U.S. patent application number 14/771717 was filed with the patent office on 2016-01-14 for valve assembly.
The applicant listed for this patent is DRAEGER SAFETY UK LIMITED. Invention is credited to Ross Alexander Clubb MacLeod, Paul Nicholas Townsend.
Application Number | 20160008639 14/771717 |
Document ID | / |
Family ID | 50241471 |
Filed Date | 2016-01-14 |
United States Patent
Application |
20160008639 |
Kind Code |
A1 |
MacLeod; Ross Alexander Clubb ;
et al. |
January 14, 2016 |
VALVE ASSEMBLY
Abstract
There is disclosed a valve assembly for controlling the supply
of breathable gas to a user, comprising a valve assembly inlet port
for a source of breathable gas and a valve assembly outlet port for
delivering breathable gas to a user. The valve assembly also
comprises a pressure reduction valve disposed between the valve
assembly inlet port and the valve assembly outlet port and
configured to reduce the pressure of breathable gas supplied at the
valve assembly inlet port in use; and a flow control valve disposed
between the pressure reduction valve and the valve assembly outlet
port and having a flow adjuster. In use, the flow adjuster can be
used to adjust the gas flow rate of the breathable gas delivered
from the valve assembly outlet port.
Inventors: |
MacLeod; Ross Alexander Clubb;
(Morpeth, Northumberland, GB) ; Townsend; Paul
Nicholas; (Cramlington, Northumberland, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DRAEGER SAFETY UK LIMITED |
Blyth, Northumberland |
|
GB |
|
|
Family ID: |
50241471 |
Appl. No.: |
14/771717 |
Filed: |
February 26, 2014 |
PCT Filed: |
February 26, 2014 |
PCT NO: |
PCT/GB2014/050577 |
371 Date: |
August 31, 2015 |
Current U.S.
Class: |
128/205.24 ;
137/613 |
Current CPC
Class: |
A62B 17/04 20130101;
A62B 7/02 20130101; A62B 18/02 20130101; F16L 37/28 20130101; A62B
9/02 20130101; G05D 16/04 20130101; A62B 17/006 20130101; A62B 7/12
20130101; F16L 37/02 20130101; F16L 15/04 20130101; A62B 9/022
20130101; F16L 55/07 20130101; F16K 3/0227 20130101; G05D 7/01
20130101; F16L 29/007 20130101; F16L 37/08 20130101; A62B 9/04
20130101 |
International
Class: |
A62B 9/02 20060101
A62B009/02; A62B 9/04 20060101 A62B009/04; A62B 7/02 20060101
A62B007/02; G05D 7/01 20060101 G05D007/01; G05D 16/04 20060101
G05D016/04 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 1, 2013 |
GB |
1303731.2 |
Mar 1, 2013 |
GB |
1303732.0 |
Mar 1, 2013 |
GB |
1303733.8 |
Claims
1. Breathing apparatus equipment for supplying breathable gas to a
user, comprising: a manifold having a manifold inlet port for a
source of breathable gas and at least one manifold outlet port,
wherein the manifold is arranged to be attached to the user; and a
valve assembly connected to the manifold for controlling the supply
of breathable gas to the user, the valve assembly comprising: a
valve assembly inlet port which is fluidically connected to the
manifold outlet port; a valve assembly outlet port for delivering
breathable gas to a user; and first and second stages between the
valve assembly inlet port and the valve assembly outlet port,
wherein the second stage is distinct from and located downstream of
the first stage; wherein the first stage comprises a pressure
reduction configured to reduce the pressure of breathable gas
supplied at the valve assembly inlet port in use; and wherein the
second stage comprises a flow control valve having a flow adjuster
which in use can be used to adjust the gas flow rate of the
breathable gas delivered from the valve assembly outlet port.
2. Breathing apparatus equipment according to claim 1, further
comprising a strap arranged to be worn by the user; and a holder
coupled to the strap and to which the manifold is attached.
3. Breathing apparatus equipment according to claim 1, wherein the
flow control valve and the pressure reduction valve are
separate.
4. Breathing apparatus equipment according to claim 1, wherein the
valve assembly is configured such that the gas flow rate of the
breathable gas delivered from the valve assembly outlet port is
substantially independent of the pressure of the breathable gas
supplied at the valve assembly inlet port.
5. Breathing apparatus equipment according to claim 1, wherein the
valve assembly is configured such that the in use the flow adjuster
can be used to adjust the flow rate without substantially changing
the pressure of the breathable gas delivered from the valve
assembly outlet port.
6. (canceled)
7. Breathing apparatus equipment according to claim 1, wherein the
flow control valve comprises one or more flow passageways for
breathable gas, the overall size of which can be adjusted in use by
the flow adjuster so as to adjust the gas flow rate of the
breathable gas delivered from the valve assembly outlet port.
8. Breathing apparatus equipment according to claim 7, wherein the
overall size of the one or more flow passageways has a minimum size
so as to ensure that in use the gas flow rate of the breathable gas
delivered from the valve assembly outlet port is kept above a
minimum.
9. Breathing apparatus equipment according to claim 1, wherein the
flow control valve comprises a first member having a first orifice
opening and a second adjacent member having a second orifice
opening, wherein in use the flow adjuster can be used to move one
of the members relative to the other member so as to vary the
degree of alignment of the first and second orifice openings,
thereby adjusting the size of an orifice passageway defined by the
first and second orifice openings and hence the gas flow rate of
the breathable gas delivered from the valve assembly outlet
port.
10. Breathing apparatus equipment according to claim 9, wherein the
first member is a first plate and the second member is a second
plate.
11. (canceled)
12. Breathing apparatus equipment according to claim 9, wherein the
flow control valve comprises a bypass passageway having a minimum
size so as to ensure that in use the gas flow rate of the
breathable gas delivered from the valve assembly outlet port is
kept above a minimum.
13. Breathing apparatus equipment according to claim 12, wherein
the first and second members comprise first and second bypass
openings that in use are always aligned to at least some degree
regardless of the relative position of the first and second
members.
14. Breathing apparatus equipment according to claim 13, wherein
the degree of alignment of the first and second bypass openings is
fixed so that the size of the bypass passageway is fixed.
15. Breathing apparatus equipment according to claim 1, wherein the
pressure reduction valve comprises a pressure chamber downstream of
a valve seat and a corresponding valve member, the valve member
being resiliently biased away from the valve seat to an open
position in which breathable gas supplied at the valve assembly
inlet port can flow into the chamber, wherein in use, breathable
gas in the pressure chamber acts against the bias to move the valve
member towards a closed position.
16. Breathing apparatus equipment according to claim 15, wherein
the valve member is coupled to a piston slidably disposed within
the pressure chamber and upon which in use breathable gas in the
pressure chamber acts to move the valve member towards a closed
position.
17. Breathing apparatus equipment according to claim 16, wherein
the valve member is attached to the piston by a piston shaft and
wherein a fluid passageway extends from the valve member through
the piston and piston shaft and opens into the pressure
chamber.
18. Breathing apparatus equipment according to claim 17, wherein
the tip of the piston shaft forms the valve member.
19. Breathing apparatus equipment according claim 1, wherein the
pressure reduction valve and the flow control valve are disposed
within a common housing.
20. A valve assembly for controlling the supply of breathable gas
to a user, comprising: a valve assembly inlet port for a source of
breathable gas; a valve assembly outlet port for delivering
breathable gas to a user; a pressure reduction valve disposed
between the valve assembly inlet port and the valve assembly outlet
port and configured to reduce the pressure of breathable gas
supplied at the valve assembly inlet port in use; and a flow
control valve disposed between the pressure reduction valve and the
valve assembly outlet port and having a flow adjuster which in use
can be used to adjust the gas flow rate of the breathable gas
delivered from the valve assembly outlet port, wherein the flow
control valve comprises one or more flow passageways for breathable
gas, the overall size of which can be adjusted in use by the flow
adjuster so as to adjust the gas flow rate of the breathable gas
delivered from the valve assembly outlet port, wherein the overall
size of the one or more flow passageways has a minimum size so as
to ensure that in use the gas flow rate of the breathable gas
delivered from the valve assembly outlet port is kept above a
minimum.
21-42. (canceled)
43. Breathing apparatus, comprising: breathing apparatus equipment
in accordance with claim 1; a breathable gas delivery device for
delivering breathable gas to a user with a first flexible conduit
fluidically coupled between the breathable gas delivery device and
the valve assembly outlet port; and a source of breathable gas with
a second flexible conduit fluidically coupled between the source of
breathable gas and the manifold inlet port.
44. Breathing apparatus according to claim 43, wherein the
breathable gas delivery device is a facemask or a hood or a
protection suit.
Description
BACKGROUND
[0001] The invention relates to a valve assembly for controlling
the supply of breathable gas to a user.
[0002] When working in an environment in which the atmosphere is
either contaminated or otherwise unsuitable for breathing it is
necessary to use breathing apparatus. One option is to use
self-contained breathing apparatus (SCBA) which typically comprises
a cylinder of breathable gas that is carried by the user. Whilst
this may be suitable for some applications, the equipment worn by
the user may be bulky and may therefore restrict the activities
that the user can carry out, and the size of the cylinder that the
user can carry may not contain enough breathable gas for a suitable
working duration.
[0003] It is therefore known for the breathable gas to be supplied
to the wearer from a large cylinder that is either static or
moveable on a trolley, or from a breathable gas airline installed
within the building. The breathable gas is typically delivered to
the user through a facemask or hood or protection suit that is
fluidically connected to the source of breathable gas, such as a
tank or airline, with a flexible conduit. The breathable gas may be
supplied on demand, by using a lung demand valve for example, or
may be supplied constantly.
[0004] If the breathable gas is supplied constantly in a constant
flow arrangement it is necessary to reduce the pressure of the gas
and control the flow rate of the gas. It is known to use a valve
assembly to achieve this. In previously considered arrangements
valve assembly arrangements the flow rate is entirely dependent on
the supply pressure. Therefore, if the supply pressure drops, the
flow rate drops. Similarly, it may not be possible to control the
flow rate supplied without altering the pressure delivered. This
may be problematic as the supply pressure may decrease as the
source of breathable gas is depleted and/or as more users connect.
This may be a particular problem where multiple users connect to a
large tank or ring main.
[0005] It is therefore desirable to provide an improved valve
assembly.
SUMMARY OF THE INVENTION
[0006] An exemplary embodiment of the present invention comprises
breathing apparatus equipment for supplying breathable gas to a
user, comprising a manifold having a manifold inlet port for a
source of breathable gas and at least one manifold outlet port,
wherein the manifold is arranged to be attached to the user; and a
valve assembly connected to the manifold for controlling the supply
of breathable gas to the user, the valve assembly comprising a
valve assembly inlet port which is fluidically connected to the
manifold outlet port; a valve assembly outlet port for delivering
breathable gas to a user; and first and second stages between the
valve assembly inlet port and the valve assembly outlet port,
wherein the second stage is distinct from and located downstream of
the first stage; wherein the first stage comprises a pressure
configured to reduce the pressure of breathable gas supplied at the
valve assembly inlet port in use; and wherein the second stage
comprises a flow control valve having a flow adjuster which in use
can be used to adjust the gas flow rate of the breathable gas
delivered from the valve assembly outlet port.
[0007] Another exemplary embodiment of the present invention
comprises a valve assembly for controlling the supply of breathable
gas to a user, comprising a valve assembly inlet port for a source
of breathable gas; a valve assembly outlet port for delivering
breathable gas to a user; a pressure reduction valve disposed
between the valve assembly inlet port and the valve assembly outlet
port and configured to reduce the pressure of breathable gas
supplied at the valve assembly inlet port in use; and a flow
control valve disposed between the pressure reduction valve and the
valve assembly outlet port and having a flow adjuster which in use
can be used to adjust the gas flow rate of the breathable gas
delivered from the valve assembly outlet port, wherein the flow
control valve comprises one or more flow passageways for breathable
gas, the overall size of which can be adjusted in use by the flow
adjuster so as to adjust the gas flow rate of the breathable gas
delivered from the valve assembly outlet port, wherein the overall
size of the one or more flow passageways has a minimum size so as
to ensure that in use the gas flow rate of the breathable gas
delivered from the valve assembly outlet port is kept above a
minimum.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Embodiments of the invention will now be described, by way
of example, with reference to the accompanying drawings, in
which:
[0009] FIG. 1 schematically shows a compressed airline breathing
apparatus including a waist mountable manifold;
[0010] FIG. 2 schematically shows the manifold of the waist
mountable manifold of FIG. 1;
[0011] FIG. 3 schematically shows a perspective view of the holder
of the waist mountable manifold of FIG. 1;
[0012] FIG. 4 schematically shows a rear view of the holder of the
waist mountable manifold of FIG. 1;
[0013] FIG. 5 schematically shows the breathing apparatus equipment
with the manifold removed from the strap-mounted holder;
[0014] FIG. 6 schematically shows a rear view of the breathing
apparatus equipment with the manifold located in the holder;
[0015] FIG. 7 schematically shows a front view of the manifold
located in the holder in a first orientation;
[0016] FIG. 8 schematically shows a front view of the manifold
located in the holder in a second orientation;
[0017] FIG. 9 schematically shows the arrangement of FIG. 7 with a
banjo fitting attached to the manifold inlet port;
[0018] FIG. 10 schematically shows a manifold suitable for a
constant flow delivery device having a control valve attached to a
manifold outlet port;
[0019] FIG. 11 schematically shows a perspective view of the
control valve of FIG. 10;
[0020] FIG. 12 schematically shows a cross-sectional view through
the control valve with the pressure reduction valve in an open
position;
[0021] FIG. 13 schematically shows a cross-sectional view through
the control valve with the pressure reduction valve in a closed
position;
[0022] FIG. 14 schematically shows a plan view of the first and
second plates of the flow control valve in a maximum flow
state;
[0023] FIG. 15 schematically shows a plan view of the first and
second plates of the flow control valve in a reduced flow
state;
[0024] FIG. 16 schematically shows a perspective view of an adapter
suitable for use with a constant flow delivery device;
[0025] FIG. 17 schematically shows a cross-sectional view through
the adapter of FIG. 16;
[0026] FIG. 18 schematically shows a perspective view of the
adapter body of the adapter of FIG. 16;
[0027] FIG. 19 schematically shows a perspective view of the
rotatable part of the adapter of FIG. 16;
[0028] FIG. 20 schematically shows a perspective view of the
adapter of FIG. 16 with the blanking plug located within the
ambient air inlet port;
[0029] FIG. 21 schematically shows the adapter of FIG. 16 with the
rotatable part rotated to a different angular position;
[0030] FIG. 22 schematically shows a cross-sectional view through
an adapter according to a second embodiment;
[0031] FIG. 23 schematically shows a perspective view of an adapter
suitable for use with a constant flow delivery device according to
a third embodiment;
[0032] FIG. 24 schematically shows a cross-sectional view through
the adapter of FIG. 23;
[0033] FIG. 25 schematically shows a perspective view of the
adapter body of the adapter of FIG. 23;
[0034] FIG. 26 schematically shows a perspective view of the
rotatable part of the adapter of FIG. 23;
[0035] FIG. 27 schematically shows the adapter of FIG. 23 with the
rotatable part rotated to a different angular position;
[0036] FIG. 28 schematically shows a close-up of the sealing
arrangement; and
[0037] FIG. 29 schematically shows a close-up of the sealing
arrangement with the lip portion of the lip seal deflected.
DETAILED DESCRIPTION
[0038] According to an aspect of the invention there is provided a
valve assembly for controlling the supply of breathable gas to a
user, comprising: a valve assembly inlet port for a source of
breathable gas; a valve assembly outlet port for delivering
breathable gas to a user; a pressure reduction valve disposed
between the valve assembly inlet port and the valve assembly outlet
port and configured to reduce the pressure of breathable gas
supplied at the valve assembly inlet port in use; and a flow
control valve disposed between the pressure reduction valve and the
valve assembly outlet port and having a flow adjuster which in use
can be used to adjust the gas flow rate of the breathable gas
delivered from the valve assembly outlet port. The valve assembly
may be referred to as an integrated flow control and reducer valve.
The valve assembly may be particularly suitable for constant flow
breathing apparatus in which breathable gas is continuously
supplied to a user from a source of breathable gas such as a
cylinder, tank, compressor or compressed air network (or ring main)
installed in a building.
[0039] The pressure reduction valve may be arranged to reduce the
pressure to 10 bar or less, 8 bar or less, 6 bar or less, 4 bar or
less, or 2.5 bar or less. The flow control valve may be capable of
adjusting the flow rate between 0-600 l/min, 50-500 l/min, 100-400
l/min, or 170-350 l/min.
[0040] The flow control valve and the pressure reduction valve may
be separate valves. In other words, the flow control valve and
pressure reduction valves may be separate mechanical assemblies
which may or may not be disposed in a single housing.
[0041] The valve assembly may be configured such that the gas flow
rate of the breathable gas delivered from the valve assembly outlet
port is substantially independent of the pressure of the breathable
gas supplied at the valve assembly inlet port. The flow rate may be
independent of supply pressure over a range. The range may be
within 0-20 bar, 0.5-18 bar, 1-16 bar, 1.5-14 bar, 2-14 bar, 2.5-12
bar, or 2.8-10 bar. If the valve assembly is used with constant
flow breathing apparatus, this may mean that the flow rate of the
breathable gas supplied to the user does not change as the supply
pressure of the breathable gas changes. During the use of breathing
apparatus, the supply pressure of the source of breathable gas may
reduce as more users connect to the same source of breathable gas,
or as the source of breathable gas is depleted. The valve assembly
may be configured such that the in use the flow adjuster can be
used to adjust the flow rate without substantially changing the
pressure of the breathable gas delivered from the valve assembly
outlet port.
[0042] The flow adjuster may comprise a rotatable knob. This may be
easily adjustable by the user.
[0043] The flow control valve may comprise at least one flow
passageway for breathable gas, the size of which can be adjusted in
use by the flow adjuster so as to adjust the gas flow rate of the
breathable gas delivered from the valve assembly outlet port. There
may be multiple separate flow passageways, or a single passageway.
If there are multiple flow passageways, each one may be of a
variable size, or one or more may be fixed and one or more may be
variable. The at least one flow passageway may have a minimum size
so as to ensure that in use the gas flow rate of the breathable gas
delivered from the valve assembly outlet port is kept above a
minimum. If there is a single passageway it may have a minimum size
to which it can be reduced, if there are multiple passageways one
may be fixed open and one may be variable between fully open and
fully closed. As will be appreciated, other alternatives are
possible.
[0044] The flow control valve may comprise a first member, such as
a plate or tube, having a first orifice opening and a second
adjacent member, such as a plate or tube, having a second orifice
opening, wherein in use the flow adjuster may be used to move one
of the members relative to the other member so as to vary the
degree of alignment of the first and second orifice openings,
thereby adjusting the size of an orifice passageway defined by the
first and second orifice openings and hence the gas flow rate of
the breathable gas delivered from the valve assembly outlet port.
The first and/or second member may be rotatable or slidable, for
example. The flow adjuster may be coupled to the first or second
member. The first member may be a first plate and the second member
may be a second plate. The first and second plates may be parallel
and in contact with each other. One of the members may be fixed and
the other may be moveable by the flow adjuster. For example, the
first plate may be rotatable and the second plate may be fixed.
[0045] The flow control valve may comprise a bypass passageway
having a minimum size so as to ensure that in use the gas flow rate
of the breathable gas delivered from the valve assembly outlet port
is kept above a minimum. The minimum may be at least 50 l/min, 100
l/min, 150 l/min, or 170 l/min. The first and second members may
comprise first and second bypass openings that in use are always
aligned to at least some degree regardless of the relative position
of the first and second members. The valve assembly may be arranged
such that the flow adjuster can be used to rotate one of the
members about a rotational axis with respect to the other member so
as to vary the degree of alignment of the first and second
openings. The first and second bypass openings may be coaxial with
one another and the rotational axis. The degree of alignment of the
first and second bypass openings may be fixed so that the size of
the bypass passageway is fixed. If the members are plates such as
discs, the bypass openings may extend through the centre of the
discs such that they are coaxial.
[0046] The pressure reduction valve may comprise a pressure chamber
downstream of a valve seat and a corresponding valve member. The
pressure chamber may be upstream of the flow control valve. The
valve member may be resiliently biased away from the valve seat to
an open position in which breathable gas supplied at the valve
assembly inlet port can flow into the chamber. The valve member may
be resiliently biased by any suitable means such as a spring or a
mass of resilient material. In use, breathable gas in the pressure
chamber may act against the bias to move the valve member towards a
closed position. The valve member may be coupled to a piston
slidably disposed within the pressure chamber and upon which in use
breathable gas in the pressure chamber acts to move the valve
member towards a closed position. The valve member may be attached
to the piston by a piston shaft. A fluid passageway may extend from
the valve member through the piston and piston shaft and open into
the pressure chamber. The tip of the piston shaft may form the
valve member.
[0047] The pressure reduction valve and the flow control valve may
be at least partially disposed within a common housing. The
pressure reduction valve and flow control valve may be sealed
within a common housing. The flow adjuster may be disposed outside
of the housing so that it can be easily adjusted. The valve
assembly inlet port may be the pressure reduction valve inlet, the
pressure reduction valve outlet may be in direct fluid
communication with the flow control valve inlet and the flow
control valve outlet may be the valve assembly outlet port. The
valve assembly inlet and outlet ports may be formed in a housing
and may be formed in opposing ends of a housing. The valve assembly
inlet port may be a threaded inlet port or a push-fit inlet port
and similarly the valve assembly outlet may be a threaded outlet
port or a push-fit outlet port.
[0048] The invention also relates to breathing apparatus equipment,
comprising: a manifold having a manifold inlet port for a source of
breathable gas and at least one manifold outlet port; a valve
assembly in accordance with any statement herein, wherein the valve
assembly inlet port is fluidically connected to the manifold outlet
port. The manifold may be arranged to be attached to a the user.
The valve assembly may be connected to the manifold for controlling
the supply of breathable gas to the user. The equipment may further
comprise a strap arranged to be worn by the user; and a holder
coupled to the strap and to which the manifold is attached.
[0049] The invention also relates to breathing apparatus,
comprising: breathing apparatus equipment in accordance with any
statement herein; a breathable gas delivery device for delivering
breathable gas to a user with a first flexible conduit fluidically
coupled between the breathable gas delivery device and the valve
assembly outlet port; and a source of breathable gas with a second
flexible conduit fluidically coupled between the source of
breathable gas and the manifold inlet port. The breathable gas
delivery device may be a facemask or a hood or a protection suit.
The source of breathable gas may be a tank, a cylinder, a
compressor or a compressed air network (or ring main) installed
within a building.
[0050] According to an aspect of the invention there is provided a
fluid adapter for a breathable gas delivery device, such as a
facemask, hood or protection suit, for delivering breathable gas to
a user, the fluid adapter comprising: an adapter body defining an
adapter chamber; a pressurised gas inlet port in fluid
communication with the adapter chamber and arranged to be
fluidically coupled to a source of pressurised breathable gas; an
ambient air inlet port arranged to provide fluid communication
between the adapter chamber and ambient air outside of the fluid
adapter; an adapter outlet port in fluid communication with the
adapter chamber and arranged to be fluidically coupled to a
delivery device gas inlet port of the breathable gas delivery
device; and an adapter connector arranged to connect the fluid
adapter to the breathable gas delivery device such that the adapter
outlet port is fluidically coupled to the delivery device gas inlet
port. The adapter may allow either ambient air or pressurised
breathable gas to be supplied to the user. The adapter may be
particularly suitable for constant flow breathing apparatus in
which pressurised breathable gas is continuously supplied to a user
from a source of breathable gas such as a cylinder, tank,
compressor or compressed air network (or ring main) installed in a
building.
[0051] The pressurised gas inlet port may be provided with a
pressurised gas connector for fluidically and/or physically
connecting a flexible conduit for supplying pressurised breathable
gas to the pressurised gas inlet port.
[0052] The fluid adapter may further comprise a valve disposed
between the ambient air inlet port and the adapter chamber. This
may mean that the valve is disposed between, and separates, the
ambient air inlet port from both the pressurised gas inlet and the
adapter outlet port. The valve may be a one-way valve arranged so
as to permit fluid flow into the adapter chamber through the
ambient air inlet port but restrict or prevent fluid flow out of
the adapter chamber through the ambient air inlet port. The valve
may be a diaphragm one-way valve. The valve may prevent pressurised
breathable gas supplied through the pressurised gas inlet port from
exiting the adapter chamber through the ambient air inlet port.
When pressurised breathable gas is supplied through the pressurised
air inlet port, this may close the valve thereby preventing ambient
air from being inhaled into the adapter chamber through the ambient
air inlet port.
[0053] The fluid adapter may further comprise a filter disposed
between the ambient air inlet port and the adapter chamber. The
filter may be disposed between the ambient air inlet port and both
the pressurised gas inlet port and the adapter outlet port. The
filter may be arranged to filter ambient air inhaled through the
ambient air inlet port. The filter may be disposed between the
ambient air inlet port and the valve.
[0054] The fluid adapter may further comprise a blanking plug that
is located or is arranged to be located within the ambient air
inlet port so as to prevent fluid flow through the ambient air
inlet port. When located within the ambient air inlet port this may
seal the ambient air inlet port preventing ambient air from being
inhaled through the ambient air inlet port. The blanking plug may
be threadedly engaged with, or arranged to be threadedly engaged
with the ambient air inlet port. Alternatively the blanking plug
may be arranged for a push or snap fit.
[0055] The fluid adapter may further comprise an excess flow valve
which is arranged to open and close in response to the pressure
within the adapter chamber so as to vent exhaled air, or gas,
within the adapter chamber to the atmosphere. When pressurised
breathable gas is supplied through the pressurised gas inlet port,
if the flow rate is in excess of that which is required by the
user, the excess gas can exit to the atmosphere through the excess
flow valve. The excess flow valve may be a one-way valve so that it
does not permit ambient air from entering the adapter chamber. The
fluid adapter may further comprise an excess flow passageway
extending through the adapter body into the adapter chamber,
wherein the excess flow valve is arranged to control the flow of
exhaled air, or gas, through the excess flow passageway. The excess
flow valve may be resiliently biased to a closed position and may
be arranged to move to an open position when the pressure within
the adapter chamber is above a threshold. The excess flow valve may
open when the user exhales as the pressure within the adapter
chamber increases. The excess flow valve may be a one-way diaphragm
valve or a sleeve valve.
[0056] The adapter connector may comprise a threaded adapter outlet
port, a snap-fit adapter outlet port or a press-fit adapter outlet
port.
[0057] At least one fluid passageway may extending through the
adapter body into the adapter chamber. The adapter body may have a
generally cylindrical outer wall portion through which at least one
fluid passageway extends into the adapter chamber. There may be
multiple fluid passageways circumferentially distributed about the
body or cylindrical outer wall portion at substantially the same
axial position. The body or generally cylindrical outer wall
portion may have a stepped profile of various diameters or may be
of a constant diameter. The fluid adapter may further comprise a
rotatable part comprising an annular member and the pressurised gas
inlet port. The pressurised gas inlet port may extend from the
annular member in a direction having a radial component. The
rotatable part may be rotatably coupled to the adapter body with
the annular member surrounding the adapter body, such as the
cylindrical outer wall portion of the adapter body, and with the
pressurised gas inlet port in fluid communication with the adapter
chamber through the at least one fluid passageway. The annular
member may be sealed to the body or cylindrical outer wall portion
axially either side of the at least one fluid passageway. The
rotatable part may be rotatable to a plurality of angular positions
with respect to the adapter body so as to alter the position of the
pressurised gas inlet port. In each of the angular positions the
pressurised gas inlet port may be in fluid communication with the
adapter chamber. The pressurised gas inlet port may be in fluid
communication with the adapter chamber regardless of the angular
position of the rotatable part. Alternatively, the pressurised gas
inlet port may only be in fluid communication with the adapter
chamber when it is in one of a set number of angular positions.
[0058] The fluid adapter may further comprise an indexing feature
defining a plurality of discrete angular positions to which the
rotatable part can be rotated with respect to the adapter body.
There may be at least two, at least four, at least six, at least
eight, or at least ten discrete angular positions. The indexing
feature may be integrally formed with the rotatable part and the
adapter body. The indexing feature may comprise a plurality of
circumferentially spaced first formations formed on either the
adapter body or the rotatable part and at least one corresponding
second formation formed on the other of the adapter body and the
rotatable part. The number of second formations may be the same as
the number of first formations and may be spaced in the same way.
Alternatively, there may be a single second formation and multiple
first formations. In one arrangement there are multiple first and
second formations that are both evenly circumferentially spaced
with the number of first formations an integer multiple of the
number of second formations. The first and/or second formations may
be evenly circumferentially distributed. First and second
formations may be arranged to engage with one another at each of
the plurality discrete angular positions. The first formations may
comprise recesses or projections and the at least one second
formation may comprise the other of recesses or projections. The
circumferential spacing of the first formations may define the
plurality of discrete angular positions. First formations may be
formed on either the adapter body, such as the outer surface of the
cylindrical outer wall portion of the adapter body, or the inner
surface of the annular member. The at least one second formation
may be formed on the other of the outer surface of the cylindrical
outer wall portion and the inner surface of the annular member. The
adapter body, or the cylindrical outer wall portion of the adapter
body, or the annular member may be resiliently deformable. This may
allow the first and second formations to engage, and be disengaged
by relative rotation. The indexing feature may inhibit the movement
of the rotatable part away from a particular discrete angular
position. Movement of the rotatable part away from a particular
angular position may be achieved by applying a sufficient rotation
force between the adapter body and the rotatable part.
[0059] The adapter may further comprise an annular fluid channel
between the adapter body and the annular member into which the
pressurised gas inlet port and the at least one fluid passageway
opens so as to ensure fluid communication between the pressurised
gas inlet port and the adapter chamber regardless of the angular
position of the rotatable part. The inner surface of the annular
member and/or the outer surface of the cylindrical outer wall
portion may be provided with an annular fluid channel into which
the pressurised gas inlet port or the at least one fluid passageway
opens. The annular fluid channel may be aligned, such as axially
aligned, so as to ensure fluid communication between the
pressurised gas inlet port and the adapter chamber regardless of
the angular position of the rotatable part. If there are multiple
fluid passageways they may all be aligned with the annular fluid
channel.
[0060] The fluid adapter may further comprise a sealing arrangement
sealing between the adapter body and the annular member. The
sealing arrangement may comprise first and second seals disposed
either side of the at least one fluid passageway. The sealing
arrangement may comprise at least one lip seal having a lip portion
which seals against a sealing surface formed by either the adapter
body or the annular member. The lip seal may comprise a main ring
portion integrally formed with the lip portion. The lip seal may be
annular. The lip seal may be mounted to the adapter body or the
annular member. The lip portion may extend between the adapter body
and the annular member. The lip portion may be resiliently
deformable. The lip portion may extend in a direction inclined to
the radial direction. The lip portion may extend in a direction
that is inclined away from the at least one fluid passageway. The
lip portion may be inclined in a direction away from the pressure
side of the adapter chamber. The lip seal may be configured such
that a pressure within the adapter chamber above a threshold causes
the lip portion to resiliently deflect away from the sealing
surface, thereby allowing gas within the adapter chamber to be
vented out of the adapter chamber. The lip seal may therefore
provide the functionality of an excess flow or pressure relief
valve.
[0061] The invention also relates to breathing apparatus equipment,
comprising: a breathable gas delivery device for delivering
breathable gas to a user and having a delivery device gas inlet
port; and a fluid adapter in accordance with any statement herein;
wherein the adapter connector connects the fluid adapter to the
breathable gas delivery device such that the adapter outlet port is
fluidically coupled to the delivery device gas inlet port. The
breathable gas delivery device may be a facemask or a hood or a
protection suit.
[0062] The invention also relates to breathing apparatus,
comprising: a manifold having a manifold inlet port for a source of
breathable gas and at least one manifold outlet port; a strap
arranged to be worn by the user; a holder coupled to the strap and
to which the manifold is attached; breathing apparatus equipment in
accordance with any statement herein with a first flexible conduit
fluidically coupled between the pressurised gas inlet port and the
manifold outlet port; and a source of pressurised breathable gas
with a second flexible conduit fluidically coupled between the
pressurised source of breathable gas and the manifold inlet port.
The source of breathable gas may be a tank, a cylinder, a
compressor or a compressed air network (or ring main) installed
within a building.
[0063] According to an aspect of the invention there is provided a
fluid coupling, comprising: a body defining a fluid chamber at
least one fluid passageway extending through the body into the
fluid chamber; a rotatable part comprising an annular member and a
moveable fluid port, the rotatable part being rotatably coupled to
the body with the annular member surrounding the body; and an
indexing feature defining a plurality of discrete angular positions
to which the rotatable part can be rotated with respect to the body
so as to alter the position of the moveable fluid port, wherein in
each of the angular positions the moveable fluid port is in fluid
communication with the fluid chamber. The body may have a generally
cylindrical outer wall portion through which the at least on fluid
passageway extends. The annular member may surround the cylindrical
outer wall portion with the moveable fluid port in fluid
communication with the fluid chamber through the at least one fluid
passageway. There may be at least two, at least four, at least six,
at least eight, or at least ten discrete angular positions. The
indexing feature may be integrally formed with the rotatable part
and the adapter body.
[0064] There may be multiple fluid passageways circumferentially
distributed about the body or cylindrical outer wall portion at
substantially the same axial position. The body or generally
cylindrical outer wall portion may have a stepped profile of
various diameters or may be of a constant diameter. The fluid port
may extend from the annular member in a direction having a radial
component. The annular member may be sealed to the body or
cylindrical outer wall portion axially either side of the at least
one fluid passageway. The fluid port may be in fluid communication
with the adapter chamber regardless of the angular position of the
rotatable part. Alternatively, the fluid port may only be in fluid
communication with the adapter chamber when it is in one of a set
number of angular positions.
[0065] The indexing feature may comprise a plurality of
circumferentially spaced first formations formed on either the body
or the rotatable part and at least one corresponding second
formation formed on the other of the body and the rotatable part.
The number of second formations may be the same as the number of
first formations and may be spaced in the same way. Alternatively,
there may be a single second formation and multiple first
formations. In one arrangement there are multiple first and second
formations that are both evenly circumferentially spaced with the
number of first formations an integer multiple of the number of
second formations. The first and/or second formations may be evenly
circumferentially distributed. First and second formations may be
arranged to engage with one another at each of the plurality
discrete angular positions. The first formations may comprise
recesses or projections and the at least one second formation
comprises the other of recesses or projections. The circumferential
spacing of the first formations may define the plurality of
discrete angular positions. First formations may be formed on
either the outer surface of the body, such as the cylindrical outer
wall portion of the body, or the inner surface of the annular
member. The at least one second formation may be formed on the
other of the outer surface of the body, such as the cylindrical
outer wall portion of the body, and the inner surface of the
annular member. The body, such as the cylindrical outer wall
portion of the body, or the annular member may be resiliently
deformable. This may allow the first and second formations to
engage, and be disengaged by relative rotation. The indexing
feature may inhibit the movement of the rotatable part away from a
particular discrete angular position. Movement of the rotatable
part away from a particular angular position may be achieved by
applying a sufficient rotation force between the adapter body and
the rotatable part.
[0066] The fluid coupling may further comprise an annular fluid
channel between the body and the annular member into which the
fluid port and the at least one fluid passageway opens so as to
ensure fluid communication between the fluid port and the fluid
chamber regardless of the angular position of the rotatable part.
The inner surface of the annular member and/or the outer surface of
the body, such as the cylindrical outer wall portion of the body,
may be provided with an annular fluid channel into which the fluid
port or the at least one fluid passageway opens. The annular fluid
channel may be aligned, such as axially aligned, so as to ensure
fluid communication between the fluid port and the fluid chamber
regardless of the angular position of the rotatable part. If there
are multiple fluid passageways they may all be aligned with the
annular fluid channel.
[0067] The fluid coupling may further comprise a sealing
arrangement sealing between the body and the annular member. The
sealing arrangement may comprise first and second seals disposed
either side of the at least one fluid passageway. The sealing
arrangement may comprise at least one lip seal having a lip portion
which seals against a sealing surface formed by either the body or
the annular member. The lip seal may comprise a main ring portion
integrally formed with the lip portion. The lip seal may be
annular. The lip seal may be mounted to the body or the annular
member. The lip portion may extend between the body and the annular
member. The lip portion may be resiliently deformable. The lip
portion may extend in a direction inclined to the radial direction.
The lip portion may extend in a direction that is inclined away
from the at least one fluid passageway. The lip portion may be
inclined in a direction away from the pressure side of the fluid
chamber. The lip seal may be configured such that a pressure within
the fluid chamber above a threshold causes the lip portion to
resiliently deflect away from the sealing surface, thereby allowing
gas within the fluid chamber to be vented out of the adapter
chamber. The lip seal may therefore provide the functionality of a
pressure relief valve.
[0068] The moveable fluid port may be an input port for supplying
fluid to the fluid chamber or an output port for delivering fluid
from the fluid chamber. The body may comprise a fluid coupling
inlet port and a fluid coupling outlet port at opposing ends.
[0069] The invention also relates to a manifold having a manifold
inlet port for a source of breathable gas and at least one manifold
outlet port for delivering breathable gas to a user, the manifold
comprising at least one fluid coupling in accordance with any
statement herein, wherein the manifold inlet port comprises a fluid
coupling inlet port and/or wherein the manifold outlet port
comprises the fluid coupling outlet port.
[0070] The invention also relates to breathing apparatus equipment
comprising the fluid coupling in accordance with any statement
herein or a manifold in accordance with any statement herein.
[0071] According to an aspect of the invention there is provided
breathing apparatus equipment, such as a waist mountable manifold,
comprising: a manifold having a manifold inlet port for a source of
breathable gas and at least one manifold outlet port for delivering
breathable gas to a user; a strap, such as a waist belt, arranged
to be worn by the user; and a holder coupled to the strap and
having a socket which is configured such that the manifold can be
removably located within the socket in multiple orientations. This
may result in a versatile piece of equipment which may be
configured by the particular user. For example, if the breathing
apparatus equipment is a waist mountable manifold, the user may
easily change the equipment from being suitable for wearing on
their left side, to being suitable for wearing on their right side.
This may be achieved by removing the manifold from the socket, and
relocating it in the same socket in a different orientation.
[0072] The manifold may be removably located within the socket in
one of the multiple orientations.
[0073] At least part of the socket may have a shape corresponding
to the external profile, or at least a substantial part of the
external profile, of the manifold. This allows the manifold to be
located within the socket, although part of the manifold, such as
any fittings or fluid ports, may project from the socket.
[0074] The holder may be arranged to protectively enclose the
manifold within the socket. Thus, when the manifold is located
within the socket the holder may protect it from damage.
[0075] The shape of the socket may be symmetrical. This may allow
the manifold to be located within the socket in multiple
orientations. The socket may be Y-shaped, such as a symmetrical
Y-shape. If the manifold is also a symmetrical Y-shape, the
manifold can be located within the socket in first and second
orientations that are essentially mirror images of each other. Of
course, it should be appreciated that shapes other than Y-shape
could be used. For example, the socket and/or manifold could be
X-shaped.
[0076] The socket may be provided in the rear side of the holder
such that in use the socket faces the user. This may mean that when
the manifold is located within the socket, in use, the manifold is
between the holder and user, thereby protecting the manifold from
being removed from the holder.
[0077] The equipment may further comprise retaining means
configured to retain the manifold within the socket. The socket may
comprises the retaining means. The retaining means may be resilient
such that the manifold snap-fits into the socket.
[0078] The external profile of the manifold, or at least a
substantial part of the external profile of the manifold, may be
symmetrical. The external profile of the manifold may be Y-shaped,
particularly, a symmetrical Y-shape. As explained above, other
shapes could be used, for example an X-shape. If the manifold is
Y-shaped having three branches, the lower branch may comprise the
manifold inlet port for a source of breathable gas, and the upper
two branches may each comprise a manifold outlet port, at least one
of them being a manifold outlet port for delivering breathable gas
to a user.
[0079] The front side of the holder may have a curved profile. The
holder may be integrally formed. The holder may be formed from a
plastics material, but other suitable materials may be used.
[0080] The holder may be slidably coupled to the strap such that it
can slide along at least a part of the length of the strap. The
strap may extend across the socket and/or may extend across the
rear side of the holder. The strap may be a waist belt, or a
shoulder strap, or a bandolier-style strap. The strap may be
continuous. The strap may be provided with length adjustment means
and/or a buckle allowing it to be fastened around a user.
[0081] The invention also relates to breathing apparatus
comprising: breathing apparatus equipment in accordance with any
statement herein; a breathable gas delivery device for delivering
breathable gas to a user with a first flexible conduit fluidically
coupled between the breathable gas delivery device and a manifold
outlet port; and a source of breathable gas with a second flexible
conduit fluidically coupled between the source of breathable gas
and the manifold inlet port.
[0082] The breathable gas delivery device may be a facemask, a hood
or a protection suit. The source of breathable gas may be a tank, a
cylinder, a compressor or a compressed air network (or ring main)
installed within a building.
[0083] The breathing apparatus may further comprise a clip fitted
to the first flexible conduit for securing the conduit to the user,
for example securing to a garment worn by the user.
[0084] The invention may comprise any combination of the features
and/or limitations referred to herein, except combinations of such
features as are mutually exclusive.
[0085] FIG. 1 shows compressed airline breathing apparatus 1
comprising breathing apparatus equipment, in the form of a waist
mountable manifold 10, a breathable gas delivery device 60,
comprising a facemask 62 and a lung demand valve (LDV) 64, and a
source of breathable gas, which in this embodiment is a cylinder of
compressed air 80. As will be described in detail below, the waist
mountable manifold 10 comprises a holder 20 attached to a waist
belt 14; the holder 20 holding a manifold 40 having a manifold
inlet port 42 and first and second manifold outlet ports 44, 46.
The manifold inlet port 42 of the manifold 40 is fluidically
coupled to the cylinder of compressed air 80 with a first flexible
hose 82 and one of the manifold outlet ports 44 of the manifold 40
is fluidically coupled to the LDV 64 with a second flexible hose
84. In use, the waist mountable manifold 10 is worn around a user's
waist and the facemask 62 is donned allowing the user to breathe
clean air supplied from the cylinder 80.
[0086] FIG. 2 shows the manifold 40 of the waist mountable manifold
10. The manifold 40 is essentially a fluid connector for receiving
and distributing breathable gas. The manifold 40 is substantially a
symmetrical Y-shape having a lower branch 41 and first and second
upper branches 43, 45. The manifold 40 is substantially symmetrical
about an axis A which extends through the centre of the lower
branch 42. The lower branch 41 is provided with a manifold inlet
port 42 which is threadedly attached to the lower branch 41, and
the first and second upper branches 43, 45 are provided with first
and second manifold outlet ports 44, 46. The manifold inlet port 42
is for fluidically connecting the manifold 40 to a source of
breathable gas 80, and the first manifold outlet port 44 is for
connection to a lung-demand valve (LDV) 64 which is attached to a
facemask 60. The second manifold outlet port 46 is for connection
to an auxiliary device. In the embodiment shown in FIG. 2, the
auxiliary device is a low-pressure warning device 70, such as an
alarm or whistle, that sounds when the pressure of the breathable
gas supplied to the manifold inlet port 42 falls below a minimum
threshold, such as 2.5 bar.
[0087] With reference to FIG. 3 the holder 20 is an integrally
formed component manufactured from a plastics material such as
fibre reinforced Nylon.RTM.. The holder 20 has a front side 22 that
in use faces away from the user and a rear side 24 that in use
faces towards the user. The front side of the holder 20 is curved
along its length and has a substantially smooth surface. As will be
described below, this reduces the risk of snagging. As shown in
FIG. 4, a socket 26 in the form of a cavity is provided on the rear
side 24 of the holder 20 such that in use it faces and is open
towards the user. The socket 26 is a substantially symmetrical
Y-shape and comprises a lower channel 28 and first and second upper
channels 30, 32. The socket 26 is substantially symmetrical shape
about an axis B which extends through the centre of the lower
channel 28. The shape of the socket 26 substantially corresponds to
the external profile of the manifold 40. Specifically, the socket
26 is shaped such that the lower and upper branches 41, 43, 45 of
the manifold 40 can be located within the lower and upper channels
28, 30, 32 of the socket 26. The lower channel 28 is provided with
snap-fit retaining lugs 34 for retaining the manifold 40 within the
socket 26. In particular, when the manifold 40 is located within
the socket 26, the opposing retaining lugs 34 grip the lower branch
41 of the manifold 40 and retain it within the socket 26. The
holder 20 is also provided with an elongate strap slot 18 at either
side of the socket 26 through which a strap or belt 14 can be
passed. This will be described in more detail below.
[0088] Referring back to FIG. 1, the waist belt 14 is an elongate
strap that can be worn around a user's waist. The waist belt 14
comprises male and female connectors 16 that allows the waist belt
14 to be fastened around the user's waist, and is provided with an
adjustment buckle (not shown) that allows the overall length of the
waist belt 14 to be varied so as to provide a comfortable fit. As
shown in FIG. 5, the waist belt 14 passes through the two strap
slots 18 in the holder 20 such that the belt 14 extends across the
rear side 24 of the holder 20 and across the socket 26. This
configuration allows the holder 20 to be slid along the length of
the belt 14.
[0089] As shown in FIG. 6, the manifold 40 is removably located
within the socket 26 of the holder 20. The lower branch 41 of the
manifold 40 is located within the lower channel 28 of the socket
26, and the first and second upper branches 43, 45 of the manifold
40 are located in the first and second upper channels 30, 32 of the
socket 26. With the manifold 40 located within the socket 26, the
manifold inlet and manifold outlet ports 42, 44, 46 project from
the holder 20. The manifold 40 snap-fits into the socket 26 and is
retained within the socket by the retaining lugs 34 which grip the
lower branch 41 of the manifold 40. The manifold 40 can be removed
from the socket 26 with ease without any tools by simply pulling
the manifold 40 away from the holder 20. This causes the retaining
lugs 34 to be resiliently deformed to allow the manifold 40 to be
removed from the socket 26.
[0090] Due to the shape of both the manifold 40 and the socket 26,
the manifold 40 can be located within the socket 26 in two
different orientations. In this particular embodiment this is
because the shape of the socket 26 corresponds to a substantial
part of the external profile of the manifold 40, and because the
socket 26 and manifold 40 are substantially symmetrical. This means
that the manifold 40 can be located in a first orientation (FIG. 7)
in which the first manifold outlet port 44 located on the left side
of the holder 20 as viewed from the front side, and in a second
orientation (FIG. 8) in which the first manifold outlet port 44 is
located on the right side of the holder 20 as viewed from the front
side. The benefits of being able to locate the manifold 40 within
the socket 26 in multiple orientations will be described in detail
below. It should be appreciated that in other embodiments the
socket and manifold may be configured differently in order to
achieve the ability of being able to locate the manifold within the
socket in multiple orientations.
[0091] In use, with the holder 20 slidably attached to the waist
belt 14 and a manifold 40 in the socket 26, the user secures the
belt 14 around his waist with the buckle 16. When worn, the front
curved profile 22 of the holder 20 faces away from the user and the
rear side 24 of the holder 20 provided with the socket 26 faces the
user. Since the belt 14 extends across the rear side 24 of the
holder 20, the manifold 40 is securely located between the holder
20 and the belt 14 (and the user's body). As the belt 14 is
tightened, the portion of the belt 14 extending across the socket
26 ensures that the manifold 40 is fully pushed into the socket 26.
If the manifold 40 is located within the socket 26 in the first
orientation as shown in FIG. 7, the holder 40 is moved along the
belt 14 so that it is located on the left side of the user's body.
In this position the first manifold outlet port 44 of the manifold
40 is angled forwards and the second manifold outlet port 46 is
angled rearwards.
[0092] The user then connects the first hose 82 between the LDV 64
attached to the facemask 62 and the first manifold outlet port 44
of the manifold 40, and connects the second hose 84 between the
cylinder of breathable gas 80 and the manifold inlet port 42. This
arrangement is shown in FIG. 1. The user then dons the facemask 62
and a valve (not shown) is opened so that breathable gas is
supplied to the user. If desired, a hose clip (not shown) can be
used to secure the first hose 82 to the user's garments. This may
reduce the risk of snagging.
[0093] The breathing apparatus 1 including the waist mountable
manifold 10 allows the user to work within an area of reduced or
contaminated air. The breathing apparatus 1 allows the user to move
around easily as the source of breathable gas is not worn by the
user. Further, the waist mountable manifold 10 ensures that the
hoses 82, 84 are kept close to the user's body which reduces any
snagging hazard. In addition to this, since the manifold 40 is
protectively housed in a holder 20 having a smooth front face 22
and is held against the user's body, any snagging risks are
minimised. Due to its low profile, the breathing equipment 1 is
particularly useful for work such as tank cleaning, painting,
welding or inspection in confined spaces where the atmosphere is
reduced and/or contaminated.
[0094] It has been described above that the manifold 40 is located
within the socket 26 in the first orientation (FIG. 7) and the
holder 20 is positioned on the left side of the user's body. In
this configuration the first hose 82 attaches to the manifold 40 on
the left side of the user's body, and the second hose 84 extends
from the left hip region of the user's body up to the facemask 62.
However, depending on the working conditions and equipment used, it
may be desirable to have the manifold on the right side of the
user's body so that the hoses 82, 84 are located on the right
side.
[0095] In order to reposition the manifold 40 on the opposite side
of the body, the belt 14 is loosened, and the manifold 40 is pulled
out of the socket 26 by hand. The holder 20 is then slid along the
length of the belt to the desired position, such as the right side
of the body, and the manifold 40 is pushed into the socket 26 in
the second orientation (FIG. 8). The belt 14 is then retightened
which ensures that the manifold 40 is fully pushed into the socket
26. As described above, in the second orientation, the first
manifold outlet port 44 to which the second hose 84 is attached is
angled forwards.
[0096] With the embodiment described above, repositioning the
manifold 40 can be achieved quickly and easily without any tools
and without disconnecting or doffing the breathing apparatus 1.
Thus, the manifold 40 and hoses 82, 84 can be repositioned during
use without having to leave the working environment.
[0097] As opposed to fitting a low pressure warning device 70 to
the second (or auxiliary) manifold outlet port 46, the manifold
outlet port 46 may be configured so that it is suitable for other
purposes. For example, it may be configured or suitable for use
with a second breathable gas delivery device (such as an LDV or a
constant flow device in which case it may be provided with a flow
control device), a compressed gas driven tool, a paint spray gun, a
ventilation vest, or a chemical protection suit.
[0098] As shown in FIG. 9, a banjo fitting 50 may be attached to
the inlet of the manifold 40 so as to provide a third manifold
outlet port 52. In order to attach the banjo fitting 50 the
manifold inlet port 42 is unscrewed from the lower branch 41 of the
manifold 40 and a different manifold inlet port 42 around which the
banjo fitting 50 is rotatably mounted is screwed into the lower
branch 41. The third manifold outlet port 52 of the banjo fitting
50 is in fluid communication with the manifold inlet port 42. The
third manifold outlet port 52 may be configured or suitable for use
with a compressed gas driven tool, a paint spray gun, a ventilation
vest, or a chemical protection suit, for example. The banjo fitting
50 may be rotated about an axis passing through the inlet port 42
so that the position of the third manifold outlet port 52 can be
changed. For example, if the orientation of the manifold 40 within
the socket 26 is changed so that the manifold 40 can be positioned
differently with respect to the user, it may be desirable to rotate
the banjo fitting 50 so that it is facing forwards.
[0099] It has been described that a substantial part of the
external profile of the manifold 40 is a symmetrical Y-shape and
that the socket 26 is a corresponding symmetrical Y shape. This
allows the manifold 40 to be located within the socket 26 in first
and second orientations that are mirror images of one another.
However, the ability to locate a manifold in a socket in multiple
orientations may be achieved with differently shaped manifolds
and/or sockets. For example, the socket could be Y-shaped and the
manifold could have a lower branch and a single upper branch
extending obliquely with respect to the lower branch. This would
allow the manifold to be located within the socket is first and
second orientations that are mirror images of one another. In
another example the socket could be a symmetrical X-shape and the
manifold could be a non-symmetrical Y-shape. The skilled person
should be able to appreciate other combinations of socket and
manifold shape that allow the manifold to be located within the
socket in multiple orientations.
[0100] Although it has been described above that the manifold has a
single manifold inlet port and first and second manifold outlet
ports, it should be appreciated that the manifold may have any
suitable number of manifold inlet and manifold outlet ports. For
example, the manifold could have a single manifold inlet port and
three manifold outlet ports, a single manifold inlet port and a
single manifold outlet port, or two manifold inlet ports and two
manifold outlet ports.
[0101] In the embodiment described above the holder is mounted on a
waist belt. However, it should be appreciated that in other
embodiments, the holder may be mounted on any belt or strap which
can be worn by the user. For example, the holder may be mounted or
attached to a shoulder strap or a bandolier-style strap.
[0102] In the foregoing embodiment it has been described that the
delivery device 60 is a facemask 62 provided with a LDV 64.
However, in other embodiments, the delivery device 60 may be a
constant flow hood or mask or protection suit, for example. As
shown in FIG. 10, in such an embodiment the manifold outlet port 44
to which the hood or mask is fluidically connected may be provided
with a valve assembly in the form of a gas control valve 100 which
both reduces the pressure of the breathable gas supplied at the
manifold inlet port 42, and regulates the flow rate.
[0103] As shown in FIG. 11, the gas control valve 100 comprises a
valve assembly housing 102 provided with a valve assembly inlet
port 104 at a lower end and a valve assembly outlet port 106 at an
upper end. The inlet port 104 is for receiving a source of
breathable gas and the outlet port 106 is for providing a constant
regulated flow of breathable gas to a user. Referring back to FIG.
10, the inlet port 104 can be fluidically and physically connected
to a manifold outlet port 44 such that the control valve 100 is
mounted to the manifold 40 and receives breathable gas supplied at
the manifold inlet port 42. A flexible conduit (not shown) can be
used to fluidically connect the outlet port 106 to a breathable gas
delivery device such as a hood (not shown) for supplying breathable
gas to a user.
[0104] The control valve 100 comprises a pressure reduction valve
108 (FIG. 12) which receives breathable gas from the inlet port 104
and reduces the pressure of it, and a separate flow control valve
110 (FIG. 12) downstream of the pressure reduction valve 108 which
receives reduced pressure breathable gas from the pressure
reduction valve 108 and delivers it from the outlet port 106 at a
controlled flow rate. The pressure reduction valve 108 and the flow
control valve 110 are both at least partly disposed within the same
housing 102. The flow control valve 110 comprises a flow adjuster
112 in the form of a rotatable knob disposed outside of the housing
102 which can be rotated to adjust the flow rate of the breathable
gas without altering the pressure at which it is supplied.
[0105] Referring now to FIG. 12, the pressure reduction valve 108
is sealed within the housing 102 by O-rings 114 and is disposed
towards the lower, upstream end of the housing 102. The pressure
reduction valve 108 comprises a pressure reduction valve inlet 114
at the upstream end of the pressure reduction valve 108 which is
arranged to receive breathable gas from the inlet port 104, and a
pressure chamber 118 at the downstream end of the pressure
reduction valve 108 which is arranged to supply reduced pressure
breathable gas to the flow control valve 110. Disposed between the
inlet 114 and the chamber (or outlet) 118 is a valve arrangement
comprising a valve seat 120, a valve member 122, a piston shaft
124, a piston 126 and a resilient biasing means 128 which are all
coaxial with one another and the general axial direction of the
control valve 100.
[0106] The valve inlet 114 is in the form of a bore formed in a
cylindrical wall 130 and the valve seat 120 is disposed within the
cylindrical wall 130 and is axially located below the valve inlet
114. The valve seat 120 is in the form of an elastomeric disc.
Slidably disposed within the cylindrical wall is the piston shaft
124, the lower tip of which forms the valve member 122 and the
upper end of which is attached to the piston 126 which is located
within the pressure chamber 118. The piston shaft 124 is hollow
along its entire length forming a fluid passageway 132 which passes
through the piston 126 and opens into the pressure chamber 118. The
resilient biasing means 128 acts between the housing 102 and the
piston 126 and biases the piston, piston shaft and valve member
upwards to an open position (FIG. 12) in which the valve member 122
is axially spaced away from the valve seat 120. In the open
position there is an open fluid passageway between the valve inlet
116 and the pressure chamber 118 as gas can flow between the valve
member 122 and the valve seat 120 and through the fluid passageway
132. As will be described in detail below, gas within the pressure
chamber 118 acts on the piston 126 to move it towards a closed
position (FIG. 13) in which the valve member 122 is seated on the
valve seat 120 thereby preventing flow through the pressure
reduction valve 108. The spring force of the resilient biasing
means 128 determines the pressure at which the pressure reduction
valve 108 closes (i.e. at what pressure the valve member 122
contacts the valve seat 120 thereby closing the fluid passageway).
The resilient biasing means 128 may be a spring, such as a coil
spring, or a mass of resiliently deformable material, for
example.
[0107] The flow control valve 110 is sealed within the housing 102
by O-rings 134 and is disposed towards the upper, downstream end of
the housing 102. The flow control valve 110 comprises a flow
control valve inlet 136 at the upstream end of the flow control
valve 110 which is in direct fluid communication with the pressure
chamber 118 and is arranged to receive reduced pressure breathable
gas therefrom, and a flow control valve outlet 138 which is
arranged to deliver reduced pressure breathable gas at a controlled
flow rate to the outlet port 106. Disposed within the housing 102
between the inlet and outlet 136, 138 is a lower plate member 140
and an upper plate member 142. The lower and upper plates 140, 142
are generally disc-like and are coaxially aligned with one another
and the general axial direction of the control valve. The lower and
upper plates 140, 142 lie on top of one another such that they
abut.
[0108] The lower plate 140 is rotabaly and axially fixed within the
housing 102 and comprises an annular wall portion 144 that extends
upwardly. The upper plate 142 has a diameter substantially the same
as the inner diameter of the annular wall portion 144 and is
located within the annular wall 144 such that it is sealed against
the lower plate 140. The upper plate 142 is rotatable with respect
to the lower plate 140 about the axis of the control valve 100. The
upper plate 142 is provided with a hole 146 within which a first
end of a pin 148 is located. The other end of the pin 148 is
located within a hole 150 provided in the flow adjuster knob 112
which is itself rotatably mounted to the housing 102 about the axis
of the control valve 100. Therefore, rotation of the flow adjuster
knob 112 causes the upper plate 142 to be rotated with respect to
the lower plate 140 within the housing 102. Stops (not shown) are
provided to limit the rotation of the flow adjuster knob 112
between maximum and minimum angular limits.
[0109] With additional reference to FIGS. 14 and 15, the lower and
upper plates 140, 142 are each provided with an orifice opening
152, 154 and a bypass opening 156, 158. The orifice openings 152,
154 are in the form of arcuate slots that are at the same radial
position and the bypass openings 156, 158 are in the form of
central openings that are coaxially aligned. As can be seen from
the Figures, since the bypass openings 156, 158 are coaxial with
one another, they are always aligned to the same extent regardless
of the relative rotational position of the lower and upper plates
140, 142. The bypass openings 156, 158 therefore form a bypass
passageway through the upper and lower plates 140, 142 of a fixed
size. However, since the orifice openings 152, 154 are arcuate, the
alignment between the slots can be adjusted between complete
alignment (FIG. 13), partial alignment (FIG. 14), and no alignment.
This variation can be achieved by rotating the upper plate 142
relative to the lower plate 140 using the flow adjuster knob 112.
Therefore, the orifice openings 152, 154 form a orifice passageway
through the lower and upper plates 140, 142 of a variable size.
Together, the orifice openings 152, 154 and the bypass openings
156, 158 provide a flow passageway through the lower and upper
plates 140, 142, the size of which can be varied between a fixed
minimum size (the size of the fixed bypass passageway) and a
maximum size (the size of the orifice passageway when the orifice
openings 152, 154 are in complete alignment and the fixed bypass
passageway). As will be described in detail below, the flow
adjuster know 112 can be rotated (thereby rotating the upper plate
142) to vary the size of the flow passageway so as to control the
flow rate of breathable gas delivered from the control device 100
without changing the pressure.
[0110] In use, the inlet port 104 of the control valve 100 is
attached to the manifold outlet port 44 and the outlet port 106 of
the control valve 100 is attached to a constant flow delivery
device, such as a hood, using a flexible conduit (not shown). The
manifold inlet port 42 is connected to a source of breathable gas,
such as a compressed air network (or ring main) installed within a
building, using another flexible conduit (not shown). The manifold
40 may be worn around a user's waist using the waist belt 14.
[0111] In this embodiment the supply pressure of the source of
breathable gas may be between 2.8 bar and 10 bar. This pressure is
received at the inlet port 104 and flows through the pressure
reduction valve inlet 116. The pressurised gas then flows under the
valve member 122 and through the flow passageway 132 into the
pressure chamber 118. The pressurised gas acts on the piston 126
and acts against the resilient biasing means 128 to move the
piston, piston shaft and valve member towards the closed position
(FIG. 13) in which the valve member 122 is engaged with the valve
seat 120. The spring force of the resilient biasing means 128 is
chosen to set the pressure delivered from the pressure reduction
valve 108 at a desired value P. Specifically, the spring force is
set so that when the pressure within the pressure chamber 118 is P,
the valve member 122 is seated on and engages the valve seat 120
preventing any gas flow through the pressure reduction valve 108.
In this embodiment the pressure value P is set at 2.5 bar. This
ensures that the pressure delivered from the pressure reduction
valve 108 is 2.5 bar. The breathable gas within the pressure
chamber 118 then flows through the flow control valve 110 to the
outlet port 106 and ultimately the hood. As the pressure within the
pressure chamber 118 reduces and falls below P, the spring force of
the resilient biasing means 128 moves the piston, piston shaft and
valve member to an open position (FIG. 12) in which the valve
member 122 is spaced away from the valve seat 120. This opens the
flow path and allows breathable gas to flow from the inlet 116 to
the pressure chamber 118. This causes the pressure to rise within
the pressure chamber 118 which closes the valve. This cycle repeats
continuously ensuring that the pressure of the breathable gas
within the pressure chamber 118 is at or about P. In reality, this
may mean that the piston, piston shaft and valve member "hover"
with the valve member 122 just above the valve seat 120.
[0112] The breathable gas within the pressure chamber 118 flows
through the flow control valve 110 to the outlet port 106 at a
controlled flow rate. The gas is allowed to flow through both the
orifice passageway defined by the orifice openings 152, 154 and the
bypass passageway defined by the bypass openings 156, 158. Since in
this embodiment the size of the bypass opening is fixed at a
minimum, it is not possible to completely shut-off the flow control
valve 110 and therefore the breathable gas is always supplied at a
minimum flow rate. The minimum flow rate is defined by the size of
the bypass opening and in this embodiment the minimum flow rate is
170 litres/minute. This may be the minimum safe flow rate of
breathable gas and therefore the bypass passageway may provide an
important safety feature. In order to increase or decrease (but
only to a minimum) the flow rate of the breathable gas supplied to
the hood, the flow adjuster knob 112 can be rotated causing the
degree of alignment of the orifice openings 152, 154 to change,
thereby altering the size of the orifice passageway. The degree of
alignment of the orifice openings 152, 154 can be altered between
complete alignment and no alignment. At complete (or maximum)
alignment the flow rate of the breathable gas is at a maximum which
in this embodiment is 350 litres/minute. At no alignment the
breathable gas only flows through the bypass passageway and the
flow rate is therefore 170 litres/minute.
[0113] An important feature of the control device 100 is that the
flow rate of the breathable gas delivered from the outlet port 106
is independent of the pressure supplied at the inlet port 104
within a specified range. The specified range of input pressure may
be between 2.8 bar and 10 bar, for example. This means that if the
supply pressure of the source of breathable gas changes, for
example if a number of additional users connect to the same ring
main, the flow rate of breathable gas delivered from the outlet
port 106 does not change. This may be important to ensure the
safety of the users. Further, altering the flow rate of the
breathable gas delivered from the outlet port 106 does not change
the pressure of the breathable gas delivered from the outlet port
106. These benefits result from the pressure reduction valve 108
and the flow control valve 110 being separate and independent from
one another, albeit housed in a common housing. In some known prior
art arrangements if the supply pressure drops, the flow rate
delivered drops automatically which may be undesirable or
hazardous. This significant disadvantage is overcome with the above
described arrangement.
[0114] Although it has been described that the control valve 100
can be attached to a manifold inlet port 44 of a manifold 40, it
should be appreciated that it could be used with other types of
breathing equipment and could be mounted on or to other
components.
[0115] If a constant flow breathable gas delivery device, such as a
mask or hood, is used it may be desirable for the user to be able
to inhale ambient air without removing the mask or hood. For
example, it may be desirable for the user to don the mask or hood
before commencing work and breathe ambient air, and then only
breathe pressurised breathable gas from a source of breathable gas,
such as a compressed air network (or ring main) installed within a
building, when they start work. This may preserve the source of
breathable gas; only using it when necessary.
[0116] FIG. 16 schematically shows an adapter 200 which may help
achieve the above objective. The adapter 200 comprises an adapter
body 202, an ambient air inlet port 204, a rotatable part 206
having a pressurised gas inlet port 208, a threaded adapter outlet
port 210 and a blanking plug 212. In use, the threaded adapter
outlet port 210 can be threadedly attached to the threaded gas
inlet port of a breathable gas delivery device, such as a hood or
mask, such that it is fluidically and physically coupled to the
delivery device. A pressurised source of breathable gas, such as
breathable gas from a compressed air network (or ring main) can be
fluidically connected to the pressurised gas inlet port 208 using a
flexible conduit (not shown). When the source of breathable gas is
turned on the user can inhale this through the adapter outlet port
210, but if the source of breathable gas is turned off, the user
can inhale ambient air through the ambient air inlet port 204 and
the adapter outlet port 210. If it is required to close off the
ambient air inlet port 204 completely, the blanking plug 212 can be
located within it.
[0117] Referring now to FIGS. 17 and 18, the adapter body 202 is
generally cylindrical and defines an adapter chamber 214. The first
end of the adapter body 202 is open and forms the ambient air inlet
204 which opens into the adapter chamber 214. The second opposing
end of the adapter body 202 is also open and opens into the adapter
chamber 214 and forms the adapter outlet port 210. The inner
surface of the adapter body 202 at the first end is threaded 216
and the blanking plug (FIG. 16) is threaded on an outer surface
such that it can be threaded into the ambient air inlet port 204 to
seal it. The outer surface of the second end of the adapter body
202 is also threaded and forms an adapter connector 218 which
allows the adapter 200 to be threadedly attached to a breathable
gas delivery device. Although generally cylindrical, the outer
surface of the adapter body 202 is provided with a number of
annular channels. One of the annular channels provides an annular
fluid channel 219 within which two fluid passageways 220 are
provided which are diametrically opposite and which extend through
the wall of the adapter body 202 into the adapter chamber 214. As
will be described in detail below, the pressurised gas inlet port
208 is in fluid communication with the adapter chamber 214 through
these passageways 220. In another of the annular channels a
plurality of, in this case 12, small recesses 222 are formed which
are circumferentially equally spaced around the adapter body 202.
As will be described in detail below, these small recesses 222 form
part of an indexing feature.
[0118] Disposed within the adapter chamber 214 is a filter 234 and
a one-way diaphragm valve 232. Both are disposed between the
ambient air inlet port 204 and the adapter chamber 214 and
therefore separate the ambient air inlet port 204 from both the
pressurised gas inlet port 208 and the adapter outlet port 210. The
filter 234 prevents any particulate from being inhaled into the
adapter chamber 214 and then out through the adapter outlet port
210. The one-way valve 236 permits the flow of air into the adapter
chamber 214 through the ambient air inlet port 204, but prevents
the flow of gas, such as pressurised gas supplied through the
pressurised gas inlet port 208, from exiting to the atmosphere
through the ambient air inlet port 204.
[0119] Referring now also to FIG. 19, the rotatable part 206
comprises an annular member 224 having an inner diameter comparable
to the outer diameter of the adapter body 202 and a stem 226 which
extends radially and slightly forward from the annular member 224.
The stem 226 is hollow along its entire length and forms a fluid
passageway 228 which is open at the inner surface on the annular
member 224. The end of the stem 226 is open and provides the
pressurised gas inlet port 208. The end of the stem 226 is also
provided with a connector 230 which allows a flexible conduit
carrying pressurised breathable gas to be connected to the
pressurised gas inlet port 208. On the inner surface of the annular
member 224 a plurality of, in this case six, small projections 232
are formed which are circumferentially and equally spaced around
the inner circumference. As will be described in detail below,
these cooperate with the small recesses 222 formed on the adapter
body 202 to provide an indexing feature.
[0120] Referring back to FIG. 17, the rotatable part 206 is
rotatably mounted to the adapter body 202 with the annular member
224 surrounding the generally cylindrical adapter body 202. Two
O-rings 233 are provided in annular channels to seal the annular
member 224 to the adapter body 202. The rotatable part 206 is
located such that the passageway 228 of the stem 226 is axially
aligned with the annular fluid channel 219 which ensures that the
pressurised gas inlet port 208 is in fluid communication with the
adapter chamber 214 through the fluid passageways 220 regardless of
the angular position of the rotatable part. Also, the rotatable
part 206 is located such that the recesses 222 formed in the outer
surface of the adapter body 202 are axially aligned with the
projections 232 formed on the inner surface of the annular member
224. The rotatable part 206 can be rotated to a plurality of, in
this case 12, discrete angular positions so as to change the
position of the stem 226 and pressurised gas inlet port 208 whilst
ensuring fluid communication between the pressurised gas inlet port
208 and the adapter chamber 214. The plurality of discrete angular
positions are defined by the angular spacing of the recesses 222
and at each position the six projections 232 engage with six of the
12 recesses 222. The engagement of the recesses 222 and projections
232 inhibit the rotational movement of the rotatable part 206 away
from that angular position. However, by applying a sufficiently
large rotational force one or both of the parts resiliently deform,
causing the projections 232 and recesses 222 to disengage allowing
the rotatable part 206 to be rotated to a different angular
position. This indexing feature allows the rotatable part 206 to be
temporarily locked in one of a number of angular positions whilst
allowing the angular position of the rotatable part to be easily
adjusted.
[0121] In use, the adapter 200 is connected to a breathable gas
delivery device, such as a mask, with the adapter connector 230
threaded into the gas inlet port of the mask. This ensures fluid
communication between the adapter outlet port 210 and the gas inlet
port of the mask. A pressurised source of breathable gas, such as a
compressed air network (or ring main), is connected to the
pressurised gas inlet port 208 of the adapter 200 using a flexible
conduit. The flexible conduit may be fluidically connected to a
manifold outlet port 44, and may be connected to the outlet port
104 of the control valve assembly 100. Before turning on the source
of breathable gas, the user can inhale ambient air through the
ambient air inlet port 204. As shown in FIG. 20, if the option of
breathing ambient air is not required, or is indeed hazardous, the
blanking plug 212 can be threaded into the ambient air inlet port
204 to seal it.
[0122] As shown in FIG. 21, for comfort and safety reasons, the
angular position of the pressurised gas inlet port 208 can be
adjusted by rotating the rotatable part 206 with respect to the
adapter body 202. The indexing feature comprising the recesses 222
and projections 232 define a discrete number of angular positions,
but the adapter 200 is configured to ensure that the pressurised
gas inlet port 208 is always in fluid communication with the
adapter chamber 214 regardless of the angular position of the
rotatable part 206.
[0123] When it is desired to breathe pressurised gas from the
source of breathable gas, the supply can be turned on. It may be
possible to turn on the source of breathable gas such that
pressurised gas is continuously supplied to the pressurised gas
inlet port 208 at a fixed pressure, such as 2.5 bar, and at a flow
rate of between 170 litres/minute and 350 litres/minute, for
example. The pressurised gas flows through the pressurised gas
inlet port 208, through the passageway 228 in the stem 226 and into
the annular fluid channel 219 formed in the adapter body 202. The
gas then flows through the passageways 220 in the adapter body 202
and into the adapter chamber 214 where it can be inhaled through
the adapter outlet port 210. The pressurised gas is above
atmospheric pressure and therefore acts on the one-way diaphragm
valve 236 to keep it in a closed position. This prevents the
supplied pressurised gas from exiting through the ambient air inlet
port 204, and also ensures that no ambient air can be inhaled
through the ambient air inlet port 204. This may be particularly
important if the ambient atmosphere is contaminated.
[0124] FIG. 22 shows a second alternative embodiment of the adapter
200 in which an excess flow passageway 238 is provided that extends
through the adapter body 202 and opens into the adapter chamber 214
downstream from the filter 234 and valve 236. Disposed within the
excess flow passageway 238 is a one-way diaphragm excess flow valve
240. In use, if the pressure within the adapter chamber 214 and the
mask (or hood) is too great then the excess flow valve 240 will
open causing excess pressurised gas to vent to the atmosphere.
Although excess gas can typically vent to the atmosphere through
the mask or hood, if the gas flow rate is particularly high, when
the user exhales the excess gas will not be able to be vented
through the mask or hood. Therefore, the adapter 200 provides this
beneficial feature.
[0125] FIG. 23 schematically shows a third embodiment of the
adapter 200 which is similar to the first and second embodiments.
As for the first and second embodiments, the adapter 200 comprises
an adapter body 202, an ambient air inlet port 204, a rotatable
part 206 having a pressurised gas inlet port 208, a threaded
adapter outlet port 210 and a blanking plug 212.
[0126] Referring now to FIGS. 24 and 25, as for the first and
second embodiments, the adapter body 202 is generally cylindrical
and defines an adapter chamber 214. The first and second ends of
the adapter body 202 are open and form the ambient air inlet 204
and adapter outlet port 210 respectively. The inner surface of the
adapter body 202 at the first end is threaded 216 for cooperation
with the threaded blanking plug 212, and the outer surface of the
second end of the adapter body 202 is also threaded and forms an
adapter connector 218 which allows the adapter 200 to be threadedly
attached to a breathable gas delivery device. The outer surface of
the adapter body 202 is provided with an annular fluid channel 219
within which four fluid passageways 220 are provided which are
uniformly circumferentially spaced around the annular channel 219.
The passageways 220 are in the form of elongate holes which extend
through the wall of the adapter body 202 into the adapter chamber
214. A second annular channel is provided within which two
diametrically opposite projections 223 are provided. These
projections 223 form part of an indexing feature. As for the first
and second embodiment, disposed within the adapter chamber 214 is a
filter 234 and a one-way diaphragm valve 232 disposed between the
ambient air inlet port 204 and the adapter chamber 214.
[0127] Referring now also to FIG. 26, the rotatable part 206
comprises an annular member 224 having an inner diameter comparable
to the outer diameter of the adapter body 202 and a socket body 226
which extends away from the annular member 224 in a direction that
is perpendicular to the centreline of the annular member 224 and
offset from it. The socket body 226 is hollow and forms a fluid
passageway which is open at the inner surface on the annular member
224. The end of the socket body 226 is open and provides the
pressurised gas inlet port 208. A flexible conduit carrying
pressurised breathable gas can be secured within the socket body
226. The end of the annular member 224 is provided with a plurality
of, in this case 18, teeth 231 which are circumferentially and
equally spaced such that there is a gap 235 (or recess) between
adjacent teeth. Each tooth 231 (with the exception of every sixth
tooth) comprises an inwardly extending radial projection 231a. The
teeth 231 cooperate with the projections 223 formed on the adapter
body 202 to provide an indexing feature.
[0128] Referring back to FIG. 24, the rotatable part 206 is
rotatably mounted to the adapter body 202 with the annular member
224 surrounding the generally cylindrical adapter body 202. The
rotatable part 206 is located such that the passageway of the
socket body 226 is axially aligned with the annular fluid channel
219 which ensures that the pressurised gas inlet port 208 is in
fluid communication with the adapter chamber 214 through the fluid
passageways 220 regardless of the angular position of the rotatable
part. Also, the rotatable part 206 is located such that the two
projections 223 formed in the outer surface of the adapter body 202
are axially aligned with the teeth projections 231a of the annular
member 224. The rotatable part 206 can be rotated to a plurality
of, in this case 18, discrete angular positions so as to change the
position of the pressurised gas inlet port 208, whilst ensuring
fluid communication between the pressurised gas inlet port 208 and
the adapter chamber 214. The plurality of discrete angular
positions are defined by the angular spacing of the teeth 231. At
each discrete angular position at least one of the projections 223
is disposed within the gap 235 between the teeth projections 231a
of adjacent teeth 231. The gaps (or recesses) 235 between the teeth
231 therefore engage with the projections 223 to inhibit the
rotational movement of the rotatable part 206 away from that
angular position. However, by applying a sufficiently large
rotational force, at least one tooth 231 resiliently deforms
radially outwardly, thereby allowing the tooth projection 231a to
ride over the projections 223. This indexing feature allows the
rotatable part 206 to be temporarily locked in one of a number of
angular positions, whilst allowing the angular position of the
rotatable part 206 to be easily adjusted.
[0129] As for the first and second embodiments, in use, the adapter
200 is connected to a breathable gas delivery device, such as a
mask, with the adapter connector 230 threaded into the gas inlet
port of the mask. A pressurised source of breathable gas, such as a
compressed air network (or ring main), is connected to the
pressurised gas inlet port 208 of the adapter 200 using a flexible
conduit. Before turning on the source of breathable gas, the user
can inhale ambient air through the ambient air inlet port 204. As
shown in FIG. 27, for comfort and safety reasons, the angular
position of the pressurised gas inlet port 208 can be adjusted by
rotating the rotatable part 206 with respect to the adapter body
202. The indexing feature comprising the teeth 231 defining the
gaps/recesses 235 and the projections 223 define a discrete number
of angular positions.
[0130] As best shown in FIG. 28, the adapter 200 is provided with a
sealing arrangement for sealing between the adapter body 202 and
the annular member 224 of the rotatable part 206. The sealing
arrangement comprises an annular lip seal 242 and an o-ring 244
that are disposed between the adapter body 202 and the annular
member 224. In other embodiments both seals 242, 244 could be lip
seals. The seals 242, 244 are located in respective annular grooves
or channels 246, 248 provided in the other surface of the adapter
body 202. In other embodiments, the seals 242, 244 could be located
in grooves or channels formed in the inner surface of the annular
member 224. The seals 242, 244 are located either side of the fluid
passageways 220 and the annular fluid channel 219. The sealing
arrangement therefore allows the rotatable part 206 to be rotated
with respect to the adapter body 202, whilst ensuring fluid
communication between the annular fluid channel 219 and the adapter
chamber 214, but preventing undesirable fluid leakage from between
the two components 202, 224.
[0131] The lip seal 242 is integrally formed from a resilient
material such as a synthetic rubber and comprises a main ring
portion 250 and a lip portion 252. The lip portion 252 extends away
from the main ring portion 250 in a direction L that is inclined
(oblique) to the radial direction R and the axial direction A. The
direction of extent of the lip portion 252 therefore has both a
radial and an axial component. The lip seal 242 is mounted to the
adapter body 202 with the main ring portion 250 disposed in the
annular groove 246 such that the lip portion 252 extends in a
direction L that is away from the fluid passageway 220 and the
annular fluid channel 219. It therefore extends in a direction L
away from the pressure side (i.e. the axial component of the
direction of extent is away from the pressure side). The outer tip
of the lip portion 252 abuts or seals against a sealing surface 254
which in this embodiment is the inner surface of the annular member
224. The o-ring 244 also seals against this sealing surface
244.
[0132] Advantageously, in this embodiment, the sealing arrangement
provides the functionality of an excess flow valve. In use, exhaled
or excess gas is typically vented to the atmosphere through the
mask or hood. However, if the pressurised gas flow rate is
particularly high, when the user exhales, not all of the excess gas
is able to be vented through the mask or hood. As shown in FIG. 29,
if the pressure within the adapter chamber 214 and the mask (or
hood) is too great, the pressure acts of the inner surface of the
lip portion 252 of the lip seal 242 to resiliently deflect it
(towards the axial direction) so that the tip of the lip portion
252 moves away from the sealing surface 254. This forms an excess
flow passageway 256 between the lip seal 242 and the sealing
surface 254. This allows excess gas within the adapter chamber 214
to vent to the atmosphere between the tip of the lip portion 252
and the sealing surface 254. When the pressure within the adapter
chamber 214 drops again, the lip portion 252 moves back such that
the tip of the lip portion 252 once again seals against the sealing
surface 254. The lip seal 242 also prevents gas flowing into the
adapter chamber 214 from the outside. For example, if the gas
pressure outside the adapter chamber 214 is greater than the
pressure within the adapter chamber 214, the pressure acts on the
outside surface of the lip portion 252 which pushes the tip of the
lip portion 252 against the sealing surface 254. The improves the
seal provided by the sealing arrangement.
[0133] Although it has been described that the adapter 200 could be
used with the manifold 40 and/or the control valve 100, it should
be appreciated that it could be used with any source of pressurised
breathable gas.
[0134] Further, the indexing feature provided between the adapter
body 202 and the rotatable part 206 could be used with any
rotatable fluid coupling (such as banjo fittings) in order to
provide indexing. For example, the banjo fitting of FIG. 9 could be
provided with the indexing feature of the adapter 200 such that it
can be rotated to a plurality of discrete angular positions. Of
course it should also be appreciated that the adapter 200 need not
necessarily be provided with an indexing feature, or indeed the
position of the pressurised gas inlet port could be fixed.
[0135] Although it has been described that the source of breathable
gas is a cylinder of compressed air, it will be appreciated that in
other embodiments the source of breathable gas may be a compressed
air network (or ring main) installed within a building, or a large
tank of compressed air, for example.
[0136] Although the invention has been described in terms of
exemplary embodiments, it is not limited thereto. Rather, the
appended claims should be construed broadly to include other
variants and embodiments of the invention which may be made by
those skilled in the art without departing from the scope and range
of equivalents of the invention. This disclosure is intended to
cover any adaptations or variations of the embodiments discussed
herein.
* * * * *