The present invention relates to a breathing gas system or a “walk around bottle” system, for use in aircraft.
The use of breathing gas systems on aircraft is known. It has been known to provide breathing gas systems with fixed output flow rates. Many of the systems are supplied with multiple outlets, each outlet being preset to deliver a different flow rate.
There is a need for a breathing gas dispenser with selectable output flow rates that relies on flow control by calibrated orifice.
The present invention meets the above-described need by providing a breathing gas dispenser with selectable output flow rates. The dispenser includes a vessel containing a supply of breathable gas at storage pressure. The vessel is in fluid communication with a regulator assembly. The regulator assembly is capable of reducing the pressure of the gas to a delivery pressure in a chamber. The chamber has an outlet. A plate is disposed in the chamber. The plate has a plurality of openings defined therein. The openings are disposed in pairs comprising a first opening and a second opening. The first or second opening or both may contain an orifice housing with a precision metering orifice defined therein. A flow selector is capable of causing the plate to rotate such that each of the pairs of openings are sequentially brought into registry with the outlet such that a user can select an output flow rate.
The invention is illustrated in the drawings in which like reference characters designate the same or similar parts throughout the figures of which:
Referring to
The pressure vessel 10 may be manufactured of a composite material such as an aluminum liner with a carbon fiber over-wrap and an epoxy resin finish as will be evident to those of ordinary skill in the art. The vessel 10 may have a nominal volume up to 140 cubic inches and may store breathing gas at pressures up to 1850 p.s.i.g. (hereinafter referred to as “storage pressure”).
As will also be evident to those of ordinary skill in the art based on this disclosure, the pressure vessel 10 is typically provided with a high pressure relief valve 13, a high pressure fill valve 16, an indicating gauge 19 and a filter 22. The high pressure relief valve 13 may be of a frangible disc type. The high pressure fill valve 16 is a normally closed check valve. Application of a pressure higher than the storage pressure will cause the check valve to open and the storage pressure can be replenished. The indicating gauge 19 may be of a direct drive type. The filter 22 captures particles that may be generated by the mechanical interaction of the upstream components prior to reaching the regulator inlet.
When an on-off valve 25 is opened, gas flow is allowed to pass to the inlet passage 26 (
A flow selector 33 provides for switching between precise metering rates and is coupled to the control knob 50 for the on/off valve 25 as indicated by dashed lines 36.
Turning to
A control knob 50 (
In
Turning to
Turning of the knob 50 opens the on/off valve 25 through rotation of shaft 60. As described above, the knob 50 is also coupled to the indexer 43 by means of the engagement of the face gears 53 attached to the knob 50 with pinion 56 attached to or formed integrally with the indexer 43. Accordingly, turning of the knob 50 also causes an orifice plate 70 retained by the indexer 43 to rotate. Rotation of the orifice plate 70 causes the flow setting to switch. When the indexer 43 rotates, it repositions the orifice plate 70 to allow multiple flow rates. The visual indicator 37 located on the outside surface of the indexer 43 indicates the flow setting (i.e., in the example shown, there are three positions: off, “2” or “4” liters per minute). The visual indicator 37 aligns with a window (not shown) in the protective cover 75.
In
As shown in
When the passageway 100 is pressurized with a fixed regulated pressure, flow passes along the flow path indicated by arrows 87 down the passageway 100 and into the through hole 86 in the orifice plate 70. Next, the flow enters the cavity 92 in the plate 70 and then exits the cavity 92 through the precisely calibrated orifice 83 back up through a second passageway 111 where it is communicated to the outlet 120 for the user.
The passageway 100 through the low pressure body 69 is fixed such that rotation of the indexer 43 successively brings each pair of openings in the orifice plate 70 into registry with the passageways. The quad ring seals 106 provide the necessary seals at the interface between the passageway 100 and the through hole 86 in the orifice plate and between the calibrated orifice 83 and the second passageway 111.
Turning to
In
Referring to
As will also be evident to those of ordinary skill in the art based on this disclosure, the pressure vessel 210 is typically provided with a high pressure relief valve 213, a high pressure fill valve 216, an indicating gauge 219 and a filter 222. The high pressure relief valve 213 may be of a frangible disc type. The high pressure fill valve 216 is a normally closed check valve. Application of a pressure higher than the storage pressure will cause the check valve to open and the storage pressure can be replenished. The indicating gauge 219 may be of a direct drive type. The filter 222 captures particles that may be generated by the mechanical interaction of the upstream components prior to reaching the regulator inlet.
When an on-off valve 225 is opened, gas flow is allowed to pass to the inlet passage of a regulator 228. The regulator 228 accepts any pressure between 150 and 1850 p.s.i.g. and reduces it to approximately 55 p.s.i.g. A resetting low pressure relief valve 131 is connected to the regulator. The low pressure relief valve 231 opens between 90 and 135 p.s.i.g. to vent pressure in the event of a regulator malfunction such as leakage past the regulating seat (not shown) of regulator 228 in a no flow condition or other condition causing excess pressure. This valve 231 protects low pressure components from being over pressurized. The low pressure relief valve 231 will reset automatically when the regulated pressure returns to normal levels.
As shown in the diagram, the regulator 228 is provided with an outlet position (“Port 1”) capable of receiving a flow selector 234 of the present invention. Accordingly, Port 1 designates a fitting on the regulator 228 that is capable of receiving the flow selector 234 of the present invention. As will be described in greater detail below, the flow selector 234 receives regulated pressure from the pressure regulator 228, meters it to a user selected flow rate and allows it to pass into one or more outlets for user connected devices such as breathing masks (not shown).
Turning to
The regulated pressure travels through the passageway 240 through the flow selector 234 until it pressurizes the cavity 264 of the selector body 243 containing the cylinder 246. The cylinder 246 has multiple chambers 267 disposed around its circumference. When the chambers 267 are rotated about an axis of rotation 270, each chamber 267 rotates sequentially into alignment with a passageway 273 defined in the selector body 243 at an offset from the longitudinal axis 274 of the selector body 243. The chambers 267 are capable of receiving calibrated orifices 276 of specific flow rate. The metering orifices 276 are precisely machined parts that are pre-calibrated such that they will provide specific flow rates at predetermined pressure differentials. Accordingly, the system of the present invention does not have to be calibrated for flow when the calibrated orifices 276 are installed or changed.
By way of example only, the embodiment shown has six chambers 267 with two chambers containing metering orifices 276 (best shown in
The seal nut 249 attaches the cylinder 246 to the selector body 243. O-ring 268 between the cylinder 246 and the seal nut 249 and O-ring 269 between the seal nut 249 and the selector body 243 prevent the regulated pressure from escaping to atmosphere.
A quad ring 270 seals the interface between the metered orifice 276 and passageway 273 inside the selector body 243 to prevent the regulated pressure from leaking into the passageway 280 formed by intersecting drills 283 and 286 in selector body 243.
The pressure above or upstream of the metering orifice 276 is the regulated pressure, and the pressure below or downstream of the orifice 276 is communicated to the cavity 261 inside Port 1. When Port 1 of the regulator 228 is configured with the flow selector 234 of the present invention, the output of the flow selector is directed to Port 2 as shown in
Port 3 may be connected to breathing masks (not shown) or other devices. Port 3 may be provided with a check valve 288. When the check valve 288 of the outlet in Port 3 is opened, all the ports are exposed to ambient pressure. Therefore, the pressure below the metering orifice 276 is atmospheric pressure. The pressure differential above and below the metering orifice 276 will cause the gas to flow through the orifice 276. The metering orifice 276 is sized so that the differential pressure provides a specific user requested flow rate. The gas flow follows the path 237 indicated by the heavy line 237 into cavity 261 in Port 1, to Port 2, and out to the user through Port 3.
Turning to
The user rotates the knob 290 to align different orifices 276 within the cylinder 246 with the flow path to the user. Accordingly, the user can select from multiple different flow rates (up to six different flow rates in this example). One of the positions in cylinder 246 may be configured to provide a no-flow position by means of a closed chamber 267 (as shown on the left side of
The specific flow rates associated with the orifices 276 loaded into the cylinder 246 may be printed on the cylindrical surface 299 of the knob 290. The flow rate of the orifice 276 that is aligned to flow gas to the user can be seen on the surface of knob 290 through a window 291 on the seal nut 249. This indicator notifies the user of and allows him to select the desired flow rate. The knob 290 and cylinder 246 may be detented in various ways as will be evident to those of ordinary skill in the art to provide an indication when a specific orifice is aligned for a specific flow rate. For example, a spring (i.e., ball and spring arrangement) may be used to provide a torque threshold that must be exceeded in order to rotate the cylinder 146 to another orifice 276. Also, a positive locking mechanism with a release button could also be used.
The flow selector 234 of the present invention may be disposed in fluid communication with a single outlet leading to a breathing mask as described above. The flow selector 234 of the present invention may also be disposed in fluid communication with more than one outlet connected in parallel. As a result the flow selector 234 of the present invention can be used to simultaneously feed multiple outlets. If the outlets are connected to masks or other devices having similar resistance, then the gas flow will divide substantially equally between the outlets.
While the invention has been described in connection with certain embodiments, it is not intended to limit the scope of the invention to the particular forms set forth, but, on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention. Also, the shapes of some of the components may vary due to weight reduction considerations. For instance, depending on the number of different calibrated orifices required, the indexer and orifice plate could be oval-shaped, or clover-shaped or the like.
This application claims the benefit of U.S. Provisional Patent Application Nos. 60/550,247 filed Mar. 4, 2004, and 60/564,511 filed Apr. 22, 2004.
Number | Date | Country | |
---|---|---|---|
60550247 | Mar 2004 | US | |
60564511 | Apr 2004 | US |