Abstract: An apparatus for submerged culture of tissue cells in which gas is supplied to the culture medium in an upright sterilizable container through a rotating hollow shaft having a plurality of sets of radially extending blades from which the gas is discharged only along upper surfaces of the blades within a cage formed by vertically spaced hollow baffle plates connected by hollow posts through which gas is supplied to the baffle plates and is charged into the nutrient medium through porous parts of the plates.

Abstract: On two opposite long narrow sides of a guide rail (1) of a chain saw for stone are arranged slide rails (3) of plastic. The slide rails (3) are located between the side walls (18, 19) of the guide rail. A link chain (2) consists of slide elements (6) and pairs of side guide members (7, 8) which are joined with each other through links (5). The slide elements (6) lie, on one side, on a surface (15) of the slide rail (3) and have, on the opposite side, cutting plates (4). In the slide rail (3) are arranged central coolant channels (13) which are connected with the coolant feed present in the core of the guide rail (1). The side guiding of the chain (2) is assured through the side guide members (7, 8) lying against the side surfaces (11, 12) of the slide rail (3).