Abstract: A vibrating cutting tool capable of making uniform micro-vibrations at the cutter edge generated during machining. The vibrations at the cutter edge are transmitted to balls biassed by springs, compressing the springs. The vibrations are transmitted from the balls through the output shaft back to the cutter edge. While the cutting force is small, the amplitude of vibration of balls is relatively large. When it increases, the holder acts on the balls more than the spring does so that vibration is suppressed. As a result, the amplitude of vibration becomes uniform.

Abstract: A control device for an air hoist drives an air motor rotated by an air supply. The air hoist lifts or lowers a load by rotating a chain wheel. When the chain wheel rotates to lower the load, a small amount of air is supplied to the air motor in order to drive it in the normal lifting direction so that the braking force generated by the motor may reduce the load lowering speed and may gradually lower the load utilizing its own weight. Also, a mechanism for restraining the rotation in the normal lifting direction, when the chain wheel is under slow speed control, is actuated to restrain the rotation of the air motor, thereby stopping the chain wheel in a safe and sure manner without using a mechanical brake.

Abstract: The invention relates to a control apparatus for a pneumatic impact wrench driven by an air motor.

Abstract: A pneumatic impact wrench. This device is characterized in the improvement of the torque controlling mechanism incorporated therein, said mechanism comprising a torsion bar, a spindle case, a fluid element, and valves, holes and passages all functioning in close linkage with each other thereby enabling execution of the torque control and even change of the torque control value precisely. In this mechanism, an air motor driving this device is brought to a halt automatically as the result of closing of a main valve in relation to the operation of said fluid element, said operation of said fluid element being available from air pressure change caused by the closing or narrowing of an air exhausting hole taking place in compliance with twisting of said torsion bar under its partially rolling effect at the rear portion thereof, said torsion bar fixing to said spindle case at their forward portions at this time being imparted with a rotation-suspending resistance thereto at their fixing portion.