Motor

Manawatu Times, Volume 59, Issue 181, 31 July 1934, Page 4

Motor

FINGER-TIP BRAKES An electro-magnet servo braking system that is operated by a finger-tip switch on the steering wheel, is now being introduced in England. A representative of an English motoring journal recently had a demonstration run in a 10 h.p. car fitted with the new invention. The normal brakes of the cur wore used, the electro servo being a control mechanism only. The mechanism is quite small, and takes no more current from the battery during brake applications than a headlamp bulb. The car is brought smoothly to rest by a mere touch of the finger, because it increases brake pressure as the speed decreases, so that locked wheels and skids at speed nover occur. A master control on the instrument board can be set to regulato the keenness of the braking to auy desired limit, thus the brakes can be set for powerful action when touring, and on entering tho heavy traffic of a city they can l)o eased off instantly.

The normal brake pedal is retained for use if needed; for example, if the electric Unger-operated brake is set “easy” for town use, Ilie pedal can be used to apply the last ounce in an emergency stop. Iri all ordinary circumstances, however, it is as easy to stop the car (and literally glue the wheels to the road when at rest) with a touch of the finger-tip control as it is to sound the horn. FAST AND SLOW As a traffic experiment a straight road at Castlenau, Barnes, SAV., is being divided into three carriage ways by white lines. Slow vehicles will be driven along the ways nearest the kerbs and the middle way will be for last traffic. The lines are being painted in dots and if they give traffic greater speed and safety they will be laid permanently in white road surface blocks.

Three-quarters of a mile of road is being treated in this way by tho local authority at the request of tho Minister of Transport. Several services of omnibuses and motor coaches use tho road. At intervals the new white lines arc broken by pedestrian islands. Notices requesting slow traffic to remain on the extremo left-hand side of the road have been posted in various thoroughfares in London for some time, but the constant necessity for slowmoving traffic to move into the middle of the highway has in most cases rendered the scheme request of no effect. The trial is being made in Castlenau owing to the fact that the road concerned is one of the heaviest traffic routes in the country. “As far as we know this is the first place in the country where the idea has been tried,” Mr M. Williams, assistant surveyor of Barnes, stated. ‘‘.Tho information gained may be a great help to traffic everywhere.” STEAM COOLING Market success has attended flying trials in. England of a new system of evaporative, or “steam,” cooling of liquid-cooled aero engines. Further work is .now in .hand, and promises a big advance towards the ultimate

By “ Radiator."

SHOCK ABSORBERS

elimination of water-cooling by the j newer, more efficient method. The 1 system was put through severe trials. t Climbs were made to a height of 20,- i 000 ft., where the recorded temperature J was 27 degrees below zero Centigrade. - The aeroplane was glided from 20,000 J feet to ground-level. Many level flight i trials, with the engine running at full j throttle, were made at various hieghts. j But no serious defect became apparent I in the mechanism. The evaporative , system substitutes condensers for the : large lioncy-comb radiators needed in water-cooling. Water circulates within i the cylinder jackets and through a j suitably located “header” tank be- < tween engine and condenser. Steam from the tank rises to the condenser j where, it is cooled again to the liquid i state before returning to the engine J circuit. Big advantages are claimed. Less water is needed; tho weight served j in cooling liquid for a 500-h-p. engine ; amounts to approximately 1001 b. An- : other great advantage is that holes in ] a condenser have but small effect, on engine temperature. Worry about . water temperature is eliminated, and there is greatly-reduced risk of l'rccz- . ing when the machine is not in use. Steam-cooled engines warm up much • more quickly.

Good steering ;iud riding (jualities are largely linked with the suspension system, shock absorbers being the most important item, Modern shock absorbers of the hydraulic typo need little attention beyond occasional addition to the find. A special fluid is used which is little affected in viscosity by tempura ture changes, which cause considerable change in ordinary oils, but it will often be found that a slight change in adjustment will bo beneficial for warmer weather. There are several' designs of shock absorbers on the dry friction principle, but only a couple of them are still used to any considerable extent, and that mainly on fast sports cars. These need occasional adjustment to compensate for wear of the friction discs or bands, just as in the case of brakes. Usually it is comparatively simple to dismantle them if new friction material is needed. N-o exact instructions can be given for adjusting shock absorbers, as every car requires individual attention. Generally the back is much less critical than the front, and cau be set tighter. 'A rough guide is to rock the car by jumping on the running board, when the return of the chassis should bo smooth and gradual. With a fairly fast car the settings should be such that the springs will tend to remain depressed after the load is released from them. ft: shock absorbers have been taken to pieces, they should be adjusted alter reassembly so that, a tension of IlOlbs, applied by means of u spring balance, is needed to start them moving. 1 hoy are then fitted to the car, and the final setting arrived at by test. Give the most careful attention to the front, tor many blimps which appear to como from the back springs arc really the result of faulty control of the front springs, and the front adjustment is an important item in giving good steering. 'Flic springs themselves should not be lubricated unless shock absorbers are

fitter; otherwise they will be too lively. If they are oiled it may be found necessary to tighten tho shock absorbers considerably.