MACHINE FOR DIGGING UNDER PIPES AND CATERPILLAR TRACTION DEVICE

The present invention relates to a machine for digging under pipes, wherein said machine comprises a frame (1) having a caterpillar drive traction device (3) mounted thereon as well as left (4) and right (5) identical working organs. The working organs (4, 5) are each made in the shape of a mount (6) which is attached to the frame (1) and capable of forced rotation about the vertical axis (7). These organs also comprise a cylindrical endless-screw-type driving cutter (8) as well as a cylindrical blade (10) attached to the mount (6) coaxially behind the cutter (8). The cutter (8) is mounted at the lower end and on the side of the mount (6) so that its rotation axis is horizontal. The machine further includes a transversal stabilisation device (98) comprising two stabilisation mechanisms (99), wherein each mechanism comprises an adjustable-height support member (100) that rests on the bottom of the trench. The traction device (3) includes a frame (78) as well as a caterpillar that comprises rigid brackets (83) and flexible support members (84). The brackets (83) extend outwardly from the external surface of the caterpillar central part. The flexible support members (84) are connected to the brackets (83) so as to be incapable of linear displacement and are made short enough so as to stretch about the profile of the pipe cross-section. This invention may be used to increase the yield of machines and to dig under pipes of a larger diameter as well as in a wider variety of soils. The present invention may also be used for the automatic digging under pipes and for installing or removing the machine without assembling or disassembling its structural elements. This machine is capable of displacement along curved pipes while avoiding insurmountable obstacles and is also capable of digging under pipes having different diameters. The present invention increases the machine reliability and durability, decreases the resistance to the displacement and also simplifies the structure of the traction device. Cette invention concerne une machine permettant de creuser sous des conduites, laquelle comprend un châssis (1) sur lequel est monté un dispositif de traction et d'entraînement à chenilles (3), ainsi que des organes de travail identiques droit (4) et gauche (5). Les organes de travail (4, 5) se présentent chacun sous forme d'un montant (6) qui est fixé sur le châssis (1) de manière à pouvoir effecteur une rotation forcée autour de l'axe vertical (7). Ces organes compren