Abstract: A target for use with a laser generating device is disclosed which diffracts a reference laser beam of light directed to the target along an optical axis of the target to provide a diffracted beam of light offset from the optical axis which is more easily visible to a detector, such as a human eye. Preferably, the diffracted beam includes at least one lobe offset from the optical axis at least 40° and, further, is diffracted in a multi-lobe pattern. For example, the target body may include diffractive bodies either in the substrate forming the body or on a carrier member which is mounted to the target body. The diffractive bodies are dimensioned on the same order of magnitude as the wavelength of the light of the reference laser beam of light. Preferably, the diffractive bodies have a diameter in a range of approximately 0.1 microns to 5.0 microns, more preferably, 0.1 microns to 2.0 microns and, most preferably, 0.5 microns to 1.0 microns.

Abstract: A control system for establishing grade and elevation control for a tool of a construction apparatus for maintaining the vertical position of the tool relative to a reference includes a first ultrasonic transducer configured to be carried by the construction apparatus, with the first transducer transmitting and receiving acoustic waves, at least one reflector, a second ultrasonic transducer configured to be carried by the construction apparatus, with the second transducer receiving acoustic waves, and a controller coupled to the first and second ultrasonic transducers which drive the transducers to produce an acoustic wave and monitors the time reflections of the acoustic wave are respectively received by the first and second transducers.

Abstract: A laser system comprising a laser transmitter and a laser receiver is operable to adjust the laser beam or the laser plane generated by the laser transmitter in response to one or more inputs by a user of the system. The system is operable in one or more modes, such that communication from the laser receiver to the laser transmitter results in various adjustments to the laser beam or tilt or slope of the plane generated by the beam. The present invention is preferably operable to automatically account for any drift in the system, or to adjust the slope of the plane generated by the transmitter in response to a detected location of the laser receiver. Additionally, the laser transmitter may be operable to automatically oscillate the beam in a given area in response to detection of the laser receiver in that area. Each of these modes may be actuated via a simple user input at the laser receiver and/or the laser transmitter.

Abstract: A rotating laser beam projector includes a power controller having a micro controller coupled to a laser power circuit which determines whether the laser beam emitted by the projector is rotating or stationary. When the laser beam is rotating, the laser power circuit delivers a first level of continuance power to the laser. When the laser beam is stationary, the laser power circuit delivers a second level of continuance power to the laser which is less than the first level of power. The micro controller communicates messages from the laser beam projector to a remotely positioned sensor assembly by rotating the laser beam at a first speed when no message is to be communicated and rotating the laser beam at a second speed, different from the first speed, when a message is to be communicated. The laser beam projector includes a bridge for delivering electrical power to a pendulum-supported device from a stationary source.

Abstract: A control system for establishing grade and elevation control for a tool of a construction apparatus for maintaining the vertical position of the tool relative to a reference includes a first ultrasonic transducer configured to be carried by the construction apparatus, with the first transducer transmitting and receiving acoustic waves, at least one reflector, a second ultrasonic transducer configured to be carried by the construction apparatus, with the second transducer receiving acoustic waves, and a controller coupled to the first and second ultrasonic transducers which drive the transducers to produce an acoustic wave and monitors the time reflections of the acoustic wave are respectively received by the first and second transducers.

Abstract: An apparatus and method for controlling a hydraulically operated construction machine having a plurality of tandem articulated members which move in a particular pattern, wherein movement of one of the articulated members is controlled in response to movement of a second one of the articulated members. Anticipated future movement of the second articulated member is determined and the first articulated member is controlled as a function at least of the anticipated future movement of the second articulated member. Anticipated future movement is determined by measuring actual delay between movement of the first and second articulated members. Operation of the articulated members is a function of operation of an actuator and a selectable command level.

Abstract: A rotating laser beam projector includes a power controller having a micro controller coupled to a laser power circuit which determines whether the laser beam emitted by the projector is rotating or stationary. When the laser beam is rotating, the laser power circuit delivers a first level of continuance power to the laser. When the laser beam is stationary, the laser power circuit delivers a second level of continuance power to the laser which is less than the first level of power. The micro controller communicates messages from the laser beam projector to a remotely positioned sensor assembly by rotating the laser beam at a first speed when no message is to be communicated and rotating the laser beam at a second speed, different from the first speed, when a message is to be communicated. The laser beam projector includes a bridge for delivering electrical power to a pendulum-supported device from a stationary source.

Abstract: A digitally filtered laser receiver includes a plurality of radiation sensors spacially arranged in a manner which identifies a relative position of the sensors with respect to a rotating laser radiation source. The digitally filtered laser receiver includes a microcomputer having inputs which are responsive to impingement of the sensors by radiation. The microcomputer is programmed to process data from the inputs only when the radiation sensors are impinged by radiation from the rotating laser radiation source. The microcomputer processes the data and provides an output which is indicative of the position of the rotating laser radiation source and the sensors.

Abstract: A method and apparatus for demolishing a structure is disclosed. A crusher member (12) is provided supported by a support frame (14). A reference position vertically above an operator is established. The relative distance between the crusher member (12) and the reference position in a generally vertical direction is monitored. The crusher member (12) is guided to the reference position as a function of the relative distance in order to prepare for a demolition cycle of removing a portion of the structure. The crusher member (12) is then manually manipulated through a demolition cycle.

Abstract: A self-levelling laser generator apparatus (10) includes a housing (12), a light source in the housing which produces a beam of collimated light, and a self-levelling mechanism (18). The self-levelling mechanism includes an electronically controllable signal source, such as a digital potentiometer (46), which is provided a command (44a-44c) from a programmed computer (38) to produce a controllable output (48). The output of (48) the digital potentiometer is summed by a summing circuit (34) with the output (28) of an inclination sensor (24) in order to produce a compensated inclination signal (36) which is provided as an input to computer 38. The computer additionally receives a calibration input (20, 21) indicative of deviation between the inclination of the laser beam and a predetermined grade. The computer produces a drive signal (50a, 50b) for the self-levelling mechanism (52, 54) that is a function of the compensation inclination signal.

Abstract: A method and apparatus for aligning individual sections of pipe includes directing a beam of collimated light in the general direction of the pipeline and scanning the beam laterally. A target, having a retro reflective portion, is positioned in a location that will be traversed by the scanning beam. A reflection of the beam produced by the reflective portion is received and processed. The scanning is discontinued when the reflective portion is located and the beam is aimed in a direction related to the position of the retro reflective target.

Abstract: An apparatus and method for controlling a hydraulically operated construction machine, having a plurality of tandem articulated members which are controlled in a manner that movement of one of the members is controlled in response to movement of another of the members, in order to move the members in a predetermined pattern. The members are controlled in response to the anticipated future movement of the another member. Anticipated future movement of the another member may be determined, for example, as a function of the present position and velocity of the another member and system delay in movement of the another member. Where the another member is controlled manually by an operator control lever coupled with a manual hydraulic control valve, anticipated future movement may be determined by monitoring actuation of the control lever.

Abstract: A method and apparatus for controlling a trencher having a tractor that is propelled along terrain and a trenching implement adjustably mounted to the tractor at a rearward portion thereof with respect to movement of the tractor along the terrain includes monitoring movement of the tractor as it is propelled along terrain in order to survey the contour of the terrain and adjusting the position of the trenching implement with respect to the tractor as a function of the contour of the terrain in the vicinity of the trencher.

Abstract: An ultrasonic sensor for a construction implement is disclosed which provides an indication of the position of the sensor relative to a reference surface in two dimensions. In a preferred embodiment of the invention, a pair of sensors are positioned a predetermined distance from one another to transmit and receive ultrasonic waves to measure the time it takes the waves to travel to the reference surface and be reflected back to the ultrasonic transducers. Additionally, a transducer is disclosed which detects a side lobe of a acoustic wave transmitted by an acoustic transducer whereby the velocity of said acoustic pulse may be calculated.

Abstract: An ultrasonic sensor for a construction implement is disclosed which provides an indication of the position of the sensor relative to a reference surface in two dimensions. In a preferred embodiment of the invention, a pair of sensors are positioned a predetermined distance from one another to transmit and receive ultrasonic waves to measure the time it takes the waves to travel to the reference surface and be reflected back to the ultrasonic transducers. Additionally, a transducer is disclosed which detects a side lobe of a acoustic wave transmitted by an acoustic transducer whereby the velocity of said acoustic pulse may be calculated.

Abstract: A compact laser construction instrument intended for use by the average construction contractor. The instrument is capable of generating a rotating plane of laser light and a beam of light that is perpendicular to the rotating plane. It includes a beam generator adapted to generate a beam of collimated light along a given axis. A rotating platform is provided for supporting the beam generator for rotation in a plane parallel the axis of the collimated light and about a rotation axis that is perpendicular to the axis of the collimated light in order to generate a plane of light. A means is provided that is positioned for rotation with the platform for generating a second beam of collimated light along the rotation axis to generate a rotating narrow beam of light that is perpendicular to the plane.

Abstract: A surveying instrument is provided which includes an optical sighting scope having a sighting barrel and orthogonal reticular lines visible to an observer viewing through the barrel, in combination with a miniature light plane generator that is oriented to produce a plane of light that is coincident with one of the reticular lines in the direction viewed by an observer viewing through the barrel of the optical sighting scope. The miniature light plane generator includes a laser diode that generates a beam of light, a collimating lens positioned within the beam of light generated by the laser diode in order to produce a beam of collimated light, and a fan lens positioned within the beam of collimated light in order to divert the beam of light into a plane. The miniature generator additionally includes a power supply that supplyies power at a low duty cycle.

Abstract: A control for an excavator controls the position of the bucket cutting edge to a desired depth accurately by a calibrating laser receiver mounted on the excavator stick member and passed through a stationary laser plane wherever the stick is moved into or out of a trench. Linear position encoders monitor the length that the actuating cylinders are extended and lookup tables convert the encoder outputs to angle representations for determining the positions of the laser receiver and the cutting edge. Other lookup tables are utilized to avoid time-consuming iterative calculation procedures to provide real-time digital process solutions of trigonometric functions. The apparatus includes a unique laser receiver comprising a plurlaity of linearly aligned photo receptors with associated circuitry for producing an output representative of the receptor illuminated or, if a group of receptors are illuminated, the centermost receptor illuminated.

Abstract: A laser-actuated depth sensor for an excavator, including a laser receiver, an inclination sensor assembly and indicators to inform the operator of the position and inclination of the excavator stick, is completely self-contained in a housing that may be mounted to the stick of an excavator. The indicators, which are each an array of LEDs, and corresponding indicia are readily visible to the operator who does not have to take his or her eyes off the excavation work zone.