Abstract:
A Self-Contained Breathing Apparatus (SCBA) regulator is tested using a breath simulator having (i) a cup-shaped housing defining an interior volume and an open end, and (ii) an empty syringe with a plunger disposed therein and terminating in a dispensing tip coupled to the housing for sealed fluid communication with the interior volume thereof.

Description:
ORIGIN OF THE INVENTION 
     The invention described herein was made in the performance of official duties by an employee of the Department of the Navy and may be manufactured, used, licensed by or for the Government for any governmental purpose without payment of any royalties thereon. 
    
    
     FIELD OF THE INVENTION 
     The invention relates generally to testing regulators, and more particularly to a sanitary testing system for a Self-Contained Breathing Apparatus (SCBA) regulator that improves the efficiency of periodic regulator testing operations. 
     BACKGROUND OF THE INVENTION 
     Firefighting and “hazmat” breathing systems typically include a “Self-Contained Breathing Apparatus” (SCBA) regulator that must be periodically tested to assure proper operation. For example, the Navy&#39;s required period for testing is every month. Currently, the test is performed by an operator that connects the regulator to a breathing system&#39;s face piece. The operator then dons the face piece and breathes in and out to test the regulator&#39;s operation. Once this task is completed, the operator must sanitize the regulator by washing and then drying the regulator. This process is tedious and time-consuming, especially when there are a substantial number of regulators that must be tested every month. For example, a Navy aircraft carrier has approximately 400 regulators that must undergo monthly, testing. The current regulator testing procedures require about 0.3 man-hours for an operational check and sanitizing procedure. Thus, on an annual basis, nearly 1500 man-hours are required to perform this operation for one Navy carrier. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide a system and method for testing the operation of a SCBA regulator. 
     Another object of the present invention is to provide a system and method that reduces the amount of time that it takes to test the operation of a SCBA regulator. 
     Other objects and advantages of the present invention will become more obvious hereinafter in the specification and drawings. 
     In accordance with the present invention, a system and method of testing a Self-Contained Breathing Apparatus (SCBA) regulator are provided. The system is a breath simulator having (i) a cup-shaped housing defining an interior volume and an open end, and (ii) an empty syringe with a plunger disposed therein and terminating in a dispensing tip coupled to the housing for sealed fluid communication with the interior volume thereof. The open end of the breath simulator is coupled to the face piece of a SCBA regulator. The plunger is retracted to generate a vacuum pressure indicative of inhalation. The plunger is then depressed to generate a positive pressure indicative of exhalation. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other objects, features and advantages of the present invention will become apparent upon reference to the following description of the preferred embodiments and to the drawings, wherein corresponding reference characters indicate corresponding parts throughout the several views of the drawings and wherein: 
         FIG. 1  is a perspective view of a SCBA regulator testing system in accordance with an embodiment of the present invention; 
         FIG. 2A  is a side view of a commercially-available regulator; 
         FIG. 2B  is an end view of the regulator taken along line  2 - 2  in  FIG. 2A ; and 
         FIG. 3  is a view of the testing system taken along line  3 - 3  in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings and more particularly to  FIG. 1 , a system for testing a Self-Contained Breathing Apparatus (SCBA) regulator in accordance with an embodiment of the present invention is shown and is referenced generally by numeral  10 . While system  10  is configured and will be described for use with the commercially-available EZ FLOW models 1 and 2 manufactured by Scott Health and Safety, Monroe, N.C., the novel features of the present invention are readily adapted to any conventional regulator. 
     To provide a better understanding of the present invention, a brief description of the salient features of the above-cited regulator will be provided herein with simultaneous reference to  FIGS. 2A and 2B  where the regulator is referenced generally by numeral  100 . Regulator  100  includes a housing  102  from which a tube  104  extends and defines an opening  106  through which a user&#39;s breathing air passes. Tube  104  is terminated by opposing wings  108 A and  108 B. An annular sealing gasket  110  is seated in housing  102  and surrounds tube  104 . Gasket  110  is spaced apart from wings  108 A and  108 B and is partially overlapped thereby. 
     System  10  includes a hollow, cup-shaped housing  12  having rigid side walls  12 A and a top  12 B. Typically, housing  12  is a single integrated element and can be made of plastic, composites, metal, etc., without departing from the scope of the present invention. Walls  12 A and top  12 B define an interior volumetric region  14 , the perimeter of which is defined by walls  12 A as is more clearly visible in the end view of system  10  illustrated in  FIG. 3 . Walls  12 A terminate in top  12 B at one end of housing  12  and in a rim  12 C at the other (open) end of housing  12  where rim  12 C defines a hole  12 D. The shape of hole  12 D is commensurate with that of the outline of wings  108 A/ 108 B about tube  104  while the size of hole  12 D is just large enough to slip over wings  108 A/ 108 B. The portion of rim  12 C facing volumetric region  14  forms an annular lip  12 E. The thickness of rim  12 C at opening  12 D is slightly greater than the spacing between wings  108 A/ 108 B and gasket  110 . 
     To couple/seal housing  12  to regulator  100 , a user simply slips housing  12  over wings  108 A/ 108 B. Housing  12  is then pressed towards regulator  100  while rotating housing  12  one-quarter turn such that annular lip  12 E defined by rim  12 C engages wings  108 A/ 108 B while rim  12 C presses against gasket  110  so that rim  12 C can form a sealing fit therewith. Typically, rim  12 C defines a planar surface of constant or variable width W that simplifies the coupling of housing  12  to gasket  110 . 
     Mounted in top wall  12 B is a plunger-type syringe  20  having a hollow body  22 , a manually-operated plunger/piston mounted in body  22  and axially movable therein, and a dispensing tip  26  coupled to the end of body  22 . Tip  26  has an open end  26 A through which a fluid (not shown) can flow from or into body  22  when piston/plunger  24  is depressed into or retracted from, respectively, body  22 . Body  22  can also include volume gradations  28  marked thereon. A variety of such syringes are well known and commercially-available. 
     Syringe  20  is coupled to housing  12  in a manner that places open end  26 A in a sealed fluid communication with (volumetric region  14 . This can be achieved in a variety of ways without departing from the scope of the present invention. For example, in the illustrated embodiment, tip  26  is mounted/sealed in a hole  16  provided through top  12 B. However, the present invention is not so limited as additional structures could be provided to make the coupling of syringe  20  to housing  12  more robust. Such additional structures might include a body support structure integrated into top  12 B and surrounding hole  16  for coupling to a portion of body  22 . Furthermore, syringe  20  could be mounted in a side wall  12 A of housing  12  without departing from the scope of the present invention. 
     Although not required for the present invention, system  10  can also include a device  30  for measuring the pressure in volumetric region  14  during use of system  10 . Typically, device  30  is a pressure gauge capable of displaying a reading of positive or negative (vacuum) pressure. However, device could also be realized by a simple flexible diaphragm mounted in housing  12  and responsive to the pressure in volumetric region  14 . In this case, the concavity or convexity of the diaphragm would indicate whether a positive or negative pressure existed in volumetric region  14 . 
     In a testing operation, rim  12 C is coupled to regulator  100  and sealed against gasket  110  as described above. With piston/plunger  24  in its depressed state, testing begins by retracting plunger/piston  24  to develop a simulated breath inhalation/vacuum pressure in volumetric region  14 . The typical vacuum pressure to simulate a diver&#39;s inhalation is approximately −4 inches of water. If device  30  is present, retraction of plunger/piston  24  is continued until this vacuum pressure is achieved. Another option is for system  10  to be calibrated such that a particular gradation on body  22  is indicative of the desired vacuum pressure for a given volumetric region  14 . A simulated exhalation is achieved when plunger/piston  24  is depressed until a positive pressure of approximately +4 inches of water is achieved. Once again, device  30  can be used if it is present in system  10 . This cycle of simulated inhaling/exhaling is typically repeated a number of times to assure proper operation of the regulator. When testing is complete, housing  12  is simply separated from the face piece. 
     The advantages of the present invention are numerous. The testing system presents a solution to the testing of SCBA regulators that is simple, quick and sanitary. The reduction in time and energy makes such testing more affordable while reducing the tediousness of the task for testing personnel. 
     Although the invention has been described relative to a specific embodiment thereof, there are numerous variations and modifications that will be readily apparent to those skilled in the art in light of the above teachings. For example, the housing&#39;s rim and opening formed thereby can be sized/shaped for any regulator without departing from the scope of the present invention. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described.