Abstract: A piezo-electric actuator operated press in which piezo-electric actuators are employed as punch driving sources, and, with a workpiece held between an upper and lower die set, the punches are driven by the piezo-electric actuators to punch the workpiece; the punches and the piezo-electric actuators are built in the respective die sets, and the movable one of the die sets is coupled to a die shifting mechanism, so that it is driven to a die opening position or a die closing position, whereby the workpiece can be smoothly fed in and taken out of the press.

Abstract: In blanking a metal foil on a press comprising a pair of dies, a pair of punches, and a pair of piezoelectric actuators for driving the punches with are all arranged above and below the metal foil, the punches are vertically vibrated by the piezoelectric actuators, so that, while the punches being held abutted against both surfaces of the metal foil clamped between the dies, a half blanking operation and a reverse blanking operation are carried out alternately, whereby the metal foil is cut along the shearing surface through low cyclic fatigue without formation of burrs.

Abstract: A piezo-electric actuator, comprising a flat spring having a plurality of arched side beams, the arched side beams having first and second ends, a central beam having first and second ends and top and bottom surfaces and disposed between the arched side beams, a fixed first end portion connecting the first end of the central beam with the first ends of the plurality of arched side beams, and a free second end portion connecting the second ends of the central beam with the second ends of the plurality of second arched side beams, wherein the arched side beams and the central beam are parallel to each other, and a piezo-electric element affixed to the bottom surface the central beam.

Abstract: A photoelectric conversion-type rotational position indicator for indicating the rotational position of a rotating body, including a light receiving member having one or more identically shaped light receiving portions made from a photoelectric converting material at predetermined spacings on the light receiving member to generate sinusoidal signals out of phase from each other, and a light shielding member operably connected to the rotating body such that the light shielding member rotates with the rotating body, the light shielding member having windows shaped with an inner curve and an outer curve such that the visible area of each light receiving portion through each of the windows varies in a sinusoidal form of one cycle as the light shielding member rotates, and means for obtaining the phased separated sinusoidal signals by connecting groups of light receiving portions in parallel or series.