Abstract:
A tubing valve is provided, including a valve body; a valve stem configured to be inserted into the valve body; and a valve tip configured to be inserted and fixed into the valve stem on its top part after it is positioned inside the valve body and to provide a holding position to a tube on its bottom side, wherein the tubing valve is opened upon pushing the valve tip and closed upon pulling said tube off the valve tip.

Description:
BACKGROUND 
     The present invention relates generally to a novel tubing valve that may be used in low and medium pressure applications in general, and in particular to a novel medical valve that may be used for example in systems for removal of urine from catheterized patients to thereby allow avoiding any contact with the patient&#39;s urine. 
     There are many situations in which a medical team needs to engage with liquids secretion systems as well as with diagnostic and therapeutic systems that require replacement of disposable collecting bags that contain liquids. Such engagement usually results in leakage of liquids that contaminates both the near surroundings, and the hands of the medical team with liquids such as urine, blood, or other toxic and cytotoxic matter. 
     SUMMARY 
     The present invention, in at least some embodiments is directed to a novel tubing valve which is particularly applicable to medical uses. For medical uses, the medical tubing valve may optionally be used for urine collection systems, for example to permit a collecting bag that is in use to be removed and to be replaced by a fresh bag, while preventing any contact between the medical team performing the replacement and the liquids in the collecting bag, and therefore keeping the near surrounding and medical staff clean. 
     According to at least some embodiments of the present invention, there are provided hygienic systems and methods for collecting urine from a patient, wherein the systems comprise a novel medical tubing valve that functionally prevents direct contact between the medical team and the urine. 
     The valve may also optionally be used for non-medical applications, for example in situations where it is desirable to prevent contact with undesirable substances upon changing receptacles for such substances that are connected to tubing. These applications might include drawing off samples of corrosive fluid from a flow, checking fluid concentrations, checking fluid residue, or draining fluid residues in general. 
     According to at least some embodiments, there is provided a tubing valve, comprising: a valve body; a valve stem adapted to be inserted into the valve body where the valve stem has an inlet port; and a valve tip adapted to be inserted and fixed into the valve stem after a first end of the valve tip is positioned inside the valve body, wherein a second end of the valve tip is adapted to hold a tube, wherein the tubing valve is adapted to open upon attaching the tube to the valve tip, causing the valve stem to move away from the valve body and to permit fluid access to the inlet port, and is adapted to close upon removing the tube from the valve tip, causing the valve stem to move toward the valve body and to block fluid access to the inlet port. 
     Optionally the valve body further comprises a central bore, wherein the valve stem comprises a first portion having a greater area and a second portion having a smaller area, wherein a portion of the central bore is narrower than a second portion of the central bore, the narrower portion receiving the second portion of the valve stem and the second portion of the central bore receiving the first portion of the valve stem having the greater area. 
     Also optionally the first end of the valve tip contacts the second portion of the valve stem and causes the valve stem having the inlet port to move away from the valve body to open the valve. 
     Also optionally the second end of the valve tip is adapted to be inserted into the tube and is adapted to cause the first end of the valve tip to contact the second portion of the valve stem. 
     Also optionally the narrower portion of the central bore is adapted to be inserted into the tube with the second end of the valve tip, thereby preventing the valve from closing when the tube is attached to the valve. 
     Also optionally the second end of the valve tip is adapted to move away from the valve body upon removal of the tube and hence to cause the first end of the valve tip to cease to contact the second portion of the valve stem having the inlet port, thereby closing the valve. 
     Also optionally the valve stem and the central bore of the valve body each comprise complementary conical structures, such that when the tubing valve is closed, the conical structure of the valve stem having the inlet port is larger than the conical structure of the central bore, thereby blocking the inlet port. 
     According to at least some embodiments of the present invention, there is provided a tubing valve, comprising: a valve body having a flow control mechanism consisting essentially of a valve stem having an inlet port adapted to be inserted into the valve body and a valve tip adapted to be inserted and fixed into the valve stem after a first end of the valve tip is positioned inside the valve body, wherein a second end of the valve tip is adapted to hold a tube, wherein the tubing valve is opened upon attaching the tube to the valve tip, causing the valve stem to move away from the valve body and to permit fluid access to the inlet port, and closed upon removing the tube from the valve tip, causing the valve stem to move toward the valve body and to block fluid access to the inlet port. 
     Optionally the valve is adapted to be used in low and medium pressure applications. 
     Optionally the valve further comprises a medical tube attached to the valve. 
     Also optionally the valve is positioned in a urinary catheter system, and wherein the medical tube is a urine collecting bag tube. 
     According to at least some embodiments of the present invention there is provided an urinary catheter system comprising: a catheter for insertion to the patient, a urine collection bag, a urine collection bag tube, a tubing valve, and a tube having an inner diameter from four millimeters to six millimeters, the tube having an inner surface which is hydrophobic at least along a first segment thereof and being adapted to provide a continuously negative fluid pressure therein, the tube being connected to the catheter at one end of the tube, and the tube being connected to one end of the tubing valve at an opposite end of the tube, and the valve being connected to the urine collection bag tube at an opposite end of the valve such that the tube conveys a column of fluid held by a meniscus of the column of fluid from the catheter to the collection bag without interruption; wherein the valve is adapted to be open upon connecting the urine collection bag tube and the valve is adapted to be closed upon disconnecting the urine collection bag tube. 
     Optionally the system further comprises a drop counter, wherein at the opposite end of the tube, the tube is connected to the drop counter and the tubing valve is connected to the drop counter. 
     Also optionally the tubing valve comprises: a valve body adapted for connecting to the drop counter; a valve stem adapted to be inserted into the valve body where the valve stem has an inlet port; and a valve tip adapted to be inserted and fixed into the valve stem after a first end of the valve tip is positioned inside the valve body, wherein a second end of the valve tip is adapted to hold the urine collection bag tube, wherein the tubing valve is adapted to open upon attaching the urine collection bag tube to the valve tip, causing the valve stem and the inlet port to move away from the valve body and to permit fluid access to the inlet port, and is adapted to close upon removing the tube from the valve tip, causing the valve stem and the inlet port to move toward the valve body and to block fluid access to the inlet port. 
     Also optionally the valve body further comprises a central bore, wherein the valve stem comprises a first portion having a greater area and a second portion having a smaller area, wherein a portion of the central bore is narrower than a second portion of the central bore, the narrower portion receiving the second portion of the valve stem and the second portion of the central bore receiving the first portion of the valve stem having the greater area. 
     Also optionally the first end of the valve tip is adapted to contact the second portion of the valve stem and is adapted to cause the valve stem having the inlet port to move away from the valve body to open the valve. 
     Also optionally the second end of the valve tip is adapted to be inserted into the urine collection bag tube and is adapted to cause the first end of the valve tip to contact the second portion of the valve stem. 
     Also optionally the narrower portion of the central bore is adapted to be inserted into the urine collection bag tube with the second end of the valve tip, thereby preventing the valve from closing when the urine collection bag tube is attached to the valve. 
     Also optionally the second end of the valve tip is adapted to move away from the valve body upon removal of the urine collection bag tube and hence to cause the first end of the valve tip to cease to contact the second portion of the valve stem having the inlet port, thereby closing the valve. 
     Also optionally the valve stem and the central bore of the valve body each comprise complementary conical structures, such that when the tubing valve is closed, the conical structure of the valve stem having the inlet port is larger than the conical structure of the central bore, thereby blocking the inlet port. 
     According to at least some embodiments of the present invention there is provided a method for enhanced continuous flow of urine in a catheterized patient comprising: providing an arrangement comprising a hydrophobic tube having an inner diameter of from four to six millimeters, the tube having an inner surface which is hydrophobic at least along a first segment thereof and being arranged to provide a continuously negative fluid pressure therein; attaching the hydrophobic tube to the urinary catheter unit; attaching the hydrophobic tube to a drop counter inlet; attaching a drop counter outlet to a tubing valve, wherein the valve comprises: a valve body; a valve stem adapted to be inserted into the valve body where the valve stem has an inlet port; and a valve tip adapted to be inserted and fixed into the valve stem after a first end of the valve tip is positioned inside the valve body, wherein the hydrophobic tube is attached to a first end of the valve tip; attaching a second end of the valve tip to a urine collection bag tube, thereby causing the valve to open; connecting the collection bag tube to a urine collection bag, the catheter unit being adapted to continuously remove fluid from a bladder of the patient and to convey the fluid into the tube under a continuously negative fluid pressure; and conveying a column of fluid held by a meniscus of the column of fluid from the catheter to the collection bag via the valve without interruption, without manual manipulation of the tube or the collection bag, wherein a second end of the valve tip is adapted to hold the urine collection bag tube. 
     Also optionally the valve body further comprises a central bore, wherein the valve stem comprises a first portion having a greater area and a second portion having a smaller area, wherein a portion of the central bore is narrower than a second portion of the central bore, the narrower portion receiving the second portion of the valve stem and the second portion of the central bore receiving the first portion of the valve stem having the greater area. 
     Also optionally the first end of the valve tip contacts the second portion of the valve stem and causes the valve stem having the inlet port to move away from the valve body to open the valve. 
     Also optionally the second end of the valve tip is adapted to be inserted into the urine collection bag tube and is adapted to cause the first end of the valve tip to contact the second portion of the valve stem. 
     Also optionally the narrower portion of the central bore is adapted to be inserted into the urine collection bag tube with the second end of the valve tip, thereby preventing the valve from closing when the urine collection bag tube is attached to the valve. 
     Also optionally the second end of the valve tip is adapted to move away from the valve body upon removal of the urine collection bag tube and hence to cause the first end of the valve tip to cease to contact the second portion of the valve stem having the inlet port, thereby closing the valve. 
     Also optionally the valve stem and the central bore of the valve body each comprise complementary conical structures, such that when the tubing valve is closed, the conical structure of the valve stem having the inlet port is larger than the conical structure of the central bore, thereby blocking the inlet port. 
     According to at least some embodiments of the present invention, there is provided an urinary catheter system comprising: a catheter for insertion to the patient, a catheter tube, a tubing valve, and a urine collection bag having a urine collection bag tube, the catheter tube being connected to the catheter at one end of the tube, and the tube being connected to one end of the valve at an opposite end of the tube, and the valve being connected to the urine collection bag tube at an opposite end of the valve, wherein the tubing valve is adapted to permit fluid flow when the urine collection bag tube is connected and prevent fluid flow when the urine collection bag tube is removed. 
     Optionally the valve comprises: a valve body; a valve stem adapted to be inserted into the valve body where the valve stem has an inlet port; and a valve tip adapted to be inserted and fixed into the valve stem after a first end of the valve tip is positioned inside the valve body, wherein a second end of the valve tip is adapted to hold the urine collection bag tube. 
     Also optionally the valve body further comprises a central bore, wherein the valve stem comprises a first portion having a greater area and a second portion having a smaller area, wherein a portion of the central bore is narrower than a second portion of the central bore, the narrower portion receiving the second portion of the valve stem and the second portion of the central bore receiving the first portion of the valve stem having the greater area. 
     Also optionally the first end of the valve tip contacts the second portion of the valve stem and causes the valve stem having inlet port to move away from the valve body to open the valve. 
     Also optionally the second end of the valve tip is adapted to be inserted into the urine collection bag tube and is adapted to cause the first end of the valve tip to contact the second portion of the valve stem. 
     Also optionally the narrower portion of the central bore is adapted to be inserted into the urine collection bag tube with the second end of the valve tip, thereby preventing the valve from closing when the urine collection bag tube is attached to the valve. 
     Also optionally the second end of the valve tip is adapted to move away from the valve body upon removal of the urine collection bag tube and hence to cause the first end of the valve tip to cease to contact the second portion of the valve stem having the inlet port, thereby closing the valve. 
     Also optionally the valve stem and the central bore of the valve body each comprise complementary conical structures, such that when the tubing valve is closed, the conical structure of the valve stem having the inlet port is larger than the conical structure of the central bore, thereby blocking the inlet port. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Examples illustrative of embodiments of the disclosure are described below with reference to figures attached hereto. In the figures, identical structures, elements or parts that appear in more than one figure are generally labeled with the same numeral in all the figures in which they appear. Dimensions of components and features shown in the figures are generally chosen for convenience and clarity of presentation and are not necessarily shown to scale. Many of the figures presented are in the form of schematic illustrations and, as such, certain elements may be drawn greatly simplified or not-to-scale, for illustrative clarity. The figures are not intended to be production drawings. 
       The figures (Figs.) are listed below. 
         FIG. 1  is a schematic illustration showing a urinary catheterization kit including a valve in accordance with variations of the present invention. 
         FIG. 2  shows a detail of  FIG. 1  in accordance with variations of the present invention. 
         FIG. 3  is a schematic exploding view illustration showing a medical tubing valve in accordance with variations of the present invention. 
         FIG. 4  is a schematic cross section view of the valve of  FIG. 3  in a closed position, in accordance with variations of the present invention. 
         FIG. 5  is a schematic cross section view showing the valve of  FIG. 3  in an open position, in accordance with variations of the present invention. 
         FIG. 6  is a schematic cross section view showing the valve of  FIG. 3  in an open position allowing the flow of fluid, in accordance with variations of the present invention. 
         FIG. 7  is a schematic cross section view showing the valve of  FIG. 3  pulled into a closed position preventing the flow of fluid, in accordance with variations of the present invention. 
         FIG. 8  is a schematic cross section view showing the valve of  FIG. 3  pushed into an open position allowing the flow of fluid, in accordance with variations of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     In the following description, various aspects of a novel tubing valve adapted for various applications in both low and medium pressure applications will be described. For the purpose of explanation, specific configurations and details are set forth in order to provide a thorough understanding of the apparatus. 
     Although various features of the disclosure may be described in the context of a single embodiment, the features may also be provided separately or in any suitable combination. Conversely, although the disclosure may be described herein in the context of separate embodiments for clarity, the disclosure may also be implemented in a single embodiment. Furthermore, it should be understood that the disclosure can be carried out or practiced in various ways, and that the disclosure can be implemented in embodiments other than the exemplary ones described herein below. The descriptions, examples and materials presented in the description, as well as in the claims, should not be construed as limiting, but rather as illustrative. 
     Terms for indicating relative direction or location, such as “right” and “left”, “up” and “down”, “top” and “bottom”, “horizontal” and “vertical”, “higher” and “lower”, and the like, may also be used, without limitation. 
     Reference is now made to  FIGS. 1 and 2  that schematically illustrate a urinary catheterization kit  100  comprising a catheter  102 , a catheterization tube  104 , a receiving reservoir  108 , drop chamber  110 , the valve  120  of the present invention, a urine collecting bag attachment tube  130 , and a means for attachment  132  of the kit  100  to a urine collection bag  134 , in accordance with variations of the present invention. Valve  120  comprises valve body  122 , valve stem  124  and valve tip  126  as will be described in more detail below. 
     In accordance with the variation illustrated in this figure, valve  120  is positioned between drop chamber  110  and attachment tube  130 . The inlet of valve body  122  is preferably sized to allow the outlet of drop chamber  110  to be attached and held in place without the need for any retaining mechanism. In an optional embodiment with no retaining mechanism and an inlet diameter of up to 8 mm, the valve  120  will remain attached under medium or high pressures not exceeding approximately 4 bar. 
     The outlet of valve  120  is preferably sized to allow attachment tube  130  to be attached and held in place without the need for any retaining mechanism. 
     When used in a urinary catheterization system the closing as well as the opening of valve  120  is very intuitive and allows the removal and replacement of collection bag  134 , while preventing any contact between the medical team performing the replacement and the liquids in the collection bag, therefore keeping the near surrounding and medical staff clean. When collection bag  134  with attachment tube  130  is detached or otherwise removed from valve  120 , valve  120  is pulled close preventing the flow of liquid, and when collection bag  134  with tube  130  is pushed onto or otherwise connected to valve  120 , valve  120  is pushed open allowing the flow of liquid. This mechanism will be described in more detail below. 
     In accordance with one preferred variation of the invention, the valve may be used in urinary catheter arrangements as illustrated in detail in U.S. Pat Application No. 2010/0286667 (hereinafter: “667&#39;) incorporated herein in its entirety by reference and owned in common with the present application. The arrangement shown in  FIG. 1  is similar to the arrangements of the above reference and may optionally have the same or similar parameters as described below. 
     The arrangement illustrated in 667&#39; is arranged for enhanced continuous flow of urine in a catheterized patient and for preventing urinary tract infections in the patient. The arrangement generally comprises a catheter tube with a hydrophobic inner surface that is preferably polished, having an inner diameter of four to six millimeters, the tube being arranged to provide a continuously negative fluid pressure of less than 50 cm equivalent of water therein as a result of a meniscus forming at the beginning of a flow of urine from the bladder of the patient as a result of the narrowness of the tube and the repulsion of the urine from the hydrophobic surfaces of the tube, whereby during operation, the tube is always full of urine. As a result, a natural negative pressure builds up in the tube which serves to continuously suction urine from the bladder in a closed system, keeping the bladder empty resulting in a steady flow which does not allow for air spaces and bacterial build-up in the tube in the area adjacent the bladder. 
     Since the continuous negative pressure means that the tube is always full of urine, medical stuff may have difficulties replacing the urine bag when it is full. Without wishing to be limited in any way, valve  120  provides a solution to this problem and to allow replacement of a urine bag, such as urine collection bag  134 , or any other collected secreted fluids in a clean and sterile manner. When collection bag  134  with attachment tube  130  is detached from valve  120 , valve  120  closes and no flow through valve  120  is possible. In addition, in use, valve  120  prevents direct human contact with the urine or with other biohazardous materials as there is no need to touch any other part other than attachment tube  130  of collection bag  134  when replacing collection bag  134 . 
     Reference is now made to  FIG. 3  which is a schematic exploding view illustration showing valve  300  in accordance with variations of the present invention. Valve  300  generally comprises three components: a valve stem  310 , a valve body  330 , and a valve tip  340 . 
     Valve stem  310  preferably comprises an elongated hollow cylindrical portion; valve stem cylinder  312  attached to wider solid valve stem top  314 . Valve stem cylinder  312  preferably has a conical surface  316 . Valve stem  310  also preferably includes one or more stem inlet ports  318  that are situated below valve stem top  314 , and a valve stem outlet  320 . Conical surface  316  may optionally be a frustoconical surface. 
     Valve body  330  comprises a valve inlet chamber  332 , and a central bore  334 . Inlet chamber  332  is preferably shaped and sized so that its outer dimensions are slightly smaller than the inner dimensions of a drop chamber in a urinary catheter kit such as the drop chamber  110  described in  FIG. 1  above or optionally any other tubing or attachment mechanism in applications where the valve  300  is employed in order to allow the tight attachment of valve body  330  to said drop chamber, tubing or attachment. This attachment is further described below. 
     Central bore  334  is preferably cylindrical and hollow with an inner diameter slightly wider than the outer diameter of valve stem cylinder  312 . The inner surface  336  of central bore  334  preferably has a conical or frustoconical form, preferably shaped to match the conical or frustoconical surface  316  on the outer surface of stem cylinder  312 . These dimensions preferably allow the insertion of valve stem  310  into valve body  330  so that the conical surface  316  of stem cylinder  312  fits snugly against the conical inner surface  336  of central bore  334 . 
     Valve tip  340  preferably includes a tube attachment part  342 , a stem insertion part  344  and valve outlet port  346 . Tube attachment part  342  is preferably conically shaped and sized so that its outer dimensions are the same or slightly wider than the inner dimensions of an attachment tube in a urinary catheter kit such as the attachment tube  130  described above or optionally any other tubing or attachment mechanism in applications where the valve  300  is employed in order to allow the tight attachment of the valve to said attachment tube, or other tubing or attachment. An outermost dimension of the tube attachment part  342  is preferably wider than the diameter of central bore  334  and forms a radially enlarged shoulder  343 . 
     Stem insertion part  344  is preferably sized to so that its outer diameter is slightly smaller than valve stem outlet  310 . This enables stem insertion  344  of valve tip  340  to be attached to stem outlet  310  optionally using adhesive or ultrasonic welding so as to permanently fix it after insertion. 
     Reference is now made to  FIGS. 4 and 5  that illustrate valve  300  in a closed and open position respectively, in accordance with variations of the invention. 
       FIG. 4  is a schematic cross section view of valve  300  of  FIG. 3  in a closed position, in accordance with variations of the present invention. 
     As shown, the assembled valve preferably includes valve stem  310  inserted into valve body  330 . Valve stem outlet  310  is attached to stem insertion  344  of valve tip  340 . The assembled valve stem and valve tip can move up and down within the valve body. 
     When valve  300  is in a closed position, inlet port  318  is sealed against the inner surface  336  of central bore  334 . Conical surface  316  of valve stem  310  is pressed against conical inner surface  336  of central bore  334  creating a light interference fit that will hold the valve closed. The conical shape of the interference fit allows the fit to be broken with relative ease. When the valve is in a closed position, a gap  410  exists between valve body  330  and the tube insertion part  342  of valve tip  340 . 
       FIG. 5  is a schematic cross section view showing the valve  300  of  FIG. 3  in an open position, in accordance with variations of the present invention. When valve  300  is in an open position, assembled valve stem  310  and valve tip  340  together move upward until the radially enlarged shoulder abuts against a bottom surface  345  of the valve body  330 , closing gap  410 . Inlet port  318  is not blocked by the inner surface  336  of central bore  334 . 
     Reference is now made to  FIGS. 6, 7, and 8  that respectively illustrate fluid flow through valve  300  in an open position, valve  300  pulled into a closed position preventing fluid flow, and fluid flow through valve  300  pushed into an open position, in accordance with variations of the invention. 
     As shown, the valve inlet chamber  332  is preferably attached to a source of fluid, which may optionally include the drop chamber  110  of catheter assembly  100  of  FIG. 1  or any other source of fluid depending on the application in which the valve is used. The attachment is made by sliding the outlet attachment  610  of the fluid source over the outside surface of the valve inlet chamber  332 . As described above, the size and shape of inlet chamber  332  preferably matches that of the outlet attachment  610  in use. 
     The outlet of valve  300  is preferably attached to the destination of the fluid flow which may optionally include the attachment tube  130  of catheter assembly  100  of  FIG. 1  or any other fluid destination depending on the application in which the valve is used. The attachment is made by sliding the attachment tube  620  of the fluid destination over the outside surface of the tube attachment port  342  and the central bore  334 . As described above, the size and shape of attachment port  342  preferably matches that of the tube attachment  620  in use. The conical shape of attachment port  342  preferably eases the process of deforming tube  620  when sliding it onto the valve. 
       FIG. 6  is a schematic cross section view showing the valve  300  of  FIG. 3  in an open position, in accordance with variations of the present invention. When valve  300  is in an open position, fluid  510  that has accumulated in valve inlet chamber  332  of valve body  330  flows through inlet port  318  and stem cylinder  312  of valve stem  310  before exiting the valve through outlet port  346  of valve tip  340 . Tube  620  holds valve  300  in an open position by gripping the outer surface of central bore  334  and the outer surface of valve tip  340 . 
       FIG. 7  is a schematic cross section view showing the valve  300  of  FIG. 3  pulled into a closed position, in accordance with variations of the present invention. As tube  620  is pulled off the valve, valve tip  340  is pulled downward due to the friction against tube attachment part  342 . Valve stem  310  which is attached to valve tip  340  is also pulled down causing stem inlet ports  318  to be sealed against the inner surface  336  of central bore  334  and preventing the further flow of fluids  510  accumulated in inlet chamber  332  through the valve. Conical surface  316  of valve stem  310  is pressed against conical inner surface  336  of central bore  334  creating a light interference fit that holds the valve closed. 
       FIG. 8  is a schematic cross section view showing the valve  300  of  FIG. 3  pushed into an open position, in accordance with variations of the present invention. When an attachment tube  620  is forced onto the valve  300  by pushing it over the conical surface of attachment part  342  of valve tip  340 , the valve tip is pushed upward. Valve stem  310  which is attached to valve tip  340  is also pushed upward breaking the light interference fit between conical surface  316  of valve stem  310  and conical inner surface  336  of central bore  334 . Stem inlet ports  318  are pushed out of the central bore  334  allowing fluid  510  that has accumulated in inlet chamber  332  to once more enter inlet ports  318  and stem cylinder of valve stem  310 , before exiting the valve through outlet port  346  of valve tip  340 . Tube  620  holds valve  300  in an open position by gripping the outer surface of central bore  334  and the outer surface of valve tip  340 . 
     The valve of the present invention aims to allow replacement of a urine bag or any other collected secreted fluids in a clean and sterile manner. When the tube is pulled off the valve of the invention, the valve closes and no flow through the valve is possible. In addition, in use, the valve prevents direct human contact with urine or with other biohazardous materials as there is no need to touch any other part other than the outer tube  620  of the collecting bag when replacing it. 
     No mechanism is otherwise involved in opening or closing the valve aside from sliding the attachment tube  620  on or off, thus making the mechanism provided herein simple, cheap and reliable. In addition, no special fitting or finishing is required to create the interference fit as this is provided by the matching conical inner surfaces making molding quite easy. 
     It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative examples and that the present invention may be embodied in other specific forms without departing from the essential attributes thereof, and it is therefore desired that the present embodiments and examples be considered in all respects as illustrative and not restrictive, reference being made to the appended claims, rather than to the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. 
     It should be clear that the description of the embodiments and attached Figures set forth in this specification serves only for a better understanding of the invention, without limiting its scope. It should also be clear that a person skilled in the art, after reading the present specification could make adjustments or amendments to the attached Figures and above described embodiments that would still be covered by the present invention. 
     It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination.