Switch apparatus for connection with a DC circuit
A switch apparatus usable in a DC circuit employs a rotatable shaft having conductors that are removably connected with two or more pairs of contacts that are situated on line conductors and load conductors and that are connected in parallel by the conductors on the shaft. In rotating the shaft to open the switch, one pair of the contacts is electrically disconnected prior to electrical disconnection of the other pair of contacts. Further rotation of the shaft causes the other pair of contact to eventually become disconnected. Electrical arcs thus form only at the air gaps between the other pair of contacts and the conductor. Magnetic field elements in the form of permanent magnets are situated in the vicinity of the air gaps of only the other pair of contacts and apply Lorentz forces to the arcs to extinguish them.
1. A switch apparatus that is structured to be connected with a DC circuit, the switch apparatus comprising:
a conduction element comprising a conductor portion and another conductor portion separated from one another;
a first pair of contacts, one of which being electrically connected with the conductor portion, and the other of which being electrically connected with the another conductor portion;
a second pair of contacts, one of which being electrically connected with the conductor portion, and the other of which being electrically connected with the another conductor portion;
a shaft;
an elongated first conductor apparatus mounted to the shaft and connectable at its ends with the first pair of contacts;
an elongated second conductor apparatus mounted to the shaft and connectable at its ends with the second pair of contacts;
the shaft being pivotable about a pivot axis among:
a first position wherein the ends of the first conductor apparatus are electrically connected with the first pair of contacts, and the ends of the second conductor apparatus are electrically connected with the second pair of contacts,
a second position wherein the ends of the first conductor apparatus are electrically connected with the first pair of contacts, and the ends of the second conductor apparatus are electrically disconnected from the second pair of contacts, and
a third position wherein a pair of air gaps exists between the first conductor apparatus and the first pair of contacts, and the ends of the second conductor apparatus are electrically disconnected from the second pair of contacts; and
an arc extinction apparatus comprising a pair of magnetic field elements, one magnetic field element of the pair of magnetic field elements being situated adjacent one first contact of the first pair of contacts and being structured to generate a magnetic field oriented parallel with the pivot axis, the other magnetic field element of the pair of magnetic field elements being situated adjacent the other first contact of the first pair of contacts and being structured to generate another magnetic field oriented parallel with the pivot axis, the magnetic field and the another magnetic field having their north poles pointed in the same direction.
2. The arc extinction apparatus of claim 1 wherein the pair of magnetic field elements comprise permanent magnets.
3. The arc extinction apparatus of claim 2 wherein each magnetic field element of the pair of magnetic field elements comprises a pair of permanent magnets which are situated at alternate sides of a first contact of the pair of contacts and whose north poles are pointed in the same direction.
4. The arc extinction apparatus of claim 1 wherein the pair of magnetic fields in the third position are structured to simultaneously subject at least a portion of each of a pair of electrical arcs at the air gaps to Lorentz forces in the same direction.
5. The arc extinction apparatus of claim 1 wherein in the third position:
a magnetic field of the pair of magnet fields is structured to subject at least a portion of an electrical arc at an air gap of the pair of air gaps to Lorentz forces in a first direction away from the pivot axis when DC of a first polarity is applied to the switch apparatus; and
another magnetic field of the pair of magnet fields is structured to subject at least a portion of another electrical arc at another air gap of the pair of air gaps to Lorentz forces in a second direction away from the pivot axis when DC of a second polarity is applied to the switch apparatus.
6. The arc extinction apparatus of claim 5 wherein the first direction away from the pivot axis and the second direction away from the pivot axis are generally opposite one another.
7. The arc extinction apparatus of claim 1 wherein the shaft is pivotable about the pivot axis between the first and third positions, and wherein the second position is rotationally disposed between the first and third positions.
8. The arc extinction apparatus of claim 1 wherein the first conductor apparatus and the second conductor apparatus are oriented parallel with one another.
9. The arc extinction apparatus of claim 1 wherein in the first position the first conductor apparatus and the second conductor apparatus both electrically connect together the conductor portion and the another conductor portion.