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Tangyes (Limited), Birmingham
Few firms have spent so much time and money as Messrs. Tangyes in endeavouring to secure a marketable gas engine, and a walk through their museum at Cornwall Works, Soho, Birmingham, is an education in itself, for every form of engine from the Lenoir to the four cycle type, in various stages and in all sizes, trace the history of their experiments--all, however, to be discarded as so much waste effort, except the experience gained, when the Otto' patent rights expired; for Messrs. Tangyes were one of the earliest firms to take advantage of the prestige gained by the 'Otto’engine when the right to make them was no longer confined to Messrs. Crossley Brothers.
Their designs differ from Crossleys' engine in that the main cylinder and combustion chamber are made in two pieces, instead of one, whilst retaining the practice of bolting the cylinder to the main body of the engine. In the large sizes the valves are in the direct line of the explosion. In all sizes the ignition port passage is as short as possible--in fact, this has been obtained by sacrificing the appearance of the back end. However, a short ignition passage possesses many advantages, and more useful effect from the explosion can be obtained in this way than by passing round sharp corners.
Figs. 25, 26, 27, and 28 are part section and external elevation of a 3 H.P. NOM. engine. The air and gas inlet C, it will be seen, are in this size placed at the extreme end of the combustion chamber, on the centre line, whilst the exhaust valve box F is bolted to the side of the cylinder. The joint, however, in this engine would not have the same tendency to break as in some other forms, from the fact that there is no water jacket surrounding it, and the joint surfaces can be larger. The connecting rod centres are not less than three times the length of the stroke, and all engines below 16 H.P. NOM. are fitted with bent cranks. Automatic ignition is used on engines below 7 H.P. NOM., and a peculiar form of inertia governor on engines up to 10 H.P. NOM. Referring again to the sections (figs. 25, 26, and 27), it will be seen that the water jacket of the combustion chamber A is in direct communication with the jacket in the cylinder B, and all water has to pass through holes
made in the joint, as the water inlet I is in the back end and the outlet J in the main water jacket, making it somewhat
difficult to keep this joint thoroughly tight. Fig. 29 represents a 12 H.P. NOM., the design of which only differs from the 3 H.P. in that the base is made in two parts instead of one, and is fitted with a centrifugal governor, two flywheels, and arranged with a timing valve. In the larger size, however,