GB2093887A - Portal frame - Google Patents

Abstract

A portal frame is formed from a number of individual preformed metal structures 10, 11, 12, 13, 14, 15, 16 secured together. Each structure comprises parallel members 34, 35 joined by tie members 36, 37, the end tie members 37 being at an angle to the parallel members to enable the metal structures to be secured together at their ends. <IMAGE>

Description

SPECIFICATION Roof structures This invention relates to roof structures particularly for large industrial buildings and of the kind comprising upright columns and roof trusses formed as metal structures secured together to make up roof assemblies.

It is usual for the metal structures to be constructed individually according to the design of the building and often the work of bolting or welding the parts together takes place at the site at which the building is to be erected, although sometimes it is convenient to make whole assemblies in a factory and transport them to the site in completed or partially completed form.

It is undesirable that skilled work such as welding should be carried out at the site but the carriage of large assembly from a factory to the site is also inconvenient.

It is the object of the invention to provide a roof structure formed from metal structures and in which assembly on site is simplified and the transport of the structures is convenient since there is no necessity to carry large assemblies.

According to the invention there is provided a roof structure formed from a number of individual preformed metal structures, secured together, each structure comprising two parallel members joined by tie members, each of the end tie members on the structures being at an angle to the parallel members, to enable the structures to be secured together at their ends.

According to a further aspect, the invention relates to a metal structure for use in a roof structure as specified in the preceding paragraph, comprising a pair of parallel members connected by tie members, each of the end tie members being at an angle to the parallel members.

Preferably the metal structures have end tie members equally and oppositely inclined to the lengths of the parallel members.

Conveniently some of the structures are elongated and some short, the latter forming junction members between elongated structures at positions where the two adjacent structures are angularly disposed with respect to one another.

The invention will now be described by way of example with reference to the accompanying drawings in which Figure 1 is a diagrammatic representation of a roof structure constructed in accordance with the invention Figures 2, 3 and 4 are similar views of alternative roof structures Figure 5 is a side elevation view of a metal structure used in the roof structure of Figure 1 Figure 6 is a metal structure of different size Figure 7 is a short junction structure and Figure 8 is a further form of junction structure Referring to Figure 1 this shows a roof structure constructed from metal structures of the kinds shown in Figures 5 and 6. These are two columns formed by single upright metal structures 10 and 11 and these support straight metal structures 1 2 and 13 which are inclined to one another at a shallow angle.The structures 10 and 12 are directly bolted together as are the structures 11 and 13. Between the structures 12 and 13 however is a junction structure 14 of generally triangular shape being of the kind shown in Figure 7. At the bottom of each column formed by the structures 10 and 11 are further junction structures 1 5, 1 6 each being of the kind shown also in Figure 8.

The connections between the metal structures are by bolting and further reference will be made to this later.

Figures 2 shows an alternative roof structure wherein columns are formed by metal structures 10 and 11 and these support metal structures 17, 18 which are the same length as the structures 10 and 11. Otherwise this roof structure is the same as the Figure 1 construction having junction structures 14, 15 and 16. It illustrates however how different sizes of roof structure can be produced using standard components.

Figure 3 shows a further alternative roof structure wherein upright columns are formed by metal structures 1 9, 20 and these support pairs of metal structures 21, 22 23, 24. These join at the centre of the span by means of a junction structure 25. The straight upwardly inclined arms of the span are made up from the pairs of structures 21, 22, 23 and 24 which are bolted directly together the ends being of complementary opposite angles. The junction member 25 is somewhat longer than that shown in Figure 7.

Junction members 1 5, 1 6 are used at the foot of the two columns respectively.

In the Figure 4 construction upright columns are formed by metal structures 25, 26 and the span is formed by two pairs of structures 27, 28, 29, 30 similar to those in the Figure 3 construction. To extend the centre junction a rather longer junction member 31 is used.

All these constructions shown in Figures 1, 2, 3 and 4 illustrate the fact that roof structures can be formed using standard components. These are three sizes of normal elongated metal structures and four sorts of junction structures although three of them are the same but having slightly different lengths. These are the structures 14, 25 and 31.

It is obvious that many different lengths can be produced but for ease of production it is very desirable to limit to a small number of standard sizes. The structures all have inclined ends and an optimum angle of 51.250 has been chosen so that the span is inclined to the horizontal at an angle of 12.50. The invention is not limited to such angles but these are considered optimum for a wide range of building structures.

Referring to Figures 5, 6, 7 and 8 these show the individual metal structures. Figures 5 and 6 show elongated structures of different lengths.

Each comprises a pair of parallel tubes 32, 33, 34, 35 of appropriate length. These are joined by webs 36 which may be made from tube or strip metal. At the end the tubes are joined to T section members 37. These are fitted so that the cross of the T is presented outwardly. They extend at angles of 51.250 to the parallel tubes 32, 33 or 34, 35 and are provided with holes for bolts whereby the individual metal structures can be secured together.

Each metal structure is preformed before assembly into a building structure and is preferably welded together Although tube and Tsection members have been described alternative sections can be used as required, and where tube is used this may be of circular section or any other appropriate section.

In Figure 7 the short junction structure is shown. This has parallel tubes 38, 39 joined at their ends by T-section members 40, These members 40 are at complementary opposite angles to their parallel tubes 38, 39 and in the case shown the angle to the horizontal is 63.750.

Preferably however there are a minimum number of standard units and for example there may be three sizes of these junction members.

Figure 8 shows the junction member for the base of a column or however the equivalent situation. This comprises a pair of parallel tubes 41, 42 joined at their ends by T-section members 43, 44. The member 43 is perpendicular to the parallel tubes 41,42 whereas the member 44 is at an inclined angle. Again a minimum number of standard structures are used.

Where these structures of the kind shown in Figure 8 are used at the bottom of upright columns they may be connected by pins to concrete or other foundations. Alternatively they may be wholly or partly embedded in concrete foundations.

By this arrangement it is possible to build up a large number of alternative roof structures using a minimum number of standard components.

Furthermore the individual metal structures may be easily transported and secured together by simple bolting connections when on site.

Claims (6)

1. A roof structure formed from a number of individual preformed metal structures, secured together, each structure comprising two parallel members joined by tie members, each of the end tie members of the structures being at an angle to the parallel members, to enable the structures to be secured together at their ends.

2. A roof structure as claimed in Claim 1 in which each of the metal structures has its opposite end tie members equally and oppositely inclined to the lengths.

3. A roof structure as claimed in Claim 1 or Claim 2 wherein some of the structures are larger and some shorter, the shorter structures forming junction members between longer structures of positions where two adjacent structures are angularly disposed with respect to one another.

4. A metal structure for use in a roof structure as claimed in any one of Claims 1 to-3.

5. A roof structure substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

6. A metal structure for use in a roof structure substantially as hereinbefore described with reference to and as shown in the accompanying drawings.