the fixing portion e g by means of a welded joint additionally or alternatively a press fit of the connecting portion 48 in slots on the fixing portion 47 or base plate 44 is possible the base plate 44 slides over the substrate of the floor covering to be worked e g a further floor covering 50 or a substrate 51 on its front side in the working direction 20 the base plate 44 has a bevel 45 in the vicinity of this bevel 45 or considered in the working direction shortly behind it is located the cutting point 43 for the floor covering i e the point at which the cutting means 33 cuts through the floor covering the cutting means 33 is guided in a slot and in the vicinity of the latter can project into the bevel 45 of the base plate 44 however between the substrate e g the further floor covering 50 and the lower edge of the cutting means 33 there is always a spacing x in order not to cause damage to the same firstly by means of the spacing indicator 29 the web width i e the spacing to be maintained between two cuts is set the screw of the screw clamp is loosened and the rod 31 is.