An irrigator comprising: a carriage that is mobile on a terrain to be irrigated, connected to a source of liquid supply, by means of a tube, having a delivery mouth that is solidly constrained to the mobile carriage, having a vertical axis, a dispensing head able to launch the liquid to a distance, borne by the mobile carriage, in fluid connection with the delivery mouth, coaxially rotatable with respect to the delivery mouth about the vertical axis, movement means, applied to the dispensing head, able to rotate the dispensing head about the rotation axis, with an alternating motion, for an outward portion in a direction and for a return portion in an opposite direction, describing a circular sector, a command system of the movement means, which commands inversion of the rotation direction of the head, comprising a feeler that is solid in rotation with the dispensing head and two end-run stops able to abuttingly receive the feeler in two distinct points of the circular trajectory described thereby, characterised in that it comprises: - an intermediate tubular support, coaxial to the axis interposed between the delivery mouth and the dispensing head, which places the mouth and the head in connection, having: - a lower portion solidly constrained to the delivery mouth and - an upper portion which supports the dispensing head, where the dispensing head is free to rotate about the axis with respect to the upper portion, - where the upper portion and the lower portion are coupled to one another, with a reciprocal rotatability, and with a liquid seal, about the axis, and - where the end-run stops are supported by the upper portion, the intermediate tubular support further comprises: - a cogged base disc provided with an enmeshing cogging, solidly constrained to the upper portion, - a base motor means, solidly constrained to the lower portion, able to move the base cogged disc in rotation, about the axis, with respect to the lower portion, so as to vary the orientation, with respect to the delivery mouth, of the end run stops of the upper portion. a carriage that is mobile on a terrain to be irrigated, connected to a source of liquid supply, by means of a tube, having a delivery mouth that is solidly constrained to the mobile carriage, having a vertical axis, a dispensing head able to launch the liquid to a distance, borne by the mobile carriage, in fluid connection with the delivery mouth, coaxially rotatable with respect to the delivery mouth about the vertical axis, movement means, applied to the dispensing head, able to rotate the dispensing head about the rotation axis, with an alternating motion, for an outward portion in a direction and for a return portion in an opposite direction, describing a circular sector, a command system of the movement means, which commands inversion of the rotation direction of the head, comprising a feeler that is solid in rotation with the dispensing head and two end-run stops able to abuttingly receive the feeler in two distinct points of the circular trajectory described thereby, characterised in that it comprises: - an intermediate tubular support, coaxial to the axis interposed between the delivery mouth and the dispensing head, which places the mouth and the head in connection, having: - a lower portion solidly constrained to the delivery mouth and - an upper portion which supports the dispensing head, where the dispensing head is free to rotate about the axis with respect to the upper portion, - where the upper portion and the lower portion are coupled to one another, with a reciprocal rotatability, and with a liquid seal, about the axis, and - where the end-run stops are supported by the upper portion, - an intermediate tubular support, coaxial to the axis interposed between the delivery mouth and the dispensing head, which places the mouth and the head in connection, having: - a lower portion solidly constrained to the delivery mouth and - an upper portion which supports the dispensing head, where the dispensing head is free to rotate about the axis with respect to the upper portion, - where the upper portion and the lower portion are coupled to one another, with a reciprocal rotatability, and with a liquid seal, about the axis, and - where the end-run stops are supported by the upper portion, the intermediate tubular support further comprises: - a cogged base disc provided with an enmeshing cogging, solidly constrained to the upper portion, - a base motor means, solidly constrained to the lower portion, able to move the base cogged disc in rotation, about the axis, with respect to the lower portion, so as to vary the orientation, with respect to the delivery mouth, of the end run stops of the upper portion. - a cogged base disc provided with an enmeshing cogging, solidly constrained to the upper portion, - a base motor means, solidly constrained to the lower portion, able to move the base cogged disc in rotation, about the axis, with respect to the lower portion, so as to vary the orientation, with respect to the delivery mouth, of the end run stops of the upper portion.