Gas And Heat Protective Garment

Abstract

A gas and heat protective garment comprises a suit provided with pipes for circulation of a cooling medium and a knapsack housing a respiration protecting system and a refrigerating unit including among other components a pneumatic pump and a reservoir with a liquid refrigerant. There is a gas cushion in the refrigerant reservoir, which gas cushion is put in communication with the pneumatic pump through a vapour pipe a portion of which is arranged to extend above the level of the liquid refrigerant in the reservoir and is movably mounted in said reservoir, being adapted to remain in a vertical position when the reservoir changes its attitude. Owing to this constructional arrangement the vapour pipe always extends above the level of the liquid refrigerant when the wearer of the garment inclines, whereby only refrigerant vapour is permitted to pass into the pneumatic pump. This improves the operating dependability of the garment refrigerating unit and increases the range of garment use.

Description

The present invention relates to man individual protective means and, or particularly, to gas and heat protective garments.

The invention provides protection in irrespirable atmospheres at ambient temperatures up to 150.degree. and can be used with advantage for rescue and recovery jobs in metallurgical, chemical and mining industries, as well as for fighting fire in mines.

Known is a gas and heat protective garment whose heat insulating cover accommodates a suit provided with pipes for circulation of a cooling medium and a knapsack housing a respiration protecting system and a refrigerating unit comprising a reservoir with a liquid refrigerant and a heat exchanger to abstract heat from the cooling medium circulating through the suit pipes, the circulation of said cooling medium being caused by a pneumatic pump actuated by refrigerant vapour coming from a gas cushion in the reservoir via a pipeline incorporating a pressure regulator.

The suit under consideration also has gloves, socks and a helmet arranged to leave the wearer's face open. The heat insulating cover is worn over the suit and has a window at the wearer's face.

In such a garment the refrigerant is liquid ammonia and the cooling medium is water.

The respiration protecting system of the garment under consideration is arranged in the form of a self-contained oxygen breathing apparatus comprising a breathing bag connected by means of hoses with an oxygen bottle, a regenerating cartridge and a mask. The hoses which connect the mask with the breathing bag and the regenerating cartridge incorporate inhalation and exhalation valves.

The heat exchanger incorporated in the refrigerating unit of the protective garment under consideration is constructed in the form of a pipe located on the surface of the refrigerant reservoir. Part of the heat exchanger is located inside the breathing bag for the purpose of cooling the regenerated air being inhaled.

The pneumatic pump included in the refrigerating unit has a housing which accommodates a bellows with a spring located therein. The interior of the bellows communicates with the suit pipes and the heat exchanger through hoses which are each provided with a valve arranged to open and close alternately in accordance with the bellows movement during the suction and discharge of the cooling medium. The bellows has a bottom plate against which said spring fits. Attached to the outside of the bellow bottom plate is a rod connected to a linkage adapted to operate a valve fitted in the pump housing, said valve periodically putting the pump interior in communication with the atmosphere. The pump interior communicates through a pressure regualtor with a gas cushion formed in the reservoir by refrigerant vapour. Said pressure regulator is constructed in the form of a shut-off valve accommodated in a housing and loaded by a spring the tension of which is set by the use of an adjusting screw. The adjustment of the spring governs the force holding the shut-off valve against its seat and, consequently, the actuating pressure of the refrigerant vapour.

While the garment under consideration is being worn, the pressure of the refrigerant vapour in the reservoir changes under the influence of the ambient temperature and also due to the fact that the shut-off valve of the pressure regulator is acted upon by the reservoir vapour pressure on one side and by the pneumatic pump interior pressure on the other side, said pump interior pressure periodically altering during the operation of the pump. Inasmuch as the pressure regulator spring is set to a certain reservoir vapour pressure, the pressure regulator comes into action only when a certain pressure differential acts upon the shut-off valve. This constitutes one of the disadvantages of said pressure regulator. Moreover, the shut-off valve effective area acted upon by the refrigerant vapour pressure is comparatively small and, therefore, it is difficult to effect smooth adjustment of the pressure regulator. This disadvantage eventually results in a change of refrigerant vapour pressure in the reservoir with a consequent change of refrigerant evaporation point end the temperature of the cooling medium.

In the protective garment under consideration the construction of the pneumatic pump suffers from a number of disadvantages.

One of the disadvantages is that said pump linkage is subject to shock loads during operation and is, therefore, prone to wear cut rapidly, adversely affecting the life and dependability of the pump.

A further disadvantage is that the output of the pneumatic pump depends on the pressure of the refrigerant vapour in the reservoir. When the vapour pressure drops, the rate of evaporation increases and the pump operates at a faster rate, its output increasing. When the pressure of refrigerant vapour in the reservoir rises, the reverse takes place. Since the pump output is not constant, the temperature of the cooling medium cannot be regulated smoothly. Furthermore, during suction and discharge the pressure of the cooling medium in the suit pipes varies periodically.

The protective garment under consideration suffers from the disadvantage that the pipeline connecting the gas cushion in the reservoir to the pneumatic pump is fixedly mounted in the reservoir. When the wearer inclines, the liquid refrigerant gets into said pipeline, passes into the pressure regulator and thence into the pneumatic pump, wherefrom it is exhausted into the atmosphere. The resultant waste of the refrigerant shortens the useful working time of the garment. Besides, the liquid refrigerant (ammonia) evaporates on getting into the pneumatic pump portion communicating with the atmosphere. Since the evaporation of the refrigerant is accompanied by intensive absorption of heat, the temperature inside the pneumatic pump drops down to -34.degree. C (the boiling point of liquid ammonia at atmospheric pressure). At this temperature the cooling medium contained in the bellows freezes and the protective garment ceases functioning.

It is an object of the present invention to increase the scope and improve the dependability of the gas and heat protective garment.

This and other objects are achieved by providing a gas and heat protective garment whose heat insulating cover accommodates a suit provided with pipes for circulation of a cooling medium, a knapsack housing a respiration protecting system, and a refrigerating unit comprising a reservoir with a liquid refrigerant and a heat exchanger to abstract heat from the cooling medium circulating through the suit pipes, the circulation of said cooling medium being caused by a pneumatic pump actuated by refrigerant vapour coming from a gas cushion in the reservoir via a pipeline incorporating a pressure regulator.

According to the invention, said pipeline is provided with a vapour pipe a portion of which extends above the level of the liquid refrigerant and is movably mounted in the reservoir so that it remains in a vertical position when the refrigerant reservoir changes its attitude. This arrangement permits only refrigerant vapour to pass to the pneumatic pump.

It is desirable that said vapour pipe be connected to said pipeline by means of a flexible hose and be mounted substantially in the middle of the refrigerant reservoir, said vapour pipe being pivoted at this location and adapted to make a pivotal movement by the action of a counterweight mounted opposite thereto.

Owing to this construction, the wearer of the protective garment which constitutes the present invention can incline and make other movements, there being no possibility for the liquid refrigerant to get into the vapour pipe. Further, this construction increases the range of garment use.

In one of the embodiments of the invention the vapour pipe is mounted in the refrigerant reservoir by means of a ball and socket joint.

It is desirable that the pressure regulator incorporated in the pipeline connecting the pneumatic pump with the gas cushion in the refrigerant reservoir be provided with a spring-loaded flexible element adapted to be acted upon by refrigerant vapour pressure, said flexible element being located in the pressure regulator housing and mounting a valve adapted for closing said pipeline.

The pressure regulator constructed according to this invention is more sensitive than that known in the prior art and can be adjusted while the garment is being worn. It can be used advantageously under the conditions precluding the entry of liquid ammonia therein.

In another embodiment of the invention a refrigerant vapour pressure stabilizer is incorporated in said pipeline between the pressure regulator and the pneumatic pump in order that the refrigerant vapour pressure be maintained constant irrespective of variation of the vapour pressure in the refrigerant reservoir.

In still another embodiment of the invention the pneumatic pump comprises a pneumatic pulse generator piped to the vapour pressure stabilizer and also comprises two spring-loaded diaphragms housed in individual cases. Each diaphragm divides its case into two separate chambers one of which communicates with the pneumatic pulse generator and the other with the pipeline connecting the suit pipes with the heat exchanger.

This constructional arrangement of the pneumatic pump stabilizes its output and improves the operating dependability of the refrigerating unit.

It is desirbale that the pneumatic pulses generator be constructed in the form of a four-membrane pneumatic relay with two groups of pneumatic contacts. This constructional arrangement reduces the size and weight of the pneumatic pump carried in the knapsack and improves its operating dependability.

The gas and heat protective garment which constitutes the present invention enables the wearer to perform various physical activities, there being no possibility for liquid refrigerant to get into the pressure regulator and the pneumatic pump. This feature improves the operating dependability of the protective garment.

Now the invention will be described in detail with reference to the accompanying drawing in which:

FIG. 1 shows a general view of the gas and heat protective garment according to the invention.

FIG. 2 is a diagrammatic view of the cooling system.

FIG. 3 is an enlarged view of the detail III of FIG. 1.

FIG. 4 is an enlarged view of the detail IV of FIG. 1.

FIG. 5 shows the attitude of the refrigerant reservoir and the vapour pipe therein, with the wearer inclined forward.

FIG. 6 shows same, with the wearer inclined backward.

The gas and heat protective garment is designed for emergency work in mines at temperatures up to 150.degree., in an atmosphere having no oxygen or containing noxious gases such as carbon oxide, hydrogen sulphide, sulphur dioxide and nitric oxide.

The garment comprises elastic fabric suit 1 (FIG. 1) made integral with a helmet, gloves (not shown) and socks (not shown). Mounted ont the suit outside are pipes 2 for circulation of the cooling medium. The pipes are made of elastic material, for example, polyvinyl chloride. The total length of the pipes and their inside and outside diameters are chosen so as to provide for dissipating excessive heat from the wearer's body and maintain the temperature of the wearer's body within permissible limits. The pipes 2 are harnessed to a manifold 3 constructed in the form of a circular tube. The manifold 3 is mounted on the helemet of the suit 1. The interior of the manifold 3 is divided by means of partitions into two parts, viz. an inlet section and an outlet section. The ends of the pipes 2 are connected one to each section of the manifold 3.

Adjoining the suit 1 is a knapsack 4 accommodating a respiration protecting system and a refrigerating unit. The knapsack 4 has a rigid thin-walled case 5 with a lid (not shown). Attached to the knapsack case side nearest the wearer's back are shoulder straps 6 and a belt (not shown).

The respiration protecting system is located in the upper (as shown) part of the knapsack 4. This system is essentially a self-contained oxygen breathing apparatus 7. It comprises a regenerating cartridge 8 filled with a carbon dioxide absorbent, for example, calcium carbonate CaCO.sub.3. The regenerating cartridge 8 has a connecting piece 9 joined to a breathing bag 10 which is made of a gas-tight elastic material and has a capacity sufficient for normal breathing in performing physical activities.

The breathing bag 10 is provided with a valve 11 the purpose of which is to release excess air when the air pressure exceeds the permissible limit and to prevent accumulation of nitrogen in the bag.

The breathing apparatus 7 also comprises an oxygen bottle 12 having a shut-off valve 13 connected to an oxygen feed device 14. Said oxygen feed device comprises a pressure gauge (not shown), and a pressure reducer 15 with associated automatic and manual oxygen feed control mechanisms. These mechanisms are housed in the same case to the pressure reducer 15 and are connected to the breathing bag 10 by means of a connecting piece 16.

A connecting piece 17 provided on the top (as shown) part of the regenerating cartridge 8 receives a breathing hose 18 which incorporates an inhalation valve 19. A connecting piece 20 provided on the bottom (as shown) part of the regenerating cartridge 8 receives a hose 21 which incorporates an exhalation valve 22. Some distance from the regenerating cartridge 8 the hoses 18 and 21 are connected to a hose 23 which in turn, is connected to a mask 24.

Mounted on the connecting piece 9 inside the breathing bag 10 is a cooler 25 for the air being inhaled. The air cooler 25 has a case 26 which houses a tubular heat exchanger 27. The heat exchanger 27 is connected to the manifold 3 by means of a flexible hose 28 and is also connected to a refrigerating unit 29 located in the lower part of the knapsack 4. The refrigerating unit 29, cooler 25, pipes 2, manifold 3 and connecting lines form the cooling system of the protective garment.

The refrigerating unit 29 comprises a reservoir 30 containing liquid refrigerant to abstract heat from the cooling medium circulating in the pipes 2 of the suit 1. The reservoir 30 is connected by means of a pipeline 31 to a pneumatic pump 32 which delivers the cooling medium to the manifold 3 and the pipes 2 through a heat exchanger 33 built into the reservoir 30. The refrigerant is liquid ammonia, the cooling medium is water. The reservoir 30 constantly contains a gas cushion formed by refrigerant vapour.

The reservoir 30 (FIG. 2) is constructed in the form of a cylinder with dished end plates. It is mounted in the case 5 (FIG. 1) of the knapsack 4 and is adapted to be removed for charging with refrigerant. A charging connection 34 (FIG. 2) is provided in one of the reservoir end plates.

A valve 35 is fitted in the right (as shown) end plate of reservoir 30. The valve 35 has a body 36 (FIG. 3) fitted into a union 37 which is welded to the reservoir end plate. The valve body 36 is held to the union 37 by a nut 38, the joint between the two being made tight by means of a sealing ring 39.

The pipeline 31 which connects the refrigerant reservoir 30 with the pneumatic pump 32 is fitted to the valve 35 and incorporates a refrigerant vapour pressure regulator 40 (FIG. 2).

Mounted inside the refrigerant reservoir 30 is a vapour pipe 41 the purpose of which is to supply refrigerant vapour to the pneumatic pump 32. One end of the vapour pipe 41 extends above the level of the refrigerant in the reservoir 30. The intermediate portion of the vapour pipe 41 is made in the form of a flexible hose 42 (FIG. 3). The vapour pipe 41 is pivotally mounted in the middle of the reservoir 30 and is provided with a counterweight 43 mounted in line with the extending portion of the vapour pipe 41 and opposite thereto in relation to the pivot point.

The vapour pipe 41 is mounted in the refrigerant reservoir 30 by means of a ball joint 44 comprising a spherical socket 45 to the lower (as shown) portion of which is fixedly mounted the counterweight 43, the extending portion of the vapour pipe 41 being mounted on the socket 45 diametrically opposite to the counterweight 43.

The end of the vapour pipe 41 mounted on the socket 45 has a connecting piece 46 to receive one end of the hose 42. The other end of the hose 42 is fitted to a connecting piece 47 welded to the portion of the vapour pipe 41 which is fitted to the body 36 of the valve 35. The free end of this portion of the vapour pipe 41 is closed with a plug 48 made integral with a screw 49 the purpose of which is to mount the ball joint 44.

The length of the hose 42 is chosen so that the portion of the vapour pipe 41 extending above the refrigerant level can pivot about the ball joint 44 through an angle of at least 180.degree. in any plane in response to alteration of the attitude of the refrigerant reservoir 30 occurring when the wearer inclines.

The hose 42 is to be made of an elastic material proof against the effects of liquid ammonia and offering the minimum possible resistance to the pivoting action of the counterweight 43, these properties lasting throughout the service life of the protecting garment.

Refrigerant vapour passes to the pneumatic pump 32 through the pipe 41, the valve 35 and the pipeline 31 in which is incorporated the pressure regulator 40 (FIG. 2).

A pressure regulator of the construction known in the prior art may be used, but it is more advantageous to employ the pressure regulator described herein.

The pressure regulator 40 has a housing 50 (FIG. 4) with a threaded cover 51. The joint between the housing and cover is made tight by means of a sealing ring 52. The housing 50 accommodates a bellows 53 which is a flexible element actuated by the pressure of the refrigerant vapour. The end of the bellows 53 facing toward the cover 51 is closed with a cover 54 which prevents the refrigerant vapour from entering the bellows. Mounted on the cover 54 is a valve 55 adapted to close the pipeline 31 which connects the housing 50 of the pressure regulator 40 with the pneumatic pump 32 (FIG. 1). The pipeline 31 is connected to the pressure regulator cover 51 which is provided with a passage 56 for the refrigerant vapour to enter the housing 50. The cover 51 has a central hole 57 into which is fitted a seat 58 for the valve 55. The central hole 57 leads into a passage 59 provided for the refrigerant vapour to pass from the pressure regulator housing 50 into the pipeline 31. A recess 60 is provided in the cover 51 in line with the hole 57 for the purpose of guiding the valve 55.

Located inside the bellows 53 and coaxially therewith is a spring 61 bearing against a spring seat 62 which is recessed centrally to receive the end of an adjusting screw 63. The adjusting screw 63 is threaded into a nut 64 which serves the purpose of setting the tension of the pressure regulator spring 61 to the low limit of the refrigerant vapour pressure.

The nut 64 also has an external thread to screw into a cover 65 which is fitted onto the pressure regulator housing 50 and closes the bellows 53. The bellows end facing the nut 64 is secured in the pressure regulator housing 50. Upon adjusting the tension of the spring 61, the nut 64 is fixed in position relatively to the cover 65 by means of a locknut 66. To enable the wearer to adjust the tension of the spring 61, the adjusting screw 63 is connected to a flexible shaft 67 arranged to extend beyond the knapsack case 5 and provided with a knob at the end.

For the pressure of the refrigerant vapour entering the pneumatic pump 32 to be maintained constant irrespective of the vapour pressure in the refrigerant reservoir 30, a pressure stabilizer 68 is interposed in the pipeline 31 between the pressure regulator 40 and the pneumatic pump 32. The constructional arrangement of the pressure stabilizer 68 is similar to that of the pressure regulator 40, except that the spring seat 62 (FIG. 4) in the pressure stabilizer bears direct against the nut 64, there being no adjusting screw 63 and flexible shaft 67. Also the cover 51 is provided with a passage (not shown) to which is connected a pipeline 69 through which the refrigerant vapour is exhausted into the atmosphere for reducing the vapour pressure to the point required for the operation of the pneumatic pump 32.

In the gas and heat protection garment which constitutes the present invention a pneumatic pump of the construction known in the prior art may be used. However, owing to the provision of the vapour pipe 41 arranged to prevent liquid refrigerant from entering the pump, it is more advantageous to employ a pump constructed as described hereinafter since it gives a steady flow of the cooling medium through the pipes 2 of the suit 1.

The pneumatic pump 32 (FIG. 1) comprises a pneumatic relay 70 (FIG. 2) the purpose of which is to generate pneumatic pulses. The pneumatic relay 70 has a case 71 which houses a membrane assembly 72 composed of membranes 74, 75, 76 and 77 which are spaced apart and fixedly secured on a rod 73. The membranes and the case 71 form chambers A, B and C. The rod 73 is hollow and has seats 78 provided in its ends. Two partitions 79, located one at each side of the membrane assembly 72 inside the case 71 of the pneumatic relay 70, are fixedly secured parallel to the membranes. Each partition 79 has a central hole 80 formed coaxially with the rod 73 and accommodating a seat 81.

Two valve plates 82 are mounted square with the rod 73, one at each end thereof. Each valve plate 82 is loaded by a spring 83 fitted between the valve plate and the respective end wall of the case 71. The diameter of the valve plates 82 is slightly larger than the diameter of the seats 81. Each valve plate 82 and is associated seats 81 and 79 form a group of pneumatic contacts.

The partitions 79, case 71 and end membranes 74 and 77 form chambers D, E, G and H. The membranes 74, 75, 76 and 77 have different effective areas (the areas acted upon by the pressure of the working medium in the respective chamber of the pneumatic relay 70). The effective areas of the membranes and the relationship therebetween are chosen according to the diameters of the seats 78 and 81 and the pressure of the working medium in each of the chambers of the pneumatic relay 70. The effective areas of the membranes 74 and 77 are equal. The effective area of the membrane 75 is approximately 1.5 times that of the membrane 74 or 77. The effective area of the membrane 76 is 2.5 times that of the membrane 75.

The interior of therod 73 communicates with the chamber A by means of a hole provided in the rod 73 between the membranes 74 and 75. The chamber A is connected to the pressure stabilizer 68 by means of the pipeline 31.

The pneumatic pump 32 (FIG. 1) also comprises two cases 84 (FIG. 2) housing elastic diaphragms 85. The edge of each diaphragm 85 is secured all the way around in the case 84. The left (as shown) case 84 is divided by the diaphragm into two separate chambers K and L. The right (as shown) case 84 is divided by the diaphragm into two separate chambers M and N. The chambers K and N are connected by means of pipelines 86 and 87 respectively with the chambers E and G of the pneumatic relay 70. The pipeline 86 is connected through a pipeline 88 to the chamber C. The pipeline 87 is connected through a pipeline 89 to the chamber B. Each of the pipelines 88 and 89 incorporates a valve 90. The chambers D and H of the pneumatic relay 70 communicate with the atmosphere through pipelines 91 and 92 in order to let out the vapour exhausted from the pneumatic pump 32. The aforementioned pipeline 69 is connected to the pipeline 91.

The upper (as shown) part of each case 84 is provided with a connecting piece 93 positioned square with the diaphragm 85. Located in each case 84 coaxially with the connecting piece 93 is a spring 94 one end of which bears against the diaphragm 85 and the other end bears against circular projection (not shown) provided inside the connecting piece 93.

The connecting pieces 93 are joined to a pipeline 95 which incorporates delivery valves 96, one for each diaphragm 85. The connecting pieces 93 are also joined to a flexible pipeline 97 which connects to the manifold 3 of the suit 1. Some distance from the connecting pieces 93 the pipeline 97 divides into branches supplying the cooling medium, which circulates in the pipes 2 of the suit 1, to the chambers L and M of the pneumatic pump 32. Each branch of the pipeline 97 incorporates a suction valve 98. A pipe 99 fitted to the pipeline 95 between the valves 96 connects the pipeline 95 to the heat exchanger 33 located in the refrigerant reservoir 30. The heat exchanger 33 is connected through a hose 100 to the aforementioned heat exchanger 27 of the respiration protecting system.

For convenience in use, the flexible hose 28, which connects the manifold 3 of the suit 1 with the heat exchanger 27, and the pipeline 97, which connects the mainfold 3 with the pneumatic pump 32, are provided with hermetically sealed connection members (not shown) which enable the suit, respiration protecting system and refrigerating unit to be kept filled with the cooling medium during storage.

The suit 1 and the knapsack 4 are completely enclosed with a three-layer heat insulating cover 101 (FIG. 1). This cover includes an outer layer 102 of a heat-resistant fabric with a metallized coating, an inner layer 103 of a rubberized fabric and layer 104 of soft polyurethane foam sandwiched between said layers 102 and 103. At the wearer's face the cover 101 has a window 105 made of heat resisting and rejecting glass.

The initial state of the components of the protective garment before putting it on is as follows:

The regenerating cartridge 8 is filled up with carbon dioxide absorbent. The bottle 12 is charged with oxygen and the bottle valve 13 is shut off.

The reservoir 30 is filled up with liquid refrigerant. The reservoir valve 35 is shut off. The pipes 2, manifold 3, hose 28, heat exchangers 27 and 33, chambers L and M, connecting pieces 93, pipeline 95 and flexible pipeline 97 are filled up with coolant.

The pressure regulator 40 is adjusted preliminarily. For the purpose the adjusting screw 63 is turned all the way out. The nut 64 is fixed by means of the locknut 66 in the position where the valve 55 can open only when the refrigerant vapour pressure acting on the bellows 53 is at least 4.5 kg/cm.sup.2, inasmuch as at a lower vapour pressure the boiling point of liquid ammonia approaches 0.degree. C, under which conditions the water contained in the heat exchanger 33 is likely to freeze. When adjusting the pressure regulator finally before the beginning of the operation, the adjusting screw 63 is to be turned all the way in.

The pressure stabilizer 68 is set to the vapour pressure required for the operation of the pneumatic pump 32. The surplus refrigerant vapour is exhausted through the pipeline 69 into the atmosphere.

The diaphragms 85 of the pneumatic pump 32 are in the lowermost (as shown) position, each being held by the spring 94 against the case 84.

After the wearer has been dressed in the suit 1 complete with the knapsack 4, a checkover is made on the performance of the respiration protecting system. For the purpose the mask 24 is put on and the valve 13 of the bottle 12 is turned on for the oxygen to pass from the bottle 12 through the feed device 14 into the breathing bag 10. The exhaled air passes through the hoses 23 and 21 into the regenerating cartridge 8 where carbon dioxide is absorbed. Therefrom the purified air passes through the connecting piece 9 into the breathing bag 10, coming in contact with the heat exchanger 27 of the cooler 25. In the breathing bag 10 the air mixes with oxygen and on inhalation, again coming in contact with the heat exchanger 27, passes through the hose 18, valve 19, hose 23 and mask 24 to be breathed in.

During the breathing the oxygen feed device 14 automatically feeds the required quantity of oxygen into the breathing bag 10.

If there is an excess of the air in the breathing bag 10, valve 11 opens automatically and part of the air is exhausted into the atmosphere, whereby accumulation of nitrogen is prevented.

After checking the respiration protecting system, the cooling system is checked up. For the purpose the valve 35 of the refrigerant reservoir 30 is turned on, permitting the refrigerant vapour to pass through the vapour pipe 41, the connecting piece 46, the hose 42 and the other portion of the vapour pipe 41 into the body 36 of the valve 35 and thence via the pipeline 31 into the housing 50 of the pressure regulator 40.

As the refrigerant vapour comes into the housing 50, the vapour pressure therein rises. At the same time the adjusting screw 63 is manipulated by means of the knob attached to the flexible shaft 67, said screw 63 being turned out until the load of the spring 61 holding the valve 55 against its seat 58 is overcome by the refrigerant vapour pressure exerted on the bellows 53. With these conditions obtained, the valve 55 becomes unseated stabilizer therefrigerant vapour passes by way of the hole 57 provided in the seat 58 into the passage 59 and thence via the pipeline 31 into the pressure stabilizer 68.

The pressure stabiliser 68 has been set to the refrigerant vapour pressure required for the operation of the pneumatic pump 32. As a rule, this pressure is considerably lower than the vapour pressure in the refrigerant reservoir 30. Therefore, when the pressure of the refrigerant vapour in the stabilizer 68 rises, it compresses the bellows against the load of the spring, unseating the valve and thereby permitting the vapour to be vented tinto the atmosphere through the pipeline 69. The exhaust continues until the vapour pressure drops to the stabilizer setting. Practically, the vapour exhaust is constant. From the pressure stabilizer 68 the refrigerant vapour passes by way of the pipeline 31 into the chamber A of the pneumatic relay 70 and into the interior of the rod 73. Since the effective area of the membrane 75 is larger than that of the membrane 74, the former is acted upon by a greater vapour pressure and is caused to deflect to the right (as shown), moving the rod 73 in the same direction. The rod 73 leaves the left (as shown) valve plate 82, whereby the chamber E is put in communication with the rod interior. The rod 73 comes up against the right valve plate 82 and, moving further against the load of the spring 83, shifts the valve plate 82 to the right and off the seat 81, thereby putting the chamber G in communication with the chamber H and, consequently, with the atmosphere.

From the chamber E the refrigerant vapour passes through the pipeline 86 into the chamber K in the left diaphragm case 84. The pressure of the refrigerant vapour causes the diaphragm 85 to move upward (as shown) against the load of the spring 94, forcing out the cooling medium from the chamber L through the delivery valve 96 into the pipeline 85. Therefrom the cooling medium passes via the pipe 99 into the heat exchanger 33 where it cools off. Thence the cooling medium passes via the pipeline 100 into the heat exchanger 27 located in the breathing bag 10 and from there flows through the hose 28 into the manifold 3 and thence into the pipes 2 of the suit 1.

While passing into the chamber K of the diaphragm case 84, the refrigerant vapour also passes through the pipeline 88 and the valve 90 into the chamber C of the pneumatic relay 70 (the valve 90 is set to allow the refrigerant vapour to flow at a rate much lower than the rate of flow through the pipeline 86). Since the effective area of the membrane 76 is larger than the sum of the effective areas of the membranes 77 and 75, the pressure of the refrigerant vapour causes the membrane 76 to move to the left (as shown), bringing the rod 73 against the left valve plate 82. Moving further against the load of the spring 83, the rod 73 shifts the valve plate 82 to the left and off its seat 82, thereby putting the chamber E in communication with the chamber D. Consequently, the chamber K communicates with the atmosphere through the pipelines 86 and 91 and the chamber C communicates with the atmosphere through the pipelines 88, 86 and 91. When moving to the left, the rod 73 leaves the right valve plate 82 and the latter, under the action of the spring 83, closes the seat 81. As a result, the chamber G is isolated from the chamber H and, consequently, from the atmosphere, whereas the interior of the rod 73 is put in communication with the chamber G. The refrigerant vapour passes via the pipeline 83 and the interior passage in the rod 73 into the chamber N, at the same time passing via the pipeline 89 and the valve 90 into the chamber B of the pneumatic relay 70. The pressure of the refrigerant vapour causes the diaphragm 85 to move upward (as shown) against the load of the spring 94, forcing out the cooling medium through the delivery valve 96 into the pipeline 95, wherefrom it passes through the pipe 99 into the heat exchanger 33.

This condition continues until the vapour pressure exerted on the membrane 76 overcomes the vapour pressure exerted on this membrane from the chamber G, which is open to the atmosphere during this period.

As the vapour pressure in the chambers K, E and C drops, the left (as shown) diaphragm returns into the initial position under the action of the spring 94, drawing in the cooling medium from the suit pipes 2, the cooling medium coming via the manifold 3, the pipeline 97 and the valve 98. Thus, the suction stroke of the left diaphragm 85 occurs simultaneously with the delivery stroke of the right diaphragm 85.

When the pressures exerted on the membrane 76 from the chambers B and C have become equal, the rod 73 is moved to the right due to the vapour pressure acting on the membrane 75, since the refrigerant vapour enters the chamber A constantly. The operating cycle of the pneumatic pump 32 is repeated, i.e., during the discharge stroke of the left diaphragm 85 the right diaphragm 85 makes a suction stroke. Inasmuch as the diaphragms 85 move in anti-phase and the pressure of the refrigerant vapour entering the chamber A of the pneumatic relay 70 is constant the cooling medium moves in a steady flow throughout the cooling system irrespective of variation of the vapour pressure in the refrigerant reservoir 30 during the wearer's activities.

After the checks on the breathing and cooling systems have been completed, the heat insulating cover 101 is put over the suit 1 and the knapsack 4.

During the wearer's activities the breathing and cooling systems operate as described hereinbefore. Owing to the wearer's movements, the knapsack and, consequently, the refrigerant reservoir 30 change their attitude, the surface of the liquid refrigerant contained in the reservoir 30 remaining horizontal. The portion of the vapour pipe 41 connected to the valve 35 follows the movement of the refrigerant reservoir 30, the other portion of said vapour pipe 41, which extends above the level of the refrigerant and is mounted on the socket 45 of the ball joint 44 attached to the free end of the first-mentioned portion of the vapour pipe 41, being kept vertical by the action of the counterweight 43 attached to the opposite side of said socket 45, the provision of the flexible hose 42 enabling the extending portion of said vapour pipe 41 to pivot about the ball joint 44. Referring to FIGS. 5 and 6, said portion of the vapour pipe 41 is always kept vertical, extending above the level of the liquid refrigerant irrespective of the attitude of the refrigerant reservoir 30. Thereby the liquid refrigerant is prevented from getting into the vapour pipe 41 to preclude its waste, improve the operating dependability of the pneumatic pump 32 and increase the range of use of the protective garment which constitutes the present invention.

Claims

What is claimed is:

1. A gas and heat protective garment comprising: a heat insulating cover; a suit provided with pipes for circulation of a cooling medium; a knapsack accommodating a respiration protecting system and a refrigerating unit, said suit and said knapsack being enclosed with said heat insulating cover; said refrigerating unit comprising: a reservoir with a liquid refrigerant contained therein and a heat exchanger, said reservoir and heat exchanger serving the purpose of abstracting heat from said cooling medium circulating in said pipes of said suit, a pneumatic pump actuated by refrigerant vapour, a pipeline connecting said pneumatic pump with a gas cushion in said refrigerant reservoir, a pressure regulator incorporated in said pipeline, a vapour pipe forming a part of said pipeline, a portion of said vapour pipe being arranged to extend above the level of the liquid refrigerant contained in said reservoir, said extending portion of the vapour pipe being movably mounted in the refrigerant reservoir and adapted to remain in a vertical position when said refrigerant reservoir changes its attitude, this constructional arrangement permitting only refrigerant vapour to pass to said pneumatic pump.

2. A gas and heat protective garment as claimed in claim 1 in which said vapour pipe is connected to said pipeline by means of a flexible hose and is mounted substantially in the middle of said refrigerant reservoir, said vapour pipe being pivoted at this location and adapted to make a pivotal movement by the action of a counterweight mounted opposite thereto.

3. A gas and heat protective garment as claimed in claim 2, in which said vapour pipe is mounted in said refrigerant reservoir by means of a ball and socket joint.

4. A gas and heat protective garment as claimed in claim 1, in which said pressure regulator is provided with a spring-loaded flexible element adapted to be acted upon by refrigerant vapour pressure, said flexible element being located in the pressure regulator housing and mounting a valve adapted for closing said pipeline connecting the pneumatic pump with the gas cushion in the refrigerant reservoir.

5. A gas and heat protective garment as claimed in claim 4, in which a pressure stabilizer is incorporated in said pipeline between the pressure regulator and the pneumatic pump in order that the pressure of the refrigerant vapour entering the pneumatic pump be maintained constant irrespective of variation of the vapour pressure in the refrigerant reservoir.

6. A gas and heat protective garment as claimed in claim 5, in which said pneumatic pump comprises a pneumatic pulse generator piped to said pressure stabilizer and includes two spring-loaded diaphragms housed in individual cases, each diaphragm dividing its case into two separate chambers one of which communicates with the pneumatic pulse generator and the other with the pipeline connecting the suit pipes with the heat exchanger.

7. A gas and heat protective garment as claimed in claim 6, in which said pneumatic pulse generator is constructed in the form of a four-membrane pneumatic relay with two groups of pneumatic contacts.