Variable relief circuit
AssigneeHUSCO International, Inc.
InventorLevi Nauman
Life of this patent
Estimating the term…
Abstract
A relief circuit is operable between a first state and a second state to allow different functions of a hydraulic system to relieve at different pressures. In the first state of the relief circuit, the relief circuit is configured so that each of the functions of the hydraulic system relieve at the same pressure. In the second state of the relief circuit, the relief circuit is configured so different functions of the hydraulic system can operate simultaneously while also relieving at different pressures. In particular, a first function relieves at a first pressure and a second function relieves at a second pressure that is higher than the first pressure.
Claims20
A relief circuit comprising:
- a main supply line including a first inlet and an outlet;
- a first relief valve connected to the main supply line, the first relief valve being configured to relieve at a first pressure;
- a second relief valve connected to the main supply line, the second relief valve being configured to relieve at a second pressure higher than the first pressure;
- and
- a second inlet provided between the first inlet and the first relief valve;
- wherein, in a first state, both the first inlet and the second inlet are fluidly coupled to the first relief valve so that a pressure at the first inlet and a pressure at the second inlet each relieve at the first pressure through the first relief valve;
- and
- wherein, in a second state, the first inlet is fluidly isolated from first relief valve so that the pressure at the first inlet relieves at the second pressure through the second relief valve and the pressure at the second inlet relieves at the first pressure through the first pressure relief valve.
A relief circuit comprising:
- a main supply line;
- a first inlet;
- a second inlet;
- a first relief valve configured to relieve at a first pressure;
- a second relief valve configured to relieve at a second pressure higher than the first pressure;
- and
- a first control valve operable in a first mode and a second mode;
- wherein, in the first mode, the first control valve operates to fluidly couple the first inlet to the first relief valve;
- wherein, in the second mode, the first control valve operates to isolate the first inlet from the first relief valve;
- wherein the second inlet is fluidly coupled to the first relief valve during operation of the first control valve in both the first mode and the second mode;
- and
- wherein, the first inlet is coupled to the second relief valve during the first and second mode.
A hydraulic system, comprising:
- a load sense conduit including an inlet and an outlet;
- a first relief leg coupled to the load sense conduit, the first relief leg including a first relief valve configured to open at a first relief pressure, and a first control valve coupled between the first relief valve and the load sense conduit;
- a second relief leg coupled to the load sense conduit, the second relief leg including a second relief valve configured to open at a second relief pressure that is greater than the first relief pressure;
- a first function coupled between the load sense conduit and the first control valve, the first function configured to operate at a first function pressure;
- and
- a second function coupled between the first control valve and the first relief valve, the second function configured to operate at a second function pressure,
- wherein, with the first control valve in a first position both the first function pressure and the second function pressure are limited to the first relief pressure, and
- wherein, with the first control valve in a second position the second function pressure is limited to the first relief pressure and the first function pressure is limited to the second relief pressure.
Dependencies are inferred from the claim text.