FEED DEVICE FOR A ROCK DRILL

摘要

A feed device which is extendible by means of two cooperating feed screws and which comprises a coupling for locking the screws against rotation relative to each other or one of them relative to a girder unit. By interlocking the screws only half the feed range is available, and by locking one of them to a girder unit the full extended length can be used. One of the screws is hollow and provided with internal as well as external threads, the latter of which cooperates with a nut on a rock drill carrying slide. A hose guiding reel travels with half the speed of the rock drill and maintains a uniform tension in the hoses leading to the rock drill.