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US3887012A Expired / Lapsed US ⏱️ 0.0 years remaining

Automatic levelling system for earth working blades and the like

Assignee: Caterpillar Inc
•
Filing: 1973-12-03
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Granted: 1975-06-03
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Expires: 1993-12-03
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Abstract

Abstract A laser beam or like radiant energy source is swept in a reference plane in order to generate pulsating radiant energy within the plane so a system can automatically adjust an earth working blade or the like in reference thereto. A special receiver is attached to the blade which has a plurality of vertically spaced energy receiving regions formed by solar cells or the like, arranged so each of the regions is isolated from the others so that only one region is excited by the beam at a given time. A central region in the receiver corresponds to a null point and circuitry in the system employs digital gating elements to avoid ambiguities and to effect relative fast blade movement when the null point of the receiver is out of the plane by a relatively large amount and relatively slow movement when the null point is only slightly off the plane.

Inventors

  • 👤 Rolland Dale Scholl
  • 👤 Donald Frederick Coleman
  • 👤 Edward Lawrence Johnson
  • 👤 William Edward Streight

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 04:27
CPC Classifications
G; G01; G01C; G01C15/00; G01C15/002; G01C15/004; G01C15/006; E; E02; E02F; E02F3/00; E02F3/04; E02F3/76; E02F3/80; E02F3/84; E02F3/844; E02F3/847; Y; Y10; Y10S; Y10S37/00; Y10S37/907

Claims Analysis

Total Claims: 13
Claim 1
Independent Claim 222 words
In an earthworking implement control system for maintaining an implement in a fixed relationship to a plane comprising means for producng a narrow beam of radiant energy of a fixed wave length, means for sweeping said beam throughout the plane to produce pulsating radiation at any site in the plane, a multidirectional receiving control mounted on the implement for receiving the beam comprising a receiving means including a plurality of sets of at least two series connected angularly disposed light actuated cells for producing an electric signal in response to impingement of said beam thereon, spacer means for supporting said sets of cells in a stacked vertical relationship so that there is at least a first set of said cells and a second set of said cells spaced from said first set across a null region, a plurality of mutually parallel opaque planar members horizontally disposed on opposite sides of said sets of cells and thereby defining said null region between said sets so said planar members are operable to define at least three beam defining channels, and circuit and power means responsive to an electric signal from said cells for moving said implement in a direction when one of said sets produces an electrical signal whereby the null region of said receiving means is moved into the plane of said beam.
Claim 2
Dependent Claim 222 words
In an earthworking implement control system for maintaining an implement in a fixed relationship to a plane comprising means for producng a narrow beam of radiant energy of a fixed wave length, means for sweeping said beam throughout the plane to produce pulsating radiation at any site in the plane, a multidirectional receiving control mounted on the implement for receiving the beam comprising a receiving means including a plurality of sets of at least two series connected angularly disposed light actuated cells for producing an electric signal in response to impingement of said beam thereon, spacer means for supporting said sets of cells in a stacked vertical relationship so that there is at least a first set of said cells and a second set of said cells spaced from said first set across a null region, a plurality of mutually parallel opaque planar members horizontally disposed on opposite sides of said sets of cells and thereby defining said null region between said sets so said planar members are operable to define at least three beam defining channels, and circuit and power means responsive to an electric signal from said cells for moving said implement in a direction when one of said sets produces an electrical signal whereby the null region of said receiving means is moved into the plane of said beam.
Claim 3
Dependent Claim 222 words
In an earthworking implement control system for maintaining an implement in a fixed relationship to a plane comprising means for producng a narrow beam of radiant energy of a fixed wave length, means for sweeping said beam throughout the plane to produce pulsating radiation at any site in the plane, a multidirectional receiving control mounted on the implement for receiving the beam comprising a receiving means including a plurality of sets of at least two series connected angularly disposed light actuated cells for producing an electric signal in response to impingement of said beam thereon, spacer means for supporting said sets of cells in a stacked vertical relationship so that there is at least a first set of said cells and a second set of said cells spaced from said first set across a null region, a plurality of mutually parallel opaque planar members horizontally disposed on opposite sides of said sets of cells and thereby defining said null region between said sets so said planar members are operable to define at least three beam defining channels, and circuit and power means responsive to an electric signal from said cells for moving said implement in a direction when one of said sets produces an electrical signal whereby the null region of said receiving means is moved into the plane of said beam.
Claim 4
Dependent Claim 222 words
In an earthworking implement control system for maintaining an implement in a fixed relationship to a plane comprising means for producng a narrow beam of radiant energy of a fixed wave length, means for sweeping said beam throughout the plane to produce pulsating radiation at any site in the plane, a multidirectional receiving control mounted on the implement for receiving the beam comprising a receiving means including a plurality of sets of at least two series connected angularly disposed light actuated cells for producing an electric signal in response to impingement of said beam thereon, spacer means for supporting said sets of cells in a stacked vertical relationship so that there is at least a first set of said cells and a second set of said cells spaced from said first set across a null region, a plurality of mutually parallel opaque planar members horizontally disposed on opposite sides of said sets of cells and thereby defining said null region between said sets so said planar members are operable to define at least three beam defining channels, and circuit and power means responsive to an electric signal from said cells for moving said implement in a direction when one of said sets produces an electrical signal whereby the null region of said receiving means is moved into the plane of said beam.
Claim 5
Dependent Claim 31 words
The receiving control defined in claim 1 wherein the receiving means includes filtering means for excluding Radiant energy from the cells at wave lengths below that of said beam producing means.
Claim 6
Dependent Claim 34 words
The receiving control defined in claim 2 wherein said filtering means includes a deformable tinted impervious plastic sheet overlying the peripheral edges of the opaque planar members for excluding deleterious matter from the channels.
Claim 7
Dependent Claim 56 words
The receiving control defined in claim 1 wherein the individual cells of each said set are angularly displaced from one another by an angle of about 60* so that the receiving means has a substantially flat response to beams impinging thereon from all directions within + or - 90* of a plane bisecting the 60* angle.
Claim 8
Dependent Claim 56 words
The receiving control defined in claim 1 in combination with a plurality of third cells one of which is associated with each said set of cells, the individuall cells of each set being displaced about 60* from one another so that said receiving means has a substantially flat response to beams impinging thereon from all directions.
Claim 9
Dependent Claim 66 words
The receiving control defined in claim 1 including a third set of cells adjacent said first set and opposite said null region and a fourth set of cells adjacent said second set and opposite said null region, whereby the circuit and power means responding to said third and fourth sets of said cells moves the implement faster than when responding to said first and second sets.
Claim 10
Dependent Claim 65 words
The receiving control defined in claim 1 wherein circuit and power means comprises a source of pressurized fluid, a double acting cylinder having a piston and rod in driving relation to said implement, a valve for controllably delivering fluid to said cylinder to selectively move said piston in said cylinder, and electrical means for controlling said valve in response to the signals from the cells.
Claim 11
Dependent Claim 65 words
The receiving control defined in claim 7 wherein the electrical means comprises circuit means for producing a DC signal having a first polarity when said receiving means is in a position such that the beam impinges on said first set of cells and a second polarity when said receiving means is in a position such that the beam impinges on said second set of cells.
Claim 12
Dependent Claim 209 words
The receiving control defined in claim 8 wherein said DC signal producing means including means for connecting the cells of said first set in series opposition of the cells of said second set so that the polarity of the output voltage is indicative of the direction that the receiving means is displaced from said plane, first and second comparators having input terminals connected to the series connected cells, said first comparator producing an output signal when said first set of cells receives said beam and said second comparator producing an output signal when said second set of cells receives said beam, logic means for generating an inverse of the output of said first comparator, logic means for generating an inverse of the output of said second comparator, a first gate for producing a first control signal when there coexists at the input thereof an output signal from said first comparator and the inverse of said second comparator, a second gate for producing a second control signal when there coexists at the input thereof an output from said second comparator and the inverse of said first comparator, means for inverting the output of said first gate, and means for combining the outputs of said inverting means and said second gate.
Claim 13
Dependent Claim 188 words
The receiving control defined in claim 6 wherein said circuit and power means includes means for generating an A binary signal responsive to impingement of said beam on said first set of light activated cells, a B binary signal responsive to impingement of said beam on said second set of light activated cells, a C binary signal responsive to impingement of said beam on said third set of light activated cells, and a D binary signal responsive to impingement of said beam on said fourth set of light activated cells, first logic means responsive to the signals A.B.C.D and B.A.C.D for transmitting to the power means a signal of relative low magnitude of approprate polarity to move the implement and sets of cells in a direction to bring said null region of said receiving control into the plane, and second logic means responsive to the signals C.B.D and D.A.C for transmitting to said circuit and power means a relatively high magnitude signal of appropriate polarity to move the implement and sets of cells in a direction to bring said null region of said receiving means into the plane.

References Cited (Backward Citations)

US2916836A Cited
US3227929A Cited
US3340763A Cited
US3494426A Cited
US3480783A Cited
US3554291A Cited
US3641351A Cited
US3604512A Cited
US3771876A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1978-06-02 1978-12-02 1979-06-03 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1982-06-02 1982-12-02 1983-06-03 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1986-06-02 1986-12-02 1987-06-03 $7700.00 Window Closed / Lapsed

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