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This is a record of a document published elsewhere, first published by the United States Patent and Trademark Office, as US-2001015129-A1, on 23 August 2001. OpenTechnical did not first disclose it. The identifier, hashes and timestamps below record what this library served and when, not when the material became public. View the original.

OT-2026-000003100

Hydraulic leveling control system for a loader type vehicle

Published
Permanent URL
Classification
Lifting, Positioning & Manipulation › Lift Tables and Positioners
Inventors
ALTMAN EUGENE, FREY BRIAN ANDREW
Original source
US-2001015129-A1, the United States Patent and Trademark Office, 23 August 2001
Document SHA-256
d3acced676ee5e8698cb9651ef9661ca336ec687c0884b875d9f8b876b782080

A hydraulic control system for controlling the orientation of a material handling unit on a lift boom. The control system includes a flow divider/combiner valve operative in a boom-raise, unit-leveling mode to pass a portion of the fluid displaced from the rod end of the boom cylinder to the base end of the unit cylinder, and operative in a boom-lower, unit-leveling mode, to combine the fluid stream displaced from the base end unit cylinder in a preset ratio with pressurized fluid, and pass the combined stream to the rod end of the boom cylinder. A modulating valve controls flow to and from the base end of the boom cylinder and is pilot actuated to inhibit descent of the boom until the pressure in the unit cylinder reaches a level at which the unit cylinder initiates levelling of the unit.

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Abstract

A hydraulic control system for controlling the orientation of a material handling unit on a lift boom. The control system includes a flow divider/combiner valve operative in a boom-raise, unit-leveling mode to pass a portion of the fluid displaced from the rod end of the boom cylinder to the base end of the unit cylinder, and operative in a boom-lower, unit-leveling mode, to combine the fluid stream displaced from the base end unit cylinder in a preset ratio with pressurized fluid, and pass the combined stream to the rod end of the boom cylinder. A modulating valve controls flow to and from the base end of the boom cylinder and is pilot actuated to inhibit descent of the boom until the pressure in the unit cylinder reaches a level at which the unit cylinder initiates levelling of the unit.

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Publication information

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Citation

OpenTechnical Publication OT-2026-000003100, “Hydraulic leveling control system for a loader type vehicle,” published September 15, 2026 at 19:28:59 UTC, https://opentechnical.org/p/OT-2026-000003100.

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