| 摘要 |
PURPOSE:To make safe excavation work by interlocking a jack with projection and drawing action of a cylinder of an earth pressure-feed pump to expand it in an earth chamber in which the earth is stored, and maintaining a capacity in the earth chamber in a certain level. CONSTITUTION:A cylinder 18 is slid to discharge earth stored in an earth chamber 16 from a discharge-port 20a of an earth pressure-feed pump 20, the earth chamber 16 is filled with earth excavated by an excavator body to reach high pressure during the earth removing work, however, a jack 22 provided in the earth chamber 16 is interlocked with projection action of the cylinder 18 to contract it, and the capacity of the earth chamber 16 is increased to maintain earth pressure at a constant value. After that, the cylinder 18 is drawn out from the inside of the earth chamber 16 in preparation for the next stroke, and when a space for a portion thereof is made in the earth chamber 16, the jack 22 is interlocked with drawing action of the cylinder 18 and a piston 19 to expand and project it in the earth chamber 16. According to the constitution, earth pressure in the earth chamber 16 can be maintained at a certain level. |
