Читать книгу Harper's Outdoor Book for Boys - Joseph H. Adams - Страница 39

The wind turbine shown in Fig. 14, on the following page, is made of two hooples about thirty inches in diameter, four cross sticks, two wire hoops, and eight V-shaped tin blades.

The cross sticks, thirty inches long, are cut and lapped at the middle and attached to the edge of each hoop with screws or nails. The wire hoops are twenty-two inches in diameter, and are fastened to the cross sticks with staples. The plan of one hoople and the cross sticks, the wire hoop and the location of the blades, is shown in Fig. 15.

The outer corners of each blade are tacked fast to both the upper and lower hoople, while the inner corners are wired fast to the stout wire hoop. The blades are made from tin or sheet iron twelve inches long and six inches wide, and, when bent in the shape of a V, the width across the open end should be four inches.

The blades are depended upon to hold the upper and lower frames in place, and when the turbine is on the top of a post with a rod running through the middle of the cross sticks, around which it revolves, the wind will keep it spinning at a high speed.

Power can be developed with this turbine, but only a very small percentage as compared with a windmill the entire surface of which is continually exposed to the breeze. In the turbine only two or three of the blades are effective at any one time.