Section bar for frame of walls

A frame structure comprising at least a first section bar comprising at least one main wall and at least two side walls, each of said at least two side walls comprising at least a first segment departing from a respective first end of said at least one main wall in a transverse direction or substantially perpendicular to the plane of the main lying or extension of said at least one main wall, so that the first segments of said at least two side walls define with said at least one main wall a substantially U-shaped configuration, each of said at least two side walls including at least a second segment extending from the respective first segment and inclined relative to the latter in such a way that the second segments have their respective free longitudinal ends at a first distance less than the second distance between the respective proximal ends or the respective ends of connection with the or continuation of the respective first segment, wherein each of said at least two first segments of said side walls is provided with at least a free end or edge curved in whole or in part, wherein each of said at least two side walls of said first section bar defines at least one raised portion and wherein one or more through openings are delimited in said raised portions for the connection by way of connective means of said section bar with other components of said frame structure,

• and at least another section bar connected to said at least one first section bar by means of connective means,
• said another section bar comprising at least one main wall and at least two side walls, each of said at least two side walls comprising at least a first segment departing from a respective first end of said at least one main wall in a transverse direction or substantially perpendicular to the plane of the main lying or extension of said at least one main wall, so that the first segments of said at least two side walls define with said at least one main wall a substantially U-shaped configuration, each of said at least two side walls including at least a second segment extending from the respective first segment and inclined relative to the latter in such a way that the second segments have their respective free longitudinal ends at a first distance less than the second distance between the respective proximal ends or the respective ends of connection with the or continuation of the respective first segment, wherein each of said at least two side walls of said another section bar defines at least one raised portion and wherein one or more through openings are delimited in said raised portions for the connection by means of connective means with said first section bar, wherein said at least one second inclined segment has two side sections or portions spaced apart from each other so as to define a window (W) between said side sections or portions and the edge defined by said first segments in the area between the two side sections or portions,
• wherein said first section bar is engaged in the insertion zone (IZ) defined between two aligned windows (W) formed on two flanks of said another section bar.