Abstract: A circuit arrangement including a computer is built in an electrical jig saw where various data or information, such as the sort of the material of the workpiece, the thickness of the workpiece, desired degree of finish and way of cutting, are manually inputted via a keyboard so that the computer selects and determines optimum working condition, such as the sort of blade to be used, the locus of the blade, blade strokes per minute which is in proportion to the motor speed, and the necessity of application of coolant oil. The circuit arrangement also comprises circuitry for automatically controlling the rotational speed of the motor of the jig saw so that an actual speed of the blade equals a desired speed represented by strokes per minute. A display unit is coupled with the computer for indicating input and output data of the computer for supplying visual information to the user of the jig saw.

Abstract: In an electrical tool having a clutch for adjusting rotational torque of the driven shaft, a limit switch of double-throw type is used for detecting the state of the clutch, and a capacitor is arranged to be charged via the limit switch. In one embodiment of the instant invention, the capacitor is normally discharged and is charged when the clutch assumes a disengaged state, thereby producing a trigger pulse used for making a short circuit for the motor only when the capacitor is not fully charged. In another embodiment, the capacitor is normally charged, and is discharged when the clutch assumes a disengaged state, thereby producing a trigger pulse used for making a short circuit for the motor. With this arrangement a switching circuit provided for making the short circuit for the motor is effectively prevented from making the short circuit when a power switch is turned on irrespective of the state of the clutch.

Abstract: A flow divider valve assembly for dividing a flow of fluid between a priority flow device, such as a power steering system, and an excess flow device, such as an auxiliary mechanism. The flow divider valve assembly comprises a valve body defining an inlet port to be connected to a source of fluid under pressure, a priority flow outlet port, an excess flow outlet port and a valve bore interconnecting the ports, and a valve spool axially movable within the valve bore, the valve spool having formed therein an axial bore for permitting a constant communication between the inlet port and the priority flow outlet port. A first restrictor is disposed between the inlet port and the priority flow outlet port and a second restrictor is disposed between the inlet port and the excess flow outlet port. Restriction rate of the first restrictor is made larger than that of the first restrictor.