AN INGENIOUS FRICTION GEAR.
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A Résumé of Recently Published Patents.
A curious arrangement of friction gear, giving infinitely variable gear ratios, up to a certain limit, is embodied in specification No. 176,645, by H. Povey. The main object which the inventor claims to have in view is that of increasing the efficiency of the transmission, especially when in low gear. He believes he has attained his object-by/ arranging the mechanism in such a manner that the 'pressure between the various friction members is automatically increased as the lower register of gear is brought into operation.
Reference should be made to the illustration of this gear which we publish in order clearly to understand the following description. The invention is shown applied to a motorcycle engine; this, of course, is merely incidental. There are three discs—the driver, which, in the example shown, also serves as the engine flywheel, the driven, and an intermediate or idler disc. The driving and driven discs are virtually vertical; the other, which transmits the drive from driver to driven, is horizontol, or nearly so. The centre line of the drieen disc is below that of the driver, to such an extent that when the intermediate disc is in contact with the outer edge of the driven disc, it is also engaged with the innermost circle of the driver. This is the position for the lowest gear.
The intermediate disc is lowered to raise the gear, during which operation its edge approaches the outer circumference of the 'driving disc and the inner circumference of the driven disc. The drieen shaft is..so aligned, however. that the driven disc is not quite parallel to the,driver, being inclined so that its top edge is nearer. The result is that when the gears are in the "low " position the spring which holds the driven disc against the idler is compressed to a greater extent than when the higher gears are engaged.
The shaft on which the idler disc re:valves is pivoted at one end, and guided between elides at the .4-Aber, so that itmay accommodate itself to the slightly different location of the centre of the disc which is brought about as the result of the inclination of the driven disc. The
usual provision is made for disengage inent of the discs, and for movement of the intermediate disc to provide different gears.
Other Patents of Interest.
In a paper on agricultural tractors which was read before the I.A.E., during the last Commercial Motor Show, the need for making tractors adaptable for cultivation of growing crops was emphasized, and it was pointed out that, for such use to be possible, some provision for adjustment of the wheel track would be necessary. Specification No. 166,873, by G. C. Davison, deals with this aspect of tractor construction and use, and ambodies just such a provision. It is, to all intents and purposes, a three-wheeled machine, the front wheel both driving and steering. The halves of the rear axle are designed to be adjustable in their bearings in the chassis, so that the width of the track of the -rear wheels may be varied in order to suit different crops, which may be sown in rows at different distances from row to row. These portions of the rear axle are, moreover, arched so that they will straddle growing plants. The Lacre Motor Car Co., Ltd., describe, in No. 176,971., several methods of mounting the body of a tip wagon so that the minimum of effort is required to tip it. The principle underlying all the constructions embodied ie that of causing the path of tho centre of gravity of the loaded body to follow a certain line which would preferably and most commonly be one which slopes downward to the rear of the chassis. In one form, which we illustrate, the body is mounted on a couple of rollers. When the body is pushed backwards, that roller near the front of the , body mounts an inclined plane, which is attached to the chassis, while the rear roller descends a slope attached to the rear of the chassis.
One feature of specification No. 176,851
is the number of mistakes in the text. In one part a shaft is referred to as a port ; in another a shaft which projects to the rear is described as having its forward end so protruding,. The subject matter is Mr. S. S. Guy s two-engined tractor chassis, and it describes the mechanism whereby either or both of the engines may be coupled, according to requirements, to the gearbox and transmission..
No. 176,890 and No. 177,125, both by R. Venzlaff and others, of Berlin, refer to a type of motor vehicle which is specially designed to negotiate uneven ground surfaces. It is a machine, in fact, Which could compete with the Tank. Instead, however, of employing caterpillar-type tracks, the chassis is supported by means of four runners, of which two are on the ground, while the other two are not. The machine is propelled along the runners which are on the ground, the while the others are projected forward, at a speed excess of is travelling. that at Which the vehicle P. A. Poppe, in No. 176,655, reminds its that, in order to obtain maximum power from an engine, a comparatively rich mixture is required—one in which the proportion of fuel to air is consideiebly greater than that which would be needed if fuel economy wuz the chief aim. The customary adjustment of an automatic carburetter is the mean of these two extremes, special settings being usually necessary when high power or special economy is sought. He then describes a carburetter construction which provides means for instantaneous adjustment to any point between and including these two limits. The method employed is that of varying the height of fuel in the jet, which may be effected in various wars, as by raising or lowering the jet itself, adjusting the heightof the needle valve seat, or adjusting the • float mechanism.