Abstract:
In the gradient controller according to the invention, the value arrangement ( 32 ) has a valve pin ( 33 ) closing as a result of its own weight. Springs are therefore unnecessary. The valve pin ( 34 ) can be guided directionally so as to be capable of being moved up and down, thus ensuring that the gradient controller has a high degree of reliability. 
     Also provided is an insert part ( 37 ) which can be taken out of the gradient controller and in which the valve pin ( 34 ) is capable of being moved up and down and is secured against falling out. The insert part ( 37 ) and the valve pin ( 34 ) thereby form a unit which can be taken as a whole out of the gradient controller, specifically both for maintenance purposes and for exchanging the valve pin ( 34 ) for one with a different weight, with the result that it is possible in a simple way to change the pressure compensation ratio of the gradient controller.

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The invention relates to a device for compensating the pressure of a liquid in a liquid conduit of an animal drinking trough with a housing which is capable of being inserted into the liquid conduit and in which chambers for inflowing liquid and for outflowing liquid are located, at least one valve arrangement being arranged between the chambers separated by a partition. The invention relates, furthermore, to a method for changing the pressure compensation ratio, in particular of a device for compensating the pressure in a liquid conduit, according to the pressure of the inflowing liquid being changed to a lower pressure for outflowing liquid by means of a valve arrangement having a valve body. 
     2. Prior Art 
     Devices of the type referred to here are designated in the specialized jargon as gradient controllers. They are preferably used along inclined liquid conduits for feeding drinking nipples for animals, for example poultry. In the case of inclined liquid conduits, the pressure rises along these. The gradient controllers serve for equalizing the pressure along the inclined liquid conduit. 
     There are known gradient controllers having a valve arrangement which possesses a spring-loaded valve body. The springs necessary for this purpose often present problems in practice. For example, over a period of time, the springs may fail due to a fracture. The known gradient controllers therefore operate only unreliably. 
     BRIEF SUMMARY OF THE INVENTION 
     Proceeding from this, the object on which the invention is based is to provide a device (gradient controller) and a method of the type mentioned in the introduction, by which the pressure along inclined liquid conduits can be adapted according to the conditions in a simple and reliable way. 
     A device for achieving this object has the features of claim  1 . Since the valve arrangement possesses a preferably cylindrical valve pin which closes as a result of its own weight, the spring necessary in the known gradient controllers or gradient pressure controllers may be dispensed with. Moreover, the valve pin ensures that the valve arrangement opens and closes reliably, because said pin, by virtue of its preferably cylindrical shape, can be guided reliably so as to be capable of being moved up and down. 
     There is provision, furthermore, for assigning the valve arrangement to a chamber for outflowing liquid. The valve pin can thereby by arranged vertically above the chamber of the inflowing liquid. As a result of this, the valve pin capable of being moved up and down can, by its own weight, close the valve arrangement. 
     According to a preferred embodiment of the invention, the valve pin is provided, preferably on its underside, with a conical, in particular frustoconical, sealing surface. This frustoconical sealing surface matches a likewise conically, in particular frustoconically formed valve seat. A reliable seal is therefore ensured when the sealing surface of the valve pin rests on the valve seat. A gravity-induced reliable closing of the valve arrangement is ensured as a result, specifically even in the case of small valve pins which have only a low own weight. 
     According to a preferred embodiment of the invention, the guide for the valve pin is longer than the length of the latter. As a result, for scavenging the liquid conduit, the valve pin can be moved sufficiently far away from the valve seat. The gradient controller according to the invention consequently allows unimpeded scavenging of the drinking appliance. 
     There is provision, furthermore, for providing the guide for the valve pin in sleeve-like insert part which is arranged in a matching sleeve of the housing. Thus, by means of the insert part, the valve pin of the valve arrangement can be taken out of the gradient controller sleeve arranged on the housing, for example in order to clean the valve arrangement. So that the insert part, together with the valve pin, can be mounted and demounted, the valve pin is secured in the insert part against falling out. Preferably, for this purpose, the insert part has spring tongues which, by virtue of elastic deformation, make it possible to separate the valve pin from the insert part when the latter is to be exchanged. 
     A method for achieving the object mentioned in the introduction has the measures of claim  20 . Accordingly, the valve arrangement is provided with valve bodies of different own weight, in order to change the pressure compensation ratio of the gradient controller. In the case of a comparatively heavy valve body, the gradient controller brings about a greater pressure difference between the inflowing liquid and the outflowing liquid. Conversely, a lighter valve body leads to a smaller pressure difference in the chambers connected by means of the valve arrangement. 
     In the preferred method, the valve body is exchanged together with the insert part. The insert part arranged in the housing of the gradient controller so as to be capable of being pulled out can easily be mounted and demounted. 
     Alternatively, it is also possible to pull the insert part, together with the valve body, out of the sleeve of the housing and, with the insert part demounted, to exchange the valve body by the latter being separated from the insert part and replaced by a new valve body, in particular a valve pin. The same insert part may always be used when, according to a preferred embodiment of the invention, the different valve bodies or valve pins do not differ in diameter, but only in length. 
    
    
     BRIEF SUMMARY OF THE FIGURES 
     A preferred exemplary embodiment of the invention and the method according to the invention are explained in more detail below with reference to the drawing in which: 
     FIG. 1 shows a perspective illustration of the device, 
     FIG. 2 shows a top view of the device of FIG. 1, 
     FIG. 3 shows a side view, looking towards a water inflow, 
     FIG. 4 shows a section IV—IV through the device, and 
     FIG. 5 shows a section V—V through the device. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The device show here is a gradient controller or gradient pressure controller of a drinking appliance for animals, in particular poultry. The drinking appliance serves for supplying the animals with a liquid, in particular water, which, if appropriate, may contain additives, such as, for example, drugs. 
     The drinking appliance, otherwise not shown in the figures, is arranged, suspended, in a stable for accommodating the animals. The drinking appliance has an elongate water supply conduit running through the stable and having a, for example, square cross section with rounded corners. Arranged at the water inlet of the water supply conduit is a pressure reducer which reduces the water pressure of a water feed conduit to the operating pressure of the drinking appliance. Drinking valves are arranged at regular intervals along the water supply conduit. By appropriately actuating the drinking valves, the animals can obtain by themselves the amount of water which they require. 
     The water supply conduit often runs at a slight inclination to the horizontal. This occurs, in particular, when, for reasons of geography, a stable is erected on sloping ground or the water supply conduit has an artificial gradient to make cleaning simpler. In such water supply conduits running at a downward inclination from the water feed, the pressure along these rises continuously. The device according to the invention serves for equalizing the water pressure in such water supply conduits running at an inclination. As a rule, a plurality of such devices are arranged at uniform intervals along the water supply conduit. Such a drinking appliance is known, for example, from U.S. Pat. No. 5,870,970. Reference is made to this with regard to the basic make-up of the drinking appliance. Here, too, a plurality of gradient controllers, so-called “pressure regulators”, are arranged along the inclined water supply conduit. The device according to the invention is a further development or modification of the “pressure regulators” known from U.S. Pat. No. 5,870,970. 
     In the exemplary embodiment shown here, the device has a box-shaped housing  10  with an essentially rectangular base (FIG.  2 ). The housing  10  is formed from plastic. Opposite sides of the housing  10  have in each case two outwardly projecting protuberances  11 . 
     The housing  10  has a multi-part design. It is composed of a housing middle part  12  of a lower plane bottom plate  13  and of an upper likewise plane cover plate  14 . The housing middle part  12  is surrounded by a continuous vertical side wall which is composed of two parallel longitudinal side walls  15  and of two parallel transverse side walls  16 . One transverse side wall  16  is assigned a water inflow connection piece  17 , whilst the opposite transverse side wall  16  has a water outflow connection piece  18 . The water inflow connection piece  17  and the water outflow connection piece  18  lie on a common axis, to be precise the longitudinal mid-axis  19  of the housing  10 . The water inflow connection piece  17  and the water outflow connection plate  18  each have a square inner cross section of the same size or area, which matches the outer cross section of the water supply conduit. A seal  20  with a continuous elastically deformable sealing lip  21  is arranged inside the water inflow connection piece  17  and the water outflow connection piece  18  at a distance from the outer end in each case (FIG.  4 ). 
     The device can be inserted into the water supply conduit. The water supply conduit is separated where the device is to be arranged under given pressure conditions. At the separating point, a short portion of the water supply conduit is removed, so as to allow for, between the mutually confronting ends of the water supply conduit, a clearance which allows the device to be arranged between these ends of the separated water supply conduit. The device is connected to the water supply conduit by a short end region being pushed in each case into the water inflow connection piece  17  and the water outflow connection piece  18  at the separating point of the water supply conduit. The depth to which the respective portion of the water supply conduit is pushed into the water inflow connection piece  17  and the water outflow connection piece  18  is limited by a continuous collar  22  at that end of the water inflow connection piece  17  and of the water outflow connection piece  18  which faces the inside of the housing  10 . This collar  22  thereby slightly contracts the inner cross section of the water inflow connection piece  17  and of the water outflow connection piece  18 , specifically approximately to the inner free cross section of the water supply conduit. The end regions of the water supply conduit which are pushed into the water inflow connection piece  17  and the water outflow connection piece  18  are sealed off relative to the housing  10  by means of the seals  20 . 
     Upper and lower open end faces of the housing middle part  12  are covered by the bottom plate  13  and the cover plate  14 . These come to rest respectively under and on the end faces of the longitudinal side walls  15  and of the transverse side walls  16  of the housing middle part  12 . By means of a continuous seal  23  assigned in each case to the bottom plate  13  and to the cover plate  14 , the bottom plate  13  and the cover plate  14  are sealed off, water-tight, relative to the housing middle part  12 . The bottom plate  13  and the cover plate  14  are connected to the housing middle part  12  by means of screws  24  which are screwed from outside through the bottom plate  13  and the cover plate  14  into the protuberances  11  of the housing middle part  12 . 
     Located inside the housing  10  is a partition  27 . The latter subdivides the interior of the housing  10  into two chambers  25  and  26 . The water inflow connection piece  17  issues into the lower chamber  25 . The inflowing water thereby flows into the lower chamber  25 . The upper chamber  26  is connected to the water outflow connection piece  18 , so that water can flow out through the upper chamber  26  and through the water outflow connection piece  18 . The partition  27  is angled twice along its run between the water inflow connection piece  17  and the water outflow connection piece  18 . For this purpose, the partition  27  has a horizontal edge portion  28  lying above the water inflow connection piece  17  and a likewise horizontal edge portion  29  lying below the water outflow connection piece  18 . The edge portions  28  and  29  lying in different horizontal planes are connected by means of an obliquely directed middle portion  30  of the partition  27 . The middle portion  30  is somewhat offset laterally, that is to say is arranged eccentrically in the housing  10 . As a result, the edge portion  29  lying below the water outflow connection piece  18  has a greater length than the edge portion  28  arranged at a higher level on the other side of the middle portion  30 . 
     An orifice  31  is located in the partition  27 , specifically in the wider edge portion  29 . This orifice  31  is assigned a valve arrangement  32  (FIG.  5 ). The orifice  31  can be opened or closed, as required, by means of the valve arrangement  32 . Correspondingly, an inflow of water out of the chamber  25  connected to the water inflow connection piece  17  to a chamber  26  connected to the water outflow connection piece  18  is interrupted or released. If required, a plurality of orifices  31  and valve arrangements  32  may also be provided. 
     The valve arrangement  32  has a valve seat  33 , assigned to the orifice  31  in the partition  27 , and a valve pin  34  capable of being moved up and down and having a sealing surface  35  matching the valve seat  33 . The elongate valve pin  34  is capable of being moved up and down on a vertical longitudinal mid-axis  36 . The valve arrangement  32 , specifically, in particular, the valve pin  34 , is assigned to the top side of the partition  27 , said top side facing the chamber  26  for outflowing water. 
     The valve pin  34  is guided so as to be capable of being moved up and down in a cylindrical insert part  37 . The insert part  37  thereby forms for the valve pin  34  a guide which, in the exemplary embodiment shown, is cylindrical. The insert part  37 , in turn, is arranged releasably in a sleeve  38 . The sleeve  39  is connected to the cover plate  14 , specifically, in the exemplary embodiment shown, in one piece. The sleeve  38  projects with a smaller part into the chamber  26  inside the housing  10 , whilst a larger part of the sleeve  38  projects upwards relative to the cover plate  14 . The insert part  37  has a continuous sealing ring  39 , by means of which it is sealed off relative to the sleeve  38 . That part of the sleeve  38  which projects upwards relative to the cover plate  14  is assigned a securing shackle  40 . The latter is mounted pivotably about a horizontal axis at two opposite bearing points  41  on the outside of the sleeve  38 . In a closing position, the securing shackle  40  rests against the top side of the insert part  37  and thus holds the latter in the inserted position in the sleeve  38 . A flat grip  42  projecting relative to the top side of the insert part  37  is partially surrounded by a U-shaped protuberance  43  of the securing shackle  40 , with the result that the insert part  37  is held essentially non-rotatably in the sleeve  38 . The grip  42  has, in the middle, a cylindrical widening  44  which matches corresponding shaped-out portions  45  in the protuberance  43  of the securing shackle  40  and thereby forms a latching connection of the securing shackle  40  in the position in which the latter secures the insert part  37  in the sleeve  38  (FIG.  1 ). 
     The valve pin  34  is of rotationally symmetrical, to be precise cylindrical design. It is composed of two cylinder portions  46  of different diameters. A lower cylinder portion  46  has a smaller diameter than an upper cylinder portion  47  which is located above it and of which the length, in the exemplary embodiment shown, corresponds approximately to twice the length of the lower (smaller) cylinder portion  46 . With the valve arrangement  32  closed, the valve pin  34  projects with a larger part of the lower cylinder portion  46  downwards out of the insert part  37 . A lower end region of the cylinder portion  46  of smaller diameter is provided with a continuous frustoconical bevel which forms the frustoconical sealing surface  35 . This sealing surface  35  matches a correspondingly formed, likewise frustoconical valve seat  33  in the region of the orifice  31  in the partition  27 . The frustoconical valve seat  33  is arranged continuously at the upper inner edge of an insert sleeve  48 . The insert sleeve  48  is inserted, water-tight, in a cylindrical recess of a continuous collar  49  of the partition  27 . The collar  49  is assigned to that side of the partition  27  facing the upper chamber  26  and surrounds the orifice  31  in the partition  27 . 
     The valve pin  34  is guided with its upper cylinder portion  47  (of larger diameter) so as to be capable of being moved up and down in a downwardly open blind-hole bore  50  in the insert part  37 . The blind-hole bore  50  has a continuous contraction  51  at the lower end. As a result, the inside diameter of the blind-hole bore  50  is contracted at the lower end of the insert part  37 , specifically approximately to the smaller diameter of the lower cylinder portion  46 . The dimensions of the valve arrangement  32  are such that, when the latter is in the closed state, the frustoconical sealing surface  35  at the lower end of the valve pin  34  can come into bearing contact over the entire area with the likewise frustoconically formed valve seat  33  on the upper inner face of the insert sleeve  48 , that is to say, with the valve arrangement  32  closed, a large-area frustoconical seal is provided between the insert sleeve  48  and the valve pin  34 . In this case, a step  52  between the cylinder portions  46  and  47  of the valve pin  34 , which have different diameters, does not rest against the contraction  51  at the lower end of the blind-hole bore  50  in the insert part  37  (FIG.  5 ). The length of that cylinder portion of the blind-hole bore  50  which guides the upper (larger) cylinder portion  47  of the valve pin  34  in the insert part  37  is substantially greater than the length of the upper cylinder portion  47 . In the exemplary embodiment shown, the cylindrical guide portion of the blind-hole bore  50  is approximately twice as long as the upper cylinder portion  47  of the valve pin  34 . As a result, particularly for scavenging the device, the valve pin  34  can penetrate completely, that is to say with the entire lower cylinder portion  46 , into the blind-hole bore  50  of the insert part  37 . Moreover, the blind-hole bore  50  of the insert part  37  affords sufficient space for receiving longer valve pins  34 . 
     With the insert part  37  pulled out of the sleeve  38 , the valve pin  34  is secured in said insert part against falling out by the contraction  51  of the lower end of the blind-hole bore  50 . Likewise, the maximum push-in depth of the valve pin  34  in the insert part  37  is limited by a continuous step  53  in the end region of the blind-hole bore  50 . 
     A part-region of the insert part  37  is provided with longitudinally directed slots  54 . In the exemplary embodiment shown, four slots  54  distributed uniformly over the circumference of the insert part  37  are provided. The slots  54  of equal size emanate from the open underside of the insert part  37  and extend to just short of the upper step  53  of the blind-hole bore  50 . 
     Transitional regions of the insert part  36  which are located within adjacent slots  54  can be widened elastically as a result of the slots  54 , to be precise form spring tongues  55 . It is thereby possible to widen the lower contraction  51  of the blind-hole bore  50  of the insert part  37  in such a way that, by virtue of the elastic widening of the spring tongue  55 , the valve pin  34  can be pulled with its cylinder portion  47  of larger diameter out of the insert part  37  and, if appropriate, inserted again. When the insert part  37 , together with the valve pin  34 , is inserted in the sleeve  38  of the housing  10 , the sleeve  38  holds the spring tongues  55  of the insert part  37  together, so that, with the valve arrangement  32  mounted, the valve pin  34  is held positively in the insert part  37 . 
     An attachment connection piece  56  branches off from the upper chamber  26  for the outflowing liquid. The attachment connection piece  56  is connected in one piece to the cover plate  14  of the housing  10 . A lower region of an elongate vertical tube  57  is pushed onto the attachment connection piece  56 . The tube  57  serves for bleeding the drinking appliance. A spring  58  surrounding the tube  57  on the outside serves for stabilizing the tube  57  and for protecting the latter against kinking. The tube  57  is formed preferably from transparent plastic, with the result that the water level in the tube  57  is visible and the pressure in the drinking appliance can thereby be determined visually. The upper open end of the tube  57  may be provided with a valve, not shown. This valve is capable of being closed when the drinking appliance is to be scavenged at higher pressure. 
     The device consists essentially of plastic. This applies, above all, to the housing  10 . By contrast, the valve pin  34  and the insert sleeve  48  are formed from a metallic material, in particular stainless steel. As a result, the surfaces serving for sealing the valve arrangement  32  consists of a resistant material capable of being accurately machined. 
     The method according to the invention for changing the pressure compensation ratio of the above-described device (gradient controller) proceeds as follows: 
     To be precise, since the valve  34 , by the force of its own weight, opens and closes the valve arrangement  32 , in order to set the appropriate pressure compensation ratio, the difference in pressure in the chamber  25  having the water inflow connection piece  17  in relation to the chamber  26  having the water outflow connection piece  18  must be coordinated with the inclination of the water supply conduit. A water supply conduit having a greater inclination requires a heavier valve pin  34  than a water supply conduit inclined to a lesser extent. For carrying out an appropriate setting, a valve pin  34  of appropriate weight is inserted in the insert part  37 . The valve pins  34  of different weight have upper cylinder portions  47  of different length. The length of the lower cylinder portion  46  of smaller diameter usually remains unchanged. 
     When a valve pin  34  is to be exchanged for another, then, first the securing shackle  40  is pivoted to the side, so that it frees the grip  42  of the insert part  37 . The insert part  37 , together with the valve pin  34 , can then be pulled upwards out of the sleeve  38 . After the insert part  37 , together with the valve pin  34 , is separated from the device, the valve pin  34  is pulled out of the insert part  37 , the spring tongues  55  separated by the slots  54  being bent outwards due to elastic deformation. At the same time, the contraction  51  at the lower end of the insert part  37  widens to an extend such that the valve pin  34  can be pulled downwards with the upper cylinder portion  47  of larger diameter out of the insert part  37 . Another valve pin  34  can then be pushed from below into the insert part  37 , the spring tongues  55  undergoing elastic deformation. By the spring tongues  55  subsequently being drawn together into the initial position, the valve pin  34  is secured against falling out of the insert part  37  by the contraction  51 . 
     By giving the length of the blind-hole bore  50  in the insert part  37  an appropriate dimension which is greater than is necessary for opening the valve arrangement  32 , it is possible for the insert part  37  to be assigned valve pins  34  of different length. In this case, the maximum length of the blind-hole bore  50  in the insert part  37  is selected such that the valve pin  34  having the greatest length is still capable of being moved up and down in the insert part  37  to a sufficient extent to open the valve arrangement  32 , specifically also for when the drinking appliance is scavenged. As a rule, the length of the blind-hole bore  50  is dimensioned such that the longest valve pin  34  is capable of being moved into the insert part  37  to an extend such that it is located completely in the latter. 
     In an alternative embodiment of the method, there is provision for exchanging the insert part  37 , together with the respective valve pin  34 , as a complete unit. In this case, it is not necessary to separate the valve pin  34  from the insert part  37  after the insert part  37  has been pulled out of the housing  10 . In this embodiment of the invention, if appropriate, the slots  54  of the cylindrical outer surface of the insert part  37  may be dispensed with, so that the guide for the valve pin  34  is completely cylindrical and has no spring tongues  55 . 
     A device according to a second exemplary embodiment (not shown) of the invention differs from the above-described device in the valve arrangement  32 . The valve arrangement in the device to be described here also has a valve pin. However, the latter is accommodated completely in an insert sleeve, specifically in such a way that it is capable of being moved up and down in the latter. The insert sleeve is fixedly arranged with a lower part in the collar of the partition. 
     The insert sleeve is stepped on the inside, to be precise has two different diameters there. An upper part of the insert sleeve having a larger diameter serves for receiving the valve pin. A lower part of the insert sleeve which approximately has the height of the collar has a smaller diameter. Located at the transition between the smaller and larger diameter is a preferably conical valve seat. The latter matches a sealing surface at the lower end of the valve pin, the valve pin resting sealingly with its sealing surface on the valve seat for the purpose of closing the valve arrangement. 
     A plurality of passage bores are arranged above the valve seat in the wall of the insert sleeve. Preferably, approximately four to eight passage bores of the same size are arranged so as to be distributed uniformly over the circumference of the outer surface of the insert sleeve. With the valve arrangement open, that is to say with the valve pin moved up, the water passes via the lower open end face of the insert sleeve into the interior of the latter and flows radially outwards, specifically approximately in the horizontal direction, through the passage bores in the outer surface of the insert sleeve which are completely or for the most part released by the valve pin. 
     In the device shown here, an upper part of the insert sleeve extends into a sleeve-like widening of the cover plate of the housing. This sleeve is designed to have a diameter larger than the outside diameter of the insert sleeve, so as to allow for, between the sleeve and the insert sleeve, an annular gap through which water can pass to the top side of the valve pin. The top side of the sleeve can be closed sealingly by means of a closure. By the cover being removed, the valve pin in the insert sleeve becomes accessible. In order to change the pressure compensation ratio, the valve pin can then be exchanged for another valve pin, in particular a heavier or lighter valve pin. After this exchange, the top side of the sleeve can be sealingly closed again by means of the closure on the cover plate.