Abstract: A membrane tension measuring apparatus comprises: a rectangular frame (5) adapted to be abuttable on a surface (4) of a membrane (2) to which tension (Tx, Ty) is applied; an acoustic wave generator (17) operable to emit an acoustic wave (16) toward a part (2a) of the membrane (2) surrounded by the frame (5); a vibration detector (24) operable to detect vibration which is induced in the part (2a) of the membrane (2) by the emitted acoustic wave (16); and a processor (29) operable to calculate the tension (Tx, Ty) based on vibration data detected by the vibration detector (24). Each of the acoustic wave generator (17), the vibration detector (24) and the processor (29) is mounted to the frame (5).

Abstract: A membrane tension measuring apparatus comprises: a rectangular frame (5) adapted to be abuttable on a surface (4) of a membrane (2) to which tension (Tx, Ty) is applied; an acoustic wave generator (17) operable to emit an acoustic wave (16) toward a part (2a) of the membrane (2) surrounded by the frame (5); a vibration detector (24) operable to detect vibration which is induced in the part (2a) of the membrane (2) by the emitted acoustic wave (16); and a processor (29) operable to calculate the tension (Tx, Ty) based on vibration data detected by the vibration detector (24). Each of the acoustic wave generator (17), the vibration detector (24) and the processor (29) is mounted to the frame (5).

Abstract: In a flexible container, there is provided three or more approximately rectangular main sheets, and a rectangular inlet sheet and outlet sheet are provided on an imaginary line passing through approximately the central part in the width direction of each of the main sheets. One end of each of the inlet sheet and the outlet sheet in the direction along the imaginary line is sewed to an end of the main street corresponding to the one end, and the other end of each of the inlet sheet and the outlet sheet is projected away from the main sheet in the direction along the imaginary line. The imaginary lines of assembly sheets each constituted by the three types of sheets conform to one another, opposed surfaces of the adjacent assembly sheets are joined to each other, and outer side edges of the adjacent assembly sheets are sewed together.

Abstract: In a flexible container, there is provided three or more approximately rectangular main sheets, and a rectangular inlet sheet and outlet sheet are provided on an imaginary line passing through approximately the central part in the width direction of each of the main sheets. One end of each of the inlet sheet and the outlet sheet in the direction along the imaginary line is sewed to an end of the main sheet corresponding to the one end, and the other end of each of the inlet sheet and the outlet sheet is projected away from the main sheet in the direction along the imaginary line. The imaginary lines of assembly sheets each constituted by the three types of sheets conform to one another, opposed surfaces of the adjacent assembly sheets are joined to each other, and outer side edges of the adjacent assembly sheets are sewed together.

Abstract: A sail device characterized in that a sail frame is formed of upper and lower horizontal beam members fixed horizontally to a mast and linealy bent at bending points, holding pillars that are rotatably supported at the above mentioned bending points by these horizontal beam members and that hold a part of a developed sail, and supporting pillars arranged and fixed at both right and left ends of the above mentioned horizontal beam members and assembled rotatably with respect to the horizontal beam members and rotation stoppably by stopper means,at least, between the above mentioned upper and lower horizontal beam members, the lower horizontal beam member is formed to be of a horizontally expanding shape,a sail formed of a flexible material is reinforced by fitting a plurality of self-standing rods in the vertical direction of the sail and the above mentioned self-standing rods can be supported at the lower ends on the above mentioned lower horizontal beam member.