Respiratory protection mask for a compressed air breathing apparatus

p0001The invention relates to a breathing mask for compressed air breathing apparatus, comprising an automatic lung machine controlled by a control diaphragm, and an exhalation valve with an air outlet.

p0002Respiratory protection masks are usually operated in conjunction with a compressed air breathing apparatus with an automatic lung machine, which is connected to the mask body via a screw or plug connection. The air supply from a pressure reducer via a medium pressure line is controlled by a control diaphragm which is actuated by the inhalation of the mask carrier and which acts via a mechanical connection on a control valve which releases the medium pressure line as a function of the demand. This understandably highly sensitive thin membrane made of an elastic material is extremely sensitive to the environmental influences caused by extreme temperatures and aggressive media. The functional capability of the membrane can be impaired by, for example, lowering the elasticity at low temperatures and thereby adversely affecting the resistance to breathing and the sensitivity, or the membrane material being penetrated by aggressive gases, such as hydrogen sulfide or phosgene.

p0003The invention is therefore based on the object of designing an anteptic protective mask of the type mentioned in the introduction in such a way that the function of the control diaphragm is not impaired by temperature influences and aggressive media and a long service life is ensured.

p0004According to the invention, the object is achieved with a respiratory protection mask according to the features of patent claim 1. Advantageous further developments of the invention result from the subclaims.

p0005The basic concept of the invention consists in the arrangement of a cover cap which overlaps the air outlet of the exhalation valve and the control diaphragm and which has air outlet openings on the opposite side, ie, remote from the air outlet. In this way, above the control diaphragm, a rinsing space or rinsing channel is created in which uniformly heated, clean exhaled air from the mask carrier flows from the air outlet of the respiratory mask over the surface of the control diaphragm to the air outlet opening in the cover cap, thereby flushing the aggressive gases and at the same time controlling the control membrane on a constant, Or cools or heats up according to the outside temperature. This ensures an undisturbed functionality and a long service life of the control diaphragm.

p0006In the prior art according to FIG <patcit id="pcit0001" dnum="DE2720681"><text>DE 27 20 681</text></patcit> The exhaled air is optionally blown into a relatively large-volume exhalation bag made of flexible material and directed omnidirectionally around the lung automaton and out of exhalation openings. No rinse or flushing channel is provided in a substantially constant, slight distance above the control diaphragm. Therefore, there is also no deliberate flushing of the surface of the control membrane.

p0007In the prior art according to FIG <patcit id="pcit0002" dnum="DE1153258"><text>DE 11 53 258</text></patcit> Above the control diaphragm is formed a space divided by an intermediate wall, into which the exhaled air flows through a connection piece and from which the exhaled air flows through openings into the open air. In the intermediate wall, an exhalation valve is arranged at a small distance from the center of the membrane. Rinsing and temperature control of the entire surface of the membrane is not possible with this arrangement since no flushing channel is formed above the membrane.

p0008An embodiment of the invention is explained in more detail by means of the drawing in the sole FIGURE of which a respiratory protective mask with a lung machine attached thereto is shown in section.

p0009The mask body 1 of a respiratory mask has an automatic lung machine 2 for supplying the respiratory air supplied from a compressed air reservoir via a pressure reducer and a medium pressure line 3 to the mask carrier. The air supply is controlled according to the breathing rhythm via a control diaphragm 4 actuated by the inhalation, which is connected via a lever system to a control valve (not shown) for releasing the medium pressure line 3 during inhalation. Along arrows A, B and C, the arrows A, B and C show the path of the inhaled air from the medium pressure line 3 via the chamber 5 and the air inlet 6 of the lung machine as well as along the mask discs 12 to the mask carrier, while the air being exhausted in the direction of the arrows D, , E and F via the exhalation valve 7 into the open air. However, as can be seen in the drawing, the air exhaled from the mask carrier does not flow directly into the free air, but via an air outlet 8 into the washing space 10, which is delimited by a cover cap 9, above the control diaphragm 4. That is, uniformly-controlled, clean scavenging air is achieved with each exhalation cycle , Namely the exhaled air of the mask carrier, is guided over the surface of the control membrane 4. Irrespective of the outside temperature, the control diaphragm 4 is thus always uniformly tempered and thus neither restricted by its excessively high or too low external temperatures. The control diaphragm 4 is neither too rigid nor too soft, but retains its predetermined mechanical properties. The mask conditions for the mask carrier thus remain optimal even under extreme conditions. Moreover, aggressive, toxic gases such as hydrogen sulfide or phosgene, which can diffuse relatively quickly through the thin control membrane into the respiratory air area and damage the instrument carrier, are continuously washed away from the control membrane 4 by the exhaled air, thus also not affecting the control membrane But a long life and purity of the breathing air is ensured. The exhaled air (scavenging air) reaches the open air via air outlet openings 11 in the cover cap 9.

Reference list

p0010<dl id="dl0001" compact="compact"><dt>1</dt><dd>Mask body</dd><dt>2</dt><dd>lung machine</dd><dt>3</dt><dd>medium pressure line</dd><dt>4</dt><dd>Control membrane</dd><dt>5</dt><dd>chamber</dd><dt>6</dt><dd>Air inlet</dd><dt>7</dt><dd>exhalation valve</dd><dt>8th</dt><dd>Air outlet</dd><dt>9</dt><dd>Cover cap</dd><dt>10</dt><dd>WASHING ROOM </dd><dt>11</dt><dd>Air outlet openings</dd><dt>12</dt><dd>Mask discs</dd><dt>arrows</dt><dd>ABC Path of inhaled air</dd><dt>arrows</dt><dd>DEF Path of exhaled air</dd></dl>