Abstract: A method and apparatus for applying a foamed mixture of paints on a structural surface. A continuous stream of high velocity gas moves through a nozzle and is directed toward the structural surface, and two or more paints may be intermittently moved into the gas stream of the nozzle and aerated and mixed with each other and moved with the gas stream to form a foam that is applied to the structural surface. The components of the foamed mixture may include single component or plural component materials such as polyurethane foam, adhesive, and polyurea formulations, and may be moved through a volumetric metering device consisting of material heaters, a heated hose, and an applicator gun. The nitrogen gas stream fluidizes the mixture as it passes through and out of the nozzle and forms the mixture into a foam that is applied to the structural surface.

Abstract: A method and apparatus to commutate the drive voltages of a brushless DC motor. The present invention determines rotor position and velocity by detecting the polarity reversal of the Back-EMF of an undriven leg when compared to a transformed pseudo-reference. In an extra measure of efficiency, the present invention is independent of hardware sensors; it includes a commutation delay timing circuit for optimization of motor operation, and it minimizes the participation of a microprocessor or other microcontroller.

Abstract: A method for starting a sensorless brushless DC motor. The present invention uses the physical equations of motion of the motor to calculate commutation advancement rates during the motor's start-up period. An algorithm initially calculates the commutation advancement rates for the motor's maximum theoretical accelleration. The commutation applied to the motor is advanced through a predetermined number of commutation states using these maximum rates. After the predetermined number of commutation states have been applied, the speed of the motor is checked to determine whether the motor is spinning at a high enough speed to permit use of the motor's normal commutation state advancement system. If the motor is not up to speed, the rate at which the commutation states are advanced is incrementally decreased until satisfactory operation of the motor is obtained or until motor failure is diagnosed and starting is aborted.

Abstract: A method and apparatus to commutate the drive voltages of a brushless DC motor. The present invention determines rotor position and velocity by detecting the polarity reversal of the Back-EMF of an undriven leg when compared to a transformed pseudo-reference. In an extra measure of efficiency, the present invention is independent of hardware sensors; it includes a commutation delay timing circuit for optimization of motor operation, and it minimizes the participation of a microprocessor or other microcontroller.

Abstract: Positioning apparatus for moving read-write transducers in data record systems achieves improved stability in the motion and positioning of such transducers with reduced complexity of structure compared with known apparatus of the prior art. A particular structure, including a female dovetail guide surface and a plurality of cooperating sloped guide wheels, one of which is spring-loaded for force balancing, causes a plurality of reference guide wheels to maintain firm and stable contact with a smooth and flat reference surface and assures the desired stable and accurate movement of the carriage.