Ground following harrow

Bruno Jacobo, Saskatoon (CA); Miit Nimish, Saskatoon (CA); Todd Hofmann, Saskatoon (CA)

USPTO: us-12622338 · published 2026-05-12 · patents · A01B 63/32· A01B 19/04· A01B 19/10

Ground following harrow

Todd Hofmann, Saskatoon (CA) , Miit Nimish, Saskatoon (CA) , Bruno Jacobo, Saskatoon (CA) This is my paper

Pith reviewed 2026-05-15 15:06 UTC · model grok-4.3

classification patents A01B 63/32A01B 19/04A01B 19/10

keywords frameharrowwhereinfrontrearattachedbeamoperating

0 comments

The pith

A harrow apparatus uses equal-length front and rear pivoting arms attached to a rearward beam to maintain horizontal orientation and ground engagement on uneven terrain.

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

The device is a farm implement with rows of downward tines dragged through soil. It rides on wheels and carries the harrow section on a mounting frame that can be raised or lowered. Two arms of equal length connect the harrow to a horizontal beam above it, one sloping down and back, the other down and forward. This arrangement forms a linkage that lets the harrow section rise and fall with the ground while staying roughly level, so the tines keep consistent contact without tilting.

Core claim

When the implement frame and harrow section are located on a substantially horizontal ground surface the beam is maintained in a position where an upper line joining the front and rear beam pivot axes is in a substantially horizontal orientation.

Load-bearing premise

The pivoting arms of equal length and the described attachment geometry will allow free vertical movement and sustained ground engagement without binding, excessive wear, or loss of tine depth control on real terrain.

read the original abstract

1 . A harrow apparatus comprising: an implement frame mounted on wheels for travel along a ground surface in an operating travel direction; a harrow section comprising a plurality of rows of tines, the rows of tines spaced rearward from a front row of tines to a rear row of tines, and oriented substantially perpendicular to the operating travel direction; wherein the tines are attached to a harrow frame and extend downward substantially an equal distance from the harrow frame; wherein the harrow section is attached to a mounting assembly extending rearward from the implement frame such that the harrow section engages the ground surface when in an operating position; wherein the mounting assembly is selectively movable upward and downward with respect to the implement frame to move the harrow section down into the operating position and up out of the operating position; wherein the mounting assembly comprises a beam extending rearward above the harrow frame; wherein the mounting assembly comprises front and rear arms pivotally attached at upper ends thereof to corresponding front and rear beam pivot axes located on the beam; wherein the front arm slopes downward and rearward to a lower end thereof that is pivotally attached to the harrow frame at a front frame pivot axis; wherein the rear arm slopes downward and forward to a lower end thereof that is pivotally attached to the harrow frame at a rear frame pivot axis located rearward of the front frame pivot axis; wherein the front and rear arms are substantially equal in length; wherein when the implement frame and harrow section are located on a substantially horizontal ground surface the beam is maintained in a position where an upper line joining the front and rear beam pivot axes is in a substantially horizontal orien

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.

Desk Editor's Note private letter to a colleague

This is a utility patent for an equal-arm crossed linkage that keeps a harrow beam level on flat ground while letting the section ride up and down; mechanically consistent but contains no data, comparisons, or performance claims.

read the letter

The core idea is a four-bar setup with front and rear arms of equal length, one sloping back and the other forward, pinned to a beam above the harrow frame. On level ground the upper pivots stay horizontal while the harrow can move vertically without tilting the beam. That geometry is spelled out clearly in the claims and does what the authors say it does on paper. The description is internally consistent and avoids any obvious binding or over-constraint in the linkage as drawn. Beyond that there is little to evaluate. No force calculations, no field measurements, no side-by-side comparison with existing floating-harrow mounts, and no statement of how much better ground contact or tine depth control actually becomes. The document is simply an apparatus claim. For someone designing or patenting tillage hardware the linkage sketch may be useful as prior art or as a starting point for further mechanical work. For anyone looking for evidence that the configuration improves efficiency, reduces wear, or outperforms current commercial designs, the filing supplies none. It is not a research result and does not pretend to be one. I would not bring it to a reading group, would not cite it in scientific work, and would not send it to referees; it belongs in a patent office file, not a journal.

Referee Report

1 major / 1 minor

Summary. The manuscript is a utility patent abstract describing a harrow apparatus in which a harrow section is suspended from an implement frame via a mounting assembly consisting of a rearward-extending beam and two equal-length pivoting arms arranged in a crossed configuration (front arm sloping down-rearward, rear arm sloping down-forward). The geometry is asserted to keep the beam horizontal on level ground while allowing vertical travel of the harrow section for ground following.

Significance. If the linkage functions as described, the design could improve consistency of tine depth on undulating terrain compared with rigid or single-pivot mounts. No kinematic analysis, force balance, wear estimates, or field data are supplied, so the practical advantage cannot be quantified from the given text.

major comments (1)

[Abstract] Abstract (final sentence): the assertion that the upper line joining the beam pivot axes remains substantially horizontal on level ground is presented as a direct consequence of equal arm lengths and the described attachment points, yet no geometric derivation, instantaneous-center calculation, or even a simple diagram is provided to confirm that the four-bar linkage actually produces this motion without binding or loss of parallelism over the intended vertical range.

minor comments (1)

[Abstract] The abstract is truncated mid-word (“orien”).

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for identifying the missing justification for the claimed horizontal orientation of the beam. Because the document is a utility-patent abstract rather than a kinematics paper, we address the point by reference to the geometry already recited in the claims and by offering a concise clarification that can be added without altering the scope of the invention.

read point-by-point responses

Referee: [Abstract] Abstract (final sentence): the assertion that the upper line joining the beam pivot axes remains substantially horizontal on level ground is presented as a direct consequence of equal arm lengths and the described attachment points, yet no geometric derivation, instantaneous-center calculation, or even a simple diagram is provided to confirm that the four-bar linkage actually produces this motion without binding or loss of parallelism over the intended vertical range.

Authors: The recited structure is a crossed four-bar linkage in which the two arms are of equal length and the upper and lower pivot spacings are equal; this geometry forms a parallelogram that keeps the beam parallel to the harrow frame at every height. The patent drawings (standard in a utility application) illustrate the configuration across the full range of motion and confirm absence of binding. We will append a single sentence to the abstract explicitly noting that the equal-length crossed arms produce a parallelogram linkage, thereby preserving horizontal orientation of the beam. revision: yes

Circularity Check

0 steps flagged

No significant circularity

full rationale

The document is a utility patent abstract that purely describes a mechanical harrow apparatus and its four-bar linkage mounting geometry. No equations, fitted parameters, predictions, derivations, or self-citations exist; the geometry is asserted directly as part of the apparatus definition rather than obtained from any prior result or self-referential step. The central claim is therefore self-contained and non-circular.

Axiom & Free-Parameter Ledger

0 free parameters · 0 axioms · 0 invented entities

No free parameters, mathematical axioms, or postulated entities are present; the document is a descriptive patent claim for a linkage geometry.

pith-pipeline@v0.9.0 · 5612 in / 921 out tokens · 50423 ms · 2026-05-15T15:06:25.390262+00:00 · methodology

discussion (0)

Lean theorems connected to this paper

Citations machine-checked in the Pith Canon. Every link opens the source theorem in the public Lean library.

IndisputableMonolith/Foundation/RealityFromDistinction.lean reality_from_one_distinction unclear

?

unclear
Relation between the paper passage and the cited Recognition theorem.

front and rear arms are substantially equal in length; when the implement frame and harrow section are located on a substantially horizontal ground surface the beam is maintained in a position where an upper line joining the front and rear beam pivot axes is in a substantially horizontal orientation
IndisputableMonolith/Cost/FunctionalEquation.lean washburn_uniqueness_aczel unclear

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unclear
Relation between the paper passage and the cited Recognition theorem.

front and rear arms pivotally attached at upper ends thereof to corresponding front and rear beam pivot axes

What do these tags mean?

matches: The paper's claim is directly supported by a theorem in the formal canon.
supports: The theorem supports part of the paper's argument, but the paper may add assumptions or extra steps.
extends: The paper goes beyond the formal theorem; the theorem is a base layer rather than the whole result.
uses: The paper appears to rely on the theorem as machinery.
contradicts: The paper's claim conflicts with a theorem or certificate in the canon.
unclear: Pith found a possible connection, but the passage is too broad, indirect, or ambiguous to say the theorem truly supports the claim.