Fluid handling – With indicator – register – recorder – alarm or inspection means – Fluid pressure responsive indicator – recorder or alarm
Reexamination Certificate
2000-03-10
2001-08-14
Lee, Kevin (Department: 3753)
Fluid handling
With indicator, register, recorder, alarm or inspection means
Fluid pressure responsive indicator, recorder or alarm
C137S505250, C116S070000
Reexamination Certificate
active
06273130
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to a gas regulator/valve device, particularly for use with breathing apparatus.
Known breathing apparatus generally comprises a source of breathable gas, such as a cylinder of compressed air, some form of hood or mask which is placed over the user's face or head and a tube connecting the two to supply gas from the source to the hood or mask. Generally speaking, the source of gas will be under a higher pressure than is necessary for supply to the user, and a regulator is used at the output of the gas source to reduce the pressure from that of the cylinder to that required by the user. Finally some form of valve is used to allow the supply to be turned on and off.
As the gas cylinder empties, the high pressure within the cylinder gradually falls until the pressure within the cylinder is no greater than the output pressure from the regulator. At this point, the cylinder can be considered to be virtually empty, and requires charging. In certain applications, it is useful to provide a warning to the user that the cylinder is near-empty, or to initiate some automatic process for charging cylinders. For example in emergency escape breathing apparatus, the user has a very limited supply of gas, usually from just a single cylinder, so there is no question of changing the cylinder and carrying on. Rather, the purpose of such equipment is to allow the user, after donning the equipment, to escape to safety from a dangerous situation. In such circumstances, it may be vital to know that the cylinder is running out.
It is known, in these circumstances, to provide an audible warning, this typically being in the form of a whistle actuated by the gas supply. Such whistles are generally connected to the cylinder side of the regulator and thus monitor the high cylinder pressure. Means are provided, within the whistle body, for detecting when the cylinder pressure falls to a predetermined level, at which point a valve is opened to actuate the whistle by means of the remaining gas pressure. Such whistles are complicated and expensive.
Known regulators comprise a piston which is movable within a cylindrical bore and controls flow through an orifice at the output from the cylinder to regulate the supply from the cylinder.
SUMMARY
According to a first aspect of the present invention, means are provided for monitoring the movement of said piston and providing an output when the piston reaches a predetermined position within the cylindrical bore, said position being indicative that the source of gas is empty or near-empty.
In a regulator utilising a piston, such as described above, the regulated output pressure is generally set by means of a spring which acts on the piston. It is a characteristic of such regulators that, as the pressure of the source gradually falls, so the piston slowly moves away from an arbitrary datum position, thus allowing the aforesaid valve to open wider and wider as the pressure falls. This movement is slight during the initial stages of discharging the gas source but, as the pressure of the gas source falls to a level approaching that of the regulated output of the valve, the movement markedly increases, causing an almost step movement in the movement of the piston. Once the piston has undertaken this step movement, regulation effectively ceases and the output pressure falls with the source pressure until the source is empty. The monitoring means of the present invention detects the step movement to enable a signal of some sort to be generated to indicate that the pressure of the source has fallen to substantially the same level as the regulated output pressure and that regulation has, in effect, ceased.
The monitoring means can take various forms, for example a magneto detector, a hall-effect sensor or a proximity sensor, all of which will provide an electric signal which can be used to initiate some automatic process or activate an alarm, or both. In an embodiment of the invention the piston itself acts as a valve member which, at a predetermined position of the piston, opens a valve to allow pressure to be applied to a transducer, which in turn generates an electrical signal in the manner described above, or direct to a pressure operated alarm, or whistle. For example, said monitoring means may comprise a port opening into the wall of the bore, and which is exposed to the input flow of gas when the piston reaches said predetermined position within the bore.
In certain applications, for example in emergency escape breathing equipment, it is necessary that the valve associated with the cylinder be difficult or impossible to close, once it has been opened. In emergency escape equipment, for example, it would clearly be undesirable to have the situation in which it was possible to use the cylinder for just short lengths of time and then leaving the equipment in a partially discharged state with no indication that the amount of gas remaining in the cylinder is less than would be expected.
In a second aspect of the present invention, such a valve is presented. In particular the invention provides a valve assembly for a regulator, said assembly comprising a cylindrical member which is slidably movable in a bore in a valve body, said bore extending from the outlet side of said regulator, and a valve for controlling the flow of gas from the output of said regulator, said cylindrical member being movable from a first position in which said valve is closed to a second position in which it is open, and the arrangement being such that the pressure of gas at the output to said regulator acts on said cylindrical member in such a way as to bias said member towards said second position and wherein means are provided for locking the cylindrical member in said first position against said bias.
The valve is operated by releasing the locking means, thus allowing the cylindrical member to move under the pressure of gas, thus opening the valve.
Subsequent closure of the valve can only be achieved by moving the cylindrical member back to the first position against the pressure of gas at the regulator output and re-applying the latching means.
The locking means may cheaply and conveniently take the form of a pin which extends across the aforesaid bore and prevents passage of the cylindrical member. Because of the bias felt by the cylindrical member and transferred to the pin, the pin will maintain its position without falling out. When the gas is needed, the pin can be pulled out, thus allowing the cylindrical member to move to the second position, thus opening the valve and allowing the regulator to start taking gas from the source.
In an emergency escape breathing apparatus, or similar application, the pin, or other latching means, can be automatically actuated by some external action such as the opening of the bag containing the equipment. A short length of cord attached at one end to the pin and at the other end to the lid of the bag can be arranged so that, as the lid is opened, the pin is automatically rewound, thus switching on the gas supply.
REFERENCES:
patent: 3785333 (1974-01-01), Warncke et al.
patent: 3811400 (1974-05-01), Smilg
patent: 1082126 (1960-05-01), None
patent: 2672221 (1992-08-01), None
Lee Kevin
Protector Technologies B.V.
Volpe and Koenig P.C.
LandOfFree
Gas regulator/valve device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Gas regulator/valve device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Gas regulator/valve device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2547121