| 摘要 |
PURPOSE: An insulation cross arm for supporting transmission and distribution power lines is provided to extend service life by controlling tension change which is constricted or stretched. CONSTITUTION: A cross arm main body is installed in a horizontal direction of a telephone pole. An insulator (104) is installed on the top surface of the cross arm main body. An up-and-down rod (106) is formed in the insulator and the cross arm main body to be moved up and down. A driving roller (130) is formed on the top end of the up-and-down rod. An up-and-down part comprises the driving roller and a pressing roller. |
