Abstract: A sheet metal profile member (22) for the construction of a frame structure for a box-shaped casing for ventilation or air treatment devices. The sheet metal profile member has a substantially square cross-section with an internal cavity (23) and a guide flange (44), which is retracted in the region of an external corner edge (22a), so as to enable interconnection of adjoining frame structures both vertically and horizontally by means of a guide engagement rod (20).

Abstract: A frame structure for the construction of a box-shaped casing, in particular for air treatment devices. The frame structure comprises straight profile members (22), on the one hand, and corner elements (50,52) with three mutually perpendicular protrusions, each being connectable to one of said profile elements, on the other hand. Each corner element consists of two parts, namely an external part (50) including the external portions (50a, 50b,50c) of said protrusions and an internal part (52) including the internal portions (52a,52b,52c) of the protrusions. Said protrusion portions together form a closed cross-section fitting internally into the likewise closed cross-section of the profile members (b 22). The profile members can be slid onto the corner element protrusions while simultaneously securing the external and internal corner element parts (50,52).

Abstract: To allow a large built-in volume ratio of a vane type compressor, the outer circumferential surface of the rotor is provided in each working chamber with an indentation located next to the leading one of the two vanes partly defining the chamber, thereby increasing the through-flow area of the outlet space of the chamber through which it communicates with the stator's outlet port during the exhaust of compressed gas from the chamber.