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US 4,591,678 AGranted
High power switching apparatus
AssigneeSquare D Company
InventorSimon Yin
Life of this patent
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AssigneeSquare D Company
InventorSimon Yin
Estimating the term…
A switching apparatus for disconnecting and connecting power between a power source and a load employs a vacuum switch, a knife blade or air switch coupled electrically in series with the vacuum switch and a positive interlock mechanism. In the disconnect mode, at first the bias on a springloaded movable contact of the vacuum switch is relieved; then the vacuum lock that maintains the movable contact engaged with the fixed contact in the vacuum switch is overcome to cause complete separation of the contacts, thereby breaking the connection to the power source; and finally the knife blade is moved to open the air switch and to a position providing a visual indication that the power to the load has been interrupted. A continuous force is applied to the interlock mechanism, but the disconnect process occurs sequentially in three steps. During the connect mode, the three step process is reversed.
A high power switching apparatus comprising:
A method of disconnecting a utilization load from a high power source wherein a vacuum switch, a knife blade air switch and a positive mechanical interlock are coupled in a serial configuration between the load and the power source, the vacuum switch has a fixed contact and a spring biased movable contact in close engagement, said vacuum switch being coupled to the power source, and the air switch is coupled to the load, comprising the steps of:
Dependencies are inferred from the claim text.