Detachable fastening system between a male piece and a female piece, pin and female piece

A detachable fastening system between a male piece and a female piece, of the type used for the movement of earth and stones, comprising

• the female piece (1, 7) with a hollow therein, configured to house a nose of the male piece (2, 6), and with at least one through aperture (11, 11a) in a wall of the female piece,
• the male piece (2, 6) with the nose configured to be introduced in the hollow of the female piece (1, 7) and a housing (21) arranged in said nose, the entrance to said housing (21) coinciding with the at least one through aperture (11, 11a) of the female piece (1, 7) when the nose is introduced in the hollow of the female piece to define a duct through the male piece and the female piece,
• a pin (3) with a body of revolution (31) and two ends defined as a first end and a second end, the first end configured to be introduced in the duct, said pin (3) having a retaining element (35) on the body close to the second end of the pin, and
• a tensor element (4) housed in a cavity (22) arranged in an outer surface of the male piece (2, 6) and adjacent to the entrance to the housing (21) therein,
• the pin (3) has at the second end a projection (32), said projection (32) comprising an upper surface (33) and another lower surface (34), said lower surface (34) having a ramp (34a) with a certain inclination,
• adjacent to said at least one aperture (11, 11a) of the female piece (1, 7) is an exterior cavity (13) opened to an exterior of the female piece and with an inclined surface opposite that of the ramp (34a) of the projection (32) of the pin (3), and
• the ramp (34a) of the projection of the pin and the inclined surface (13a) of the cavity adjacent to the aperture (11, 11a) for introducing the pin (3) in the female piece (1, 7) interact to convert a rotational movement of the pin into a linear movement of the pin.

A structure used for the movement of earth, comprising:

• a female piece comprising:
• a hollow portion defined by walls of the female piece, the hollow portion configured to receive a nose of a male piece;
• and
• a hole through at least one of the walls of the female piece, the hole configured to receive an elongated fastening element, the hole having an axis along a length of the hole;
• the hole comprising a portion with a helical inclined surface facing an exterior of the female piece along the axis of the hole and configured to cooperate with a projection on the elongated fastening element to translate relative rotational movement of the female piece and the fastening element into relative linear movement of the female piece and the fastening element along the axis of the hole wherein the inclined surface is a one-piece integral construction with a body portion of the female piece that defines the hole;
• and wherein the inclined surface extends asymmetrically in the hole in a direction transverse to the axis of the hole.