EP1252914A1

EP1252914A1 - Purified air pumping unit for protection devices with assisted ventilation

Info

Publication number: EP1252914A1
Application number: EP02076609A
Authority: EP
Inventors: Alberto Iotti
Original assignee: Kasco Srl
Current assignee: Kasco Srl
Priority date: 2001-04-24
Filing date: 2002-04-23
Publication date: 2002-10-30

Abstract

A purified air pumping unit for protection devices provided with a shell worn by the operator, said shell being connected to an air supply system provided with at least one filter unit, and comprising a manually operated pumping unit arranged to feed purified air into the interior of the protection device.

Description

This invention relates in a totally general manner to operations requiring human intervention in the presence of dangerous contaminants such as aerosols, fumes, gases, mists and dusts, for example during reclamation work involving the dismantling and salvaging of roofing and constructions comprising asbestos cement elements, the noxiousness of which is well known.
More particularly, the invention relates to a respiration device to be used in such situations.
For this purpose protection devices worn by the operator are known, they being fed with purified air.
Said devices can be flexible helmets usually known as hoods, rigid helmets or masks, with suitable feed means feeding the purified air after filtration.
The known helmets basically comprise a head covering shell; a collar of flexible material impermeable to dangerous contaminants which is sealed to the lower mouth of the shell; and a small motorized fan, usually carried by the user by means of a belt, its casing being connected on its entry side to the outside air via at least one port intercepted by a filter unit, and on its exit side to said shell via at least one hose.
The fan motor is energized by a storage or other battery carried by said belt; the fan maintains the shell under slight positive pressure to prevent contaminated air from entering it, the excess air discharging from the base of the collar, and also possibly via at least one bleed valve provided either on the shell or on the collar, or via a sized hole provided in the visor.
Other helmets, known as integral or compact, are also known in which the motorized fan and the respective powering battery are housed in a suitable compartment in the head-covering shell.
A problem arising with such helmets is the fact that the system for supplying filtered air to the shell can undergo damage or malfunction, so that the positive purified air pressure ceases within the shell, and the helmet no longer performs its proper protective function.
A second known type of protection device is represented by masks, which can be divided into:

masks operating at negative pressure,
masks of mixed operation, i.e. operating either at positive pressure or at negative pressure, where the pressurized air is served by a fixed or distal supply system,
positive pressure masks where the air is served by a movable supply system carried by the operator

The known masks comprise essentially an at least partly transparent face-covering shell, an adjustable system for fixing said shell to the operator's head, and a pressurized purified air feed conduit which usually opens at the base of said shell.
In masks with a fixed or distal supply system, said conduit comprises a hose which at one end is intended to be connected to a pressurized air source, such as a compressor unit, and in an intermediate position is intercepted by an air pressure and flow regulator apparatus, said apparatus being usually carried by the operator, while at its opposite end it is connected to the face-covering shell.
The said shell is also provided with an inhalation port which opens directly to the outside by way of a filter. The delivery end of said hose is normally connected to said port at a point located downstream of said filter.
The aforesaid masks have proved unsatisfactory for the following reasons. Firstly the hose connected to the compressor can inconveniently hinder the movements of the operator, and in fact limits his radius of action, which is obviously determined by the length of the hose.
If the operator is required to operate beyond said radius of action, which is often the case during the dismantling of masonry, he is compelled to disconnect the air feed conduit from the compressor, and from that moment the mask can operate under negative pressure by virtue of said port provided with a filter.
However between the perimetral edge of the shell and the moving operator's face, relatively large gaps can be created through which contaminated air can pass, drawn in by the depression created by the inhaling action of the operator, with all its deriving problems.
In masks with a movable supply system, the pressurized purified air is provided by a small motorized fan, usually carried by the operator by means of a belt and having its casing connected on its entry side to the outside air via at least one port intercepted by a filter unit, and on its exit side to said shell via at least one hose.
Compared with masks with a fixed supply system, the masks with a movable supply system present the advantage of not hindering the operator's movements, however they are not free of the risk of creating gaps between the face-covering shell and the operator's face through which contaminated air can pass from the outside to the inside when the absolute value of the depression due to the inhalation of the operator exceeds that of the positive pressure of the air forced by the fan.
The main object of the present invention is to overcome the drawbacks of the known art within the context of a simple, rational, reliable, durable, safe and economical construction.
Said objects are attained by a pumping unit to be associated with a protection device, worn by the operator, there being connected to said protection device the delivery side of an air supply system which on its suction side communicates with the outside via at least one port intercepted by a filter unit.
According to the invention, a manually operated pumping unit is associated with the protection device to provide purified air if for any reason this cannot be fed to the protection device by the said supply system.
According to a first embodiment, said pumping unit is directly connected to the protection device via a suitable purified air feed port.
As a variant of the invention, the pumping unit is positioned to intercept the circulation circuit of the circulation circuit associated with the air supply system.
All the objects of the invention are attained by the aforesaid solution.
In this respect, air is pumped directly by the user as soon as the filtered air supply system is no longer capable of performing its function.
As the pumping unit of the invention in fact constitutes an independent ventilation system in the sense that it does not depend on the operation of the air supply system, the user has only to take care to operate said pumping unit.
In addition, according to an advantageous characteristic of the invention said pumping unit, which will be described in detail hereinafter, can also be easily applied to existing helmets or masks, as will be apparent hereinafter.
The constructional characteristics and merits of the invention will be apparent from the ensuing detailed description given with reference to the accompanying figures, which illustrate some particular preferred embodiments thereof by way of non-limiting example.
Figure 1 is an exploded perspective view showing the invention applied to a first protection device.
Figure 2 is a partial view in the direction II of Figure 1.
Figure 3 is an enlarged part of the section III-III of Figure 1, the unidirectional automatic non-return valves being shown open.
Figure 4 is a view entirely similar to that of Figure 3, but with the valves closed.
Figures 5 and 6 show the invention applied to a different type of protection device.
Said figures, and in particular Figure 1, show a ventilated helmet, indicated overall by the reference numeral 1, and a purified air supply system indicated overall by 2.
The helmet comprises a shell 10 with sealed visor 11, automatic lateral bleed valves 12, and a collar 13 of flexible material impermeable to contaminants such as those stated in the introduction.
The illustrated collar 13, of known type, is removably fixed to the lower mouth of the shell 10, and is provided with a cord 14 for its tightening against the operator's neck.
The supply system 2, also of known type, comprises a belt 20 intended to be worn by the user and provided with a battery holder 21 and a ventilation unit 22 composed of a motor and fan, which is connected to said battery by the cable indicated by 23.
The fan casing presents two suction ports 220 with which respective filter cartridges 221 are associated, and a delivery port 222 with which a hose 121 is associated, to be connected to the entry port 122 of the shell 10.
Other details of the said means will not be described as they are well known to the expert of the art and are not pertinent to any characterising part of the invention.
For example the ventilation unit 22 can have a single suction port 220, or more than two.
According to the invention, with the ventilation unit 22 there is associated a manually operated pumping unit 3 to be used in case of emergency, for example if the ventilation unit 22 malfunctions, to enable the user to withdraw from the site of operation without breathing contaminated air.
In the embodiment shown in all the accompanying figures, the said pumping unit 3 comprises at least one bellows-shaped tubular element 4 which is open at one end and at its other end presents a rigid perforated diaphragm 5.
The tubular element 4 consists of a rather strong elastically deformable synthetic material, preferably reinforced with fibres.
Its open end is sealedly mounted on the body of the filter cartridge 221, and suitably fixed thereon. In the illustrated example said fixing is achieved by a clip 6, but there is nothing to prevent the use of different means.
The diaphragm 5 presents a series of circular apertures 7, four in number in the illustrated example, each of these being provided with a spoked dial 70 with a holed hub.
With said holed hub the is forcedly engaged the central stem 77 of a unidirectional automatic valve 8 positioned against the inner face of the diaphragm 5, as shown in Figures 3 and 4.
The illustrated valve 8 consists of a relatively thin discoidal element of elastically deformable material, said discoidal element having a diameter greater than that of the aperture 7, and presenting a slightly concave shape with its concavity facing said aperture, and with its peripheral edge in contact with the diaphragm 5 when the valve is at rest (see Figure 4).
Other types of unidirectional automatic valve can be used.
Finally, on the outer face of the diaphragm 5 there is a diametrical gripping strap 700 acting as a member for operating the respective bellows 4.
The operation of the described invention is evident.
The valves 8 remain closed when the helmet is not in use and the bellows 4 are compressed, the valves 8 opening when the ventilation unit 22 is in operation and the bellows are extended.
Figures 5 and 6 show the pumping or ventilation unit applied to a mask. Said figures show a ventilated mask, indicated overall by the reference numeral 101, with which there is associated a purified air supply system indicated overall by 103 in Figure 5 and 102 in Figure 6.
The mask 101 is of known type and comprises a transparent rigid shell 103 intended to cover the operator's face, and presenting a rear perimetral seal gasket 104; an adjustable sling 105 with chin-strap 106 for fixing the shell 103 to the operator's head; two automatic lateral bleed valves 107, of which only one is visible in the figures; and a purified air entry port 108. The supply system 103 (see Figure 5) is substantially similar to the supply system 2 already described. It essentially comprises a belt 20 intended to be worn by the operator and provided with a battery holder 21 and a ventilation unit 22 composed of a motor and fan, which is connected to said battery by the cable indicated by 23.
In addition, the fan casing presents two suction ports 220 with which respective filter cartridges 221 are associated, and a delivery port 222 with which a hose 121 is associated, to be connected to the entry port 108 of the shell 103.
Other details of the said means will not be described as they are well known to the expert of the art.
It should be noted that the ventilation unit 22 can have a single suction port 220, or more than two.
The supply system 102 (see Figure 6) comprises a belt 20 intended to be worn by the operator, and provided with a plate 44 carrying a regulator apparatus 444 from which an arrival hose 333 and departure hose 33 for the pressurized purified air extend.
Said apparatus 444 comprises an air pressure and flow regulator device 55 upstream, and a safety device 66 downstream.
Said safety device 66 is normally inactive, and is activated automatically if the regulator device 55 malfunctions, to perform the same function.
As shown, the regulator device 55 is provided with an entry connection stub 88 to which, by means of a quick connector 134, one end of the arrival hose 333 is connected, the other end 135 of which is intended to be connected to a usual compressor unit (not shown for simplicity) or equivalent.
At one end, the departure hose 33 is connected to the exit connection stub 99 of the safety device 66, and at its other end is connected to a lateral port 133 of a manifold 320.
This latter has an externally threaded end portion arranged to screw into the port 108 in the shell 103, its opposite end having an internally threaded portion to match the threaded stem of a filter cartridge 321.
The hose 33 can obviously open directly into the shell 103.
According to the invention, with the filter cartridge 221 (Figure 5) and respectively 321 (Figure 6) there is associated a manually operated pumping unit 3 to be used in case of necessity, for example when between the gasket 104 of the shell 103 and the operator's face inconvenient gaps occur through which contaminated air can enter, as explained in the introduction.
Said pumping unit 3 is obviously also useful in the case of malfunction of the ventilation unit 22, as it enables the operator to withdraw from the working site without breathing contaminated air.
The operation of the pumping unit applied to the mask is evident.
With the embodiment of Figure 5, the valves 8 remain closed when the mask 101 is not in use, with the bellows 4 compressed, the said valves 8 opening when the ventilation unit 22 is in operation and the bellows 4 are extended.
With the embodiment of Figure 6, the valves 8 remain closed when the mask is not in use, with the mask 101 connected to the compressor via the hose 333 and the bellows 4 compressed, the said valves 8 opening when the hose 333 is disconnected from the compressor and the air is drawn from the outside via the cartridge 321 by the effect of the operator's inhalation, and when the bellows 4 are extended.
The invention is not limited to that illustrated and described, but comprises all technical equivalents thereof, and their combinations, if implemented within the context of the following claims.
For example, a manual piston pump can be used instead of the manual bellows pump.
In addition, in both embodiments the manual bellows or piston pump can be positioned at points different from those shown.
For example it can be positioned directly on the shell 10 of the helmet 1 or on the shell 103 of the mask 101, for example at the centre of its upper part.
In that case the pump will be provided with its own filter element.
Again, with reference to Figure 5 said manual bellows or piston pump can be positioned either immediately downstream of the motorized fan, or immediately upstream thereof, i.e. upstream of the filter cartridge 221.
Finally, with reference to Figure 6 said manual bellows or piston pump can be positioned either downstream of the filter cartridge 321, or upstream or downstream of the regulator apparatus 444.

Claims

A purified air pumping unit for protection devices provided with a shell worn by the operator, said shell being connected to an air supply system provided with at least one filter unit, characterised by comprising a manually operated pumping unit (3) arranged to feed purified air into the interior of the protection device (1,101).
A pumping unit as claimed in claim 1, characterised in that said supply system (2) comprises a motorized fan (22) connected to said shell and having its suction side communicating with the outside via at least one port intercepted by a filter unit (221).
A pumping unit as claimed in claim 2, characterised in that said pumping unit is positioned on the suction side of the motorized fan.
A purified air pumping unit for protection devices as claimed in claim 2, characterised in that said pumping unit is positioned on the delivery side of the motorized fan.
A pumping unit as claimed in claim 1, characterised in that said pumping unit is positioned upstream of said filter unit.
A pumping unit as claimed in claim 1, characterised in that said manual pumping unit comprises a bellows-shaped deformable tubular element.
A pumping unit as claimed in claim 4, characterised in that said manual pumping unit comprises a piston pump.
A pumping unit as claimed in claim 1, characterised in that said manual pumping unit is carried by the shell of said protection device, with which it communicates via a purified air intake aperture.
A pumping unit as claimed in claim 8, characterised in that said manual pumping unit is provided with independent air filtering means.
A pumping unit as claimed in claim 1, characterised in that said manual pumping unit is provided with unidirectional automatic non-return valve members.
A pumping unit as claimed in claim 10, characterised in that said valve members each comprise a normally closed lip valve arranged to open in the presence of an entering air flow.
A pumping unit as claimed in claim 10, characterised in that said valve members each comprise a disc valve.
A pumping unit as claimed in claim 10, characterised in that said valve members each comprise a ball valve.