AU647789B2

AU647789B2 - Nodal connection for space frame

Info

Publication number: AU647789B2
Application number: AU77308/91A
Authority: AU
Inventors: Phillip Graham Calow
Original assignee: NOVAPLAS Pty Ltd
Current assignee: NOVAPLAS Pty Ltd
Priority date: 1990-05-21
Filing date: 1990-05-21
Publication date: 1994-03-31
Anticipated expiration: 2011-05-21
Also published as: AU7730891A

Description

l i -iii-- 647789

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION For a Standard Patent

ORIGINAL

TO BE COMPLETED BY APPLICANT Name of Applicant: Actual Inventor(s): Address for Service: NOVAPLAS PTY LTD PHILIP GRAHAM CALOW WRAY ASSOCIATES, Primary Industry House, 239 Terrace, Perth, Western Australia, 6000.

Adelaide Attorney code: WR Invention Title: "Nodal Connection for Space Frame" Details of Associated Provisional Application: No: PK0234 The following statement is a full description of this invention, including the best method of performing it known to us:-

I

2 THIS INVENTION relates to space frames and in particular to a nodal connection for intersecting frame members of a space frame.

Space frames provide a framework which generally covers a large space or area, and thus usually utilises a large number of parts and large lengths of material. Space frames can also be required to carry substantial loads, and at the very least must be capable of supporting its own weight which in most cases is not insubstantial. These requirements present some difficulties in the manufacture, construction, and final presentation of traditional space frames; namely, large, bulky, and visually unappealing nodal connections which require a large number of bolts or the like in order to provide the strength required. These bulky connections are labor intensive in their manufacture and construction, and are cost intensive due to the number of parts required, both to form the connection and usually to cover the connection from view. Also, the connections are generally structurally weaker due to the large number of apertures required for connection.

The object of the present invention is to provide a nodal connection which overcomes, or at least partly alleviates, the above difficulties.

The present invention provides a nodal connection for intersecting frame members of a space frame, the nodal connection comprising a flattened section on each frame member, a single connecting aperture in each flattened section, the flattened sections being disposed in face-toface relationship one adjacent another with the connecting apertures in alignment, and connecting means including a single connecting shank received in the aligned apertures for securing the flattened sections together, the S connecting means further including support means engaging 9 w against an

F,

-3outermost flattened section for supporting that outermost flattened section against bending under load.

In a preferred form, the support means bears against a major portion of the flattened section of the outermost frame member, and is substantially rectangular when viewed along a line corresponding to the longitudinal axis of the shank. Preferably, the support means is square when viewed along that line.

The support means preferably has a thickness which exceeds the thickness of the flattened section of the outermost frame member. In one embodiment of the invention, the support means is in the form of a square clamping plate captively retained on the connecting shank. The shank may be defined by a connecting bolt received in the connecting apertures and onto which the clamping plate may be mounted.

Preferably, the frame members are of tubular construction, the nodal ends of the frame members being crushed to define the flattened sections. However, the frame members may be similarly crushed to form a flattened section intermediate the nodal ends.

At least one frame member may be inclined to the longitudinal axis of the shank, the support means engaging against the flattened section of the outermost frame member on the side of the nodal connection to which the inclined frame member extends. However, in a preferred form there are a plurality of inclined frame members extending to a common side of the nodal connection.

In another form, the invention resides in a space frame comprising frame members interconnected by a nodal connection as described above.

-4- The invention will be better understood by reference to the following description of one specific embodiment as shown in the accompanying drawings, in which:- Figure 1 is a schematic view of a space frame incorporating frame members interconnected with nodal connections according to the embodiment; Figure 2 is a detailed view of the assembled nodal connection of the embodiment; and Figure 3 is a view similar to Figure 2 with the exception that the nodal connection is shown in an exploded condition.

The embodiment shown in the drawings is directed to a nodal connection which is employed in a space frame which is shown schematically in 7igure 1 and which comprises a plurality of horizontal frame members 11 defining chords and a plurality of inclined frame members 13 defining webs.

The chords 11 define two frame structures being an upper frame structure 15 and a lower frame structure 17. The chords of the upper and lower frame structures 15 and 17 are arranged in a series of rectangular formations (as best shown in Figure 1) and are interconnected by the chords 13 at nodes 19. Thus, at each inner node 19 there are four coplanar chords 11 which are disposed at 90" to each other and four webs 13 each disposed at 45* in plan to the plane carrying the chords 11. Of course, the nodes at the edge of the frame have only three such members, while the nodes *at the corners have only two such members.

A nodal connection 21 (illustrated in Figures 2 and 3) provides a means of connecting the intersecting frame members 11 and 13 at each node 19.

Each nodal connection 21 comprises a flattened section 23 at the nodal end of each frame member. The flattened sections 23 are here shown as being only at the nodal ends.

However, the flattened sections 23 may be intermediate the nodal ends of either the chords or the webs. This would provide more continuity in the frame, and in some instances will provide greater strength.

The frame members illustrated are of tubular construction and the flattened section is formed by crushing the end of the tubular frame member. The flattened section 23 of each horizontal frame member 11 extends axially from the frame member while the flattened section of each inclined frame member 13 is inclined to the longitudinal axis of the frame member such that the flattened section can assume a horizontal condition when the frame member is assembled.

The inclination between th3 flattened section 23 and the remainder of each frame member 13 occurs about fold line 24.

A connecting aperture 25 is provided in the flattened section 23 of each frame member.

When the space frame is assembled, the flattened sections of the frame members at each node are disposed in face-toface relationship one adjacent another with the connecting apertures 25 in alignment. A connecting means 27 is provided for securing the flattened sections together. The connecting means 27 comprises an assembly of a bolt 29 and a clamping plate 31. The shank 33 of the bolt is received in the aligned connecting apertures of the assembled flattened sections with the head 34 of the bolt bearing against the flattened section of the horizontal frame member 11 which is outermost. The clamping plate 31 is received on the shank of the bolt on the other side of the nodal connection and is captively retained by the nut and washer 36 of the bolt. The clamping plate 31 engages against the flattened section of the inclined frame member 6 13 which is outermost, as shown in Figures 2 and 3 of the drawings. The clamping plate 31 is substantially square when viewed along the longitudinal axis of the shank and bears against a major part of the surface of the flattened section of the outermost frame member 13. With this arrangement, the adjacent edge of the square clamping plate lies closely adjacent the fold line 24 defined between the flattened section 23 and the remainder of the frame member.

The clamping plate 31 is also of a thickness which exceeds the thickness of each of the flattened sections 23.

The frame members are assembled at the nodal connection with the flattened sections of the horizontal frame members 11 in face-to-face engagement and with the flattened sections of the inclined frame members 13 to one side thereof. The flattened sections of the inclined frame members are also in face-to-face relationship one adjacent another with the fold line of each frame member parallel to an edge of the flattened section of the preceding frame member. The inclined frame members 13 extend to a common side of the assembled horizontal frame members 11 and the clamping plate 31 is disposed on that side. The assembly of the bolt 27 and clamping plate 31 serves to retain the frame members 11 and 13 in the assembled condition.

Furthermore, the clamping plate 31 serves to support the flattened section of the outermost inclined frame member against bending when the frame member is under load (particularly tensile load). This support is provided S. because of the close proximity between the fold line of the frame member and one edge of the clamping plate, and also due to the longitudinal axis of each of the frame members 11 and 13 intersecting near or at the head 34 of the bolt bearing against the flattened section of the horizontal frame member 11 which is outermost on one side of the nodal connection. This substantial intersecting of all the axis provides a connection which is structurally stronger than P, I

II

-7one which sees those axis in an array of locations.

Bending of 'the flattened sections of the other frame members under load is also resisted by virtue of cooperation between the various flattened sections in the assembled connection.

The connection of the present invention also allows for the provision of only one connecting means or bolt. The advantages of this are many, and include a reduction in cost over systems which require more than one bolt (four are typically used) due to less parts, a reduction in manufacturing time and effort due to there being only one aperture, and a substantial decrease in labour costs due to the relative simplicity of construction. The connection of the invention is also more aesthetically appealing than a connection with a large number of bolts, due to the resultant "narrower" or less bulky connection and the number of bolts themselves. In this respect, elaborate systems for covering the connection itself, or more particularly for hiding the perhaps unsightly large number of bolts are also not needed with the connection of this invention.

From the foregoing, it is evident that the present embodiment provides a simple but high kffective nodal connection for intersecting frame members of a space frame.

It will &lso be appreciated that various modifications and alterations may be made to the above configuration without departing from the ambit of the present invention.

Claims

1. A nodal connection for intersecting frame members of a space frame, the nodal connection comprising a flattened section on each frame member, a single connecting aperture in each flattened section, the flattened sections being disposed in face-to-face relationship one adjacent another with the connecting apertures in alignment, and connecting 0 means including a single connecting shank received in the 0 °aligned apertures for securing the flattened sections together, the connecting means further including support means engaging against an outermost flattened section for supporting that outermost flattened section against bending under load.

2. A nodal connection according to claim 1 wherein the support means bears against a major portion of the flattened section of the outermost frame member.

3. A nodal connection according to claim 1 or claim 2 wherein the support means is substantially rectangular when viewed along a line corresponding to the longitudinal axis of the shank.

4. A nodal connection according to claim 3 wherein the support means is square when viewed along said line.

A nodal connection according to any one of claims 1 to 4 wherein the support means has a thickness which exceeds the thickness of the flattened section of the outermost frame member.

6. A noda% connection according to any one of claims 1 to wherein the support means is in the form of a clamping plate captively retained on said shank. 9i

7. A nodal connection according to claim 6 wherein the shank is defined by a connecting bolt received in said i connecting apertures and onto which said support means is mounted.

8. A nodal connection according to any one of claims 1 to 7 wherein the frame members are of tubular construction and the nodal ends of the frame members are crushed to define said flattened sections.

9. A nodal connection according to any one of claims 1 to 8 wherein at least one frame member is inclined to the longitudinal axis of the shank, the support means engaging against the flattened section of the outermost frame member on the side of tihe nodal connection to which the inclined frame member extends.

A nodal connection according to claim 9 wherein there are a plurality of inclined frame members extending to a common side of the nodal connection.

11. A space frame comprising frame members interconnected by a nodal connection according to any one of claims 1 to

12. A nodal connection according to claim 1 substantially as herein described in relation to the accompanying drawings. I 10

13. A space frame according to claim 11 substantially as I herein described in relation to the accompanying drawings. DATED this TWENTY FIRST day of MAY 1991 NOVAPLAS PTY LTD Applicant. WRAY ASSOCIATES, Perth, Western Australia, Patent Attorneys for the Applicant. d k L sr;-~Frm-Es~FlapmT;Fi;aLwL-_nrr~cr~r. ABSTRACT A nodal connection 21 for intersecting frame members of a space frame, the nodal connection comprising a flattened section 23 at the nodal end of each frame member 11, 13, and a connecting aperture 25 in each flattened section. The flattened sections are disposed in face-to-face relationship one adjacent another with the connecting apertures in alignment. Connecting means 27 are also provided which include a connecting shank received in the aligned apertures for securing the flattened sections together, 'and the connecting means further include support means 31 engaging against an outermost flattened section for supporting that outermost flattened section against bending under load.