| 摘要 |
PURPOSE:To turn right and left a propeller connected with an engine through a universal joint and change the direction of a boat by turning a cylindrical shaft inserted in the supporting rings of a vertical frame so loosely that the shaft can rotate easily and revolving a casing through a portal frame. CONSTITUTION:If a cylindrical 3 is turned by a lever 4, a propeller 7 as well as a casing 6 in a portal frame 5 revolves right and left and the direction of a boat can be changed. |
