Abstract:
Sowing heart for a single-grain sowing machine comprising: a sowing disk rotatable in a rotational direction R, the sowing disk having at least two sowing hole series, arranged concentrically to the sowing disk, with sowing holes, a receiving area for receiving seed at the sowing holes and a dispensing area for dispensing seed, in front of the dispensing area, a wiping device is provided for singulating seed at the sowing holes during the operation of the sowing heart, which has a first wiping element for the first sowing hole series and a second wiping element for the second sowing hole series, whereby the wiping elements are coupled and are designed to be adjustable with respect to one another. In addition, the invention relates to a single-grain sowing machine with a considerable number of sowing aggregates, in each case with an above-mentioned sowing heart and a corresponding wiping device.

Description:
FIELD OF THE INVENTION 
     The invention relates to a sowing heart, a wiping device, and a single-grain sowing machine. 
     BACKGROUND OF THE INVENTION 
     Known sowing hearts for pneumatic single-grain sowing aggregates consist in general of two halves, namely a rear part, in which the mount of the sowing disk and the negative pressure area are installed, and a front part, into which the lower outlet of the seed container leads and which itself has a seed reservoir. 
     In sowing holes of the sowing disk matched to the size of the seed, which holes are arranged at specific intervals on a circle as a sowing hole series, individual grains of seed are removed from the seed reservoir and thrown off in a dispensing area by interrupting the negative pressure. If the interruption of the negative pressure is not sufficient to ensure dropping, an automatic wiper is provided at a short distance behind the ideal dropping spot. Per sowing disk, several sowing hole series can be arranged in circles of the sowing disk that are separated from one another. 
     In order to drop only one grain of seed if possible with each dropping, singulating devices are provided for each sowing hole series. In the case of a single seed, these devices work relatively reliably but hit their limits specifically in the case of tough seed, for example carrot seeds. 
     SUMMARY OF THE INVENTION 
     The object of this invention is therefore to provide a wiping device and a sowing heart with a wiping device as well as a corresponding single-grain sowing machine, with which a reliable singulation of the seed, even in the case of complicated seed, is made possible. 
     This object is achieved with a sowing heart, a wiping device and a single-grain sowing machine, as defined by the independent claim(s). Advantageous further developments of the invention are indicated in the subclaims. All combinations of at least two features disclosed in the specification, the claims and/or the figures fall within the scope of the invention. 
     The basic idea of this invention is to provide a wiping device with at least two wiping elements that can be attached together and can be adjusted to one another for wiping surplus seed at sowing holes. During the operation of the sowing heart, the wiping elements wipe by rotation of the sowing disk along the sowing holes arranged on the sowing hole series. In this case, the wiping elements are arranged in such a way that only surplus seed is removed from each sowing hole; in each case, however, one grain of seed per sowing hole gets stuck. As a result of the wiping elements being able to be adjusted with respect to one another, but at the same time being able to be fixed on one another or relative to one another, an optimal adjustment of the two wiping elements relative to the sowing hole series of the sowing disk is possible. 
     Within the scope of this disclosure and under the term seed, for example, fertilizer, grains, whether processed or in raw form, can be subsumed. 
     According to an advantageous embodiment of the invention, it is provided that the wiping elements can be designed to be adjustable with respect to one another, in particular exclusively, in the radial direction of the sowing disks and parallel to the sowing disk. In this respect, the setting of the wiping elements is greatly simplified, since the degrees of freedom of the adjustment of the wiping elements in the radial direction are limited to the sowing disk. The setting or adjustment within the radial direction is decisive for the optimal singulating of the seed at the seed holes. 
     The function of the wiping elements is further improved by having the latter be spring-loaded, in particular together, in a direction orthogonal to the sowing disk. Thus, it is prevented that flat seed moves under the wiping elements or the function of the wiping elements would no longer be ensured because of wear and tear of the wiping elements. Thus, a long-lived operation of the wiping elements and thus the sowing heart with larger maintenance intervals is possible. 
     In further development of the sowing heart according to the invention, it is provided that the wiping elements can be designed to be adjustable with respect to one another by a conversion of a rotational motion of an adjustment device into a translational motion of the wiping elements in the radial direction. In this way, the adjustment, in particular by an electric motor, can be automated. 
     In this case, it is advantageous, according to the invention, when for the adjustment of the wiping elements, in particular in the radial direction and/or with respect to the contact pressure at the sowing disk, a control circuit is provided. As a set value, in particular the signal of an evaluation/detection of the sowing holes, preferably video monitoring, is used. The video monitoring is performed in particular by a monitoring device that is integrated in the sowing heart in such a way that the monitoring of seed production can be done directly in the organ responsible for the singulating, namely the sowing heart. In this case, another aspect of this invention is to provide the monitoring in an economical, quickly-responding and compact manner by a line scan camera, in particular by pure contrast measurement. It is especially advantageous in this invention that the monitoring can be carried out only on one side of the sowing disk, namely in particular by reflection measurement. In other words: electromagnetic waves directed from a radiation source to the sowing disk are reflected by the sowing disk and detected by the line scan camera after reflection, specifically in the area in which the seed is conveyed to the sowing disk. The line scan camera is focused corresponding to the reflective surface of the sowing disk, and the pulses produced by the line scan camera are evaluated by an evaluating unit, whereby clearly different pulses are obtained at the sowing holes depending on whether zero or one or two sowing grains adhere to the sowing hole. Thus, the coating of each sowing hole immediately after detection, i.e., in-line, can be evaluated and can serve as a correcting value for the control circuit for adjusting the wiping elements. 
     According to another advantageous embodiment of the invention, it is provided that the first wiping element has a first holding plate and a first wiper that is attached, in particular removably, on the first holding plate, and the second wiping element has a second holding plate and a second wiper that is attached, in particular removably, on the second holding plate. 
     Thus, the wiping elements can be integrated in a compact manner optimally in a working space of the sowing heart despite the enhanced functionality of the wiping elements. 
     In this case, it is especially advantageous when the second holding plate is designed to run through the first holding plate. 
     The wiping elements are further developed according to the invention by the second holding plate, in particular with an outside contour of the second holding plate at an inside contour of the first holding plate, being guided to slide along the first holding plate in the radial direction of the sowing disk. Thus, an expensive mechanism can be eliminated, so that the production of the wiping device is simple, and a long-lived operation can be ensured without maintenance of the wiping device being necessary. 
     By the first holding plate and/or the second holding plate at the reverse sides facing away from the wipers having spring elements for spring-loading the first wiping element and/or the second wiping element, the above-described advantages of a spring can also be integrated in the sowing heart in a simple and compact way. 
     In another advantageous embodiment of the invention, it is provided that the first holding plate has a first actuator intake for receiving a first actuator of the adjustment device, and the second holding plate has a second actuator intake for receiving a second actuator of the adjustment device. The actuators can preferably be designed as pins that engage in corresponding recesses in the holding plates, in particular designed as slots. 
     In this case, it is of special advantage when the first actuator and/or the second actuator are arranged in a manner that in particular can be controlled separately and rotated eccentrically on the adjustment device. The adjustment thus is done with simple mechanical means, which are maintenance-free and can be controlled exactly. 
     In further development of the wiping elements according to the invention, it is provided that the first wiper has a first runner and is connected to the first holding plate by at least two arms that are separated from one another and/or the second wiper has a second runner and is connected to the holding plate by at least two arms that are separated from one another. According to the invention, it is also conceivable that one of the two wipers is connected to only one arm, in particular the wiper, which is attached to the second holding plate, if the latter is designed to run through the first holding plate. 
     In this case, it is of special advantage for the function of the wiping device when the first runner and/or the second runner, in particular in the opposite direction, are prestressed relative to a plane defined by the sowing disk and/or each have a curvature running in particular in the opposite direction. The contact pressure of the wipers produced by the curvature or prestressing, in particular at a front edge arranged against the rotational direction of the sowing disk, minimizes the problem that the seed will go under the wiper and jam there and may cause a malfunction. 
     It is especially advantageous when the curvature is uniform along the runners. 
     As an independent invention, a wiping device as well as a single-grain sowing machine are also disclosed, whereby features of the sowing heart and/or features of the wiping device and/or features of the single-grain sowing machine are to be considered as disclosed in each case and as transferable to the other invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Additional advantages, features and details of the invention follow from the description below of embodiments that are preferred as well as based on the drawings. The latter show in: 
         FIGS. 1 a  and 1 b   : Perspective views of a single-grain sowing aggregate of a single-grain sowing machine according to the invention obliquely from the rear ( FIG. 1 a   ) and obliquely from the front ( FIG. 1 b   ), 
         FIGS. 2 a  and 2 b   : Perspective views of a half of a sowing heart according to the invention, 
         FIGS. 3 a  and 3 b   : Perspective views of a wiping device according to the invention obliquely from the front ( FIG. 3 a   ) and obliquely from the rear ( FIG. 3 b   ), 
         FIGS. 4 a  and 4 b   : Perspective views of the wiping device according to  FIGS. 3 a  and 3 b   , and 
         FIGS. 5 a  and 5 b   : Perspective views of the function of the wiping element according to the invention. 
     
    
    
     In the figures, the same components and components with the same function are identified with the same reference numbers. 
     DETAILED DESCRIPTION OF THE INVENTION 
     In  FIGS. 1 a  and 1 b   , a sowing aggregate  1  of a single-grain sowing machine according to the invention is depicted, which sowing aggregate is fastened via an arm  2  to the frame of the single-grain sowing machine. Consequently, the direction of travel during operation of the single-grain sowing machine is in the direction indicated by the arrow F. 
     A sowing heart  3 , a tank  4  arranged above the sowing heart  3 , a sowing coulter  5  arranged below the sowing heart  3 , as well as two blade wheels  6  that can pivot relative to the sowing heart  3  and that are arranged in the direction of travel F in front of and behind the sowing heart  3  are attached at the arm  2 , which allows a pivoting motion, preferably as a vertical motion by designing the arm  2  as a parallelogram arm. 
     The tank  4  can be closed by a cover  4   d  and can be filled with seed, which in turn is guided laterally into the sowing heart  3  via a channel  4   k.    
     The seed is singulated in the sowing heart  3  and is laid down via the sowing coulter  5  in a furrow in the farmland opened by a coulter tip  7  of the sowing coulter  5 . 
     In  FIGS. 2 a  and 2 b   , the inner workings of a half  3   h  of the sowing heart  3 , shown in  FIG. 1 a   , are depicted, while the inner workings of the corresponding half  3   v  (see  FIG. 1 b   ) are not depicted. A working space  8  enclosed by the two halves  3   h  and  3   v  is divided by a sowing disk  40  into a pressure chamber and a seed chamber. 
     The pressure chamber is divided up by a sealing ring into a negative pressure area and a normal pressure area. In this case, the essential point is that a pressure difference, which is resolved in the normal pressure area, prevails in the negative pressure area at sowing holes  41  of the sowing disk  40  that are used for receiving and dispensing seed, whereby the seed is thrown off when passing over the sowing holes  41  from the negative pressure area into the normal pressure area and by rotational motion of the sowing disk  40  in a rotational direction R of the sowing disk  40 . 
     The negative pressure area is supplied with negative pressure by a pump, not shown, or a negative pressure blower. 
     The sowing holes  41  are arranged divided into two sowing hole series  42 ,  43 , in particular running parallel, in one concentric circular path each of the sowing disk  40  at defined intervals on the periphery of the sowing disk  40 . 
     The decisive component for this invention, namely a wiping device  10 , is arranged in the working space  8  in the rotational direction R behind an intake  9  of the channel  4   k . At this point, the sowing holes  41  are already provided with seed by the negative pressure prevailing at the sowing disk  40 . The wiping device  10  is used to cingulate sowing holes  41  provided in multiple ways with grains of seed, so that in the ideal case, exactly one grain of seed adheres to each sowing hole  41 . 
     The wiping device  10  has two wiping elements  11 ,  12  that can move against one another. The first wiping element  11  is comprised of a first holding plate  13 , which is fastened by fastening means  24  with two degrees of freedom to the half  3   h  of the sowing heart  3 . One degree of freedom is in the radial direction of the sowing disk  40 , and the second degree of freedom is in the axial direction to the sowing disk  40 , i.e., orthogonal to the sowing disk  40 . The degree of freedom in the axial direction is preferably limited by spring means. 
     In the rotational direction of the sowing disk  40 , the first holding plate  13  and thus the first wiping element  11  do not have any degree of freedom. The degree of freedom in the radial direction is limited in particular in that the fastening means are designed as screws, along whose shaft the first wiping elements  11  are guided into slots  25  corresponding to the fastening means  24 . The slots  25  are arranged aligned with one another, in particular at an upper end and a lower end of the first holding plate  13 . 
     On its side facing the sowing disk  40 , the first wiping element  11  has a first wiper  15  that is in particular runner-like. The latter is preferably formed from a first runner  17 , which can be clipped via two arms  19 ,  20  to the first holding plate  13  (see  FIGS. 5 a  and 5 b   ). 
     The arms  19 ,  20  are arranged at the two opposite ends of the first runner  17 , in the rotational direction R, whereby the first runner  17  preferably has a prestressing by curvature of the first runner  17  that is convex to the sowing disk  40 . The prestressing and curvature can be provided by the arrangement of the arms  19 ,  20  that can be clipped in particular to the holding plate  13  and/or by the corresponding shape of the first runner  17 . 
     In addition, the first wiping element  11  has a receiving opening  27 , arranged in particular between the slots  25 , for receiving, guiding and fixing the second wiping element  12 . The receiving opening  27  is designed as an essentially rectangular inside contour with two opposite guide surfaces  28  parallel to the radial direction of the sowing disk  40 . 
     The second wiping element  12  is comprised of a second holding plate  14 , onto which an in particular clipped second wiper  16  is attached. The second wiper  16  in particular has a second runner  18 , which is attached via arms  21 ,  22  to the second holding plate  14 . The second runner  18  essentially runs parallel to the first runner  17 . In contrast to the first wiper  15 , the second wiper  16  is arranged in particular in a middle third of the second runner  18 , i.e., at a distance from the two opposite ends in the rotational direction of the sowing disk  40 . In particular, the second wiper  16  has a convex prestressing and/or curvature preferably in the direction of the sowing disk  40 . 
     The second wiping element  12  has two slots  26  that correspond in particular to the slots  25  of the first wiping element  11  and that preferably are arranged at the fastening means  24  for attachment to the half  3   h  of the sowing heart  3  and act in combination with the latter. 
     Between the slots  26 , the second holding plate  14  has a shape  29 , corresponding to the receiving opening  27 , with parallel side walls  30 . The side walls  30  act as glide surfaces for guiding the second wiping element  12  along the guide surfaces  28  of the first wiping element  11 . 
     The second wiping element  12  accordingly also has two degrees of freedom analogously to the degrees of freedom of the first wiping element  11 . 
     The first wiper  15  is removable by first fastening means at the first holding plate  13 , and the second wiper  16  is removable by second fastening means at the second holding plate  14 , attachable or attached, in particular clippable or clipped. 
     In each case, on the wiper side, the fastening means is comprised of parallel arms  44 ,  45  that face each other, and in each case, on the holding plate side, the fastening means is comprised of in particular rounded, preferably circular-cylindrical attaching profiles  46  that can be encompassed by the arms  44 ,  45 . In particular, on the holding plate side, the fastening means have, moreover, in each case a recess  47  that accommodates the attaching profiles  46  and that limits the arms  44 ,  45  parallel to the holding plate  13 ,  14 . This recess serves to limit the degrees of freedom of the connection between the wipers  15 ,  16  and the holding plates  13 ,  14  to a single degree of freedom orthogonal to the respective holding plate  13 ,  14  or to the sowing disk  40 . The attaching profiles  46  are designed in particular in a rotationally symmetrical manner, preferably with an axis of rotation that is oriented or can be oriented radially to the sowing disk  40 . 
     In  FIG. 4 b   , it is shown that the first wiping element  11  and the second wiping element  12  at their sides facing away from the sowing disk  40  are spring-loaded in the direction of the sowing disk. Cylindrical pins  31  that project orthogonally in particular at the first holding plate  13  and the second holding plate  14 , on which spiral springs  32  can be put, serve as spring means. In the installed state, the spiral springs  32  preferably rest against an inside wall of the half  3   h  of the sowing heart  3 . 
     For adjusting the first wiping element  11  and the second wiping element  12  by means of the adjustment device  23 , the first wiping element  11  has an in particular arc-shaped slot  33 , in which a first actuator, designed in particular as an actuating pin  36  that rotates eccentrically around an actuating axis  35  of the adjustment device  23 , is designed in an engaging manner. 
     The second wiping element also has an in particular bent slot  34  for receiving a second actuator of the adjustment device  23 , rotating around the actuating axis  35  and designed in particular as a rotating actuating pin  37 . 
     By the rotation of the actuating pins  36 ,  37 , arranged eccentrically around the actuating axis  35 , the wiping elements  11 ,  12  are movable by limiting their degrees of freedom in the radial direction and thus can be adjusted to one another if the actuating pins  36 ,  37  can be controlled separately from the adjustment device  26 . The setting can also be done manually and can be attached in the desired position. 
     In this case, the positioning of the wiping elements  11 ,  12  is done in such a way that wiping edges  38 ,  39 , in particular designed in a wavelike pattern, of the runners  17 ,  18  are directed past the sowing holes  41  during the rotation of the sowing disk  40  in such a way that seed adhering to the sowing holes  41  is singulated. 
     LIST OF REFERENCE SYMBOLS 
     
         
           1  Sowing aggregate 
           2  Arm 
           3  Sowing heart 
           3   v  Half 
           3   h  Half 
           4  Tank 
           4   d  Cover 
           4   k  Channel 
           5  Sowing coulter 
           6  Blade wheels 
           7  Coulter tip 
           8  Working space 
           9  Intake 
           10  Wiping device 
           11  First wiping element 
           12  Second wiping element 
           13  First holding plate 
           14  Second holding plate 
           15  First wiper 
           16  Second wiper 
           17  First runner 
           18  Second runner 
           19 ,  20  Arms 
           21 ,  22  Arms 
           23  Adjustment device 
           24  Fastening means 
           25  Slots 
           26  Slots 
           27  Receiving opening 
           28  Guide surfaces 
           29  Shape 
           30  Side walls 
           31  Pins 
           32  Spiral springs 
           33  Slot 
           34  Slot 
           35  Actuating axis 
           36  Actuating pin 
           37  Actuating pin 
           38  Wiping edge 
           39  Wiping edge 
           40  Sowing disk 
           41  Sowing holes 
           42  First sowing hole series 
           43  Second sowing hole series 
           44  Arms 
           45  Arms 
           46  Attaching profile 
           47  Recess 
         R Rotational direction