Epicyclic Gearbox Refinements
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A Resume of Recently Published Patent Specifications
PATENT No. 418,587, bearing the name of Leyland Motors, Ltd„ in conjunction with S. Markland, both of Leyland, Lancs, describes a device to be used in connection with an epicyclic gearbox so as to prevent the changing of gears under load, the object being to minimize the wear on the brake bands. The drawing shows the gear control (5) worked by a vacuum cylinder (4) from a vacuum reservoir (1). A control valve (2) governs the movement of the operating piston, and is arranged to be worked by the clutch pedal (3). By this means, the suction-operated piston can operate the gearbox only when the pedal is depressed, at which time, of course, no load is being transmitted.
Progress in Trailer Design.
PATENT No. 418,222 bears a name well known in the industry, Armstrong-Saurer Commercial Vehicles, Ltd., Scotswood Works, Newcastleupon-Tyne, which, in collaboration with P. D. Ionides, Thames House, London, S.W.1, describes a means for applying power operation to trailer brake cables.
The scheme suggested is to mount an air cylinder on the rear of the tractor, Controlled by the tractor brake mechanism and acting in unison therewith. The trailer brake cable is attached to the piston of the aircylinder through a lever having a number of holes at different distances from the fulcrum. By selecting a suitable hole for the cable connection, any desired ratio of braking effort between tractor and trailer may be obtained.
Road Transport for Rail Wagons. WHILST some inventions are directed W towards the transport of road vehicles by rail, the converse is shown in patent No. 415,420, which describes a vehicle constructed to carry railway trucks on the road, and at the same time to provide tipping apparatus. The patentee is Gothaer Waggonfabrik A.G., of Gotha, Germany.
The specification states that the problem of tipping transported railway wagons is complicated by the fact that, whilst a certain minimum height is necessary for the satisfactory _discharging of the load, it may then be too high for safety and for clearing bridges. The drawing shows the sug B48 gested solution, the wagon being lifted bodily before it is tipped. Three positions are illustrated—the lowest for travelling, the second in which both axles are lifted hydraulically, and the third in which one axle is raised to a height sufficient to discharge the load.
A Novel Tipping Mechanism.
ACONSTRUCTION of tipping body, using the existing suspension linkages for its movement, is shown in patent No. 417,770 by S. J. Boys, Oxford Street Wrirks, Pleck, Walsall. This scheme is applicable to vehicles with two rear axles; the accompanying drawing illustrates clearly the manner in which the spring linkage is adapted for its additional duty. During tipping, the trailing axle moves nearer to the leading axle, with the result that the rear of the body is brought very near to the ground,. With the addition of a tailboard it would be possible to
discharge a load with the minimum of drop, whilst loads such as cable drums could be hauled up from the ground.
Compression Variation in Oil Engines.
THE compression ratio of a compression-ignition engine is usually a compromise, due consideration having to be given to the conflicting claims of fullload requirements and starting conditions. A design of engine able to
accommodate itself to both circumstances is disclosed by E. V. Jung, Villa Strand, Jonkoping, Sweden, in Patent No. 416,281.
T h e principle lies in the provision of a seconda r y compression chamber which can be isolated or added to the main chamber by means
of a hand-controlled valve. In the drawing, the main compression space (3) is shown with the secondary chamber (2) immediately above it. A screw-down valve (1) is used to segregate the upper chamber, with a resultant increase of pressure for starting and low load conditions. In this design the injection nozzle is centrally disposed in the segregating valve, which means that the air in the upper chamber does not meet any fuel until it emerges.
A Dual Hydraulic Braking System.
AN oil pump, driven by the propellershaft, and supplying pressure for braking purposes, is suggested in patent No. 417,548 by C. •A. Roeder, 1,426, Medical Arts Building, Omaha, U.S.A. With this system, however, the retarding effort is obtainable by two methods, one by application of normal hydraulic brakes, and an alternative scheme utilizing a throttling effect caused by restricting the oil-pump output.