Patent ID: 8944519
Filing Date: 2015-02-03
Classification: E21C,Y10T

Abstract:
1. A rack and pinion arrangement for advancing a mining extraction machine provided with a travel drive having a toothed driving sprocket, in particular of a shearer loader, the rack and pinion arrangement comprising; a rack and pinion rod, the rack and pinion rod including a carrier bar, a guide bar and also a plurality of inner rack and pinion teeth, the tooth flanks of which diverge from one another, for interaction of a tooth profile of the inner rack and pinion teeth with teeth of an associated driving sprocket, towards the tooth head and which are arranged with a predefined pitch dimension relative to one another between the carrier bar and the guide bar; and a respective end tooth being arranged at both ends of the rack and pinion rod; wherein the end tooth profile of the end tooth has a change in radius of curvature, and the tooth profile of the inner rack and pinion teeth has a change in radius of curvature, and the change in radius of curvature of the end teeth is positioned lower than the change in radius of the inner rack and pinion teeth, and the end tooth head of the end teeth is positioned lower than the tooth heads of the inner rack and pinion teeth, and the end tooth in the region of the change in radius of curvature has a greater tooth width than the inner rack and pinion teeth in the region of the change in radius of curvature.