Abstract: It is an object of the invention to provide a simple and small slide-falling preventing apparatus capable of reliably preventing a slide from falling within a short time in an arbitrary slide position without slight falling of the slide, and capable of being additionally mounted to an existing press machine with small modification within a short time while securing excellent maintainability. The slide-falling preventing apparatus comprises an external tooth gear of a rotating and driving system of a slide, an external tooth gear mounted on a rotation shaft of a rotating and driving system of a slide or an external tooth gear which meshes with a tooth gear of a rotating and driving system of a slide.

Abstract: First left and right channel loudspeakers having respective main axes of directivities directed toward left and right listening areas defined in front thereof are provided. In addition, there are provided a second right channel loudspeaker near the first right channel loudspeaker with a main axis of directivity directed toward the left listening area, a second left channel loudspeaker near the first left channel loudspeaker with a main axis of directivity directed toward the right listening area, and signal adjusting means for controlling the relative amplitude and time difference among the signals to be supplied to these loudspeakers.