Closed-cycle breathing equipment

US5038772A · kind A · utility

Assignee

• DRAGERWERK AKTIEGESELLSCHAFT · DE

Inventors

• Ernst-Gunther Kolbe · Mölln, DE
• Norbert Kollenbrandt · Berkenthin, DE
• Hasso Weinmann · Lübeck, DE
• Wolfgang Drews · Bahrenhof, DE
• Karsten Vogeler · Brunsbek, DE
• Hans Fiedler · Obertshausen, DE

Key dates

• Filing date: Jun 20, 1989
• Grant date: Aug 13, 1991
• Expiry date: Jun 20, 2009

Classification

• Technology area (CPC A): Human Necessities
• CPC primary: A62B7/10
• WIPO field: Other consumer goods
• WIPO sector: Other fields

Abstract

A closed-cycle breathing equipment and gas mask for operation under pressure with a pressurized air source for respiratory air and with an air bag being under prestress during the inspiration phase includes an arrangement where the prestress is decreased by a control element recognizing the expiratory phase and so as to support respiration during the expiration phase. A pneumatic control valve is used which can switch connections between the inspiration and the expiration phase and which is directly controlled by the difference between the exhalation pressure and the pressure in the air bag. The control valve connects the pressurized air source with the air bag during the inspiration phase and during the expiration phase it interrupts the connection due to the occurring dynamic pressure of the pressurized air from the pressurized air source and thus actuates a pneumatic adjusting element so that the mechanical prestress at the air bag is reduced.