GB770689A - Electric spark ignition apparatus for prime movers - Google Patents

Abstract

770,689. Ignition apparatus LUCAS (INDUSTRIES), Ltd. J. Sent. 27, 1955 [Oct. 8, 1954], No. 29030/54. Class 7 (4). [Also in Group XL (a) ] In an electrical ignition apparatus having a main condenser mc, Fig. 3, to be intermittently charged from an energy source, not shown, an inductance h and a control gap cg in series with each other and the main condenser and an auxiliary condenser ac connected across the control gap and at least a part of the inductance, and a spark at a sparking plug sp being obtained by discharge of the main condenser through the control gap and inductance, and comprising the combination of a cylindrical outer metal shell a, Fig. 1, which serves as one of the main condenser plates a hollow body part c of electrical insulating material within the shell serving as the dielectric of the main condenser, a metal lining d on the part c serving as the other main condenser plate, a hollow core g, g' of insulating material in which is arranged the auxiliary condenser, the inductance wound around the core and the control gap, the electrodes p, q and r of which are carried by the core, the latter carries input and output terminals m, o respectively the output terminal being adapted for attachment to the outer end of the sparking plug central electrode. To one end of the insulator c is fixed a cap e that carries an input connection whilst the inductance h is insulated from the plate d by a nylon sleeve i; the auxiliary condenser comprises a ceramic disc j with a metallic coating deposited on its opposite faces against which latter abut contacts k, n respectively. The contact n is connected to the coaxial resilient metal terminal o whilst contact k is carried by the input terminal m in abutment with a radio interference suppressing resistance w which is joined to the connections f by a spring x and a metal strip y. The annular control gap electrodes p, q and r are arranged as two concentric annular gaps on the insulator g'; the electrode q is connected to one end of the inductance h via a metal sleeve s whilst the end of the inductance is joined to the contact n through a metal strip t. The control gap may be ventilated to atmosphere by a passage v in the cap e. In a modification, the contact n and sleeve o are separate and insulated from each, and one end of the inductor h is connected to the sleeve o by the strip t and an intermediate point of the inductance is joined to the contact n by a wire or another metal strip.