Hydraulic system and method of operating same
First Claim
Patent Images
1. A method of activating hydraulic cylinders on a waste collection vehicle comprising, in combination,a) pressurizing hydraulic fluid using a positive displacement pump;
- b) activating an operator control in communication with a closed center control valve having spools controlling open and closed positions of multiple ports in a first setting of open and closed positions;
c) repositioning the spools and changing the open and closed positions of the ports to a second setting using a control fluid and in response to activating the operator control;
d) redirecting the pressurized hydraulic fluid flow in response to the changing port settings of the closed center valve;
e) directing the pressurized hydraulic fluid using the control valve to at least one hydraulic cylinder; and
f) sensing a load applied to the hydraulic cylinder and adjusting the pressure applied to the hydraulic fluid by increasing or decreasing the flow from the positive displacement pump.
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Abstract
An improved hydraulic system and method of operating same for waste collection vehicles is provided where a closed center valve in conjunction with a positive displacement pump is used without the need for increasing engine RPM, thus significantly reducing vehicle noise during operation of the hydraulic system.
24 Citations
11 Claims
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1. A method of activating hydraulic cylinders on a waste collection vehicle comprising, in combination,
a) pressurizing hydraulic fluid using a positive displacement pump; -
b) activating an operator control in communication with a closed center control valve having spools controlling open and closed positions of multiple ports in a first setting of open and closed positions;
c) repositioning the spools and changing the open and closed positions of the ports to a second setting using a control fluid and in response to activating the operator control;
d) redirecting the pressurized hydraulic fluid flow in response to the changing port settings of the closed center valve;
e) directing the pressurized hydraulic fluid using the control valve to at least one hydraulic cylinder; and
f) sensing a load applied to the hydraulic cylinder and adjusting the pressure applied to the hydraulic fluid by increasing or decreasing the flow from the positive displacement pump. - View Dependent Claims (2, 3)
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4. A hydraulic system for a waste collection vehicle comprising, in combination,
a) a movable operator control having at least a first and second position; -
b) a closed center control valve in communication with the operator control;
c) a positive displacement pump in fluid communication with the close center valve;
d) at least one hydraulic cylinder operable in response to movement of the operator control and in response to a change in flow direction of hydraulic fluid caused by changing port positions in the closed center valve; and
e) a load sensor in communication with the positive displacement pump and capable of sensing a load applied to the hydraulic cylinder. - View Dependent Claims (5)
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6. A method of cycling and emptying a refuse container using a front-end loader waste collection vehicle comprising, in combination,
a) activating an operator control in communication with a closed center valve; -
b) directing pressurized hydraulic fluid using the closed center valve to at least one first hydraulic cylinder connected to at least one arm of a front-end loader vehicle;
c) raising the arm and refuse container in a continuous upward motion;
d) triggering a position sensor as the arm rises to a first predetermined position;
e) directing pressurized hydraulic fluid, using a combination of the closed center valve and a valve, to at least one second hydraulic cylinder connected to an articulating member attached to the arm and attached to the refuse container in response to the triggering of the position sensor;
f) continuously rotating the articulating member and the refuse container while continuously raising the arm and the refuse container up and above the refuse vehicle; and
g) emptying the refuse container into a hopper located on the refuse vehicle. - View Dependent Claims (7, 8)
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9. A method of cycling and emptying a refuse container using a front-end loader refuse vehicle comprising, in combination,
a) moving an operator control in communication with a control valve in a first direction; -
b) directing pressurized hydraulic fluid using the control valve to at least one first hydraulic cylinder connected to at least arm of a front end loader vehicle;
c) raising the arm and refuse container in a continuous upward motion;
d) triggering a first position sensor as the arm rises past a first predetermined position;
e) changing hydraulic fluid pressure in communication with at least one second hydraulic cylinder connected to an articulating member attached to the arms using the control valve in response to the triggering of the first position sensor, the articulating member being attached to the refuse container;
f) continuously rotating the articulating member and the refuse container while continuously raising the arms and the refuse container up and above the refuse vehicle;
g) emptying the refuse container into a hopper located on the refuse vehicle;
h) moving the operator control in a second direction;
i) directing pressurized fluid to at least one second hydraulic cylinder causing the articulating member and refuse container to continuously rotate up and away from the hopper;
j) triggering a second position sensor as the articulating member rotates past a second predetermined position;
k) continuously lowering the arm and the refuse container in response to the triggering of the second position sensor while continuously rotating the refuse can to a loading position. - View Dependent Claims (10)
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11. A system for cycling and emptying a refuse container using a front-end loader refuse vehicle comprising, in combination,
a) an operator control in communication with a closed center control valve, the operator control being capable of movement in a first and second direction; -
b) at least one first hydraulic cylinder in communication with the closed center valve and connected to at least one arm attached to the refuse vehicle;
c) at least one second hydraulic cylinder in communication with the closed center valve and connected to an articulating member attached to the refuse vehicle and attached to the refuse container;
d) a positive displacement pump in communication with the close center valve through the use of pressurized hydraulic fluid; and
e) at least one position sensor connected to a first valve in communication with the closed center valve responsible for activating the first hydraulic cylinder; and
f) at least one position sensor connected to a second valve in communication with the closed center valve responsible for activating the second hydraulic cylinder.
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Specification