Abstract:
A breathing bag including a distensible bag portion and an integrally formed neck portion thicker than the distensible bag portion and sufficiently thick to be connected directly to a male fitting; the distensible bag portion may be fluted.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]     This application is a continuation application of pending application Ser. No. 10/843,769, filed May 12, 2004, which is a divisional application of application Ser. No. 10/176,906, filed Jun. 21, 2002, both entitled PROCESS OF MANUFACTURING A BREATHING BAG AND BREATHING BAG MANUFACTURED BY SUCH PROCESS, Jack H. Britten, et al., inventors, and assigned to the same assignee as this continuation application. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     This invention relates to a breathing bag including connector and distensible portions.  
         [0003]     Breathing bags are well known to the medical arts for delivering, or assisting in delivering, gas to a patient such as anesthesia gas or a breathing gas such as oxygen or oxygen-enriched air. Typical prior art breathing bags are illustrated diagrammatically in  FIGS. 1A and 1B ,  FIGS. 2A and 2B ,  FIGS. 3A, 3B ,  3 C and  3 D and  FIGS. 4A, 4B  and  4 C.  
         [0004]     These prior art breathing bags typically include connector and distensible portions which are fluted, and hence, such prior art breathing bags are typically referred to as fluted breathing bags or breathing bags having a fluted distensible portion.  
         [0005]     In use, for example, in an anesthesia circuit for supplying anesthesia gas to a patient&#39;s lungs, the prior art breathing bag of  FIGS. 3A , B and C includes a connector portion  3   d  and a fluted distensible portion  3   e  which is filled with pressurized anesthesia gas, pressurized to the normal operating pressure, and the fluted distensible portion  3   e , shown in its manufactured shape in cross-section in  FIG. 3C , is distended, expanded or stretched, outwardly into the circular cross-section shape S 1  shown in  FIG. 3D  which is the pressurized anesthesia gas filled normal operating state of the distensible breathing bag portion. Thereafter, the anesthesiologist alternately squeezes and relaxes the distensible portion  3   e  to supply the appropriate amount of anesthesia gas to the lungs of the patient. The thinness of the distensible portion  3   e  permits it to initially distend or expand outwardly from the manufactured state or shape shown in  FIG. 3C  into the normal operating state S 1  shown in  FIG. 3D  and to re-distend, or re-expand, into the normal operating state S 1  after the anesthesiologist has relaxed the squeezing in supplying anesthesia gas to the patient. In the event an unintended increase in anesthesia gas pressure occurs in the anesthesia circuit, such as an unintended anesthesia gas pressure surge, the distensible portion  3   e  is also sufficiently thin to permit the distensible portion to further distend, expand or stretch, and outwardly into the further distended state S 2  shown in  FIG. 3D . (This further distension of the distensible portion  3   e  into state or shape S 2  permits it to increase its volume and receive or accommodate the unintended anesthesia gas pressure increase and prevent such pressure increase from reaching and possibly damaging the patient&#39;s lungs. Accordingly, it will be understood that the term distensible portion as used hereinafter, and in the appended claims, is defined to mean a breathing bag distensible portion that is sufficiently thin to distend or expand outwardly from its manufactured state into a pressurized gas filled normal operating state and to contract and re-distend into its normal operating state upon being alternately squeezed and relaxed, and to further distend or expand outwardly into a further distended state to increase its volume and receive and accommodate an increase in gas pressure.  
         [0006]     Typically, in the prior art, such breathing bags are made by the dipping process much like the process used for producing a candle. A form is made in the shape of the breathing bag desired and the form is dipped repeatedly into a fluid suitable for producing a breathing bag such as, for example, a latex or non-latex fluid. Such process is typically slow, unwantedly expensive and lends itself to imperfections.  
         [0007]     Further, the typical prior art breathing bag made by the aforenoted dipping process and has a relatively thin wall thickness such that the connector portion is insufficiently stiff or rigid to connect, for example, to a standard 22 mm tapered male fitting or a non-tapered tubular or hollow cylindrical fitting. More particularly and referring to  FIGS. 5 and 5 A, these FIGS. show a typical prior art breathing bag made by the above-noted dipping process and each breathing bag includes a distensible portion  2  and a generally cylindrical neck or connector portion  4 . Having been made by the above-noted dipping process, the distensible portion  2  and the neck or connector portion  4  are typically 0.010-0.015 inch thick. Such thickness means that the neck portions  4  are insufficiently stiff or rigid to be connected directly to one of the above-noted male fittings. Hence, as is further known to the art, these prior art breathing bags made by the dipping process require the addition of a separate cylindrical bushing such as the bushings  5  and  6  shown respectively in  FIGS. 5 and 5 A to be inserted into the neck or connector portion to provide the required stiffness or rigidity to permit these breathing bags, namely the connector portion, to be connected to the above-noted male fittings. Typically, such bushings  5  and  6  are made from polyvinyl chloride and have a wall thickness of about 0.125 inch. Although such bushings  5  and  6  are sufficiently rigid or stiff to permit the connector portions of the breathing bags to be connected to one of the above-noted fittings, such bushings are still sufficiently soft to permit the bushings to slidably or wedgedly engage the above-noted male fittings. As will be noted from  FIG. 5 , the bushing  5  has an inwardly tapered internal wall for being fitted to a tapered male fitting in a sliding or wedged air-tight engagement, and the bushing  6  in  FIG. 5A  has a straight or cylindrical internal wall for air-tight sliding or wedged engagement with a tubular or cylindrical fitting. Further, as will be understood from  FIG. 5A , to retain the bushings  5  and  6  in the neck or connector portion  4  of these breathing bags, an additional element is included such as the surrounding retaining ring or band  7  shown in  FIG. 5A  which surrounds the bag neck portion  4  sufficiently tightly so as to retain the bushing  6  in the neck portion of the breathing bag. At least certain of the bushings are provided with anti-occlusion members for preventing occlusion of the internal airway between the distensible and connector portions in the event the distensible portion is bent acutely with respect to the connector portion. As is further known to the art, the requirement of these additional bushings, the retaining bands, and the manufacturing steps required to insert and retain the bushings in the breathing bags further add unwanted cost and expense to the manufacture of the typical prior art breathing bag.  
         [0008]     Accordingly, there is a need in the breathing bag art for a new and improved breathing bag which has a neck or connector portion formed integrally with the distensible portion and which neck or connector portion is sufficiently thick, stiff or rigid, to permit it to connect directly to a male fitting of the types noted above, the distensible portion may be fluted.  
       SUMMARY OF THE INVENTION  
       [0009]     A breathing bag including integrally formed connector portion and distensible portion the connector portion being sufficiently thick to permit the connector portion to be connected directly to a male fitting; the distensible portion may be fluted. 
     
    
     DESCRIPTION OF THE DRAWINGS  
       [0010]      FIGS. 1A  and B illustrate, respectively, a side elevational view of a double fluted standard prior art breathing bag with a nipple,  FIG. 1B  shows the flutes and is rotated approximately 45° with respect to  FIG. 1A ;  
         [0011]      FIGS. 2A and 2B  show a bag similar to that shown in  FIGS. 1A and 1B  except the prior art bag in  FIGS. 2A and 2B  does not include the nipple;  
         [0012]      FIG. 3A  is a side elevational view of a double fluted prior art paddle bag with a nipple and  FIG. 3B  shows the bag of  FIG. 3A  rotated approximately 45° and illustrates the double flute,  FIG. 3C  is a cross-sectional view taken generally along the line  3 - 3  in  FIG. 3B  in the direction of the arrows and illustrates more clearly the double fluting;  
         [0013]      FIG. 3D  is a double cross-sectional view taken generally along the line  3 - 3  in  FIG. 3B  but showing the distensible portion of the breathing bag distended into the normal operating state upon receiving pressurized gas and further distended into a further distended state to accommodate an increase in gas pressure.  
         [0014]      FIG. 4A  is a side elevational view of a standard prior art breathing bag with triple flutes which flutes are shown in  FIG. 4B  which FIG. is rotated approximately 45° with respect to  FIG. 4A , this bag also is provided with a nipple,  FIG. 4C  is a diagrammatical cross-sectional view taken generally along the line  4 - 4  in  FIG. 4B  in the direction of the arrows and shows more clearly the triple fluting;  
         [0015]      FIGS. 5 and 5 A, illustrate, in perspective, still further breathing bags known to the prior art;  
         [0016]      FIG. 6  is a side elevational view of a breathing bag embodying the present invention and made by the process of the present invention;  
         [0017]      FIG. 6A  is an enlarged view in cross-section of the encircled portion of  FIG. 6 ;  
         [0018]      FIGS. 7-9  illustrate, diagrammatically, the process of the present invention for manufacturing a breathing bag and also illustrate, diagrammatically, apparatus suitable for practicing such process;  
         [0019]      FIG. 8A  is a diagrammatical illustration of a portion of a combination blowing and forming member which may be included in the apparatus for practicing the process of the present invention;  
         [0020]      FIG. 9A  is a cross-section taken generally along the line  9 A- 9 A in  FIG. 9  and in the direction of the arrows; and  
         [0021]      FIGS. 10-12  illustrate, diagrammatically, a second embodiment of the process of the present invention for manufacturing a breathing bag and further illustrate, diagrammatically, apparatus suitable for practicing such process. 
     
    
       [0022]     It will be generally understood that the opposite sides of the bags shown in  FIGS. 1B, 2B ,  3 B and  4 B are also provided with flutes in the same manner as the sides of these bags shown in these FIGS.  
       DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0023]     A breathing bag embodying the present invention is illustrated diagrammatically in  FIGS. 6 and 6 A and indicated by alphabetical designation B. Breathing bag B includes a generally cylindrical connector portion C and a distensible portion D. The connector portion C is typically sized to connect directly to an ISO 22 mm male fitting and the distensible bag D expands and contracts in the process of delivering, or assisting in delivering, gas to the patient as noted above. As will be better understood from  FIG. 6A , the connector portion C has a greater thickness than the thickness of the distensible portion D; the greater thickness of the connector portion C provides it with the strength or rigidity to serve its above-noted connector function. For illustration the thickness of the connector portion C has been exaggerated with respect to the thickness of the distensible portion D in  FIG. 6A . In one embodiment, the distensible portion D had a thickness or wall thickness T1 of about 0.015-0.020 inch and the neck portion C had a thickness or wall thickness T2 of about 0.125 inch. In accordance with the teaching of the present invention, the greater thickness T2 of the neck or connector portion C provides sufficient rigidity or stiffness to permit such neck portion C to connect the breathing bag B,  FIGS. 6 and 6 A, directly to the above-noted male fittings, and yet be sufficiently flexible or soft that it can engage such fittings in a sliding or wedged air-tight engagement.  
         [0024]     As shown in  FIG. 6A , an internal airway is provided between the distensible and connector bag portions. In the breathing bag of the present invention internal anti-occlusion ridges E ( FIG. 6A ) may be molded into the integral connection between the distensible and connector portions to maintain a positive airway between these portions. The distensible portion D,  FIG. 6 , of the breathing bag B may be a fluted distensible portion as indicted by the area F.  
         [0025]     The process for manufacturing a breathing bag according to the present invention is illustrated diagrammatically in  FIGS. 7-9 . Such process will be described by way of example with respect to a process for manufacturing the breathing bag B illustrated in  FIGS. 6 , and  6 A. Also illustrated diagrammatically in  FIGS. 7-9  are apparatus indicated by general numerical designation  10  suitable for practicing such process. Apparatus  10  may include an extruder  12  for extruding a hollow tubular parison of thermoplastic material suitable for making the breathing bag B. As known to the art, a parison is a hollow tubular length of relatively molten, or semi-molten, thermoplastic material. The apparatus  10  further includes a hot cutting knife  13  for cutting the parison, a pair of holding jaws  14  and  16 , and a pair of opposed main molds  18  and  20 . The holding jaws and the main molds are mounted for sliding reciprocal movement toward and away from each other and function in the manner known to the art.  
         [0026]     The main molds  18  and  20  are provided with connector forming portions  26  and  27  for forming the exterior of the connector portion C of the breathing bag B ( FIGS. 5, 6  and  6 A) and are further provided with opposed centrally formed mold cavities  29  and  30  for forming the distensible portion D of the breathing bag B. The forming portions  26  and  27  of the main molds  18  and  20  are complementary in shape to the exterior of the connector portion C of the breathing bag B of  FIGS. 5, 6  and  6 A and the mold cavities  29  and  30  are complementary in shape to the distensible portion D of the breathing bag B.  
         [0027]     Referring to  FIG. 8A , the apparatus  10  may further include a combination blowing and forming member indicated by general numerical designation  36 . The member  36  is provided with a centrally formed passageway  37  through which pressurized air is blown into the interior of the parison to expand and force a portion of the parison wall into the mold cavities  29  and  30  ( FIG. 9 ) and is further provided with an external surface  38  for forming the internal surface, or hollow interior portion of the connector portion C of the breathing bag B ( FIG. 6A ). It will be understood that such external surface  38  is shaped complementarily to the external shape of the male fitting to which the connector portion C,  FIG. 6A , of the breathing bag B will engage in a sliding or wedged air-tight fit. Accordingly, such external surface  38  of the combination blowing and forming member  36  may be provided with a shape so as to provide the connector portion C,  FIG. 6A , or the hollow interior portion thereof, with a tapered shape or a non-tapered straight or cylindrical shape for receiving either a tapered male fitting or a non-tapered male fitting in a sliding or wedged air-tight engagement.  
         [0028]     The process for manufacturing a breathing bag in accordance with the present invention, and with regard to the breathing bag B of  FIGS. 5 and 6  by way of example, will now be described in reference to  FIGS. 7-9 . The parison P,  FIG. 7 , is extruded downwardly by the extruder  12  between the pairs of open holding jaws  14  and  16  and main molds  18  and  20  as shown in  FIG. 7 . As shown in  FIG. 8 , the holding jaws  14  and  16  are advanced into engagement with the upper portion of the parison P, vacuum is drawn in the vacuum lines  21  and  22 , and the cavities  23  and  24  to secure the parison P between the open main molds  18  and  20 . The hot cutting knife  13  cuts off the upper portion of the parison P and the extruder  12  ( FIG. 7 ) is suitably indexed away. The combination blowing and forming member  36  is then suitably indexed into position over the open upper portion of the parison P,  FIG. 8 , and is inserted into the upper portion of the parison P as indicated by the arrow  41  in  FIG. 8A .  
         [0029]     As further illustrated in  FIG. 9 , the main molds  18  and  20  are advanced toward an engagement with each other to cause the connector forming portions  26  and  27  and the outer surface  38  of the combination blowing and forming member  36  to compression form or mold therebetween the upper portion of the parison P into the generally cylindrical connector portion C of the breathing bag B ( FIG. 6 ). Pressurized air is blown into the interior of the parison P through the passageway  37  formed in the combination blowing and forming member  36  to expand and force the lower portion of the parison P into engagement with the surfaces defining the mold cavities  29  and  30  to thereby blow mold the distensible portion D of the breathing bag B ( FIG. 6 ).  
         [0030]     Referring to  FIG. 9A , it will be understood that the mold surfaces  29  and  30  of the molds  18  and  20  may be suitably shaped to provide the distensible portion D of the breathing bag B of the present invention with flutes, such as the double flutes of the prior art breathing bag illustrated diagrammatically in  FIG. 3C  and described above. Hence, it will be understood that the breathing bag B of the present invention upon having a fluted distensible portion D may be referred to as a fluted breathing bag or a breathing bag having a fluted distensible portion.  
         [0031]     The combination blowing and forming member  36  is withdrawn and the main molds  18  and  20  are then retracted or opened and the now formed breathing bag B, of  FIG. 6 , has been manufactured in accordance with the manufacturing process of the present invention.  
         [0032]     It will be understood in accordance with the further teachings of the present invention that if desired or required, the blow-molding step may be accompanied by a vacuum assisted molding step to further enhance the molding of the distensible portion D of the breathing bag B of  FIG. 6 . In such event, this additional method step will be practiced by providing the main molds  18  and  20 ,  FIGS. 8-9 , with vacuum lines or channels  32  for applying vacuum to the lower portion of the parison P ( FIG. 9 ) to assist in expanding and forcing such portion of the parison P into the mold cavities  29  and  30 .  
         [0033]     Referring again to  FIG. 6A , and as noted above, the generally cylindrical connector portion C of the breathing bag B is thicker than the thickness of the distensible portion D. It has been found that it is further desirable to provide additional parison material in the breathing bag manufacturing process to enhance the forming of the connector portion C of the breathing bag B so as to have a greater thickness than the distensible portion D of the breathing bag. Accordingly, and referring now to  FIGS. 10-12 , an alternate process for manufacturing a breathing bag according with the present invention is illustrated diagrammatically and apparatus suitable for practicing this alternate process is also illustrated diagrammatically in these figures and indicated by general numerical designation  10 A. It will be understood that the components comprising the apparatus  10 A in  FIGS. 10-12  which are the same as the components comprising the apparatus  10  in  FIGS. 7-9  are given the same numerical designations in  FIGS. 10-12  and will be understood to perform the same functions.  
         [0034]     It has been discovered that upon the parison P,  FIG. 11 , being extruded vertically downwardly, that at least the lower portion of the parison P increases in thickness with respect to the upper portion of the parison under the influence of gravity. It has been further discovered that this thickening of the lower portion of the parison P can be utilized advantageously in forming the generally cylindrical connector portion C of the breathing bag B of  FIGS. 6 and 6 A. The thickening of the lower portion of the parison P under the influence of gravity is illustrated diagrammatically in  FIG. 11  by the cross-sectioned lower portion of such parison.  
         [0035]     It will be generally understood, that the primary difference between the alternate embodiment process of  FIGS. 10-12  and the foregoing described process of  FIGS. 7-9  is that the breathing bag in  FIGS. 10-12  is formed upside down with respect to the orientation of the breathing bag formed by the process illustrated diagrammatically in  FIGS. 7-9 . Accordingly, and referring to  FIG. 11 , the parison P of hollow cylindrical suitable thermoplastic material is extruded vertically downwardly between the open main molds  18  and  20  and the lower portion of such parison is extruded downwardly by the extruder  12  over the combination blowing and forming member  36  and the lower portion of the parison P is allowed to increase in thickness under the influence of gravity. The main molds  18  and  20 ,  FIG. 12 , are advanced into engagement with each other, the cutting knife  13  cuts the parison P, the extruder  12  is suitably indexed out of the way, and pressurized air is blown into the interior of the upper portion of the parison P through the combination blowing and forming member  36  and, if desired or required, vacuum is drawn against the exterior of the upper portion of the parison P through the vacuum lines  32  to force the upper portion of the parison P into the mold cavities  29  and  30  and to expand such upper portion of the parison P to form the distensible portion D of the breathing bag B of  FIG. 6  by pressure molding or by pressure and vacuum molding. The connector forming portions  26  and  27  of the main molds  18  and  20  and the outer forming surface  38  of the combination blowing and forming member  36  engage the lower portion of increased thickness of the parison P and compression mold or form therebetween the connector portion C of the breathing bag B as illustrated diagrammatically in  FIG. 12 .  
         [0036]     Thereafter, the main molds are retracted into the open position shown in  FIGS. 10 and 11  and the combination blowing and forming member  36  is withdrawn and suitably indexed away and the breathing bag B of  FIGS. 5 and 6  is removed.  
         [0037]     It has been found, by way of example and not by way of limitation, that a thermoplastic material from QST Inc., Ateknor Apex Co., 300 Industrial Park Road, St. Albans, Vt., sold under the trademark MONOPRENE, is suitable for use in the processes of the present invention for manufacturing a breathing bag.  
         [0038]     Referring again to the parison P,  FIGS. 7, 8  and  11 , it will be understood that the tubular parison P may be circular in cross-section, rectangular in cross-section, or of other cross-sectional shapes to enhance the manufacture of the breathing bag in accordance with the processes of the present invention.  
         [0039]     It will be understood that many variations and modifications may be made in the present invention without departing from the spirit and scope thereof.