A Silent Change Gear.—The " Mero " Device.
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Ever since the sliding type of gear was introduced by Panhard, motor engineers and users alike have cried out for something better than this primitive and unscientific means of effecting changes of the gear ratio of a motor vehicle. In spite of innumerable patents for variable, change-speed gears, epicyclio, dog-clutch, and other types, the sliding gear is still predominant and is likely to remain so for some time to come. The greatest objections to this type of gear have been the difficulty of changing from one gear ratio to another without damaging the corners of the teeth and the production of harsh and unpleasant grinding.
Is it possible that the perfect, change-speed gear has been realised at last? Mero, Limited, Of Mero Works, Sheffield, asserts that such is the case. The means whereby this company claims to have overcome all the objections to the usual sliding type of gear is shown by the line drawing which we reproduce on this page. Unfortunately this drawing does not give sufficient detail to enable its operation to be fully understood : we hope, however, in the near future to be able to reproduce sectional line drawings and photographs of the vital parts of the mechanism of the " Mero gear. This invention, we may say, has been taken up by United Motor Industries, Ltd., of Poland Street, W.
In order to introduce this gear to the .technical Press, the maker invited a limited number of representatives of that body to a luncheon at the Trocadero, on Friday last, after which the principle of the gear was explained by the inventor, Mr. Meyer. It may interest our readers to know that the name " Mero " gear is derived from the first two
letters from the name of the inventor and the first two letters from the name of the Company's engineer, Mr. F. Rothard. Briefly, the action of the gear is as follows :—When the clutch pedal is depressed, the main clutch is, of course, withdrawn and, at the same time, a positive clutch, situated at the after end of the gearbox, is also withdrawn. It will, therefore, be seen clearly that both the main shaft and the lay shaft in the gear-box are quite free and stationary. The gears may then be slid into mesh without any of the unpleasant grinding usually associated with the sliding type of gear. As the gears are not brought into mesh while one of the shafts is being driven, it foliows that there should be practically no wear on the corners of the teeth, which might be made of much smaller pitch, and this would help to secure more silent running. Referring to the illustration, it will be seen that the clutch there shown is of the double-cone type ; the main cone is, of course, the driving one, whilst the smaller, male cone on the sliding member of the clutch is nothing more or less than a clutch brake; the object of this is to bring the gear to rest when the clutch is withdrawn. The same pedal which operates the cone clutch also operates a spring-compensated combination of a free-wheel and a positive dutch. Thearrangenient of this gear, as shown in our illustration, is merely diagrammatic and is not intended to show the application of the gear to any particular make of vehicle. The inventor claims—and we see no reason to dispute this claim—that the gear may be fitted to any existing make of vehicle at a comparatively low cost.
A Straker-Squire omnibus chassis in the service of the London Road Car Company was fitted with the " Mero " combination, still retaining its old gear-box, and we understand that this vehicle, so equipped, ran over 7,000 miles in London -service and, at the end of that time, certain file marks on the gear teeth were still visible.
Motorists who are interested in improved gears will do well to look out for the " Mero " at the forthcoming Olympia exhibition; a pleasure car fitted with this gear will give demonstrations outside the hall.