Advertisement for the Platomac detachable and adjustable sparking plug.
| Identifier | ExFiles\Box 33\3\ Scan209 | |
| Date | 27th April 1921 guessed | |
| The PLATOMAC Detachable and Adjustable SPARKING PLUG. (NON-CARBONISING). (Patents pending). The Platomac Non Oil-Short-Circuiting Plug is cut from steel bar by automatic machinery, the insulation is of the best steatite type. The central electrode is platinum plated by a new protected process and the electric current acting on this platinum sets up electrolytic action which splits any globule of oil between the electrode and the point, so that the Plug continues to spark satisfactorily even when submerged in oil. Special apparatus, which permits visual inspection of the Plug working under pressure, showed the Platomac to be sparking perfectly at 150-lbs. per square inch, whereas similar tests on other makes of Plugs showed that misfiring commenced at 65-lbs. per square inch, and in no other case was continuous firing observed at a pressure exceeding 105-lbs. per square inch, although numerous tests were made. The Platomac Sparking Plug has a single point only which is adjustable, as shown by the bottom illustration. The point finger has an elongated hole, which allows an adjustment of 25 thous per inch either way. We supply a spanner (the end of which is made to represent a feeler gauge) with a set of four plugs, or can be purchased retail for threepence each. The nut at the end of the electrode can be loosened to adjust or set the point, and in the event of same not being screwed tight enough, it is impossible for the nut to come off because the end of the electrode is bell mouthed or rivetted over. We recommend an adjustment of 12 to 15 thous per inch for English cars, and 15 to 17 thous per inch for American cars. [Image of a spark plug with the word 'PLATOMAC' on it] American ¾-in. Gas Thread. [Image of the bottom of a spark plug] On sale at your Garage. Price 5/- nett. Wholesale enquiries to Pickard, Dobson & Co. Ltd. PICKARD, DOBSON & CO. Ltd., Claremont Road, RUSHOLME, MANCHESTER. | ||
From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).