Caterpillar Inc.

Caterpillar Sarl

Shin Caterpillar Mitsubishi Ltd.

S.a.r.l.

Steven T Ufheil

Raymond T Schenck

Stephen W Rector

John James Krone

David P Smith

Eric Alan Reiners

Reid W Waitt

Stephen J Morey

Dennis J Hausman

W Chris Swick

Randy R Hayward

Rick D Vance

Robert D Carlson

Roy V Brookhart

Stephen P Amborski

Laurence M Rubin

Timothy W Grunow

A hydraulic system, particularly suitable for use in a work machine, is provided with a hydraulic pressure source. A first hydraulic load is associated with a first load function. A second hydraulic load is associated with a second load function. An independent metering valve assembly includes a plurality of independently and electronically controllable valves. The independent metering valve assembly includes an inlet fluidly coupled with the pressure source, a first outlet fluidly coupled with the first hydraulic load, and a second outlet fluidly coupled with the second hydraulic load. The hydraulic system is configured such that the independent metering valve assembly may operate and drive multiple hydraulic load functions.

Independent metering valve assembly for multiple hydraulic load functions

A tool recognition and control system for electronically configuring certain systems of a work machine based upon the operating parameters associated with a particular work tool to be attached thereto, the work machine including systems operable to control the operation of a plurality of different work tools, each work tool having a set of operating parameters associated therewith which affect the operation of at least some of the systems of the work machine, the present control system identifying the particular work tool attached to the work machine based upon either a signal generated by a tool recognition system associated with the work tool when the work tool is attached to the work machine, or based upon operator selectable commands for selecting any one of a plurality of different sets of operating parameters based upon the particular work tool attached to the machine. Once the work tool has been identified and the appropriate set of operating parameters selected, an electronic controller coupled to the various systems of the work machine operable to control the operation of the various work tools outputs appropriate signals to such systems for electronically configuring such systems in accordance with the selected set of operating parameters for a particular work tool. Once configured, the affected systems will be compatible with the selected operating parameters for that particular work tool.

Tool recognition and control system for a work machine

A control system and method for detecting and inhibiting an impending full saturation condition in a hydraulic system of a work machine wherein the hydraulic system includes a hydraulic pump for supplying fluid under pressure to the hydraulic system and a plurality of control valves for controllably passing fluid from the pump to a plurality of work elements, the present control system including an electronic controller coupled to both an operator input device actuatable to control the operation of the work elements and a plurality of control valves for controlling the fluid flow to the work elements, the controller being operable to determine the actual margin pressure of the hydraulic pump in response to comparing the pump pressure to the pressure of the heaviest loaded work element requested by an operator through the actuation of the operator input device and to compare the actual margin pressure to the established margin pressure for the pump. Based upon this comparison, the controller is further operable to output appropriate signals to the control valves to limit fluid flow thereto in accordance with some type of valve prioritization scheme when the actual margin pressure of the pump is less than the established margin pressure. The present control system and method functions as an early warning system to both detect the onset of an impending full saturation condition and to implement appropriate procedures to inhibit further saturation and limit any resultant valve starvation.

System and method for inhibiting saturation of a hydraulic valve assembly

An operational state sensor for controlling certain operations of a work machine such as a skid steer loader based upon the fulfillment of certain operator conditions, the operational state sensor including a first switch coupled to an operator restraint mechanism and actuatable between a first mode of operation corresponding to the condition when the operator restraint mechanism is in a non-restraining condition and a second mode of operation corresponding to the condition when the operator restraint mechanism is in a restraining condition, a second switch coupled to the operator seat and actuatable between a first mode of operation corresponding to the condition when an operator is not present in the seat and a second mode of operation corresponding to the condition when an operator is present in the seat, and an electronic controller coupled to the first and second switches for receiving signals therefrom, the controller being operable to receive a first signal indicative of when the first switch is either in or out of its first mode of operation and a second signal indicative of when the first and second switches are either concurrently in their second modes of operation or at least one of such switches is out of its second mode of operation, the controller being further operable to control the certain operations of the work machine based upon said first and second signals.

Arm rest/seat switch circuit configuration for use as an operational state sensor for a work machine

A method and apparatus for controllably engaging, or disengaging, or both engaging and disengaging, a neutralize mode associated with a transmission located on a machine is disclosed. The machine has a controller, a memory associated with the controller, and a braking system. A determined system brake pressure is compared with at least one of an established neutralize pressure value and in gear pressure value. The neutralize mode is engaged or disengaged in response to the comparison.

Method and apparatus for controlling a transmission associated with a neutralize mode

A steering control system for controlling the steering of a work machine which utilizes differential speed control for maneuvering the machine wherein the operator of the work machine can select any one of a plurality of different steering modes which vary the gain of the operator input steering device based upon operating or environmental conditions, or based upon other sensed conditions of the work machine such as the ground speed of the machine. The present steering control system includes an operator input device actuatable to command a particular direction of movement of the work machine, a steering mode switch or other operator selectable mechanism for selecting any one of a plurality of different steering mode correlations established between actuation of the operator input device and operation of the respective left and right drive motors associated with the work machine, each steering mode correlation representing a different mode of operation of the left and right drive motors for the same input to the operator input device, and an electronic controller coupled with the operator input device and with the steering mode switch or other mechanism for receiving signals therefrom and for outputting signals to control the operation of the left and right drive motors in accordance with the selected steering mode.

Variable gain steering control system for a work machine

An interlock control system for controlling certain operations of a work machine wherein such system includes a first switch coupled to an operator restraint mechanism, a second switch coupled to the operator seat, a third switch operable to control the operation of the parking brake mechanism, and an electronic controller coupled to all three switches for receiving signals therefrom, the controller outputting a signal to enable the drive mechanism and the implement control system when the controller receives signals from the first, second and third switches indicative of the fact that the operator is present in the seat, the operator restraint mechanism is positioned in its restraining position, and the parking brake switch has been actuated to release the parking brake. With the drive mechanism and implement control system enabled, a second activation of the parking brake switch will disable the drive mechanism and set the parking brake, but it will not disable the implement control system. In addition, regardless of the particular operating mode, as soon as the interlock controller senses that either the operator restraint mechanism has been moved out of its restraining position and/or the operator is no longer present in the seat, the controller will disable the drive mechanism and the implement control system, and it will apply the parking brake.

Interlock control system for a work machine

An auxiliary hydraulic control system for controlling the flow of hydraulic fluid within an auxiliary hydraulic circuit associated with a particular work machine wherein such system includes a first bi-directional proportional switch actuatable to control the direction of flow within the auxiliary hydraulic circuit in either a first or a second direction and at a flow rate which is proportional to the amount of pressure being exerted on the switch in the selected direction, a second switch actuatable to provide continuous flow in the selected direction and at the selected flow rate, and an electronic controller coupled to the first and second switches for receiving signals therefrom, the controller outputting a signal to initiate continuous flow in the selected direction and at the selected flow rate when the controller receives signals indicative of the first switch being actuated, the second switch being actuated, and the first switch being released within a predetermined period of time after the second switch has been actuated. An interlock override feature is also provided whereby, under certain operating conditions, the continuous flow function will be allowed to remain active while an operator exits the machine seat.

Auxiliary hydraulic control system for a work machine

The present invention provides a ride control 100 for a machine having an implement and a hydraulic lift cylinder. The hydraulic lift cylinder is adapted for moving the implement to and between a plurality of positions. The ride control is controllable between a RIDE CONTROL ON mode, a RIDE CONTROL OFF mode and a RIDE CONTROL PROGRAM mode. In the RIDE CONTROL ON mode, the ride control connects and disconnects an accumulator from the hydraulic lift cylinder circuit as a function of machine velocity. In the RIDE CONTROL OFF mode, the ride control disconnects the accumulator from the hydraulic lift cylinder circuit. In the RIDE CONTROL PROGRAM mode, the ride control sets the threshold for activation of the ride control to the current machine velocity.

Programmable ride control

An apparatus is provided for use in a vehicle having an engine driven transmission which includes a plurality of gear ratios. The apparatus includes a sensor adapted to sense an operating parameter and responsively produce a parameter signal. A memory device includes a custom shiftpoint map for storing data which relates transmission gear ratio to the parameter signal. A programming device for allowing the custom shiftpoint map to be reprogrammed during vehicle operation. A controller is adapted to receive the vehicle speed signal, retrieve data from the custom shiftpoint map, and process the retrieved data and the parameter signal to produce a transmission control signal. An actuator is adapted to receive the transmission control signal and responsively control the transmission gear ratio.

Automatic transmission with programmable shiftpoints

An apparatus and method for controlling a variable displacement motor of a hydrostatic transmission is provided. The apparatus includes an engine, and a hydraulic pump mechanically coupled to the engine. The variable hydraulic motor includes an output shaft. The apparatus monitors rotational speed of the output shaft. The apparatus and method control motor displacement and detect and/or predict the occurrence of an overspeed condition. The displacement of the motor is modified if an overspeed condition is predicted and/or detected.

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East Peoria, IL, United States of America

Steven T Ufheil