Upping the Ante on Dozers

Komatsu's Palm Command Control System (PCCS) joystick controls all directional movements, including forward, reverse, left, right and counter-rotation. "From our smallest to our largest machines, steering and blade control are common," says Warner. "The PCCS joysticks are ergonomically designed to fit the typical operator's hand. The handle is at an angle so when the operator sits in the seat with his arm on the armrest, the control fits very naturally into his hand."

Thumb push buttons are incorporated into the joystick of Komatsu's larger, torque converter machines for transmission gear shifting. Thompson welcomes this feature on his D61. "With the older machines, a gear pattern was controlled with your whole arm," he recalls. "Now, all I have to do is hold my hand still and press the button with my thumb."

In the case of Deere machines, one joystick operates the transmission (steering, speed and direction), while another controls the blade. A single pedal combines the decelerator and brake function. "Pilot pressure hydraulics and electronic transmission control have dramatically reduced lever efforts," Errthum says. "As a result, the operator can work longer stretches without a break, and feels better going home at night."

Improved blade control
Blade controls have received a facelift similar to that of directional controls.

For example, engineers for New Holland machines have designed an ergonomic palm grip for ease of effort and multiple settings. "The new grip gives the operator a better feel for the blade's movement," says DeHoyos. "Having the ability to move the blade in a variety of positions is popular, as well. Six-way blades used to fit the bill . . . But today, more [manufacturers] are also including variable blade pitch adjusters, which allow the operator to adjust the pitch of the blade for better finish grading or excavation."

Deere has introduced new valve profiles to allow for consistent performance on hot or cold hydraulics, notes Errthum, and load-sensing hydraulics ensure consistent blade response regardless of the load. "All of these combine to make the blade an intuitive tool for the operator," he says. "The vehicle becomes less of a complex machine and more similar to a mason's trowel."

Thompson and his employees appreciate the ease of operation in both directional and blade controls. "Controls have changed dramatically, even since the late 1980s and 1990s," he says. "Those machines had a single control lever that was bulky and about 24 to 30 in. With the joystick controls, the machine responds instantly with just a touch. To get full blade control, you only have to move about 3 in. It's a whole lot faster response time. It's also smooth movement of the machine instead of a jerking motion."

Controlling speed
Features incorporated into today's dozers also provide for better control of operating speed.

New Holland models delivers multiple ground speed settings that are adjustable through the use of the control lever. In addition, a reverse ratio control allows operators to adjust reverse speed in contrast to forward speed. "Since a typical application requires a dozer to move in reverse 50% of the time, the reverse ratio control comes in handy when you're maximizing production and extending the life of your undercarriage," says DeHoyos.

Deere dozers feature sensitivity settings for steering, direction changes and engine lugging. The machines also allow the operator to select whether the decelerator slows the engine and transmission or transmission only, where the operator can maintain full power to the tracks and implements while slowing the tracks with the decelerator.

Ultimately, the changes in dozer designs have helped to improve production and the quality of work, says Thompson. "We get a lot smoother finish with a lot less time spent on fine grading work," he asserts. "We don't have to redo it with another application to get a finished product. These changes have helped speed up our entire process."