×

Down pressure control mechanism for grain drills

  • US 4,077,478 A
  • Filed: 02/22/1977
  • Issued: 03/07/1978
  • Est. Priority Date: 02/22/1977
  • Status: Expired due to Term
First Claim
Patent Images

1. A furrow opener assembly for a grain drill or the like having a main frame, a subframe movably mounted to said main frame and including a furrow opener member, said mounting of said subframe permitting movement of said furrow opener to a working position with the furrow opener member in the ground and upwardly therefrom, and means to resiliently resist upward movement of said furrow opener member and said subframe comprising a linkage means operably connected between said main frame and said subframe, spring means connected to said linkage means, means guiding said linkage means in a desired path of movement as said subframe moves upwardly, said means guiding include a first working position guide section and a second guide section, said spring means resisting upward movement of the subframe through said linkage means at a first rate when the linkage means is guided in the working position guide section, and at a second substantially lower rate for each increment of upward movement of the subframe when the linkage means is guided in the second guide section after upward movement of said subframe from its working position.

View all claims
  • 0 Assignments
Timeline View
Assignment View
    ×
    ×