Abstract: A piston machine has at least one axially movable piston in a cylinder. At the top of the cylinder there is at least one intake valve and at least one exhaust valve. An injection port is provided in a cylinder wall between a lower and upper point of reversal of the piston. The air is suitably supplied from an air chamber between the cylinder wall and a lower narrowed part of the piston. For adjustment to the engine load, this air chamber may be connected with an extra air chamber suitably having an adjustable volume. Likewise, the engine may be provided with a rotary valve for supplying the air to the cylinder. This provides for a faster exhausting of the combustion gases and a better degree of filling of the cylinders.

Abstract: A piston machine with at least one axially movable piston in a cylinder is designed with a force conversion mechanism implying sinusoidal piston movement by rotation of the power input or power output shaft of the machine, depending on its application. As the pistons of the machine are fastened perpendicularly to a crosshead yoke (5) at their preferably light, cylindrical piston-rods (2,2′), in which two crosshead slides (14,14′) each are provided on a crank pin journal (7,7′; 8,8′) which is synchronized to perform rotation with mutual opposite directions of rotation (indicated as arrows). This arrangement causes the crosshead slides longitudinally in the yoke to move in exact mutual opposition and to reverse their direction of movement at the exact same time. Thus, the lateral pressure on pistons is completely eliminated and without any addition of any extra balancing mechanism there may be achieved a complete outbalancing of the reciprocating and rotating masses in the machine.

Abstract: A framework construction, e.g. for buildings, is made with intercrossing beams (2, 4, 4') of profiled plate material, the beams being prepared with side incisions (14) enabling them to be joined crosswise in a common plane.