Patent Publication Number: US-2009223455-A1

Title: Tubular element

Description:
THE BACKGROUND OF THE INVENTION AND PRIOR ART 
     The present invention relates to a tubular element which comprises a body having an outer periphery surface with a shape in a cross section view such that adjacent parts of the periphery outer surface along a circumference of the tubular element forms an outer angle of at least 180° in relation to each other and a first channel located in said body adapted to transport a first fluid medium. 
     The outer surface of such a tubular element may have a continuous convex shape around the circumstance of the tubular element. Consequently, the tubular element may have a circular shape or oval shape in a cross section view. Alternatively, the outer surface comprises plane parts connected to each other around the circumference of the tubular element with a greater outer angle than 180° in relation to each other. Such a tubular element may be square shaped. However, the above-defined tubular element has an outer surface with a shape free from cavities. It is very unlikely that an outer surface of a tubular element having such a shape get caught in surrounding objects. Preferably, the tubular element has said shape along at least a main part of its length. 
     In a milking stall, the long milk tube and the long pulse tubes have an extension in parallel towards a claw of a milking member. In certain cases, one or several electric cables also have an extension in parallel with these tubes. It is known to hold such parallel tubes and electric cables in a connected state by means of special holding members. Inevitably, such a bundle of tubes and cables obtains an irregular outer surface with cavities and gaps between adjacent tubes and cables. During the attachment process and the removing process of the milking member, the bundle of tubes provides a motion in relation to a cow and plural components in the milking stall. If the bundle of tubes gets in contact with, for example, the hooves of the cow or a protruding part of a component during its motion, it is a risk that the bundle gets caught in the cow or the component. Furthermore, it is a risk that dirt is collected in cavities and gaps between adjacent tubes in such a bundle. 
     DE 196 36 273 shows a flexible milk hose provided with a milk channel, a pulse vacuum channel and an air channel. The flexible milk hose is connected to a milking member at an end portion. In certain cases, an additional conduit element, such as an electrical cable, has to be connected to the milking member in parallel with the milk hose. In these cases, a part of a cow or a component can get caught in the gap between the parallelly arranged milk hose and electrical cable during motions of the milking member. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is to provide a tubular element having a construction, which makes it possible to connect an additional conduit element to the tubular element in a manner such that the risk that the elements in a connected state are caught in an object is just as low as for a single tubular element. 
     This object is achieved in that the tubular element comprises an inner space, located entirely inside of the periphery outer surface of the body, wherein the inner space is adapted to receive at least one conduit element. Thereby, it is possible to arrange a separate conduit element of a suitable kind in the inner space of the tubular element. Since the inner space is located entirely inside the outer surface of the tubular element, the tubular element will have the same outer shape with or without a separate conduit element arranged in its inner space. Thus, the risk that the tubular element and a separate conduit element in a connected state are caught in an object during a motion is just as low as for the tubular element alone. It is possible to insert a separate conduit element into the inner space of an already fixedly mounted tubular element. It is also possible to insert a separate conduit element to the inner space of the tubular element during the mounting process of the tubular element. It is also a possibility to arrange the conduit element in the inner space of the tubular element as early as during a manufacturing process of the tubular element. In this case, the outer surface of a conduit element may be fixedly connected to the inner surfaces of the inner space of the tubular element. The tubular element may have an inner space having an extension between openings in the end surfaces of the tubular element. If the tubular element only has these openings to the inner space, the conduit element has to be threaded into the inner space from one of the end openings. 
     According to a preferred embodiment of the invention, the tubular element comprises an opening in the outer periphery surface through which it is possible to insert a conduit element into the inner space. By the use of such a periphery opening, it is easy to insert a conduit element into the inner space of an already mounted tubular element. Advantageously, said opening has an extension along the whole length of the tubular element. In such a case, it is possible to insert a conduit element into the inner space along the whole length of the tubular element or along a desired length of the tubular element. 
     According to a further preferred embodiment of the invention, the opening comprises a cover member adapted to cover the opening. A tubular element provided with a periphery opening requires a cover member which covers the opening. The cover member may comprise an outer surface which constitutes a part of the outer surface of the tubular element. Thereby, the cover member supplies a required outer surface over the periphery opening in the body. The cover member may be manufactured of a material having elastic properties. An elastic cover member may be displaced between a closed position and an open position in a simple manner. For example, when a conduit element is to be inserted through the periphery opening, the conduit element is pressed with a pressure against the outer surface of the cover member. Thereby, the conduit element moves the elastic cover member from its cover position to an open position. When the cover member is in the open position, it is possible to insert the conduit element into the inner space of the tubular element. As soon as the conduit element has been positioned in the inner space, the elastic cover member is returned to its cover position by means of its elastic properties. The cover member may constitute an integrated part of the body of the tubular element. Thereby, it is possible to manufacture the tubular element in one piece. Alternatively, a suitably shaped separate cover member may be used to cover the periphery opening after that a conduit element has been arranged in the inner space of the tubular element. 
     According to a further preferred embodiment of the invention, the periphery outer surface of the tubular element has a substantially circular shape in a cross section view. Such a tubular element has an outer surface with a continuously convex shaped outer surface around its circumference. It is very unlikely that a circular shaped outer surface of a tubular element get caught in a surrounding object. Preferably, the tubular element has a circular shape along at least a main part of its length. The parts of the tubular element which risk to get in contact with surrounding objects ought to have an outer periphery surface with a circular shape in cross section. 
     According to a further preferred embodiment of the invention, the tubular element comprises at least a first part manufactured of a first material having elastic properties. Such a tubular element has a flexibility such that it is possible to bend it in desired directions. Preferably, the tubular element comprises at least a second part manufactured of a second material having different elastic properties than the first material. Thereby, it is possible to give certain parts of the tubular element more flexibility than other parts. The body may comprise a periphery outer part manufactured of the first material and a periphery inner part manufactured of the second material, wherein the first material has softer elastic properties than the second material. Thereby, the walls of the inner channel are made of a stiffer elastic material than the periphery outer part. The use of a stiffer elastic material in the walls of the inner channel reduces the risk that the walls are collapsed during load such that the flow through the channel is stopped up. Thereby, it is possible to make the walls of the inner channel thinner and the tubular element lighter. Alternatively, the parts manufactured of different materials are positioned in the body such that the tubular element obtains different elastic properties in different bending directions. In many cases, it is not necessary that the tubular element has the same soft elastic properties in all bending direction. Thereby, it is possible to provide certain parts of the tubular element with a stiffer elastic material. The parts of stiffer material can be made thinner such that the tubular element achieves a lighter construction. 
     According to a further preferred embodiment of the invention, the first channel is adapted to transport milk. Consequently, the tubular element is provided with a channel dimensioned to receive and transport milk. If the milk is transported by means of a vacuum source, the walls of the milk channel have to be dimensioned to withstand the vacuum pressure in the milk channel. If a conduit element has an extension in parallel with the tubular element, it is possible to insert such a conduit element through the periphery opening to the inner space of the tubular element in a simple manner. The inner space may be adapted to receive at least one electrical cable. Consequently, the tubular element is provided with an inner space dimensioned to receive at least one electrical cable. If an electrical cable has an extension in parallel with such a tubular element, it is easy to insert the electrical cable into the inner space of the tubular element. 
     According to a further preferred embodiment of the invention, the tubular element comprises a second channel adapted to transport a second fluid medium. Such a tubular element provides the possibility to transport two different fluid mediums in one tubular element instead of in several separate tubes. Thereby, the number of tubular components will be reduced. The second channel may be adapted to transport air with a pulsation vacuum pressure. The long milk tube and the long pulse tubes in a milking stall have an extension in parallel. These tubes may be replaced by a tubular element having a milk channel and two vacuum pulse channels. The walls of the vacuum pulse channels have to be dimensioned to withstand the vacuum pressure in the pulse channel. 
     The invention is also directed to a milking stall comprising such a tubular element. The tubular element may here be connected to a milking member. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention is now to be explained more closely by means of preferred embodiments, which are disclosed as examples, and with reference to the attached drawings. 
         FIG. 1  shows a part of a milking stall comprising a tubular element according to the invention, 
         FIG. 2  shows a cross-section view of a tubular element according to a first embodiment of the invention, 
         FIG. 3  shows a cross-section view of a tubular element according to a second embodiment of the invention and, 
         FIG. 4  shows a cross-section view of a tubular element according to a third embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION 
       FIG. 1  shows a part of a milking stall for milking of cows. The milking stall comprises a compact modular unit  1  mounted on a wall surface  2   a  of a pit  2 . The milking stall comprises a milking member in the form of a cluster  3 , which comprises a claw  4  and four teatcups  5 . Each teatcup  5  is connected to the claw  4  by means of a short milk tube and a short pulse tube. However, the four short pulse tubes have not been indicated in the figure. A tubular element  6  is mounted between the claw  4  of the milking member  3  and the compact modular unit  1 . The milking stall comprises a milk pipeline system having the function to transport milk from a cow in the milking stall to a milk-collecting container. The milk pipeline system is in a conventional manner connectable to a vacuum source for this transportation of the milk. The milk is transported from the claw  4  to the compact modular unit  1  through a milk channel  7  arranged inside the tubular element  6 . The milk channel  7  is shown in  FIG. 2 . A milk tube  8  conducts the milk from the compact modular unit  1  towards said milk-collecting container. A not visible milk meter is mounted in an inner space of the compact modular unit  1  for measuring of the milk flow through the compact modular unit  1 . 
     Further, the milking stall comprises a vacuum pipeline system, which is arranged to supply a pulsating vacuum to the teatcups  5  during a milking process of an animal. The vacuum pipeline system comprises a not visible pulsator mounted in the inner space of the compact modular unit  1 . The vacuum pipeline system comprises two vacuum pulse channels  9   a, b  in the tubular element  6 , which are shown in  FIG. 2 . The pulse channels  9   a, b  are arranged to supply a pulsating vacuum from the pulsator, via the claw  4  and the short pulse tubes, to a pulsating chamber of the respective teatcups  5 . In order to accomplish pulsating vacuums in the channels  9   a, b , the pulsator is connected to a vacuum source via a vacuum tube  11  and a fresh air source via a fresh air tube  12 . The pulsator connects the channels  9   a, b  in the tubular element  6  alternately to the vacuum tube  11  and the fresh air tube  12 . Thereby, a pulsating vacuum arises in the respective vacuum pulse channels  9   a, b  in the tubular element  6 , which is supplied to the respective pairs of teatcups  5 . 
     The milking stall comprises a not visible electric control unit mounted in the inner space of the compact modular unit  1 . The electric control unit is arranged to control and supervise the milking processes in the milking stall. Consequently, the electric control unit has the function to control several systems used in the milking stall. The electric control unit controls the milking vacuum in the milk pipeline system, the pulsation vacuum and pulsation rate/ratio/stop etc. in the vacuum pipeline system and a schematically indicated remover  13 . The remover  13  has the function to remove the cluster  5  from the cow when a milking process is finished in the milking stall. The control unit controls the remover  13  by means of an electric signal line  14 . The electric control unit may also have the function to communicate with a main control system for a plurality of milking stalls. Therefore, an electric cable in the form of an electric signal line  15  is connected to the compact modular unit  1 . Furthermore, the electric control unit is connected to an electric power source via an electric cable  16 . In certain cases, at least one electrical cable  17  has to have an extension from the control unit in the compact modular unit  1  to the claw  4  of the milking member  3 . The tubular element  6  is provided with an elongated inner space  18 , in which it is possible to releasably mount such an electrical cable  17 . 
       FIG. 2  shows a cross section view of the tubular element  6  in  FIG. 1 . The tubular element  6  comprises a body  19  manufactured of an elastic material. The body  19  has an outer periphery surface  20  having a substantially circular shape around its circumference. The tubular element  6  has a circular shape along its whole length. The milk channel  7  is dimensioned to transport milk from the claw  4  to the compact modular unit  1 . The milk channel  7  has a relatively large cross section area. The two vacuum pulse channels  9   a, b  are dimensioned to transport pulsating vacuums from the claw  4  to the compact modular unit  1 . The vacuum pulse channels  9   a, b  have smaller cross section areas than the milk channel  7 . 
     The inner space  18  of the tubular element  6  is located entirely inside of the outer periphery surface  20  of the tubular element  6 . The inner space  18  is adapted to receive at least one separate conduit element. In this case, an electrical cable  17  has been arranged in the inner space  18  of the tubular element  6 . The tubular element  6  comprises an elongated opening  21  in its outer periphery surface  20  to the inner space  18 . The opening  21  has a shape and size such that it is possible to insert at least one separate conduit element into the inner space  18 . The inner space  18  and the opening  21  have an extension along the whole length of the tubular element  6 . The tubular element  6  comprises a cover member, in the form of two cover lips  22   a, b  adapted to cover the opening  21 . The cover lips  22   a, b  have an extension from opposite sides of the opening  19  to their free edge surfaces which are met in a substantially centre position of the opening  21 . The cover lips  22   a, b  are adapted to substantially completely cover the opening  21  to the inner space  18  when they are in a closed position. The cover lips  22   a, b  have an outer surface  20 ′ constituting a part of the outer surface  20  of the body  19 . The cover lips  22   a, b  are manufactured of the same material as the rest of the body  19 . The body  19  of the tubular element  6  is manufactured in one piece of one elastic material. 
     When a separate electrical cable  17  is to be inserted through the periphery opening  21  to the inner space  18 , the electrical cable element  17  is pressed with a certain pressure against the outer surface  20 ′ of the cover lips  22   a, b . The pressure from the cable element  17  moves at least a part of the flexible cover lips  22   a, b  into the inner space  18 . Thereby, the cover lips  22   a, b  are moved from the closed position to an open position. When the cover lips  22   a, b  are in the open position, it is possible to insert the electrical cable element  17  into the inner space  18 . As soon as the electrical cable element  17  has been positioned in the inner space  18 , the flexible cover lips  22   a, b  are returned to the closed position by means of their elastic properties. 
     During the attachment process of the milking member  3  to a cow and the removing process of the milking member  3  from a cow, the tubular element  6  provides a motion in relation to the cow and several components in the milking stall. Thereby, the tubular element risks getting in contact with parts of the cow and said components. The tubular element  6  has the same circular shaped outer surface  20  along its whole length with or without an electrical cable  17  arranged in the inner space  18 . Thereby, the risk that the outer surface  20  of the tubular element  6  gets caught in, for example, the hooves of a cow or a part of a component in the milking stall during the attachment process and the removing process of the milking member  3  is substantially negligible. Furthermore, the use of the tubular element  6  reduces the number of tubular components in the milking stall since it replaces the conventional long milk tube and the two conventional long pulse tubes. 
       FIG. 3  shows an alternative embodiment of the tubular element  6 . In this case, the body  19  comprises a periphery outer part  19   a  manufactured of a first elastic material. The periphery outer part  19   a  comprises the periphery outer surface  20  of the body  19 . The body  19  comprises a periphery inner part  19   b  manufactured of a second elastic material. The periphery inner part  19   b  forms the walls of the milk channel  7  and the pulse channels  9   a, b . The first material has softer elastic properties than the second material. Consequently, the milk in the milk channel  7  is transported by means of a vacuum source and the pulse channels  9   a, b  are arranged to transport a pulsating vacuum. Thereby, the walls of the channels  7 ,  9   a, b  have to be dimensioned such that they withstand the vacuum pressure inside the channels  7 ,  9   a, b . By the use of a stiffer elastic material in the periphery inner part  19   b  of the tubular element  6 , the walls of the channels  7 ,  9   a, b  can be made thinner. As a result, the tubular element  6  obtains a lower weight. In this case, a first cover lip  22   a ′ is used having an extension over the whole width of the opening  19 . A shorter second cover lip  22   b ′ is arranged in an internal position of the free end portion of the first cover lip  22   a ′. In this case, the first cover lip  22   a ′ provides the whole periphery outer surface  20 ′ of the cover member. 
       FIG. 4  shows a further alternative embodiment of the tubular element  6 . In this case, the tubular element  6  comprises a body  19  having a soft elastic material in three parts  19   a ′ and a stiffer elastic material in two parts  19   b ′. The parts  19   a ′,  19   b ′ are positioned in the body  19  such that the tubular element  6  obtains different elastic properties in different bending directions. In certain cases, it is sufficient if the tubular element  6  is bendable in certain directions. One of the stiffer elastic parts  19   b ′ includes a wall arranged between the milk channel  7  and the pulse channels  9   a, b . This stiffer elastic part  19   b ′ reduces the possibility to bend the tubular element in a horizontal plane in  FIG. 4  but not especially in a vertical plane. At the same time, such a stiffer elastic part  19   b ′ supplies a higher strength to the walls of the channels  7 ,  9   a, b  than a softer elastic material. Thereby, it is possible to give at least this part  19   b ′ a thinner wall thickness than a corresponding wall made of a softer elastic material. In such a manner, the tubular element  6  can obtain a reduced weight. 
     The invention is not restricted to the described embodiments disclosed in the figures, but may be varied freely within the scope of the claims. It is, for example, possible to provide the tubular element with several separate such inner spaces each adapted to receive at least one conduit element.