A Redesigned
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Champion Sparking Plug
A REDESIGNED Champion sparking plug for commercial vehicles has made its appearance, which, although still known as the No. 10 commercial model, embodies many improvements resulting from painstaking research and experiment by the Champion Sparking Plug Co., Ltd., 83, Pall Mall, London, S.W.1, The shape of the core, for example, has been altered to give a better distribution of temperature in the lower part, so precluding the occurrence of heavy carbon deposits while, at the same time, preventing pre-ignition. To evolve this shape a series of temperature readings was taken upon a variety of designs by means of a thermo-couple inserted in a tiny tube alongside the central electrode and cemented into place to prevent gas leakage.
Another improvement is found in the gasket upon which the core takes a bearing when the gland nut is screwed home. This copper ring is now made of TI-section in such a way that when B36 pressure is applied the local stress on the core is much less than was the case with the previous type. A third improvement of importance is found in a new cementing process for preventing leakage of gas between the central electrode and the core through which it passes.
The gland nut has been increased in length and is of larger diameter than heretofore; more important, perhaps, is the fact that it has been redesigned in conjunction with the body of the plug so as to grip the core at a higher point than formerly. In consequence, the projecting part of the core has been shortened, so making it less liable to accidental damage.