A switching mechanism for a dual power supply transfer switch. The switching mechanism has a switching assembly, which includes a driving plate, a driving rod, an actuator and an auxiliary mechanism. The driving plate includes an arc-shaped driving groove. The driving rod extends into the driving groove. The auxiliary mechanism includes a spring. The driving plate is able to rotate under an external force. The driving groove bypasses the driving rod when an end of the driving groove does not contact the driving rod, and the driving groove pushes the driving rod to rotate over a first angle and urges the spring to deform when the end of the driving groove contacts the driving rod. The spring recovers and drives the driving rod to rotate over a second angle after the spring having passed a dead point, thus causing the actuator turning on or off a first power supply. The switching mechanism also includes another switching assembly for switching a second power supply. A dual power supply transfer switch including the switching mechanism also is provided.

A switching mechanism for a dual power supply transfer switch. The switching mechanism has a switching assembly, which includes a driving plate, a driving rod, an actuator and an auxiliary mechanism. The driving plate includes an arc-shaped driving groove. The driving rod extends into the driving groove. The auxiliary mechanism includes a spring. The driving plate is able to rotate under an external force. The driving groove bypasses the driving rod when an end of the driving groove does not contact the driving rod, and the driving groove pushes the driving rod to rotate over a first angle and urges the spring to deform when the end of the driving groove contacts the driving rod. The spring recovers and drives the driving rod to rotate over a second angle after the spring having passed a dead point, thus causing the actuator turning on or off a first power supply. The switching mechanism also includes another switching assembly for switching a second power supply. A dual power supply transfer switch including the switching mechanism also is provided.

Some embodiments relate to an electric switching device, which comprises a switching contact, an actuation mechanism coupled to the switching contact and a motor coupled to the actuation mechanism. The actuation mechanism comprises a first spring, a first actuation plate coupled with the switching contact and a second actuation plate coupled with the motor. The actuation mechanism also comprises a first blocking element, which blocks the first actuation plate in a rotational blocking position and releases the first actuation plate in a rotational release position. The first spring is loaded by a movement of the motor. At some point in time, the second actuation plate or an actuating element connected thereto turns the first blocking element and thus releases the first actuation plate. As a consequence, the first actuation plate starts to move and finally actuates the switching contact.

The invention relates to a spring controller for high- or medium-voltage electric switchgear, the controller having a free-wheel coupling device between a crank handle or a motor and the drive shaft (1) for driving a switch contact of the switchgear and respectively providing coupling while the spring(s) (11) is/are being loaded and decoupling while the spring(s) is/are being released. The free-wheel mechanical device is incorporated in a toothed wheel (2) of the controller and includes at least one pawl (7, 70) meshing or not meshing with an inner set of teeth (4) of the toothed wheel (2).