Spark plug for internal combustion engine

US5952770A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Roland Mueller · Caledon East, CA
• Richard Adamczuk · Leonberg, DE
• Werner Herden · Gerlingen, DE
• Manfred Vogel · Ditzingen, DE
• Walter Benedikt
• Andreas Niegel · Kornwestheim, DE
• Hans-Dieter Herde · Ludwigsburg, DE
• Rudolf Pollner
• Dietrich Trachte · Leonberg, DE
• Bernd Mueller · Leonberg, DE
• Dittmar Klett · Freiberg am Neckar, DE

Key dates

• Filing date: Feb 13, 1998
• Grant date: Sep 14, 1999
• Expiry date: Feb 13, 2018

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01T13/40
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

A spark plug having a tube-shaped, metal housing, an insulator which is retained by the housing, and an inner conductor arrangement embedded in the insulator, the inner conductor arrangement comprising one connection bolt, one burn-off resistor, one contact pin, and one platinum central electrode, and four ground electrodes, which are bent towards the central electrode and protrude beyond the insulator by the width of their thickness, being secured to the housing, the contact pin being coated and being shortened in its length such that the burn-off resistor is forward-positioned as far as possible towards the spark gap, and the platinum central electrode having a nail shape, whose rear part has a smaller diameter than its front part, which extends out of the insulator.