Typically, a taphole is sealed by a rod held in the taphole by a hardened sealing compound. In order to be able to withdraw this type of rod, a relatively substantial force must be deployed. Conventional work tools have a powerful pneumatic striking pin for this purpose. A striking pin of this type has the disadvantage, however, that it entails considerable stresses on the material, in particular on its device for coupling with the rod which, as a result, is subjected to rapid wear and to the necessity of frequent replacement. A pneumatic striking pin has the further disadvantage of being very noisy.
The document EP-B2-0,128,432 (corresponding to commonly assigned U.S. Pat. No. 4,602,770) proposes, in order to overcome these disadvantages, the use of a powerful hydraulic jack to unlock the rod from its hardened sealing compound by retracting the mount together with the rod by sliding along the jack. However, as well as being fairly complicated, this machine does not enable the rod to be completely withdrawn, only unlocked. It is therefore the work tool which must perform the withdrawal of the rod and, consequently, deploy a relatively substantial force until the rod has been completely released from the sealing compound. The object of the present invention is to provide a method and a device which enable the above disadvantages to be avoided and the rod to be withdrawn completely using a hydraulic jack.