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US 2025/0043531 A1Published application
Compact utility loader with load-sensing variable length lift arm assembly
AssigneeThe Toro Company
InventorsJohn P. Azure, Jeffrey R. Frank, David A. Murray
Life of this patent
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Abstract
A compact utility loader incorporating a boom of adjustable length. The boom may include one or more lift arm assemblies, with each lift arm assembly including a first lift arm that telescopically receives a second lift arm. Each lift arm assembly also includes a telescoping actuator adapted to telescopically extend and retract its second lift arm relative to its first lift arm. A load-sensing system may be provided and adapted to limit lift arm assembly extension based at least in part upon a tool load applied at a tool supported by the boom.
Claims17
-14. (canceled)
A compact utility loader comprising:
- a frame;
- ground-engaging members operatively attached to the frame;
- a lift arm assembly operatively attached to the frame, wherein the lift arm assembly comprises a first lift arm and a second lift arm that is slidingly engaged with the first lift arm, and wherein the lift arm assembly is pivotally attached to the frame at a lift arm pivot axis;
- a hydraulic lift actuator adapted to pivot the lift arm assembly about the lift arm pivot axis, the lift actuator comprising an extension side and a retraction side;
- a hydraulic extension actuator adapted to extend and retract the second lift arm relative to the first lift arm, wherein the extension actuator also comprises an extension side and a retraction side;
- and
- a differential pressure switch associated with the lift actuator and adapted to detect a threshold differential pressure between the extension side and the retraction side of the lift actuator, whereby extension of the extension actuator is disabled when the threshold differential pressure is detected.
4 more elements
A compact utility loader comprising:
- a frame;
- ground-engaging members operatively attached to the frame;
- a lift arm assembly operatively attached to the frame, wherein the lift arm assembly comprises a first lift arm and a second lift arm that is slidingly engaged with the first lift arm, and wherein the lift arm assembly is pivotally attached to the frame at a lift arm pivot axis;
- a hydraulic lift actuator adapted to pivot the lift arm assembly about the lift arm pivot axis, the lift actuator comprising an extension side and a retraction side;
- a hydraulic extension actuator adapted to extend and retract the second lift arm relative to the first lift arm, wherein the extension actuator also comprises an extension side and a retraction side;
- a working tool carried by the lift arm assembly;
- and
- a differential pressure switch associated with the lift actuator and adapted to detect when a load at the working tool is sufficient to cause a moment at the frame that exceeds a predetermined threshold moment.
5 more elements
A method of operating a lift arm assembly of a compact utility loader comprising:
- providing the compact utility loader comprising:
- a frame;
- ground-engaging members operatively attached to the frame;
- a control console located at or near a rear end of the frame, the control console carrying controls adapted to be manipulated by an operator either:
- standing on a platform mounted near the rear end of the frame;
- or walking behind the frame;
- a lift arm assembly operatively attached to the frame, wherein the lift arm assembly comprises a rear lift arm and a front lift arm that is slidingly engaged with the rear lift arm, and wherein the lift arm assembly is pivotally attached to the frame at a lift arm pivot axis;
- a hydraulic lift cylinder adapted to pivot the lift arm assembly about the lift arm pivot axis, the lift cylinder comprising an extension side and a retraction side;
- a hydraulic extension cylinder adapted to extend and retract the front lift arm relative to the rear lift arm;
- and
- a working tool attached at or near a front end of the front lift arm;
- extending or retracting the lift cylinder;
- sensing a moment applied to the frame resulting from a load carried by the working tool, wherein the moment is sensed by detecting a threshold differential pressure between the extension side and the retraction side of the lift cylinder;
- and
- restricting extension of the extension cylinder when the threshold differential pressure is detected.
12 more elements
Dependencies are inferred from the claim text.