GB2274142A

GB2274142A - Joint for space frames

Info

Publication number: GB2274142A
Application number: GB9300226A
Authority: GB
Inventors: Hamizar Hamid
Original assignee: P T RANGKA RUANG
Current assignee: P T RANGKA RUANG
Priority date: 1993-01-07
Filing date: 1993-01-07
Publication date: 1994-07-13
Also published as: GB9300226D0

Abstract

A framework tube (2) is connected to a connection node (1) by means of a bolt (6) which is retained in the tube (2) by a plate (7) and which is screwed into the node (1) by rotation of a hexagonal sleeve (8) keyed to the bolt (6) by a groove-and-ball arrangement (9). The disc (4) is welded to the tube (2) and galvanised, and then the bolt (6) is inserted into the tube (2). <IMAGE>

Description

JOINT CONNECTION FOR SPACE FRAME STRUCTURE Field of the Invention This invention relates to the joint between a hollow profile member, nut, bolt, inner plate, end plate and ball joint which comprises a space frame structure.

Background of the Invention A known joint connection is disclosed in German Patent no. 1.815.849. In this document there exists a connection through a hole in the wall of the hollow profile member to the bolt; the bolt head is equipped with a duct so that the bolt can be turned through the hole in the wall of the hollow profile member. The drawback of this system is that the hexagonal nut and the bolt therein need to be welded to the pipe first.

Thereafter the complete element, including the weld, is galvanised in such a way that the bolt is not galvanised so that it is still free to turn. This process is costly and complicated. Another disadvantage is that the hole in the wall of the member becomes a weak point in transferring structural loads.

Furthermore, percautions need to be taken to seal the hole to avoid incoming moisture which causes corrosion.

Disclosed in European Patent no. 0 083 356, is a similar connection in which a curved duct exit connects a hole in the member to the end plate.

After the end plate is welded to the member and galvanised, the bolt, which is not galvanised, is inserted through the hole in the wall of the member into the hole in the end plate. In this system there still exists the structural weakness due to the hole in the wall of the member. Also there is a problem in uniformly galvanising the member and disposal of excess galvanising fluid.

To solve the above problems a joint connection is disclosed by the applicant which is produced in such a way that the inner plate will bear the tension forces and the hexagonal nut will transfer the compression forces to the end plate.

SummarY of the Invention Accordingly there is disclosed a framework of hollow profiles comprising bar elements which converge at separate joints. The joints have several connectors for identically shaped bar elements. The connectors form three-dimensional and/or two-dimensional angles and have threaded holes in their open ends. End plates (discs), each with a central perforation, are fixed to the end portion of the hollow sections (bar elements).

There are also provided inner plates and bolts, the bolts of which are screwed into the threaded holes in the connection side. The inner plate and bolt are inserted in the right sequence tied by a string, into the central perforation with the head of the bolt arranged within the hollow section. A hexagonal nut separates the connector from the disc, and by turning the nut this causes the bolt to move into the connector.

The hollow sections, discs, hexagonal nuts, inner plates and the connectors have the appropriate identical external profiles for producing a framework free from holes in the hollow profile elements, except in the discs. The disc is welded to the end edge of the hollow section while the end plate prevents the bolt from moving outside the hollow section by tension forces induced on the latter. The shoulder of the hexagonal nut prevents the connector from moving to the hollow section induced by compression forces.

Various shapes can be chosen for the nut that holds and turns the bolt, for example, square, hexagon shapes etc.

DescriPtion of the preferred embodiment Reference will now be made in detail to the present preferred embodiment of the invention, an example of which is illustrated in the accompanying drawing which shows a cross-sectional view of the invention.

A connection node for a framework comprising bars joined to one part (1). That part of the connection has a plurality of supports with threaded holes (3) for hollow bars (2) having complimentary shapes. Each bar is provided at its end, an end plate (4) having an opening wherein a bolt (6) and an inner plate (7) are inserted. The bolt, the head of which penetrates the end plate (4), is held and guided by a hexagonal nut (8) and then screwed into the threaded hole (3) of the ball joint (1).

The inner plate (7) and the hexagonal nut (8) are secured by the end plate (disc) to form a guidance for the bolt (6). To prevent the bolt from slipping out of the end plate (4), the bolt head is blocked by the inner plate (7). The advantage of this connection is that no additional hole, which weakens the bar, has to be made and that after hot-dip-galvanising the bolt (6) can be inserted into the bar and in conjunction with the inner plate (7) and hexagonal nut (8) can transfer the forces induced into the bar of the framework.

The bolt (6) can be fastenend to the ball joint (1) through the assistance of the hexagonal nut (8) and one or more ball bearings (9). The ball bearing is placed in a template made on the bolt (6) while on the inner side of the hexagonal nut (8), a groove is provided for passage of the ball bearing (9).

Although the invention has been described and illustrated with reference to a specific embodiment, it will be understood by those skilled in the art that various modifications and variations may be made without departing from the spirit and scope of the present invention.

Claims

1. A space frame structure comprising a hollow section (2) joined to a connector (1) by means comprising a disc (4) with a perforation, fixed to an end portion of the hollow section (2), an inner plate (7) within said hollow section (2), a bolt (6) wherein the head of said bolt (6) is arranged within the interior of the hollow section (2) through the perforation of said disc (4), a threaded hole (3) provided in said connector (1) at its open end, a nut (8) complementary to said bolt (6) and when said nut (8) is turned it moves the bolt (6) into said threaded hole (3) of the connector (1).

2. A space frame structure as claimed in claim 1 characterised in that no additional hole exists in the hollow section (2).

3. A space frame structure as claimed in claim 1 characterised in that the bolt (6) is fastened to the connector (1) through the assistance of the nut (8) and one or more ball bearings (9) placed in a template made on said bolt (6) while on the inner side of said nut a groove is provided as a passage for said ball bearings (9).

4. A space frame structure as claimed in claim 1 characterised in that the disc (4) is welded to the hollow section (2) and then galvanised.

5. A space frame structure as claimed in claim 1 wherein tension forces that exist are transferred to said disc (4) by the inner plate (7).

6. A space frame structure as claimed in claim 1 wherein compression forces that exist are transferred to said disc (4) by the shoulder of the nut (8).

7. A space frame structure as claimed in claim 4 wherein after galvanising the bolt (6) is inserted through the hole in the disc (4) in conjunction with said inner plate (7).

8. A space frame structure as claimed in claim 1 wherein the nut (8) is hexagonal in shape.