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US 12,146,287 B2Granted
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
Estimating the term…
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.
Claims14
A compact utility loader comprising:
- a frame;
- ground-engaging members operatively attached to the frame, wherein at least one of the ground-engaging members is powered to propel the frame over a surface;
- a lift arm assembly operatively attached to the frame, wherein the lift arm assembly comprises first and second lift arms telescopically engaged with one another, 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 telescoping actuator adapted to telescopically extend and retract the second lift arm relative to the first lift arm, wherein the telescoping 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.
4 more elements
A compact utility loader comprising:
- a frame;
- ground-engaging members operatively attached to the frame, wherein at least one of the ground-engaging members is powered to propel the frame over a surface;
- 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 attached to at least one of a first and second side of the frame, wherein the lift arm assembly comprises:
- an elongate rear lift arm including a front end and a rear end, wherein the rear end of the rear lift arm is pivotally attached to the frame at a lift arm pivot axis;
- and
- an elongate front lift arm also including a front end and a rear end, wherein the rear end of the front lift arm is telescopically received in the front end of the rear lift arm such that a distance between the rear end of the rear lift arm and the front end of the front lift arm is variable;
- 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 telescoping cylinder adapted to telescopically extend and retract the front lift arm relative to the rear lift arm;
- and
- a differential pressure switch associated with the lift cylinder and adapted to detect a threshold differential pressure between the extension side and the retraction side of the lift cylinder.
10 more elements
A compact utility loader comprising:
- a frame;
- ground-engaging members operatively attached to the frame, wherein at least one of the ground-engaging members is powered to propel the frame over a surface;
- a lift arm assembly operatively attached to the frame, wherein the lift arm assembly comprises first and second lift arms telescopically engaged with one another, 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 telescoping cylinder adapted to telescopically extend and retract a front lift arm relative to a rear lift arm, wherein the telescoping cylinder also comprises an extension side and a retraction side;
- a differential pressure switch associated with the lift cylinder and adapted to detect a threshold differential pressure between the extension side and the retraction side of the lift cylinder;
- and
- a sequence valve connected to the retraction side of the lift cylinder, wherein the sequence valve comprises a first position in which hydraulic fluid in the retraction side of the lift cylinder is isolated from other hydraulic components of the loader.
5 more elements
Dependencies are inferred from the claim text.