CA2208570A1 - Mouthpiece unit for semiclosed-circuit breathing apparatus - Google Patents
Mouthpiece unit for semiclosed-circuit breathing apparatusInfo
- Publication number
- CA2208570A1 CA2208570A1 CA002208570A CA2208570A CA2208570A1 CA 2208570 A1 CA2208570 A1 CA 2208570A1 CA 002208570 A CA002208570 A CA 002208570A CA 2208570 A CA2208570 A CA 2208570A CA 2208570 A1 CA2208570 A1 CA 2208570A1
- Authority
- CA
- Canada
- Prior art keywords
- opening
- gas
- lever
- valve
- external opening
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63C—LAUNCHING, HAULING-OUT, OR DRY-DOCKING OF VESSELS; LIFE-SAVING IN WATER; EQUIPMENT FOR DWELLING OR WORKING UNDER WATER; MEANS FOR SALVAGING OR SEARCHING FOR UNDERWATER OBJECTS
- B63C11/00—Equipment for dwelling or working underwater; Means for searching for underwater objects
- B63C11/02—Divers' equipment
- B63C11/18—Air supply
- B63C11/22—Air supply carried by diver
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
- A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes
- A61M16/22—Carbon dioxide-absorbing devices ; Other means for removing carbon dioxide
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- Health & Medical Sciences (AREA)
- General Health & Medical Sciences (AREA)
- Pulmonology (AREA)
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Biomedical Technology (AREA)
- Heart & Thoracic Surgery (AREA)
- Hematology (AREA)
- Anesthesiology (AREA)
- Animal Behavior & Ethology (AREA)
- Emergency Medicine (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Mechanical Engineering (AREA)
- Ocean & Marine Engineering (AREA)
- Respiratory Apparatuses And Protective Means (AREA)
Abstract
A mouth piece unit (6) of a semi-closed type breathing device (1) comprises a breathing air flow-through chamber (61), a gas supply port (71) for supplying to the breathing air flow-through chamber a new breathing gas at a certain flow rate which is supplied from a breathing gas cylinder, a mouth piece (62) mounted in an external opening (65), manual operation members (75, 76) held at an initial position by virtue of elastic force and adapted to be moved against the elastic force to a first operating position, an external opening closing valve (101) adapted to interlock with the movement of the manual operation members to the first operating position so as to open the external opening (65), a first open/close lever (73) for opening/closing a gas supply port (71) by interlocking with open/close of the external opening closing valve (101), and a latch lever (105) adapted to be brought into engagement with the external opening closing valve (101) which is in an open state and maintain the engaged state as long as the latch lever is held in the mouth of a diver to thereby hold the external opening closing valve (101) in the open state. When the latch lever (105) is released from the mouth, the external opening/closing valve (101) and gas supply port (71) are automatically closed.
Description
CA 02208~70 1997-06-23 .
DESCRIPTION
Title of the Invention MOUTHPIECE UNIT FOR SEMICLOSED-CIRCUIT BREATHING
APPARATUS
Technica I Field Thi s inventi on rel ates to a mouthpi ece uni t adapted for use with a semiclosed-circuit breathing apparatus constitu~ed so that exhaled air recovered from a mouthpiece is regenerated by bei ng passed through a ca rbon di oxi de adsorpti on apparatus, and a mixture of the regenerated gas and a constant flow of fresh gas for inhalation supplied from a breathing gas cyl i nder is suppl i ed to the mouthpi ece as in hal ati on gas and surplus cas is discharged to the outside.
Background Art Underwater breathi ng apparatuses can be broadl y di vi ded in to two types, one type bei ng an open- ci rcui t breathi ng apparatus and the other type a closed-circuit or semiclosed-ci rcui t breathi ng apparatus. In an open- ci rcui t breathi ng apparatus, gas that has been breathed once is expelled from the apparatus7 but a cl osed ci rcui t c,r se mi cl osed- ci rcui t breathi ng apparatu, includes an apparatus that enables gas that has been breathed to be used again.
CA 02208~70 1997-06-23 A cl osed- ci rcui t or semi cl osed- ci rcui t breathi ng apparatus general I y has the advantage of bei ng li ghter than an open- ci reui t breathi ng apparatus and permi tti ng longer dives to deeper clepths. However, since conventional closed-circuit or semi cl osed- ci rcui t breathi ng apparatuses were devel oped for specialii~ed diving applications or military use, they were equipped with only a minimum of sa~ety mechanisms, and had no mechanisms for coping with emergency situations that occur rel ati vel y easi I y. For thi s reason, ri gorous trai ni ng was requi red to use this type of apparatus, and thus it could not be readily used by recre;~tional divers.
However, the growing popularity of diving generated i ncreasi ng demand for cl osed- ci rcui t or semi cl osed- ci rcui t breathin(3 apparatuses that were not overly complicated to 1 5 operate c.n d di d not re qui re such ri gorous tr ai ni ng. Eq ui pped as it i s wi th oxygen concentrati on sensors and the li ke, a cl osed-ci rcui t breathi ng apparatus requi res consi derabl e trai ni ng wi th respect to handl i ng, control and moni tori ng. In contrast, a semi cl os~d- ci rcui t breathi ng apparatus has no such equi pment and therefore can be operated wi thout trai ni ng, so it can be handled relatively easily even by a non-expert.
Semi cl osed- ci rcui t breathi ng apparatuses that are si mpl er and easi er to use than before woul d be hi ghl y conveni ent.
There are various improvements that can be implemented to make such semi cl osed- ci rcui t breathi ng apparatuses more readi I y accessible than before. For example, since the pressure in the CA 02208~70 1997-06-23 mouthpi ece and in inhal ati on and exhal ati on passages in communi cati on with th~ mouthpi ece is about the same as the surrouncing pressure, outside water can enter the apparatus via the moul:hpi ece. If a pe rson usi ng the ap paratus is a novi ce, there is quite a high possibility that while submerged the mouthpiece may become di sl odged from the person's mouth, al I owi ng water to enter the apparatus thr~ugh the mouthpiece. This water can have an adverse effect, such as on the carbon dioxide gas adsorption apparatus~ Thus, a mechanism that does not allow the intrusion of water into the apparatus is desirable, and there is a need for a mechanism that will al~tomatically expel any water that does enter.
I n the case of an in hal ati on passage, thi s type of problem can be resolved by the provision of a check valve at the connection between the inhalation air hose and mouthpiece that onl y perrni ts a ~l ui d to pass from the in hal ati on ai r hose to the mouthpiece. However, a check valve does not solve the problem in the case of an exhalation passage, since exhaled air has to be passed from the mouthpi ece to the exhal ati on ai r hose, so a different contrivance is required.
In contrast, because an open-circuit breathing apparatus does not have an exhala~.ion air hose and the pressure inside the inhalation air hose is higher than the surrounding pressure, the entry of outside water into the apparatus via the mouthpiece does not occur.
CA 02208~70 1997-06-23 Concerni ng thi s poi nt, in Internati onal Patent Application No. W/0 95/09762 the present inventors proposed a mouthpi ece uni t that is easy to use, even by a novi ce. Thi s mouthpi~ce unit has a manually operated member, operation of which caused chewing pieces to project out from the mouthpiece, and the diver conti nues to be suppl ied with fresh breathi ng gas as long as the chewing pieces are held in the mouth. If the diver shoul d acci dental I y let th e mouthpi ece come out of hi s or her mouth, the chewi ng pi eces retract into the mouthpi ece uni t, closing off the exhalation air hose. Thus, the result is that the entry ol water is pre~ented automatically. In addition to the manually operated merr~ber, a purge lever is provided that when operated causes fresh breathi ng gas to be del i vered at a hi gh fl ow rate to purge the mout.hpiece unit of water. Thus, a diver can expel any water in the mouthpiece unit simply by operating this purge lever.
Disclosure of the Invention An obj ect of the present inventi on is to provi de a mouthpiece unit that is easy to use even by a novice.
Namel y, an obj ect of the present inventi on is to provi de a mouthpi ece uni t that automati cal I y shuts off the suppl y of brea:hing gas if the mouthpiece comes out of a diver's mouth and aut~matically prevents entry of water into the apparatus.
CA 02208~70 1997-06-23 An object of the present invention is also to provide a mouthpiece unit that is able readily to purge an interior of a mouthpiece of water.
A further obj ect of the inventi on is to provi de a mouthpi ece uni t that, when a user requi res a large amount of breathing air, is able to supply a large amount of breathing air with a simple operation.
To attai n th e above obj ect, the present inventi on provi des a mouthpi ece uni t for a semi cl osed- ci rcui t breathi ng apparatl~s, comprising:
an inhal ed~'exhal ed ai r ci rcul ati on chamber that i ncl udecs an openi ng in communi cati on wi th an exhal ati on ai r hose for ci rcul ati on of exhal ed ai r, an openi ng in communi cati on wi th an inhalation air hose for circulation of inhaled air, and an external opening in communication with an exterior;
a gas su ppl y openi ng fo r suppl yi ng th e inhal ed/exhal ed ai r ci rcul ati on chamber wi th a co nstant fl ow of fresh breathi ng gas frorn a breathing gas cylinder;
a mouthpiece attached to the external opening;
a manual I y operated member that is mai ntai ned at an initial l~osition by resilient force and can be shifted to a first operating position against the resilient force;
an external openi ng valve for openi ng the external openi ng in interl ocked operati on wi th the shi ft to the fi rst operatirg position of the manually operated member;
CA 02208~70 1997-06-23 a first lever for opening and closing the gas supply opening in interlocked operation with operation of the external opening valve; and a latch lever that engages with the external opening valve when the valve is in an open state and maintains the engagerrent to maintain the external opening valve in the open state as long as a diver is holding the lever in the diver's mouth.
With the mouthpiece unit thus constituted, when the di ver is hol di ng the mouthpi ece in hi s or her mouth, the latch 1ever W111 project between the diver's teeth or gums~ With this being the state and since the operation of the external opening valve is linked to the manually operated member, shifting the manually operated member to the first operating position will cause the external opening valve to open, thereby opening the 1~ external opening. Also, the operation of the external opening valve is linked to the operation of the first lever for opening and closing ~he gas supply opening, so opening of the external opening valve is accompanied by the opening of the first lever, thereby initiating the supply of fresh breathing gas at a constant flow rate. l~he fresh breathi ng gas conti nues to be suppl i ed at a constan~ flow rate as long as the latch lever continues to be held in the diver's mouth.
I f the di ver shoul d acci dental I y al I ow th e mouthpi ece to come out of his or her mouth~ the latch lever engagement woul d be broken and the external opening valve would therefore close.
Thus, the result is the automatic prevention of the entry of water CA 02208~70 1997-06-23 i nto th.e in hal ed/exhal ed ai r ci rcul ati on chamber vi a the mouthpi~ce and external opening.
In a further configuration of the mouthpiece unit according to the present ir!vention, the manually operated member can be moved agai nst the resi I i ent force from the fi rst to a second operating position.
A mouthpiece unit for a semiclosed-circuit breathing apparat~ls, according to this further configuration, comprises:
a purge gas supply opening for introducing gas from the breathi ng gas cyl i nder to the in hal ed/exhal ed ai r ci rcul ati on chamber at a flow rate that is higher than the constant flow rate at which breathing gas is supplied;
an openi ng for purgi ng water, sai d openi ng bei ng providecl with a check valve that communicates the inhaled /exhaled air circulation chamber with the exterior;
a valve for opening the opening for purging water in i nterl oclced operati on wi th a shi ft to a second operati ng posi ti on of the manually operated member;
a second lever for openi ng the purge gas suppl y opening in interlocked operation with the shift to the second operatin!~ position of the manually operated member; and an exhalation air hose valve for closing the opening in communi cati on wi th t~e exhal ati on ai r hose in interl ocked operation with the shift to the second operating position of the manually operated member.
CA 02208~70 1997-06-23 In the mouthpiece unit thus configured, water that has collected in the mouthpiece unit can be discharged by moving the manual 1~/ operated member to the second operati ng posi ti on.
Since operation of the valve for opening the opening for purging water is interlocked with the second lever and the exhalation air hose val ve, thi s movi ng of the manual I y operated member opens the water purging opening and the purge gas supply opening to initiate the supply of gas at a high flow rate, and closes the inhalation air hose opening. This causes a sharp rise in the pressure insi de the inhal ed/exhal ed ai r ci rcul ati on chamber, resul ti ng in any water that has col I ected bei ng di $charged together with the gas.
When needed, a large amount of breathing air can be provideci by moving the manually operated member to the second operating position.
Brief Description of the Drawings Fi gure 1 is an external perspecti ve vi ew of an embodi ment of a semi cl osed- ci rcui t breathi ng apparatus that is an embodiment of the present invention.
Figure Z is a schematic structural view showing the overal I confi gurati on of the semi cl osed- ci rcui t breathi ng apparatus.
Figure 3 is a schematic longitudinal cross-sectional vi ew of the mouthpi ece uni t of the semi cl osed- ci rcui t breathi ng apparatus.
CA 02208~70 1997-06-23 Fi gure 4 is a schemati c cross- secti onal vi ew al ong line IV-I~ of Figure 3.
Figure 5 is a schen~atic structural view of the principal parts of the mGuthpiece unit of Figure 3.
Figure 6 is a view for illustrating the supplying of inhalation gas to and the purging of water from the mouthpiece unit of Figure 3.
Fi gure 7 is a schemati c cross- secti onal vi ew al ong line Vll-\/ll of Figure 6.
Best Mo(ie for Carrying ~ut the Invention An exampl e of a se mi cl osed- ci rcui t breathi ng apparatus that uses the mouthpiece unit of the present invention will now be described, with reference to the drawings.
(Overall structure) Fi gures 1 and 2 show the overal I structure of a semi cl osed- ci rcui t breathi ng apparatus accordi ng to an embodi rrient of the inventi on. As shown in Fi gure 1, the semi cl ocied- ci rcui t breathi ng apparatus 1 of thi s exampl e is equi ppec~ with a hol I ow housi ng 2 wh i ch contai ns the component parts of the apparatus described below. One side of the housing 2 f orms a back- resti ng su rf ace 2a whi ch rests agai nst th e back of the diver~ Formed in the center of the opposing surface is an openi ng used for repl aci ng the breathi ng gas cyl i nders. The openi ng ~as a removabl e cover 2b~ Attached to the top edge of the housi ng Z is a cani ster ~ wi th a bui I t- in hori zontal carbon di oxi de CA 02208~70 1997-06-23 adsor pti on appar atus . The ca ni ster is basi cal I y cyl i ndr i cal in shape. A flexible exhalation air hose 4 is connected to the peripheral surface on one side of the canister 3, and a flexible inhalatil~n air hose 5 to the peripheral surface on the other side.
The ends of the exhalation air hose 4 and the inhalation air hose 5 are connected to a mouthpiece unit 6.
The main cornponent parts of the apparatus 1 and their connections will now be described with reference to Figure 2. As shown, an inhaled/exhaled air circulation chamber 61 is provided 1 0 i n the mouthpi ece uni t ~ in co mmuni cati on wi th the exhal ati on ai r hose ~ and inhalation air hose 5. As described above, the other ends of the exhalation air hose 4 and inhalation air hose 5 are connected to either side of the cylindrical canister 3 that has a built- in carbon dioxide adsorption apparatus 7. More specifically, the carbon dioxide adscrption apparatus 7 has an annular cross-section and is incorporated in a center portion of the canister 3, with an exhalation air passage 31 formed on one side and an i nhal ati l~n ai r passage 32 formed on the other si de. A breathi ng gas cyl i nder 8 is arranged verti cal I y in the center of the housi ng 2, belov~, the canister 3 and between an exhalation air bag 9 and an inhalath~n air bag 11~ The exhalation air bag 9 communicates with the exhalation air passage 31 of the canister 3 and the inhalation air bag 11 communicates with the inhalation air passage 32 of the canis~:er 3.
The breathing gas cylinder 8 is arranged with its gas di schar(ge outl et 81 posi ti oned at the bottom. The gas di scharge CA 02208~70 1997-06-23 outlet ~1 is connected via an on/off valve 82 (not shown) to a regulator 83. The regulator 83 is used to reduce the gas pressure to arourd 8 to 9 kg/cm2. The regulator 83 is connected by supply lines (nl~t shown) to the BC jacket and the like, and on the high-pressure si de has a re mai ni ng- pressure gage li ne connector (not shown). One of the lines connected to the regulator 83 is a gas supply l ne 84, which extends to the middle of the mouthpiece via the in hal ati on ai r passage 32 of cani ster 3 an d the in hal ati on ai r hose 5. A fl ow rate adj ustment ori f i ce 84a interposed at an intermediate position is used to adjust the flow rate to 4 to 5 liters/minute for delivery to the mouthpiece. Another line that runs to he mouthpiece unit 6 is gas supply line 85, which is used to supply gas to purge water from the interior of the mouthpiece unit 6. The remaining line, gas supply line 86, is used to supply air during emergencies. The end of the supply line 86 is located wi thi n ~he inhal ati on ai r passage 32. The inhal ati on end of the canister 3 has an auto-valve mechanism 12 which controls the opening and closing of the gas supply line 86 and the automatic release of excess gas.
The overal I gas fl ow arrangement wi l l now be descri bed. Exhal ed ai r from the mouthpi ece 62 of the mouthpi ece unit 6 passes into the exhalation air bag 9 via the exhalation air hose 4 and exhal ati on ai r passage 31. Duri ng inhal ati on, the accumul ated exhal ed ai r is passed through the carbon di oxi de adsorption apparatus 7 to remove the carbon dioxide and purify the air, which then flows through the inhalation air passage 32, CA 02208~70 1997-06-23 col I ects in the inhal ati on ai r bag 1 1 and is al so suppl i ed to the mouthph~ce uni t 6 vi a the inhal ati on ai r hose 5 for inhal ati on.
I nsi de the mouthpi ece uni t 67 a constant fl ow of fresh inhal ati on gas is mai ntai ned from the cyl i nder 8 vi a the gas suppl y li ne 84, resulting in the supply of a mixture of gases for inhalation.
(Mouthp ece unit) The mouthpi ece uni t of thi s exampl e is il I ustrated in Figures 3, 4 and 5. The mouthpiece unit 6 has a main case 63 and ,a back case 64 within ~hich the inhaled/exhaled air circulation chamber 61 is defined. The upper side of the back case 64 is an openi ng 65 to the outsi de. A mouthpi ece attachment tube 66 projects, horizontally rearward from this opening 65. The mouthpi ~ce 62 is affi ~ed to the peri phery at the end of the attachment tube 66. An exhalation opening 67 is formed in one 1 5 si de of ~:he case 63 and an in hal ati on openi ng 68 in the other si de.
The exh,~l ati on ai r hose 4 is connected to the exhal ati on openi ng 67 via a check valve 69 that only permits passage of fluid toward the exhcnl ati on ai r hose 4. Si mi I arl y, the inhal ati on ai r hose 5 is connected to the inhalaltion opening 68 via a check valve 70 that onl y permi ts passage of fl ui d away from the inhal ati on ai r hose 5.
The two gas supply lines 84 and 85 run through the inhalation opening 68 and on into the breath circulation chamber 61 in the mouthpiece unit 6.
In the inhaled/exhaled air circulation chamber 61, the bottom wal 1 63 a of the case 63 is provi ded wi th an inhal ati on gas supply opening 71 and a water-purging gas supply opening 72, CA 02208~70 1997-06-23 arranged in parallel at a constant longitudinal spacing. The gas supply line 84 is attached to the rear end of opening 71 and the gas su,~3ply line 85 is attached to the rear end of opening 72. The front ends of the openings 71 and 72 are provided with first and second levers 73 and 7~, respectively, for opening and closing the openings 71 and 72. Pushing the levers 73 and 74 down opens the openi ngs 73 and 74, allowi ng inhal ation gas to be suppl ied to the inhaled,'exhaled air circulation chamber 61.
The front surface of the case 63 is defi ned by an upper sloping wall 63b and a lower sloping wall 63c. An actuating rod 75 that passes through the upper sloping wall 63b is arranged so that it can move reciprocally in the direction of its axis. A start button 76 is affi xed at the ti p of the actuati ng rod 75 and coaxial y therewith. The start button 76 can move together with the actuating rod 75 along a guide cylinder 77 attached to the outer surface of the upper sl opi ng wal 1 63b. A cyl i ndri cal diaphragm 78 around the actuating rod 75 is used to preserve a hydraulic seal where the rod 75 passes through the upper sloping wal 1 6-3b. Insi de the inhal ed/exhal ed ai r ci rcul ati on chamber 61, the lower end 75a of the rod 75 is connected to the end 91 a of an operating lever 91 that extends horizontally and is able to rotate about il s horizontal axis. The lower end 91 b of the lever 91 is pivotally supported by a horizontal pivot pin 93 mounted in a bracket 92 that supports openi ngs 71 and 72. A sp ri ng 94 mounted on the pivot pin 93 exerts a constant force that urges the lever 91 toward the rod 75.
CA 02208~70 1997-06-23 The lower end of a fi rst in terl ocki ng lever 95 extendi ng downward ~:oward the lower slopi ng wal 1 63c is rotatabl y attached to the pivot pi n 93 . Thi s interl ocki ng lever 95 is arranged so that when the operating lever 91 is pushed beyond a fi rst operati ng posi ti on, descri bed bel ow, the lever 95 rotates as an integral unit with the lever 91. The end 95a of the lever 95 support~ a water purge opening valve 96. A purge opening 97 is f ormed in a porti on of the low er sl opi ng wal 1 63c fa ci ng the val ve 96, and is provided with a check valve 98 that only allows a fluid to fl ow to the outsi de. The outsi de of the openi ng 97 has a cap 99 perforated with numerous through-holes 99a.
The outside opening 65 in the back case 64 can be opened and closed by a valve 101. This valve 101 is supported on the upper edge of a second interl ocki ng lever 102 at a rear surface facing the inhaled/exhaled air circulation chamber 61.
The second interlocking lever 102 has an upper half 102a that extends vertically upwards and a lower half 102b that extends to the front from the lower end of the upper half 102a with a slight curvature. The lever 1()2 is pi votal I y su pported by a pi vot pi n 103 that exlends horizontally to the left and right at the curvature posi ti on 1 02c. The force of a re turn spri ng 1 03a on the pi vot pi n 103 keeps the valve 101 at the upper end pressed against the outside opening 65.
Attached to the su rf ace of the val ve 1 0 1 on the mouthpiece 62 side is an engaging member 104 having a curved surface 104a that curves back perpendicularly from the said valve CA 02208~70 1997-06-23 101 surface~ This curved surface 104a has an engaging groove 104b. [)isposed above the engaging member 104 is a latch lever 105 that extends back into the attachment tube 66, exposing the rear enl~ 105a from the mouthpiece 62. This latch lever 105 is pivotally mounted by means of a pivot pin 106 that extends horizon~:ally to each side from an intermediate position. The latch lever 105 has an engaging edge 105b for engaging with the groove l 04b.
The pivot pin 106 of the latch lever 105 is positioned at a point along the center line 66a of the attachment tube 66.
The curved surface 104a of the engaging member 104 extends from ab~ve to below the center li ne 66a, with the engagi ng groove 1 04b bei ng formed on the lower si de of the center li ne.
Consequently, as shown in Figure 3, the engaging edge 105b of the 1 5 1 atch lev/er 105 normal Iy rests on top of the curved surface 1 04a~
and the other end 105a is in contact with the lower edge of the mouthpi ce 62.
As shown in Figure 4, an engaging lever 75c extends transversel y from the exhal ati on openi ng 67 si de of the actuati ng rod 75. This engaging bar 75c abuts a third interlocking lever 1 13 affixed to a lever 112 ~hat supports an exhalation air hose valve 111 that is able to close the exhalation opening 67. Pushing in actuatir3g rod 75 causes the third interlocking lever 113 to be pushed by engaging lever 75c, resulting in an integral movement by the s~pport lever 11;2 that moves the exhalation air hose valve CA 02208~70 1997-06-23 1 1 1, th~reby maki ng it possi bl e to cl ose the exhal ati on openi ng 67.
The operation of the mouthpiece unit 6 will now be explained with reference to Figures 3 to 7 (Inhalation gas supply operation) Fi rst, the in hal ati on gas suppl y operati on wi I I be described. When the diver holds the mouthpiece 62 in his or her mouth, the exposed rear end 105a of the latch lever 105 moves f rom an incl i ned to a hori zontal state ~hat fol I ows th e center li ne 66a. Namely, as shown by Figure 6, this is because the rear end 105a of the latch lever 105 is gripped between the diver's upper and lower teeth T or gums. As a result, the engaging end 105b of the latch lever 105 is pressed onto the curved surface 1 04a of the engagin!~ member 104 on the surface of the valve 101 by the resilience of the latch lever.
In this state, the start button 76 is operated ~o push the actuati ng rod 75 to turn the end 91 a of the operati ng le ver 91 linked ~o the end of the rod 75 to the position 91A (first operating position) indicated in Figure 6 by a phantom line. The operating lever end 91a-abuts against the lower half 102b of the second interlocking lever 102, rotating the second interlocking lever 1Q2 about the pivot pin 103. As shown in Figure 5, the lower half 102bof the lever 102 has an engaging projection 10Zc extending to the side, arranged so that the curved path followed by the engaging projection 102c intersects the position of the front eclge of the first opening/closing lever 73 located below.
CA 02208~70 1997-06-23 Thus, the pivotal motion of the second interlocking lever 102 pushes down the lever 73, which opens the inhalation gas supply openi nc~ 71 to thereby ini ti ate del ivery of breathi ng gas from the gas supply line 84 to the inhaled/exhaled air circulation chamber 61, vi a the gas supply openi ng 71 . Movi ng the lever 73 thus opens the valve 101 supported by the upper half 102a of the second interlocking lever 102. This opening of the valve 101 moves the engaging member 104 e~n the valve surface forward, moving the engaging end 105b of the latch lever 105 on the curved surface 104a cf the engaging member 104 into engagement with the engaging groove 1 04b.
This pushes in the lever 73, whereby the supply of breathing inhalation gas is started, and the external opening valve 101 is opened and main~ained by the latch lever 105. The position to which the actuating rod 75 has to be inserted to form this state is; the first starting position that is reached when the start button 76 on the tip of the rod is pressed. When the start button 76 is released after this state has been achieved, the s~art button 76, actuati ng rod 75 and operating lever 91 are retracted to thei r original positions under the force of the spring 94. However, si nce the inhal ati on ai r suppl y state is mai ntai ned by the latch lever, the diver is able t:o continue to breathe.
(Water purging operation) Water in t:he mouthpi ece uni t can be purged by pressi n~ the start button 76 down as far as it can go, beyond the first operating position. The configuration is arranged so that while the track of the end 91a of the operating lever 91 connected to the end of the actuati ng rod 75 intersects the path of CA 02208~70 1997-06-23 movement of the lower end of the lower half 102b of the second i nterl orki ng lever 102 up to the fi rst operati ng posi ti on, intersection does not take place beyond that position. Therefore under the pressure of the actuati ng rod 75 the operating lever 91 is rotcted until it reaches the position of the second opening /closirg lever 74 that is located at a lower position than the first opening/closing lever 73. The end 91a of the operating lever 91 abuts agai nst an engagi ng proj ecti on 74a that extends sideways from the encl of the second opening/closing lever 74, pressirg down the lever 74. Pressing down the lever 74 opens the water-purging gas supply opening 72, allowing gas to be supplied at hi gh pressure to th e inhal ed/exhal ed ai r ci rcul ati on chamber 61 .
When at the same time the actuating rod 75 is pressed inbeyondthe firstoperatingposition, the first interlocking lever 95 starts to move integrally with the movement of the operating I ever 91, unti I at the second operati ng posi ti on the water- purgi ng openinc~ is fullyopen. This state is shown in Figure6. As shown in Figu~e 7, when the actuating rod 75 is inserted more deeply, beyond the first opera~ing position, the pressure of the engaging I ever 75c causes the exhal ati on openi ng 67 to be seal ed complel ely shut by the exhalation air hose valve 1 1 1.
The position which is the limit to which the start button 76 can be inserted is the second operating position. In this state, a high-pressure flow of gas from the gas supply line 85 is suppl i e~ to th e inhal ed/exhal ed ai r ci rcul ati on chamber 61 . As descri t3ed above, at th i s poi nt the exhal ati on openi ng 67 is cl osed, while the inhalation opening 68 is also closed, by the check valve 70. Thi s causes a sharp ri se in pressure wi thi n the inhal ed /exhaled air circulation chamber 61. As a result, water in the chamber 61 is discharged through the check valve 97 and out of the purge outlet, carried by the gas~ When the start button 76 is released, each component is urged back to its original positîon by spri ng force. Even then, the open state of the openi ng 65 is maintained by the action of the latch lever 105, and inhalation gas continues to be supplied through the inhalation gas supply opening 71. It goes without saying that when there is a temporary need for more inhalation gas, the extra gas can be suppliec~ by pressing the start button fully in.
(Operat on of shutting off the supply of inhalation gas) If the mouthpiece 62 becomes dislodged from the diver's mouth ~hen the diver is submerged, for example, the latch lever 105 again becomes free to pivot about the pivot pin 106.
Consequ.entl y, the engagi ng end 1 05b of the latch lever 105 disenga~es frorn the groove 104bof the engaging member 104. As a resul t, the second operati ng lever 102 that supports the external opening valve 101 is urged back to its original position by the force of the spring 103a on the pivot pin 103, thereby closing the external opening 65 and the gas supply opening 71.
Thus, if the mouthpi ece 62 becomes di sl odged the external opening 65 closes automatically, preventing the entry of water into the apparatus. In addi ti on, the suppl y of breathi ng gas is also shut off automatically, reducing gas wastage.
Industr al Applicability I n the semi cl osed- ci rcui t breathi ng apparatus of the present inventi on, the s;u ppl y of breathi ng gas can be ini ti ated and a water purge operation effected simply by operating the start button ~manually operated member). Operation is therefore very easy. I~oreover, if the mouthpiece becomes dislodged from the diver's mouth, the latch lever moves, automatically closing the external opening and shutting off the supply of breathing gas.
Entry o~ water can therefore be prevented. In addition, since the supply of breathing gas stops automatically if the mouthpiece becomes dislodged from the mouth, breathing gas is not wasted.
DESCRIPTION
Title of the Invention MOUTHPIECE UNIT FOR SEMICLOSED-CIRCUIT BREATHING
APPARATUS
Technica I Field Thi s inventi on rel ates to a mouthpi ece uni t adapted for use with a semiclosed-circuit breathing apparatus constitu~ed so that exhaled air recovered from a mouthpiece is regenerated by bei ng passed through a ca rbon di oxi de adsorpti on apparatus, and a mixture of the regenerated gas and a constant flow of fresh gas for inhalation supplied from a breathing gas cyl i nder is suppl i ed to the mouthpi ece as in hal ati on gas and surplus cas is discharged to the outside.
Background Art Underwater breathi ng apparatuses can be broadl y di vi ded in to two types, one type bei ng an open- ci rcui t breathi ng apparatus and the other type a closed-circuit or semiclosed-ci rcui t breathi ng apparatus. In an open- ci rcui t breathi ng apparatus, gas that has been breathed once is expelled from the apparatus7 but a cl osed ci rcui t c,r se mi cl osed- ci rcui t breathi ng apparatu, includes an apparatus that enables gas that has been breathed to be used again.
CA 02208~70 1997-06-23 A cl osed- ci rcui t or semi cl osed- ci rcui t breathi ng apparatus general I y has the advantage of bei ng li ghter than an open- ci reui t breathi ng apparatus and permi tti ng longer dives to deeper clepths. However, since conventional closed-circuit or semi cl osed- ci rcui t breathi ng apparatuses were devel oped for specialii~ed diving applications or military use, they were equipped with only a minimum of sa~ety mechanisms, and had no mechanisms for coping with emergency situations that occur rel ati vel y easi I y. For thi s reason, ri gorous trai ni ng was requi red to use this type of apparatus, and thus it could not be readily used by recre;~tional divers.
However, the growing popularity of diving generated i ncreasi ng demand for cl osed- ci rcui t or semi cl osed- ci rcui t breathin(3 apparatuses that were not overly complicated to 1 5 operate c.n d di d not re qui re such ri gorous tr ai ni ng. Eq ui pped as it i s wi th oxygen concentrati on sensors and the li ke, a cl osed-ci rcui t breathi ng apparatus requi res consi derabl e trai ni ng wi th respect to handl i ng, control and moni tori ng. In contrast, a semi cl os~d- ci rcui t breathi ng apparatus has no such equi pment and therefore can be operated wi thout trai ni ng, so it can be handled relatively easily even by a non-expert.
Semi cl osed- ci rcui t breathi ng apparatuses that are si mpl er and easi er to use than before woul d be hi ghl y conveni ent.
There are various improvements that can be implemented to make such semi cl osed- ci rcui t breathi ng apparatuses more readi I y accessible than before. For example, since the pressure in the CA 02208~70 1997-06-23 mouthpi ece and in inhal ati on and exhal ati on passages in communi cati on with th~ mouthpi ece is about the same as the surrouncing pressure, outside water can enter the apparatus via the moul:hpi ece. If a pe rson usi ng the ap paratus is a novi ce, there is quite a high possibility that while submerged the mouthpiece may become di sl odged from the person's mouth, al I owi ng water to enter the apparatus thr~ugh the mouthpiece. This water can have an adverse effect, such as on the carbon dioxide gas adsorption apparatus~ Thus, a mechanism that does not allow the intrusion of water into the apparatus is desirable, and there is a need for a mechanism that will al~tomatically expel any water that does enter.
I n the case of an in hal ati on passage, thi s type of problem can be resolved by the provision of a check valve at the connection between the inhalation air hose and mouthpiece that onl y perrni ts a ~l ui d to pass from the in hal ati on ai r hose to the mouthpiece. However, a check valve does not solve the problem in the case of an exhalation passage, since exhaled air has to be passed from the mouthpi ece to the exhal ati on ai r hose, so a different contrivance is required.
In contrast, because an open-circuit breathing apparatus does not have an exhala~.ion air hose and the pressure inside the inhalation air hose is higher than the surrounding pressure, the entry of outside water into the apparatus via the mouthpiece does not occur.
CA 02208~70 1997-06-23 Concerni ng thi s poi nt, in Internati onal Patent Application No. W/0 95/09762 the present inventors proposed a mouthpi ece uni t that is easy to use, even by a novi ce. Thi s mouthpi~ce unit has a manually operated member, operation of which caused chewing pieces to project out from the mouthpiece, and the diver conti nues to be suppl ied with fresh breathi ng gas as long as the chewing pieces are held in the mouth. If the diver shoul d acci dental I y let th e mouthpi ece come out of hi s or her mouth, the chewi ng pi eces retract into the mouthpi ece uni t, closing off the exhalation air hose. Thus, the result is that the entry ol water is pre~ented automatically. In addition to the manually operated merr~ber, a purge lever is provided that when operated causes fresh breathi ng gas to be del i vered at a hi gh fl ow rate to purge the mout.hpiece unit of water. Thus, a diver can expel any water in the mouthpiece unit simply by operating this purge lever.
Disclosure of the Invention An obj ect of the present inventi on is to provi de a mouthpiece unit that is easy to use even by a novice.
Namel y, an obj ect of the present inventi on is to provi de a mouthpi ece uni t that automati cal I y shuts off the suppl y of brea:hing gas if the mouthpiece comes out of a diver's mouth and aut~matically prevents entry of water into the apparatus.
CA 02208~70 1997-06-23 An object of the present invention is also to provide a mouthpiece unit that is able readily to purge an interior of a mouthpiece of water.
A further obj ect of the inventi on is to provi de a mouthpi ece uni t that, when a user requi res a large amount of breathing air, is able to supply a large amount of breathing air with a simple operation.
To attai n th e above obj ect, the present inventi on provi des a mouthpi ece uni t for a semi cl osed- ci rcui t breathi ng apparatl~s, comprising:
an inhal ed~'exhal ed ai r ci rcul ati on chamber that i ncl udecs an openi ng in communi cati on wi th an exhal ati on ai r hose for ci rcul ati on of exhal ed ai r, an openi ng in communi cati on wi th an inhalation air hose for circulation of inhaled air, and an external opening in communication with an exterior;
a gas su ppl y openi ng fo r suppl yi ng th e inhal ed/exhal ed ai r ci rcul ati on chamber wi th a co nstant fl ow of fresh breathi ng gas frorn a breathing gas cylinder;
a mouthpiece attached to the external opening;
a manual I y operated member that is mai ntai ned at an initial l~osition by resilient force and can be shifted to a first operating position against the resilient force;
an external openi ng valve for openi ng the external openi ng in interl ocked operati on wi th the shi ft to the fi rst operatirg position of the manually operated member;
CA 02208~70 1997-06-23 a first lever for opening and closing the gas supply opening in interlocked operation with operation of the external opening valve; and a latch lever that engages with the external opening valve when the valve is in an open state and maintains the engagerrent to maintain the external opening valve in the open state as long as a diver is holding the lever in the diver's mouth.
With the mouthpiece unit thus constituted, when the di ver is hol di ng the mouthpi ece in hi s or her mouth, the latch 1ever W111 project between the diver's teeth or gums~ With this being the state and since the operation of the external opening valve is linked to the manually operated member, shifting the manually operated member to the first operating position will cause the external opening valve to open, thereby opening the 1~ external opening. Also, the operation of the external opening valve is linked to the operation of the first lever for opening and closing ~he gas supply opening, so opening of the external opening valve is accompanied by the opening of the first lever, thereby initiating the supply of fresh breathing gas at a constant flow rate. l~he fresh breathi ng gas conti nues to be suppl i ed at a constan~ flow rate as long as the latch lever continues to be held in the diver's mouth.
I f the di ver shoul d acci dental I y al I ow th e mouthpi ece to come out of his or her mouth~ the latch lever engagement woul d be broken and the external opening valve would therefore close.
Thus, the result is the automatic prevention of the entry of water CA 02208~70 1997-06-23 i nto th.e in hal ed/exhal ed ai r ci rcul ati on chamber vi a the mouthpi~ce and external opening.
In a further configuration of the mouthpiece unit according to the present ir!vention, the manually operated member can be moved agai nst the resi I i ent force from the fi rst to a second operating position.
A mouthpiece unit for a semiclosed-circuit breathing apparat~ls, according to this further configuration, comprises:
a purge gas supply opening for introducing gas from the breathi ng gas cyl i nder to the in hal ed/exhal ed ai r ci rcul ati on chamber at a flow rate that is higher than the constant flow rate at which breathing gas is supplied;
an openi ng for purgi ng water, sai d openi ng bei ng providecl with a check valve that communicates the inhaled /exhaled air circulation chamber with the exterior;
a valve for opening the opening for purging water in i nterl oclced operati on wi th a shi ft to a second operati ng posi ti on of the manually operated member;
a second lever for openi ng the purge gas suppl y opening in interlocked operation with the shift to the second operatin!~ position of the manually operated member; and an exhalation air hose valve for closing the opening in communi cati on wi th t~e exhal ati on ai r hose in interl ocked operation with the shift to the second operating position of the manually operated member.
CA 02208~70 1997-06-23 In the mouthpiece unit thus configured, water that has collected in the mouthpiece unit can be discharged by moving the manual 1~/ operated member to the second operati ng posi ti on.
Since operation of the valve for opening the opening for purging water is interlocked with the second lever and the exhalation air hose val ve, thi s movi ng of the manual I y operated member opens the water purging opening and the purge gas supply opening to initiate the supply of gas at a high flow rate, and closes the inhalation air hose opening. This causes a sharp rise in the pressure insi de the inhal ed/exhal ed ai r ci rcul ati on chamber, resul ti ng in any water that has col I ected bei ng di $charged together with the gas.
When needed, a large amount of breathing air can be provideci by moving the manually operated member to the second operating position.
Brief Description of the Drawings Fi gure 1 is an external perspecti ve vi ew of an embodi ment of a semi cl osed- ci rcui t breathi ng apparatus that is an embodiment of the present invention.
Figure Z is a schematic structural view showing the overal I confi gurati on of the semi cl osed- ci rcui t breathi ng apparatus.
Figure 3 is a schematic longitudinal cross-sectional vi ew of the mouthpi ece uni t of the semi cl osed- ci rcui t breathi ng apparatus.
CA 02208~70 1997-06-23 Fi gure 4 is a schemati c cross- secti onal vi ew al ong line IV-I~ of Figure 3.
Figure 5 is a schen~atic structural view of the principal parts of the mGuthpiece unit of Figure 3.
Figure 6 is a view for illustrating the supplying of inhalation gas to and the purging of water from the mouthpiece unit of Figure 3.
Fi gure 7 is a schemati c cross- secti onal vi ew al ong line Vll-\/ll of Figure 6.
Best Mo(ie for Carrying ~ut the Invention An exampl e of a se mi cl osed- ci rcui t breathi ng apparatus that uses the mouthpiece unit of the present invention will now be described, with reference to the drawings.
(Overall structure) Fi gures 1 and 2 show the overal I structure of a semi cl osed- ci rcui t breathi ng apparatus accordi ng to an embodi rrient of the inventi on. As shown in Fi gure 1, the semi cl ocied- ci rcui t breathi ng apparatus 1 of thi s exampl e is equi ppec~ with a hol I ow housi ng 2 wh i ch contai ns the component parts of the apparatus described below. One side of the housing 2 f orms a back- resti ng su rf ace 2a whi ch rests agai nst th e back of the diver~ Formed in the center of the opposing surface is an openi ng used for repl aci ng the breathi ng gas cyl i nders. The openi ng ~as a removabl e cover 2b~ Attached to the top edge of the housi ng Z is a cani ster ~ wi th a bui I t- in hori zontal carbon di oxi de CA 02208~70 1997-06-23 adsor pti on appar atus . The ca ni ster is basi cal I y cyl i ndr i cal in shape. A flexible exhalation air hose 4 is connected to the peripheral surface on one side of the canister 3, and a flexible inhalatil~n air hose 5 to the peripheral surface on the other side.
The ends of the exhalation air hose 4 and the inhalation air hose 5 are connected to a mouthpiece unit 6.
The main cornponent parts of the apparatus 1 and their connections will now be described with reference to Figure 2. As shown, an inhaled/exhaled air circulation chamber 61 is provided 1 0 i n the mouthpi ece uni t ~ in co mmuni cati on wi th the exhal ati on ai r hose ~ and inhalation air hose 5. As described above, the other ends of the exhalation air hose 4 and inhalation air hose 5 are connected to either side of the cylindrical canister 3 that has a built- in carbon dioxide adsorption apparatus 7. More specifically, the carbon dioxide adscrption apparatus 7 has an annular cross-section and is incorporated in a center portion of the canister 3, with an exhalation air passage 31 formed on one side and an i nhal ati l~n ai r passage 32 formed on the other si de. A breathi ng gas cyl i nder 8 is arranged verti cal I y in the center of the housi ng 2, belov~, the canister 3 and between an exhalation air bag 9 and an inhalath~n air bag 11~ The exhalation air bag 9 communicates with the exhalation air passage 31 of the canister 3 and the inhalation air bag 11 communicates with the inhalation air passage 32 of the canis~:er 3.
The breathing gas cylinder 8 is arranged with its gas di schar(ge outl et 81 posi ti oned at the bottom. The gas di scharge CA 02208~70 1997-06-23 outlet ~1 is connected via an on/off valve 82 (not shown) to a regulator 83. The regulator 83 is used to reduce the gas pressure to arourd 8 to 9 kg/cm2. The regulator 83 is connected by supply lines (nl~t shown) to the BC jacket and the like, and on the high-pressure si de has a re mai ni ng- pressure gage li ne connector (not shown). One of the lines connected to the regulator 83 is a gas supply l ne 84, which extends to the middle of the mouthpiece via the in hal ati on ai r passage 32 of cani ster 3 an d the in hal ati on ai r hose 5. A fl ow rate adj ustment ori f i ce 84a interposed at an intermediate position is used to adjust the flow rate to 4 to 5 liters/minute for delivery to the mouthpiece. Another line that runs to he mouthpiece unit 6 is gas supply line 85, which is used to supply gas to purge water from the interior of the mouthpiece unit 6. The remaining line, gas supply line 86, is used to supply air during emergencies. The end of the supply line 86 is located wi thi n ~he inhal ati on ai r passage 32. The inhal ati on end of the canister 3 has an auto-valve mechanism 12 which controls the opening and closing of the gas supply line 86 and the automatic release of excess gas.
The overal I gas fl ow arrangement wi l l now be descri bed. Exhal ed ai r from the mouthpi ece 62 of the mouthpi ece unit 6 passes into the exhalation air bag 9 via the exhalation air hose 4 and exhal ati on ai r passage 31. Duri ng inhal ati on, the accumul ated exhal ed ai r is passed through the carbon di oxi de adsorption apparatus 7 to remove the carbon dioxide and purify the air, which then flows through the inhalation air passage 32, CA 02208~70 1997-06-23 col I ects in the inhal ati on ai r bag 1 1 and is al so suppl i ed to the mouthph~ce uni t 6 vi a the inhal ati on ai r hose 5 for inhal ati on.
I nsi de the mouthpi ece uni t 67 a constant fl ow of fresh inhal ati on gas is mai ntai ned from the cyl i nder 8 vi a the gas suppl y li ne 84, resulting in the supply of a mixture of gases for inhalation.
(Mouthp ece unit) The mouthpi ece uni t of thi s exampl e is il I ustrated in Figures 3, 4 and 5. The mouthpiece unit 6 has a main case 63 and ,a back case 64 within ~hich the inhaled/exhaled air circulation chamber 61 is defined. The upper side of the back case 64 is an openi ng 65 to the outsi de. A mouthpi ece attachment tube 66 projects, horizontally rearward from this opening 65. The mouthpi ~ce 62 is affi ~ed to the peri phery at the end of the attachment tube 66. An exhalation opening 67 is formed in one 1 5 si de of ~:he case 63 and an in hal ati on openi ng 68 in the other si de.
The exh,~l ati on ai r hose 4 is connected to the exhal ati on openi ng 67 via a check valve 69 that only permits passage of fluid toward the exhcnl ati on ai r hose 4. Si mi I arl y, the inhal ati on ai r hose 5 is connected to the inhalaltion opening 68 via a check valve 70 that onl y permi ts passage of fl ui d away from the inhal ati on ai r hose 5.
The two gas supply lines 84 and 85 run through the inhalation opening 68 and on into the breath circulation chamber 61 in the mouthpiece unit 6.
In the inhaled/exhaled air circulation chamber 61, the bottom wal 1 63 a of the case 63 is provi ded wi th an inhal ati on gas supply opening 71 and a water-purging gas supply opening 72, CA 02208~70 1997-06-23 arranged in parallel at a constant longitudinal spacing. The gas supply line 84 is attached to the rear end of opening 71 and the gas su,~3ply line 85 is attached to the rear end of opening 72. The front ends of the openings 71 and 72 are provided with first and second levers 73 and 7~, respectively, for opening and closing the openings 71 and 72. Pushing the levers 73 and 74 down opens the openi ngs 73 and 74, allowi ng inhal ation gas to be suppl ied to the inhaled,'exhaled air circulation chamber 61.
The front surface of the case 63 is defi ned by an upper sloping wall 63b and a lower sloping wall 63c. An actuating rod 75 that passes through the upper sloping wall 63b is arranged so that it can move reciprocally in the direction of its axis. A start button 76 is affi xed at the ti p of the actuati ng rod 75 and coaxial y therewith. The start button 76 can move together with the actuating rod 75 along a guide cylinder 77 attached to the outer surface of the upper sl opi ng wal 1 63b. A cyl i ndri cal diaphragm 78 around the actuating rod 75 is used to preserve a hydraulic seal where the rod 75 passes through the upper sloping wal 1 6-3b. Insi de the inhal ed/exhal ed ai r ci rcul ati on chamber 61, the lower end 75a of the rod 75 is connected to the end 91 a of an operating lever 91 that extends horizontally and is able to rotate about il s horizontal axis. The lower end 91 b of the lever 91 is pivotally supported by a horizontal pivot pin 93 mounted in a bracket 92 that supports openi ngs 71 and 72. A sp ri ng 94 mounted on the pivot pin 93 exerts a constant force that urges the lever 91 toward the rod 75.
CA 02208~70 1997-06-23 The lower end of a fi rst in terl ocki ng lever 95 extendi ng downward ~:oward the lower slopi ng wal 1 63c is rotatabl y attached to the pivot pi n 93 . Thi s interl ocki ng lever 95 is arranged so that when the operating lever 91 is pushed beyond a fi rst operati ng posi ti on, descri bed bel ow, the lever 95 rotates as an integral unit with the lever 91. The end 95a of the lever 95 support~ a water purge opening valve 96. A purge opening 97 is f ormed in a porti on of the low er sl opi ng wal 1 63c fa ci ng the val ve 96, and is provided with a check valve 98 that only allows a fluid to fl ow to the outsi de. The outsi de of the openi ng 97 has a cap 99 perforated with numerous through-holes 99a.
The outside opening 65 in the back case 64 can be opened and closed by a valve 101. This valve 101 is supported on the upper edge of a second interl ocki ng lever 102 at a rear surface facing the inhaled/exhaled air circulation chamber 61.
The second interlocking lever 102 has an upper half 102a that extends vertically upwards and a lower half 102b that extends to the front from the lower end of the upper half 102a with a slight curvature. The lever 1()2 is pi votal I y su pported by a pi vot pi n 103 that exlends horizontally to the left and right at the curvature posi ti on 1 02c. The force of a re turn spri ng 1 03a on the pi vot pi n 103 keeps the valve 101 at the upper end pressed against the outside opening 65.
Attached to the su rf ace of the val ve 1 0 1 on the mouthpiece 62 side is an engaging member 104 having a curved surface 104a that curves back perpendicularly from the said valve CA 02208~70 1997-06-23 101 surface~ This curved surface 104a has an engaging groove 104b. [)isposed above the engaging member 104 is a latch lever 105 that extends back into the attachment tube 66, exposing the rear enl~ 105a from the mouthpiece 62. This latch lever 105 is pivotally mounted by means of a pivot pin 106 that extends horizon~:ally to each side from an intermediate position. The latch lever 105 has an engaging edge 105b for engaging with the groove l 04b.
The pivot pin 106 of the latch lever 105 is positioned at a point along the center line 66a of the attachment tube 66.
The curved surface 104a of the engaging member 104 extends from ab~ve to below the center li ne 66a, with the engagi ng groove 1 04b bei ng formed on the lower si de of the center li ne.
Consequently, as shown in Figure 3, the engaging edge 105b of the 1 5 1 atch lev/er 105 normal Iy rests on top of the curved surface 1 04a~
and the other end 105a is in contact with the lower edge of the mouthpi ce 62.
As shown in Figure 4, an engaging lever 75c extends transversel y from the exhal ati on openi ng 67 si de of the actuati ng rod 75. This engaging bar 75c abuts a third interlocking lever 1 13 affixed to a lever 112 ~hat supports an exhalation air hose valve 111 that is able to close the exhalation opening 67. Pushing in actuatir3g rod 75 causes the third interlocking lever 113 to be pushed by engaging lever 75c, resulting in an integral movement by the s~pport lever 11;2 that moves the exhalation air hose valve CA 02208~70 1997-06-23 1 1 1, th~reby maki ng it possi bl e to cl ose the exhal ati on openi ng 67.
The operation of the mouthpiece unit 6 will now be explained with reference to Figures 3 to 7 (Inhalation gas supply operation) Fi rst, the in hal ati on gas suppl y operati on wi I I be described. When the diver holds the mouthpiece 62 in his or her mouth, the exposed rear end 105a of the latch lever 105 moves f rom an incl i ned to a hori zontal state ~hat fol I ows th e center li ne 66a. Namely, as shown by Figure 6, this is because the rear end 105a of the latch lever 105 is gripped between the diver's upper and lower teeth T or gums. As a result, the engaging end 105b of the latch lever 105 is pressed onto the curved surface 1 04a of the engagin!~ member 104 on the surface of the valve 101 by the resilience of the latch lever.
In this state, the start button 76 is operated ~o push the actuati ng rod 75 to turn the end 91 a of the operati ng le ver 91 linked ~o the end of the rod 75 to the position 91A (first operating position) indicated in Figure 6 by a phantom line. The operating lever end 91a-abuts against the lower half 102b of the second interlocking lever 102, rotating the second interlocking lever 1Q2 about the pivot pin 103. As shown in Figure 5, the lower half 102bof the lever 102 has an engaging projection 10Zc extending to the side, arranged so that the curved path followed by the engaging projection 102c intersects the position of the front eclge of the first opening/closing lever 73 located below.
CA 02208~70 1997-06-23 Thus, the pivotal motion of the second interlocking lever 102 pushes down the lever 73, which opens the inhalation gas supply openi nc~ 71 to thereby ini ti ate del ivery of breathi ng gas from the gas supply line 84 to the inhaled/exhaled air circulation chamber 61, vi a the gas supply openi ng 71 . Movi ng the lever 73 thus opens the valve 101 supported by the upper half 102a of the second interlocking lever 102. This opening of the valve 101 moves the engaging member 104 e~n the valve surface forward, moving the engaging end 105b of the latch lever 105 on the curved surface 104a cf the engaging member 104 into engagement with the engaging groove 1 04b.
This pushes in the lever 73, whereby the supply of breathing inhalation gas is started, and the external opening valve 101 is opened and main~ained by the latch lever 105. The position to which the actuating rod 75 has to be inserted to form this state is; the first starting position that is reached when the start button 76 on the tip of the rod is pressed. When the start button 76 is released after this state has been achieved, the s~art button 76, actuati ng rod 75 and operating lever 91 are retracted to thei r original positions under the force of the spring 94. However, si nce the inhal ati on ai r suppl y state is mai ntai ned by the latch lever, the diver is able t:o continue to breathe.
(Water purging operation) Water in t:he mouthpi ece uni t can be purged by pressi n~ the start button 76 down as far as it can go, beyond the first operating position. The configuration is arranged so that while the track of the end 91a of the operating lever 91 connected to the end of the actuati ng rod 75 intersects the path of CA 02208~70 1997-06-23 movement of the lower end of the lower half 102b of the second i nterl orki ng lever 102 up to the fi rst operati ng posi ti on, intersection does not take place beyond that position. Therefore under the pressure of the actuati ng rod 75 the operating lever 91 is rotcted until it reaches the position of the second opening /closirg lever 74 that is located at a lower position than the first opening/closing lever 73. The end 91a of the operating lever 91 abuts agai nst an engagi ng proj ecti on 74a that extends sideways from the encl of the second opening/closing lever 74, pressirg down the lever 74. Pressing down the lever 74 opens the water-purging gas supply opening 72, allowing gas to be supplied at hi gh pressure to th e inhal ed/exhal ed ai r ci rcul ati on chamber 61 .
When at the same time the actuating rod 75 is pressed inbeyondthe firstoperatingposition, the first interlocking lever 95 starts to move integrally with the movement of the operating I ever 91, unti I at the second operati ng posi ti on the water- purgi ng openinc~ is fullyopen. This state is shown in Figure6. As shown in Figu~e 7, when the actuating rod 75 is inserted more deeply, beyond the first opera~ing position, the pressure of the engaging I ever 75c causes the exhal ati on openi ng 67 to be seal ed complel ely shut by the exhalation air hose valve 1 1 1.
The position which is the limit to which the start button 76 can be inserted is the second operating position. In this state, a high-pressure flow of gas from the gas supply line 85 is suppl i e~ to th e inhal ed/exhal ed ai r ci rcul ati on chamber 61 . As descri t3ed above, at th i s poi nt the exhal ati on openi ng 67 is cl osed, while the inhalation opening 68 is also closed, by the check valve 70. Thi s causes a sharp ri se in pressure wi thi n the inhal ed /exhaled air circulation chamber 61. As a result, water in the chamber 61 is discharged through the check valve 97 and out of the purge outlet, carried by the gas~ When the start button 76 is released, each component is urged back to its original positîon by spri ng force. Even then, the open state of the openi ng 65 is maintained by the action of the latch lever 105, and inhalation gas continues to be supplied through the inhalation gas supply opening 71. It goes without saying that when there is a temporary need for more inhalation gas, the extra gas can be suppliec~ by pressing the start button fully in.
(Operat on of shutting off the supply of inhalation gas) If the mouthpiece 62 becomes dislodged from the diver's mouth ~hen the diver is submerged, for example, the latch lever 105 again becomes free to pivot about the pivot pin 106.
Consequ.entl y, the engagi ng end 1 05b of the latch lever 105 disenga~es frorn the groove 104bof the engaging member 104. As a resul t, the second operati ng lever 102 that supports the external opening valve 101 is urged back to its original position by the force of the spring 103a on the pivot pin 103, thereby closing the external opening 65 and the gas supply opening 71.
Thus, if the mouthpi ece 62 becomes di sl odged the external opening 65 closes automatically, preventing the entry of water into the apparatus. In addi ti on, the suppl y of breathi ng gas is also shut off automatically, reducing gas wastage.
Industr al Applicability I n the semi cl osed- ci rcui t breathi ng apparatus of the present inventi on, the s;u ppl y of breathi ng gas can be ini ti ated and a water purge operation effected simply by operating the start button ~manually operated member). Operation is therefore very easy. I~oreover, if the mouthpiece becomes dislodged from the diver's mouth, the latch lever moves, automatically closing the external opening and shutting off the supply of breathing gas.
Entry o~ water can therefore be prevented. In addition, since the supply of breathing gas stops automatically if the mouthpiece becomes dislodged from the mouth, breathing gas is not wasted.
Claims (2)
1. A mouthpiece unit for a semi closed-circuit breathing apparatus constituted so that exhaled air recovered from the mouthpiece unit is regenerated by being passed through a carbon dioxide adsorption apparatus, and a mixture of the regenerated gas and a constant flow of fresh gas for inhalation supplied from a breathing gas cylinder is supplied to the mouthpiece unit as inhalation gas and surplus gas is discharged to the outside, comprising:
an inhaled/exhaled air circulation chamber that includes an opening in communication with an exhalation air hose for circulation of exhaled air, an opening in communication with an inhalation air hose for circulation of inhaled air, and an external opening in communication with an exterior;
a gas supply opening for supplying the inhaled/exhaled air circulation chamber with a constant flow of fresh breathing gas from the breathing gas cylinder;
a mouthpiece attached to the external opening;
a manually operated member that is maintained at an initial position by resilient force and can be shifted to a first operating position against the resilient force;
an external opening valve for opening the external opening in interlocked operation with the shift to the first operating position of the manually operated member;
a first lever for opening and closing the gas supply opening in interlocked operation with operation of the external opening valve; and a latch lever that engages with the external opening valve when the valve is in an open state and maintains the engagement to maintain the external opening valve in the open state as long as a diver is holding the lever in the diver's mouth.
an inhaled/exhaled air circulation chamber that includes an opening in communication with an exhalation air hose for circulation of exhaled air, an opening in communication with an inhalation air hose for circulation of inhaled air, and an external opening in communication with an exterior;
a gas supply opening for supplying the inhaled/exhaled air circulation chamber with a constant flow of fresh breathing gas from the breathing gas cylinder;
a mouthpiece attached to the external opening;
a manually operated member that is maintained at an initial position by resilient force and can be shifted to a first operating position against the resilient force;
an external opening valve for opening the external opening in interlocked operation with the shift to the first operating position of the manually operated member;
a first lever for opening and closing the gas supply opening in interlocked operation with operation of the external opening valve; and a latch lever that engages with the external opening valve when the valve is in an open state and maintains the engagement to maintain the external opening valve in the open state as long as a diver is holding the lever in the diver's mouth.
2. A mouthpiece unit for a semi closed-circuit breathing apparatus according to claim 1, wherein the manually operated member can be shifted from the first operating position to a second operating position against the resilient force, further comprising:
a purge gas supply opening for introducing gas from the breathing gas cylinder to the inhaled/exhaled air circulation chamber at a flow rate that is higher than the constant flow rate at which breathing gas is supplied;
an opening for purging water, said opening being provided with a check valve that communicates the inhaled /exhaled air circulation chamber with the exterior;
a valve for opening the opening for purging water in interlocked operation with a shift to a second operating position of the manually operated member;
a second lever for opening the purge gas supply opening in interlocked operation with the shift to the second operating position of the manually operated member; and an exhalation air hose valve for closing the opening in communication with the exhalation air hose in interlocked operation with the shift to the second operating position of the manually operated member.
a purge gas supply opening for introducing gas from the breathing gas cylinder to the inhaled/exhaled air circulation chamber at a flow rate that is higher than the constant flow rate at which breathing gas is supplied;
an opening for purging water, said opening being provided with a check valve that communicates the inhaled /exhaled air circulation chamber with the exterior;
a valve for opening the opening for purging water in interlocked operation with a shift to a second operating position of the manually operated member;
a second lever for opening the purge gas supply opening in interlocked operation with the shift to the second operating position of the manually operated member; and an exhalation air hose valve for closing the opening in communication with the exhalation air hose in interlocked operation with the shift to the second operating position of the manually operated member.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002208570A CA2208570A1 (en) | 1995-10-25 | 1995-10-25 | Mouthpiece unit for semiclosed-circuit breathing apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002208570A CA2208570A1 (en) | 1995-10-25 | 1995-10-25 | Mouthpiece unit for semiclosed-circuit breathing apparatus |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2208570A1 true CA2208570A1 (en) | 1997-05-01 |
Family
ID=4160934
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002208570A Abandoned CA2208570A1 (en) | 1995-10-25 | 1995-10-25 | Mouthpiece unit for semiclosed-circuit breathing apparatus |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2208570A1 (en) |
-
1995
- 1995-10-25 CA CA002208570A patent/CA2208570A1/en not_active Abandoned
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |