A• Self-cambering Axle
Page 47
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Arrangement of the Throttle Valves.
The carburetter throttle is connected with the gas throttle in such a manner that the one closes when the other is opened, accordingly it is possible to drive exclusively on gas or petrol, or on a mixture of both. The thiottle in the body of the mixer, by which the engine is normally controlled, is interconnected with the air-regulating shutter. A special type of mixer working on the same principle has been evolved for engines running with two carburetters.
For the various connections flexible pipes are employed, and care has to be taken that the pipe running from the cleaner to the engine rises gradually from the former to the latter so that condensed vapour may run back by gravity to the cleaner. To prevent overfilling of the water• and oil compartments in the cleaner, level-control taps are provided.
The generator is started by introducing into the' fire hole (not into the ash
AN ingenious device for use on trailers, the object of which is to allow each twin-tyred wheel automatically to maintain such a position that its vertical diameter is at right angles to the road surface at the point of contact, has been evolved by the Detroit Trailer and Machine Co. It is being handled in this country by Gaston E. Marbaix, Ltd., Vincent House, Vincent Square, London, S.W.1.
The accompanying sectional drawing shows its construction, and it will be observed that, in addition to its rocking action, it permits independent rotation of the wheels against a limited frictional resistance. On the end of the axle bed is pivoted, on a horizontal axis, a hollow stub axle, free to rock through 10 degrees, the pivot axis bi
seating the line joining the two wheel centre points.
The inner wheel is mounted on a hub running on two tapered-roller bearings, arranged one on each—side of the pivot, whilst the outer runs on a pair of similar bearings on the outer end of the stub axle, which is of smaller diameter than the inner end. Thus, the wheels always remain parallel, but are free to rock, about the horizontal pivot axis, relative to the axle bed.
The inner wheel incorporates a brake drum, containing shoes mounted on the stub axle, and a second drum bolted to the outer wheel contains shoes carried on the hub of the inner wheel.
Regardless of irregularities of road surface, the slope of the camber and so forth, each pair of wheels on the trailer will always remain automatically at right angles to the road at the particular point where they make contact with it. Accordingly, both tyres of each pair of wheels will share equally the load at all times. With the usual type of rigid axle this is not the case when on a steep camber, as the two pairs of wheels on each axle must always remain parallel to each other. Obviously, the arrangement under review must afford better road holding and diminished tyre wear.
An important contributing factor in both respects is the freedom of the wheels to rotate independently. When it is realized that, in making a rightangle turn, two wheels spaced approximately 1 ft. between centres travel around arcs of circles differing by some 2 ft. in length, the value of this characteristic is at once appreciated.
The intermediate brake, that is to say, the brake incorporating the drum bolted to the outer wheel, permanently maintains a degree of friction that will allow the brake to slip just before the tyre skids on the road.