| 摘要 |
The belt-fastener is cut from sheet metal strip of substantially constant width and the U-shaped elbowed portion of the fastener which forms a hinge-knuckle is folded in two in the transverse direction. The two folded sides are applied against each other in a plane located at right angles to the general plane of the clamping tongues of the fastener and form a progressive junction with the edge of each tongue. The hinge-knuckles are thus endowed with enhanced mechanical strength and provided on each side with a free space for positioning the hinge-knuckles of the opposite row. |
