Articulated tractor vehicle power steering and brake system having an emergency brake device

{
  "publication_number": "US3802746A",
  "country": "US",
  "kind": "A",
  "title": "Articulated tractor vehicle power steering and brake system having an emergency brake device",
  "abstract": "A power steering and brake system for a vehicle, especially an off-highway articulated vehicle, having a brake actuating accumulator by diverting a small amount of fluid flow from a steering circuit. A self acting emergency brake is activated upon loss of accumulator pressure below a level satisfactory for operating the service brakes. The emergency brake may also be selectively operated as a parking brake when the vehicle is halted by dumping pressure from the accumulator.",
  "claims": [
    "1. In an off-highway tractor vehicle having articulated sections pivoted about a vertical turning axis, steering jacks connected between said sections for turning one relative to the other about said axis, an engine on one section, a drive train on said section connected to wheels on opposite sides driven by the engine through said drive train, spring disengageable and fluid pressure applyable service brakes for said wheels, support wheels on said other section having spring disengageable and fluid pressure applyable service brakes, the improvement comprising a power brake and steering system including a fluid reservoir, a pump driven by the engine connected to the reservoir, a main brake valve, a steering valve selectively operable for controlling said steering cylinders to effect turning movement of the vehicle sections receiving fluid under pressure from the main brake valve and returning exhaust fluid from the steering cylinders to the reservoir, an accumulator connected to the pump through said main brake valve, an auxiliary brake valve connected to the accumulator, emergency brake means having fluid pressure disengageable-spring applyable brake heads receiving fluid pressure through said auxiliary brake valve from the accumulator, return conduit means from the auxiliary brake valve to said reservoir and means selectively operable controlling said auxiliary brake valve to interrupt fluid pressure from the accumulator to the emergency brake means and connect said return conduit means thereto for rapidly exhausting fluid to the reservoir permitting said emergency brake means to be spring applied.",
    "2. The improvement according to claim 1 wherein said drive train includes a rotatable drive element and said emergency brake means being associated with said rotatable drive element.",
    "3. The imprOvement according to claim 2 wherein said rotatable drive element is the tractor differential input shaft and said pressure disengageable-spring appliable brake heads, positioned closely adjacent to said shaft, being yieldably engageable therewith when said fluid pressure is exhausted."
  ],
  "cpc": [
    "B60T 13/141",
    "B60T 13/22",
    "B62D 5/07"
  ],
  "ipc": [
    "B60T 13/14",
    "B60T 13/18",
    "B60T 13/22",
    "B62D 5/07"
  ],
  "assignees": [
    "Clark Equipment Co"
  ],
  "inventors": [
    "M Walser"
  ],
  "filing_date": "1972-08-23",
  "publication_date": "1974-04-09",
  "grant_date": "1974-04-09",
  "priority_date": "1972-08-23",
  "application_number": "US-28302072-A",
  "family_id": "23084143",
  "cited_by_count": 32,
  "citations": [
    "US3463276A",
    "US3695731A",
    "US3547233A",
    "US3528707A",
    "US3599761A"
  ]
}