Center turn and twist mechanism of a switchgear

A method in a switchgear having a turn and twist mechanism for electrical connection and disconnection, the switchgear comprising a contact system for electrical current conduction and bus transfer switching, the contact system comprising a fixed contact assembly and a movable contact assembly, wherein the turn and twist mechanism drives the movable contact assembly for one of engagement and disengagement of one or more movable contacts with one or more corresponding fixed contacts, the method comprising:

• rotating a driving base of a driving assembly of the switchgear about a first axis in a first direction to engage the one or more movable contacts with the one or more corresponding fixed contacts, the driving assembly comprising the driving base, a floating carrier, and a driving pin arrangement, wherein the driving assembly is mechanically coupled with a cylindrical pipe of the movable contact assembly, the cylindrical pipe for turning about the first axis and twisting about a second axis, for one of engagement and disengagement of the one or more movable contacts with the one or more corresponding fixed contacts of the contact system, wherein during a first stage of rotation in the first direction, the driving base drives the floating carrier for turning the cylindrical pipe about the first axis, and during a second stage of rotation, the driving base drives the driving pin arrangement for twisting the cylindrical pipe about the second axis, wherein the floating carrier is mounted on the driving base and mechanically coupled with the rotation of the driving base such that during the first stage of rotation, the floating carrier rotates about the first axis in response to the rotation of the driving base, and in turn rotates the cylindrical pipe about the first axis, wherein the floating carrier comprises two parallel plates having circular openings for supporting the cylindrical pipe such that centers of the circular openings are positioned on the second axis, wherein the driving pin arrangement comprising three pins, wherein two pins are two parallel pins mounted on the driving base, and a third pin is attached with the cylindrical pipe, such that the third pin is mechanically coupled to movement of the two parallel pins mounted on the driving base, wherein during the second stage of rotation, the rotation of the driving base causes the two parallel pins to move the third pin for rotating the cylindrical pipe about the second axis;
• responsive to rotating the driving base in the first direction, the driving base drives the floating carrier to turn the cylindrical pipe about the first axis during the first stage of rotation to bring the movable contact assembly proximal to the fixed contact assembly, and the driving base drives the driving pin arrangement to twist the cylindrical pipe about the second axis during the second stage of rotation for engagement of the one or more movable contacts with the one or more corresponding fixed contacts;
• and
• rotating the driving base of the driving assembly of the switchgear about the first axis in a second direction to disengage the one or more movable contacts with the one or more corresponding fixed contacts,
• wherein responsive to rotating the driving base about the first axis in the second direction, the driving base drives the driving pin arrangement to twist the cylindrical pipe about the second axis, and thereafter drives the floating carrier to turn the cylindrical pipe about the first axis to move the movable contact assembly away from the fixed contact assembly.