| 摘要 |
<p>1534297 Purlin assembly METAL SECTIONS Ltd 13 Aug 1976 [29 Aug 1975] 35639/75 Heading E1K A composite purlin is formed of a plurality of sections 15-21 connected together end to end by overlapping joints secured by fasteners e.g. nuts and bolts. At each joint a cleat is provided for securing the purlin to other roof structures. The distanceγ<SP>2</SP> between the centre line of the end joint cleat and the inner end of the terminal sections 15, 21 is not less than the distanceγ<SP>1</SP> between the said centre line and the outer end of the next adjacent inner sections 16, 20 respectively. The corresponding distancesγ<SP>3</SP> in the other joints in the purlin being equal and less thanγ<SP>2</SP>. Preferablyγ<SP>2</SP> is greater thanγ<SP>1</SP>. The sections may be of Z-shaped cross section. The cleats may be short angle section elements with one flange welded to other building parts and the other flange secured at the joint by coach bolts engaging in square holes.</p> |
