MXPA98002245A

MXPA98002245A - Tightening valve that responds to the tens

Info

Publication number: MXPA98002245A
Application number: MXPA/A/1998/002245A
Authority: MX
Inventors: S Osborne Robert; L Buck Bradford; S Fleming Matthew; E Patton William; E Alexander Kathryn; R Wilson Grant; J Piontek Carl; M Harris Jeremy; F Lyon William
Original assignee: Abbott Laboratories
Priority date: 1995-09-21
Filing date: 1998-03-20
Publication date: 1998-11-12

Abstract

A tension-responsive clamping valve is formed of a combination of an elastically flexible clamping valve member, and a length of flexible tubing having a section which is to be automatically closed when distorted to the point of tightening or twisting, and in this way it closes to the chamber when the distorted section is not under a longitudinal tension. The clamping valve element is longitudinally associated with the pipe section, and preferably has two end portions connected by a stem portion. The end portions are attached to the pipe section at longitudinally spaced points of the flexible pipe, such that the length of the covered section is much longer than the shank portion of the valve member of the tightening valve element. If the resistance the elastic performance of the shank portion is greater than the bend resistance of the flexible piping, the covered section of the flexible piping will bend up to the point of occlusion when the section is not under tension, but will allow the passage of fluid when the longitudinal tension is applied without grip

Description

TIGHTENING VALVE THAT RESPONDS TO THE VOLTAGE FIELD OF THE INVENTION The invention relates in general to valves that automatically close the chamber of a flexible pipe or hoses, and respond to the voltage, opening only when the valve section of the pipe or the hose is under sufficient longitudinal tension , and closing when no voltage is applied. The invention relates more specifically to valves that tighten or twist the flexible pipe or hose to close it and achieve a valve effect.

BACKGROUND OF THE INVENTION In a number of situations, it would be desirable to have a simple and inexpensive valve that closes the chamber of a flexible tube or hose automatically, so as to stop a flow of liquid through the tube or hose. , normally under a low or moderate pressure, when a previously determined condition presents itself until an additional flow is desired, and that nevertheless has obtained the renewed flow easily. For example, in the administration of an enteral or parenteral fluid to a patient, with a rotating peristaltic pump, it is very important that the fluid flow is regulated. If the fluid transfer device used with the peristaltic pump accidentally gets dislodged from the pump housing, so that the pump rotor does not regulate the flow of fluid, it would be very desirable to have some element that automatically closes the flow of fluid. until the problem is observed and the fluid transfer apparatus is reinstalled. Different valve mechanisms have been used to control the flow of air, as well as liquids, but it seems that up to now no simple and economical valves have been devised that are suitable for use in an establishment where it is important to have a regulated liquid flow continuous, but an automatic closing if the flow becomes deregulated. In the case of fluid transfer devices used to administer intravenous or parenteral fluids to a patient's body, the cost of this precaution valve is an important consideration, since the devices are used only once and discarded. U.S. Patent No. 2,444,449 discloses a valve configuration for the inflation of inflatable recipients by respiration, such as life preservers and air cushions having a soft rubber valve stem that is adapted to bend on itself to retain air in the container. Two elastic members are each joined by a respective band with the base and with the free end of the valve stem in separate holding locations, the elastic members being joined by a "maintainer" at about half the length of the rod of the valve. The valve. By appropriate selection of the material from which the valve stem is formed, and from the elastic members with an appropriate level of resistance to elastic performance, the valve stem will be able to erect itself erect without help against the pull of the elastic members. , once it is straightened with some compression tightening to remove the twist. When it is desired to close the valve stem, it is simply bent manually, and the elastic members will remain bent. Accordingly, it can be seen that this valve device does not provide a continuous regulated liquid flow through a flexible pipe with an automatic closing of the valve if the liquid flow were to be deregulated. U.S. Patent No. 2,002,835 discloses a valve configuration for controlling the discharge of an airified or gasified liquid from a bottle or other closed container from which the liquid will "siphon" when a tube is opened. discharge from the container. The valve configuration is constituted by a hollow closing element in the form of a kind of stopper for a bottle or flask. A flexible discharge tube extends up from near the bottom of the bottle or vial, and through the stopper and part of the way through a tubular extension of heavy, hollow, flexible and erect wall of the stopper. The tubular extension comfortably surrounds and extends beyond the end of the discharge tube. Approximately half the length of the tubular extension, the walls are thinner, and the tubular extension easily bends over its own weight, and bends the discharge tube with it sufficiently to tighten or twist the discharge tube and close it, precluding the download. The inclined end of the tubular extension is easily lifted in a manual manner to allow the gasified liguid to be discharged under pressure, and by allowing the end to drip again, the discharge tube is bent sufficiently to close the flow of liquid. This device, then, is not an automatic operation. US Patents Nos. 3,976,277 and 2,957,607 disclose an apparatus for dosing liquids through a flexible pipe, where solenoid-operated clamping tube elements are used to compress the flexible pipe, in order to control the passage of the liquid through it. The valve is not automatic by itself, requiring a mechanical element that must be activated to tighten. United States Patent Number 4,063,706 discloses a clamping valve formed of a wire helix and a flexible tube for controlling the flow of the liquid through the flexible tube. The control is done manually, and the valve does not respond to tension. The Patent of the United States of North America Number 4,620,564 discloses a device for regulating the flow of liquid through a tube, by mechanically twisting the tubing, the tubing actually having therein formed a plurality of substantially parallel flow passages which close when the tubing is twisted. The operation does not respond to the flow velocity or the longitudinal tension on the tube. The British Patents Numbers 16,321; 634,975 and 1,149,915, disclose valves for closing tubes or other structures with the tube twisting mechanically, or a type of iris mechanism such as a chamber opening control. Patents of the United States of North America Nos. 3,995,780; 2,555,490; 4,109,486; 2,117,071 and 5,072,855, each discloses some form of valve that responds to pressure, which controls the discharge of a paste from some kind of collapsible container or tube, when pressure is applied mechanically, or in some cases manual pressure is applied.

SUMMARY OF THE INVENTION The clamping valve which responds to the tension of the invention is formed of a combination of an elastically flexible valve element, and a section of flexible tubing having a section to be closed, i.e., to occlude, when twisting, bending or bending, or otherwise deforming automatically to the point that the twisting or tightening closes the pipe chamber when the valve is not under tension. The valve element is associated with the section of the flexible pipe section to be closed when it is not under tension. In a preferred embodiment, the valve member is attached to the outer surface of the flexible pipe section, and has end portions connected by a middle portion in the shape of a rod portion. The end portions are attached to the flexible tubing at points spaced longitudinally of the section, such that the length of the section encompassed between the spaced points is much longer than the rod portion of the valve element, and of a length suitable for bending or twisting sharply, and tightening to close the pipe when the end portions of the valve elements are pulled to approach each other by the rod portion when the pipe is not under tension. Under tension, the portion of the rod is stretched, and the pipe is left untightened or untwisted, enough to allow the passage of fluid. According to one aspect of the invention, a tension-responsive clamping valve is provided, which comprises: an assembly of an elastically flexible clamping valve member, and a flexible pipe section having a chamber and a section that is going to be closed reversibly like a valve; the clamping valve element being fixedly associated longitudinally with the section of the flexible pipe section, and being able to distort the section up to the tightening point of the chamber of the section where it closes, when the flexible pipe is not under tension , while allowing the chamber to open when the flexible tubing is under tension, enough to lengthen the clamping valve element, and to at least partially undo the distortion of the flexible tubing section. According to another aspect of the invention, there is provided a tension-responsive clamping valve, which comprises: an assembly of an elastically flexible clamping valve member, and a flexible pipe section having a chamber and a section that is going to be closed reversibly like a valve; the clamping valve member comprising a flexible elastic polymeric material, and having a pair of tubular segment end portions joined by a rod portion, the tubular segment end portions being telescopically assembled, the flexible tubing and the element being of tightening valve capable of distorting the flexible pipe section to the point of tightening the chamber of the flexible pipe section to close it, when the flexible tubing is not under tension, while allowing the chamber to open when the flexible tubing is under sufficient tension to lengthen the clamping valve element, and to at least partially undo the distortion of the flexible tubing section . According to another aspect of the invention, there is provided a tension-responsive clamping valve, which comprises: an assembly of an elastically flexible clamping valve member, and a flexible pipe section having a chamber and a section that is going to be reversibly closed like a valve; the clamping valve member comprising a flexible elastic polymeric material, and having a substantially planar rectangular rod portion connecting the substantially planar rectangular end portions, each of which has a concave surface adapted to fit comfortably against a external cylindrical surface of the flexible pipe, and is connected to it, the tightening valve being able to distort the section of flexible pipe to the point of tightening the chamber of the flexible pipe section to close it when the flexible pipe is not under tension, while the chamber is allowed to open when the flexible tubing is under sufficient tension to elongate the clamping valve element and to at least partially undo the distortion of the flexible tubing section. According to another aspect of the invention, there is provided a tension-responsive clamping valve, which comprises: an assembly of an elastically flexible clamping valve member, and a flexible pipe section having a chamber and a section that is going to be closed reversibly like a valve; the clamping valve member comprising a flexible elastic polymeric material, and forming in the configuration of the capital letter "I" from a flat sheet, the end portions of the "I" being wrapped substantially around the flexible tubing and bonding with it, the valve element being able to distort the flexible pipe section to the point of tightening the chamber of the flexible pipe section to close it when the flexible pipe is not under tension, while allowing the chamber to open when the flexible pipe is under a sufficient tension to elongate the clamping valve element and at least partially undo the distortion of the flexible pipe section.

According to another aspect of the invention, a tension-responsive clamping valve is provided, which comprises: an assembly of an elastically flexible clamping valve member, and a flexible pipe section having a chamber and a section that will be reversibly closed like a valve; the clamping valve member comprising a flexible elastic polymeric material, and having arcuate end portions that are joined by a stem portion having a foraminated cross-section, each of the end portions having a concave surface that engages with , and is connected to, the outer surface of the flexible pipe, the tightening valve element being capable of distorting the flexible pipe section to the point of tightening the flexible pipe section chamber to close it when the flexible pipe is not under tension, while allowing the chamber to be opened when the flexible tubing is under sufficient tension to elongate the clamping valve member and at least partially to undo the distortion of the flexible tubing section. According to another aspect of the invention, a tension-responsive clamping valve is provided, which comprises: an assembly of an elastically flexible clamping valve member, and a flexible pipe section having a chamber and a section that is going to be closed reversibly like a valve; the clamping valve element being a piece configured as a semi-cylindrical jacket of a flexible elastic polymeric material, each end of the clamping valve element joining the flexible pipe, the clamping valve element being capable of distorting the section of the clamping valve. flexible tubing to the point of tightening the chamber of the flexible tubing section to close it when the flexible tubing is not under tension, while allowing the chamber to be opened when the flexible tubing is under sufficient tension to lengthen the tubing element. tighten and undo at least partially the distortion of the flexible pipe section. According to another aspect of the invention, a tension-responsive clamping valve is provided, which comprises: an assembly of an elastically flexible clamping valve member, and a flexible pipe section having a chamber and a section that is going to be closed reversibly like a valve; the clamping valve member comprising a flexible elastic polymeric material, the clamping valve member having a pair of tubular segment end portions joined by a stem portion, the end portions being molded around the flexible tubing, and the other end portion being telescopically placed around the flexible tubing, and separated from the first end portion by a collocation collar, which is molded as an insert around the flexible tubing, the clamping valve element being capable of distorting the section of flexible tubing to the point of tightening the chamber of the flexible tubing section to close it when the flexible tubing is not under tension, while allowing the chamber to open when the tubing is under sufficient tension to elongate the valve element of tightening and undoing at least partially the distortion of the section of flexible pipe. According to another aspect of the invention, a tension-responsive clamping valve is provided, which comprises: an assembly of an elastically flexible clamping valve member, and a flexible pipe section having a chamber and a section that is going to be closed reversibly like a valve; the clamping valve member comprising a flexible elastic polymer material, and having a pair of closed loop end portions joined by a portion of the rod, each end portion being telescopically placed around the flexible tubing, the clamping valve element being capable of distorting the flexible pipe section to the point of tightening the chamber of the flexible pipe section to close it when the flexible pipe is not under tension, while allowing the chamber to be opened when the The flexible pipe is under sufficient tension to lengthen the clamping valve element and to at least partially undo the distortion of the flexible pipe section. According to another aspect of the invention, a tension-responsive clamping valve is provided, which comprises: an assembly of an elastically flexible clamping valve member, and a flexible pipe section having a chamber and a section that is going to be reversibly closed like a valve; the clamping valve element being a sharply bent part of a highly elastic spring material molded into the wall of the flexible pipe, the clamping valve element being capable of distorting the section of flexible pipe to the point of tightening the chamber of the pipe. flexible tubing section to close when the flexible tubing is not under tension, while allowing the chamber to open when the flexible tubing is under sufficient tension to elongate the clamping valve element and at least partially undo the distortion of the section of flexible pipe. According to another aspect of the invention, a tension-responsive clamping valve is provided, which comprises: an assembly of an elastically flexible clamping valve member, and a flexible pipe section having a chamber and a section that is going to be closed reversibly like a valve; the clamping valve element being a sharply bent clamp of a highly elastic spring material bonded to the outside of the wall of the flexible pipe, the clamping valve element being capable of distorting the section of flexible pipe to the point of tightening the chamber of the flexible tubing section to close it when the flexible tubing is not under tension, while allowing the chamber to open when the flexible tubing is under sufficient tension to lengthen the clamping valve member and to at least partially undo the distortion of the flexible pipe section.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of a clamping valve in accordance with the invention, which consists of a spring-loaded valve element together with a length of flexible pipe on which the element of pressure is installed. valve. Figure 2 is a perspective view of the clamping valve element of Figure 1. Figure 3 is a side view of a length of flexible tubing and a flexible clamping valve element for telescopically assembling therewith, to make a tightening valve, the portions of the flexible pipe and the tightening valve element being identified to illustrate the relative dimensions. Figure 4 is a side view of a clamping valve made of the components shown in Figure 3. Figure 5 is a front elevational view of a rotating peristaltic pump and an assembled fluid transfer apparatus together with a valve member. flexible tightening system telescopically installed on the flexible tubing of the fluid transfer apparatus adjacent to the pump rotor, to make the tightening valve according to the invention, the fluid transfer apparatus being connected at the inlet end thereof with a supply container of a nutritious enteral product, and at its discharge end with a feeding tube that extends to the stomach of a patient whose abdomen is shown in a fragmentary view, partially separated in sections and in section. Figure 6 is a perspective view of a fluid transfer apparatus for the enteral or parenteral administration of a fluid, using a rotating peristaltic pump, having a clamping valve according to the invention installed on the flexible tubing of the transfer apparatus of the fluid, with the valve closed in the absence of tension on the flexible pipe. Figure 7 is a side view of the fluid transfer apparatus of Figure 5, with tension on the flexible pipe, through which the clamping valve is opened.

Figure 8 is a front elevational view of the combination of peristaltic pump and fluid transfer apparatus of Figure 7, having a clamping valve adjacent to the pump rotor, and with the parts of the flexible tubing of the apparatus transfer of truncated and shortened fluids. Figure 9 is a perspective view of the combination of peristaltic pump and fluid transfer apparatus of Figure 8. Figure 10 is a fragmentary view of a pendant supply container for an enteral or parenteral fluid, shown connected to the end of an assembled fluid transfer apparatus with a rotating peristaltic pump of the prior art, and having a clamping valve of the invention adjacent to the pump rotor. Figures 11 and 12, respectively, are perspective views of a different clamping valve formed of a length of flexible tubing, and of the clamping valve element therefor, this clamping valve element not regulating a telescopic assembly. Figures 13 and 14, respectively, are perspective views of a different clamping valve, and of the clamping valve member therefor, the clamping valve element of a telescopic assembly not requiring.

Figures 15 and 16 are perspective views similar to Figures 13 and 14, respectively, of a different clamping valve, and of the clamping valve member therefor, also not regulating this clamping valve element of a telescopic assembly. Figure 16A is a view of the surface of the tightening valve element seen in Figure 16, which faces the flexible pipe in the assembled tightening valve of Figure 15. Figures 17 and 18 are similar perspective views to Figures 15 and 16, respectively, of a different clamping valve, and of the clamping valve element for the same, nor does this clamping valve element require a telescopic assembly. Figure 19 is a perspective view of a length of flexible tubing having a clamping valve partially assembled therewith with yet another form of clamping valve member, and with a collar on the flexible tubing to serve as an advancer for position or a stop for the installation of the second tubular segment end portion of the tightening valve element. Figure 20 is a perspective view of the clamping valve in Figure 19 fully assembled, with the part of the flexible pipe between the tubular segment end portions of the clamping valve element bent to tighten back on themselves , squeezing the flexible tubing to close it. Figure 21 is a perspective view of the flexible tubing and the clamping valve formed therefrom, illustrated in Figure 20, with the flexible tubing under a sufficient longitudinal tension for the clamping valve to open to the fluid flow. Figure 22 is a side view of another elastic clamping valve element suitable for assembling with a length of flexible tubing to form a clamping valve in accordance with the invention. Figure 23 is a side view of another clamping valve made of the valve element of Figure 22, and a section of flexible tubing, shown truncated, the flexible tubing not being under tension, and bending and tightening between the end portions of the tubing. tightening valve element as a result of the elastic pull of the shank portion. Figure 24 is a side view of a clamping valve formed using the clamping valve element of Figure 22 and a flexible pipe, shown truncated, with the ends of the flexible pipe under tension by means not shown, in such a way that the elastic pull of the shank portion of the tightening valve element is being exceeded, and the flexible piping is sufficiently straight for a continuous flow of the valve through the valve. Figure 25 is a sectional view of another form of tension-responsive clamping valve, wherein a bent spring wire capable of bending the flexible tubing sufficiently for occlusion is embedded in the wall of a section of the tubing flexible. Figure 26 is a sectional view taken along line 26-26 of Figure 25, showing the bent spring wire molded into the wall of the pipe. Figure 26A is a sectional view similar to the Figure 26, showing another form of the type of tightening valve spring wire illustrated in Figure 25, wherein the wire is molded or longitudinally bonded along the outside of the flexible pipe. Figure 27 is a side view of another form of clamping valve, wherein the clamping valve element, when properly fixed in place over a length of flexible tubing, causes the flexible tubing to be twisted sufficiently to take place the occlusion, when the flexible tubing is not under tension. Figure 28 is a perspective view of the front and side of the apparatus for the clamping valve assembly of Figures 1 and 4. Figure 29 is a perspective view of the back and side of the assembly apparatus of FIG. Figure 28. Figure 30 is a front elevational view of the assembly apparatus of Figure 28. Figure 31 is a highly amplified fragmentary view of the portion of Figure 30 enclosed in a circle by a dotted line. Figure 32 is a vertical sectional view of the assembly apparatus, taken along line 32-32 of Figure 30. Figure 33 is a perspective view separated into parts of the components of an assembly apparatus, such as the apparatus of Figure 28, with a corner of the base plate cut off for illustration purposes. Figure 34 is a highly amplified perspective view of an ejector block that can be used as a part of a subassembly identified by the reference character 330 in Figure 33. Figure 35 is a highly magnified perspective view of another ejector blog that can be used in a modification of the sub-assembly identified by reference character 330 in Figure 33. Figure 36 is an amplified perspective view separated into parts of some of the sub-assembly components identified by the character reference 330 in Figure 33, which includes the ejector blog of Figure 34. Figure 37 is an amplified perspective view separated into parts of all components of the subassembly identified by the reference character 330 in Figure 33, with the components shown in Figure 36 already assembled together. Figure 38 is a highly magnified perspective view of an "L" -shaped extensor finger element, showing the guide pin extending laterally from the leg portion. Figure 39 is a highly amplified perspective view, partially separated in parts, of the subassembly identified by the reference character 330 in Figure 33, in the assembly process. Figure 40 is a highly amplified perspective view of the subassembly identified by the reference character 330 in Figure 33. Figure 41 is a perspective view of the inverse or internal face of the cover plate. Figure 42 is a perspective view of the assembly apparatus with the components of a tightening valve shown in a detached view relationship in parts about to be assembled, using the assembly apparatus. Figure 43 is a fragmentary perspective view of the assembly apparatus shown, with a first tubular segment end portion of the clamping valve member oriented to be placed on, ie, around, the fingers of the finger-expander elements. Figure 44 is a view similar to Figure 43, with the first tubular segment end portion of the clamping valve member slid over the group of extenders to begin the assembly process. Figure 45 is a vertical sectional view of the assembly apparatus as shown in Figure 32, but with the first tubular segment end portion of the pressure valve member positioned on the extension fingers as in Figure 44. Figure 46 is a fragmentary perspective view similar to Figure 44, showing the first tubular segment end portion of the tightening valve element shown in Figure 44, stretched to open radially, in order to receive through it the stretch of flexible tubing, on which the tightening valve element is to be telescopically assembled. Figure 47 is a fragmentary sectional view of the assembly apparatus, and of the first tubular segment end portion stretched from the clamping valve member shown in Figure 46, and with the length of flexible tubing inserted in the apparatus on the central guide rod and through the group of extensor fingers.

Figure 48 is a front elevation of the portion of the assembly apparatus encompassed by the cover plate at the point of the assembly process illustrated in Figures 46 and 47. Figure 49 is a fragmentary sectional view of the assembly apparatus with the first tubular segment end portion of the tightening valve element relaxed on the flexible pipe section, and with the ejector piston moved forward. Figure 50 is a front elevation of the portion of the assembly apparatus encompassed by the cover plate at the assembly process point illustrated in Figure 49. Figure 51 is a fragmentary perspective view of the assembly apparatus, closely similar to that of FIG. that of Figure 42, but adapted with a longer ejector block for the next stage of assembly of a clamping valve assembly with the second tubular segment end portion of the clamping valve member oriented to be placed on, ie, around, the extensor fingers, and with the forward end of the flexible pipe section temporarily bent aside. Figure 52 is a view similar to Figure 51, showing an additional step in the next step of manufacturing a clamping valve assembly, wherein the second tubular segment end portion is being placed on the flexible pipe section . Figure 53 is a fragmentary sectional view of the assembly apparatus with the tubular segment end portion of the pressure valve member stretched to open, and the end portion of the flexible tubing bent, as seen in Figure 52, and inserted into the assembly apparatus on the central guide rod and through the group of extenders. Figure 54 is a fragmentary sectional view of the assembly apparatus similar to Figure 53, but with the second tubular segment end portion of the tightening valve element relaxed around the length of flexible tubing, and the ejector piston moved forwardly. .

DETAILED DESCRIPTION OF THE INVENTION For the purposes of the specification and the claims, it is understood that a tightening valve that responds to the tension is the assembly of a section of a length of flexible pipe with a valve element of tightening, in where the tightening valve can bend or bend the flexible pipe section enough to close its chamber, to prevent the passage of fluid through it, when the section or pipe of which it is part, is not under tension enough to stretch or straighten the clamping valve element.

In Figures 1 and 4 a preferred example embodiment of a clamping valve according to the invention is illustrated. The clamping valve is formed of a clamping valve element, such as the clamping valve element 80 shown in Figures 2 and 3, and a section of a flexible pipe section 49, illustrated in Figures 1 and 4 as part of the tightening valve. The clamping valve member 80 is formed of a flexible elastic polymeric material, such as a silicone rubber, and is telescopically assembled and longitudinally extended along a section 75 of the flexible pipe 49 when forming the clamping valve. The clamping valve member 80 is seen to have tubular segment end portions 82, 83 joined by a stem portion 84. The clamping valve member 80 can be made by flattening a short piece of flexible tubing, and stamping or cutting about half or more of the width along the longitudinal middle section, leaving a substantially semi-cylindrical short jacket-like rod portion 84, which has approximately one third of the total length of the valve member 80, and two portions of shortened tubular segment end 82, 83 of approximately equal length. The rod portion 84 should be approximately the same length as each of the tubular segment end portions 82, 83.

A clamping valve element, such as the clamping valve member 80, and a number of other similar non-metallic clamping valve elements of the kind described herein, is formed of a flexible elastic polymeric material, such as a silicone rubber. Other tightening valve elements are formed of a spring material, such as spring steel wire or a similar spring-cured polymer resin. The flexible polymer tubing with which the clamping valve member is assembled is a tubing made of a silicone rubber or other similarly flexible polymeric material. When the clamping valve member 80 is telescopically installed on the section 75 of a length of flexible tubing, this flexible tubing 49, which has an external diameter at least as large as the internal diameter of the tubular segment end portions 82, 83, and with the tubular segment end portions positioned further apart along the section 75 of the flexible tubing than the length of the rod portion 84 by virtue of which the tubing section is bent during assembly with the element. of valve, with a length ratio of about 4: 1, then the rod portion 84 of the valve element 80 has a sufficiently large elastic performance module to elongate the bend module of the flexible pipe 49, and the valve element tightening 80 will direct upwardly the ends of the covered section 75 of flexible tubing 49, and will bend and twist it, such that the wall of the tubing 49 The tubing is tightened as seen in Figures 1 and 4, blogging any fluid flow through it, unless tension is applied to straighten the flexible tubing section 75 enough to open the chamber 49a for the flow of the tubing. fluid through it. Briefly stated, the clamping valve responsive to the tension of the present invention is an assembly of an elastically flexible clamping valve member and a flexible pipe section having a chamber and a section that is to be reversibly closed. as a valve. The clamping valve element is fixedly associated longitudinally with the section of flexible pipe, and is capable of distorting the stretch of flexible pipe to the point of tightening the chamber of the flexible pipe section to close it when the flexible pipe is not under tension . However, the tension-responsive valve assembly allows the chamber to open when the flexible tubing is under sufficient tension to elongate the clamping valve element and to at least partially undo the distortion of the flexible tubing section. . The relative lengths are very important. The covered section of the flexible tubing must be long enough for the rod portion of the clamping valve element to exert a substantial longitudinal pull between the ends of the covered tubing section 75, but not so long as to make the tubing section covered does not bend sharply enough in half for its occlusion. If it is too long or too short, the covered pipe section will simply make a light circuit, or will form a simple arc, respectively, under the pull of the shank portion of the tightening valve element. Since the resistance to elastic performance of the shank portion of the tightening valve element is greater than the resistance to bending of the flexible piping, the covered section of the flexible piping will bend to the point of occlusion, when the flexible piping It is not under tension, but will allow the passage of fluid while the longitudinal tension is being applied to untwist it. Referring now to Figures 3 and 4, the clamping valve element 80 is installed on a length of flexible pipe 49, with the tubular end portions 82., 83, separated by a distance "C" along the flexible pipe 49, while the portion of rod 84 assumes a length very close to "D" when it is not under tension, the length "D" being sufficiently shorter The length "C" for bending and tightening the pipe to close it when not under tension sufficient to stretch the rod portion 84. As an example, with a flexible silicone rubber pipe of 0.33 centimeters (0.131 inches) in diameter internal, 0.51 centimeters (0.199 inches) of external diameter, and a wall thickness of approximately 0.086 inches (0.034 inches), and with a tightening valve element 80 cut with trogue from the same type of pipe that has the inner edges of the tubular end portions 82, 83 separated by a stem portion of approximately 0.51 centimeters (0.199 inches) in length when not under tension, i.e., when not stretched, the edges s of the tubular end portions 82, 83 should be separated by a distance of approximately 2.0 centimeters (0.80 inches) when installed telescopically on the length of flexible tubing 49, in order to obtain a desired tightening or twisting to block the flow of fluid. For a given elastically flexible pipe, the dimensions are very important to obtain the desired valve action with a good opening and a sufficiently positive closure. The length of the pipe section encompassed 75 between the tubular segment end portions of the clamping valve element is especially important to obtain a sufficient bend to have a sharp bend, but not so much as to form a looser circuit. This can be determined empirically by trial and error for a flexible pipe of a given size made of a material with a given modulus of elasticity. As indicated, an important use of the tightening valve of the invention is a precaution against the unregulated flow of enteral or parenteral fluid, in the case of accidental or unintentional disassembly, of a fluid transfer apparatus from a pump rotating peristaltics. For example, as shown in Figure 5, a liquid enteral nutrient fluid is being drawn from a hanging supply container 91 to a fluid transfer apparatus 42 mounted on the housing 41 of a peristaltic pump, and is being transferred to a feeding tube 69 which extends through a gastrostomy 70 into the stomach 74 of a patient. The clamping valve element 80 seen in Figures 6 and 7 has been assembled with a length of flexible tubing 49 forming part of a fluid transfer apparatus 42, which can be used with a rotating peristaltic pump as shown in Figures 5, 8 and 9. A first section of flexible tubing 39 of the fluid transfer apparatus can be connected to, or is integral with, a supply container 91, and a third section of flexible tubing 64 of the transfer apparatus. of fluid can be connected to, or is integral with, a device for the transfer of fluid into the body of a patient. A second length of flexible tubing 49 extends between the outlet of a drip chamber 43 and a retainer / connector element 56 that fits into the respective support retaining recesses or recesses, 44, 55 in the pump housing 41. In an intermediate manner, the flexible pipe section 49 extends around the peristaltic rotor 52 of a peristaltic pump, and the section 75 of the pipe section 49 of this assembly, with a tightening valve element 80, forms a valve of tighten that is on the downstream side of the peristaltic rotor 52 when the fluid transfer apparatus 42 is mounted on the housing 41 of the pump. Preferably, the first and third sections of pipe 39, 64 are made of polyvinyl chloride (PVC), and the second section of pipe 49 is made of an elastically flexible silicone rubber. The flexible pipe 41 of the fluid transfer apparatus 42 is not under tension before being mounted on a pump housing, such that, as illustrated in Figure 6, the rod portion 84 of the tightening valve member 80 pulls the respective tubular segment end portions 82, 83 sufficiently close together, so that the section 75 of the flexible tubing 49 enclosed between the tubular segment end portions is bent and tightened or twisted to the occlusion point of the defined chamber by the wall of the pipe. The length of flexible tubing 49 of the fluid transfer apparatus 42 is illustrated in Figure 7, as would appear when mounting the fluid transfer apparatus on a pump housing, and a length of flexible tubing extending between the fluid chamber. drip 43 and the retention element / connector 56 is delivered in an intermediate manner around the peristaltic rotor 52 of the peristaltic pump. Accordingly, the tension on the flexible pipe 49 stretches the rod 84 of the clamping valve member enough to straighten the tight section 75 of the flexible pipe 49, enough for the clamping valve to open for the fluid to move. through it. Put another way, the flexible pipe chamber opens or closes in response to the amount of tension on the pipe. The clamping valve of the invention is also useful as a part of fluid transfer apparatuses that fit over rotating peristaltic pumps with housings of different configurations, such as the prior art pump illustrated in Figure 10. The clamping valve of the fluid transfer apparatus 42p mounted on the housing 41p of the pump, as seen in Figure 10, is under sufficient tension to stretch the rod portion 84p of the pressure valve element, so that the pressure valve open to fluid flow. The clamping valve of the invention is also useful in many other establishments where fluid is to be transferred through a flexible tubing, including in-line peristaltic pumps where there is a need for an automatic element to stop the flow of fluid in the tubing. If a flexible configuration of the flexible pipe is disturbed a little. In Figure 12, an alternative tightening valve element 80a is shown, having a substantially planar and substantially rectangular rod portion 84a, which connects the substantially planar and substantially rectangular end portions 82a, 83a. The end portions 82a, 83a each have a concave surface adapted to conform in a conformed manner against the outer cylindrical surface of the flexible pipe 49, and are bonded or adhered thereto, as seen in Figure 11, after bending the flexible pipe section 75, so that a connection with the length of the rod portion 84a can be made much shorter than the length of the flexible pipe section encompassed 75 in the resulting clamping valve. In Figure 14, another alternative tightening valve member 80b is seen having a shape like the capital letter "I", and is formed of a sheet-like, flexible, elastic, flat polymeric material. The clamping valve member 80b is attached to the flexible pipe 49 by wrapping the wider blade type end portions 82b, 83b substantially around the flexible pipe, and bonding or adhering thereto as seen in Figure 13, at the longitudinally spaced locations of the flexible pipe 49, which is the length of the rod portion 84b, wherein the flexible pipe section 75 between the end portions 82b, 83b is bent and tightened to close, as shown in FIG. Figure 13, when the flexible pipe 49 is not under a longitudinal tension. In Figure 16 there is still another alternative tightening valve element 80c, wherein a portion of rod 84c, having an arcuate cross-section of half-cylinder or semi-cylindrical shape, joins the arcuate end portions 82c, 83c which are grooved precisely on the concave surface which engages the external cylindrical surface of the flexible pipe 49, as shown in Figure 16a. As in the case of the other clamping valve embodiments illustrated herein, the flexible pipe 49 is bent during the assembly of the clamping valve shown in Figure 15, such that the covered section 75 of the pipe flexible will be much longer than the shank portion 84c of the tightening valve element. The thermal bonding or the adhesion of the end portions 82c, 83c of the tightening valve member with the flexible pipe 49 terminates the manufacturing of the tightening valve shown in Figure 15.

In Figure 18 there is still shown another alternative clamping valve element 80d, wherein a rod portion 84d, and the end portions 82d, 83d, are all part of a semi-cylindrical sleeve part of an elastically flexible polymer material shown in Figure 17 attached, for example, by link or adhesive, to flexible pipe 49, to form another embodiment of the clamping valve of the invention. Again, in the bonding or bonding of the rod portion 84d to the flexible pipe 49, the pipe section 75 is sharply bent, such that the end portions 82d, 83d of the clamping valve member, join in locations longitudinally spaced along the flexible pipe 49, so that the pipe section 75 is substantially longer than the stud portion 84d to provide the valve effect responsive to tension. In Figures 19 to 21, another embodiment of a tightening valve member 80e is partially illustrated, and also entirely assembled with a length of flexible tubing. The clamping valve member 80e comprises the shortened tubular segment end portions 82e, 83e joined by a rod-shaped rod portion or portion 84e. The end portion 82e is initially molded into an insert with the flexible tubing 49, such as its positioning collar 60 which is spaced apart from the end portion 82e by the intended stretch of covered tubing section 75. The section 75 of the flexible tubing 49 between the tubular segment end portion 82e and the positioning collar 60, is then sharply folded, and the tubular segment end portion 83e slides over the adjacent end of the flexible tubing 49, until the flexible tubing 49, until the end portion 83e is adjacent to the positioning collar 60, where the tubular segment end portion 83e is bonded or adhered in place, thereby forming the clamping valve illustrated in Figure 20. As shown in FIG. shown in Figure 21, when the pipe 49 is placed under a sufficient longitudinal tension, the shank portion 84e yields, and the covered flexible pipe section 75 straightens it. enough for the fluid to flow through it. Referring now to Figures 22 to 24, there is another embodiment of a tightening valve member 80f, which has closed circuit or eye-shaped end portions 82f, 83f joined by a narrower shank portion 84f. An end portion 82f of the clamping valve member is telescopically positioned around the flexible tubing 49, at a selected distance from one end thereof, and then the flexible tubing is sharply bent between the position of the end portion of the element of tightening valve 82f and the nearest end of the flexible pipe, and the other end portion 83f is telescopically placed around the flexible pipe, to a position defining the flexible pipe section 75, and the end portions are interlocked or stick in their place. For example, a polymeric silicone composition that is vulcanized at room temperature can serve as a suitable adhesive to be inserted along or just below the margins of the end portions of the tightening valve element. The finished clamping valve responds to the tension, closing when it is not under tension as seen in Figure 23, and being able to open under sufficient tension as illustrated in Figure 24. Referring now to Figure 25, it is still done Another form of tightening valve that responds to stress, by molding a sharply bent piece of a highly elastic spring material, such as metal spring wire 181, or a suitable spring polymeric material, into the wall 182 of a length of flexible pipe. The memory of the sharply bent spring material causes the flexible pipe to tighten to close when there is not enough longitudinal tension applied to the flexible pipe. As seen in section in Figure 26, wall 182 of the pipe becomes thicker along a longitudinal side to accommodate molding or extrusion of highly elastic spring material 181 therewith. Alternatively, a sharply bent piece of a highly elastic spring material, such as a spring wire 181, or a suitable polymeric material, may also be molded on the outside of the wall 183 of the flexible pipe, as indicated in FIG. the sectional view of Figure 26a. Using another mode of action, a clamping valve is made which responds to the tension, using a spring-loaded clamping valve element which is preformed with a memory which causes the ends of the valve element to be twisted sufficiently to close the chamber of a valve. Flexible pipe telescopically encompassed by the valve element. This clamping valve element is identified by the reference numeral 80g in Figure 27, wherein the clamping valve element, having tubular segment end portions 82g, 83g and a rod, in the form of a plurality of 84g longitudinal enervators that are twisted helically, connecting to the end portions, are shown assembled telescopically on a length of flexible tubing. During assembly, the tightening valve element 80g is placed under a longitudinal tension to straighten the longitudinal ribs 84g, while the flexible pipe section 49 is inserted through the tightening valve element, and is bonded or adhesively bonded , while maintaining the longitudinal tension on the tightening valve element 80g. By relaxing the longitudinal tension on the assembled clamping valve, the clamping valve element 80g twists the covered section of the flexible pipe, squeezing it to close it. Under tension, the resulting pressure valve is untwisted to unclamp the flexible pipe, allowing the passage of fluid through it. Accordingly, it is evident that many embodiments of the clamping valve element employed in the clamping valve which responds to the tension of the invention, in many different forms, can be made from the elastically flexible polymeric material, and can be configured to having two end portions connected by a portion of the rod. The end portions must be able to be attached to the flexible tubing from which the clamping valve is formed, and they must be joined with the end portions spaced a greater linear distance along the flexible tubing than the length of the rod portion. not stretched from the tightening valve element, at a relative distance in the scale of about 4: 1, varying only slightly as it will be immediately apparent, in accordance with the elastic performance resistance of the shank portion of the tightening valve element and the bend resistance module of the flexible pipe, so that the section of pipe covered is tightened or twisted sharply, enough, by the pull of the rod portion when the pressure valve is not under tension, so that the closure or occlusion of the fluid flow through the flexible tubing takes place. In all modes, the rod portion must be elastically deformed under an appropriate tension for the establishment where the valve is used, so that the clamping valve does not open under the longitudinal tension applied to the flexible tubing for operations or procedures. that they are being made, and yet close when the tension is released or absent. A clamping valve responsive to the tension of the type shown in Figures 10 has been assembled, by placing the clamping valve member on a length of pipe, using the assembly apparatus disclosed herein, which is useful for place a flexible shortened tubular segment, and at least a little elastic, telescopically on and near one end of a length of pipe having an external diameter substantially equal to or greater than the inner diameter of the tubular segment. A very important aspect of the assembly apparatus disclosed herein is the ability to eject the assembled combination of a flexible tubular segment and a length of tubing from the assembly apparatus, without displacing the flexible tubular segment longitudinally along the length. of pipe.

For the purposes of the specification and the claims, it is to be understood that the side or the front surface, also referred to herein as a first surface, of the assembly apparatus, is the side or surface where the section is inserted. of pipe to place a flexible tubular segment thereon, while the side or the rear surface is opposite the side or front surface. A forward movement is a movement to the side or front surface as defined herein, while a backward movement or extension is taken in the opposite direction. As seen in the example embodiment shown in Figures 28 to 30, and in the sectional view of Figure 32, together with the part separated view of Figure 33, the present assembly apparatus is formed from a portion of body, generally indicated by reference numeral 341, which, if desired, may have a base support portion 342, which may be secured to the base plate 343, for example, by screws 403, if desired, to have stability during use. It should be understood that the support structure can take any suitable shape and orientation, and its parts are joined together by any suitable element, such as welding or fastening. As seen in Figure 33, the example assembly apparatus consists primarily of the body portion and suitable base or support portions, in addition to a subassembly, indicated generally by reference numeral 330, a cover plate 347, a first retaining ring 352, a control ring 357, a second retaining ring 366, and a rear support member 374. In the assembled apparatus, the subassembly 330, which has extensibly extensible extensible finger portions or retractable, it is placed in a cylindrical hole 344 extending through the body portion 341 from the first front face to the second rear face, and the other components are joined in the sequence and in the indicated positions, using screws and bolts. 402, 405, 406, 407, 408 or other suitable fasteners. The combination of the sub-assembly 330 with the extensor finger elements 339, as seen in the separate view in parts of Figure 37, together with the cover plate 347 and the control ring 357, when mounted in the portion of body 341, comprises a mechanical element for assembling a tubular segment with a section of pipe. Moreover, an integral part of the subassembly arranged concentrically and reciprocatingly within the mechanical element for assembly constitutes an element for ejecting an assembly from a tubular segment with a length of pipe, as will be further described herein. The element for assembly, which includes the mechanical element for extending and retracting the extensor finger element 339, is described in detail below, and is comprised primarily of: (1) a substantially cylindrical rotary sleeve 149, which can be rotated in the cylindrical hole 344 of the body portion 341 of the apparatus; (2) a control ring 357 for rotating the rotary sleeve 149; (3) a disc-shaped member 354 having spiral guides extending radially, i.e., spirally, 360, formed therethrough, and which are mounted coaxially on a first end of the rotary sleeve 149 in an annular recess; and (4) at least three extensor finger elements, indicated generally by the numeral 339, which are supported by a combination of the disc-shaped member 354 and the cover plate 347, and radially extend or retract by coercion of the disc-shaped member and the cover plate with the extensor finger elements. The ejector elements comprise: (1) a reciprocable piston 362, illustrated in Figures 36 and 37 as part of the assembly apparatus shown in different stages of the assembly process; (2) an ejector block 368 or 368a, as illustrated in Figures 34 and 35; and (3) ejector arms 371, in addition to the rotary sleeve 149, in the cylindrical passage with which they reciprocate the piston 368. The subassembly identified by the reference character 330 in Figures 33, 37, 39 and 40, includes the substantially cylindrical rotating sleeve 149, with a cylindrical passage extending therethrough, and into which the reciprocable piston is coaxially positioned, indicated generally by numeral 362. The reciprocable piston has a recess at one end, wherein an expulsion blog is coaxially placed, such as the ejector blog 368 or 368a illustrated in Figures 34 and 35. The ejector block has a plurality, in this example three, of longitudinal slots 370 therein, and where they are mounted pivotally, using the bolts 371b, the ejector arms 371, substantially parallel to the longitudinal axis of the piston 362, keeping in mind that, when the assembling apparatus is completely assembled, the piston coaxial with the hole 344 through the body portion 341. In a recess of the first end 365 of the piston 362, an ejector block 368, such as the ejector block shown in Figure 34, is mounted, in any suitable manner. The ejector block shown in Figure 34 has a rearwardly extending tongue type portion 338, which fits into a complementary hole or passage 336 of the piston 362, and is secured by an adjusting screw 337. The total length of the Ejector block used in the assembly apparatus, determines the distance from the end of the section of pipe where the tubular segment will be placed during the assembly process. In the assembly of a clamping valve element with two tubular segments as the end portions, it is necessary to assemble each tubular end portion with a given length of pipe in a separate operation, where the assembly apparatus is used with a block ejector that has the appropriate length. Accordingly, a shorter ejector blog, such as that shown in Figure 34, would be used to place the first tubular segment, for example, 82, while a longer ejector block 368a would be used, as shown in Figure 35. , in the assembly of the second tubular segment, for example, 83, with the pipe section to obtain the appropriate positioning of the tubular segments, and also reach the appropriate separation longitudinally along the flexible pipe between the tubular segments. Ejector block 368a is provided with a forwardly projecting axial extension 338b, which has a cross section large enough to serve as a stop for the pipe section, but is small enough to facilitate the use of a coil spring 363 for causing the piston 362 to recover after the ejection step. In the assembly of the present apparatus, the subassembly 330 shown in Figure 33 is formed by the selection of an ejector block 368 (or alternatively, the ejector blog 368a of Figure 35) of suitable dimensions, such as the ejector blog illustrated in Figure 34, and the placement of a plurality of pivotal ejector arms 371 in the respective slots 370 formed in the sides of the ejector blog 368, wherein the ejector arms are pivotally retained by the pins 371b, which pass through the walls of the slots, and through the ejector arms near a first end 333 of each arm. The number of ejector arms 371 and complementary slots 370 employed, preferably is at least three, to match the number of extensor finger elements 339. The ejector arms 371 are oriented substantially parallel to the axis of the ejector piston 362. The portion of tongue type projecting backward 338 of the ejector block 368 is inserted into the axial hole 336, at the 365 end of the piston 362, and secured with an adjusting screw as shown in Figure 32. Referring now to Figures 32 and 37, an elongated center guide rod 369 is inserted, and secured from any suitably, in a longitudinal axial hole 334 in the free end of the ejector block 368, or in a longitudinal axial bore 334a in the axial extension 338b of the ejector block 368a, if the longer extension block is part of the subassembly. Turning now again to Figures 36 and 37, an elastic annular member 372, which may be a conventional "O" ring, is placed around the ejector arms 371, approximately half the length, for example, in the notches 335 of the arms, to retain them grouped together around the extensor finger portions 358 in the final assembly. Adjacent to the second end 332 of each of the ejector arms 371, there is an elongated longitudinally extending slot 373 formed therethrough. Through each of the slots 373, a respective leg portion 356 of an extender finger member 339 extends radially outwardly from the piston axis line 362. As seen in Figures 37, 38 and 40, extensor finger elements 39 are "L" -shaped, each with a leg portion 356 and a thin finger, i.e., the finger portion 358. To accommodate reciprocal movement of the ejector arms 371 along the line axially during an ejection step, without interfering with the normal function of the extensor finger elements 339, the leg portion 356a joining the finger portion 358 with the leg portion 356 in each element, preferably becomes sufficiently thin , so that the sides of the slot 373 are not fixed against the leg portion 356a. The means for assembling a tubular segment telescopically over a section of tubing is part of the sub-assembly 330, which includes the extensor finger elements 339. Mechanical elements for radially extending the extensor finger portions include the disc-shaped member 354 , as well as the rotating sleeve 149, on which the disc-shaped member 354 is mounted. The cover plate 347 with its radial channels 355, although not part of the subassembly 330, is also an essential part of the mechanical elements for extending and retracting the extensor finger portions in cooperation with the disc-shaped member 354 and its spiral guides 360. As best seen in Figure 38, each extensor finger element 339 is provided with a guide pin 359 extending laterally from about half the length of the leg portion 356, to extend into a spiral guide 360 of the disc-shaped member immediately to 354. With the finger elements 339 constrained by the radial channels 355 of the cover plate 347, in such a way that they can not rotate, the rotation of the disc-shaped member 354 provides a cam-like action, when the guide pins 359 are forced to slide along the respective spiral guides 360, moving the extensor finger members 339, and their finger portions 358, radially outward or inward, depending on the direction of rotation. In a further assembly of the sub-assembly 330 of Figure 33, as seen in Figure 39, a coil spring 363 slides over the group of ejector arms 371, followed by the disc-shaped member 354, in preparation for Attach it by means of the threaded fasteners 401 to the annular end face of the rotary sleeve 149, after sliding the piston 362 further into the passageway of the rotary sleeve 149, as seen in Figure 40. Also as seen in the Figure 40, the extensor finger elements 339 are positioned with the finger portions 358 concentrically grouped within the group of ejector arms 371 and around the center guide rod 369. The subassembly 330 shown in Figure 33, and to a large extent contained within the rotating sleeve 149, can now be inserted into the body portion 341 from the first front side 345 thereof, inside the hole 344, and extending partially beyond the second rear side 346 of the portion of body 341, and positioned as seen in Figure 32, such that the cover plate 347 can be attached by threaded fasteners 402, preferably using a locator pin 404 to align the grooves on the back side of the cover plate (described below) in the required operational orientation. The inner face, i.e. the back face, of the cover plate 347, as seen in Figure 41, is formed with radial channels 355, wherein the respective leg portions 356 of the extensor finger elements 339 are reciprocable when placed thereon, with the cover plate attached with the inner face turned face to face with the disc-shaped member 354. The radial channels 355 formed on the inner face of the cover plate 347, and with the portions of the finger elements of the finger extensors thereof are necessarily open towards the disc-shaped member 354, in such a way that the guide pins 359 can extend inwards, and slide along, the spiral guides 360. Referring again in a more particular way to Figures 32 and 33, it is seen that the body portion 341 encompasses the cylindrical hole 344, which is of a relatively large diameter compared to the body portion, and extends from the first surface or side 345 to the second surface or side 346 of the body portion. Although the assembly apparatus is shown in the drawing figures supported on a base, with the assembly apparatus oriented to receive an end portion of the pipe section disposed in a substantially horizontal manner during the assembly procedure, it is to be understood that the base can be modified, if desired, to support the apparatus with the hole inclined upward at any angle to receive the section of pipe, including by substantially vertically upward, without departing from the scope of the invention. In that case, the first front side of the apparatus, as described herein, would be the side or upper surface, and the second rear side would be the side or bottom surface of the assembly apparatus. The first surface 345 of the body portion 341 is substantially covered with the circular cover plate 347, with an opening 347a located at its center, while the second surface 346 of the body portion 341 is confronted with a first retaining ring 352, which has an internal diameter slightly smaller than the diameter of the cylindrical hole 344. The cover plate 347 and the first retaining ring 352 are fastened to the body portion 341, for example, by screws 402, 405, respectively, but it should be understood that any suitable element can be employed to retain these components in their relative operable positions. As best shown in Figures 32 and 33, inside the cylindrical hole 344, as indicated above, there is a substantially cylindrical revolving jacket or tube 149, having a first end 350 and a second smaller end 351. The rotating sleeve 149 it is retained in the cylindrical hole 344 by a flange or shoulder 353 of the rotating sleeve, which engages, or fits against, the radially inner portion of the first retaining ring 352, in the vicinity of the second surface 346 of the portion of body 341, and a radially outer flange portion, projecting forwardly, 350a, of the first end of the rotating sleeve, is retained by the cover plate 347. Although the first end portion 350 of the rotary sleeve 149 has a larger external diameter than the second end portion 351, and consequently that the flange or shoulder 353, the internal diameter of the cylindrical passage through the rotating sleeve is uniform, and the rotating sleeve will be referred to herein as substantially cylindrical. The second end 351 of the rotary sleeve 149 is disposed outside the cylindrical hole 344 and the first retaining ring 352, and is concentrically surrounded by a rotating control ring 357, preferably of a slightly larger diameter than the first retaining ring 352, and preferably having a knotted perimeter surface and / or a lever 361 extending therefrom, for easy handling. The control ring 357 is screwed or otherwise appropriately attached to the rotary sleeve 149. The first end 350 of the rotary sleeve 149 has a recessed annular end face, having a perimeter flange 350a, as indicated. In the annular recess radially inward from the flange 350a, the disc-shaped member 354 is fitted, which is screwed or otherwise fixedly attached to the end face, and has a central opening 354a of the same diameter as the opening 347a of the cover plate 347, but slightly smaller than the internal diameter of the passageway through the rotary sleeve 149. The rotating disk member 354 has a face which makes contact with the annular recessed end face of the rotating shirt 149, with which it joins, and the opposite face is face to face with, and can rotate against, the inner face of the front cover plate 347, which is attached to the body portion 341 and is not rotatable. As seen in Figures 48 and 50 in dotted delineation, and in perspective in Figure 41, the reverse side of cover plate 347 is provided with three equiangularly spaced channels 355, which open to the sides toward the shaped member. disc 354, and extend radially outwardly from the central opening 347a of the cover plate. Inserted in a reciprocable manner into each radially extending channel 355 from the central opening 347a is a leg portion 356 of an "L" shaped extensor finger element indicated generally by the reference numeral 339. The finger portions Extender 358 extends outwardly from the central opening 347a of the front cover plate 347, substantially parallel to the axis of the hole 344, to form a group, and it is this group that is manipulated radially apart to extend a tubular segment, such as a tubular segment end portion of a clamping valve element to permit its telescopic assembly on, ie, concentrically with, a length of pipe. The extensor finger portions 358, on which the tubular segments for extension, i.e. stretching to a larger cross-sectional opening, are placed during the telescopic assembly of a flexible tubular segment with a length of tubing in accordance with The invention is preferably very thin for easier removal of the combination of tubular segment and assembled tubing from the assembly apparatus. In this regard, it should be noted that the extensor finger portions 358 are sandwiched between a tubular segment end portion 382, 383 of the pinch valve element and the pipe 349 when the extensor finger portions are retracted prior to the expulsion step. . In Figures 37, 39 and 40, the disc-shaped member 354 is shown, having formed therein three parallel spiral guides extending radially, i.e., spirally, outwardly 360, which are open-sided. towards the cover plate 347. Each spiral guide extends spirally outward in the same direction of rotation from the central opening 354a of the disc-shaped member 354. Each leg portion 356 of an "L" -shaped extensor finger element. "respective 339, is provided with a guide pin 359 fixedly attached thereto., which extends laterally from the radial channel 355 of the cover plate 347, where it reciprocates the leg portion 356, in one of the spiral guides 360, along which it is slidable. Instead of the shown spiral guides cut entirely through the disc-shaped member 354, the guides 360 may be grooves cut in the same pattern, if they are each deep enough to easily receive and guide a bolt in a slidable manner. 359 during the rotation of the disc-shaped member 354, and the grooves open to the sides towards the cover plate 347. On the rotation of the disc-shaped member 354, using the knotted control ring 357 or the lever 361 for rotating the rotary sleeve 149, with which the disc-shaped member 354 is attached, a cam-type action is obtained to radially extend or retract the extensor finger portions 358 away from, or toward, the shaft common, when the leg portions 356 are moved radially by the respective guide pins 359 which slide in the spiral grooves 360. If desired, the lever 361 can be attached to the ani 357, as seen in Figures 29 and 33, used to rotate the control ring 357 through a sufficient arc, to obtain the desired extension and retraction of the extensor finger portions 358. Placed in the passage cylindrical of the rotary sleeve 149, and extending rearwardly therefrom, is the reciprocable piston 362, which reciprocates through a short range of movement within the cylindrical passage of the rotary sleeve 149, to perform the very important ejection procedure. The piston 362 is forced out of the passageway of the rotating sleeve 149 in an elastic manner by the coil spring 363, which rests on one end of the coil spring against the annular portion of the face of the disc-shaped member 354. which extends radially inward from the central opening of the rotary sleeve 149, and at the other end, against the first end 365 of the piston 362. The rear portion 364 of the second end of the piston 362, is of a slightly smaller diameter than the first portion 365, the rear end of the largest diameter portion constituting a shoulder on the piston, and a second retaining ring 366 attached to the control ring 357 having a central opening smaller than the largest diameter of the first portion 365 of the piston, to trap the shoulder and limit reciprocation of the piston 362 in the backward direction. Mounted in a recess of the face of the first end 365 of the piston 362, there is an ejector block 368 that is dimensioned longitudinally to serve as a stop to precisely limit the depth of insertion of a section of pipe on which a segment is to be placed tubular, such as a clamping valve element. In Figures 53 and 54, there is shown an assembly apparatus with an ejector block 368a, with a longer axial dimension, which provides a more superficial stop for the pipe inserted into the apparatus for the purpose of assembling the second end portion of the apparatus. tubular segment of a tightening valve element as a second step in the process of assembling a tightening valve. A central guide rod 369 extends axially from the ejector blog 368 or 368a through the passageway of the rotary sleeve 149, and substantially towards the outer ends of the extensor finger portions 358, where it is centered between them. It serves as a guide on which the section of flexible tubing in the assembly apparatus is inserted. Also, pivotally mounted, are the ejector arms 371 that extend forwardly along the interior of the passageway of the rotary sleeve 149, and almost parallel to the common axis, and outwardly through the aperture 354a of the disc-shaped member. 354, and of the opening 347a of the cover plate 347, wherein they rest against the surface radially outwardly of a portion of the extensor finger 358, collectively being forced in an elastic manner against the respective extenders fingers by an elastic springing annular member 372, such as a "0" ring. The ejector arms 371 must be selected to be of the proper length to make contact and abut against the edge of a flexible tubular segment, such as a tubular end portion of a tightening valve element, which has just been placed over a length of flexible tubing extending into the apparatus, simultaneously with contact and pressure between the ejector block and the inner end of the flexible tubing inside the apparatus, in order to avoid moving or displacing the tubular end portion longitudinally of the tubing Flexible during ejection. Due to the radially inward elastic tension of the tubular segment end portions of the clamping valve element on the flexible tubing, which has an outer diameter as large or larger than the inner diameter of the tubular segments, it is practically not feasible to remove the assembled clamping valve of the extensor finger portion without risking altering the positions of the tubular segment end portions of the clamping valve member, unless use is made of the ejection components of the apparatus. The second end or part 364 of the reciprocating ejection piston 362 is shown in Figures 29 and 32 supported by a support member 374 having a lower section 375 attached to the rear of the base portion 342 of the assembly apparatus, and an erect leg portion 376 extending upwardly to make contact with the rear portion 364 of the piston, which can be slid over the upper end with flange 377 of the leg portion 376. A section 378 of the underside of the rear part 364 of the piston 362 is flattened from adjacent the second end to the larger diameter front portion 365 of the piston 362, and it is this planar section that rests on the flanged upper end 377 of the leg portion 376 of the support element 374. The flat nature of the lower side section 378 serves to prevent the piston 362 from rotating during use, and the shoulders 378a, 378b formed at each end of the section 378 are trapped, respectively, on the upper end with flange 377 of the support element 374, and on the second retaining ring 366, to provide respective stop actions in the reciprocal movement of the piston 362. In the manufacture of a valve tightening that responds to the tension of the kind defined herein, it is essential for an appropriate valve action of the clamping valve, that the tubular segment end portions of the clamping valve member be positioned with some precision spaced apart to a rather short longitudinally, ie linearly, of the pipe section, the magnitude of the gap or separation being substantially greater than the length of the shank of the tightening valve element. This larger linearly spaced along the pipeline is essential in order to obtain a bend over the pipe which produces a clamping closure of the covered portion of the pipe when there is no tension on the portion of the pipe section that includes the tightening valve by itself, and the shank of the tightening valve member tends to elastically assume its normal length approximately, directing the mutually closer tubular segment end portions. The proper spacing during the telescopic assembly can be easily achieved in a convenient and efficient manner, using two nearly identical modalities of the assembly apparatus described herein, which differ primarily because they have ejector blogs of different lengths suitable for assembling the respective tubular segments. The ejector blocks serve as stops when advancing the length, or the degree, which may extend from the end of the pipe section into the assembly apparatus during the assembly process, thereby controlling the placement of the tubular segment end portions. The first embodiment of the assembly apparatus used will have a relatively short ejector block, such as that which is identified by the reference numeral 368 in Figures 32 and 36, and as shown in the perspective view of Figure 34, as such. so that the end of the pipe section will extend relatively deeper inside the assembly apparatus, and the first tubular segment end portion of the pressure valve member will be positioned far enough away from the inserted end of the flexible pipe to allow room for necessary spacing between the first and second tubular segment end portions. The telescopic assembly of the second tubular segment end portion can only be made closer to the inserted end of the pipe section, using the assembly apparatus, than the placement location of the first tubular segment end portion. The second embodiment of the assembly apparatus used to telescopically assemble the second tubular segment end portion should have a longer ejector block, such as the one identified by reference numeral 368a in Figures 53 and 54, and as shown in the perspective view of Figure 35, in such a manner that the flexible pipe will stop at a shallower depth for the assembly of the second tubular segment end portion of the tightening valve, closer to the end of the pipe section flexible than the first tubular segment end portion. The ejector block 368a can be seen in Figure 35, which has a smaller diameter extension 338b which serves as the actual stop inside the assembly apparatus for the end of the pipe section inserted during the assembly operations. The extension 338b has a smaller diameter than the ejector block 368a, in order to leave a circumferential annular space inside the rotary sleeve 149 for the coil spring 363. The base, the body portion and the parts such as the sleeve cylindrical, the reciprocable piston, the control ring and both retaining rings, the cover plate and the disc-shaped member, of the assembly apparatus can be made of light steel or of an easily machinable metal, such as an alloy of aluminum, if desired, but preferably made of tool steel or stainless steel. Preferably, the extensor fingers and the ejector arms are made of tool steel or stainless steel to provide greater strength and durability in the thinner members. Referring now to Figure 42, there is illustrated one embodiment of the assembly apparatus, together with a flexible clamping valve member 80, and a section 49 of flexible tubing of the same diameter illustrated in a part separated view. The clamping valve element 80, consisting of first and second shortened tubular segments 82 and 83, as the end portions, joined by a short stem portion 84 of approximately the same length as the end portions, is about to assemble telescopically on the section 49 of flexible pipe, near its end. It should be understood that the embodiment of the assembly apparatus shown in Figure 42 is eguided with an ejector block 68 of an appropriate length for positioning the first tubular segment 82 of the tightening valve member 80. In Figure 43, it is seen that the tightening valve element 80 is inclined to be assembled on the stretch 49 of flexible tubing, with the rod portion 84 of the tightening valve element bent to one side to stop the second tubular segment end portion 83 out of the way, so that the first tubular segment end portion 82 can be slid over the extensor finger portions 358, which are retracted close together as a group, as illustrated in Figure 43. In Figure 44, it is shown the first tubular segment end portion 82 slid over the group of extensor finger portions 358. The inner edge of the first tubular segment end portion must be in contact with the ends 337a of the ejector arms 331 to ensure accurate positioning during the assembly process. The sectional view of Figure 45 also shows the tubular segment end portion 82 slid over the extensor finger portions 358. In Figure 45, it is also seen that the apparatus is equipped with a very short ejector block 368 inside the first end of the ejector piston 362.

The rotation of the control ring 357, which concentrically surrounds, and is attached to, the rear end of the larger diameter portion of the rotating sleeve 149, causes rotation of the rotating sleeve, as well as of the disc-shaped member. 354 which is mounted on the front end 350 of the rotating sleeve. The rotation of the disc-shaped member 354 forces the guide pins 359 attached to the respective leg portions 356 of the extensor finger elements 339, to slide along the spiral guides 360 of the disc-shaped member, giving a cam-type action that moves the leg portions 356 in a radial direction into the radial channels of the cover plate 347, and the extensor finger portions 358 of the finger-expander elements 339, consequently move radially as well, which is the desired action. The direction and the degree of rotation of the disc-shaped member 354 determine the radial direction and the degree of movement of the extensor finger portions 358. In the next assembly step, the control ring 357 is then held, and made rotate manually, or the lever 361 can be used to rotate the control ring 357, in the proper direction and through a sufficient arc to extend the extensor finger portions 358, thereby stretching the first segment end portion tubular 82 to open, as shown in Figures 46, 47 and 48. Rotating the control ring 357 far enough, stretches the tubular segment 82 far enough to admit the end of the pipe section 49, which then slides through of the tubular segment with little or no friction and on the central guide rod 369, until the end of the pipe section hits the ejector block 368, which serves as a stop for the appropriate positioning of the tubular segment end portion 82 on the pipe section 49. The control ring 357 is then rotated by moving the lever 361 back to its initial position to relax the extension tension on the first end portion of the tube. tubular segment 82, terminating the assembly step for the first tubular segment end portion. To perform the ejection, the ejector piston 362 moves forward (towards the first surface 345 of the body portion 341) by any suitable element, against the coil spring 363 to move the ejector piston a small distance or separation from a position the second rear end 364 extends rearward, beyond the support element 374, until the ejector piston 362 reaches a previously established stop, as seen in Figure 49, where the rear edge 378a of the bottom surface is flattened 378 of the rear part 364 of the piston is trapped by the upper end with erect flange 377 of the erect leg section 376 of the support element 374. The piston 362 carries forward the ejector block 368 and the ejector arms 371, which make contact and eject in a simultaneous and respective manner, the end of the pipe section 49, and the nearest edge of the placed tubular segment 82 that has contact with the ends of the ejector arms 371a, as can be seen in Figures 49 and 50. In the previously established stop, the ejector arms 371 and the ejector block 368 will have coordinated ejection in a mechanical manner, with simultaneous pressure, the section 49 of flexible tubing and the first tubular end portion 82 of the clamping valve element. Although the piston 362 slides easily forward in a manual manner, towards the cover plate 347, if the coil spring 363 of a suitable spring tension is selected, the piston 362 can be equipped to reciprocate hydraulically or electromagnetically, if desired. you want Figure 51 shows the partially assembled tightening valve illustrated in Figure 49, to be further assembled using a second embodiment of the assembly apparatus, with a stop of a different depth, ie, more shallow, in the form of a longer ejector block 368a with an extension 338b. The short end section 85 of the flexible pipe section 349, between its front end and the first positioned tubular segment end portion 82 of the tightening valve element 80, has been bent out of the way so as not to prevent the sliding of the second one. tubular segment end portion 83 on the retracted extensor finger portions 358 of the assembly apparatus, until the tubular segment end portion makes contact with the ends of the ejector arms 7la, the rod portion 84 of the valve member being tighten 80 much shorter than the pipe section 85a disposed between the tubular segment end portions 82 and 83, which are assembled therewith (i.e., placed thereon). The second tubular segment end portion 83 of the clamping valve member is then slid over the extensor finger portions 358, and the control ring 357 is rotated to extend the extensor finger portions 358 and stretch the second portion of the finger. tubular segment end 83 of the tightening valve member 80, in a manner similar to that seen in Figure 46, and the short end section 85 of the flexible pipe section 49 is sharply bent, and the leading end slides in the extensor finger portions 358 and the second stretched tubular segment end portion 83 and on the center guide rod 369 and up against the ejector block 368a, as shown in Figures 52 and 53. As indicated, the longer ejector block 368a, which has an extension 338b, provides a stop at a more shallow depth of penetration, by the end of the pipe section 49 inside the apparatus. The ejector block 368a is selected to have an extension 338b of an appropriate length to provide the advance to a selected depth of penetration desired for the end of the pipe section 49, in order to achieve an appropriate placement of the second end portion of the tubular segment 83. To terminate the assembly of the second tubular segment end portion 83 of the clamping valve member, the control ring 357 is rotated rearwardly to retract extensor finger portions 358 closer together, to release the tension on the second tubular segment end portion 83, as shown in Figure 54. To perform the ejection in substantially the same manner as described for the first positioned tubular segment end portion 82, the ejection piston 362 it is pressed forward against the action of the coil spring 363, until the rear edge 378a of the bottom surface The flat portion 378 of the rear portion 364 of the ejection piston 362 is stopped by the upper end with flange 377 of the erect leg portion 376 of the support member 374, on which, the section 49 of flexible tubing and the second portion of tubular segment end 83 of the clamping valve element placed thereon, will be expelled as a unit, and manufacture of the flexible clamping valve is completed. It is preferred to finish the manufacture of the clamping valve by inserting a small amount of adhesive, such as a silicone adhesive that is vulcanized at room temperature, along the margins of the tubular segment end portions of the element. valve.

Claims

1. A tension-responsive clamping valve, comprising: an assembly of an elastically flexible clamping valve member, and a flexible pipe section having a chamber and a section to be reversibly closed as a valve; the clamping valve element being fixedly associated in a longitudinal manner with the section of the flexible pipe section, and being able to distort the section of flexible pipe to the point of tightening the chamber of the flexible pipe section to close it, when the pipe Flexible is not under tension, while allowing the chamber to open when the flexible piping is under sufficient tension to elongate the clamping valve member and to at least partially undo the distortion of the flexible piping section.

2. The clamping valve which responds to the tension of claim 1, wherein the elastically flexible clamping valve element is assembled to the external surface of the section of the flexible pipe section, the clamping valve member having the first and second end portions, and a portion of the rod connecting the end portions, the rod portion being longitudinally aligned with the section, and the end portions being joined to the section at separate points, the length of the section being between separate points sufficient greater than the length of the rod portion, so that the rod portion pulls the section inward from a sharp bend, squeezing the chamber of the section to close it, when the section is not under a longitudinal tension.

3. The tension responsive valve of claim 2, wherein the section length of the flexible pipe section between the spaced points is approximately four times greater than the length of the unstretched stem portion.

4. The tightening valve that responds to the tension of claim 2, wherein the end portions of the elastically flexible clamping valve member are tubular segments that are telescopically assembled with the section of the flexible pipe section, and the diameter The outer diameter of the flexible tubing is at least as large as the internal diameter of the tubular segments. The clamping valve of claim 4, wherein the section of the flexible pipe section is near one end of the flexible pipe section. The clamping valve responsive to the tension of claim 2, wherein the end portions of the clamping valve member are not tubular. 7. The clamping valve that responds to the tension of claim 6, wherein the end portions of the clamping valve member are ring-shaped. The tension-responsive clamping valve of claim 1, wherein the clamping valve member is a sharply bent spring wire. The clamping valve which responds to the tension of claim 8, wherein the section of the flexible pipe section to be closed in a reversible manner has a pipe wall, and the sharply bent spring wire is molded on the wall of the pipe. The clamping valve which responds to the tension of claim 8, wherein the section of the flexible pipe section to be closed in a reversible manner has a pipe wall, and the sharply bent spring wire is longitudinally molded on the outside of the pipe wall. The tension-responsive clamping valve of claim 1, wherein the clamping valve member is capable of twisting the section of the flexible pipe section to the point of tightening the chamber to close, when the section is not in place. under a longitudinal tension. 12. A tension-responsive clamping valve, comprising: an elastically flexible clamping valve element assembly, and a flexible pipe section having a chamber and a section to be reversibly closed as a valve; the clamping valve member comprising a flexible elastic polymeric material, and having a pair of tubular segment end portions joined by a rod portion, the tubular segment end portions being telescopically assembled with the flexible tubing, and the element being of tightening valve capable of distorting the flexible pipe section to the point of tightening the chamber of the flexible pipe section to close it, when the flexible pipe is not under tension, while allowing the chamber to open when the flexible pipe is under sufficient tension to elongate the clamping valve element and to at least partially undo the distortion of the flexible pipe section. 13. A tension-responsive clamping valve, comprising: an elastically flexible clamping valve element assembly, and a flexible pipe section having a chamber and a section that is to be reversibly closed as a valve; the clamping valve member comprising a flexible elastic polymeric material, and having a substantially planar rectangular rod portion connecting the substantially planar rectangular end portions, each of which has a concave surface adapted to conform conformably against a surface external cylindrical of the flexible pipe, and is connected to it, the tightening valve being able to distort the section of flexible pipe to the point of tightening the chamber of the flexible pipe section to close it, when the flexible pipe is not low tension, while allowing the chamber to be opened when the flexible tubing is under sufficient tension to elongate the clamping valve element and to at least partially undo the distortion of the flexible tubing section. 14. A tension-responsive clamping valve, comprising: an elastically flexible clamping valve element assembly, and a flexible pipe section having a chamber and a section that is to be reversibly closed as a valve; the clamping valve member comprising a flexible elastic polymeric material, and forming in the configuration of the capital letter "I" from a flat sheet, the end portions of the "I" being wrapped substantially around the flexible tubing and bonding with it, the tightening valve element being able to distort the flexible pipe section to the point of tightening the chamber of the flexible pipe section to close it when the flexible pipe is not under tension, while allowing the pipe to open. chamber when the flexible tubing is under sufficient tension to elongate the clamping valve element and at least partially undo the distortion of the flexible tubing section. 1

5. A tightening valve that responds to tension, which comprises: an assembly of an elastically flexible clamping valve member, and a flexible pipe section having a chamber and a section that is to be closed reversibly as a valve; the clamping valve member comprising a flexible elastic polymeric material, and having arcuate end portions that are joined by a rod portion, having an arcuate cross section, each end portion having a concave surface that engages with, and is bonded to, the outer surface of the flexible tubing, the clamping valve element being capable of distorting the flexible tubing section to the point of tightening the tubing section chamber to close it when the tubing does not it is under tension, while allowing the chamber to be opened when the flexible tubing is under sufficient tension to elongate the clamping valve element and to at least partially undo the distortion of the flexible tubing section. 1

6. A tightening valve that responds to tension, which comprises: an assembly of an elastically flexible clamping valve member, and a flexible pipe section having a chamber and a section that is to be closed reversibly as a valve; the clamping valve element being a semi-cylindrical sleeve-shaped part of a flexible elastic polymeric material, each end of the clamping valve element being joined to the flexible pipe, the clamping valve element being capable of distorting the flexible pipe section to the point of tightening the chamber of the flexible pipe section to close it when the flexible pipe is not under tension, while allowing the chamber to open when the flexible pipe is under sufficient tension to elongate the clamping valve element and undo at least partially the distortion of the flexible pipe section. 1

7. A tension-responsive clamping valve, comprising: an elastically flexible clamping valve element assembly, and a flexible pipe section having a chamber and a section that is to be closed reversibly as a valve; the clamping valve member comprising a flexible elastic polymeric material, the clamping valve member having a pair of tubular segment end portions joined by a rod portion, one of the end portions being molded as an insert around the flexible tubing. , and the other end portion being telescopically placed around the flexible tubing, and being separated from the first end portion by a positioning collar that is molded as an insert around the flexible tubing, the clamping valve element being capable of distorting the Flexible tubing section to the point of tightening the chamber of the flexible tubing section to close it when the flexible tubing is not under tension, while allowing the chamber to open when the tubing is under sufficient tension to elongate the tubing element. valve tighten and undo at least partially the distortion of the flexible pipe section. 1

8. A tension-responsive clamping valve, comprising: an elastically flexible clamping valve element assembly, and a flexible pipe section having a chamber and a section that is to be reversibly closed as a valve; the clamping valve member comprising a flexible elastic polymeric material, and having a pair of closed loop end portions joined by a rod portion, each end portion being telescopically placed around the flexible tubing, the valve element being tighten able to distort the flexible pipe section to the point of tightening the flexible tubing section chamber to close it when the flexible tubing is not under tension, while allowing the chamber to open when the flexible tubing is under sufficient tension to lengthen the tightening valve element and to undo at least partially the distortion of the flexible pipe section. 1

9. A tension-responsive clamping valve, comprising: an elastically flexible clamping valve element assembly, and a flexible pipe section having a chamber and a section that is to be closed reversibly as a valve; the clamping valve element being a sharply bent part of a highly elastic spring material molded into the wall of the flexible pipe, the clamping valve element being capable of distorting the section of flexible pipe to the point of tightening the chamber of the pipe. flexible tubing section to close when the flexible tubing is not under tension, while allowing the chamber to open when the flexible tubing is under sufficient tension to elongate the clamping valve element and at least partially undo the distortion of the section of flexible pipe. 20. A tightening valve that responds to tension, which comprises: an assembly of an elastically flexible clamping valve member, and a flexible pipe section having a chamber and a section that is to be closed reversibly as a valve; the clamping valve element being a sharply bent part of a highly elastic spring material bonded to the outside of the wall of the flexible pipe, the clamping valve element being capable of distorting the flexible pipe section to the point of tightening the chamber of the flexible tubing section to close it when the flexible tubing is not under tension, while allowing the chamber to open when the tubing is under sufficient tension to elongate the clamping valve member and to at least partially undo the distortion of the tubing. the flexible pipe section.