You are an expert at summarizing long articles. Proceed to summarize the following text:

You are an expert at summarizing long articles. Proceed to summarize the following text: 
BACKGROUND OF THE INVENTION 
     Field of the Invention 
       [0001]    This disclosure relates to tubular diaphragms with means for regulation of flow of fluids, including liquids, gasses, and emulsions, through a passage, that incorporate the embodiments and concepts in this disclosure. 
       BRIEF SUMMARY OF THE INVENTION 
       [0002]    Embodiments comprise tubular diaphragms with a premolded shape giving them an enhanced lifetime in use. Embodiments include tubular diaphragms in which the premolded shape comprises a mechanical closure point. Embodiments include tubular diaphragms in which the premolded shape comprises a convolution area on at least one side of the tubular diaphragm. Embodiments also include tubular diaphragms in which the premolded shape comprises at least one side of the tubular diaphragm having a concave or convex shape. 
         [0003]    Embodiments include the method of manufacturing of a tubular diaphragm having an enhanced lifetime comprises the step of molding the tubular diaphragm to include a preformed concave or convex shape on at least one side of the tubular diaphragm. Embodiments include the method of molding the tubular diaphragm to include a preformed convolution on at least one side of the tubular diaphragm. Embodiments include the method of molding a preformed mechanical closure point which approximates a tubular diaphragm in the closed position. 
         [0004]    Embodiments include a tubular diaphragm which comprises a cylindrical tube manufactured of resilient elastomer with walls of approximately constant thickness throughout, an inlet flange and an outlet flange at the ends of the tube, and the tube having an upper and a lower side. There is a preformed mechanical closure point in which the inner surfaces of the upper and lower sides are separated by a gap of not greater than ⅓ of the diameter of the tube, the mechanical closure point located approximately at the middle of the length of the tubular diaphragm and dividing the diaphragm into an inlet and a outlet portion. There are preformed convolution areas on the upper and lower sides of at least one of the inlet and outlet portions, the convolution area located adjacent to a flange and extending in length from to about 25% of the length of a side and, in width to about 33% of the width of a side, the convolution areas having a concave or a convex form when viewed from the side of the tubular diaphragm. 
         [0005]    Embodiments are used in the same manner as conventional cylindrical diaphragms. In operation of both conventional and embodiments of this disclosure, the outlet portion is subjected to a vacuum. The inlet is subject to the pressure of fluid at or above atmospheric pressure. The diaphragm is enclosed in a chamber. The valve remains closed when there is atmospheric pressure inside the chamber. Reduction of pressure inside the chamber allows the diaphragm to open and assume an approximately cylindrical cross-section throughout the diaphragm, and allows the fluid at the inlet portion to flow through the diaphragm through the outlet section. 
         [0006]    Conventional cylindrical diaphragms are subject to fatigue failure, especially in the outlet portion of the diaphragm, because the valve is in the closed position for most of its life, and the outlet portion of the diaphragm is subject the greatest pressure differential with respect to the chamber. 
         [0007]    Embodiments of the present disclosure are highly resistant to fatigue failure and enjoy a substantially longer operational life than do conventional cylindrical diaphragms. Without being held to this explanation, the longer life of these embodiments is due to the mechanical closure point which is molded to approximate a closed preformed position. In embodiments, the movement of the top and bottom sides necessary to effect closure is minimized, as compared to conventional cylindrical diaphragms. In addition, the optional convolution areas on the top and bottom sides, and the optional shaped sides contribute to extended life in embodiments. Such tubular diaphragms are subject to lower stresses than conventional cylindrical diaphragms. 
         [0008]    The following embodiments and aspects thereof are described and illustrated in conjunction with embodiments which are meant to be exemplary and illustrative, not limiting in scope. In various embodiments, one or more of the above-described problems have been reduced or eliminated, while other embodiments are directed to other improvements. 
         [0009]    In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following descriptions. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
         [0010]      FIG. 1A  is a perspective view of the first embodiment tubular diaphragm in the rest position. 
           [0011]      FIG. 1B  is a side view of the first embodiment tubular diaphragm in the rest position. 
           [0012]      FIG. 1C  is a upper view of the first embodiment tubular diaphragm in the rest position. 
           [0013]      FIG. 1D  is an end view of the first embodiment tubular diaphragm in the rest position. 
           [0014]      FIG. 2  is a side view of the second embodiment tubular diaphragm in the rest position. 
           [0015]      FIG. 3  is a side view of the third embodiment tubular diaphragm in the rest position. 
           [0016]      FIG. 4  is a side view of the fourth embodiment tubular diaphragm in the rest position. 
           [0017]      FIG. 5  is a side view of the fifth embodiment tubular diaphragm in the rest position. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0018]    In this disclosure the term “tubular diaphragm” means a preshaped cylindrical elastomeric tube used in a valve. The valve is installed in a fluid transportation system. The term “fluid” means liquids, gasses, or emulsions. The term “waste” means an unwanted fluid, as, for example, from toilets, sinks, grease traps, etc. The term “rest position” means the tubular diaphragm not installed in a chamber and not subjected to a vacuum. Although the words “inlet” and “outlet” are used in the descriptions of the embodiments, these words are used simply to facilitate descriptions and not to limit the use of the embodiments. It is specifically contemplated that embodiments may be used with the “inlet” side on the lower pressure side and with the “outlet” side on the higher pressure side. 
       First Embodiment 
       [0019]      FIG. 1A  is a perspective view of the first embodiment tubular diaphragm  100  in the rest position. Visible in  FIG. 1A  is the inlet flange  103  located at a first end  101  of the tubular diaphragm, the upper side  115  of the tubular diaphragm, which is divided into the upper outlet side  113  and the upper inlet side  111  by the mechanical closure point  124  at approximately the middle of the upper side  115 . The mechanical closure point  124  divides the entire tubular diaphragm into the inlet portion  121  and the outlet portion  123 . 
         [0020]    The mechanical closure point  124  is preformed during the manufacturing process such that the upper interior surface  131  (in  FIG. 1D ) and lower interior surface  131  (in  FIG. 1D ) are not touching but are separated by a distance not larger then ⅓ of the diameter of the tubular diaphragm. 
         [0021]    Also visible in  FIG. 1A  is the inlet portion upper convolution area  122  and the outlet flange  107  located at the second end  102  of the tubular diaphragm. The convolution area extends approximately from the flange to about 25% of the length of the upper inlet side  111 . The convolution area extends in width to about 33% of the width of the upper inlet side  111 . A similar convolution area exists on the lower side of the tubular diaphragm and is shown in  FIG. 1B . 
         [0022]      FIG. 1B  is a side view of the first embodiment tubular diaphragm in the rest position. Visible in  FIG. 1B  is the inlet flange  103 , outlet flange  107 , the upper side  115 , and lower side  116 , both of which are divided by the mechanical closure point  124  at approximately the middle of the upper and lower sides into the upper outlet side  113  and upper inlet side  111 , and lower outlet side  125  and lower inlet side  127 , respectively. The mechanical closure point  124  also divides the entire tubular diaphragm into the inlet portion  121  and outlet portion  123 . Also visible in  FIG. 1B  is the inlet portion upper convolution area  122  and the inlet portion lower convolution area  128 . 
         [0023]    In the first embodiment as shown in  FIG. 1B  the inlet portion upper convolution area  122  extends from the inlet flange  103  at an approximate right angle and then curves downward to the upper inlet side  121  which extends in a straight line to the mechanical closure point  124 . The inlet portion lower convolution area  128  extends from the inlet flange  103  at an approximate right angle and then curves upward to the lower inlet side  127  which extends in a straight line to the mechanical closure point  124 . 
         [0024]    The outlet portion upper outlet side  113  extends from the outlet flange  107  in a concave curve which is continued by the upper outlet side  113  to the mechanical closure point  124 . The outlet portion lower outlet side  125  extends from the outlet flange  107  in a concave curve which is continued by the lower outlet side  125  to the mechanical closure point  124 . 
         [0025]      FIG. 1C  is a upper view of the first embodiment tubular diaphragm in the rest position. Visible in  FIG. 1C  is the inlet flange  103 , the upper side  115  of the tubular diaphragm, which is divided into the upper outlet side  113  and the upper inlet side  111  by the mechanical closure point at approximately the middle of the upper side  115 . Also visible in  FIG. 1C  is the inlet portion upper convolution area  122  and the outlet flange  107 . The convolution area extends approximately from the flange to about 25% of the length of the upper inlet side  111 . The convolution area extends in width to about 33% of the width of the upper inlet side. A similar convolution area exists on the lower side of the tubular diaphragm and is shown in  FIG. 1B . 
         [0026]      FIG. 1D  is an end view of the first embodiment tubular diaphragm in the rest position. Visible in  FIG. 1D  is the inlet flange  103 , the inner surface  131  of the upper side  115  and the inner surface  132  of the lower side  116 , and the mechanical closure point  124 , where the interior surfaces  131  and  132  of the upper side  115  and lower side  116 , respectively, touch when the valve is closed. In the rest position, as shown in  FIG. 1D , the inner surfaces of the walls are separated by a distance of less than about one third of the diameter of the tubular diaphragm. 
       Second Through Fifth Embodiments 
       [0027]    The second through fifth embodiments are like the first embodiment in the perspective view, upper view, and end view. Differences in the second through fifth embodiments from each other and from the first embodiment are shown in the side views,  FIGS. 2-5 . 
       Second Embodiment 
       [0028]      FIG. 2  is a side view of the second embodiment tubular diaphragm in the rest position. Visible in  FIG. 2  is the inlet flange  203 , outlet flange  207 , the upper side  215 , and the lower side  216 , both of which are divided by the mechanical closure point  224  at approximately the middle of the upper and lower sides into the upper outlet side  213  and upper inlet side  211 , and lower outlet side  225  and lower inlet side  227 , respectively. The mechanical closure point  224  also divides the entire tubular diaphragm into the inlet portion  221  and outlet portion  223 . Also visible in  FIG. 2  is the inlet portion upper convolution area  222  and the inlet portion lower convolution area  228 . 
         [0029]    In the second embodiment as shown in  FIG. 2  the inlet portion upper convolution area  222  extends from the inlet flange  203  as a convex bump which then curves downward to the upper inlet side  221  which extends in a straight line to the mechanical closure point  224 . The inlet portion lower convolution area  228  extends from the inlet flange  203  as a convex bump and then curves upward to the lower inlet side  227  which extends in a straight line to the mechanical closure point  224 . 
         [0030]    The outlet portion upper convolution area  220  extends from the outlet flange  207  as a convex bump which then curves downward to the upper outlet side  213  which then curves downward to the mechanical closure point  224 . The outlet portion lower convolution area  226  extends from the outlet flange  207  as a convex bump and then curves upward to the lower inlet side  225  which extends in a straight line to the mechanical closure point  224 . 
       Third Embodiment 
       [0031]      FIG. 3  is a side view of the third embodiment tubular diaphragm in the rest position. Visible in  FIG. 3  is the inlet flange  303 , outlet flange  307 , the upper side  315 , and lower side  316 , both of which are divided by the mechanical closure point  324  at approximately the middle of the upper and lower sides into the upper outlet side  313  and upper inlet side  311 , and lower outlet side  325  and lower inlet side  327 , respectively. The mechanical closure point  324  also divides the entire tubular diaphragm into the inlet portion  321  and outlet portion  323 . Also visible in  FIG. 3  is the inlet portion upper convolution area  322  and the inlet portion lower convolution area  328 . 
         [0032]    In the third embodiment as shown in  FIG. 3  the inlet portion upper convolution area  322  extends from the inlet flange  303  as a concavity and then curves downward to the upper inlet side  321  which extends in a straight line to the mechanical closure point  324 . The inlet portion lower convolution area  328  extends from the inlet flange  303  as a concavity and then curves upward to the lower inlet side  327  which extends in a straight line to the mechanical closure point  324 . 
         [0033]    The outlet portion upper convolution area  320  extends from the outlet flange  307  as a concavity and then curves downward to the upper inlet side  313  which extends in a straight line to the mechanical closure point  324 . The outlet portion lower convolution area  326  extends from the outlet flange  307  as a concavity and then curves upward t the lower outlet side  325  which extends in a straight line to the mechanical closure point  324 . 
       Fourth Embodiment 
       [0034]      FIG. 4  is a side view of the fourth embodiment tubular diaphragm in the rest position. Visible in  FIG. 4  is the inlet flange  403 , outlet flange  407 , the upper side  415 , and lower side  416 , both of which are divided by the mechanical closure point  424  at approximately the middle of the upper and lower sides into the upper outlet side  413  and upper inlet side  411 , and lower outlet side  425  and lower inlet side  427 , respectively. The mechanical closure point  424  also divides the entire tubular diaphragm into the inlet portion  421  and outlet portion  423 . Also visible in  FIG. 4  is the inlet portion upper convolution area  422  and the inlet portion lower convolution area  428 . In the fourth embodiment as shown in  FIG. 4  the inlet portion upper convolution area  422  extends from the inlet flange  403  as a concavity and then curves downward to the upper inlet side  421  which extends in a straight line to the mechanical closure point  424 . The inlet portion lower convolution area  428  extends from the inlet flange  403  as a concavity and then curves upward to the lower inlet side  427  which extends in a straight line to the mechanical closure point  424 . The outlet portion upper convolution area  420  extends from the outlet flange  407  as a convex bump which then curves downward to the upper outlet side  413  which extends in a straight line to the mechanical closure point  424 . The outlet portion lower convolution area  426  extends from the outlet flange  407  as a convex bump and then curves upward to the lower inlet side  425  which extends in a straight line to the mechanical closure point  424 . 
       Fifth Embodiment 
       [0035]      FIG. 5  is a side view of the fifth embodiment tubular diaphragm in the rest position. Visible in  FIG. 5  is the inlet flange  503 , outlet flange  507 , the upper side  515 , and lower side  516 , both of which are divided by the mechanical closure point  524  at approximately the middle of the upper and lower sides into the upper outlet side  513  and upper inlet side  511 , and lower outlet side  525  and lower inlet side  527 , respectively. The mechanical closure point  524  also divides the entire tubular diaphragm into the inlet portion  521  and outlet portion  523 . Also visible in  FIG. 5  is the inlet portion upper convolution area  522  and the inlet portion lower convolution area  528 . 
         [0036]    In the fifth embodiment as shown in  FIG. 5  the inlet portion upper convolution area  522  extends from the inlet flange  503  at an approximate right angle and then curves downward to the upper inlet side  521  which extends in a straight line to the mechanical closure point  524 . The inlet portion lower convolution area  528  extends from the inlet flange  503  at an approximate right angle and then curves upward to the lower inlet side  527  which extends in a straight line to the mechanical closure point  524 . 
         [0037]    The outlet portion upper convolution area  520  extends from the outlet flange  507  on a downward straight line which is continued by the upper outlet side  513  to the mechanical closure point  524 . The outlet portion lower convolution area  526  extends from the outlet flange  507  on an upward straight line which is continued by the lower outlet side  525  to the mechanical closure point  524 . 
       General 
       [0038]    In embodiments, the diameter of the tubular diaphragm ranges from ½ inch to 12 inches. In embodiments, the length of the tubular diaphragm will range from 3 inches to 36 inches. 
         [0039]    Embodiment tubular diaphragms are manufactured of any suitable resilient polymeric material. Suitable materials include natural rubber, polypropylene, polyethylene, polyvinylidene fluoride, nitrile rubber, ethylene propylene diene monomer rubber, butyl rubber, vinylidene fluoride monomer fluoroelastomers, silicone rubber, fluorinated ethylene propylene, perfluoroalkoxy, and polytetrafluoroethylene. Nitrile rubber, ethylene propylene diene monomer rubber, and butyl rubber are especially suitable. 
         [0040]    Embodiments may be manufactured by any suitable method. Methods of manufacture include injection molding, and extrusion. Compression molding, transfer molding or injection molding are especially suitable methods. 
         [0041]    In embodiments, optional tethers are attached on either side of the mechanical closure point. Such tethers interact with and slide into guides which assist the complete opening of the tubular diaphragm. 
         [0042]    Although examples in this disclosure include the use of embodiments in the operation of vacuum toilets, it is specifically contemplated that the embodiment tubular diaphragms will find utility in other applications in the movement of fluids when there is a pressure differential between the inlet and outlet of the tubular diaphragms. 
         [0043]    Embodiment tubular diaphragms exhibit in particular the advantage of enhanced resistance to failure when compared to conventional cylindrical diaphragms. This resistance is expressed especially in the outlet portion, which is subject to the maximum pressure differential when the tubular diaphragm is closed, which is the normal condition. 
         [0044]    Without wishing to be held to this explanation, the enhanced resistance of embodiments stems from the fact that the premolded mechanical closure point minimizes the flexation of the tubular diaphragm required when it is in the closed position. In particular, since the tubular diaphragm is in the closed position for the vast majority of time it is in use, the premolded mechanical closure point which approximates the closed position minimizes the stress involved in putting the tubular diaphragm in the closed position. 
         [0045]    In addition, the convolution areas or the interaction of convolution areas and sides adds to the lifetime of the tubular diaphragms. The convolution areas relieve stresses normally on the tubular diaphragms. The effect of the convolution areas and the shape of the sides enhance the advantages provided by the preformed mechanical closure point. 
         [0046]    Advantages from the extended life of embodiments include reduction of the cost of replacement valves, reduction of the labor required to replace worn-out valves, and avoidance of capital costs associated with redundant facilities needed when valves fail. 
         [0047]    In embodiments, a tubular diaphragm is normally in the closed position and is opened only when desired. A variety of opening mechanisms can be used. A vacuum mechanism is commonly used, in which the tubular diaphragm is enclosed in a chamber while the atmospheric air pressure and spring pressure maintains the tubular diaphragm in the closed position. The tubular diaphragm is opened when air is evacuated from the chamber. The opening of the tubular diaphragm may be assisted by mechanical means attached to tethers located at the mechanical closure point. Other means of operating the tubular diaphragms are contemplated. 
         [0048]    While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations as are within their true spirit and scope. The applicant or applicants have attempted to disclose all the embodiments of the invention that could be reasonably foreseen. There may be unforeseeable insubstantial modifications that remain as equivalents.

Summary:
Embodiments include tubular diaphragm valves with a preformed mechanical closure point and optionally concave or convex convolution areas located near the flanges. These mechanical closure points and convolution areas give the embodiments an extended operational life, as compared to that of conventional cylindrical diaphragms.