| 摘要 |
It comprises two approximately semi-cylindrical spades (21, 22) located facing one another and secured by their upper ends to a flat iron (23) bent into a U to which the spade (21) is welded while the spade (22) is mounted so that it can pivot about a horizontal pin (24) secured to the flat iron (23); a vertical tube (25) secured to the flat iron (23) approximately at its middle, to which a flyweight (27) is slidingly mounted; an elbowed tube (29) secured to the upper edge of the spade (22) and the upper end of which is connected to that of the tube (25) through the use of two coaxial horizontal cylinders (31, 32) forming a hand grip (3) and one of which, the cylinder (32), is closed and can be entirely housed in the cylinder (31) which encloses a coil spring (33) positioned between its closed end and the end of the cylinder (32) which it pushes back, which has the effect of moving the tube (29) away from the tube (25), thus exerting a lateral pressure on the spade (22) which keeps it pressed against the spade (21) during the entire duration of their penetration into the ground. <IMAGE>
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