Surge protector assembly

Abstract

A surge protector assembly includes a unitary miniature surge protector having a pair of hollow electrode members extending within and sealed to a ceramic cylinder. The electrodes are provided with end walls which face one another within the cylinder to define a gap, and which are adapted to soften or melt under continuation of a predetermined arc discharge. Cylindrical contact members are slidably receivable within the electrodes and are spring-biased for urging the electrode end walls toward one another for shorting the gap, as, for example under extended breakdown conditions. The unitary surge protector and the contact members are received within a cylindrical holder having a spring means for urging the contact members toward the aforementioned end walls. The holder is threadedly received within a base member which makes electrical connection with the surge protector.

I claim: 
     
       1. A surge protector assembly comprising: a unitary surge protector including a pair of aligned conductive electrodes each comprising a hollow cylindrical member having a first closed end wall with the opposite end being open and flared to provide an annular flange, and a ceramic spacer cylinder sealed between the flanges of said electrodes for positioning said electrode end walls in facing relation internally of said cylinder forming an arc discharge gap therebetween, said spacer cylinder forming an enclosure with said electrodes,   elongated contact members within each said hollow cylindrical member and bearing on the inside of the electrode end wall in the direction of the opposite electrode, said contact members each extending outwardly past the electrode's annular flange,   a cylindrical holder within which said protector is received in substantially coaxial relation with respect to said holder, said holder being provided with a spring at one end thereof bringing pressure against one of said contact members urging the same against its corresponding electrode end wall,   and a base member receiving said holder, said base member being provided with means for matingly engaging the exterior of said holder in supporting relation, and for providing outside electrical connection for said contact members.   
     
     
       2. The assembly according to claim 1 wherein each of said contact members is substantially cylindrical and loosely slidably received within a hollow cylindrical member for longitudinal alignment of said contact members relative to said surge protector and said cylindrical holder by a said hollow cylindrical member. 
     
     
       3. The assembly according to claim 1 wherein each of said electrode end walls is centrally indented from said gap, with said contact members bearing on the opposite sides of said indentations. 
     
     
       4. The assembly according to claim 3 wherein each of said contact members is substantially cylindrical having a first diameter less than the inside diameter of said hollow cylindrical members, said contact members being loosely slidably received within said hollow cylindrical members, and at least one contact member having a length adjacent an end wall indentation which is of smaller diameter being comparable to the size of said indentation, said one contact member bearing thereagainst and forcing said end walls together under conditions of predetermined arc discharge across said gap. 
     
     
       5. The assembly according to claim 2 wherein said contact members are each provided with enlarged heads at the point where said contact members extend beyond said electrode flanges, the spacing of said heads from said flanges totaling a distance greater than the spacing of said gap. 
     
     
       6. The assembly according to claim 5 wherein said cylindrical holder is formed of insulating material having a first contact at one end for making connection with the head of one of said contact members and having a metal cap threadedly received on the other end wherein said cap includes a second contact biased by said spring against the head of the remaining contact member, said means for providing outside electrical connection including means for making connection with said cap and with said first contact as said cylindrical holder is threadedly received in said base member. 
     
     
       7. The assembly according to claim 2 further including a conductive cage longitudinally received in said holder against the pressure of said spring, said cage coaxially supporting a first of said contact members and also having spring fingers grasping the outside of said spacer cylinder received therewithin, said cylindrical holder being metal and having external threads engageable with a said base member. 
     
     
       8. The assembly according to claim 7 wherein the second of the contact members is soldered to its corresponding electrode. 
     
     
       9. A surge protector assembly comprising: a unitary surge protector including a pair of aligned conductive electrodes each comprising a hollow cylindrical member having a first closed end wall with the opposite end being open and flared outwardly to provide an annular flange, and a ceramic spacer cylinder sealed between the flanges of said electrodes for positioning the electrode end walls in facing relation interiorly of said cylinder forming an arc discharge gap therebetween, said end walls being indented from said gap, wherein said spacer cylinder forms an enclosure together with said electrodes within which a given pressure is maintained,   elongated cylindrical contact members loosely slidably received within said hollow cylindrical member for alignment longitudinally of said surge protector by said hollow cylindrical members, at least one of said contact members having a short length adjacent an end wall indentation which is of smaller diameter being comparable in size to the indentation for bearing thereagainst, each contact member extending outwardly past the electrode's annular flanges, and each contact member having an enlarged head at a distance beyond a corresponding electrode flange wherein the combined spacing of the heads from the flanges totals a distance greater than the spacing of the gap between indentations,   a cylindrical holder formed of insulating material for longitudinally receiving said surge protector and said contact members, said cylindrical holder having a first contact at one end for making connection with the head of one of said contact members and having a metal cap threadedly received on the other end of the holder wherein said cap includes a second contact spring-biased against the head of the remaining contact member,   and a base member comprising a first plate threadedly receiving said cap and making electrical contact therewith, said base member further including a second plate for making electrical connection with said first contact.   
     
     
       10. A surge protector assembly comprising: a unitary surge protector including a pair of aligned conductive electrodes each comprising a hollow cylindrical member having a first closed end wall with the opposite end being open and flared outwardly to provide an annular flange, and a ceramic spacer cylinder sealed between the flanges of said electrodes for positioning the electrode end walls in facing relation interiorly of said cylinder forming an arc discharge gap therebetween, said end walls being indented from said gap, wherein said spacer cylinder forms an enclosure together with said electrodes within which a given pressure is maintained,   first and second elongated cylindrical contact members loosely slidably received within said hollow cylindrical members and being aligned longitudinally of said surge protector by said hollow cylindrical members, at least one of said contact members having a short length adjacent an end wall indentation which is of smaller diameter being comparable in size to the indentation and bearing thereagainst, each contact member extending outwardly past the electrode's annular flanges,   a cylindrical holder formed of conductive material for longitudinally receiving said surge protector and said contact members, a conductive cage longitudinally received in said holder, said cage coaxially supporting a first of said contact members and also having spring fingers grasping the outside of said spacer cylinder received therewithin, and a spring between said cage and a first closed end of said cylindrical holder, the second end of said cylindrical holder being open,   and a base member threadedly receiving said holder and provided with electrical connecting means for making contact with the exterior of said holder, said base member also having a contact for making connection with the second contact member when said holder is threadedly engaged with said base.   
     
     
       11. A surge protector assembly comprising: a unitary surge protector including a pair of aligned conductive electrodes each comprising a hollow cylindrical member having a first closed end wall with the opposite end being open and flared to provide an annular flange, and a ceramic spacer cylinder sealed between the flanges of said electrodes for positioning said electrode end walls in facing relation internally of said cylinder forming an arc discharge .Iadd. gap .Iaddend.therebetween, said spacer cylinder forming an enclosure with said electrodes,   elongated cylindrical contact members slidably received within each said hollow cylindrical member, and bearing on the inside of the electrode end wall in the direction of the opposite electrode, said contact members each extending outwardly past the electrode's annular flange,   and a conductive cage coaxially supporting a first of said contact members at one end of said cage and said first contact member, said cage also having spring fingers receiving and grasping the outside of said spacer cylinder received therewithin, said cage extending longitudinally part way along said spacer cylinder.   
     
     
       12. The assembly according to claim 11 wherein the second contact member is soldered to its corresponding electrode. .Iadd. 13. An over voltage arrester comprising: a tubular insulating member,   a pair of electrodes mounted in a gastight manner in said tubular member and each having an electrode surface spaced apart from a corresponding electrode surface of the other electrode,   said electrodes each comprising a hollow member having a closed end wall with the opposite end being open and flared to provide a flange sealed to one end of said tubular member,   contact blocks formed of good thermal conducting material and being thermally coupled to respective ones of said electrodes conducting away heat therefrom during operation of the voltage arrester,   said electrodes facing oppositely of each other, and having their closed ends positioned inwardly from the ends of said tubular member, and   means urging the electrodes inwardly of said tubular insulating   
     
     
        member..Iaddend. .Iadd. 14.  An over voltage arrester in accordance with claim 13 wherein at least one of said contact blocks is firmly secured to a said electrode..Iaddend. .Iadd. 15. A surge protector assembly comprising: a unitary surge protector including a pair of aligned conductive electrodes each comprising a hollow member having a first closed end wall with the opposite end being open and flared to provide a flange, and a ceramic spacer cylinder sealed between the flanges of said electrodes for positioning said electrode end walls in facing relation internally of said cylinder forming an arc discharge gap therebetween, said spacer cylinder forming an enclosure with said electrodes,   contact means for each said hollow member and bearing thereon in the direction of the opposite electrode, said contact means each extending outwardly past the electrode's annular flange, and at least one of said contact means extending inside the electrode,   a holder within which said protector is received in substantially coaxial relation with respect to said holder, said holder being provided with a spring at one end thereof bringing pressure against one of said contact means urging the same toward the other, and means for engaging the other of said contact means and providing for outside electrical connection for said contact means..Iaddend.