly in alignment with each other.
Normally, to make a good joint between structural members, it is desirable that faces of the members are in abutment and the connection can be made by a bolt or the like passing through apertures in the members and having a nut holding the members together.
Associated with the nut and the adjacent aperture there may be some form of spring or other washer which prevents inadvertent loosening of the nut and whilst such an arrangement is not mentioned in this specification the connection would be done in a conventional manner.
There are many applications where straight members would not be in abutment when they were located and for an exemplification we will refer to power transmission towers.
These towers are established on a relatively large base and tend to taper over their height so the construction components tend to come into contact with each other at an angle.
Normally, in order to produce such towers, many of the members have to be deformed at one or both ends so that they can be brought into abutment with the member(s) to which they are being connected.
This necessitates the members being fabricated off site and, generally, the members are basically unique, or there are a small number of members having the same characteristic. This means, of course, that during fabrication the fabricators have to ensure that the correct members are located in the correct position.
It is an object of the present invention to provide a structural connection system in which the members to be connected are not deformed but the connecting arrangements themselves take into account any misalignment between the members.
The invention in its broadest sense comprises a system for connecting at least two members which are not aligned with each other, each of which has an aperture therethrough and a bolt or the like adapted to pass through the apertures and means to ensure that this is retained therein characterised in that on each side of one of the members there is a member having a formed surface directed towards a member having a complementary surface, the cooperating surfaces enabling the elements to be positively connected.
Preferably, the formed surface is a spherical or truncated spherical surface or a cylindrical surface..
The invention also shows the face of the members having formed surfaces away from the deformed surface being flat and wither normal to or at an angle to the axis of the aperture through the member. If at an angle, then I may use a tapered washer to ensure that good contact is made.
In order that the invention may be more readily understood, reference will be made to accompanying drawings which relate to its use in an electrical transmission tower.
In these drawings:
Fig 1 shows portion of a conventional tower;
Fig 2 shows similar portion of a tower incorporating the invention;
Fig 3 shows an exploded perspective of the components of a joint incorporating the invention;
Fig 4 shows an exploded view of the joint shown at 4 on Fig 2;
Fig 5 shows a sectional view of the joint of Fig 4;
Fig 6 shows an exploded view of the joint shown at 6 on Fig 2;
Fig 7 shows a sectional view of the joint of Fig 6;
Fig 8 shows an exploded view of the joint shown at 8 on Fig 2;
Fig 9 shows a sectional view of the joint of Fig 8;
Fig 10 shows an exploded view of the joint shown at 10 on Fig 2;
Fig 11 shows a sectional view of the joint of Fig 10;
Referring to Fig 1 , it will be seen that the transmission tower is constructed of a number of elongate members which may generally be of steel angle, although other profiles may be used.
As the tower generally tapers from a wide base to a narrower upper end the members are generally not connected to each other square and to make the connection, the members must normally be deformed at one or both ends. For example, the member shown as 10 has one end 11 bent inwardly to abut a face of member 13 and the other end 12 bent to abut a flange of plate 14.
Because of the deformation of the members, it is necessary that in most cases the members are unique and this necessitates that the members be pre-fabricated in a workshop and need to be identified so that they are located at the required position.
This is both expensive and inconvenient.
The present invention provides a joint which enables undeformed members to be interconnected but which, at the same time, ensures that the joint is effective.
Fig 3 shows an exploded view of a joint of the invention and this is adapted to interconnect two members 20,21. The members 20,21 have apertures 22,23 respectively, the apertures being at the required position of connection and I provide a bolt 24 and a corresponding nut 25 to effect the securing. The apertures 22,23 may be of a diameter somewhat larger than that of the bolt 24 as will be explained hereafter.
The connector has four components. Two of these components 26 have one flat face 28 and one part spherical face 29. The other two components 27 have one flat face 30 and one part spherical recess 31. Each component has an aperture therethough which apertures are effectively axial to the part spherical surfaces.
Each spherical face and its associated spherical recess are of substantially the same radius of curvature.
Whilst I refer to the face and the recess as being spherical it is not essential that they are completely spherical they may, for example be, truncated but have a spherical or cylindrical portion.
The arrangement, as can be seen, is such that abutting the head of the bolt is the flat face 30 of member 27. Also on the bolt adjacent the member 27 there is a member 26 and the
spherical face of the member 26 is directed towards the spherical recess of the member
27.
The bolt 24 is then passed through the aperture 23 of members 21 and the other two members 26,27 are passed over the bolt with their flat surfaces 28,30 being outwardly directed. The bolt 24 then passes through the aperture 22 of the member 20 and the nut 25 is connected thereto.
If the two members 20,21 are not aligned as the nut 25 is tightened, the spherical faces of the members 26,27 automatically adopt positions one relative to the other so that a good connection is made.
Certain exemplifications of the invention are shown in Figs 4 and 5; Figs 6 and 7; Figs 8 and 9; and Figs 10 and 11. These relate to the connections shown as 4, 6, 8 and 10 of Fig 2, that is types of connections which are used in an electricity transmission tower.
Referring first to Figs 4 and 5, there are three members which are to be connected with member 31 being equivalent to member 21 of Fig 3 and the webs 32 and 33 being webs of two members which are coplanar so that they are in contact. Fig 5 shows well how the two members 26 enable the members to be connected with the coplanar members being at an angle to member 31. At the same time, as the arrangement self-aligns, the connection is positive.
Referring to Figs 6 and 7, we have two members 40,41 to be connected with the members being at a substantial angle to each other. It could be difficult using only the connection of the invention as previously described to cope with this degree of variation as the members 26 would have to be of a large diameter to permit the bore to be large enough to accept the angle. In this case the member 27" has its outer face flat, to make good contact with member 41 but the face is not normal to the axis of the member 27" but at
an angle thereto. In this case to make good contact with the nut 25, 1 use a tapered washer 42 on the side of the member 41 away from the member 27".
Referring to Figs 8 and 9 the member 27"' has its outer face at an angle to normal somewhat similarly to the arrangement of the previous embodiment but in this case the divergence from normal is less than the previous embodiment. Again we have a tapered washer 42' which corresponds to the angle of the member 27"'. In this case also, the member 51 is two members which are parallel to each other.
It may be that there can be a small number of angles of the face of the member 27 and the corresponding washers 42 as a substantial part of any mis-alignment can be compensated for by the cooperating parts of the members 26,27.
Referring to Figs 10 and 11, the members 60 and 61 of this embodiment are not only at an angle to each other but are spaced to permit clearance between the brace and the upright member. In this embodiment, this is overcome by having a spacer 62 and a pair of complementary tapered washers 63, 64 to assist in the alignment of the members.
The main feature of these embodiments and other embodiments of the invention is that the members to be connected are planar. Of course, the invention could be applied to an arrangement where the members to be connected are deformed to a required angle if the deformation is greater than would be prudent for the particular member or if the off site deformation is inaccurate.
In this specification I have described the convex members 26 as those which are in contact with one of the members 20, 21 to be connected, and this effectively forms a ball and socket joint with the corresponding concave members 27.
This can readily be seen from Figures 5, 7 et al. The arrangement can be reversed so that the convex members are the ones which are spaced from the member to be connected and are received by the concave members abutting one of the members to be connected.