Bolted lamp joint for sheet metal panels - uses bolt hole with curved edge return which fits into corresponding hole in counter sheet

摘要

The lap joint uses a nominal curved edge return (3) on one or both of the panel (1) holes. The returned edge (3) may have a stamped quarter circular profile which runs tangentially from the parent sheet (1), and has an offset which exceeds the thickness of the countersheet. The hole in the latter is enlarged to accommodate the return, to provide greater resistance to shear stresses. A nut (4) and bolt (8) is used to secure the connection, a washer (9) being incorporated to maintain a clearance with the return. Grooved nuts or bolts may be used instead of a washer.