Abstract:
A volumetric metering system for a seeding machine is provided with a plurality of movable inserts each insert defining a ledge over which the seed falls to the meter outlet. The inserts are selectively movable between an open position in which seed is allowed to flow over the ledge and a closed position in which the inserts close the product flow to the outlet. By locating the product shut-off after the meter but before product enters the distribution system, there will only be a short delay in stoppage of product flow once the shut-off is closed.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a continuation-in-part of U.S. application Ser. No. 12/481,254, filed 9 Jun. 2009. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to a volumetric seed meter and in particular to such a seed meter having sectional meter shut-off. 
       BACKGROUND OF THE INVENTION 
       [0003]    Volumetric meters are commonly used in agricultural seeding implements such as grain drills and air seeders to meter the seed. Volumetric meters are also used with fertilizer or other chemical applicators. A volumetric meter often employs a meter roller contained within a housing that defines an inlet for receiving product from a tank and an outlet for dispensing metered product. The meter roller is fluted so that as the roller is rotated, product from the tank is carried to the outlet in a controlled manner based on the size of the roller flutes and speed of rotation of the roller. From the meter housing, the seed is carried by a distribution system for dispensing to the soil. The distribution system typically includes a number of individual channels each receiving seed from a defined section of the meter roller. The distribution system may be a gravity system that guides the seed as it falls by gravity from the meter to the soil. Alternatively, the distribution system may be pneumatic, using flowing air to distribute the seed from the meter. A pneumatic distribution system typically has a plurality of primary distribution lines, each supplied with product from a defined section of the meter roller. Typically, product flowing through each primary distribution line is later divided into several secondary distribution lines, each directed to an individual crop row in the soil. 
         [0004]    In contrast to a volumetric seed meter, row crop planters use individual seed meters located at each row unit. These meters are supplied by either individual seed hoppers mounted to the row unit or supplied with seed from a central tank, often with a pneumatic system to deliver the seed. The seed meters, however, instead of metering the seed based on volume, singulate the seed and deliver one or more seeds upon specified intervals. Recent products have been made available on row crop planters that shut-off the flow of seed at the individual row units. This is often accomplished by a clutch mechanism in the seed meter drive that is actuated to disengage the seed meter drive. These have met with commercial success as customers seek to control costs by eliminating any double seeding such as can occur at the edge of a field when the area remaining to be seeded is not as wide as the planter or in a non-rectangular field where the rows do not all end at the same location. Since the seed shut-off is at the individual meter mounted on the row, there is only a short delay or no delay from the time the meter is shut-off until the flow of seed at the soil is stopped. 
         [0005]    To provide a similar shut-off on a volumetric meter having an air, i.e. pneumatic, distribution system, a number of unique challenges must be overcome that do not exist with a row crop planter. These challenges include: 1) if seed is stopped from flowing into the meter, there is a long delay until seed stops flowing at the discharge since the meter housing must empty before seed flow stops; 2) air seeders may mix multiple products within the airstream so that stopping the flow of seed to the ground by redirecting the air flow after the seed is introduced into the airstream requires separation of the mixed products; and 3) with some air seeders, the product tanks are pressurized during operation, further complicating the return of redirected product to the tank. 
         [0006]    One approach to providing a sectional meter shut-off is shown in US patent application publication number 2009/0079624, published Mar. 26, 2009. Slidable gates are positioned between the product storage tank and the meter roller. Individual actuators are provided to move each gate between open and closed positions. Because the gates are positioned between the storage tank and the meter, after actuation of the shut-off actuators, product will continue to flow until the meter is emptied of product. Thus this arrangement does nothing to address the first challenge listed above. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention utilizes the existing wear insert in the meter housing as a movable gate to shut-off the flow of product from the meter. The insert forms a ledge over which metered product flows to the meter housing outlet. Using the insert as the shut-off gate avoids the addition of a separate component to function as the gate. By placing the gate after the meter but before the distribution system, product flow will stop more quickly after shut-off then with the device shown in the above patent application as the meter housing does not first have to empty itself of product. Furthermore, by locating the gate before the distribution system, metered product is not mixed with the air stream or with additional products, causing a need for product redirection into a pressurized tank or separation of multiple products. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a side elevational view of an air seeder and tiling implement having the sectional meter shut-off of the present invention; 
           [0009]      FIG. 2  is a side sectional view of the seed meter of the air seeder shown in  FIG. 1  with the insert in the open position; 
           [0010]      FIG. 3  is a side sectional view of the seed meter shown in  FIG. 2  with the insert in the closed position; 
           [0011]      FIG. 4  is a side sectional view of another embodiment of the seed meter with the insert in the open position; and 
           [0012]      FIG. 5  is a side sectional view of the seed meter shown in  FIG. 4  with the insert in the closed position. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0013]    An air seeder constructed according to a preferred embodiment of the present invention is shown in the figures. With reference to  FIG. 1 , an air seeder is shown comprising of a seed cart  10  towed between a tractor (not shown) and a tilling implement  12 . The seed cart  10  has a frame  14  to which product tanks  16  and wheels  18  are mounted. Each product tank  16  has an associated metering system  20  at its lower end (only one of which is shown) for controlled feeding of product into a pneumatic distribution system  22  at a primary distribution manifold  24 . The tilling implement  12 , towed behind the seed cart  10 , consists generally of a frame  30  to which ground openers  32  are mounted. Incorporation of seed row finishing equipment such as closing wheels  34  is also desirable in many applications. 
         [0014]    The pneumatic distribution system  22  includes a centrifugal fan  36  connected to a plenum  38 , which is in turn connected to one or more primary distribution manifolds  24 , each associated with a product tank  16 . The individual passages in the primary distribution manifold  24  are each connected by a primary distribution line  40  to a riser tube  42 , only one of which is shown. Each riser tube  42  is in turn coupled to a secondary distribution header  44 . Secondary distribution lines  46  connect the secondary distribution header  44  to seed boots mounted on the ground openers  32  to deliver product, seed or fertilizer, etc. to the furrow formed by the openers  32 . While the air seeder of  FIG. 1  is shown as a separate air cart connected to a tilling implement, the product tanks  16 , metering system  20  and distribution system  22  can be mounted to the same frame as the ground openers  32 . 
         [0015]    The metering system  20  will now be described in greater detail with reference to  FIGS. 2-5 . Metering system  20  includes a housing  50  that forms a product inlet  52  coupled to a product tank  16  to receive product, such as seed, from the tank. The housing  50  further forms an outlet  54  through which metered seed falls to the primary manifold  24  of the pneumatic distribution system. 
         [0016]    A meter roller  72  is disposed in the housing  50 . The meter roller  72  is constructed of a plurality of roller segments  78  axially positioned along a drive shaft  80 . In the embodiment shown, the drive shaft  80  is hex shaped to mate with the hex shaped bore in the roller segments  78 . Inserts  82  are provided in the housing and form a ledge  84  at the outlet  52  over which seed falls into the outlet. The ledge can wear overtime from the product flowing over the ledge. Thus, the inserts are intended to be replaceable. Preferably there is one insert for each primary distribution line but more or fewer inserts can be provided. The inserts  82  are movably mounted in the housing  50  for linear movement between the open position shown in  FIG. 2  and a closed position shown in  FIG. 3 . Each insert includes an extension  86  that extends through a slot in the housing  50  to the exterior of the housing. Actuators  88  are mounted to the housing  50  and have extendable rods  90  coupled to each insert  82 . Preferably one actuator is provided for each insert, but fewer actuators can be used with each actuator controlling more than one insert. The actuator may be hydraulic, pneumatic, electric etc. In the normal operating position, the rod  90  is retracted and the insert is in the open position, allowing seed to flow over the ledge  84 . When actuated, the rod  90  is extended and moves the insert to the closed position in which the ledge  84  bears against the inner surface of the housing on the opposite side of the outlet  52 . This closes the outlet and prevents seed from flowing from the housing into the associated primary distribution line or lines. 
         [0017]    An alternative embodiment is shown in  FIGS. 4 and 5  where like components are given the same numerals as in  FIGS. 2 and 3  while modified components are given the same numeral with the addition of 100. The insert  182  slides along a curved path between the open and close positions rather than a straight path as shown in  FIGS. 2 and 3 . This provides a rotary motion generally about the axis of the shaft  80 . The insert has a mounting boss  192  that extends through the housing wall. The actuator  188  as an extendable rod  190  that is coupled to the mounting boss  192  by a pivot pin  194 . The actuator  180  is also pivotally mounted to allow the insert  182  to travel in a curved path while the rod  190  extends in a straight line. 
         [0018]    Preferably the actuator rod is spring biased to the retracted position so that the rod remains retracted when the actuator is in the non-energized state. The terms energized and non-energized mean when the actuating power is present or not present and can be electric, pneumatic, hydraulic, etc. The actuators are preferably electronically controlled. The actuators can be controlled selectively by the operator through a control panel in the tractor cab or, preferably, the actuators are controlled by field mapping software in combination with a vehicle positioning system such as GPS. With the use of field maps and vehicle positioning, the actuators will be activated to close product flow from the meter, and thus stop product flow to one or more of the distribution lines  40  which supply product to one or more rows of the tilling implement  12 , as the tilling implement covers area which has already been seeded, which will be seeded in a later pass, or which should not be seeded at all. 
         [0019]    The present invention uses the already existing insert as the shut-off gate. This avoids the need for a separate member to function as the gate. The shut-off for a volumetric meter of the present invention, located after the meter roller but before product has moved into the air stream, overcomes the challenges described above. The long delay between shut-off and the termination of product discharge at the row is reduced since the meter does not need to empty before product flow ceases. Since the product is stopped before the product enters the air stream, diversion of the product back to the tank is not needed. This avoids the need to separate mixed products and avoids the difficulty of returning product to a pressurized tank. While the invention has been shown and described in the context of an air seeder, it will be appreciated by those skilled in the art that the invention can be used with any volumetric meter such as a grain drill that uses gravity to distribute seed from the meter to the ground. 
         [0020]    Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims.