The present invention refers to a valve unit, preferab- ly for air of that kind that is indicated in the preamble of the accompanied main claims.

Working environments of kind that are dangerous to health are very diversified. In most cases totally protective clothing is required to wear by the person, who is to make an effort in those usually closed spaces. Examples of such ones are nuclear power plants, chemical works, research laboratories, isotope laboratories, wells, of type cesspools and manure wells.

To its character the contaminated environment can be as well corrosive, as radio active or contain biological ac- tive harmful organisms and appear as gases or dust.

Under the circumstances related above, not merely speci- fic demands on the protective clothing material and the shape of the clothing, but just as least important is the functionality of the valve unit and the surronding equipments that are connected to the protective clothing and this to make secure and reliable supply of air for ventilation purpose into the clothing for the comfort of the carrier, and furthermore for the latter's con- tinuous and necsessary need of breathing air supplied in.

Known protective clothings have control means, which give undefined flow amounts for ventilation and admit low pressure values to the free space of the clothing, and further more the outbreathed breathing air is used as an essential component in that very flushing air that is to ventilate the protective clothing. Example of such a ventilation, where the outlet valve in the pro- tective clothing continuously drains off outwards a flush- ing amount corresponding to the outbreathed amount of air is disclosed in the patent specification DE-PS 1241713.

Protective clothings and equipment belonging to them oft- en are in readiness to be used, when accidents, and where rapid action is necessary to save human lifes or material values. It is then essential that this clothing and above all that its valve-and connecting equipment can be used in so many ways as possible, and consequently be so di- versified that change from external air supply to intern- al sort easily can be carried out. Also is essential that the flows of ventilation and breathing air can be adjusted according to the working conditions and the environment, in which the carrier of the clothing is existing. Some- times in severe situations the carrier of the clothing have to economize with the air available and in other si- tuations be able quickly, considerably to increase the supply of air into the clothing for breathing-and venti- lation purposes.

Control valve arranged in protective clothing for supply of pressure air for ventilation-and breathing purposes is de- scribed in a Swedish patent, published as No. 439588. The control valve : is here a pressure control valve essentially comprising a membrane 11 that is spring-loaded and of a handle bar arm arranged on a pressure valve 10, that sets the membrane to an appropriate position to achieve the overpressure of the clothing.

The transfer of breathing air is taking place from a non- volume defined inflated free-room 4, and that the out as- pirated air more serves as flushing air.

A carrier of a protective clothingequipped with valve unit according to the invention is always secured pure feeding air from the air supply sources, as the carrier is carry- ing breathing mask with breathing valve of free-flow helmet. In the specification 439588 is shown that breathing air, taken from the free-room 4, and consequently, is composed by mixed air by the existance of the inhalation valve 3 and the exhalation valve 5. These valves are further more spring-loaded.

The valve unit for ventilation air according to the in- vention is essentially cam-profile operated and put under a pressure of 7.5 bars.

An aim of the present invention is to achieve well- defined, by the carrier person of the clothing, adjustable and in advance by him known air flow volumes in litres per minute, and: according to the working conditions rela- ted above, adapted flows of ventilation into the protec- tive clothing and by that to attein a comfortable and'suit- ably pressurized free-room between the carrier of the clothing and the clothing itself.

A purpose is furthermore that the input air fed to the valve unit of the clothing can, alternatively depending on the circumstances, be taken from an external air supply source and be distributed by the valve unit within the clothing as ventilation air at the same time through flow takes place via an overflow passage to air-connected breathing mask/valve, being arranged to the carrier's breathing organ, or where appropriate, that internal con- tainer for compressed air, carried under the protective clothing co-operates with the valve unit and connecting components belonging to the same, in order to provide the carrierpri'marerl.ywith breathing air, when the ventilation function can be throttled or by different reasons complete- ly can be blocked.

A further purpose of the present invention is to increase the level of security in relation to what is known in the art by being able to connect alternative by-pass and switch- ing devices, that can start to function in emergency cases and especially also be used in test situations. So for ex- aple alternative components can be put in the valve unit as spindles, nozzles etc.

At a valve unit, tightenly connected to a totally protective clothing, the invention solves the aims related above by performing the valve arrangement with those special charac- terizing parts of the following patent claims.

With reference to the accompanying drawings it is describ--- ed below as example a suitable embodyment of the valve unit put in its connection accordingto the invention. In this case it is shown in Fig. l. a schematic outline of a person carrying a total- ly protective clothing with the valve unit tightenly con- nected to the clothingwall and passing through the wall, with external and internal hose connectors intended for external and internal air, Fig. 2 more in detail and partly in section an over- view of the connection of the inlets and the internal passages arranged to an interior valve house and the con- nection of a cam knob to an outer valve housing, Fig. 3 partly in section a distributing cover that, when applied by screwing against the clothingwall be means of a cover holder, clamps up the distributing cover via the intermediate fitted seal ring, and ensure the valve unit to tighteningly attachement against the clothing wall, Fig. 4 a lateral view of the cam knob attached to the outer top section of the valve housing, Fig. 4a a front view of the cam knob with marked values of air indicated as litres per minute that is to vent the protective clothing, Fig. 4b a cam knob arranged to the valve housing, part-- ly in section, showing a hole, and inside the cam knob a cam-profile path is provided, Fig. 4c a view of a horisontal section in Fig. 4b and a path of the cam-profile provided concentrically to the fulcrum of the knob and four holes in the valve housing, Fig. 5 an extention of the cam profile and the poqi- tions wherv a valve spindle with its end abutting the cam- profile, Fig. 6 an essential part of the valve unit located inside the clothing, and partially as broken up section view, and

where a displaceable spindle takes an initial position, a sealing positions- Fig. 7 a next following open seat S1 as a consequen- ce of the displacement of the spindle, and the path a first ventilation volume takes by its passage out into a distributing cover, Fig. 8 the same detailed view as in Fig. 7, but the spindle displacement to an off position of a seat S2 and the passage of air out from the channels of the spindle and via hole in the valve spindle housing, Fig. 9, detailed view in Fig. 7 and Fig. 8, but with the end position of the displacable spindle, and a seat S3 for the passage of the ventilation air via nozzles out in- to distributing cover, The Figures 6a, 7a, 8a and 9a are enlarged detail views that principally show the air passages in their positions respectively, Fig. 10 the transfer passage of the incoming feed- ing air through the valve unit at closed or open position for ventilation air, so called by-pass function, Fig. 11 the two channels and T-pieces of the distri- buting cover, In the following an embodyment will be described of a valve unit according to the invention placed in its con- text, as will be seen from Fig. 1, With 1 is designated a totally protective clothing of a modern kind with glass gauge for the carrier's sight and the valve unit 3, tightenly attached in front on the chest for safe and comfortable control. An external air source 2a provides the valve unit, via mobile hose 4 and al- ternative connecting couplings said unit, with air that is flowing through the same. This air will be divided up in the valve unit 3 as ventilation air to the clothing by means of the divert channels 7 and 7'for further passage via venti- lation hoses l1 and ll'of the clothing, which each distribu-

te the ventilation air upwards to the arms and downwards to the legs. From the valve unit 3, via transfer channel,-- air for breathing purposes emanates by an attached hose 6, (see Fig. 10), which connects to a T-piece 5, from where air, via a thereto connected pressure sensing valve 33, is carried further by means of a hose 8 to a breath- ing mask/breathing valve 10, and to which said T-piece al- so a feeding hose 9 is connected, which via a connected regulator coupling device 12 is in communication with a compressed air container 2b that the carrier person hav- ing with himself inside the clothing.

That the compressed air container is used and can be con- nected up shall be seen as an advantage and a many-sided- ness that the valve unit offers. Its use will principally be required, in the cases external air by different reasons fails to appear, by hose fracture of the hose 4, rips on the clothing 1 or the like, when the carrier must save himself in escape-situations out from contaminated space.

How this is handled in connection with the invention will later on be commented.

Fig 2 shows an embodyment of the valve unit 3 according to the invention in that a valve housing 13, sealingly attach- ed to the exterior clothing wall la, carries a controllable cam knob 19 that by means of a cover plate 21 protects a clamp ring 22 and is snapped in close to the valve housing.

The cam knob 19 protects the position defining device in- side the casing of the cam knob, as more in detail are shown from the Figures 4b, 4c and Fig. 5. In order that the cam knob 19 always with safe function and not unintention- ally will be brought out of its chosen position at a work- ing performance, four holes 24 are arranged in the valve housing 3 for reception of a spring-loaded positioning ball 23 that at the rotary motion of the cam knob finds its fix- ed rest position in one respective hole 24. By this arrange- ment the carrier of the clothing can, with advantage befo- re the carrier person takes it on, adjust desired approp- riate position that decides the air flow to the clothing.

The valve housing 13 has inside the protective clothing an arranged section that must be sealed against out-or in- flowing media, and has therefor attached around the wall opening of the clothing a thin sealing ring 34 illustrated according to Fig. 3. The ring 34 is lying over notches 36 in a distributing cover 26 mountable on the above said opening and is by that sealingly located against the clothing wall la. In known manner a good sealing is achieved by the fact that a hook-shaped fastener has been arranged around the distributing cover 26, and so performed that it clamps up the clothing wall against the valve housing 13, when a cover holder 27 is screwed on the distributing cover 26. The cover holder is by means of gasket ring, so called 0-ring sealing- ly fixed to the distributing cover, and gives here space for a chamber 11, in that part of the valve unit 3 that pro- trudes in the protective clothing, i. e. the free space 14.

Here the valve unit 3 primarily comprises a therein arranged spindle housing 25 that by means of 0-rings 38 (Fig. 6) are sealingly mounted in the space of the distributing cover 26.

A quick'coupling 15 with integreted non-return valve is threadedly fixed to the outer lower part of the valve unit 3, andan overflow channel 16 in the valve housing of the unit 3 is in communication with the chamber 17. To this chamber a communication channel 52 carrying breathing air is connected, and said channel ends in an orifice (see Fig.

10), with the arrangements 45,51 leading to the distribu- ting cover 26. To the lower part of the distributing cover is sealingly inserted a male piece of a hose coupling that enables engagement of alternative internal connecting de- vices, as an example plug 53.

In valve spindle housing 25 a displacable spindle 28 takes four different positions depending of the control of the cam knob 19. The design of the cam knob is illustrated more

in detail in Fig. 4b, 4c and in Fig. 5. In the circular in- teriour hollow space of the cam knob, a cam profile 20 is shaped, with limited, different length of extension bet- ween the profile parts, as is obvious from'the Fig. 4c. With 24 is designated the four, concentrically around the fulcrum of the knob, performed borings in the abutment surface of the valve housing 13 against the knob 19. Fig. 5 shows in lateral view an extension of the path 20a of the cam profile and il- lustrates the profile levels, which define the different end positions 09 L2 L30 L150/Lloo that the spindle end 29 can take by abutment against the cam profile part, respecti- vely.

The spindle 28 lies displacable in its longitudinal direc- tion in a valve spindle housing 25, that has inlet ports 48, communicating the chamber 17 via an anteroom of the valve spindle housing 25. In this anteroom a sealed seat Slis lo- cated with associated 0-shaped ring 39a, that seals against a nozzle A2 (see Fig. 7a). The nozzle Axis in communication with a longitudinal channel 37 in the spindle 28. A short distance in on the opposite, solid end 29 of the spindle is concentrically attached an 0-shaped ring 41. A way in on the spindle end turned towards the seat Sl is concentrically attached an 0-shaped ring 39b, that forms a seat S2 to shoul- ders in the interiour space of the spindle housing.

The spindle 28 has, perpendicular to its longitudinal direc- tion, a bored up, through channel 46, that ends in the chan- nel 37 and permits the larger flow volumes in litres per minute to pass further into the channel 37. An outlet port 49 penetrates through the spindle channel 37 upwards and ends in a transfer channel arranged in the valve spindle housing inside the bored hole 50. This hole is provided with a nozzle.

The upper opening 42 of the transfer channel in the valve spindle housing 25 leads to the hollow space in the distri- buting cover 26. From this mentioned cover, wide distributing channels 44a, 44b lead, oriented 180 in relation to each

other, the inflowing out into the free-room of the clothing for the ventilation of the same.

At an end position that the spindle 28 can take by the turning of the cam knob to the position L100 alternative- ly L150 according to Fig. 5, a turned down, longitudinal part of the spindle 28 is exposed, situated a distance in from the seat S2, whereupon at the spindle displacement a more wide passage will be opened between said spindle body part andO-shaped ring 39c, lain close to and concentrical- ly arranged around the spindle body. By this, an open seat S3 is created with shoulders in the valve spindle housing 25.

In the bore hole 50 then, depending on the flow volume in litres per minute one consider to require of ventilation air, an alternative nozzle can be put in. In the normal case one starts with a nozzle D1, giving the flow volume of 150 litres per. minute, but it can be replaced with the throttle nozzle D2 that is screwed into the opening 42 and gives 100 litres per minute of ventilation air into the clothing.

With reference to Fig. 10 is shown the path that external air flows through the valve unit and how a so called by- pass function is achieved. By this all mentioned venti- lation positions of the clothing, as well as closed po- sition of the seat S,, can be prevailing.

In order to fully be able to utilise and achieve the tech- nical effect that is manifested in creating a quickly ad- apted, comfortable climat for the carrier of the clothing, it is shown in Fig. 11 the inserted angle tees 7,7 arrang- ed in each of the distributing channels 44a, 44b and in the angle tee 5 with pressure sensing valve 33.

According to Fig. 10 the external air fed in via hose 4 passes the channel 16 and the chamber 17, at for example closed seat S,, whereby an opening 45 in the chamber com- municates the chamber 51 and 52 arranged in a lower part

18 of the interiour section of the valve housing 13 and- connects to the feeding hose 6 for breathing air. Natural- ly, the reverse passage way for breathing air is possible, by, according to Fig. 11, internal air being connected to the angle tee 5 via shown hose 9 and regulator 12 and the air source 2b.

The pressure constituting the control pressure is 7.5 bars for the displacement of the spindle towards the path of the cam profile. This pressure is such that it easily is over- come for the displacement of the spindle in direction to- wards the seat SI. In the case that pressure reduction oc- curs in the chamber 17, for exemple at rupture of the hose 4, a reverse motion of the spindle 28 to the seat S1 takes place not as a consequence of prevailing pressure differen- ces in, a channel 37, but readjustment by restoring of the cam knob of the carrier to position L 0 is required and re- commended.

The many-sidedness of the valve unit by its technical de- sign manifests in case of emergency. In this connection the non-return valve 15starts to function, and does not per- mit intake into the valve unit of contaminated air, simul- taneously as feeding air, automatically or manually, quick- lyis transmitted from the compressed air container 2b. This is possible as a pressure reduction sensing valve 33 is connected at the angle tee 5 on the feeding conduct. The feeding pressure 7.5 bars is catered for in this case by a regulator 12 arranged to the container 2b.

The present valve unit has been manufactured and has been tested under different conditions, and aims to constitute an industriel product to form an integral part of modern protective clothings and in that respect at least to stand up to the requirements of reliability that is claimed, when protective work is concerne.

In severe traying situations for the carrier of the protec- tive clothing the simplicity in the control and the accessi-

bility of the cam knob in the middle of the chest are very important, at the same time as the knob is more protected against impacts and easy to grasp for the carrier.

Integrated details are tested with carefullness and quali- fied materials have been chosen, as aluminium and tempe- rature resistant plastics for constancy at as well low temperatures as temperatures up to 90° C.