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).
Patent specification for improvements to electric starter systems in internal combustion engines.
| Identifier | ExFiles\Box 147\2\ scan0306 | |
| Date | 3rd March 1939 | |
| 78 H.{Arthur M. Hanbury - Head Complaints} N. LEWIS & TAYLOR CHARTERED PATENT AGENTS LEICESTER PATENT SPECIFICATION 515,731 Application Date: March 3, 1939. No. 7035/39. Complete Specification Accepted: Dec. 12, 1939. COMPLETE SPECIFICATION Improvements in or relating to Electric Starter Systems for Internal Combustion Engines I, FREDERICK LEE WITCOMB, a British Subject, of 12, Gladstone Street, Leicester, do hereby declare the nature of this invention and in what manner the same is to be performed, to be particularly described and ascertained in and by the following statement :— This invention relates to electric starter systems for internal combustion engines and has reference to such systems as are used in automobile, motor boat, aeroplane and any other classes of internal combustion engines employing battery operated means for effecting starting. It is, however, mainly the intention to apply the invention to engines employing battery coil ignition. In a battery coil ignition system the high tension output of an induction coil is commonly supplied by its secondary winding through a revolving distributor or the equivalent to each sparking plug of the engine in turn upon closure of an ignition switch as is well known to those acquainted with the art concerned. When the customary starter switch in a system of the character concerned is closed to turn the starting motor there is a momentary voltage drop across the battery and heretofore the result of this has been to cause, initially, a considerable reduction of the voltage available for starting the engine. Consequently with, for instance, a battery coil ignition system, insufficiently robust sparks are obtained at the plugs to ensure a quick start. Moreover, in starting from a cold condition an engine in which petrol is fed to the carburetter by a gravity feed or is pumped thereto by means of an electrically driven pump or the like some time usually elapses before the petrol is properly vapourised. It is found that the weak sparks initially obtained at the plugs are sometimes insufficient to ignite the incompletely vapourised petrol when starting from cold and thus it is this combination of factors which is primarily responsible for making it difficult if not impossible to achieve a quick start. The principal object of the present invention is to provide in an internal combustion engine an improved electric starting and battery coil ignition system designed to obviate the aforesaid disadvantages and to ensure a quick start upon actuation of the starter switch. As hereinbefore alluded to, however, it is to be understood that whilst the invention is mainly concerned with starter systems incorporating ignition coils it is not to be regarded as necessarily limited in this respect since it may also be adopted in cases where it is desired to compensate during starting a drop in the voltage applied to any other battery operated engine starting device or devices incorporated in the system. Broadly considered the invention consists of the provision, in an internal combustion engine starter system incorporating an ignition coil or other electrical battery operated engine starting device or devices, of an auxiliary battery which is so arranged as to be brought into circuit with the main battery for the purpose of supplementing the latter upon closure of a starter switch. In this way it is possible to prevent any initial reduction of the voltage applied to the coil or other device or devices. Thus, in its primary application to an electric starter system employing battery coil ignition the auxiliary battery is arranged to be brought into circuit upon closure of the starter switch thereby enabling—despite the initial voltage drop across the main battery—a voltage at least equivalent to the rated value of said main battery to be immediately applied to the ignition coil for starting. The improved arrangement is such, however, that immediately the engine has started and the starter switch is opened again, the auxiliary battery is cut out of circuit and the full rated voltage of the main battery is applied to the ignition coil. As will be understood, therefore, the said auxiliary battery when in circuit acts as a “booster” to boost up the main battery during starting for the purposes hereinbefore alluded to. The auxiliary battery, the voltage of [Price 1/-] | ||