OPENTECHNICAL PUBLICATION
OT-2026-000003217

Hydraulic boom platform leveling system

Published: 2026-09-15T19:51:15.645982Z
Permanent URL: https://opentechnical.org/p/OT-2026-000003217
Categories: Lifting, Positioning & Manipulation > Lift Tables and Positioners

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ABSTRACT

A platform leveling system for an aerial lift truck utilizes a master/slave
combination of helical hydraulic rotary actuators to automatically level the
work platform in response to movements of the boom. For a two-stage aerial
lift comprised of a lower boom and an upper boom, a first rotary actuator is
coupled to the base of the lower boom, a second rotary actuator is coupled to
the elbow where the upper boom is hinged to the lower boom, and a third rotary
actuator is coupled directly to the platform and upper boom. Movement of the
lower boom relative to the base causes the first rotary actuator to displace a
fixed amount of hydraulic fluid, and movement of the upper boom relative to
the lower boom caused the second rotary actuator to disperse a fixed amount of
hydraulic fluid. The displacement of hydraulic fluid in the first and second
rotary actuators (the master units) causes an equal amount of displacement in
the third rotary actuator (the slave unit), which results in articulating the
platform in direct response to movement of the boom in order to maintain the
platform in a level position.

1. Drawings

[0001] Sheet 1.

[0002] Sheet 2.

[0003] Sheet 3.

[0004] Sheet 4.

[0005] Sheet 5.

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OpenTechnical publication OT-2026-000003217
Published 2026-09-15T19:51:15.645982Z
https://opentechnical.org/p/OT-2026-000003217