Sheet metal duct mfr. rolling machine - has complete bend joined from segments by external rolling of ribs on mandrel

摘要

The sheet metal segments are joined by their edges under closing rollers. The segments are joined on their longitudinal edges to form a duct bend. The segments of duct bend are formed so that they have narrower and wider part which on joining form a complete bend. The duct bend has four segments (1, 2, 3, 4) joined by externally projecting rolled ribs (5). The segments are provided with a stabilising depression (7) and bolted together. The bend parts are made from rectangular piece of sheet metal cut from continuous strip. The segments are formed on a mandrel and closed by rollers.