Lung-operated breathing gas valve.

The invention relates to a regulator for breathing apparatus according to the preamble of claim 1.

The regulator for breathing apparatus are definitely for the user of the respirator, which then is always in a dangerous, definitely for him busy environment, secure the air supply. This must also be ensured if there should be a failure of the main pressure reducer, in which the tank pressure is reduced.

From US-PS 39 57 044 a respirator is known, which is supplied from a bottle of compressed air or oxygen. The device operates in two pressure stages, in the last of the regulator, which conducts the respiratory gas directly to users. The first stage comprises two parallel-connected pressure regulator, the operating pressure reducer and the Reserve reducer, in which the pressure of the breathing gas is appropriately reduced to regulators. The pressures behind the two pressure reducers differ insignificantly.

The operating pressure reducer sets the cylinder pressure to an intermediate pressure of about 6 bar down. This is a medium pressure line a connected to a mask lung automatic valve, the regulator, supplied. A check valve in the pressure line means allows flow only from the operating pressure regulator to regulator. The regulator allows the gas flow to the user in accordance with its breaths. In parallel with the operation of the pressure reducing valve replacement pressure reducer is arranged, the reserve pressure is adjusted to about 9 bar. The disposal of the replacement pressure regulator is connected via a spare line that contains a normally closed shut-off valve with automatic means of the pressure line downstream of the check valve. The automatic shut-off valve is pneumatically operated, also features a provided with different piston areas spool. Meanwhile, larger, acting in the closure direction Piston area is derived between pressure reducer and check valve, acted upon by the medium pressure. The smaller, acting in the sense Öffenenden piston surface is acted upon by the replacement medium pressure. The matching of the surfaces causes the closure of the check valve under normal conditions. but collapses in case of failure of the operating pressure reducer of the medium pressure, so the now vast reserve medium pressure opens the check valve, and the reserve line to the regulator gas flowing maintains the supply. At the same sounds with each breath a warning signal. The check valve is required in this state, so that the replacement intermediate pressure does not reach the reverse current to the larger piston surface and can lead to a renewed occlusion of the check valve or its swing.

A switched directly to the tank pressure pneumatic switching valve switches definitely, even if the operating pressure reducer should have no defect, when it falls below a minimum pressure, a bottle, the spare line so that there is a warning signal.

This residual pressure Warner is not content with the present object; It is known in many variations.

For the task at hand, this known safety circuit with an additional full pressure reducer and check valve not only very costly but also means considerable weight to the user, which he might have to lug around entering failure constantly using only one. Moreover, the replacement pressure reducer which is a complicated device yes and unused is usually only in reserve, in case of emergency easily also fail.

The invention is based on the task of a regulator for breathing apparatus of the aforementioned type, in which there is a well in case of failure of the pressure reducer, in which the tank pressure is reduced to the medium pressure suitable for the regulator, can not lead to the endangering of the device user, by simple structure even safer, simpler and easier to make in the operation and the maintenance.

This object is achieved in that the tilt valve as normal access for the breathing gas in the medium pressure _PMD can be bypassed to the machine housing and the breathing gas in the high pressure p_HD a piston valve which, via a control line with the P_MD connected and p_MD compared to the _PHD closed in case of failure of the p_MD opens, flows directly into the machine housing.

In a simple embodiment, the spool valve includes a valve housing having a stepped piston with the _Pmu opposite major surface and having a p_HD opposite smaller area carrying on this a valve cone which forms a seat as an opening to the interior of the machine housing, a high pressure valve. In addition, the valve housing may comprise a spring, which lifts the differential piston in the opening direction of the high-pressure valve.

The advantages achieved with the invention consist particularly in the fact that here a simple, safe, clear device with only one pressure reducer that requires no additional check valve in the gas supply line between the existing pressure reducing valve and the regulator, presented. It provides in spite of the simple structure but ensure that the device user is always with sufficient breathing air flow, which then will flow directly from the high pressure breathing gas source, such as the compressed gas cylinder, supplied in case of failure of the pressure reducer.

An embodiment of the invention is illustrated in the drawings and will be described below.

The machine housing 1 the regulator has the nozzle 2 to breath connection for the user, for example on a respirator. Opposite the outside it is finished in a conventional manner via a membrane 3, which is protected by a perforated cover 4 against external influences. The supply of the breathing gas is carried out by a terminal 5, which is closed to the interior of the machine housing 1 by a spring-loaded tilt valve 6th His rocker arm 7 is activated by the membrane 3rd

A spool valve 9 is connected via a control line 8 to the terminal 5 in front of the tilt valve 6 and opens connects a high pressure port 15 with the interior 10 of the machine housing 1. The stepped piston 11 is located in a valve housing 12 with a larger surface 13 which via the control line 8 from the reducer fitting medium pressure _PMD , whereas it with its smaller surface 14 which supplied through the high pressure port 15 pressure bottle _PHD bears. The differential piston 11 carries on the lower surface 14 of a valve cone 16 which forms a seat 17, opening to the interior 10, a high pressure valve 18th A spring 19 lifts the stepped piston 11 in the open position of the high pressure valve 18th

In normal operation, is connected to terminal 5 of the medium pressure p_MD the functioning of the pressure reducer. By negative pressure generated when breathing through the nozzle 2 the tilt valve 6 is operated via the membrane 3; necessary for respiration respiratory air flow, and then flows through the nozzle 2 the devices were used.

With the failure of the pressure regulator in the breathing gas supply stops the medium pressure p_MD at terminal 5 together. The supply of the device user via the normal route is no longer possible.

The emergency through the piston valve 9 comes into operation. The normal operation of the medium pressure_PMD over the larger surface 13 of the stepped piston 11 against the force acting on the smaller surface 14 together with the spring 19, high pressure p_HD closed high-pressure valve 18 opens.

The supply of the device user with breathing gas occurs now bypassing the lung controlled tilt valve 6 directly from the high pressure port 15 through the high pressure valve 18th