Abstract: An excavator has a frame attached to its rear side for mounting of an implement. The frame includes lateral limit vertical beams which are connected by upper and lower horizontal rails. The rails are separated vertically. A slide member has guide grooves which engage the top surface of the upper rail and bottom surface of the lower rail to slidably mount the slide member on the frame. A toothed rack is attached to the underside of the upper rail and is disposed behind the front surface of the rail. A drive motor attached to the slide has a pinion meshing with the toothed rack. Actuation of the motor causes the slide member to slide on the rails.