Vacuum-controlled spark-timing device

Abstract

Abstract A vacuum-controlled spark-timing device for combined use with a contact breaker of a gasoline engine, said device having a rotatable plate mounted for free rotation about a camshaft in a contact breaker housing, said rotatable plate having thereon a fixed contact point and a contact breaker lever pivotably mounted on said rotatable plate, said pivotable lever having thereon a cam follower in sliding contact with the cam surface of said camshaft and a movable contact point adapted to be brought into or out of electrically conductive contact with said fixed contact point upon rotation of said camshaft, a hermetically sealed casing mounted on said contact breaker housing and having a diaphragm dividing the interior of said casing into two chambers, a connecting rod sealingly extending through said casing and having one end pivotably connected to said rotatable plate and the other end secured to said diaphragm, one of said chambers being in communication with an air inlet conduit of said engine at a point upstream of a throttle valve mounted within said conduit and the other of said chambers being in communication with said conduit downstream of said throttle valve, whereby said diaphragm is displaced in one direction by the vacuum exerted to said one chamber during normal operation of said engine to cause said connecting rod to rotate said rotatable plate in one direction for thereby advancing the ignition timing of the engine and said diaphragm is displaced in the opposite direction by the vacuum exerted to said other chamber during idling or deceleration of said engine to cause said connecting rod to rotate said rotary plate in the opposite direction for thereby retarding the ignition timing.

Inventors

• 👤 Hisaji Okamoto
• 👤 Yosiaki Takeda
• 👤 Yosio Hukuhara

Bibliographic Details