Abstract: An earthmoving apparatus and method for grading a tract of land to a desired finish contour wherein a continuously updated contour map is displayed to the operator of the earthmoving apparatus during the grading process is provided. The earthmoving apparatus has a blade of known width for cutting and filling soil of the tract of land. Vertical blade movement and the x and y position of the earthmoving apparatus is continually detected by respective sensors as the earthmoving apparatus traverses the tract of land. An ultrasonic transmitter and receiver detects elevation of the soil, preferably located behind the blade, to provide updated soil elevation information. A computer then uses the aforesaid information to generate a visual representation of a contour map of the tract of land with cut and fill lines thereon.

Abstract: An aircraft control system for applying chemicals to an agricultural field in one of a plurality of flight patterns is provided. A global positioning system receiver receives radio frequency signals from satellites and the position of the aircraft is determined from the information contained in the received signals. An aircraft computer stores the surface coordinates of the field to be sprayed. The aircraft pilot enters the desired orientation, swath width and track width of the flight pattern into the computer. Based on the aforementioned information, the computer produces a flight pattern having the desired orientation and generates, via a pilot headset, audible signals representative of amount and direction of deviation from the desired flight pattern. The computer means may also automatically activate and deactivate chemical spraying upon entering and exiting, respectfully, the airspace above the field.

Abstract: A laser beam target for use with a projector capable of providing a reference laser beam of light traveling in a predetermined path is provided and includes a main body portion having first and second surfaces. A plurality of projections are provided on at least one of the first and second surfaces for directing at least a portion of the reference beam of light into a specific range of vertical viewing angles away from the path of the beam as the light passes from the body, thereby permitting a worker viewing the target to more easily determine when the reference beam of light is in alignment with appropriate reference indicia on the target.

Abstract: A method and apparatus are provided for controlling the working depth of a bucket for an excavating machine having an outreach boom which is pivotally attached at one end to the machine, a downreach boom pivotally attached to the opposite end of the outreach boom, a digging bucket pivotally attached to the end of the downreach boom opposite to that to which the outreach boom is attached, and hydraulic power cylinders for moving the pivotally interconnected elements. A laser beam is projected at a reference height and a beam sensor mounted on the outreach boom of the machine detects the beam by means of a plurality of individual sensor locations. The angular orientation of the downreach boom relative to vertical is detected and a microprocessor controller connected to the beam sensor and the angle sensor repetitively defines, as a function of the angular orientation of the downreach boom, one of the plurality of individual sensor locations as an on-grade sensor location.

Abstract: An apparatus and method project light in two orthogonal planes to provide reference planes of light for use in laying out a construction site or the like. The apparatus comprises a laser light source for providing a source beam of light, and a light diverting arrangement. The light diverting arrangement diverts a first portion of the source beam of light to project a first thin reference fan beam of light substantially in a first reference plane, and diverts a second portion of the source beam of light to project a second thin reference fan beam of light substantially in a second reference plane. The second reference plane is substantially perpendicular to the first reference plane. The apparatus may advantageously be used in laying out a grid.

Abstract: A laser beam alignment system includes a transmitter which establishes a laser reference plane by continuously rotating a horizontal laser beam about the transmitter. A remotely located receiver senses the elevation of the laser reference plane and reflects a portion of the laser energy back to the transmitter where the reflected energy is employed to produce a signal indicative of the range of the receiver and its location with respect to a reference axis. The position of the receiver is thus established in three dimensions.

Abstract: An apparatus for detecting the relative position and orientation of a reference beam of light includes first and second detectors for detecting the intersection of the reference beam with first and second spaced and substantially parallel reference planes. The measured horizontal and vertical deviations between the points of intersection on the two reference planes provide an indication of the orientation of the beam with respect to the apparatus.

Abstract: Apparatus for projecting a laser beam to provide multiple reference beams includes a beam diverting assembly rotatably mounted at an end of a housing from which emerges a laser beam generated within the housing, and a pentaprism assembly disposed stationarily at the housing end outwardly of the beam diverting assembly. The beam diverting assembly receives the laser beam and splits it into orthogonally-disposed transmitted and reflected beam components. Rotation of the beam diverting assembly about the axis of the transmitted beam component causes rotation of the reflected beam component to define a reference plane. The pentaprism assembly receives the transmitted beam component from the diverting assembly and deflects it to define a stationary reference line disposed in a generally parallel spaced relationship to the reference plane defined by the rotating reflected beam component.

Abstract: A transmitter for an alignment system in which a field of electromagnetic radiation is propagated in a non-planar reference cone is disclosed. The transmitter includes a chassis with a source fixed to the chassis for providing a beam of electromagnetic radiation and an optical deflector which converges toward the source reflects the beam into an omni-directional cone of radiation. A flexible support having an omni-directional stiffness supports the optical deflector in the beam to reflect the reference field in a level orientation when the chassis is level. An angular error in the orientation of the chassis from level results in the optical deflector deviating from the aligned position to maintain the reference field in the level orientation. Damping of the deflector is also provided for and sensors detect when the angular error of the chassis has exceeded an allowable amount.

Abstract: A transmitter for an alignment system in which a field of electromagnetic radiation is propagated in a non-planar reference cone is disclosed. The transmitter includes a source for providing a collimated beam of electromagnetic radiation directed parallel to a beam axis. A cantilever strand supports a bob within the beam. The bob has a conical reflecting surface to reflect the collimated beam conically. Optimally, the cantilever strand and bob are chosen to provide a deflection between the bob and plumb which is substantially one-half of any angular error between the beam axis and plumb. In an especially preferred form, a housing surrounds the bob and has inner and outer surfaces which minimize temperature effects on the orientation of the reference plane. Also, detectors are provided to sense when the angular error between the beam axis and plumb is outside of an acceptable range.

Abstract: An apparatus for projecting a laser beam in a reference plane includes several imrovements. A generally cylindrical, one-piece molded transparent lighthouse structure overlies the rotatable pentaprism beam diverting assembly of the apparatus. The lighthouse structure is mounted on the housing so as to allow transmission therethrough of the rotating laser beam projected by the beam diverting assembly. The lighthouse structure has a tapered or conical configuration facilitating molding thereof, but which produces a divergence of the laser beam as it passes through the structure. A continuous resilient flexible ring is adapted to releasably attach to the apparatus housing and tightly fit about the lighthouse structure for removably anchoring the structure to the housing in a sealed relationship, providing a water-tight enclosure for the pentaprism beam diverting assembly and imposing a generally uniform attaching pressure about the lighthouse structure.

Abstract: A laser beam projection device includes a laser plasma tube assembly having a laser plasma tube and a generally cylindrical casing surrounding the tube. The plasma tube is positioned within the casing such that the beam produced by the tube is aligned with the casing and emerges from the casing through a circular opening at one end thereof. A support frame is provided for mounting the laser plasma tube assembly and also for mounting one or more optical elements in precise alignment with respect to the beam produced by the tube assembly. The frame includes an annular member for engaging the circular opening in the casing in order to align the casing with respect to the frame. The frame further defines a pair of non-parallel alignment surfaces, spaced from the annular member, to contact the outer surface of the casing near the end thereof opposite the circular opening. The casing defines an inner beveled surface surrounding the opening through which the beam emerges.

Abstract: An arrangement for use in a laser beam projection device for controlling the orientation of a support frame upon which a laser beam source is mounted includes a base frame, a support frame, and a pivot for mounting the support frame on the base frame. A level arm is pivotally supported at one point by the support frame and carries a level vial which provides an electrical indication of the orientation of the level arm. A positioning arrangement engages the support frame and the level arm and adjusts their relative position. The positioning arrangement includes a threaded shaft having a first threaded portion engaging the support frame and a nut engaging a second threaded portion of the shaft. The nut contacts the level arm. By rotating the nut, the relative position of the level arm and the support frame are adjusted.

Abstract: A four-way valve for selectively controlling the application of fluid and exhaust pressures to opposite sides of a double acting cylinder utilizes a main valve spool that is axially movable in a valve housing defining ports respectively connected to opposite sides of the cylinder and to the pressured and inlet sides of a fluid pressure source. The spool valve is provided with an axial bore and a pilot spool is mounted in such axial bore. Radial passages are provided in the main valve spool connecting its exterior with the axial bore and external sealing portions on the pilot spool cooperate with the radial port so that in a neutral position of both the main valve spool and the pilot spool, no fluid flow occurs.

Abstract: This invention provides a method for controlling the path of a crop spraying aircraft in making repeated traverses over a field to insure that each traverse is laterally spaced from the adjacent traverse by the proper distance to assure adequate coverage of the crop land with the material being sprayed and avoiding over-lapping or insufficient coverage of any portion of the crop land. In accordance with the method of the invention, the crop spraying aircraft carries a rotating laser beam transmitter and receiver, and the transmitted beam is reflected from a plurality of reflectors located on the ground at known positions relative to each other to provide successive reflections of the transmitted laser beam from which the angular positions of the aircraft relative to the reflectors may be continuously determined.

Abstract: In a backhoe of the type having an outreach boom horizontally pivotally mounted relative to a vehicle and an hydraulic cylinder therebetween, a downreach boom horizontally pivotally mounted on the free end of the outreach boom and an hydraulic cylinder therebetween, and a digging bucket horizontally pivotally mounted on the free end of the downreach boom and an hydraulic cylinder therebetween, apparatus is provided for respectively generating signals proportional to the angle between the outreach boom and the horizontal, the angle between the outreach boom and the downreach boom, the angle between the downreach boom and a line drawn to the digging teeth of the bucket, and an angle equal to the desired slope of the bottom of the excavation relative to the true horizontal.

Abstract: The invention relates to a digging bucket for a backhoe or similar excavating machine, wherein the effective forward digging edge of the bucket may selectively comprise a transverse row of digging teeth for use in the primary phases of an excavation or a blade-type edge used for smoothing the bottom of the excavation. The backhoe bucket structure permitting this instantaneous choice by the operator comprises a conventional bucket having digging teeth secured thereto to the forward edge of the bottom but the medial portion of the bottom of the bucket is movably mounted relative to the remainder of the bucket so that the forward edge of the movable bottom portion can be dropped to a position below the digging teeth to function as a smoothing blade.

Abstract: The cutting depth of an endless chain type trencher is normally determined by the angle of the frame carrying the endless chain relative to the horizontal. In accordance with this invention, the angular position of the digging frame, hence the depth of the trench is controlled by the angular relationship of a trailing shoe carried by the digging frame relative to the digging frame. The trailing shoe has an elongated horizontal bottom surface that normally rides along the bottom of the formed trench. An upstanding mast is secured to the shoe at a point forwardly of the bottom surface and means on the top of the mast are utilized to indicate and control the depth of the trench.

Abstract: The cutting depth of an endless chain type trencher is normally determined by the angle of the frame carrying the endless chain relative to the horizontal. In accordance with this invention, the angular position of the digging frame is controlled by one or more hydraulic cylinders which, in turn, are controlled by signals derived from sensors carried by an upstanding vertical mast mounted to the frame which detects a reference plane defined by a rotating laser beam. A trigonometric correction factor to compensate for the mast mounting is included.

Abstract: The invention relates to a mechanism permitting the manual control of an trencher which is normally carried in trailing relationship to a vehicle and is pivotally mounted to the vehicle. The effective cutting depth of this type trencher is determined by the angle of the frame carrying the endless chain relative to the horizontal. An upstanding sighting bar is pivotally mounted to the frame of the trencher and means are provided for maintaining the sighting bar in a true vertical position irrespective of the angle of the frame relative to the horizontal. Additionally, the effective vertical height of the sighting bar is varied as a trigonometric function of the angle of the digging frame relative to the horizontal.