CARE ON CORNERS.

New Zealand Herald, Volume LXVII, Issue 20496, 22 February 1930, Page 14 (Supplement)

CARE ON CORNERS.

♦JUDGMENT IN STOPPING.

'(Probably tho worst type of motor accident which can happen on tho road is a ■head-on collision between vehicles going in opposito directions, when the striking force is tho sum of the speeds of tho two 1 llius, if two vehicles, each travelling at 30 miles an hour, meet in fi, head-on collision, tlio impact speed is 60 miles aq hour. Elementary as this fact may seem, it does not appear to be realised by many people. Tlio first lesson jto bo derived from, it is the extreme idanger of swinging out to the wrong side the road, unless it is absolutely clear Jhat no are approaching. Every ; (driver should stick to the sound old rule fiof keeping well to his left side of tho jfroad in any doubtful situation, and this fieally means slowing down. But to swing ftoufj wide from behind another vehicle, [W thus get into the lino of oncoming [(traffic, is a particularly dangerous practice, [.growing more common every day, for keeps on increasing.

i„ Somo drivers, too, havo littlo idea in J Judging stopping distances at various (speeds. Let Euch a one select a little•tised stretch of road, and mark a point Ut which the car is to bo stopped. Then fhe should approach this point at various Speeds and endeavour to gauge tlio mini- : snum distanco he requires to bring the [car safely to rest. It will be a surprise to ; ( this class of driver to find that ho does •not bring off that smooth deceleration, •'fend precise stopping at a given point, the skilled driver carries out so fjieatjyil Every day ono hcars_ screeching brakes which tell of frantic braking Efforts; and in nearly every accident much 5s due to ill-judged or unsuccessful braking efforts. The changes in stopping dis,'itances brought about by various speeds various types of road surface are also 'most useful studies which are too often

SHOOK ABSORBERS.

Now that the use of some form of shock ■fcbsorber is common practice on private ""cars, motor coaches and even goods Vehicles, it is interesting to review the Calient features of a type which is now • yery popular, the hydraulic shock absorber. Hydraulic shock absorbers have many advantages over those of the friction •jl.ype", the most important being that they hct progressively, owing to tho flow of oil following tho hydraulic law and giving little damping effect for small bumps and -Creator damping for _ large bumps. {Further,' their efficiency is constant und therefore' -frequent adjustment is unnecessary. . When travelling slowly the >Wd springs requiro very little control land, if heavily checked, will cause harshness jand. discomfort. In this condition ithe ifrictioual element of a friction type 'shock absorber is checking at its maximum, efficiency, thereby imparting to the springs «l. checking which is not requuec {As the speed of tho ear increases, the impact load on the absorber becomes /greater anil; tho efficiency of the fnctional ''tlenient becomes less, which is exactly (opposite to' what is requireu. as it means that at the higher speeds this type of absorber has very littlo control over the springs. Oil the other hand, in ft h}jVlraulic shock absorber these conditions fare reversed, as at slow, speeds the resistance is very small, but as the speed land load increase, so tho resistance of the absorber becomes greater, giving smooth riding under all conditions and efficient jcontrol of tlio road springs at high speeds. A new English shock absorber consists jbf a single vane rotor working in a pressure chamber, this chamber being' idivided by tho reacting block in which is incorporated the regulation and control tof tho oil flow. The working chamber is filled with a special oil. the viscosity of (which is very little affected by changes of atmospheric temperature, and the reacting block is provided with a non-re-turn valve, permitting the oil displaced jby the vane,, which oscillates within the "(chamber with each movement of the spring, to pass through it to the other 'sido on tho upward deflection of the 'spring, but preventing its return on recoil. jThis valve being shut, an additional orifice is provided to enable tho oil displaced to return through the reacting block, and a tapered screw regulating the size of this (orifice /is fitted so that adequate control jpyer the recoil checking action is provided.

TWO-SEATER CABS. !A fleet of two-seater taxi-cabs of untosual design will appear in London shortly. Invented by William Gowan, of Capetown, the cabs, which liavo passed all tests, will havo two curved sliding panels forming tho fi'ont of the .passenger compartment instead of doors. These operated by tho driver without leaving his seat or by the passengers. There is accommodation for two when the movable arm is raised. Heavy luggage can be taken on the front platform. The inventor eays the absence of door 3 will prevent accidents, while - the body is less costly .and weighs 2501b5. less than tho usual ton and a-half cab.

, TRADE ITEMS. It is announced in America that in future all Graham-Paige cars will be equipped with non-shattering plate glass in windows, doors and windscreens. It is stated that the Ballot, the Mathis ft.id the Ilispano-Suiza companies have amalgamated in order to compete with [American invasion of the French market. r At a recent New York show, one of the tnost striking exhibits was a sixteen-cyl-Snder Cadillac, which in nearly evqry derail was a radical departure from the previous practice of the General Motors Corporation.