Abstract: This invention relates to a chuck device with multistage degree of opening composed of an oscillating actuator acting as a driving part and an arm opening or closing mechanism installed at one end part to which an output shaft of the oscillating actuator is projected, the actuator having a plurality of oscillating vanes concentrically arranged within casings, the casing for an inner oscillating vane structure being rotatably supported in respect to the casing for an outer oscillating vane structure so as to form a rotary shaft and at the same time an oscillating vane of the outer oscillating structure is fixed to the rotary shaft.

Abstract: In an MONOS type nonvolatile semiconductor memory comprising a channel forming semiconductor region between source and drain regions in a surface of a substrate; a tunnel insulating film formed on the channel forming semiconductor region in the surface of the substrate, the tunnel insulating film permitting charge-injection; a silicon nitride film formed as a second insulating film on the tunnel insulating film; a silicon oxide film formed as a third insulating film; and a conductive electrode formed on the silicon oxide film, the silicon nitride film has a composition close to a stoichiometric value of Si.sub.3 N.sub.4 at a portion near an interface with the tunnel insulating film and has a composition of excess silicon at a portion of the thickness of the same film except near the interface with the tunnel insulating film.

Abstract: An air pressure shock absorber for smoothly stopping a moving object reciprocated by a rod in an air pressure cylinder. The shock absorber absorbs and reduces the internal pressure of a chamber in the cylinder to smoothly stop the moving object by the communication of air compressed in the chamber to the atmosphere through a bypass passage formed in a cylinder wall. The air pressure is released to the atmosphere after the piston has moved through a predetermined stroke.

Abstract: An air pressure shock absorber for smoothly stopping a moving object reciprocated by a rod in an air pressure cylinder. The shock absorber absorbs and reduces the internal pressure of a chamber in the cylinder to smoothly stop the moving object by the communication of air compressed in the chamber to the atmosphere through a bypass passage formed in a cylinder wall. The air pressure is released to the atmosphere after the piston has moved through a predetermined stroke.