Abstract: An electrically dimmable window (“EDW”) system comprising an EDW, a control switch, and a controller. The switch and controller control the light transmittance level of the EDW. State indicators indicate when the EDW is in transition from one light transmittance level to another level. When there is no transition in light transmittance level, the indicators may denote the current light transmittance level of the EDW.

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.

Abstract: A control for an excavator controls the position of the bucket cutting edge to a desired depth accurately by a calibrating laser receiving 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 plurality 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 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 plurality 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 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 plurality 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 vent apparatus for controlling the flow of heated exhaust air from a clothes dryer has a housing connected to the heated exhaust conduit and a filter within the housing for filtering the exhaust gases. Controls regulate the relative amounts of exhaust gases directed outside the dryer room and through the housing into the dryer room. In one embodiment, the heated dryer air is ducted through the housing and the control is a valve which directs the gas either into the housing or through the exhaust outlet of the housing. The invention channels moist, heated air into a house in desired proportions to conserve heat energy and to humidify the home in the winter.

Abstract: A reference light beam projector of the type which produces a modulated plane of light for use as a reference in many different applications such as for aligning railroad tracks. This modulated reference plane is formed by projecting a collimated light beam along a predetermined path and providing means for variably refracting the beam so to effectively variably bend the beam back and forth along a plane. Specifically, the means for variably refracting the beam is a rotating optical element comprising a window through which the beam is transmitted and variably refracted as the optical element is rotated.

Abstract: Self-leveling light beam projection apparatus for projecting and maintaining a beam of light along a predetermined path relative to the earth's vertical. A housing adapted for mounting in a predetermined plane includes a light source such as a laser generator for generating a collimated beam of light. A lens system including a pendulum mounting at least one lens is mounted for movement about mutually perpendicular axes to seek the vertical and to maintain the projected beam along the predetermined path despite the relative positions of the housing and light source.