Description:

This machine served to pick up and take away earth and other debris using two or more booms of different lengths, so that work could be performed simultaneously at different levels. This model has a vertical shaft around which the horizontally-mounted booms rotate; at the end of these booms are pulleys for the raising and lowering of the troughs used to transport the excavated material. The movement of the troughs is regulated by ropes which run over a central command pulley. The troughs are shaped like rectangular boxes and the bottom is divided lengthwise into two free segments held together along the central axis by metal hinges or strips of leather; they also have feet so they can be rested on the ground, which are positioned so as to be wider than the bottom segments. The outside edges of these segments are connected, by some cords going through special holes, to a hook from which the trough hangs. The cords, kept taut by the weight of the trough, ensure the two bottom parts stay together and keep their load inside. When the troughs are lowered and their feet touch the ground, the cords are no longer under tension and the weight of the material makes the two parts of the bottom open automatically, emptying out the troughs; when these are lifted again, the bottom automatically closes once more. The machine, pulled by a rope connected at a distance to a horizontal winch with a screw and a lead screw, could advance along the ground on special ‘guide rails’; that way, it did not have to be dismantled and moved as the digging proceeded.