Abstract: A sewing machine includes a needle bar, a needle bar up-and-down movement mechanism, a swinging mechanism, a lower shaft, an outer shuttle, a thread cutting mechanism, a rotation speed adjustment mechanism, and an actuator. The needle bar up-and-down movement mechanism is configured to move the needle bar up and down. The swinging mechanism is configured to swing the needle bar in a left-right direction. The lower shaft is configured to rotate in synchronization with up-down movement of the needle bar. The outer shuttle is configured to rotate along with rotation of the lower shaft. The thread cutting mechanism is configured to cut at least an upper thread. The rotation speed adjustment mechanism is configured to adjust a rotation speed of the outer shuttle. The actuator is a driving source of the thread cutting mechanism and the rotation speed adjustment mechanism.

Abstract: A cylinder containing a piston rod to which a nozzle is attached, is fixed to the outside of a tank. A pressurized fluid is sprayed into the tank from the nozzle, and the piston rod elongates and contracts with the pressure of this fluid. Further provided are a first supply passage connecting a first pressure chamber formed around the piston rod in the cylinder to a pump, a return passage connecting a second pressure chamber on the opposite side of the piston rod to the tank, and a second supply passage connecting the second pressure chamber to the pump. A first valve is provided in the return passage, and a second valve is provided in the second supply passage.

Abstract: In a mineral mining installation employing a series of shifting rams for advancing a scraper-chain conveyor provided with a guide for a mining machine a control system with a central control station for transmitting control signals. The control signals serve to actuate local control valves, possibly in time dependence, to cause a selected one or group of metering devices to transfer a pre-determined volume of pressure fluid to one or more of the rams to effect said advancement. This volume of pressure fluid is some fraction of the total capacity of the ram or rams in question so that by repeatedly transmitting control signals the device or devices can perform successive cycles of operation to thereby cause the ram or rams associated therewith to extend in defined increments.