Filter unit with a filter block, a damping layer and a housing, and process of manufacturing such a filter unit

A breathing apparatus comprising:

• a filter unit comprising:
• a rigid pot with a base and a tubular side wall;
• a cover cooperating with the pot such that the pot and the cover together form a housing;
• a rigid filter block with two end faces and a shell surface between the end faces, the housing surrounding the rigid filter block with a gap between the tubular side wall and the shell surface, the rigid filter block being configured to filter out at least one gas and/or particles from a gas mixture flowing through the rigid filter block;
• and a one-piece deformable damping layer comprising:
• a flat inner area;
• and a corrugated outer area, wherein the inner area of the deformable damping layer is located between one end face of the rigid filter block and the base of the pot, wherein the outer area of the deformable damping layer circularly surrounds the inner area, wherein the outer area of the deformable damping layer is circumferentially connected to the inner area, wherein the outer area of the deformable damping layer is located in the gap, and wherein the other end face of the rigid filter block is adjacent to the cover;
• and
• a filter unit carrier configured to rest against a head of a human, wherein the filter unit is releasably connected or connectable to the filter unit carrier.

A process of manufacturing a filter unit, the process comprising the steps of:

• providing a rigid pot with a base and a tubular side wall;
• providing a cover;
• providing a rigid filter block with two end faces and a shell surface, the rigid filter block being configured to filter out at least one gas and/or particles from a gas mixture flowing through the rigid filter block;
• providing a deformable one-piece damping layer in a form of a flat object;
• stamping a corrugation into an outer area of the deformable damping layer to produce a corrugated outer area of the damping layer which circularly surrounds an inner area of the damping layer;
• placing the deformable damping layer on the pot and subsequently moving the deformable damping layer into an interior of the pot such that the inner area of the damping layer is moved towards the base of the pot and the corrugated outer area of the damping layer is adjacent to the tubular side wall of the pot;
• moving the rigid filter block into the interior of the pot such that the inner area of the damping layer is located between the base of the pot and an end face of the rigid filter block, and the corrugated outer area of the damping layer is located in a gap between the tubular side wall of the pot and the shell surface of the rigid filter block;
• and
• connecting the cover to the pot such that the cover and the pot together form a housing which surrounds the rigid filter block and the damping layer.