| 摘要 |
PURPOSE: An apparatus for detecting true rearward is provided to detect a true rearward when a counterweight is detachably mounted in a oil hydraulic moving crane or when an upper portion of the crane is subject to slowly rotate for operation of true rearward arrangement, so that any inconvenience resulted from several times of fine operating in a conventional art is solved and, thus, operator's convenience is improved. CONSTITUTION: An apparatus for detecting true rearward comprises a switch for selecting rearward detection(3), a warning light for indicating the selection of the rearward detection(5), a limit switch for rearward detection(4), and a relay for rearward detection(6). Under the state of turning on a swing switch(1) and a switch for selecting rearward detection(3), upper portion of a crane is slowly rotated. When the upper portion of the crane reaches to a true rearward, the limit switch for rearward detection(4) installed in an electric swivel is switched off and then the relay for rearward detection(6) is magnetized while a power source of a swing solenoid valve(2) is cut off and then rotating operation is automatically stopped.
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