Tracked undercarriage for operating machines

1 . A tracked undercarriage for operating machines comprising:

a main frame defining a first longitudinal direction;

a track unit mounted on each of two opposite sides of said main frame and arranged parallel to said first longitudinal direction, each track unit comprising a structure and at least one track mounted on said structure; and

a sliding frame mounted on each of said two opposite sides of said main frame,

wherein said sliding frame comprises:

a longitudinal member arranged parallel to said first longitudinal direction and interposed between said main frame and the corresponding track unit;

first constraining means, for slidingly constraining said longitudinal member to said main frame, said first constraining means being configured to enable said longitudinal member to translate with respect to said main frame in a second translation direction, orthogonal to said longitudinal direction;

second constraining means, for rotatably securing the structure of the corresponding track unit to a corresponding longitudinal member, said second constraining means being configured to enable said track unit to rotate with respect to said longitudinal member around an axis of rotation, orthogonal to said longitudinal direction;

translation means, configured to cause a sliding of said longitudinal member with respect to said main frame in said second translation direction; and

rotation means, configured to cause a rotation of said track unit with respect to said longitudinal member around said rotation axis,

wherein said first constraining means of each sliding frame comprise at least one beam placed parallel to said second translation direction and slidably housed in a guide or seat made in said main frame, and

wherein said at least one beam of the sliding frame on one side slides inside a cavity made in the at least one beam of the sliding frame of an opposite side, such that the two sliding frames mounted on said two opposite sides together make up a telescopic structure, and can slide relative to each other between a contracted position and an extended position.

2 . The tracked undercarriage according to claim 1 , wherein said first constraining means of each sliding frame comprise at least two of said beams parallel to each other.

3 . The tracked undercarriage according to claim 1 , wherein said translation means comprise at least one hydraulic cylinder acting on said sliding frame, extension or contraction of said sliding frame causing a corresponding translation of the sliding frame with respect to the main frame.

4 . The tracked undercarriage according to claim 3 , wherein said at least one beam of each opposing sliding frame comprises internal cavities communicating with each other housing said at least one hydraulic cylinder, and wherein the contraction or extension of said at least one cylinder causes a sliding of one beam with respect to another, thereby causing a reciprocal sliding of said two sliding frames.

5 . The tracked undercarriage according to claim 3 , wherein said at least one hydraulic cylinder is of a double-acting type.

6 . The tracked undercarriage according to claim 1 , wherein said second constraining means comprise at least one connecting pin between said longitudinal member and said structure of a respective track unit, and wherein said at least one connecting pin is placed orthogonally to said first longitudinal direction and enables a rotation, around said axis of rotation, of said track unit with respect to said sliding frame.

7 . The tracked undercarriage according to claim 6 , wherein the at least one connecting pin comprises two coaxial pins of said two opposing sliding frames.

8 . The tracked undercarriage according to claim 3 , wherein said rotation means comprise at least one hydraulic cylinder hinged between a fixed point integral with said longitudinal member and at least one fixed point integral with said structure of the track unit, and wherein rotation axes of hinges of said at least one hydraulic cylinder are parallel to said axis of rotation.

9 . The tracked undercarriage according to claim 3 , wherein said at least one hydraulic cylinder of each sliding frame is controlled by a hydraulic circuit which controls an operation of said at least one hydraulic cylinder selectively, independently and/or simultaneously with said hydraulic cylinder of another sliding frame of said tracked undercarriage.