Abstract: A pendulum member swings right and left relative to an air compressor remaining still in a fixed position. As a result, the air compressor slides relative to and from end to end of a piston chamber of the pendulum member. The air compressor compresses air in a portion of the piston chamber forward with respect to a sliding direction of the air compressor, and decompresses air in a portion of the piston chamber rearward with respect to the sliding direction. This action is repeated continuously whereby compressed air in the forward portion of the piston chamber flows through a wind turbine chamber to the rearward portion of the piston chamber. The series of air flows forcibly and continuously rotates a wind turbine, which in turn rotates a generator to obtain electricity.

Abstract: A vacuum airtight container is provided in which the air left inside an inner container can be discharged by pushing and pulling the inner container and an outer container with respect to each other, and a production cost can be reduced. In order to attain the object, the inner container in which a second check valve is disposed in a bottom portion is slidably inserted into an inner cylindrical portion of the outer container in which a first check valve is disposed in a bottom portion via a V-shaped O-ring as a sealing member. A cover member is screw fastened to an upper end opening portion of the inner container via an O-ring. Spiral slopes are formed at regular intervals in the circumferential direction on the end face of an opening portion of the outer container.

Abstract: A sprinkler head for scattering diluted medical fluid, such as fluid fertilizer and nutritive agents, on cultivated vegetables comprising a main body connected at one end to a sprinkler head and at another end to a faucet supplying water. The main body includes a plurality of water flowing passages, an open passage connected to a medical fluid bottle, and a mixing passage. The open passage includes a passage narrowing portion for sucking medical fluid from the medical fluid bottle by increasing water flow speed relative to the rest of the open passage. The medical fluid sucked into the open passage is stirred and diluted by water flowing down the open passage. The diluted medical fluid in the open passage then flows into the mixing passage, where it can be further diluted by water flowing down the plurality of water flowing passages. The dilution ratio of the medical fluid is controlled by individually opening and closing the plurality of water flowing passages with valves.

Abstract: A letter of a correct form is engraved in a plate member in the form of a groove having a specified depth. Either a side wall on the bottom side of the groove is arranged in the form of an inclined surface inclining towards the side facing the user at a specified angle, or both of the side walls on both a top side and the bottom side of the groove are arranged in the form of inclined surfaces inclining towards the side facing the user at a specified angle. The plate member may further have indicia indicating the correct order of writing the letter and/or the bottom surface of the groove may be provided with a resistant surface providing resistance to writing. Such arrangements enable a user to naturally and effectively master correct and beautiful letters and a correct holding angle of a writing tool.