LOW VOLTAGE SURGE ARRESTER

• US 3,798,505 A
• Filed: 09/25/1972
• Issued: 03/19/1974
• Est. Priority Date: 09/25/1972
• Status: Expired due to Term

• Current Assignee: Raymond I. Morse, Ronald M. Reckard
• Original Assignee: Raymond I. Morse, Ronald M. Reckard
• Inventors: Reckard, Ronald M., Morse, Raymond I.
• Primary Examiner(s): Miller, J. D.
• Assistant Examiner(s): Fendelman, Harvey
• Application Number:
  US05/292,079
• Time in Patent Office: 540 Days
• Field of Search: 317/61,68,69 315/36 313/243,246,269,DIG.5 337/34
• US Class Current: 361/118
• CPC Class Codes: H01T 1/16 Series resistor structurally associated with spark gap

Abstract

A secondary surge voltage arrester having a high impact resistant molded housing that is provided with supporting struts for mounting a sparkgap assembly in a desired, predetermined spaced relationship with respect to the interior walls of the housing thereby to minimize the risk of flashover of the sparkgap assembly. The arrester is further characterized by incorporatng a special spring that is effective to maintain a precise sparkgap electrode spacing and at the same time to limit lateral movement of the spark-gap assembly within the housing.

Claims

1. A surge voltage arrester comprising a molded insulating housing having interior wall means defining a chamber for receivIng a sparkgap assembly, a first set of supporting struts mounted on one portion of said wall means to define a first supporting plane, a second set of supporting struts mounted on another portion of said wall means to define a second supporting plane, said first and second supporting planes being disposed in substantially parallel relationship, a sparkgap assembly mounted between said first and second planes, said sparkgap assembly comprising;

first and second spaced-apart electrodes arranged to form a sparkgap therebetween, an insulating spacer disposed between said electrodes to hold them apart, a non-linear resistance valve, one side of said valve being positioned in electrically conducting relationship with said second electrode, and a generally flat metal terminal positioned in electrically conducting relationship with a second side of said valve, thereby to form a series circuit from said terminal, through said valve, across said sparkgap to the first electrode thereof;

in combination with a compression spring mounted under compression between said first electrode and said second set of struts, said spring being effective to bias said first sparkgap electrode toward said terminal thereby to hold said first and second electrodes in spaced-apart relationship against opposite sides of said spacer, said terminal being positioned in fixed relationship with respect to said first supporting plane, said spring comprising a pair of generally flat side members positioned in a common plane, a generally flat central member positioned between said side members in another plane, and a pair of resilient connecting arms respectively joining said side members to said central member, each of said side members having a pair of integral tabs projecting out of said common plane, past a portion of said second set of struts, toward the wall means, said tabs being operable to engage predetermined areas of said second set of struts thereby to prevent the side members of said spring from being moved away from said predetermined areas.

2. An invention as defined in claim 1 wherein said connecting arms are, respectively, joined to opposite ends of said central member and to oppositely-disposed ends of said side members.

3. An invention as defined in claim 2 wherein said first and second sets of supporting struts each comprise at least a pair of spaced-apart struts, each of said struts in the portions thereof defining said supporting planes, being substantially as long as the side members of said spring.

4. An invention as defined in claim 2 wherein said spring is formed of a single piece of bronze plate stock.

5. A surge voltage arrester comprising a molded insulating housing having interior wall means defining a chamber for receiving a sparkgap assembly, a first set of supporting struts integrally molded on one portion of said wall means to define a first supporting plane, a second set of supporting struts integrally molded on another portion of said wall means to define a second supporting plane, said first and second supporting planes being disposed in substantially parallel relationship, a sparkgap assembly mounted between said first and second planes, said sparkgap assembly comprising;

a plurality of electrodes arranged to define a first and a second sparkgap, a pair of non-linear resistance valves, a pair of line terminals, a ground terminal, and a plurality of support rods, said support rods being operable to maintain the line terminals in spaced apart relationship with the ground terminal disposed therebetween and with one sparkgap and one valve positioned in series circuit relationship, respectively, between each line terminal and the ground terminal;

in combination with a compression spring mounted between one of said line terminals and one of said supporting planes thereby to force the other line terminal against the set of struts defining the other supporting plane.

6. An invention as defined in claim 5 wherein said support rods are formed of a deformable plastic resin, each of said support rods being positioned through apertures in both of the line terminals thereby to form a cage around said sparkgap electrodes and valves, said cage being effective to prevent the electrodes and valves from moving from between said line terminals and the ground terminal.

7. An invention as defined in claim 6 wherein at least one of each of said rods extends beyond one of said line terminals, on opposite sides of the set of supporting struts adjacent said terminal, thereby to form limit stops that are operable to engage the sides of said supporting struts to prevent the sparkgap assembly from being moved laterally away from said struts.

8. An invention as defined in claim 7 wherein said compression spring comprises a pair of generally flat side members positioned in a common plane, a generally flat central member positioned in another plane, and a pair of resilient connecting arms joining said side members to the central member, each of said side members having a pair of integral tabs projecting out of said common plane, past a portion of said second set of struts, toward the wall means, said tabs being operable to engage predetermined areas of said second set of struts thereby to prevent said side members from being moved away from said predetermined areas.

9. An invention as defined in claim 7 wherein each of said rods is crimped adjacent the respective ends thereof to prevent said ends from being moved through the apertures in said line terminals.

10. An invention as defined in claim 9 wherein said plurality of supporting rods comprises four substantially parallel-mounted rods arranged to define the respective corners of a square within which said sparkgap assembly is caged.

11. An invention as defined in claim 5 including;

means defining a passageway through the wall means of said housing, three insulated conductors extending into said passageway, said conductors being electrically connected, respectively, to said line terminals and the ground terminal, and a body of sealing compound positioned in said passageway around said conductors to hermetically seal said chamber.

12. An invention as defined in claim 11 wherein each of said conductors includes an insulated wire at its inner end disposed in said passageway, and wherein said body of sealing compound completely encapsulates each of said uninsulated wires thereby to prevent moisture from being drawn by capillary action along said wires past the encapsulating compound into the sparkgap-assembly-receiving chamber of said arrester.