摘要 |
The present invention relates to a quick coupler for coupling a tool like for example a scoop, shell grab or demolition tongs to a tool guide such as an excavator arm or the like, comprising a coupling receptacle for receiving a first locking part and a locking receptacle for receiving a second locking part, wherein to the coupling receptacle a securing element is associated for catching and/or securing the first locking part in the coupling receptacle, and to the locking receptacle a locking element is associated for locking the second locking part in the locking receptacle, wherein said locking element and said securing element are actuable via a common pressure circuit having an unlocking pressure port and a locking pressure port selectively connectable with a pressure source or a return line via a valve means. According to the invention, the additional securing element is actuable by a double-acting, reversible actuator and is movable both into an opening and a closing position by means of applying pressure medium from the common pressure circuit, wherein various pressure chambers of the actuator are pressurizable via a valve arrangement in dependency of a pressure level at the unlocking and/or locking pressure port of the common pressure circuit. |