A New Combustion Head for Petrol Engines
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A Résumé of Patent Specifications that Have Recently Been Published
THE insistent demand for lighter and more powerful engines has led designers to consider the advisability of increasing the compression ratio to values even higher than those at present used. One of the objections to a high compression, however, is the fact that the most powerful impulse occurs when the crank angle is at its least effective value, that is, at or near top dead centre. Patent No. 4043,637, from 'Bohn Aluminum and Brass Corporation, Detroit, U.S.A., discloses a design of combustion head which, it is claimed, will. permit the use of a much higher compression than usual, without this disadvantage. •
Referring to the accompanying drawing, the combustion space is divided into two portions (1 and 3) by an intervening wall (4). Through this wall runs a passage (2), connecting the two cavities. The cross-sectional area of this passage is, it is stated, of great importance. The two cavities are, of course, separate only when the piston is at its upper limit, as the piston crown forms the lower boundary. In operation, ignition takes place in the larger chamber, but the charge in the other is stated to be delayed in firing until the piston has appreciably descended in the cylinder.
Braking and Jacking Hydraulically.
0 T H hydraulic braking and 1../ hydraulic jacking are already wellestablished methods, and in patent No. 4:38,120 is shown an ingenious scheme for utilizing the same apparatus for operating both inechaniams. The patentee is the well-known concern; S. Smith' and Stilts (Motel. Aecesseries), Ltd., Cricklewood; London, N.W.2, in collaboration with F. G. Eckford.
The brakes are worked in the conventional manner by a pedal-operated master-cylinder, which is piped to the four assemblies on the wheels. The hydraulic jacking cylinders, one at each corner, are piped to a distributing centre, and thence to a high-pressure pump. This pump is constructed on the differential-piston principle, and is worked from the oil pressure of the master cylinder.
When it is desired to jack up the vehicle, all that has to be done is to move the control valve, after which a few successive strokes of the brake pedal will lower the jack pistons and lift the vehicle.
Starting Arrangements for Oil Engines.
THERE is little doubt that the starting of an, oil engine in very cold weather is still a problem, and some proposed remedies are. suggested in patent No. 438,769 by Robert Bosch A.G., Stuttgart, Germany. The specification states that, whilst the provision of incandescent heater plugs may give
B42 some assistance, in very cold weather these are not sufficient,' and recourse may have to be made to filling the water-jacket with hot' water, or some other equally inconvenient expedient.
The suggested remedy consists of arranging for the intake pipe of the engine to be supplied with oil vapour
instead of only with air. The drawing. shows one form of the system, and in this case the intake pipe (3) has in its length a small well (4) in which is' located an electric heater element worked from the vehicle batteries. A hand fuel pump (I) is used to supply.
the well with fuel oil. • In operation, a charge of oil is • pumped into the well, and the heater switched on; this vaporizes the oil,', and when the engine is revolved the vapour is drawn into the cylinders.. The ignition of this charge takes place' in the main cylinder, whereas in the type of engine shown, combustion, during normal running originates in' the pre-combustion chamber. '
Improvements in Torque Converters.
TO eliminate fluid drag 'in hydraulic torque converters, in order to
facili tate gear‘changing, isthe object of patent .No. 438,616, which bears the ' names F. W.' anise and the •Birthing-. ham Small Arrits Co.:, Ltd., bcitli of •
Stnall Heath; Birmingham. •• :
The procedure adopted is to arrange, for the Vanes on the driving member to be slid in or out of action'as required. ' In the accompanying dm:wing, .driving vanes 5 are shown out of action, being withdrawn from the fluid circuit comprising vanes 4 and casing 3. . To initiate the drive, the collar (1) is slid to"the right, which brings vanes 5 into the space adjacent to the rotor (4). To permit this movement. while keeping the casing (3) reasonably fluidtight, a series -of saw-cuts (2) is provided; these are made a close tit on the driving vanes.'
Motor Spirit from Rubber.
THE day may come ,when fuel will have to be obtained' from vegetable sources,. and some interesting experiments in this connection are disclosed in•patent No. 438,811 by C. At Cawley arid J. C. King, both of the Fuel Research Station, Blackwall Lane, Lein..don, S.E.10.
The specification deals with the treatment of rubber by means of highpressure hydrogenation in the presence of suitable catalysts. The results are surprising, it being possible, the inventors Claim., to obtain up to 63 per cent. (by weight) of a water-white stable light spirit, suitable for use as'a motor fuel without refining. Moreover, by suitable adjustment of temperature and pressure, it has also been found possible to produce lubricating oils of varying degrees of viscosity. Those interested should obtain a copy of the specification, which gives full details of the treatment and the substances used as catalytic agents.