GB2379678A

GB2379678A - A truss system

Info

Publication number: GB2379678A
Application number: GB0221137A
Authority: GB
Inventors: George Steven Robertson
Original assignee: WARD BUILDING COMPONENTS Ltd
Current assignee: WARD BUILDING COMPONENTS Ltd
Priority date: 2001-09-12
Filing date: 2002-09-12
Publication date: 2003-03-19
Also published as: IE20020740A1; DE60202916T2; GB0221137D0; ATE288976T1; DE60202916D1; EP1293619B1; EP1293619A1

Abstract

A truss system comprises bottom booms 1, rafters 2, and a plurality of web members 3 extending between the bottom booms and the rafters. Connectors 5 are used for pin jointing between the web members, the rafters and the bottom booms. Each of the rafters, bottom booms and web members are of the same lipped channel section 10 of cold rolled steel. The arms 11 of the channel section 10 are pre-drilled with a number of spaced apart holes 12, the holes in the opposite arm 11 of the channel being aligned to receive a mounting pin 13. The system comprises two different connectors 5a and 5b. In each case the connector comprises a sleeve portion 20 to receive a section 10 such as a web member 3 and at least one arm extending from the sleeve portion for pin jointing to a bottom boom or rafter. For secure mounting there are preferably two spaced-apart arms (21, 22 Fig 4). The arms of connector 5b are cranked outwardly at 23 (Fig 7) so that it can receive a second connector 5a. A pin 13, in the form of a bolt is passed through holes in the connectors and the channel section. The system can be used for any desired angle of web between a bottom boom and a rafter.

Description

"Ass System" The invention relates to truss systems and in particular to a trusss system for use in converting a flat to a pitched roof.

Conventional truss systems comprise a large number of different components which are fitted together on site. The systems are time consuming to assemble and require considerable accuracy. Site cutting of the various components is required in order to cater for even minor tolerances and variations.

There is therefore a need for an improved truss system which will overcome these problems.

Statements of Invention According to the invention there is provided a truss system comprising a bottom boom, a rafter, at least one web member for extending between the boom and the rafter, and a connector having a sleeve portion to receive a web member and an arm extending from the sleeve for pin jointing to a rafter or a bottom boom.

In a preferred embodiment a pair of arms extend from the sleeve member, the arms being spaced apart to receive a bottom boom or a rafter therebetween.

In one embodiment the arms are co-planar with the sleeve portion.

In another embodiment the arms are cranked outwardly to receive a bottom boom or a rafter together with the arms of another support therebetween.

In one embodiment the arms have holes for alignment, an assembly, with corresponding holes in a boom or rafter, for pin jointing the connector to the boom or rafter.

Preferably the sleeve portion of the connector is of channel section comprising a bottom and a pair of upstanding sides, the arms extending from the sides of the channel section.

Preferably the bottom boom and/or the rafter comprises a number of pre-drilled holes for receiving a pin for mounting a connector to a bottom boom or rafter.

In a preferred construction the bottom boom and/or rafter and/or web is a lipped channel.

In a particularly preferred embodiment the bottom boom and the rafter arc of the same section.

Ideally the bottom boom. the rafter and the web member are of the same section.

The invention also provides a trusfis system connector comprising a sleeve portion to receive a structural member and a pair of arms extending from the sleeve portion to receive another structural member therebetween, the arms of the connector being cranked outwardly.

In one embodiment the arms have holes for alignment, on assembly, with corresponding holes in a structural member.

Preferably the sleeve portion is of channel section having a bottom and a pair of upstanding sides, the arms extending from the sides of the channel section.

Brief Description of Drawings The invention will be more clearly understood from the following description thereof given by way of example only, in which :-

Fig 1 is a perspective view of portion of a roof support structure incorporating a truss system of the invention ; Fig 2 is a perspective view of portion of the assembled truss system of the invention ; Fig 3 is a cross sectional view of portion of the assembled truss system : Fig 4 is perspective view of a straight knuckle connector of the truss system; Fig 5 is an elevational view of the connector of Fig 4; Fig 6 is a perspective view of a cranked knuckle connector of the truM system; Fig 7 is an elevational view of the connector of Fig 6; Fig 8 is a perspective view of a truss beam of the truss system; Fig 9 is a view of an apex detail of the truss system ; Fig 10 is a view of an eaves detail of a truss system with parapet fixing ; Fig 1. 1 is a view of an eaves detail of a truss system with roof fixing ; and Fig 12 is a view of another caves detail of the truss system with soffit and facia support details included.

Detailed Description Referring to the drawings there is illustrated a truss system comprising bottom booms 1, rafters 2, and a plurality of web members 3 extending between the bottom

booms 1 and the rafters 2. Connectors 5 are used for pin jointing between the web members 3, the rafters 2 and the bottom booms 1.

Each of the rafters 2, bottom booms 1 and web members 3 are in this case of the same lipped channel section 10 (Fig. 8) of cold rolled steel. The arms 11 of the channel section 10 are pre-drilled with a number of spaced apart holes 12, the holes 12 in the opposite arms 11 of the channel being aligned to receive a mounting pin 13. Because the rafters, bottom booms and web members are of the same section the truss system is greatly simplified as the number of different elements is minimise.

The system comprises two different connectors, namely a straight knuckle connector 5a (Figs 4 and 5) and a cranked knuckle connector 5b (Figs 6 and 7). In each case the connector comprises a sleeve portion 20 to tclescopically receive a section 10 such as a web member 3 and at least one arm extending from the sleeve portion 20 for pin jointing, for example to a bottom boom 1 or a rafter 2. The sleeve portion 20 has lipped channel cross section for receiving the lipped channel section of the web member 3. For secure mounting, preferably there are two arms 21, 22 extending from the sides of the sleeve portion 20 and the arms 21,22 are spaced-apart to defined a gap therebetween.

In the case of the straight knuckle connector 5a the arms 21. 22 are co-planner with the sleeve portion 20 and the gap between the arms 21,22 is approximately the same as or slightly greater than the width of the channel section 10 so that the arms 21, 22 embrace the channel section 10 and are securely pin jointed to it. In the case of the cranked knuckle connector 5b the arms 21, 22 are cranked outwardly at 23 so that the gap defined between them is wider than the gap between the arms of the connector 5a to embrace not only a channel section 10 but also to receive the arms of a connector 5a therebetween, on assembly as illustrated particularly in Fig. 2.

The anns 21,22 of both connectors Sa, Sb have pre-drillcd holes 25 adjacent the free ends thereof for alignment, on assembly, with the holes 12 of the channel section 10.

A pin 13 in the form of a bolt is passed through the holes in the connectors Sa, 5b and the channel section 10 which is used for the bottom booms 1, rafters 2 and web members 3.

The system can be used for any desired angle of web 3 between a bottom boom 1 and a rafter 2. The connectors 5a and/or 5b form a pin joint at the attachment between a web member 3 and a bottom boom 1 or a rafter 2 as will be particularly apparent from Fig 2. A typical roof structure built up from the truss system of the invention is illustrated in Fig 1. Even with such a relatively simple structure the variations in the web angles wilt be apparent. Using the truss system of the invention a wide variation in web angled can be catered for using the same components.

Various roof details that are formed using the truss system of the invention are illustrated in Figs 9 to 12.

Fig 9 illustrates an apex detail in which connectors 5 are used to pin joint rafters 2 at the apex. A top tie 30 extends between the rafters 2 and the ends of the adjacent web members 3 as extended by the connectors 5.

Fig 10 illustrates an eaves detail for parapet fixing in which a bottom boom 1 is secured directly to an existing roof for conversion of a flat roof to a pitched roof.

An eaves detail for a roof fixing is illustrated in Fig. 11. A holding down cleat 35 is stitched to the side of the bottom boom 1.

An eaves detail including soffit and facia supports is illustrated in Fig 12. A bottom boom 1 is attached to an eaves beam 40 using a connector 45. The connector 45 has a sleeve 46 to receive the bottom boom 1. and outtumed arms 47, 48 which are bolted to the eaves beam. A clear 49 is also provided.

The pin jointed truss system of the invention is lightweight and provides a cost effective flat to pitched roof conversion system particularly in clear span (unsupported) applications of up to 12 metres or for larger spans in which support can be provided by the existing roof. The truss system is versatile and can be used in conjunction with any suitable cladding system. The components of the truss system are pre-fabricated and standardised for quick and simple assembly. The components are lightweight and can be readily assembled on a roof or on the ground and easily handled into position is avoided for clear span systems. Disruption to a building or its occupants, The invention is not limited to the embodiments hereinbefore described which may be varied in detail.

Claims

Claims 1. A truss system comprising a bottom boom, a rafter, at least one web member for extending between the boom and the rafter, and a connector having a sleeve portion to receive a web member and an ann extending from the sleeve for pin jointing to a rafter or a bottom boom.
2. A truss system as claimed in claim 1 wherein a pair of arms extend from the sleeve member, the arms being spaced apart to receive a bottom boom or a rafter therebetween.
3. A truss system as claimed in claim 2 wherein the arms are co-planar with the sleeve portion.
4. A truss system as claimed in claim 2 when the anns are cranked outwardly to receive a bottom boom or a rafter together with the anns of another support therebetween.
5. A truss system as claimed in any preceding claim wherein the arms have holes for alignment, on assembly, with corresponding holes in a boom or rafter, for pin jointing the connector to the boom or rafter.
6. A truss system as claimed in any preceding claim wherein the sleeve portion of the connector is of a channel section comprising a bottom and a pair of upstanding sides, the arms extending from the sides of the channel section.
7. A truss system as claimed in any preceding claim wherein the bottom boom and/or the rafter comprises a number of pre-drilled holes for receiving a pin for mounting a connector to a bottom boom or rafter.

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8. A truss system claimed in any preceding claim wherein the bottom boom is a Upped channel.
9. A truss system as claimed in any preceding claim wherein the rafter is a lipped channel.
10. A truss system as claimed in any preceding claim wherein the web member is a lipped channel.
11. A truss system as claimed in any preceding claim wherein the bottom boom and the rafter are of the same section.
12. A truss system as claimed in any preceding claim wherein the bottom boom, the rafter and the web member are of the same section.
13. A truss system substantially as herebefore described with reference to the accompanying drawings.
14. A truss system connector comprising a sleeve portion to receive a structural member and a pair of arms extending from the sleeve portion to receive another structural member therebetween, the arms of the connector being cranked outwardly.
15. A connector as claimed in claim 14 wherein the arms have holes for alignment, on assembly, with corresponding holes in a structural member.
16. A connector as claimed in claim 14 or 15 wherein the sleeve portion is of channel section having a bottom and a pair of upstanding sides, the arms extending from the sides of the channel section.

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17. A truss system connector substantially as hereinbefore described with reference to the accompanying drawings.