Planter meter suspension system and method of improving seed spacing

1. A system to reduce vertical acceleration experienced by seed meters of an agricultural planter during planting operations, said system comprising:

in an agricultural planter having a plurality of spaced row units, each row unit mounted to a transverse toolbar of the planter main frame independently vertically movable relative to said transverse toolbar, each row unit having a lower bracket operably supporting a furrow opening assembly and a rearwardly extending upper support member disposed above said lower bracket and operably supporting a seed meter;

a suspension system for each of said row units, said suspension system disposed to operably vertically support said upper support member vertically movable independently of said lower bracket of each of said row units;

whereby each of said spaced row units is vertically independently movable relative to said transverse toolbar and each of said upper support members is vertically independently movable relative to said lower brackets of each of said spaced row units.

2. The system of claim 1 wherein said suspension system includes a slide system and a spring system.

3. The system of claim 2 wherein said slide system comprises a substantially vertically disposed rod supported by said lower bracket of said row unit frame;

at least one linear bearing slidably disposed on said vertically disposed rod, said at least one linear bearing operably mounted to a forward end of said upper support member.

4. The system of claim 2 wherein said spring system includes:

an air spring operably mounted to said lower bracket and to said upper support member;

an air reservoir in fluid communication with said air spring and a pressurized air source;

a valve to regulate air in said spring system;

a cam supported by said slide system mounted to said row unit frame;

a cam follower lever that contacts said cam, said cam follower lever supported by said upper support member;

a port on said valve for venting air in said spring system to atmosphere.

5. The system of claim 4 further including a dampener, said dampener comprising an orifice disposed in the spring system between said air spring and said reservoir to reduce air flow between said spring and said reservoir.

6. The system of claim 2 wherein said spring system includes:

an air spring disposed between said row unit frame and said upper support member;

an air source in fluid communication with said air spring; and

a valve system to regulate air in said air spring.

7. The system of claim 6 further including a dampener, said dampener comprising an orifice disposed between said air spring and said air source to reduce air flow between said spring and said air source.

8. The system of claim 1 wherein said suspension system includes a parallel linkage.

9. The system of claim 8 wherein said suspension system further includes a spring system, said spring system comprising:

an air spring disposed between said lower bracket and said upper support member;

an air source in fluid communication with said air spring; and

a valve system to regulate air in said air spring.

10. The system of claim 9 further including a dampener, said dampener comprising an orifice disposed between said air spring and said air source to reduce air flow between said spring and said air source.

11. A planter, comprising:

a mobile main frame having a transverse toolbar;

a plurality of row units operably supported at spaced intervals along said transverse toolbar, each row unit having a row unit frame comprising an upper support member operably supporting a seed meter and a lower bracket operably supporting a furrow opening assembly, said lower bracket disposed below said upper support member; and

a suspension system disposed to isolate said upper support member from said lower bracket to reduce vertical motion experienced by said row unit frame during planting operations as the planter traverses a ground surface.

12. The planter of claim 11 wherein said suspension system includes:

a substantially vertically disposed rod operably supported by said lower bracket; and

at least one linear bearing slidably disposed on said substantially vertically disposed rod, said at least one linear bearing operably mounted to a forward end of said upper support member.

13. The planter of claim 12 wherein said suspension system further includes:

an air spring disposed between said lower bracket and said upper support member;

an air source in fluid communication with said air spring; and

a valve system to regulate air in said air spring.

14. The planter of claim 13 further including a dampener, said dampener comprising an orifice disposed between said air spring and said air source to reduce air flow between said spring and said air source.

15. The planter of claim 11 wherein said suspension system includes a parallel linkage.

16. The planter of claim 15 wherein said suspension system further includes a spring system, said spring system comprising:

an air spring disposed between said lower bracket and said upper support member;

an air source in fluid communication with said air spring; and

a valve system to regulate air in said air spring.

17. The planter of claim 16 further including a dampener, said dampener comprising an orifice disposed between said air spring and said air source to reduce air flow between said spring and said air source.