Abstract: A system for testing at least one test piece. The system includes a pressure vessel including a first chamber receiving a first fluid at a first pressure. The pressure vessel further includes a second chamber receiving a second fluid. The pressure vessel further includes an actuating membrane fluidly separating the first chamber from the second chamber. The system further includes a test vessel including an internal chamber disposed in fluid communication with the second chamber. The test vessel further includes at least one test wall coupled to the at least one test piece. The system further includes an actuator engaged with the actuating membrane and configured to apply a time-varying force on the actuating membrane while the first pressure is being applied by the first fluid on the actuating membrane.

Abstract: This invention relates to a method of controlling torque oscillations in a mechanical drive train of an electrical generation system which provides electrical power to an isolated electrical network, the method including the steps of: a. monitoring for changes in the electrical condition of the electrical network; b. determining whether a change in the electrical condition of the network falls within a predetermined range; c. adjusting the power in the network using an auxiliary power source when the electrical condition of the network falls within the predetermined range so as reduce or substantially prevent the build up of torque oscillations in the mechanical drive train.

Abstract: This invention relates to a method of controlling torque oscillations in a mechanical drive train of an electrical generation system which provides electrical power to an isolated electrical network, the method including the steps of: a. monitoring for changes in the electrical condition of the electrical network; b. determining whether a change in the electrical condition of the network falls within a predetermined range; c. adjusting the power in the network using an auxiliary power source when the electrical condition of the network falls within the predetermined range so as reduce or substantially prevent the build up of torque oscillations in the mechanical drive train.

Abstract: An apparatus for providing percussion action in a rotary power tool having a rotary output shaft, the apparatus comprising at least one moveable mass adapted to have a component of movement parallel to the axis of the rotary output shaft to cause impacts to be applied to a working member of the tool; and a device for intermittently converting rotary movement of the rotary output shaft into movement of at least one the moveable mass to cause the impacts to be applied to the working member.

Abstract: An apparatus for providing percussion action in a rotary power tool having a rotary output shaft, the apparatus comprising at least one moveable mass adapted to have a component of movement parallel to the axis of the rotary output shaft to cause impacts to be applied to a working member of the tool; and conversion means for intermittently converting rotary movement of the rotary output shaft into movement of at least one the moveable mass to cause the impacts to be applied to the working member.