Patent ID: 7559377

Claim:
Construction apparatus employing a tool, the apparatus comprising: a mast; a rotary drive for driving the tool; a slide guided in a longitudinally displaceable manner on a front side of the mast for accommodating the tool, the slide including a lower connecting member for accommodating the rotary drive for driving the tool; two front plates pivotally mounted to the lower connecting member and extending substantially parallel to lateral sides of the mast, the two front plates each having inner and outer sides; two drive chains into which the slide is suspended, the two drive chains arranged longitudinally to the mast; two drive pinions coaxially-arranged and rotatably supported on the inner sides of the two front plates, the two drive pinions being engaged with a respective one of the two drive chains; two driving devices to drive the two drive pinions in a rotational manner for the longitudinal displacement of the slide, the two driving devices being arranged on the outer sides of the two front plates; and the rotary drive arranged on the lower connecting member between the two front plates, wherein the two drive chains and the two drive pinions are arranged in the direction of the slide in front of the front side of the mast; the two drive chains revolve around the associated drive pinion on a front side of the pinion facing away from the mast while generating equal pressing forces directed towards the front side of the mast.