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US4198006A Expired / Lapsed US ⏱️ 0.0 years remaining

Magnetic clearance sensor

Assignee: Blue Leaf IP Inc
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Filing: 1978-10-30
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Granted: 1980-04-15
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Expires: 1998-10-30
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Abstract

Abstract Magnetic-electronic apparatus for sensing the clearance between two ferrous metals, for application in measuring the clearance between a shear bar and the cutting knives of a harvesting farm machine, is disclosed having a magnetic sensor disposed within the shear bar for producing a magnetic field, the interception of which by the passage of a knife produces an electronic signal which is processed by appropriate circuitry for indicating the clearance between the knives and the shear bar.

Inventors

  • 👤 Norman F. Rolfe

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 16:08
CPC Classifications
A; A01; A01F; A01F29/00; A01F29/09; A01F29/095; B; B02; B02C; B02C18/00; B02C18/06; B02C18/16; B02C25/00; B26; B26D; B26D7/00; B26D7/26; B26D7/2628; G; G01; G01B; G01B7/00; G01B7/14

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 155 words
In a circuit for providing a clearance signal proportional to the clearance between opposing portions of proximal ferrous elements in relative motion including magnetic field generating means cooperating with one of said ferrous elements forming a portion thereof and generating a magnetic field emanating from the generating means and outwardly from the opposing portion of said one of said ferrous elements to be intercepted by said other ferrous element for providing an intercept signal, the improvement comprising: circuit means cooperating with said field generating means and responsive to said intercept signal, said circuit means includes a gating circuit responsive to said intercept signal and having at least one preset threshold, and integrator means responsive to said intercept signal and said gating circuit during the time that the intercept signal exceeds the preset threshold for providing an integrated clearance signal related to the maximum flux through the generating means as said other element intercepts said field.
Claim 2
Dependent Claim 155 words
In a circuit for providing a clearance signal proportional to the clearance between opposing portions of proximal ferrous elements in relative motion including magnetic field generating means cooperating with one of said ferrous elements forming a portion thereof and generating a magnetic field emanating from the generating means and outwardly from the opposing portion of said one of said ferrous elements to be intercepted by said other ferrous element for providing an intercept signal, the improvement comprising: circuit means cooperating with said field generating means and responsive to said intercept signal, said circuit means includes a gating circuit responsive to said intercept signal and having at least one preset threshold, and integrator means responsive to said intercept signal and said gating circuit during the time that the intercept signal exceeds the preset threshold for providing an integrated clearance signal related to the maximum flux through the generating means as said other element intercepts said field.
Claim 3
Dependent Claim 151 words
In combination with a forage harvester having a cutter head, including a plurality of knives thereon, and a shear bar, apparatus for providing a clearance signal proportional to the clearance between a knife and the shear bar comprising: magnetic field generating means cooperating with the shear bar forming a face portion thereof and generating a magnetic field emanating from the generating means and outwardly therefrom to be intercepted by said knife in relative motion with the shear bar for providing an intercept signal, circuit means cooperating with said field generating means and responsive to said intercept signal, said circuit means includes a gating circuit responsive to said intercept signal and having at least one preset threshold, and integrator means responsive to said intercept signal and said gating circuit during the time that the intercept signal exceeds the preset threshold for providing an integrated clearance signal as said knife intercepts said field.
Claim 4
Dependent Claim 151 words
In combination with a forage harvester having a cutter head, including a plurality of knives thereon, and a shear bar, apparatus for providing a clearance signal proportional to the clearance between a knife and the shear bar comprising: magnetic field generating means cooperating with the shear bar forming a face portion thereof and generating a magnetic field emanating from the generating means and outwardly therefrom to be intercepted by said knife in relative motion with the shear bar for providing an intercept signal, circuit means cooperating with said field generating means and responsive to said intercept signal, said circuit means includes a gating circuit responsive to said intercept signal and having at least one preset threshold, and integrator means responsive to said intercept signal and said gating circuit during the time that the intercept signal exceeds the preset threshold for providing an integrated clearance signal as said knife intercepts said field.
Claim 5
Dependent Claim 43 words
In a circuit for providing the clearance signal between opposing portions of proximal elements according to claims 1 or 2 further including peak detector means responsive to said integrated clearance signal for providing a peak integrated signal, which is proportional to minimum clearance.
Claim 6
Dependent Claim 41 words
In a circuit for providing a clearance signal proportional to the clearance between opposing portions of proximal elements according to claims 1 or 2 further including low pass filter means responsive to said integrated signal for providing an average clearance signal.
Claim 7
Dependent Claim 54 words
In a circuit for providing a clearance signal proportional to the clearance between opposing portions of proximal elements according to claims 1 or 2 further including sampling means responsive to the gating circuit and the integrated clearance signal, and detector means responsive to the minimum integrated clearance signal for providing a maximum clearance signal.

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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1983-04-15 1983-10-15 1984-04-15 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1987-04-15 1987-10-15 1988-04-15 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1991-04-15 1991-10-15 1992-04-15 $7700.00 Window Closed / Lapsed

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