Method of and apparatus for making a bottom of a tubular section for formation of a bag or sack

Abstract

In a method and apparatus of making the bottom of a flat tubular section, a tubular section is transported by a conveyor at a continuous rate in an alignment transversely to a longitudinal direction of the conveyor, with a first suction unit partially opening one end of the tubular section. Subsequently, a spreader unit is inserted into the partially open end of the tubular section and moved in a first phase in a substantially linear horizontal motion toward an end position in which the spreading unit conforms to fold lines of a finished bag bottom. In a second phase, the spreader unit swings from a substantially horizontal alignment into a substantially vertical position about a horizontal pivot axis by way of a compound motion in which a movement of the spreading unit into the end position is superimposed by a movement into the vertical position, thereby forming the open bag bottom. Thereafter, the spreader unit is withdrawn from the bag bottom while maintaining the formed bag bottom in vertical disposition by means of a second suction unit for further processing.

Dependencies are inferred from the claim text.