Hydraulic system for controlling a gang of lawn mowers

{
  "publication_number": "US3992858A",
  "country": "US",
  "kind": "A",
  "title": "Hydraulic system for controlling a gang of lawn mowers",
  "abstract": "A hydraulic system for controlling a gang of lawn mowers including a hydraulic pump and a multi-section valve and hydraulic motors driving the mowers. Hydraulic cylinders are also included in the system, for raising and lowering the mowers, and a check valve is connected with the cylinders for controlling the lowering of the mowers. The main valve is arranged with a plurality of spools which control the aforementioned functions and with the spools being set by means of a single handle so that the operator can perform the aforementioned functions through maneuvering the single handle for each set of hydraulic motors and cylinders. A hydraulic flow restrictor is included in the system for reversing the motors at a speed slower than the forward motor speed, for a slower reverse rotation of the mowers, such as for back-lapping of the mowers.",
  "claims": [
    "1. A hydraulic system for controlling a gang of lawn mowers, comprising a hydraulic pump, a single-bodid hydraulic valve having a plurality of sections with each of said sections having a separate hydraulic inlet hydraulically connected with said pump, each of said valve sections having a first and a second hydraulic flow outlet, a plurality of lawn mowers, a plurality of hydraulic motors respectively hydraulically connected with said first valve outlets and operatively associated with said mowers for driving said mowers, a plurality of hydraulic cylinders respectively hydraulically connected with said second valve outlets and operatively associated with said mowers for raising and lowering said mowers, a valve spool shiftably disposed in each of said sections and with each of said spools having two hydraulic flow passageways respectively alignable with the first and second said valve outlets for passing hydraulic fluid to said valve outlets, and a handle operatively connected with each of said spools for selective shifting of said spools and consequent passing of hydraulic fluid to either of the two said valve outlets, for either powering said mowers or raising and lowering said mowers.",
    "2. The hydraulic system for controlling a gang of lawn mowers as claimed in claim 1, wherein said valve has an additional single outlet in hydraulic flow communication with all of said sections for return of hydraulic fluid to said pump.",
    "3. The hydraulic system for controlling a gang of lawn mowers as claimed in claim 1, wherein there is a total number of five said motors, and the total number of said valve sections is two less than that of said motors, and including hydraulic connections extending between one of said sections and three of said motors.",
    "4. The hydraulic system for controlling a gang of lawn mowers as claimed in claim 1, wherein said hydraulic cylinders are single acting cylinders, and including a hydraulic check valve hydraulically connected with and between each said second valve outlet and the respective said hydraulic cylinder, for resisting return flow of fluid from said hydraulic cylinders and thereby control the lowering of said mowers.",
    "5. The hydraulic system for controlling a gang of lawn mowers as claimed in claim 4, wherein each of said valve sections has a third hydraulic flow outlet, and including a hydraulic pilot line hydraulically connected between said third hydraulic flow outlet and said check valve for opening said check valve by applying hydraulic pressure thereto.",
    "6. The hydraulic system for controlling a gang of lawn mowers as claimed in claim 5, including a poppet valve hydraulically connected in said pilot line and operatively associated with said check valve for holding said check valve in an open position.",
    "7. The hydraulic system for controlling a gang of lawn mowers as claimed in claim 1, wherein the total number of said motors and said mowers is at least five of each, and said pump is a single bodied unit having a number of pumping sections which are a total of two less than said total number of said motors.",
    "8. The hydraulic system for controlling a gang of lawn mowers as claimed in claim 1, including a hydraulic reversing valve hydraulically connected between and with said first valve outlets and said motors for reversing the direction of rotation of said mowers.",
    "9. The hydraulic system for controlling a gang of lawn mowers as claimed in claim 8, wherein said mowers are the conventional reel type with each including a rotatable grass cutting reel and a bed knife, and said motors being operatively associated with said reels for rotation of said reels in both directions of rotation and with one direction being a grass cutting direction and the other direction being a back-lapping of said reel over said bed knife for sharpening of said reel.",
    "10. The hydraulic system for controlling a gang of lawn mowers as claimed in claim 9, including a hydraulic restrictor hydraulically connected with said reversing valve for reducing hydraulic flow to said motors when said reversing valve is in its reverse mode, to thereby cause said reels to rotate slower in the back-lapping direction compared to the grass cutting direction.",
    "11. The hydraulic system for controlling a gang of lawn mowers as claimed in claim 8, including an electrically operative system operatively associated with said reversing valve for controlling the latter, and said electrically operative system including a battery and an electric switch for energizing said electrically operative system.",
    "12. The hyraulic system for controlling a gang of lawn mowers as claimed in claim 11, wherein said electrically operative system includes an electric solenoid and a hydraulic valve for controlling said reversing valve.",
    "13. The hydraulic system for controlling a gang of lawn mowers as claimed in claim 12, including an electric indicator lamp electrically connected with said switch for indicating when said electrically operative system is being energized.",
    "14. The hydraulic system for controlling a gang of lawn mowers as claimed in claim 1, including a pressure relief valve hydraulically connected with each of said second valve outlets for limiting hydraulic flow to said cylinders, and including a hydraulic return line hydraulically connected between said relief valve and said pump for return flow to said pump.",
    "15. The hydraulic system for controlling a gang of lawn mowers as claimed in claim 14, including a poppet valve and a check valve with both hydraulically connected between said pressure relief valve and said cylinder and arranged to be responsive to the hydraulic pressure at said relief valve for hydraulically opening said poppet valve, and said poppet valve having means for holding itself in the open position independent of hydraulic pressure thereat.",
    "16. The hydraulic system for controlling a gang of lawn mowers as claimed in claim 1, wherein there is one said motor for each said mower and the total number of said motors and said mowers is an uneven number of at least three of each, and said pump is a single bodied unit having a total number of pumping sections which is two less than said total number of said motors."
  ],
  "description_excerpt": "This invention relates to a hydraulic system for controlling a gang of lawn mowers, and, more particularly, it relates to and includes a hydraulic system having a hydraulic pump and a valve and a plurality of lawn mowers which are under the influence of the hydraulic system for both the powering of the mowers in grass cutting and raising and lowering of the mowers.\n\nThe prior art is already aware of various hydraulic systems which are utilized for powering lawn mowers, and for raising and lowering the mowers under the influence of hydraulic pressure. That is, the prior art is aware of mowing machines which include a tractor unit whereon the mowers are supported for transport over the ground, and the tractor includes a prime mover and a hydraulic system for powering the mowers in the cutting action and in raising and lowering the mowers. Examples of the prior art are found in U.S. Pat. Nos. 3,511,034 and 3,563,011 and in U.S. patent application Ser. No. 506,261 filed Sept. 16, 1974, and now U.S. Pat. No. 3,918,240.\n\nThe prior arrangements of gang mowing machines, such as those cited above, normally require a complexity of a hydraulic system wherein one section of the system is utilized for controlling the rotation or powering of the grass cutter itself, and another section of the system is utilized for raising and lowering the mowers relative to the supporting tractor. That is, the prior art requires that there be two branches of a hydraulic system and that there be separate control handles and the like for each of the two branches.",
  "cpc": [
    "F15B 11/17",
    "A01D 34/60",
    "A01D 75/30",
    "F15B 2211/20538",
    "F15B 2211/20576",
    "F15B 2211/30585",
    "F15B 2211/30595",
    "F15B 2211/67",
    "F15B 2211/7121",
    "F15B 2211/7142"
  ],
  "ipc": [
    "A01D 75/30",
    "F15B 11/17"
  ],
  "assignees": [
    "Jacobsen Manufacturing Co"
  ],
  "inventors": [
    "Glenn Richard Hubbard",
    "Harold John Jacoby",
    "Frank Allen Ecker",
    "Donald Gene Haffner",
    "Anthony Joseph Saiia"
  ],
  "filing_date": "1975-12-01",
  "publication_date": "1976-11-23",
  "grant_date": "1976-11-23",
  "priority_date": "1975-12-01",
  "application_number": "US-63669775-A",
  "family_id": "24552976",
  "cited_by_count": 42,
  "citations": [
    "US3563011A",
    "US3918240A"
  ]
}