Caterpillar Inc.

Catepillar Inc.

Robert E Stone

John Thomas Reedy

Steven Conrad Budde

Aaron Robert Shatters

Cynthia M Gardner

Steven A Daniel

Norval P Thomson

Daniel Peter Sergison

William E Allen

Corwin Eugene Storer

Hans P Dietz

Ricky D Vance

Michael Angel Cobo

Douglas James Carlton

James E Schimpf

John D Duffy

Todd M Weier

A hydraulic system for a mobile machine is disclosed. The hydraulic system may have a first actuator, a first valve arrangement, a second actuator, and a second valve arrangement. The hydraulic system may also have at least one operator interface device movable by an operator to generate a first signal indicative of desired work tool movement in a first manner, and a second signal indicative of desired work tool movement in a second manner; and a controller configured to generate a first flow rate command directed to the first valve arrangement based on the first signal, and generate a second flow rate command directed to the second valve arrangement based on the second signal. The controller may also be configured to selectively generate a third flow rate scaled from the first flow rate command and directed to the second valve arrangement based on only the first signal.

Hydraulic system having fixable multi-actuator relationship

A hydraulic system is disclosed. The hydraulic system may have a pump, a lift actuator, a lift valve arrangement, a tilt actuator, a tilt valve arrangement, and a tilt angle sensor configured to generate a first signal. The hydraulic system may further have at least one operator interface device movable to generate a second signal indicative of a desired lift velocity and a third signal indicative of desired tilt velocity, and a controller. The controller may be configured to command the lift valve arrangement to meter pressurized fluid based on the second signal, command the tilt valve arrangement to meter pressurized fluid based on the third signal and, when the first signal indicates that the actual tilt angle has entered a specified range of tilt angles during lifting, command the tilt valve arrangement to meter pressurized fluid based on the second signal as the actual tilt angle remains within the specified range.

System implementing parallel lift for range of angles

A hydraulic system for lifting a work tool of a mobile machine is disclosed. The hydraulic system may have a pump, a lift actuator, a lift valve arrangement, and a lift sensor configured to generate a first signal indicative of an actual lift velocity. The hydraulic system may also have a tilt actuator, a tilt valve arrangement, and at least one operator interface device movable to generate a second signal indicative of a desired lift velocity and a third signal indicative of desired tilt velocity. The hydraulic system may further have a controller configured to command the lift valve arrangement to meter pressurized based on the second signal, command the tilt valve arrangement to meter pressurized fluid based on the third signal, and command the tilt valve arrangement to meter pressurized fluid and maintain a desired tilt angle of the work tool during lifting based selectively on the first and second signals.

Lift system implementing velocity-based feedforward control

A wheel tractor scraper having a rear wheel drive assist, the wheel tractor scraper includes a tractor portion pivotally coupled to a rear scraper portion, the rear scraper portion having a bowl for hauling material and a fluid powered work tool configured to assist in loading the bowl, the work tool powered by a fluid pump connected to a fluid operated work tool motor. The rear wheel drive assist includes a fluid operated drive motor coupled to the rear wheels of the machine, a diverter valve having a first position at which fluid flow is delivered from the pump to the work tool motor and a second position at which fluid flow is delivered from the pump to the drive motor, and a controller being configured to control the diverter valve to engage the rear wheel drive assist. The machine may be operated by engaging the pump and work tool motor, and then actuating the diverter valve to the second position to divert flow from the work tool motor to the drive motor.

Wheel tractor scraper rear wheel drive assist and method of operation

An apparatus for limiting the control of a work implement is disclosed. The implement is connected to a work machine and is moveable in response to operation of a hydraulic cylinder. The apparatus includes an operator controlled joystick. A joystick position sensor senses the position of the joystick and responsively generates an operator command signal. An implement position sensor senses the position of the work implement and responsively produces an implement position signal. A microprocessor based controller receives the implement position and operator command signals, modifies the operator command signal, and produces an electrical valve signal in response to the modified operator command signal. An electrohydraulic valve receives the electrical valve signal, and controllably provides hydraulic fluid flow to the hydraulic cylinder in response to a magnitude of the electrical valve signal.

Method and apparatus for limiting the control of an implement of a work

An apparatus for controllably moving a work implement is disclosed. The implement is connected to a work machine and is moveable in response to operation of a hydraulic cylinder. The apparatus includes an operator controlled joystick. A joystick position sensor senses the position of the joystick and responsively generates an operator command signal. Boom and bucket angle sensors sense the position of the work implement and responsively produces an boom angle signal and a bucket angle signal respectively. A microprocessor based controller receives the boom angle, bucket angle, and operator command signals, modifies the operator command signal, and produces an electrical valve signal in response to the modified operator command signal. An electrohydraulic valve receives the electrical valve signal, and controllably provides hydraulic fluid flow to the hydraulic cylinder in response to a magnitude of the electrical valve signal.

Method and apparatus for controlling an implement of a work machine

An apparatus for controllably moving a work implement is disclosed. The implement is connected to a work machine and is moveable in response to operation of a hydraulic cylinder. The apparatus includes an operator controlled joystick. A joystick position sensor senses the position of the joystick and responsively generates an operator command signal. An implement position sensor senses the position of the work implement and responsively produces an implement position signal. A microprocessor based controller receives the implement position and operator command signals, modifies the operator command signal, and produces an electrical valve signal in response to the modified operator command signal. An electrohydraulic valve receives the electrical valve signal, and controllably provides hydraulic fluid flow to the hydraulic cylinder in response to a magnitude of the electrical valve signal.

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Metamora, IL, United States of America

Robert E Stone