Patent Publication Number: US-2007113792-A1

Title: Feeding installation

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The invention relates generally to the invention relates to a feeding installation according to the preamble of claim  1 .  
      Such an installation is known from German patent application DE19756367-A1. This document discloses a metering device comprising several storage containers from which feed is capable of being metered in a mixing space. From this mixing space transport takes place to the feed troughs. Metering feed from the storage containers takes place by making the metering device meter at a particular number of revolutions per minute. A frequency generator per metering device generates for this purpose a three-phase current with a particular frequency.  
      2. Description of the Related Art  
      A problem with such an installation is that, in particular in the case of several metering devices, complex electric circuits are needed.  
      The invention aims at providing an installation of the above-mentioned type in which the metering devices are controlled in a simple manner.  
      This is achieved by means of a feeding installation of the above-mentioned type characterized in that several metering devices are capable of being energized individually by the converter. A converter is a relatively complex electric device. Owing to the fact that several metering devices can be operated by the same converter, less circuits are needed.  
      The converter is preferably a frequency converter. For the drive of metering devices it is possible to make use of standard three-phase motors. The number of revolutions per minute of these motors is adjustable by regulating the frequency of the alternating current applied.  
      In a particular embodiment according to the invention, each metering device is capable of being energized by the converter via a switch, the switch being operable by the control device. In this manner it is possible to operate the switch in such a way that it switches without being energized, which means: that the switch switches while no voltage is being applied to it. This prevents wear of the switch.  
      The feeding installation comprises in particular a mixing space, the metering device being suitable for adding feed from a storage container to the mixing space. In this manner it is possible to prepare an amount of feed composed of several sorts of feed in any desired proportion.  
      In a particular embodiment, the feeding installation comprises several troughs orientated around a central axis, the storage containers being located above the troughs. This provides a compact construction occupying little space in a stable.  
      The metering device preferably comprises an auger with an electric motor. Such a metering device is simple and robust.  
      In a further favorable embodiment, the metering device comprises monitoring sensors that are suitable for supplying a monitoring signal and the control device is controllable by the monitoring signal. This makes it possible to monitor automatically the metering device, so that action can be taken before the occurrence of damage to the device. These actions preferably take place automatically by means of the control device.  
      It is advantageous if the converter comprises the monitoring sensor. This renders separate sensors disposed on the motor of the metering device superfluous.  
      In a particular embodiment, the feeding installation is suitable for controlling the metering device in a direction opposite to the metering direction. This makes it possible that, in case of a blockage, the metering device operates in opposite direction, so that the blockage is obviated. This preferably takes place automatically after detection of a blockage.  
      In a further embodiment of the invention, the control device comprises a memory for storing metering device parameters and the metering device is controllable on the basis of the metering device parameters. Because the metering devices can differ from each other and/or meter different feed, for an optimum metering each metering device has to be controlled in a different manner.  
      In a still further embodiment of the invention, the feeding installation comprises a metering device suitable for metering feed directly from the storage container into the trough.  
     BRIEF SUMMARY OF THE INVENTION  
      The present invention addresses these problems by providing a ______  
      Another aspect of the invention comprises a method for ______ 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The features and advantages of the invention will be appreciated upon reference to the following drawings, in which:  
       FIG. 1  is a plan view of one embodiment of the invention showing diagrammatically the electric control of the feeding installation;  
       FIG. 2  is a sectional view of a feeding installation according to the invention. 
    
    
     DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS  
      The following is a description of certain embodiments of the invention, given by way of example only and with reference to the drawings. Referring to  FIG. 1 , shows diagrammatically a feeding installation  1  according to the invention, comprising a trough  2  ( FIG. 2 ) for offering feed to an animal, several storage containers  3 ,  4  ( FIG. 2 ), each provided with a metering device  15 A,  15 B,  15 C for metering an amount of feed, a converter  7  for generating an alternating current for controlling the metering device  15 A,  15 B,  15 C, and a control device  8  for controlling the converter  7 , several metering devices  15 A,  15 B,  15 C being capable of being energized individually by the converter  7 . Each metering device  15 A,  15 B,  15 C is capable of being energized by the converter  7  via a switch  9 A,  9 B,  9 C, the switch  9 A,  9 B,  9 C being operable by the control device  8 . The converter converts a signal into a current by means of which a motor is capable of being energized. The converter  7  shown is designed as a frequency converter, the number of revolutions per minute of the motor  5 ,  6  of the metering device  15 A,  15 B,  15 C being adjustable in dependence on the frequency of the alternating current by means of which the motor  5 ,  6  is energized. Other converters  7 , controlling a motor  5 ,  6  on the basis of for example a voltage or a block current, are possible as well.  
      The feeding installation  1  is connectable to a two-phase current source via a plug  16 . The frequency converter  7  known per se converts this two-phase alternating current into a three-phase alternating current by means of which the motors  5 ,  6  ( FIG. 2 ) of the metering devices  15 A,  15 B,  15 C are capable of being energized. The wires for the three-phase current are indicated in bold. By controlling the phase difference of the three phases of the outgoing alternating current in such a way, alternating voltages with different net frequencies are possible, so that the motor  5 ,  6  can be driven at the number of revolutions per minute corresponding to the frequency.  
       FIG. 2  is a cross-section of a feeding installation  1  according to the invention in the form of a feeding column. The feeding installation  1  comprises several troughs  2  orientated around a central axis A, the storage containers  3 ,  4  being located above the troughs  2 . The feeding installation  1  further comprises a mixing space  12 , the metering device  15 A,  15 B,  15 C being suitable for adding feed from a storage container  3 ,  4  to the mixing space  12 . Each metering device  15 A,  15 B,  15 C comprises an auger  13 ,  14  with an electric motor  5 ,  6 . Here the auger  13 ,  14  is disposed directly on the axis of the electric motor  5 ,  6 . The entire feeding column is built up around a frame  21 .  
      The bottom of the mixing space  12  is in the form of a flap  19 . At the lower side of the mixing space  12  there is disposed a pipe-shaped chute  20  that is rotatable about the central axis A. By rotation about said axis the pipe-shaped chute  20  can lead the feed into a selected trough  2 .  
      The feeding installation  1  comprises monitoring sensors  17 ,  18  that are suitable for supplying a monitoring signal, the control device  8  being controllable by the monitoring signal. A monitoring sensor  17 ,  18  is designed as a temperature sensor. A second monitoring sensor  17 ,  18  in the form of a torque sensor is disposed on the motor  5 ,  6  for measuring the drive torque of the motor  5 ,  6 . The converter  7  can also comprise the monitoring sensor  17 ,  18 . The signals the converter  7  receives for regulating the frequency are compared with standard values. A too great deviation can be an indication of a malfunction.  
      The feeding installation  1  is suitable for controlling the metering device  15 A,  15 B,  15 C in a direction opposite to the metering direction R. This makes it possible that, if the monitoring sensors  17 ,  18  detect a blockage, the control device  8  controls the converter  7  in such a way that the outgoing three-phase alternating voltage effects that the direction of rotation of the auger  13 ,  14  is reversed. As a result of this, the blockage will be rotated back into the storage container  3 ,  4 . After an adjustable number of revolutions in opposite direction, it will be possible again to control the auger  13 ,  14  in the normal metering direction R. It is also possible to use the reversing device in an alternating manner for the purpose of mixing the feed in the storage container  3 ,  4 .  
      The control device  8  comprises a memory for storing metering device parameters, the metering device  15 A,  15 B,  15 C being controllable on the basis of the metering device parameters. Metering device parameters are, for example, starting torque, starting speed, metering speed or maximum load. This makes it possible to control the motor  5 ,  6  of the metering device  15 A,  15 B,  15 C using the optimum parameters. For example, the controlling speed of the metering device  15 A,  15 B,  15 C will depend on the type of feed in the storage container  3 ,  4 . Sticky and viscous feed will then be metered at a lower metering speed.  
      In a non-shown embodiment of the feeding installation  1 , the feeding installation  1  comprises a metering device  15 A,  15 B,  15 C suitable for metering feed directly from the storage container  3 ,  4  into the trough  2 . Said metering device  15 A,  15 B,  15 C and said storage container  3 ,  4  are particularly suitable for roughage, such as chopped maize and potatoes. Handling roughage requires stronger drives and larger passages. Besides, said storage container comprises an agitator for preventing blockages, which agitator is drivable simultaneously with the auger of the metering device  15 A,  15 B,  15 C. There is disposed a second metering device  15 A,  15 B,  15 C for metering concentrate from a concentrate silo into a mixing space  12 . Said mixing space  12  serves as an intermediate storage space and comprises its own metering device  15 A,  15 B,  15 C for metering concentrate into the trough  2 . The electric motors  5 ,  6  of said three metering devices  15 A,  15 B,  15 C are capable of being energized by the converter  7 .  
      The mode of operation of the feeding installation  1  is as follows. An animal reports at the feeding installation  1  and is recognized in a known manner by the animal identification device  22 . The control device  8  retrieves the data of the animal from the memory and determines on the basis thereof the sort and the amount of feed for the animal. Subsequently, the amount of a particular ingredient is converted into the number of revolutions of the auger  13 ,  14  of the respective storage container  3 ,  4 , for example storage container  3 . Switch  9 B is closed so that the frequency converter  7  will be connected with the relevant motor  5  of the metering device  15 B. Subsequently, the frequency converter  7  is controlled in such a way that the motor  5  will make the desired number of revolutions at the desired speed. The ingredient transported by the auger  13  is metered in the mixing space  12 . The frequency converter  7  is put out of operation, the switch  9 B is opened, and subsequently the process starts again for the ingredient in storage container  4 . The pipe-shaped chute  20  is moved into the position of the trough  2 , after which the portion in the mixing space  12  consisting of the ingredients from storage containers  3  and  4  is dropped into the pipe-shaped chute  20  by opening the flap  19 . The flap  19  is closed again, after which a next portion of mixed feed is prepared, if desired.  
      By contamination and/or blockage the temperature in a motor  5 ,  6  can rise to a too high level. This is detected by a temperature sensor  17  near the motor  5 ,  6  and the value is passed on to the control device  8 . When a particular temperature is exceeded, the motor  5 ,  6  is put out of operation. This also happens when a particular measured torque is exceeded. The torque sensor  18  can also be used to detect whether there is still feed in a storage container.  
      The invention is not limited to the described embodiment of a feeding column with a mixing space  12 , but can also be applied, for example, in a milking robot that is suitable for supplying several sorts of feed.  
      Furthermore, the invention is not limited to a metering device  15 A,  15 B,  15 C operating via an auger  13 ,  14 , but may comprise various embodiments, such as a conveyor belt, a metering disc or a metering pump. In the latter case, the device is suitable for supplying liquid and viscous substances, such as molasses.  
      Instead of each metering device  15 A,  15 B,  15 C being energized individually, it is also possible for several metering devices  15 A,  15 B,  15 C to be energized simultaneously by the converter  7  by means of the same signal. In this manner it is possible to meter simultaneously from several storage containers  3 ,  4 .  
      Thus, the invention has been described by reference to certain embodiments discussed above. It will be recognized that these embodiments are susceptible to various modifications and alternative forms well known to those of skill in the art. For example, the ______ may be modified by ______  
      Many modifications in addition to those described above may be made to the structures and techniques described herein without departing from the spirit and scope of the invention. Accordingly, although specific embodiments have been described, these are examples only and are not limiting upon the scope of the invention.