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USPTO: us-12648500 · published 2026-06-09 · patents · A01B 63/1006· A01B 59/0415· F15B 11/22· F15B 2211/50554

Arrangement for controlling a hydraulic three-point hitch

Pith reviewed 2026-06-09 15:01 UTC · model grok-4.3

classification patents A01B 63/1006A01B 59/0415F15B 11/22F15B 2211/50554
keywords hydraulic three-point hitchseat valvepressure compensation valvehydraulic cylinderworking chamberhydraulic reservoirlifting positionfluid flow control
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The pith

A hydraulic three-point hitch control routes flow through two seat valves each preceded by its own upstream pressure compensation valve.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper presents an arrangement for controlling a hydraulic three-point hitch. A hydraulic cylinder uses pressurized fluid in its working chamber to change the lifting position of the lower arm. Two seat valves manage the connections: one selectively links the chamber to a high-pressure source and the other creates a return path to the reservoir. A first pressure compensation valve sits upstream of the first seat valve in the inflow direction, while a second sits upstream of the second seat valve in the outflow direction. The design separates pressure regulation for each flow path to support controlled raising and lowering of the hitch.

Core claim

The central claim is an arrangement for controlling a hydraulic three-point hitch comprising a hydraulic cylinder with a working chamber, a first seat valve producing a flow connection to a high-pressure source, a second seat valve producing a return connection to a hydraulic reservoir, a first pressure compensation valve connected upstream of the first seat valve in a first through-flow direction, and a second pressure compensation valve connected upstream of the second seat valve in a second through-flow direction.

What carries the argument

The pair of pressure compensation valves placed upstream of their respective seat valves, which regulate pressure independently for inflow from the high-pressure source and outflow to the reservoir before fluid reaches the working chamber.

If this is right

  • Pressurized fluid can reach the working chamber through the first compensated seat valve to raise the lower arm.
  • Fluid can exit the working chamber through the second compensated seat valve to lower the arm under controlled conditions.
  • Each direction of fluid movement receives dedicated pressure compensation before the seat valve opens or closes.
  • The cylinder position changes only when the selected seat valve permits flow after compensation.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • The layout could extend to other single-acting hydraulic actuators where independent inflow and outflow regulation is needed.
  • Electronic control signals sent to the seat valves might achieve finer position holding if the compensators reduce pressure spikes.
  • Tractor manufacturers could test whether this valve order reduces heat generation during prolonged hitch adjustments compared with conventional circuits.

Load-bearing premise

The upstream placement of the pressure compensation valves relative to each seat valve delivers functional advantages in control or efficiency.

What would settle it

A side-by-side test on the same hitch showing identical lifting accuracy, response speed, and energy use when the pressure compensation valves are moved downstream or removed would falsify the benefit of the upstream placement.

read the original abstract

1 . An arrangement for controlling a hydraulic three-point hitch, comprising: a hydraulic cylinder including a working chamber, by which pressurized hydraulic fluid changes a lifting position of a lower arm of the hydraulic three-point hitch; a first seat valve and a second seat valve in fluid communication with the working chamber, the first seat valve selectively producing a flow connection to a high-pressure source, and the second seat valve selectively producing a return connection to a hydraulic reservoir; a first pressure compensation valve connected upstream of the first seat valve in a first through-flow direction; and a second pressure compensation valve connected upstream of the second seat valve in a second through-flow direction.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

0 major / 1 minor

Summary. The manuscript describes an arrangement for controlling a hydraulic three-point hitch comprising a hydraulic cylinder with a working chamber, a first seat valve selectively connecting to a high-pressure source, a second seat valve for return to a reservoir, and first and second pressure compensation valves connected upstream of each seat valve in their respective through-flow directions.

Significance. If the upstream placement of the pressure compensation valves confers control or efficiency benefits in hydraulic systems for agricultural equipment, the design could have practical value; however, the complete absence of performance data, comparisons, simulations, or validation makes any assessment of significance speculative.

minor comments (1)
  1. The document is presented solely as a numbered patent claim without standard scientific paper elements such as methods, results, analysis, or discussion sections.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for reviewing our patent description. The document presents a novel hydraulic arrangement for a three-point hitch control system. We address the concern regarding performance data below.

read point-by-point responses
  1. Referee: The complete absence of performance data, comparisons, simulations, or validation makes any assessment of significance speculative.

    Authors: This is a patent document whose purpose is to disclose the inventive arrangement of a hydraulic cylinder, seat valves, and upstream pressure compensation valves. Patent specifications describe the technical structure and claimed novelty without including experimental data, which is outside the scope of patent filings. The potential control or efficiency benefits arise from the specific upstream placement of the compensation valves in the through-flow directions, as detailed in the claims. We maintain that the significance can be evaluated from the described configuration itself. revision: no

Circularity Check

0 steps flagged

No significant circularity

full rationale

The document is a United States patent application whose central content is a legal description of a hydraulic circuit arrangement. It contains no equations, derivations, predictions, fitted parameters, or self-citations. The content is a direct component listing without any derivation chain or load-bearing steps that could reduce to inputs by construction.

Axiom & Free-Parameter Ledger

0 free parameters · 0 axioms · 0 invented entities

The document is a patent for a mechanical-hydraulic system and contains no mathematical derivations, fitted parameters, or postulated scientific entities.

pith-pipeline@v0.9.1-grok · 5655 in / 902 out tokens · 46227 ms · 2026-06-09T15:01:16.792373+00:00 · methodology

discussion (0)

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