Electrical vacuum switch having means for generating an axial magnetic field between the contact faces

Abstract

Electrical vacuum switch having two contact members carried by contact rods for moving the contact members in and out of engagement with each other, in which each contact rod is partly surrounded by a yoke of magnetic permeable material, closely adjacent each contact member, each yoke leaving a gap between the yoke legs, so that upon moving the contact members out of engagement, the magnetic flux lines, generated in each yoke by the current through the contact rods, will traverse the arcing gap between the contact members, towards the opposing yoke, resulting in a magnetic field in the arcing gap.

I claim: 
     
       1. An electrical vacuum switch within a vacuum switch enclosure, comprising: two contact members movable in and out of engagement with one another; and   at least one magnetically permeable yoke partially surrounding each of said two contact members in a region proximate to the tangent plane of contact between said two contact members, each of said yokes including a part having a low magnetic permeability, said part having a low magnetic permeability of each of said yokes being positioned with respect to an axis through said two contact members at a location opposite to the location of said part having a low magnetic permeability of the other yoke, such that upon the passage of current through the vacuum switch each of said yokes is magnetized and the flux lines emanating from each yoke at the tangent plane of contact between the two contact members traverses substantially to the other yoke.   
     
     
       2. The vacuum switch according to claim 1, wherein each said yoke is U-shaped, and the part having a low magnetic permeability is embodied by an air gap between the legs of the yoke. 
     
     
       3. The vacuum switch according to claim 2, wherein the air gap is filled with an electrically good conducting material. 
     
     
       4. The vacuum switch according to claim 2, wherein each said yoke consists of an open ring having a rectangular cross section. 
     
     
       5. The vacuum switch according to claim 4, wherein the distance between the legs at the air gap equals the inner diameter of the ring. 
     
     
       6. The vacuum switch according to any one of claims 1, 2, 3, 4 or 5, wherein said yokes consist of iron. 
     
     
       7. The vacuum switch according to any one of claims 1, 2, 3, 4 or 5 wherein said yokes are laminated. .Iadd. 
     
     
       8.  An electrical vacuum switch, comprising: two contact members in facing relationship and supported at the free ends of aligned contact rods, at least one of the rods being axially movable with respect to the other to open and close the switch, in closed position of the switch said contact members define a contact plane therebetween and extending perpendicular to the contact rods center line, said magnetic members being positioned near said contact member at both sides of said contact plane for generating a magnetic field from the switch current, said magnetic members having a non-magnetic gap area and being rotationally displaced relative to one another such that the gap area of the one member is positioned opposite to an area of magnetic material of the other member, each magnetic member is formed by a separate ferromagnetic laminated U-shaped yoke, having a gap area with a width equal to the width of the inner diameter of the half circular portion of said yoke, said inner diameter is mainly equal to the diameter of the contact rod, each yoke being positioned around said rod adjacent the side of the associated contact member opposite to the side of said contact member facing the other contact member, such that the magnetic field generated by the switch current supports the arc extinguishing action upon opening the vacuum switch. .Iaddend. .Iadd.9. An electrical vacuum switch within a vacuum switch enclosure, comprising:   two contact members movable in and out of engagement with one another; and   at least one magnetically permeable yoke partially surrounding each of said two contact members in a region proximate to the tangent plane of contact between said two contact members, each of said yokes including a part having a low magnetic permeability, said part having a low magnetic permeability of each of said yokes being positioned with respect to an axis through said two contact members at a location opposite to the location of said part having a low magnetic permeability of the other yoke, such that upon the passage of current through the vacuum switch upon out of engagement movement of said two contact members each of said yokes is magnetized and the flux lines emanating from each yoke at the tangent plane of contact between the two contact members traverses substantially to the other yoke to enhance arc extinguishing upon opening of said   
     
     
        switch. .Iaddend. .Iadd.10.  The vacuum switch according to claim 9, wherein each said yoke is U-shaped, and the part having a low magnetic permeability is embodied by an air gap between the legs of the yoke. .Iaddend. .Iadd.11. The vacuum switch according to claim 10, wherein the air gap is filled with an electrically good conducting material. .Iaddend. .Iadd.12. The vacuum switch according to claim 10, wherein each said yoke consists of an open ring having a rectangular cross section. .Iaddend. .Iadd.13. The vacuum switch according to claim 12, wherein the distance between the legs at the air gap equals the inner diameter of the ring. .Iaddend.