A breathing apparatus includes: a vessel member having a mouth piece and internal influx chamber; a tubular communication member having opposite ends connected respectively to the intake and outgo ports of the vessel member in such a manner that the vessel member and the communication member define a circular passage for a respirable gas; an oxygen-supplying mechanism for supplying the circular passage with the respirable gas; a pair of check valves, disposed respectively at the intake and outgo...

The invention is directed to a breathing valve for patients requiring humidication and filtration of breathing air inhaled via tracheostomas and tracheal tubes. The breathing valve includes a valve body, a filter removably placeable inside the valve body, a cup-shaped cap attached over the opening of the valve body and a disc-shaped membrane disposed in front of the filter in the path of the inspired air. The breathing valve is intended to be a complete system. The system can be easily disassemb...

A powered respirator comprises a motor-driven fan unit drawing air through an upstream filter for delivery to a facepiece. Operation of the fan motor is controlled in response to a differential pressure sensor tapped in across the fan unit so as to reduce the fan throughput in response to an increase in the pressure differential and to increase the fan throughput in response to a decrease in the pressure differential, and thereby match the delivery of air to the breathing demand of the wearer. T...

A mixed gas breathing apparatus reversibly switchable between open circuit and closed circuit systems. Three embodiments show three different levels of redundancy: nonredundant, bi-linear redundant and fully redundant. The counterlung minimizes the static lung loading and thus decreases breathing resistance. Manual control system is readily accessible and allows control of addition of the breathing gases.

A breathing mask is provided which comprises an exhaling valve disposed in an opening of the breathing mask wall. The exhaling valve includes a thin diaphragm which is adapted to be moved by the breathing pressure during inhaling and exhaling either towards or away from a sealing seat. To provide a less expensive breathing mask whose exhaling valve safely closes in particular in dust-particle-containing air and which nevertheless involves low opening and closing pressures, the diaphragm is provi...

A closed circuit breathing apparatus with a simplified start-up procedure. The demand valve diaphragm (38) has in it a one way valve (51 and 52) that allows exhaled breath to escape from the apparatus. Movement of the diaphragm reciprocates a latch (63) through a series of stops (65 to 68). When the user inhales for the second time, the latch (63) escapes from the last stop (68), a spring (69) is released, the one-way valve is clamped shut by a plate (55), and a probe (73) releases a catch (35) ...

A breathing exerciser comprising an inflatable member, and a holder having a proximal end for placement in a user's mouth and a distal end for retention of the inflatable member. The holder has a main lumen extending through the holder between the proximal and distal ends and communicating with the inside of the inflatable member. The holder also has an opening communicating between the main lumen and the outside of the holder intermediate its proximal and distal ends, in order that inflation an...

Underwater breathing apparatus including a diver worn back pack having a hard outer shell and a soft flexible undersurface to conform to the diver's back. Breathing bags positioned between the undersurface and outer shell are connected to the undersurface so as to extend down the diver's back and be coextensive with his lungs. Gas circuit components are mounted on the inside of the shell. The apparatus makes contact with the diver's back, at a small area on the upper portion of his back, and, at...

Breathing apparatus which incorporates a sensing device operable to adjust the amount of breather's exhaled gas captured in a gas collector section as a direct function of flow rate and volume of the previous inhalation. The amount of exhaled gas captured is sufficiently low in carbon dioxide (CO.sub.2) content to permit rebreathing on the next inhalation, at which time the sensor again adjusts the volume of exhaled gas to be captured. In the one embodiment, a fire fighter's breathing system is ...

A respiratory apparatus, which receives exhaled gas from a user, removes carbon dioxide from and introduces oxygen into the exhaled gas, to present a breathing gas to a user. A respiratory flow transducer in the respiratory apparatus is subjected to the breathing gas demand of the user. Oxygen is introduced into the breathing system by an oxygen flow regulator connected to an oxygen supply inlet. The respiratory flow transducer and the oxygen flow regulator are connected by a linkage. The linkag...