Patent Publication Number: US-2010116212-A1

Title: Tube arrangement

Description:
THE BACKGROUND OF THE INVENTION AND PRIOR ART 
     The present invention relates to a tube arrangement comprising a first tubular element, which has a peripheral surface and an inner channel adapted to transport milk, and a second tubular element, which has a peripheral surface and at least one inner channel adapted to transport air with a pulsation vacuum pressure. 
     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 a number of holding members. The holding member can be flexible annular elements of, for example, silicone. 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 comes in contact with, for example, the hooves of the cow or a protruding portion of a component during such a motion, there is a risk that the bundle gets caught in the cow or the component. There is also a risk that dirt is collected in cavities and gaps between adjacent tubes in such a bundle. Furthermore, if the long milk tube and the long pulse tubes get twisted, there is a risk that the cluster will not hang freely under the udder of a milking animal during the milking process. 
     DK 94 00044 U3 shows a flexible hose comprising three integrated parts in the form of a centre part and two side parts located on the opposite sides of the centre part. A milk channel is provided in the centre part and each side parts is provided with a pulse vacuum channel. However, if one of the including parts of the flexible hose will be damaged, the entire hose must be exchanged. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is to provide a tube arrangement comprising a first tubular element for transportation of milk and a second tubular element for transportation of air with a pulsating vacuum pressure, which tubular elements have a design such that it is easy to remove a damaged tubular element in the tube arrangement and replace it by a new one. 
     This object is achieved in that the peripheral surface of the first tubular element has an area with a substantially complementary shape to an area of the peripheral surface of the second tubular element and in that said complementary areas comprise fastening means adapted to releasably connect said complementary shaped areas of the first tubular element and the second tubular element to each other. Since the tubular elements have peripheral surfaces with complementary shaped areas, it is possible to arrange the tubular elements very close to each other in a connected state. Thereby, the tube arrangement obtains a small cross section area. By providing the complementary areas of the respective tubular elements with a releasable fastening means, it is possible to hold the tubular elements close together in a connected state at the same time as it is possible to remove a damaged tubular element in the tube arrangement and replace it by a new one. It is not necessary to exchange the entire tube arrangement if one of the tubular elements in the tube arrangement will be damaged. Such releasable fastening means may be an adhesive having releasable properties, a double-sided tape, a Velcro tape etc. Normally, the second tubular element has two inner channels adapted to transport air with a pulsating vacuum pressure. However, in certain applications, the second tubular element can have another number of inner channels such as, for example, one or four. 
     According to a preferred embodiment of the invention, the fastening means comprises a snap-fit connection between a part of the complementary area of the first tubular element and a part of the complementary area of the second tubular element. By the use of a snap-fit connection, it is possible to remove a damaged tubular element in a very quick and easy manner and replace it by a new one. The snap-fit connection may have a design such that mutual motions between the first tubular element and the second tubular element are allowed in a length direction of the tube arrangement. Such mutual motions between the tubular elements make it easier to bend the tube arrangement. Another advantage is that the tubular elements can be manufactured of relatively stiff elastic materials. By the use of a stiff elastic material in the tubular elements, the risk that the walls of the channels in the respective tubular elements are collapsed during loads, and thus the risk that the flow through the channels is stopped up, is considerably reduced. 
     According to a further preferred embodiment of the invention, the snap-fit connection comprises a protruding portion of one of the tubular elements and a recessed portioned portion of the other tubular element, wherein the protruding portion is adapted to be releasably locked into the recessed portion when the tubular elements are in a connected state. The protruding portion may comprise two resilient legs provided with locking surfaces adapted to come in engagement with locking surfaces of the recessed portion when the tubular elements are in a connected state. During a connecting motion of the legs into the recessed portion, the legs are pressed together by means of its resilient properties. When the legs have reached a locking position into the recessed portion, they will expand such that the locking surfaces come in engagement with the locking surfaces of the recessed portion. 
     According to a further preferred embodiment of the invention, the locking surfaces of the resilient legs and the locking surfaces of the recessed portion have an inclination such that it is possible to release the tubular elements from each other by applying a separating force of a predetermined value between the tubular elements in a releasing direction. The locking surfaces can be dimensioned such that said separating force is of a value such that the tubular elements do not risk coming loose from each other by mistake and such that it is possible to release the tubular elements from each other manually or by means of a tool. Advantageously, the protruding portion comprises guiding surfaces adapted to come in contact with surfaces of the recessed portion during an insertion motion of the protruding portion into the recessed portion. By means of said guiding surfaces, the protruding portion can be inserted into the recessed portion in a relatively quick and simple manner. The second tubular element may comprise an intermediate part and two side parts each comprising one inner channel of the second tubular element, wherein the intermediate part comprises said recessed portion. Such a design of the second tubular element makes it possible to provide a symmetric second tubular element with a centrally located recessed portion. 
     According to a further preferred embodiment of the invention, the first tubular element and/or the second tubular element comprise a passage having an extension from a peripheral surface to an inner space adapted to receive at least one conduit element. Thereby, it is possible to insert a separate conduit element of a suitable kind, such as an electric conduit element, through the passage and into the inner space of the tubular element. The risk that such a conduit element is caught in external objects during motions of the tube arrangement is eliminated. The inner space may have an extension between openings of end surfaces of the first tubular element or the second tubular element. Thereby, the conduit element may be threaded into the inner space from one of the end openings. The first tubular element and/or the second tubular element may comprise a passage having an extension from a complementary peripheral surface of the tubular element to said inner space. In this case, the conduit element must be inserted into the inner space before the first tubular element and the second tubular element are connected to each other. However, the passage to the inner space is completely covered by the tubular elements when they are connected to each other. Furthermore, it is possible to demount and exchange the first tubular element or the second tubular element of the tube arrangement without dismounting an electric conduit element from its end connections in connecting components. Thereby, the exchanging process may be performed in a very quick manner. 
     According to a further preferred embodiment of the invention, the passage and the inner space are located between the legs of the first tubular element. The conduit element obtains here a very safe position inside the tube arrangement when the first tubular element and the second tubular element are in a connected state. Furthermore, the existence of the passage and the inner space creates a space between the legs. This space makes it possible for the legs to be pressed together during the insertion motion of the legs into the recessed part. 
     According to a further preferred embodiment of the invention, a part of the peripheral surfaces of the first tubular element and a part of the peripheral surfaces of the second tubular element are adapted to form the outer peripheral surface of the tube arrangement when the first tubular element and the second tubular element are in a connected state. Consequently, the remaining parts of the peripheral surfaces of the first tubular element and the second tubular element, which not are complementary shaped and in contact with each other in a connected state, form the outer peripheral surface of the tube arrangement. Preferably, the outer area of the first tubular element forms at least partly a convex outer surface of the tube arrangement when the first tubular element and the second tubular element are in a connected state. It is very unlikely that such a shaped outer surface of a tubular element get caught in a surrounding object. 
     The outer area of the second tubular element may also form at least partly a convex outer surface of the tube arrangement when the first tubular element and the second tubular element are in a connected state. Preferably, the tubular elements have such shaped outer surfaces along at least a main part of its length. Advantageously, the outer area of the first tubular element and the outer area of the second tubular element have a design such that the tube arrangement in a limit zone between said areas obtains a smooth transition. Thereby, it is possible to give the whole tube arrangement a substantially convex and smooth outer surface. The risk that the tube arrangement gets caught in surrounding objects during motions of the tube arrangement is low. Furthermore, it is easy to keep a tube arrangement with such an outer surface free from dirt. 
     According to a further preferred embodiment of the invention, the first tubular element is manufactured of a material having elastic properties. Such a first flexible tubular element is bendable in desired directions. Preferably, the second tubular element is also manufactured of a material having elastic properties. Thereby, it is possible to bend the tube arrangement in a connected state in desired directions. The tubular elements can be manufactured of a thermoplastic elastomer TPE, polypropen PP, silicone or rubber. The first tubular element and the second tubular element may be manufactured of materials having different elastic properties. Thereby, it is possible to give certain parts of the tube arrangement more flexibility than other parts. It is also possible to manufacture the individual tubular elements in different kinds of materials having different properties in order to further give the tube arrangement desired properties. 
     The invention is also directed to a milking stall comprising such a tube arrangement. The tube arrangement can here replace the conventional long milk tube and the long pulse tubes which have an extension in parallel towards a milking member attachable to an animal to be milked. In a milking stall provided with a compact modular unit, the tube arrangement may have an extension from the compact modular unit to the milking member. Alternatively, tube arrangement can be connected to a teat cup. In this case, the second tubular element has one inner channel adapted to transport air with a pulsation vacuum pressure. However, it is also possible to use the tube arrangement in other positions in a milking stall where milk and a pulsation vacuum pressure are transported in parallel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention is now to be explained more closely by means of a preferred embodiment, which is disclosed as an example, and with reference to the attached drawings. 
         FIG. 1  shows a part of a milking stall comprising a tube arrangement according to the invention, 
         FIG. 2  shows a cross-section view of the tube arrangement with including tubular elements in a connected state and 
         FIG. 3  shows a cross-section view of the tube arrangement with including tubular elements in a separated state. 
     
    
    
     DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 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 teat cups  5 . Each teat cup  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 tube arrangement  6  has an extension 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 the transportation of the milk. The milk is transported from the respective teat cups  5 , via the short milk lines, the claw  4  and the tube arrangement  6  to the compact modular unit  1 . 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 adapted to supply a pulsating vacuum to the teat cups  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 pulsator is adapted to supply the pulsating vacuum, via the tube arrangement  6 , the claw  4  and the short pulse tubes, to a pulsating chamber of the respective teat cups  5 . In order to accomplish said pulsating vacuum, the pulsator is connected to a vacuum tube  11  and a fresh air tube  12 . 
     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, such as the milk pipeline system, 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, one or several electric cables  17  have to have an extension from the control unit in the compact modular unit  1  to the claw  4  of the milking member  3 . Such an electric cable  17  is possible to arrange inside the tubular arrangement  6 . 
       FIG. 2  shows a cross section view of the tube arrangement  6  in  FIG. 1 . The tube arrangement  6  comprises a first tubular element  18  having an inner channel  19  adapted to transport milk and a second tubular element  20  having two inner channels  21   a, b  adapted to transport air with a pulsation vacuum pressure. The milk channel  19 , which is dimensioned to transport milk from the claw  4  to the compact modular unit  1 , has a relatively large cross section area. The two vacuum pulse channels  21   a, b , which are dimensioned to transport pulsating vacuums from the claw  4  to the compact modular unit  1 , have smaller cross section areas than the milk channel  19 . The first tubular element  18  comprises a passage  23  and a relatively small inner space  22  adapted to receive at least one electric cable  17 . The first tubular element  18  and the second tubular element  20  are manufactured of materials having elastic properties. Such materials can be a thermoplastic elastomer TPE, polypropen PP, silicone and rubber. The first tubular element  18  and the second tubular element  20  can be manufactured of the same elastic material or of different elastic materials. Each of the first tubular element  18  and the second tubular element  20  can also be manufactured of different kinds of elastic materials. 
     The first tubular element  18  has a peripheral surface  24   a, b  and the second tubular element  20  has a peripheral surface  25   a, b . An area  24   a  of the peripheral surface of the first tubular element  18  has a substantially complementary shape to an area  25   a  of the peripheral surface of the second tubular element  20 . The first tubular element  18  comprises a protruding portion formed by two resilient legs  26 . The legs  26  can have an extension along the whole first tubular element or be arranged with suitable intervals in suitable positions along the extension of the first tubular element. Each leg  26  is provided with a locking surface  26   a  and a guiding surface  26   b . The passage  23  and the inner space  22  consist a space between the legs  26 , which makes it possible for the legs to be pressed together. The complementary area  25   a  of second tubular element  20  comprises a recessed portion  27  having a substantially complementary shape to the legs  26  of the first tubular element  18 . The recessed portion  27  is arranged in a part of the second tubular element  20  located between two side parts comprising the respective channels  21   a, b . The recessed portion  27  has a widened part in the vicinity of a bottom surface. The widened part comprises locking surfaces  27   a  adapted to come in engagement with the locking surfaces  26   a  of the legs  26  when the first tubular element  18  and the second tubular element  20  are in a connected state. In an unloaded state, the legs  26  take up a wider space than the width of certain parts of the recessed portion  27 . However, due to the resilient properties of the legs  26  and their guiding surfaces  26   b , it is easy to insert the resilient legs  26  into the recessed portion  27 . The legs  26  expand in a widened bottom part of the recessed portion  27  such that the locking surfaces  26   a ,  27   a  of the legs  26  and the recessed portion  27  come in engagement with each other and form a snap-fit connection which holds the first tubular element  18  and the second tubular element  20  releasably connected to each other. 
     When the first tubular element  18  and the second tubular element  20  are in the connected state, a remaining area  24   b  of the peripheral surface of the first tubular element  18  and a remaining area  25   b  of the peripheral surface of the second tubular element  20  form the outer surface of the tube arrangement  6 . 
     The outer area  24   b  of the first tubular element  18  forms a substantially smooth substantially convex outer surface of the tube arrangement  6 . The outer area  25   b  of the second tubular element  20  also forms a substantially convex outer surface of the tube arrangement  6 . The outer area  24   b  of the first tubular element  18  and the outer area  25   b  of the second tubular element  20  have a design such that the tube arrangement  6  in a limit zone  28  between said areas  24   b ,  25   b  obtains a smooth transition. As a consequence, the entire tube arrangement  6  obtains a smooth outer surface in a connected state. 
     Preferably, the first tubular element  18  and the second tubular element  20  have the same cross section area along their entire length. Thereby, it is possible for the first tubular element  18  and the second tubular element  20  to provide mutual motions in relation to each other in a longitudinal direction of the tube arrangement  6 . Such mutual motions between the first tubular element  18  and the second tubular element  20  can, for example, be provided when the tube arrangement is bent. 
       FIG. 3  shows the tubular elements  18 ,  20  and the electric cable  17  of the tube arrangement  6  in a separated state. The connection process of the separate parts  17 ,  18 ,  20  is performed in the following manner. Initially, the electric cable  17  is inserted into the passage  23  and is pressed into the space  22  of the first tubular element  18 . The passage  23  and the space  22  have an extension along the whole length of the first tubular element  18 . Thereafter, the first tubular element  18  and the second tubular element  20  are pressed together such that their complementary shaped surfaces  24   a ,  25   a  are moved against each other. The legs  26  of the first tubular element  18  are moved into the recessed portion  27  of the second tubular element  20  during this motion. The guiding surfaces  26   b  of the legs  26  have an inclination in relation to the walls of the recessed portion  27  which presses the legs  26  together and possibly widen the recessed portion  27 . Thereby, it is easy to insert the legs  26  of the first tubular element  18  into the recessed portion  27  of the second tubular element with a predetermined force. When the legs  26  reach the widened bottom of the recessed portion  27 , the legs  26  are expanded and the locking surfaces  26   a  of the legs and the locking surfaces  27   a  of the recessed portion  27  come in engagement with each other. A snap-fit connection is provided which holds the first tubular element  18  and the second tubular element  20  together in a releasable manner. In this state, the second tubular element  20  closes the passage  23  to the inner space  22 . As a consequence, the electric cable  17  obtains a very safe position inside the inner space  23  in the closed state of the tube arrangement. 
     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 tube arrangement  6  provides a motion in relation to the cow and several components in the milking stall. Thereby, the tube arrangement  6  risks coming in contact with the cow and said components. Since the tube arrangement  6  has a smooth and substantially convex outer surface along its whole length, the risk that the tube arrangement  6  gets caught in, for example, the hooves of the cow or a part of said components in the milking stall during the attachment process and the removing process of the milking member  3  is substantially negligible. Furthermore, the smooth surface of the tube arrangement  6  is free from pockets and cavities in which dirt can get caught. 
     If one of the tubular elements  18 ,  20  is damaged, it is very easy to release and exchange a damaged tubular element  18 ,  20  by a new one. If one of the tubular elements has to be exchanged, the respective tubular elements  18 ,  20  are gripped and a separating force is supplied in a releasing direction of the tubular elements  18 ,  20 . The locking surfaces  26   a  of the legs and the locking surfaces  27   a  of the recessed portion  27  have an inclination in relation to the releasing direction such the legs  26  are pressed together by the supplied force. When the force obtains a predetermined value, the legs are in a pressed together state such that they can be drawn out from the recessed portion. Thereafter, a new one can replace the damaged tubular element. 
     The invention is not restricted to the described embodiments disclosed in the figures, but may be varied freely within the scope of the claims. The second tubular element can, for example, have an arbitrary numbers of inner channels. The tube arrangement can be used in arbitrary applications where milk and a pulsation vacuum pressure are transported in parallel.