Clark Equipment Compnay

Doosan Bobcat North America Inc.

David Glasser

Daniel J Krieger

Jonathan J Roehrl

Ronald S Hansen

Brian P Dehnert

Cody Erhardt

Matthew Kaldor

Kevin Joseph Zent

Scott J LaCoe

Scott Lacoe

A lift arm assembly for a power machine can include a lift arm, an implement carrier, a lift cylinder that raises or lowers the lift arm, a leveling link, a tilt cylinder that causes the implement carrier to pivot relative to the lift arm, and an isolated hydraulic circuit. The isolated hydraulic circuit can include a follower cylinder that is mechanically synchronized with the lift cylinder, a leveling cylinder that can be pivotally secured to the leveling link and to the lift arm, a first conduit that can provide hydraulic flow between base ends of the follower and leveling cylinders, and a second conduit that can provide hydraulic flow between rod ends of the follower and leveling cylinders. Movement of the follower and leveling cylinders can be hydraulically synchronized by flow through the first and second conduits.

Self-leveling lift arm assembly for power machines

Disclosed are front entry cabs, and power machines with front entry cabs, having a door that is moveable between opened and closed positions. In the opened position, the door is positioned within an operator compartment of the cab above the operator seat and below a top of the cab. A linkage system defines the travel path of the door between closed and opened positions. The linkage system is configured to minimize interference with operator visibility.

Cab door

A hydraulic assembly for an extendable lift arm assembly can include an extension cylinder, a leveling cylinder, a main control valve, a flow combiner/divider, and one or more flow-blocking arrangements. The main control valve can be configured to control commanded movement of the extension and leveling cylinders of the lift arm assembly. The flow combiner/divider can be configured to hydraulically link the extension cylinder with the leveling cylinder for synchronized operation of the extension cylinder and the leveling cylinder. The one or more flow-blocking arrangements can be configured to restrict flow from rod or base ends of the leveling or extension cylinders during commanded extension or retraction of the leveling and extension cylinders, or in the absence of commanded movement of the leveling and extension cylinders, to maintain synchronized orientation of the leveling and extension cylinders.

Hydraulic leveling circuit for power machines

Disclosed embodiments include power machines, such as front-end loaders and utility vehicles, with a lift arm and a bucket leveling system utilizing four-bar linkages which mechanically level an attached implement as the lift arm is raised and lowered.

Lift arm leveling system

Power machines such as excavators having a house that rotates about a vertical axis on an undercarriage are disclosed. In certain conditions, a control system on the excavator can limit rotational movement of the house and/or pivoting of a swing function on a lift arm to contain work performed by an implement to a predefined range or work area.

Growing community of inventors

Bismarck, ND, United States of America

David Glasser