WO2002093061A1

WO2002093061A1 - Rapid coupling for automatic verification of the proper connection between dispenser and mask of a compressed air self-contained breathing apparatus

Info

Publication number: WO2002093061A1
Application number: PCT/IT2002/000208
Authority: WO
Inventors: Romano Moscatelli; Maurizio Rettaroli
Original assignee: Dispositivi Protezione Individuale D.P.I. S.R.L.; Interspiro Ab
Priority date: 2001-05-11
Filing date: 2002-04-03
Publication date: 2002-11-21
Also published as: AU2002258149A1; WO2002093061A8; AU2002258149A8; ITRM20010248A0; ITRM20010248A1

Abstract

Rapid coupling with automatic verification of the correct connection between dispenser and mask of a compressed air self-contained breathing apparatus for the protection of the respiratory tract, in which a hollow cylindrical portion (70) of a mask inspiration inlet (7), having a protruding end ring (71) and one or more outer longitudinal grooves (101; 102), and an associated end annular portion (80) of a dispenser (8) are held together in detachable fashion by means of one or more radially retractable blade organs (6; 6'), each having a retaining blade (64) with curved lunette free end having a predetermined circumferential width, corresponding to that of the outer longitudinal grooves into which they are received.

Description

Rapid Coupling with Automatic Verification of the Proper Connection between Dispenser and Mask of a Compressed Air S elf-Contained Breathing Apparatus

Technical Field

The present invention relates to a rapid coupling with automatic verification of the proper connection between dispenser and mask of a compressed air self-contained breathing apparatus for protecting the respiratory tract. An open loop compressed air self-contained breathing apparatus is an isolating device for protecting the respiratory tract, which acts by supplying the user with breathable air initially contained under pressure in a tank. The self-contained breathing apparatus comprises a mask that achieves the pneumatic seal on the user's face to prevent polluted outside air from entering and a dispenser, which supplies the breathable air making it available to the user for breathing at near-atmospheric pressure. The dispenser is connected, in airtight fashion, to the mask in correspondence with its inspiration inlet.

Prevalently, the mechanical coupling between the mask and the dispenser can be of the threaded type or of the snap on, rapid coupling type.

The threaded coupling has the advantage that the uncoupling between mask and dispenser occurs as a result of their mutual rotation so that, although loss of seal due to insufficient tightening is still possible, the total uncoupling between mask and dispenser is unlikely. On the other hand, the coupling operation is rather long and it requires perfect alignment between the coupling male and female parts.

Rapid couplings have become widely used by virtue of their rapidity and ease of connection, but if the operation is not performed correctly and completely, there usually is a potential for a sudden and total uncoupling of the dispenser from the mask with the instantaneous and total cessation of the protective function.

It is therefore easy to understand how desirable it is, in the case of rapid coupling connection, to have the ability to verify the correct and complete connection between dispenser and mask. Background Art

Numerous electrical and electronic devices providing this capability already exist, but they are generally complex, costly and not always wholly reliable.

The present invention instead is aimed at allowing, in a simple and safe manner, a verification of the proper connection between mask and dispenser in particular types of rapid coupling in which a retaining blade element achieves a detachable connection between parts of a mask and of a dispenser tasked with said connection.

A known coupling is shown in Figure 1, in which a mask inspiration inlet, shown partially, is indicated as 1 and a dispenser, also shown partially, is indicated as 2. The mask inlet 1 is obtained in its terminal part with a hollow cylindrical element 10 projecting anteriorly from the mask (not shown). The hollow cylindrical element 10 teπninates anteriorly with a protruding ring 11, hence with its outer diameter exceeding that of the hollow cylindrical element 10.

The dispenser 2 terminates, in its portion to be coupled to the mask, with an annular throat 20, able to receive, preferably flush, in its interior the end of the hollow cylindrical element 10 and its protruding ring 11. A sealing gasket 3 is housed in a related seat 4 of the inspiration inlet 1 of the mask for a hermetic seal between said inlet and the dispenser 2.

To make stable the coupling between mask and dispenser, at least a retractable organ is present, having a retaining blade 5 that positions itself inside the protruding ring 11. When the retractable organ is approached to the inlet 1, it prevents the extraction of the mask, and vice versa, when it is moved away, it allows the insertion and extraction of the dispenser into and from the mask. h this type of solutions it may occur that the insertion of the dispenser does not take place completely and correctly, for instance by effect of friction or due to the presence of extraneous bodies, or that the retracting body is not correctly positioned, with the consequence of the sudden detachment of the dispenser from the mask.

Disclosure of Invention

An aim of the present invention is to ascertain whether the conditions for this undesired event to take place do in fact exist. In particular, the aim of the invention is to ascertain that this undesired event cannot take place through a mode known as "fail to safe", which, in other words, means that the system may give an alarm signal even if there is no real risk of disconnection and detachment, but when there is a real risk it cannot be ignored. The invention, therefore, solves the problem of providing a rapid coupling with the automatic verification of the correct connection between dispenser and mask of a compressed air self-contained breathing apparatus for the protection of the respiratory tract, in which a mask inspiration inlet, having a hollow cylindrical portion with a protruding end ring and an associated annular end portion of a dispenser are held together in detachable fashion by means of a pair of radially retractable blade organs, each having at least a retaining blade with curved lunette free end having a predetermined circumferential width, coupling which is characterised in that said hollow cylindrical portion externally exhibits at least a pair of diametrically opposite longitudinal grooves whose width is at least equal to said predetermined circumferential width of said locking blades and whose radial depth is sufficient for said locking blades to be received in said pair of longitudinal grooves.

Description of the Drawings

Further features and advantages of the invention shall become more readily apparent from the detailed description that follows of a preferred embodiment, illustrated purely by way of non limiting example in the accompanying drawings, in which:

Figure 1 shows a longitudinal section of a connecting portion of a first known rapid coupling of a mask with a dispenser;

Figure 2 shows a perspective view of a retractable connecting organ for the rapid coupling of the mask with a dispenser, according to the invention; - Figure 3 shows a longitudinal section of a connecting portion for the rapid coupling of the mask with a dispenser;

Figures 4, 5 show schematic lateral views of a first embodiment of rapid coupling between dispenser and mask according to the invention, respectively in locked and unlocked position; and - Figure 6 shows a longitudinal section of a second embodiment of rapid coupling between dispenser and mask according to the invention in locked position.

Description of the Illustrative Embodiment

With reference to Figures 4 and 5, a first embodiment of rapid coupling according to the invention is shown schematically. Therein are indicated identical or similar parts with reference numbers that are identical or similar to those of Figure 1. In the outer peripheral surface of the hollow cylinder 100 of the inspiration inlet 1 of the mask is obtained at least one or, preferably as shown, a pair of diametrically opposite longitudinal grooves 101 to receive retaining blades 5. In Figure 4 the retaining blades 5 are in locked position relative to the longitudinal grooves 101.

The longitudinal grooves 101 are obtained in a position corresponding to that of the retaining blades, their width will be at least equal to that of the retaining blades, and their depth will be such as to receive the blades when they are inserted in spring like fashion in the sense of the arrows F, F' in centripetal direction. Figure 5 shows the unlocked position, in which the blades are moved away according to the arrows G, G' and the inspiration inlet 1 of the mask is rotated by 90? relative to the dispenser according to arrow K.

According to the invention and with reference to Figure 2, one of said retaining blades 5 is embodied by a retractable organ 6 which has an annular central portion 60 extending in two diametrically opposite "C" shaped elements 61 and 62, respectively proximal and distal, relative to the centre of the annular portion 60 towards which their concavities face. The proximal "C" shaped element 61 has in its f ee end two lunette blades 63, 63 separated by a slide projection 64. In proximity to the distal element 62 is present an opening 65, as shall be explained farther on. In the coupling shown in Figure 3, an inspiration inlet 7 of the mask includes a cylindrical portion 70 with a projecting ring 71, whilst around a dispenser portion 8 is formed an annular throat 80.

A pair of retracting organs 6, & are inserted coaxially with said "C" shaped proximal elements 61, 61', rotated by 180° and opposing each other passed, one inside the other, through the respective openings 65, 65', and loaded by springs 9, 9' positioned radially so that said organs effect a centripetal action relative to the coupling portion comprising the projecting ring 71 and the annular throat 80.

Although the various component parts are not described in detail, it is understood that in the coupling, acting in push-button fashion on the outer "C" shaped portions 62, 62' with a centripetal force, an opposite centrifugal motion of the inner "C" shaped portions 61, 61' with a consequent disengagement of the coupling portions 70, 80 of mask and dispenser by the retracting organs 6, 6'.

At the moment of the coupling instead, the slide portions 64, 64' function as guides in co-operation with rounded portion s72 of the projecting ring 71. An axial approaching thrust between mask and dispenser causes a centrifugal move away of the lunette retaining blades 63, 63, 63', 63', such as to allow the latter to leap-frog the projecting ring 71, followed by the snap-on engagement behind the ring 71 and the consequent locking of the coupling.

It may occur that the insertion of the projecting ring 71 fails to take place completely and perfectly in its axial run and, consequently, one or both retaining blades 63, 63, 63', 63' fails to leap-frog the projecting ring 71.

In such cases the dispenser 8 may subsequently be detached suddenly from the inspiration inlet 7 of the mask.

According to the invention, Figure 6 shows that on the outer surface of the hollow cylindrical element of the inlet 7 of the mask is obtained a pair of diametrically opposite longitudinal grooves 102 for receiving blades 63, 63, 64 and 63', 63', 64'. In Figure 6 said blades are in locking position with respect to the longitudinal grooves 102. By exerting a pressure on the antagonist springs 9, 9', one can obtain the centrifugal motion of the blades and their consequent unlocking. The longitudinal grooves 102 are obtained in a position corresponding to that of the retaining blades, their width will be at least equal to that of the retaining blades and their depth will be such as to receive the blades. The angular pitch of the blades will be equal to that of the grooves, and their number shall be equal to the number of the grooves or to a sub-multiple thereof. The radial run of the blades shall be such that when the blades are completely separated, a free passage diameter is left that is greater than or equal to the protruding ring of the inspiration inlet of the mask, and when the blades are completely approached, in addition to make stable the coupling between mask and dispenser with reference to the axial translation and hence to the possibility of extraction, the arc of circle part of the blades can reach a radius proximate to the outer one of the respective front cylindrical element of the inlet and the projections preferably coinciding with the inviting slides 64, 64' can reach a radius equal to that of the bottom of the longitudinal grooves 102. When said projections engage the longitudinal grooves they act as keys, preventing also the rotation of the dispenser about the axis of the inlet of the mask. The geometric condition for said projections 64, 64' to be engaged in the grooves coincides with the one that assures the correct execution of the stable coupling between mask and dispenser, and the empirically verifiable consequence is that it is impossible to rotate the dispenser relative to the mask.

In other words, it is possible easily to verify whether the conditions in which the dispenser can accidentally be separated from the mask are present, making sure that the rotation of the one relative to the other about the axis of coupling is prevented. The invention also achieves accessory advantages.

In many mask-to-dispenser coupling embodiments, there is no unique predefined angular position of the dispenser relative to the mask, about the axis of coupling. After wearing the mask and approaching the dispenser, each user will subjectively find an optimal position based on his/her height or on other anatomical characteristics. It is not desirable for the rotation of the dispenser relative to the mask to be allowed also in use, because the resulting positioning could be uncomfortable or hinder the field of view or freedom of movement. According to the invention, by appropriately setting the number and position of the longitudinal grooves, it is possible to set the optimal axial position of the dispenser before releasing the two push-buttons that cause the approach of the retaining blades and the penetration of the additional projections into the longitudinal grooves of the mask inlet.

Moreover, since the terminal part of the inlet is often made in multiple pieces, thanks to the present invention, the longitudinal grooves can advantageously be used by means of an appropriate key to tighten fully the front cylindrical part on the rest of the mask inlet. Lastly, the "fail to safe" mode, i.e. the fact that if the rotation of the dispenser is prevented, the connection with the mask is certainly executed in stable, complete and correct fashion, gives, if the rotation is possible (for instance because the re-approaching run of the retaining blades is not complete and thus the longitudinal grooves have not been engaged, though said blades lock the connection portion) an indication of abnormal situation even if the coupling may be stable and safe. In other words, alarms may be generated which are not strictly necessary, but in no case can a condition of actual or potential danger be ignored. Naturally, the invention thus conceived can be subj ect to numerous modifications and variations, without thereby departing from the scope of the inventive concept that characterises it.

Claims

1. Rapid coupling with automatic verification of the correct connection between dispenser and mask of a compressed air self-contained breathing apparatus for the protection of the respiratory tract, in which a mask inspiration inlet (1 ; 7), having a hollow cylindrical portion (10; 70) with a protruding end ring (11; 71) and an associated annular end portion (20; 80) of a dispenser (2; 8) are held together in detachable fashion by means of one or more radially retractable blade organs (6; 6'), each having at least a retaining blade (5; 64), characterised in that said hollow cylindrical portion (10; 70) of inspiration inlet externally has at least one or more longitudinal grooves (101 ; 102) whose width is at least equal to that of said retaining blades (5; 64) and sufficient radial depth for said retaining blades (5; 64) to be received in said longitudinal grooves (101; 102).

2. Rapid coupling as claimed in claim 1, characterised in that each of said radially retractable blade organs (6; 6') comprises an annular portion (60; 60') extending in two diametrically opposite "C" shaped elements, respectively proximal (61; 61') and distal (62; 62'), relative to the centre of the annular portion towards which they are oriented with their concavities; the proximal element (61; 61') presenting a curved lunette free end, of predetermined circumferential width, defining two locking blades (63, 63; 63', 63') separated by a slide-like projection (64; 64'), defining the retaining blade, and the distal element (62; 62') delimiting an opening (65; 65') of such size and position as to allow the passage of the proximal element (61'; 61) of another organ (6'; 6), rotated by 180°, for their mutual coaxial insertion; said longitudinal grooves (101; 102) having their width at least equal to that of said locking blades (63, 63; 63', 63') and slide-like projection (64; 64') and sufficient radial projection to receive them.

3. Rapid coupling as claimed in claims 1 and 2, characterised in that it comprises a pair of said retracting organs 6, 6', positioned coaxial, wherein said "C" shaped proximal elements 61, 61', rotated by 180° and opposite passed through the respective openings 65, 65', are loaded by respective springs 9, 9' positioned radially with centripetal effect relative to the coupling portion comprising the projecting ring 71 and the annular throat 80 and said blades and projection 63, 63, 64 and 63', 63', 64' are received in a corresponding pair of diametrically opposite longitudinal grooves 102; the egress of said blades 63, 63, 64 and 63', 63', 64' from the longitudinal grooves 102 being determined by joint pressure on said opposite distal elements (62; 62') and on the antagonist springs 9, 9'.