Abstract: A Stirling heating pump has a working piston acting upon a compression chamber and actuated by a crank drive accommodated in a housing, and a diaphragm bellows surrounding the working piston for sealing the compression chamber from the housing and having an inner hollow communicating with the former. Pressure variations in the interior of the diaphragm bellows are compensated by a pressure throttling element arranged between the compression chamber and the inner hollow of the diaphragm bellows, and a compensating diaphragm expansible in the housing and having an inner hollow communicating with the inner hollow of the diaphragm bellows serves to form a closed flow circuit.

Abstract: An arrangement for welding multi-ply staggered bags has two guiding elements for guiding a multi-ply material so that the inner ply is staggered with itself and one part of the inner ply is staggered on another part thereof, a heating aggregate which supplies hot air for welding, and a bending member arranged to bend the staggered parts of the inner ply so that they partially separate from one another and form a gap into which the hot air from the heating aggregate is supplied.