Abstract: A method and apparatus to cancel gear vibration and noise by imposing a canceling drive torque or force on a driven gear set. Sensors receive information and produce an error signal representative of the vibration and/or noise generated at meshing gears. The error signal indicative of vibration and/or noise information is provided to a control mechanism that processes the noise information to generate a corresponding drive torque. The drive torque corresponding to the noise information is applied to a drive shaft or through a power supply to reduce vibration and noise of the gear assembly at gear meshing frequencies.

Abstract: A method and apparatus for, in an optical data recorder, focusing a recording light beam on a recording medium. In the apparatus, an optical head has focusing means movable in a direction perpendicular to the recording medium for changing the focus position of the recording light beam on the recording medium.

Abstract: A method and apparatus for, in an optical data recorder, maintaining a recording light beam in an on-track position on a recording medium. In the apparatus an optical head has a tracking arrangement movable in a direction parallel to the recording medium for changing the tracking position of the recording light beam on the recording medium.

Abstract: Track jumping in the present system is accomplished by using a two step track jump method which accelerates the tracking actuator toward the desired track at maximum acceleration and then decelerates the tracking actuator at a maximum deceleration so that the desired track is reached in a minimum amount of time without the actuator ringing. A matrix containing the times for each jump pulse from track X to track Y is recorded. The matrix table is updated after each jump to compensate for variance factors. The table is stored in memory which allows the system to become more accurate with each jump. If the actuator falls short of the desired position, the jump pulse next applied is lengthened slightly. If the jump pulse causes the actuator to overshoot, the desired position the jump pulse is shortened for the next jump.

Abstract: The present method operates upon an optical disk type servo-system of the type having an optical tracking servo for maintaining a lens centered over a track on a disk and a tracking position servo for moving an optical head's lens to a desired position. Included within such a system is an eccentricity sub-system for providing a compensating sine wave signal for reducing errors in tracking due to disk decentering. The present method automatically adjusts the gain in one of the servos to match the gain appearing in the other servo so as to improve the smoothness of control when switching between the servos.

Abstract: A focus acquisition servo system and method which speeds the acquisition process by focusing on the recording media of an optical disk while the disk is coming up to speed. Focus is accomplished by jumping the focus actuator from a start position close to the focus position and by ramping the focus actuator away from the surface of the disk while monitoring focus gain. When the focus gain reaches a peak amplitude the disk is in rough focus, ramping is stopped and the focus servo system is activated to lock the focus actuator onto a fine focus on the disk's recording media.

Abstract: An improved pavement extractor is disclosed herein which comprises a completely self-contained unit for removal of pavement in a situation where a new pavement is to be created. The device includes a combination of rippers and a hold-down pressure plate which efficiently extracts the pavement from the sub-base, a control chamber where the extracted pavement is led from the rippers and the hold-down pressure plate, which control chamber has located therein a pair of opposed rollers which controllably hold the pavement while a beater mechanism beats off pieces of the pavement of predetermined adjustable size. From the beater mechanism, the extracted pavement is conveyed to an elevator mechanism included in the device which conveys the now beaten small size pieces of pavement up to a sufficiently high level so as to enable the loading thereof into a vehicle such as a dump truck.

Abstract: The present invention relates to a rock extractor apparatus and method of using the rock extractor for removing rocks embedded in the ground and/or for removing rocks partially embedded in the ground. The invention is particularly directed to removing rocks from soil suitable for farming. The rock extractor consists essentially of a digger unit, a grate unit and a conveyor unit, all of which cooperate to efficiently and effectively extract rocks from the soil and to render the soil suitable for cultivation. The rock extractor is attached to a draft machine such as a tractor and pulled through the soil.The tractor pulling the extractor through the soil causes rock and soil to be dug up and moved over the digger unit. The grate unit and conveyor unit cooperate to forcefully drive the conveyor unit downwardly and forwardly into the pile of rock and soil that is moved from the digger unit onto the grate unit and to rapidly move the rock and soil rearwardly along the grate unit.