Clark Equipment Compnay

Ransomes America Corporation

Other

Doosan Bobcat North America Inc.

Christopher L Young

Jason Lee Magnuson

Spencer Lee Mindeman

Richard D Bednar

Joseph J Oliver

David A Geringer

Richard G Geringer

Ronald S Hansen

Brady J Bertsch

John Hoaby

Timothy J Alger

William E Haberman

Charles P Hoaby

John M Hoaby

Jason L Magnuson

Power machines having hydraulic systems and controllers configured to prohibit, limit, or allow full operation of the hydraulic systems based upon measured temperature of the hydraulic oil in the system are provided. Also included are methods of controlling the hydraulic systems. In the methods implemented by the controllers, determinations are made as to whether the temperature of the hydraulic oil is below a first (and lowest) set point temperature, above a second (and higher) set point temperature, or between the first and second set point temperatures. The controllers then either prohibit hydraulic system operation, allow limited hydraulic system operation, or allow full hydraulic system operation, based upon the measured temperature in comparison to the two or more set point temperatures.

Hydraulic drive control

Power machines, control systems and methods that adjust engine speed based upon actuation of user input controls that control other power machine functions such as travel functions and lift arm functions. By controlling engine speed at least partially in response to the user input devices controlling other machine functions, more optimal engine speeds can be achieved.

Variable engine speed control

A power machine having an engine that generates a torque output and a power conversion system configured to receive the torque output and provide a drive power signal in response to actuation signals for propelling the machine is disclosed. An engine controller provides an engine torque data signal indicative of a torque load on the engine. A user input device generates an input signal indicative of intention to propel the machine. An electronic controller is in communication with the user input device, the power conversion system, and the engine controller. The electronics controller receives the input signal and provides actuation signals to the power conversion system. The electronic controller further provides the actuation signals as a function of the engine torque data signal to limit the engine torque load.

Power management for a drive system

Disclosed embodiments include power machines that provide an electronic tag along mode of operation. A control system is coupled to and selectively provides power to the left and right side tractive elements from the power source. First and second user input devices each provide an actuation signal indicative of manipulation between a neutral state and a forward state. An electronic tag-along input device provides a tag-along activation signal. When each of the first and second user input devices are in the forward state and the electronic tag-along input device provides a tag-along activation signal, a controller maintains power to the left and right side tractive elements when one of the first and second user input devices is in the forward state and the other of the first and second user input devices is the forward or neutral state.

Electronic tag along

A method of altering a drive parameter of a machine having a drive system that is configured to operate a left side of the machine independently of the right side of the machine. The method includes entering, by a user, a drive parameter alteration mode by actuating a first input, and actuating a second input to alter one or more parameters associated with a controller of the machine.

Drive control system for a vehicle and method

Controlling a drive system for a power machine having an engine is discussed. The method includes receiving a control signal and calculating a base output value based on the control signal. The base output value is compensated for a load applied to the engine. A signal indicative of the compensated output value is provided to a drive component.

Engine load management for power machines

An improved pressure-actuated door access bar is disclosed which may be located on a door to control access or egress through the door, whereby the door access bar is used to trigger unlocking or opening, or both unlocking and opening, of the door following pressure being exerted on the door access bar by an individual desiring access or egress through the door. Two electromechanical force transducer assemblies having no moving parts are mounted within a rigid base member which may in turn be mounted on a door or in another desired location, and a cover member mounted over the base member exerts pressure on the electromechanical force transducer assemblies when pressure is placed on it. When a given amount of pressure is detected by either or both of the electromechanical force transducer assemblies, the door will be unlocked or opened, or both unlocked and opened. A redundant emergency switch is also located in the door access bar of the present invention, and will operate in a fail-safe manner to unlock the door in the event of a failure of one or both of the electromechanical force transducer assemblies upon detection of a greater amount of force being exerted upon the cover member.

Push bar with redundant pressure sensors and fail safe mechanical switch

Provided is a self-calibrating system which self-calibrates for operation regardless of the particular reservoir or expansion tank, which further detects when a hydraulic fluid system adapted to a turf care machine has developed a leak and which warns the machine operator of such a leak before an appreciable amount of hydraulic fluid is allowed to leak from the system. The system includes a reservoir for holding a quantity of hydraulic fluid. The reservoir is connected via a connecting tube or hose located at the upper-most portion of the reservoir and connected to an expansion tank mounted substantially adjacent to the reservoir. The expansion tank includes a fitting having an elongated tube extending down into the expansion tank. The end of this tube is maintained substantially below the level of hydraulic fluid in the expansion tank during operation of the turf care machine to which it is attached. As the machine is operated, the hydraulic fluid expands with rising temperatures, and the connecting tube communicates the expanding fluid to the expansion tank. When operation of the machine is discontinued the hydraulic fluid contracts as it cools. As the hydraulic fluid contracts, the hydraulic fluid in the expansion tank is automatically drawn by a siphoning action through the elongated tube within the expansion tank through the connecting tube and back into the reservoir. The self-calibrating leak detection system is adaptable to a variety of self propelled machines having hydraulically actuated devices. In particular, significant savings could be gained by the early detection of hydraulic system leaks on large, earth-moving equipment and the like. Further, the self-calibrating hydraulic fluid leak detection system may be retrofit onto existing hydraulic systems by the addition of an expansion tank to the hydraulic system reservoir.

Retrofit hydraulic fluid leak detection system

A hydraulic fluid lead detection system which self-calibrates for operation regardless of the particular reservoir or expansion tank. A reservoir stores a quantity of hydraulic fluid and is connected via a connecting tube or hose located at the upper-most portion of the reservoir and connected to an expansion tank mounted substantially adjacent to the reservoir. An elongated tube extends down into the expansion tank. The end of this tube is maintained substantially below the level of hydraulic fluid in the expansion tank during operation of the turf care machine. During operation, the hydraulic fluid expands with rising temperatures, and the connecting tube communicates the expanding fluid to the expansion tank. A float type fluid level sensor measures the level of hydraulic fluid within the expansion tank and outputs an electronic signal corresponding to the fluid level in the expansion tank to the microcomputer based monitoring unit, which also senses the fluid temperature. The monitoring unit includes memory for storing a table of fluid temperatures versus fluid levels in the expansion tank stored during calibration of the system. During operation, the monitoring unit receives and interprets electronic signals from the float and temperature and compares the table values in memory to the values received from the float and temperature sensors to identify possible fluid leaks in the system.

Self-calibrating hydraulic fluid leak detection system

A system such as one for detecting when a hydraulic fluid system adapted to a turf care machine, has developed a leak and to warn the machine operator of such a leak before an appreciable amount of hydraulic fluid is allowed to leak from the system. The system includes a reservoir for holding a quantity of hydraulic fluid. The reservoir is connected via a connecting tube or hose to an expansion tank mounted adjacent to the reservoir. The expansion tank includes a fitting having an elongated tube extending down into the expansion tank. The end of this tube is maintained substantially below the level of hydraulic fluid in the expansion tank during operation of the turf care machine to which it is attached. As the machine is operated, the hydraulic fluid expands with rising temperature, and the connecting tube communicates the expanding fluid to the expansion tank. When operation of the machine is discontinued the hydraulic fluid contracts as it cools. As the hydraulic fluid contracts, the hydraulic fluid in the expansion tank, is automatically drawn by a siphoning action through the elongated tube within the expansion tank through the connecting tube and back into the reservoir. A float type fluid level sensor is provided and mounted to measure the level of hydraulic fluid within the expansion tank. The float level sensor sends an electronic signal corresponding to the fluid level in the expansion tank to a microcomputer based monitoring unit. The monitoring unit also senses the fluid temperature and interprets these electronic signals and, compensating for volumetric fluctuations due to the changing fluid temperature, and determines if conditions exist which indicate a hydraulic fluid leak exists. If such conditions exist, the monitoring unit produces a warning signal which is communicated to the vehicle operator.

Growing community of inventors

Fargo, ND, United States of America

Christopher L Young