Ballast attachment for tractor three-point hitch

{
  "publication_number": "US6533319B1",
  "country": "US",
  "kind": "B1",
  "title": "Ballast attachment for tractor three-point hitch",
  "abstract": "A ballast attachment for a tractor three-point hitch includes a cubical, rotational molded polyethylene shell filled with steel reinforced concrete. The front side of the attachment includes a forwardly opening receptacle for receiving a transverse hitch bar carried by the lower links of a tractor three-point hitch, the rear portion of the receptacle including a semi-cylindrical seat for the hitch bar. The center of gravity of the attachment causes the lower part of the attachment to tend to pivot about the hitch bar toward the tractor to the point where it engages the lower three-point hitch draft links. A chain secures the attachment in place.",
  "claims": [
    "1. In a ballast attachment adapted for being attached to a three point hitch and having opposite transversely spaced sides joined to front, rear and bottom sides, the improvement comprising: said ballast attachment including a hitch bar receptacle opening at and extending entirely across said front side of said ballast attachment, said receptacle including, and an upper rear location thereof, a downwardly facing horizontal seat adapted for receiving a hitch bar extending between lower draft links of said three-point hitch, said ballast attachment including spaced apart upper and lower forward parts, with a lower surface of said upper forward part defining an upper surface of said receptacle and with an upper surface of said lower forward part defining a lower surface of said receptacle; and said lower forward part being provided with a drawbar clearance slot located centrally between opposite sides of said lower forward part and extending a full height dimension of said lower forward part.",
    "2. The ballast attachment defined in claim 1 wherein said upper forward part is offset rearwardly relative to said lower forward part.",
    "3. The ballast attachment defined in claim 2 wherein said upper surface of said lower forward part is inclined upwardly and rearwardly from a front surface of said lower forward part to a location below said horizontal seat; and said lower surface of said upper forward part, and then upwardly to said horizontal seat.",
    "4. The ballast attachment defined in claim 2 wherein said upper and lower forward parts respectively include upper and lower vertical front wall sections.",
    "5. The ballast attachment defined in claim 1 wherein said transverse horizontal seat is so located relative to a center of gravity of said ballast attachment that said ballast attachment, when lifted from a horizontal surface by a transverse hitch bar located in said seat and carried by lower draft links of said three-point hitch, will tend to pivot about said bar such that said lower portion moves toward a tractor carrying said three-point hitch.",
    "6. In a combination of a three-point hitch including a pair of lower draft links having a cylindrical hitch bar extending between respective locations near rear ends of the draft links, and a ballast attachment secured to said links, the improvement comprising: said ballast attachment having a width just slightly less than the distance between rear end locations of said draft links and being a substantially cubical one-piece structure having top, bottom, right-hand, left-hand, front and rear sides; said front side being provided with a forwardly opening hitch bar receptacle extending rearwardly from and entirely across said front side and terminating at a downwardly facing seat elevated from the remainder of said receptacle and being shaped complementary to and receiving said hitch bar.",
    "7. The combination defined in claim 6 wherein a pair of centering guides are respectively fixed to spaced apart locations of said hitch bar adjacent inner sides of said draft links, said guides having respective surfaces shaped for guiding said draft links for passing on opposite sides of said ballast attachment during placement of said hitch bar into said seat.",
    "8. The combination defined in claim 6 wherein said receptacle as a lower surface which is inclined upwardly from front to rear and terminates at a location vertically below said seat.",
    "9. The combination defined in claim 6 wherein said tractor includes a drawbar located below and centered relative to said draft links; and said ballast attachment having a centrally located, fore-and-aft extending clearance notch provided in a central lower location thereof for permitting passage of said drawbar when the ballast attachment is raised and lowered relative to said drawbar by raising and lowering said draft links.",
    "10. The combination defined in claim 6 wherein said seat is located forwardly of a center of gravity of said attachment so that the bottom of said attachment pivots about said hitch bar towards said tractor when the ballast attachment is raised from the ground by operation of said three-point hitch.",
    "11. The combination defined in claim 10 wherein said draft links include forward portions spaced closer together than said respective locations near rear ends of the draft links; said forward positions being positioned for being contacted by said ballast attachment when said ballast attachment has pivoted a predetermined amount about said hitch bar.",
    "12. The combination defined in claim 11 and further including a flexible element extending about said ballast attachment from one draft link to the other draft link so as to hold the ballast attachment in engagement with said draft links.",
    "13. The combination defined in claim 6 wherein said ballast attachment has an upper forward portion which is set back relative to a lower forward portion of said ballast attachment.",
    "14. The ballast attachment defined in claim 1 wherein said ballast attachment is encased in a plastic material.",
    "15. The ballast attachment defined in claim 6 wherein said ballast attachment is encased in a plastic material."
  ],
  "description_excerpt": "The present invention relates to tractor ballast and, more specifically, relates to ballast boxes for attachment to tractor three-point hitches.\n\nWith front-mounted implements, a loader, for example, attached to a tractor, instability of the tractor, especially the rear of the tractor, can result. Instability can include front-end and sideways tipping. Counterweights, known as ballast, must be applied to the rear of the tractor in order to prevent this instability.\n\nCurrently, fluid is injected into the rear tractor tires and/or cast iron wheel weights are bolted to the rims of the rear tractor tires to achieve initial ballast. This method of adding ballast is undesirable for lawn care implements. It is also known to add further ballast by mounting a detachable ballast box implement to the tractor rear three-point hitch. A known ballast box attachment is a 610 mm x 406 mm x 508 mm steel box, which users contend is difficult to move or attach or detach from the three-point hitch when filled with sand or cement, as is the practice. This box has the further drawback of protruding farther rearward and upward than is desired, thus decreasing the amount of stability provided to the tractor.\n\nAccording to the present invention, there is provided an improved ballast attachment for mounting to a tractor three-point hitch.\n\nAn object of the invention is to provide a three-point hitch ballast attachment which is easy to attach to, and detach from, the three-point hitch and which provides good stability.",
  "cpc": [
    "A01B 59/06",
    "B62D 49/0628",
    "B62D 49/085"
  ],
  "ipc": [
    "A01B 59/06",
    "B62D 49/06",
    "B62D 49/08"
  ],
  "assignees": [
    "Deere and Co"
  ],
  "inventors": [
    "Jeffrey Gary Denby",
    "Daniel Robert Fuzzen"
  ],
  "filing_date": "1998-12-23",
  "publication_date": "2003-03-18",
  "grant_date": "2003-03-18",
  "priority_date": "1998-12-23",
  "application_number": "US-22017098-A",
  "family_id": "22822367",
  "cited_by_count": 42,
  "citations": [
    "US3614135A",
    "US3888507A",
    "US4094534A",
    "US4537423A",
    "US4518305A",
    "US4659102A",
    "US5197552A",
    "US5690359A"
  ]
}