GB609549A - Improvements relating to spark ignition apparatus for internal combustion engines - Google Patents

Abstract

609,549. Timing ignition. LUCAS, Ltd., J., and SMITH, F. W. March 15, 1946, No. 8142. [Class 7 (iv)] Ignition timing adjustment is carried out by a unit comprising in combination a frame detachably connected to a housing of an interrupter and embracing a gapped portion of the housing, a non-rotatable but axially movable spindle carried by the frame, a member responsive to variations of pressure in the engine induction system and connected to one end of the spindle, a finger-piece situated at the other end of the spindle and having a screw-thread connection therewith and a spring-loaded collar slidably mounted on the spindle and connectible to an interrupter, the arrangement being such that the collar is movable relatively to the spindle under the action of the finger-piece and is movable with the spindle under the action of the member responsive to pressure variations in the engine induction system. In the Figures, an interrupter comprises an arm d, carrying a contact e, pivoted to an angularly adjustable plate h. The contact e co-operates with a fixed contact carried adjustably by the plate h. The interrupter is operated by an ignition cam c. Adjustment of the ignition timing is made by angular movement of the plate h. This movement is effected by a unit comprising a metal frame m which is detachable from a housing a of the interrupter. The frame m is detachably secured to the housing which it embraces by nuts n and a clip o. The means for adjusting the plate h is shown mainly in Fig. 3. An extension h<1> of the plate h carries a member 3 which engages a collar 2 carried by a spindle p mounted in the frame m. The spindle p is connected at one end to a collar q fixed to a diaphragm r, the diaphragm being located in a housing s, one side of which is connected to atmosphere and the other side of which is connected to the induction system of the engine through a connection t. The other end of the spindle p carries a thread v and collar z. The thread engages internal threads on a finger-piece w by which hand adjustment of the timing is carried out. Rotation of the finger-piece causes it to move axially along the spindle p and either move the collar 2 or allow it to move under the action of a spring 4. A spring x operates between the collar z and a shoulder y inside the finger-piece.