Abstract: A pneumatic sealing system for a gas mask, which seals the mask to the face of the user by using a pump that employs air from inside the gas mask to variably inflate a mask seal during the breathing cycle. A double diaphragm pump, which has a driving diaphragm and a driven diaphragm, is connected to the inflatable mask seal via a hose duct. The double diaphragm pump is driven by the pressure difference inside the gas mask. During inhalation, the driving diaphragm fills with ambient air and the driven diaphragm fills with filtered air. During exhalation, the driving diaphragm and the driven diaphragm compress, releasing and trapping air in the mask seal.

Abstract: A breath responsive filter blower respirator system for a gas mask including a pressure and control device, such as an optoelectric device and/or a pressure sensor, to control the air flow produced by an air blower. The optoelectric device detects the position of the mask's outflow valve. The pressure sensor measures air pressure in the mask relative to ambient air or the absolute air pressure in the mask. During exhalation, the pressure detector detects an increase in air pressure in the mask and/or the optoelectric device detects the outflow valve in an open position, and then signals the central processing unit to signal the air blower to reduce speed. The reduction in speed reduces air flow in the mask and lowers air pressure in the mask.

Abstract: A self-sealing protection filter port for gas masks prevents contamination of the inner-environment of the mask during exchange of filters and therefore increases safety. A biased valve closes the air inlet to the port when the protection filter is not installed. As a new filter is inserted, the valve is forced open, allowing filtered air to flow through the air inlet to the user. The protection filter engages the filter port using a retaining element. The self-sealing protection filter in a protection mask having an internal close-biased valve is installed in the standard protection filter port of the mask.