US3546538A - Spark gap - Google Patents

Description

N. CODA SPARK GAP Filed April 12, 1967 Dec. 8, 1970 mvmon 72w ATTORNEY United States Patent 3,546,538 SPARK GAP Nello Coda, Erie, Pa., assignor to Erie Technological Products, Inc, Erie, Pa., a corporation of Pennsylvania Filed Apr. 12, 1967, Ser. No. 630,349 Int. Cl. H02h 9/06 US. Cl. 317-61 3 Claims ABSTRACT OF THE DISCLOSURE A spark gap having a body of insulating material in which is molded a continuous lead wire which may be slotted intermediate the ends of the body to provide a gap which will break down whenever the voltage is excessive.

This invention is intended to provide a spark gap of simple and rugged construction for protecting electronic circuit components. In a preferred form, a continuous lead wire is molded in a cylindrical body and the lead wire is slotted at an intermediate point within the body to provide the desired spark gap. The slotting may be by punching.

In the drawing, FIG. 1 is a plan view of a spark gap as molded, FIG. 2 is an end view, FIG. 3 is a plan view of the completed spark gap, FIG. 4 is a plan view of a spark gap with a rectangular body, and FIG. 5 is an edge view of the FIG. 4 gap.

Referring first to FIG. 1 which shows the spark gap as molded, 1 indicates a generally cylindrical or pin shaped body of plastic or other moldable insulating material in which is molded a lead wire 2 which extends along the axis of the body. The lead wire may have enlargements 3 or other suitable interlocking means providing a positive anchor for the wire. Between the ends of the body is an opening or window transverse to the axis of the body and to the wire 2. The manufacture of the gap is completed by punching out a section of the wire 2 to form a spark gap 5. The length of the cut out section determines the voltage at which the gap breaks down. When a voltage surge causes breakdown of the gap, the spark is confined of the gap as a protective device are not materially or sigof the opening 4. The sheared metal ends of the lead wire between which the sparking takes place are subjected to negligible erosion by the spark so the characteristics of the gap as a protective device are not materially or significantly changed by repeated voltage surges.

The gap may be cut in a wide range of lengths so single size of molded part will accommodate a wide range of voltages. The gap is adapted to automatic assembly by the same equipment used for circuit components.

The length, breadth and thickness of the opening 4 is each greater than the corresponding dimensions of the gap 5. The electrodes of the gap are recessed inward from Patented Dec. 8, 1970 the ends of the opening 4 and are not easily damaged or distorted by rough or accidental handling.

The characteristics of the gap are determined by the opening 4 and its relation to the electrodes of the gap and not by the external shape of the body 1 or by the relation of the leads 2 to the body. In FIGS. 4 and 5,

the molded plastic body 6 is rectangular and has a U- shaped lead 7 molded into the body and projecting from one edge 8. An opening 9 transverse to the base section 10 of the lead serves the same function as the opening 4. The length of the gap 11 punched out of the section 10 after molding is determined by the desired breakdown voltage of the gap. The operating characteristics are the same as for the gap with the cylindrical body. The lead may have enlargements 12 to assist in anchoring, if desired.

What is claimed as new is:

1. An article of manufacture comprising a body of molded insulating material having a continuous lead wire with its intermediate section molded into the body and its ends extending outside the body for connection into the circuit, and a cut severing said intermediate section of wire and providing a spark gap between the severed ends of the wre which breaks down when the voltage across the gap is excessive, said body having an opening of length, breadth and thickness each greater than the corresponding dimension of the gap, said opening extending completely through the body transverse to the intermediate section of said wire with the sides and ends of the opening spaced from the spark gap formed by the cut and the severed ends of the wire being recessed inward from all sides and both ends of the opening.

2. The article of claim 1 in which the body is of generally cylindrical shape with the wire extending through and along the longitudinal axis of the body.

3. The article of claim 1 in which the body is of generally rectangular shape, the lead wire is of U shape, and the intermediate section of the lead wire which is cut to form the gap is the base section of the U.

References Cited UNITED STATES PATENTS 1,340,657 5/1920 Jacobus 313325X 1,946,695 2/1934 Ilberg 315325X 2,966,608 12/ 1960 Magnusson et al. 3 15-3 6X 3,045,143 7/1962 Shickel 3 17-6 1X 3,289,027 11/1966 Jones 3l761X 3,322,995 5/1967 Hansen et al. 31736X 3,202,873 8/1965 Feldman 315-209 JAMES D. TRAMMELL, Primary Examiner US. Cl. X.R.

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