An electromagnetic switch has a shaft and a movable contact member slidably supported by the shaft. The shaft is moved with a plunger when an electromagnet is formed of an electromagnetic coil receiving an electric current and attracts the plunger. The movable contact member is moved with the plunger...http://www.google.fr/patents/US7569787?utm_source=gb-gplus-shareBrevet US7569787 - Electromagnetic switch of starter
