IE893916L - Device for connecting the members of collapsible framework¹structures capable of being dismantled - Google Patents

Abstract

In a device for releasably connecting the girders of framework structures, claws (3) are mounted at the free end of each girder, the claws engaging in recesses (9) of joint plates (4, 5) connectible by means of a screw (6). The joint plates (4, 5) are formed as circular discs one of which has a central through opening for a screw and another of which has a central threaded bore for the screw (6), the discs having the recesses (9) in their faces directed towards one another, concentric with the central opening or bore. The claws (3) of the girder are formed by projections in the form of circular sectors having a claw (3) at each side, curved to correspond to the configuration of the grooves, the claws being insertable between the joint plates, (4, 5), and being engageable in the recesses (9) of the plates. <IMAGE> [DE3841281A1]

Description

62329 - i - DEVICE FOR CONNECTING THE MEMBERS OF FRAMEWORK STRUCTURES CAPABLE OF BEING DISMANTLED The invention concerns a device for connecting structural members in a dismantleable framework in the form of a girder having upper and lower girder parts, the device comprising a joint assembly which comprises joint parts connected in use to respective ends of girder chord parts, and a pair of joint plates between which the joint parts are bolted, projections or claws on the joint parts engaging in recessess in the joint plates.

A device of this kind is known for example from German Patent Specification No 3222811.

In the known device, a claw is provided on both the upper chord and on the lower chord, in each case secured by means of welding, the claws being arranged to extend in opposite directions from one another. The claws are connected to the welded-on plates by means of narrow flanges extending vertically in the direction of assembly. These plates are mounted by welding on the corresponding chords of the lattice girders, the chords being formed as hollow sections. For assembling the joint plates, a joint member is provided, at a lower end of which a joint plate is fixedly welded on, while at its upper end, which is connectible to the upper chord, a releasably assembled joint plate is retained by means of a centrally disposed screw. In this known construction, the joint plates are provided, in their side regions which project above the joint member, with recesses open at the edges, in the form of slots and extending in the direction of the members to be connected, the claws or their flanges being engageable in the recesses.

The provision of slot-form recesses has proved disadvantageous 62329 in this font of embodiment, since they become widened out in the presence of tensile forces affecting the joint and in the extreme case they may even tear apart, so that a sufficient degree of safety is only to be achieved by substantial additional expense in construction, especially in the case of multi-storey construction.

Proceeding from this state of the art, it is an object of the invention to provide a device of the foregoing kind, which is able to withstand any loads applied in a problem-free manner by the use of joint parts which are very simple to. manufacture, but without any consequent expectation of damage to the joint plates.

According to the present invention there is provided a device for connecting structural members in a dismantleable framework in the form of a girder having upper and lower girder chord parts, the device comprising a joint assembly which comprises joint parts connected in use to respective ends of girder chord parts, and a pair of joint plates in the form of a pair of opposed circular discs, one disc of the pair having a central opening for a bolt, and the other disc having a central threaded bore, whereby the discs are, in use, bolted together with the joint parts therebetween, each joint part comprising a circular segmental flange plate, in use received between the discs, and a connecting portion at which connection is made to the girder cord part and which in use is external of the discs and which is curved to correspond to the external shape of the discs, the connecting portion and the discs terminating flush in the axial direction of the bore or opening, the circular segmental flange plate having arcuate depending and upstanding projections which extend into corresponding annular groove-like recesses formed in the opposed faces of the discs and centered about the central bore or opening therein, the depth of the groove-like recesses being slightly greater than the free length of the depending or upstanding projections.

A divergence from the state of the art exists at each chord end. Thus both on the upper chord and also on the lower chord 5 of a lattice girder, a projection is mounted directed upwardly in the assembly direction and another projection is directed downwardly in the assembly direction. These projections are connected to welded-on plates by means of flanges which are horizontal in the assembled position, the connecting portions 10 comprising plates welded on at the ends of the hollow sections which form the upper chord and the lower chord of the lattice girder. A further difference from the state of the art is that a pair of joint plates are provided for each pair of projections of a lower chord and of an upper chord, so that in 15 the assembled position, the projections are covered on the upper side and on the lower side in each case by a joint plate, and further, the joint plates have groove-form recesses in their faces directed towards one another, concentric with the central opening, in which the projections may be engaged. 20 The screw or bolt which in each case connects the joint plates of a joint and therefore also of the lower chord or of the upper chord has a length such that in preassembly of the joint plates relative to one another, the plates may be spaced at a distance from one another such that the corresponding chord 25 with its projections may be inserted between the joint plates and engaged in the recess of the respective joint plate.

As soon as all upper chords and lower chords extending from the joint are correctly positioned at the joint, the bolt may 30 be tightened and optionally tensioned, so that a frictional and positive connection of the upper chords and the lower chords may be achieved by the joint plates. The manufacture of the parts of the joint assembly, of the welded-on components and the projections as well as the joint plates, is 35 very easy to effect, since these connecting members may be made as straightforward turned components. For the manufacture of the joint parts having the projections, these may be first of all turned from a circular disc, optionally shaped at its edges, and then divided into a suitable number 5 of part-circular segmental individual components, preferably into four identical segment parts.

By means of the construction according to the invention, the formation of the open-edged slots which were hitherto 10 necessary for engagement of the projections or their flanges is avoided, so that substantially higher loads may be taken up, and in addition, tearing apart of the slots, which was a hazard with the state of the art slots, is no longer possible.

It is also especially advantageous in the construction according to the invention that the components are flush so that following completion of assembly, an optically unitary aesthetic impression is achieved at the joints, so that an aesthetically satisfying solution is also found. The 20 constructions according to the invention also facilitates the erection of multi-storey structures using this system, in which the framework formed by the lattice girders is suitable for mounting floor components, wall members and ceiling parts.

A preferred construction is also seen in forming and disposing the groove-like recesses of a pair of discs, as well as the discs themselves, to match each other.

More theoretically, it is also possible for the groove-like 30 recesses to have a different spacing from the central axis of the respective joint plate. For reasons of uniform loading and transmission of forces, it is however preferred that these recesses should be arranged to match, the inevitable outcome being obviously that the projections also must in each case 35 have the same spacings from the ends of the upper chord and of the lower chord.

Furthermore it is preferably provided that each circular segmental flange plate covers at least approximately one 5 quadrant of the associated disc.

A preferred embodiment is seen in that the discs and curved connecting portion are formed to be, in use, axially flush with the girder chord part.

In this it can be further advantageous if the projections are not disposed at the free end of the flange carrying them, but that the flange plate extending from the connecting portion which is secured to the chord projects beyond the projections 15 in the longitudinal direction of the flange plate, which extends horizontally to the assembly direction, so that the groove-like recesses for reception of the projections may be disposed at a substantial spacing from the central opening.of the disc-form joint plates.

It is further provided that the projections have a free length corresponding approximately to the thickness of the flange plate carrying them.

Preferably it is further provided that the discs are approximately three times as thick as the projections.

In order to achieve a good fit, it is further provided that the grooves and the projections are shaped frusto-conically in 30 section.

Furthermore, it is preferred that in an assembled girder the heads of the bolts are in each case arranged on the inner side of the girder with respect to the upper and lower chord of a 35 girder, and the discs provided with a threaded bore are arranged on the outer side.

In a further embodiment it is proposed that the inwardly-disposed discs of a girder be connected to one 5 another by means of a joint member or pillar.

In this manner it is possible to be able to also provide joint members or pillars at structurally determined positions.

Furthermore, it is possible for the outwardly disposed discs to be connected to a pillar or an upright.

In this manner it is possible for the lattice girders to be supported on their upper side by the floor located above them 15 and to be supported on their lower side either on the floor located below them or the ground floor.

Embodiments of the invention are shown in the drawings and are now described in detail in the following text.

Figure 1 shows a joint assembly in a chord of a lattice girder in side view, partially in section; Figure 2 shows the sam joint assembly seen from below; Figures 3 to 8 show individual connecting members of the joint in individual views; Figure 9 shows the connection of lattice girders having joint 30 members and struts, in side view, partially broken away; Figure 10 shows a joint in a view corresponding to that of Figure 1; Figures 11 and 12 are representations of the principles underlying framework assemblies incorporating the connecting device according to the invention; and Figure 13 shows a variant -in the representation according to 5 Figure 1.

In the drawings, the device for connecting the members of framework structures capable of being dismantled is shown, in which at the free end of an upper chord 1 and of a lower chord 10 2, joint parts having double projections 3 are mounted, which engage in corresponding recesses of joint plates 4 and 5. In each case, the two joint plates 4 and 5 of a joint are connectible by means of a bolt 6 passing centrally through them. According to the invention, the joint plates 4 and 5 15 are formed as circular discs, as can be seen in particular from Figures 3 to 6. One of the discs, 4, has a central through opening 7 for a bolt, while the other disc 5 has a similar central threaded bore 8. Concentric with the central opening 7 or 8, channel-shaped recesses 9 are provided in the 20 faces of the discs 4 and 5 which are directed towards one-another. The channels or grooves are formed by closed annularly-configured recesses. The members carrying the projections 3 are formed in circular segmental or sectoral manner by means of wleded-on parts 10, as can be seen in 25 particular from Figure 7. These members are for welding onto the girders.

At each end of an upper chord 1 or of a lower chord 2, a member of this kind is welded on. The projections 3 extend 30 therefore during assembly vertically from a projecting web or flange plate 11 of the welded-on part, this web or flange plate extending in a horizontal direction in the assembled position. The sectoral projections formed by the flange plates 11 are provided on each side with projections 3, 35 projecting in the direction of the groove-like recesses 9 and curved to correspond to the shape of these grooves or channels. These projections 3 are in each case insertable, in the assembly position, between the joint plates 4 and 5 and engageable in their groove-like or channel-shaped recesses 9. During pre-assembly, the bolt 6 is only loosely screwed into the threaded hole 8 of the disc 5, so that the discs 4 and 5 have a spacing between their facing surfaces such that the double projections 3 may be inserted into the intermediate space thus defined and then introduced into the recess 9 which is lowermost in the assembled position. During assembly, the attachment of further lattice girders to an already finished erected lattice girder takes place in such a manner that the discs 4 and 5 are engaged against the corresponding end portion (double projection 3) of the erected lattice girder by means of the loosely screwed-in screw 6, so that the disc 4 or 5 which is uppermost in the assembly direction is located with its recess over the projection 3 which extends upwards with respect to the assembly direction. The further lattice girders may then be introduced into the space defined between the discs 4 and 5 of a joint, following which the lower projections 3 of these lattice girders are located in the recess 9 which is then lowermost. After the insertion of all connecting members at this joint, the screw 6 is tightened up, following which the connection at this joint is complete. The bolts are preferably formed as bolts having internal polygonal openings in their heads by which they may be tightened using a suitable key or spanner (high tensile screws).

Because of the annular configuration of the recesses 9 and the corresponding circular sectoral shape of the projections 3, it is possible to assemble lattice girders at different angles to one another at a joint. In particular embodiment, the dimensions are so chosen that in the case of four lattice girders coming together at a single joint, only a right-angle disposition of the lattice girders with respect to one another is possible. Insofar however as only three such lattice girders are to be connected together at a joint, a relative angular disposition devii disposition is possible. angular disposition deviating from the symmetrical 120° The groove-like recesses 9 of a pair of discs 4,5 are also • formed and designed to be the same as one another, as are the discs themselves. Furthermore, each circular segmental projecting flange or web portion 11 extends over at least a quarter circle of the associated disc 4 or 5. The connecting 10 part 10 of each segmental projection is curved to correspond to the exterior shape of the disc 4 or 5 in the region abutting against the chord 1 or 2 of the girder, so that the discs 4,5 are flush with the one or the other edge periphery of the curvature in their mounted positions, as is shown for 15 example in Figure 1, and the components forming the chords 1 and 2 are also aligned flush with the curvature. In the embodiment, the projections 3 have a free length corresponding approximately to the thickness of the projection 11 which carries them. The discs 4,5 are approximately three times as 20 thick as the projecting flange 11. As can be seen for example from Figures 3, 6 and 8, the grooves 9 and the projections 3 have conical shapes which match one another, the grooves 9 having a depth slightly greater than the free length of the claws 3, so that in the desired assembled disposition, as is 25 shown for example in Figure l, the end surfaces of the projections 3 in the vertical direction have a spacing from the base of the recess 9. In this way, double fit (in which the end surfaces of the projections 3 engage the bottom of the grooves 9 simultaneously with the engagement by the plates 4,5 30 of the flange 11) is avoided.

For cantilevered or self-supportingly located lattice girders, the assembly is preferably so arranged that the heads of the bolts 6, which project on the external side of the thread-free 35 disc 4, are in each case disposed on the inner side of the girder with respect to the upper chord 1 or the lower chord 2 of a girder, while the disc 5 provided with the threaded hole is disposed on the other side. This is shown for example in Figure 10. In this way, an aesthetically especially successful impression is achieved, since the heads of the bolts as a disturbing element are practically invisible from the exterior. In addition, the bolt heads do not then form projections interfering with the installation of ceiling or floor elements. In the embodiment according to Figure 9, the inwardly-disposed discs 5 of a joint are connected to one another by means of a joint member or column 12. The joint member is formed as a hollow section. For securing the joint member, a connecting member 13 is in each case welded onto the disc 5. These connecting members ar aligned coaxially with one another. The joint member 12 is mounted by means of corresponding securing screws 14, preferably screws having internal polygonal openings in their heads. Member. 12 has centrally apertured end plates 15. In order for the screws 14 to be accessible for a suitable tool, the joint member has openings 16, into which the flexible shaft of a screwdriver may be introduced in known manner, so that the screws 14 may be tightened by motor means. Similarly, in Figure 9 of the drawings, the outwardly located discs 4 are shown to be connected by a pillar 18 or an upright 17. For adjustment and to ensure correct positioning, a sleeve-form socket 19 is welded onto the disc 4 centrally, over which a corresponding end plate 2 0 of the pillar or of the upright engages. In this manner, a sufficient level of accuracy in positioning is achieved. Obviously it is also possible to connect up the pillar or the upright by means of a welded connection or a screw connection. In order to achieve sufficient clearance for movement relative to the inclined struts 21 of the lattice extending from the lower chord 2 or the upper chord 1 and to achieve an at least approximately concentric entry of the inclined struts 21 into the joint, the inclined struts 21 are received in the connection region of the discs 5 and 4, the recess 22, which corresponds to the required spacing of the discs 4 and 5 from one another, having a height such that the introduction of the projections 3 between the pre-assembled discs 4 and 5 is possible.

In Figures 11 and 12 of the drawings, two possible variants of embodiments of girder structures are shown. In the variant of Figure 11, an upright or a pillar 17 or 18, as well as a joint member or column 12, is provided at each joint of the lattice girders. In this manner, for example, the construction of multi-storey structures is possible. In the variant according to Figure 12, the arrangement is so devised that only uprights 17 are provided, with as a result the fact that the inclined struts of the lattice girder converge in each case at the upper end point of the upright 17. In this arrangement additional joint members 12 may be avoided. This means on the one hand a substantial cost saving, and on the other hand, a slopingly extending configuration of the framework is in this manner possible on the outer skin of the structure, as is to be seen at the left-hand side of Figure 12.

The embodiments in no way represent a limitation.

In deviation from the embodiments shown, the head of the bolt 6 may obviously also be arranged to be sunk in an appropriately stepped receiving bore in the disc 4, a screw having an internal polygonal head opening then preferably being used.

All components of the device preferably consist of steel.

For aesthetic reasons, it may also be advantageous for the threaded bore 8 to be formed as a blind hole, so that the outwardly directed surface of the disc 5 in the assembled position may be formed to be flat and smooth and free from openings. It is also possible to connect girders rigidly to 35 one another using the connecting components formed according to the invention, in which for example at the end of two girders to be connected to one another, connecting parts 10 forming a circular sector of 180° are in each case welded-on. In the assembly of girders of this kind with corresponding discs 4,5 a continuous connection is achieved which is rigid in the axial and the radial directions of the connecting member. It is also possible to fit girders with welded-on components 10 having web or flange portions 11 extending over 90° of a circular sector. The free space between the two 90° sectors may then be filled by means of appropriate filler portions (also 90° sectors).

In particular in the case of tensile loading occurring, it is advantageous for the transition between the curved welded-on part 10 and the segmental flange part 11 to have a radius of for example 10mm, the discs being bevelled on their inwardly facing edges. This bevelling should extend at a maximum over approximately one-third of the height of the disc 4 or 5 from its inner abutment edge against the flange part 11. By bevelling the discs 4 and 5, a further aid to assembly is also provided. Furthermore, it is possible for the fitting of the welded-on part 10, projections 3 and recesses 9 of the discs 4 and 5 to be effected so that in the event of tensile forces occurring, the flanks of the projections 3 that are loaded in the tension direction abut in a load-carrying manner on the sides of the recesses 9, while in the case of compressive forces occurring, the surfaces of the welded-on parts 10 abut against the radially outwardly-disposed surfaces of the discs 4,5. The side edges of the projectins 3 which are forwardly located with respect to the direction of compressive loading may have therefore a certain spacing or clearance from the corresponding associated flanks of the recesses 9 or the discs 4,5.

This variant is shown in Figure 13 of the drawings.

Claims (14)

1. A device for connecting structural members in a dismantleable framework in the form of a girder having upper and lower girder chord parts, the device comprising a joint assembly which comprises joint parts connected in use to respective ends of girder chord parts, and a pair of joint plates in the form of a pair of opposed circular discs, one disc of the pair having a central opening for a bolt, and the other disc having a central threaded bore, whereby the discs are, in use, bolted together with the joint parts therebetween, each joint part comprising a circular segmental flange plate, in use received between the discs, and a connecting portion at which connection is made to the girder cord part and which in use is external of the discs and which is curved to correspond to the external shape of the discs, the connecting portion and the discs terminating flush in the axial direction of the bore or opening, the circular segmental flange plate having arcuate depending and upstanding projections which extend into corresponding annular groove-like recesses formed in the opposed faces of the discs and centered about the central bore or opening therein, the depth of the groove-like recesses being slightly greater than the free length of the depending or upstanding projections.

2. A device according to claim l, wherein the groove-like recesses of a pair of discs as well as the discs themselves are formed and disposed to match one another.

3. A device according to claim 1 or 2, wherein each circular segmental flange is at least a quarter circle.

4. A device according to any one of claims 1 to 3, wherein, in use, the discs and the curved connecting portion are formed to be axially flush with a connected girder chord part.

5.- A device according to any one of claims 1 to 4, wherein the depending or upstanding projections have a free length corresponding approximately to the thickness of the flange plate carrying them.

6. A device according to any one of claims 1 to 5, wherein the discs are approximately three times the thickness of the flange plates.

7. A device according to any one of claims 1 to 6, wherein the grooves and the projections are frustoconical in section.

8. A device according to any one of claims 1 to 7, wherein the thickness of the discs, length of the bolt, depth of the recesses and free length of the projections are arranged whereby the discs can be loosely connected by the bolt whilst still allowing insertion therebetween or removal of the joint parts.

9. A device according to any one of claims 1 to 8 when employed in an assembled girder wherein the head of the bolt is disposed inwardly of the girder with respect to the upper and lower chords of the girder and the disc provided with the threaded bore is disposed outwardly.

10. A device according to any one of claims 1 to 9 when employed in an assembled girder wherein discs disposed inwardly of the girder are connected to one another by a joint member.

11. A device according to any one of claims 1 to 10, when employed in an assembled girder wherein discs disposed outwardly of the girder are each connected to a pillar or an upright. - 15 -

12. A connecting device according to claim 1 substantially as described herein with reference to and as shown in Figures 1 to 8, Figure 9, Figure 10 or Figure 13 of the accompanying drawings. 5

13. A framework assembly comprising a connecting device according to any of claims 1 to 12.

14. A framework assembly according to claim 13 substantially as described herein with reference to Figure 11 or 12, in combination with 10 Figures 1 to 8, 9, 10 or 13 of the accompanying drawings. TOMKINS & CO. 15 20 25 30 35