Electric overvoltage gas arrester with metallic shorting mechanism

Claim 2

In an electric overvoltage arrester of the character described, the combination with a metal housing member substantially cylindrical in shape and having a closed top end and an open bottom skirt portion, of a surge voltage gas tube having cylindrical ends of metal separated by a sealed ceramic bulbous part, said gas tube being carried by the housing in a manner whereby one metal end of the gas tube depends below the open skirt portion of the same, a coil spring located on said depending end of the gas tube, a fusible element interposed between the other end of the gas tube and the closed top of the housing member, the coil spring being effective before expansion to yieldingly maintain the other end of the gas tube in contact with the fusible element and to maintain the fusible element in contact with the closed top of the housing member, a metal ring also located on said depending end of the gas tube and being positioned between the bulbous portion and the top convolution of the coil spring, said ring being normally spaced below the skirt portion due to the thickness of the fusible element and having a diameter at least equal to the skirt portion, whereby upon melting of the fusible element by an overvoltage current the coil spring upon expansion can be effective to cause the ring to move up into contact with the skirt portion of the metal housing thereby shorting the gas tube, and whereby the coil spring will thus function as a conductive path for conducting said overvoltage current to the metal housing.

Claim 3

An electric overvoltage arrester of the character as defined by claim 1, additionally including an insulating support having an opening in its top surface adapted to threadedly receive the metal housing member, said opening having a terminal button on its botton wall, and wherein said housing member when threadedly in place in the insulating support is effective to cause the coil spring to contact the terminal button.

Claim 4

In an electric overvoltage arrester of the character descirbed, the combination with a metal housing member substantially cylindrical in shape and having a closed top end and an open bottom skirt portion, of a surge voltage gas tube having cylindrical ends of metal separated by a sealed ceramic bulbous part, said gas tube being being carried by the housing in a manner whereby one metal end of the gas tube depends below the open skirt portion of the same, a fusible element interposed between the other end of the gas tube and the closed top of the housing member, a coil spring in encircling relation and in frictional contact with the depending end of the gas tube, said coil spring being effective before expansion to yieldingly maintain the other end of the gas tube in contact with the fusible element and to also maintain the fusible element in contact with the closed top of the housing member, and said coil spring having a position on the depending end of the gas tube so that the top convolution of the coil spring is normally spaced below the skirt portion due to the thickness of the fusible element, whereby upon melting of the fusible element by an overvoltage current the coil spring upon expansion can be effecitve to move the gas tube towards the closed top end to thus cause the coil spring to have electrical conductive relation with the skirt portion of the housing thereby shorting the gas tube, and whereby the coil spring will thus function as a conductive path for conducting said overvoltage current to the metal housing.

Claim 5

In an electric overvoltage arrester of the character descirbed, the combination with a metal housing member substantially cylindrical in shape and having a closed top end and an open bottom skirt portion, of a surge voltage gas tube having cylindrical ends of metal separated by a sealed ceramic bulbous part, said gas tube being being carried by the housing in a manner whereby one metal end of the gas tube depends below the open skirt portion of the same, a fusible element interposed between the other end of the gas tube and the closed top of the housing member, a coil spring in encircling relation and in frictional contact with the depending end of the gas tube, said coil spring being effective before expansion to yieldingly maintain the other end of the gas tube in contact with the fusible element and to also maintain the fusible element in contact with the closed top of the housing member, and said coil spring having a position on the depending end of the gas tube so that the top convolution of the coil spring is normally spaced below the skirt portion due to the thickness of the fusible element, whereby upon melting of the fusible element by an overvoltage current the coil spring upon expansion can be effecitve to move the gas tube towards the closed top end to thus cause the coil spring to have electrical conductive relation with the skirt portion of the housing thereby shorting the gas tube, and whereby the coil spring will thus function as a conductive path for conducting said overvoltage current to the metal housing.

Claim 6

An arrester of the character as defined by claim 3, additionally including an insulating support having an opening in its top surface adapted to threadedly receive the metal housing member, said opening having a terminal button on its bottom wall, and wherein said housing member when threadedly in place in the insulating support is effective to cause the coil spring to contact the terminal button.

Claim 7

An overvoltage arrester as defined by claim 3, wherein the metal housing is adapted to be threaded in an opening, and wherein the coil spring has an enlarged top convolution of a diameter at least as large as the diameter of the skirt portion, said top convolution also having an inwardly bent end so as to resilently engage and have contact with the depending end of the gas tube immediately below the bulbous portion.