Patent Publication Number: US-2010116185-A1

Title: Seed meter with flexible seed disc

Description:
This is a division of U.S. patent application Ser. No. 11/781,483 entitled “SEED METER WITH FLEXIBLE SEED DISC, filed Jul. 23, 2007, which is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to agricultural seeding machines and more particularly to seed meters used to meter seeds for placement in a seed trench. 
     BACKGROUND OF THE INVENTION 
     An agricultural seeding machine such as a row crop planter or grain drill places seeds at a desired depth within a plurality of parallel seed trenches formed in soil. In the case of a row crop planter, a plurality of row crop units are typically ground driven using wheels, shafts, sprockets, transfer cases, chains and the like. Each row crop unit has a frame which is movably coupled with a tool bar. The frame may carry a main seed hopper, herbicide hopper and insecticide hopper. If a herbicide and insecticide are used, the metering mechanisms associated with dispensing the granular product into the seed trench are relatively simple. On the other hand, the mechanisms necessary to properly meter the seeds, and dispense the seeds at predetermined relative locations within the seed trench are relatively complicated. 
     The mechanisms associated with metering and placing the seeds generally can be divided into a seed metering system and a seed placement system which are in series communication with each other. The seed metering system receives the seeds in a bulk manner from the seed hopper carried by the frame. Different types of seed metering systems may be used, such as seed plates, finger plates and seed disks. In the case of a seed disk metering system a seed disk is formed with a plurality of seed cells spaced about the periphery of the disk. Seeds are moved into the seed cells with one or more seeds in each seed cell depending upon the size and configuration of the seed cell. A vacuum or positive pressure air differential may be used in conjunction with the seed disk to assist in movement of the seeds into the seed cell. The seeds are singulated and discharged at a predetermined rate to the seed placement system. 
     The seed placement system may be categorized as a gravity drop system or a power drop system. In the case of the gravity drop system, a seed tube has an inlet end which is positioned below the seed metering system. The singulated seeds from the seed metering system merely drop into the seed tube and fall via gravitational force from a discharge end thereof into the seed trench. The seed tube may have a rearward curvature which reduces bouncing of the seed as it strikes the bottom of the seed trench. 
     Seed metering systems as described above are generally effective for seed singulation and seed spacing control. However, certain operating conditions such as side hills, etc. adversely affect the seed singulation and seed spacing. The seed pool area within the seed meter is at the bottom of the meter, and the rotating seed disc lies along side the seed pool. When the seeds shift laterally away from the seed disc during a side hill condition, seed singulation and/or seed skip problems can occur resulting in undesirable seed spacing in the seed trench formed in the soil. 
     What is needed in the art is a seeding machine with a seed metering system that provides good seed singulation and seed spacing during a wide range of operating conditions. 
     SUMMARY OF THE INVENTION 
     The invention in one form is directed to a seed meter for use in an agricultural seeding machine, including a housing having an inner chamber and one or more deflectors within the inner chamber, and a seed disc rotatably carried by the housing. The seed disc includes at least a portion thereof formed from a flexible material which is deflectable by the one or more deflectors during rotation within the housing. 
     The invention in another form is directed to a seed disc for use within a seed meter of an agricultural seeding machine. The seed disc includes a substantially rigid hub and a disc extending radially from the hub. The disc includes at least a portion thereof formed from a flexible material which is laterally deflectable during rotation within the seed meter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a row crop unit in an embodiment of an agricultural seeding machine of the present invention; 
         FIG. 2  is a perspective view of the seed meter on the row crop unit of  FIG. 1 , with part of the housing removed, and illustrating flexing of the seed disc; 
         FIG. 3  is a bottom view of the seed meter of  FIG. 2 , with part of the housing removed, and illustrating flexing of the seed disc; 
         FIG. 4  is a perspective view of the seed meter shown in  FIGS. 1-3 , with the seed disc removed to expose the deflectors; 
         FIG. 5  is another perspective view of the seed meter shown in  FIGS. 1-4 , with the seed disc removed to expose the deflectors; and 
         FIG. 6  is side view of the seed disc in a flexed state. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings, and more particularly to  FIG. 1 , there is shown a portion of an embodiment of an agricultural seeding machine  10  of the present invention. In the embodiment shown, seeding machine  10  is in the form of a row crop planter but may also be in the form of a grain drill, etc.  FIG. 1  illustrates a single row crop unit  12  of a multi-row planter, with each row crop unit  12  being substantially identical and connected to a common tool bar  14 . Only a single row crop unit  12  is shown and described below for simplicity sake. 
     Row crop unit  12  includes a multi-part frame  16  which is attached to tool bar  14  by parallel linkage  18 . Tool bar  14  is coupled to a traction unit (not shown), such as an agricultural tractor. For example, tool bar  14  may be coupled to an agricultural tractor using a draw bar or  3 -point hitch assembly. Tool bar  14  may be coupled with transport wheel assemblies, marker arms, etc. which may be of conventional design and not shown for simplicity sake. 
     Frame  16  carries a double disc furrow opener  20  for forming a seed trench in soil. An optional coulter wheel  22 , particularly for use in no till situations, may be placed ahead of double disc furrow opener  20 . A pair of gauge wheels  24  are respectively associated with the pair of discs of double disc furrow opener  20 . More particularly, each gauge wheel  24  is positioned generally in line with and immediately adjacent to the outside of each respective disc of double disc furrow opener  20 . Each gauge wheel  24  may be vertically adjusted to adjust the depth of the trench which is cut into the soil using double disc furrow opener  20 . 
     A pair of closing wheels  26  are also carried by frame  16 . Closing wheels  26  are positioned generally in line with double disc furrow opener  20 . Closing wheels  26  are preferably biased in a downward direction and have a peripheral edge with a shape which may vary, depending upon the application. 
     A seed metering system  28  and a seed placement system  30  are also carried by frame  16 . Seed placement system  28  is in the form of a gravity drop seed tube, but could be configured differently, such as a power drop seed placement system with a powered wheel, etc. 
     Seed metering system  28  receives seed from a main seed supply, such as seed from a distant main seed hopper which is supplied via air or the like, or a seed hopper carried above frame  16 . Seed metering system  28  generally includes a seed meter  32  driven by a rotatable cable drive  34 . Cable drive  34  includes a flexible drive cable driven by a common drive shaft at the rear of toolbar  14 . Such a cable drive is marketed as a “Pro-Shaft” drive on the Pro-Series XP planter which is manufactured and sold by the assignee of the present invention. It will be understood, however, that other types of mechanical, electrical and/or hydraulic drives for seed meter  32  can be utilized. 
     Seed meter  30  ( FIGS. 2-6 ) includes a multi-part housing  36 , with a first housing part  36 A and a second housing part  36 B defining an inner chamber  38  therein. Within inner chamber  38  is a seed pool area  38 A and an outlet  38 B. Housing  36  rotatably carries a drive shaft  40 , which in turn is concentrically coupled with and drives a seed disc  42 . Drive shaft  40  has an axis of rotation  44  which also defines an axis of rotation of seed disc  42 . Seed disc  42  has a plurality of seed cells  46  intermittently spaced about the periphery thereof. A vacuum source (not shown) applies vacuum pressure to seed cells  46  formed in seed disc  42 . This vacuum pressure promotes entry of the seeds into seed cells  46  and maintains the seeds in place within seed cells  46 . Seeds are transported from seed cells  46  to seed placement system  28 . Of course, seed meter  32  may be configured with a positive pressure to assist in seed movement rather than a vacuum pressure. 
     According to an aspect of the present invention, seed disc  42  includes at least a portion thereof formed from a flexible material which is deflectable by one or more deflectors  48  during rotation within housing  36 . More particularly, seed disc  42  includes a rigid hub  50  and a flexible disc  52  extending radially from hub  50 . Hub  50  is formed from a rigid material, such as steel or a rigid plastic. In the embodiment shown, flexible disc  52  is flexible the entire radial extent from hub  50  to the outer periphery. However, flexible disc  52  can also be partially flexible in one or more isolated portions, such as radial rings or angular sections, etc. Flexible disc  52  can be formed from any type of flexible material providing a desired degree of flexure, such as urethane, thin stainless steel, rubber and/or plastic. 
     Deflectors  48  may have any suitable shape which functions to deflect flexible disc  52  of seed disc  42  at desired locations within inner chamber  36 . For example, each deflector  48  may be in the form of a ramped surface (as shown), one or more rollers shown in dashed lines as  48 A, and/or one or more fingers shown in dashed lines as  48 B, etc. Deflectors  48  are integral with housing  36 , or may be separate from and attached to housing  36 . In the embodiment shown, two deflectors  48  are provided within housing  36 , one being positioned in association with seed pool area  38 A and the other deflector being positioned in association with outlet  38 B. 
     During use, a selected seed type is received from a main seed supply at seed meter  32 . The seed is maintained against a side of seed disc  42 , and received within seed cells  46 . To assist seed movement into seed cells  46 , a vacuum pressure is applied to the opposite side of seed disc  42  using a suitable vacuum source. Of course, a positive pressure may also be applied to the side of seed disc  42  at which the seeds are disposed. Each seed disc  42  of each seed meter  32  is driven using a corresponding cable drive  34  from a common drive shaft carried behind tool bar  14 . As seed disc  42  rotates, it is laterally deflected in the regions of seed pool area  38 A and outlet  38 B by corresponding deflectors  48 . Seed disc  42  generally lies within a plane of revolution P when in a non-deflected state, and is deflected laterally from the plane P by deflectors  48  during rotation within housing  36  ( FIG. 6 ). The extent to which seed disc  42  is deflected can vary dependent upon the particular seed meter configuration. In the seed pool area  38 A, seed disc  42  should “scoop” the seeds to ensure all seed cells  46  receive a seed; whereas in the region of outlet  38 B, seed disc  42  should be tipped over to an extent providing effective seed release. In the embodiment shown, seed disc  42  is deflected between approximately 2 to 45 degrees in each of seed pool area  38 A and outlet  38 B, more preferably approximately 5 to 20 degrees. The seeds are discharged from seed meter  32  to seed placement system  30  at a predetermined rate. Closing wheels  26  close the seed trench and thereby cover the seed in the trench. 
     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.