# US 2017/0288376 A1 · System and method for testing breakdown voltage/dielectric strength of spark plug insulators > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0288376 A1 - Document ID: US20170288376A1 - Status: Published application - Kind: A1 - Application number: 15/625,312 - Filed: 2017-06-16 - Published: 2017-10-05 - Earliest claimed: 2014-07-30 - Assignees: Fram Group IP LLC - Applicants: Fram Group IP LLC - Inventors: Jing Zheng; Corey Eiden; Matthe B. Below - Web page: https://patentgrep.com/patent/US20170288376A1 ## CPC - H01T 13/58: Testing (testing characteristics of the spark in internal-combustion engine ignition F02P17/12) - F02P 17/00: Testing of ignition installations, e.g. in combination with adjusting (testing fuel injection apparatus F02M65/00; testing ignition installations in general F23Q23/00); Testing of ignition timing in compression-ignition engines - G01R 31/12: Testing dielectric strength or breakdown voltage {; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing (G01R31/08, G01R31/327 and G01R31/72 take precedence; measuring in plasmas G01R19/0061; measuring dielectric constants G01R27/2617; ESD, EMC or EMP testing of circuits G01R31/002)} - G01R 31/1227: {of components, parts or materials (G01R31/1209, G01R31/1218, G01R31/18 take precedence; circuits therefor G01R31/14; testing vessels of electrodes G01R31/16)} - H01T 13/60: of electrical properties - H01T: SPARK GAPS; OVERVOLTAGE ARRESTERS USING SPARK GAPS; SPARKING PLUGS; CORONA DEVICES; GENERATING IONS TO BE INTRODUCED INTO NON-ENCLOSED GASES (overvoltage protection circuits H02H) - F02P: IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES ({anti-pollution means for internal-combustion engines F02B17/00}; specially adapted for rotary-piston or oscillating-piston engines F02B53/12; {ignition of gas turbine plants F02C7/26; ignition of jet propulsion plants F02K9/95; starting of combustion engines F02N9/00}; ignition of combustion apparatus in general, glowing plugs F23Q; measuring of physical variables in general G01; controlling in general G05; data processing in general G06; electrical components in general see Section H; {ignition coils H01F38/12}; sparking plugs H01T13/00) - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract A system for testing an insulative material for a spark plug comprises a test spark plug having at least a center electrode and an insulator comprised of an insulative material surrounding at least a portion of the center electrode, wherein the insulator has an end that is closed, whereby the closed end of the insulator encloses an end of the center electrode. The system may further include a test engine that simulates engine conditions, wherein a conventional spark plug is installed in a first ignition port of the test engine and the test spark plug is installed in a second ignition portion of the test engine and a control system for controlling ignition signals to the test spark plug and the conventional spark plug. ## Claims ### Claim 1 A spark plug, comprising: a center electrode having a first end and a spaced apart second end; and an insulator formed of an insulative material surrounding at least a portion of the center electrode, wherein the insulator has an end that is closed, and whereby the closed end of the insulator encloses the second end of the center electrode. ### Claim 2 (depends on 1) The spark plug of claim 1, wherein the closed end of the insulator has a thickness of between about 0.02 inches and about 0.2 inches. ### Claim 3 (depends on 1) The spark plug of claim 1, wherein the closed end of the insulator is shaped during formation of the insulator and is pressure sealed with a resistor or contact glass prior to or after being assembled with the center electrode. ### Claim 4 (depends on 1) The spark plug of claim 1, further comprising a metal shell partially surrounding the insulator. ### Claim 5 (depends on 4) The spark plug of claim 4, wherein the insulator is pressure sealed with a resistor or contact glass prior to or after being assembled with the metal shell. ### Claim 6 (depends on 4) The spark plug of claim 4, wherein the insulator confines an electric field of the spark plug between the center electrode and the metal shell. ### Claim 7 (depends on 1) The spark plug of claim 1, wherein the second end of the center electrode comprises a tip of the center electrode. ### Claim 8 (depends on 1) The spark plug of claim 1, wherein the closed end of the insulator is made of different material than a remainder of the insulator. ### Claim 9 (depends on 1) The spark plug of claim 1, wherein the closed end of the insulator comprises glass or potting materials. ### Claim 10 (depends on 1) The spark plug of claim 1, wherein the closed end of the insulator is rounded in shape.