Progress in
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RESEARCH and TECHN IQUES TYRE wear has been studied m the United States, and it has been proved that, even with full attention to tyre maintenance, the life expectancy of rubber tyres is reduced from 56,000 miles at 35 m.p.h. to 18,700 miles at 65 m.p.h, on concrete or bituminous surfaces. The average life on concrete roadways is 36.650 miles and on gravel 23,160. Driving speeds, roadway surfaces, and maintenance most directly influence the life of tyres, Speeding tyres on curves until they scream increases wear ten times, and town driving is three times as injurious to pneumatic tyres as is country driving, it is stated.
Crash-resistant
Made of synthetic rubber, plastic and nylon in combination, a new crashresistant petrol tank is said to be much lighter and twice as strong as standard tanks. It will withstand a wide range of temperatures from below freezing point to 90 degrees C.
One automobile concern in America is making parts directly horn the steel chips produced when torque-tube bushing operations on 'automatic screw machines are carried out, The chips are carefully segregated.front other turnings to .prevent contamination. They are then placed in a perforated basket in a centrifugal chip wringer, and rotated for 45 minutes to eliminate oil from their surfaces. The dry chips then pass to a shredding machine, where their size is reduced. Aftethe shredding operation, they are screened, and those that pass through the screen are employed as a basis for forming the briquettes.
A new method of cutting metals by a combination of electrical and mechanical action has been developed in the U.S.S.R. It replaces machine-saw work and is specially suitable for heat-treated steels, hard alloys and thin tubes, but is also applicable to normal sections. A revolving disc is pressed against the work, and the electric current passes from the work through an electrolyte to the disc, quickly removing the metal by electro-dynamic and electro-chemical action.
New Painting Process
Electrostatic painting is a new process which is claimed to minimize overspray waste and blisters in finishing. The particles of paint leaving the spray gun are drawn to the surface to be coated by an electro-staiic field. Similar devices, operating in reverse, remove excess paint and prevent unsightly tears.
A new method of surface treatment of mild steels and steels with low alloy content induces the passivity of such surfaces and thus increases.their corrosion resistance, It comprises a preliminary immersion in nitric acid, followed by dichromate treatment for 10 to 15 minutes at 100 degrees C. Passivity dis
appears when the surface is heated above 60 degrees C.
A new metallizing technique '' homogenizes" alloy coatings to eliminate porosity. The area to be coated is machined to the desired depth, as in conventional practice, but is left as smooth as possible rather than threaded or knurled. Next, the surface is pitted by means of multiple electric arcs until the area contains thousands of tiny depressions. After this preparation, metal spraying must or carried out immedi ately. Heating the ccating until all porosity is eliminated closely follows spraying.
An investigation has shown that zinc alloys containing aluminium up to 0.7 per cent. may be successfully soldered either by -pecial soft cadmiumcontaining solder using an active zincammonium chloride flux, or by common soft tin-lead sohier, using a nominal flux after the alloy has been coated with zinc. Zinc alloys containing up to 4 per cent, aluminium may be soldered with any soft solder, usieg a common flux, hut only aftei the alloy has been coated with a galvanic zinc layer.
Oxygen Arc-cutting Oxygen arc-cutting is a new development. A stream of oxygen is combined with the arc by means of a tubular electrode, and a cutting temperature is obtained that is 3,000 degrees F. hotter than that usually realized with common cutting methods. The process has been employed in the cutting of a wide range of metals occurring in the form of sheets, plates, and castings, as well us to cut metals in any shape and under various conditions.
A new welding technique employs special electrodes, in which more than 50 per cent, of the weld metal is contained in the coating. The process may be employed by unskilled operators, because the end of the electrode is held in contact with the work at all times, and merely drawn along the surface.
Valves are being given a hard face by means of an alloy containing 40 per cent. nickel, 32.5 per cent. chromium, 15 per cent. tungsten. 10 per cent. cobalt, and 2.5 per cent. carbon. This alloy has a Rockwell C hardness of 43 to 45, is specially resistant to the attack of lead oxides, anu is therefore highly suitable for the purpose in question.
A silver-plated spring and patent core unit fitted into the top of the hose connection or in the top of the radiator is removing old scale from the cooling system and preventing further formation of scale by the electrolytic action of a galvanic cell and the mineral content of the water.
Coil Springs for "heavies"
Nickel-chromium-molybdenum steel containing abo it 0.5 to 0.6 per cent. carbon is being used for coil springs in heavy vehicles. The alloy steel concerned is said to replace silico-manganese steel, and hardens fully in the section in which it is supplied. The springs are quenched in oil from 840 degrees C. and tempered for one hour after equalization at 480 degrees C. This treatment develops the following properties: Brinell hardness. 375 to 430; ultimate tensile strength 80 to 90 tons per sq. in ; yield point 70 to 80 tons per sq. in.
A new method of casting metal has been devised. This is the frosting or crystallization process, Li which the inside walls of the mould are cooled with circulating water. the mould itself being immersed in molten metal and left until the outside walls are covered or frosted with an even layer of the requisite thickness. The method has been successfully tried out in the manufacture of bronze bushes, and experiments are being made with other metals. Articles cast in this manner are said to be of high quality and to have a smootn surface.
Stainless and Non-chip
A stainless clad steel that will not chip, flake or peel, and that keeps a permanently rust-free surface is being applied to vehicle bumpers and other accessories. The stainless covering is applied to low-carbon steel sheets and plates in regulated thicknesses ranging from 5 to 50 per cent., and is united inseparably during the , hot rolling process. It can be polished to a high finish, which will be retained indefinitely.
The sheets withstand severe bending operations without separation of the surface covering. If deep gouging should penetrate to the low-carbon steel backing. the stainless surface can be built op again by welding and polished.
BEFORE I retired I was an outlaw At one time the police of three counties were on the look-out for me. After I had been caught, magistrates' clerks grew breathless reading out the list of previous offences.
When in reminiscent mood I take down the family album, wherein lies the key to my lawless past. On the front pages are faded daguerreotypes of my paternal grandparents. They are seated in the middle of what the modern child might mistake for a Sunday school picnic, but is really their family of 19 All these early pages I skim over quickly At the back, however, and decently separated from "the family" are seven or eight alfresco studies of a more dubious character.
There it is in all its glory—that capricious dragon of the roads, the steam-wagon of 40 years ago. There it is in the most unnatural postures— reclining on its side, standing on its nose, lying on its back, even wallowing in the middle of a pond.
All the defiant lawlessness of those pioneer days floods back into one gigantic pattern in my mind, and in the middle of it all shines the memory of a journey to Burnley on an August day in 1908.
The Sentimentalist We were on the road at about five in the morning and after taking on our 18 tons of grain at a dockside warehouse we made a detour up the Oldham Road to call at my mate's house George Strongitharna, a Yorkshireman and aptly named, was possessed of 'a head like a sieve and had forgotten his dinner basket again I cursed him for it, but I had not the heart to make him go all day without a bite. His mother's delight when she saw us put me in a happier
mood .
As we climbed slowly up the Oldham Road life seemed very good. It was a lovely morning and there was a pleasant warmth from the firebox My head fell forward on my chest. George let me sleep, obligingly putting us on the right track every time the front wheel strayed A loud clank from the back of the lorry woke me suddenly. We were running backwards! Wide awake now, I could feel the hair at the back of my neck prickling with terror. We had no brakes! In the safe seclusion of his drawing office the designer of our steam wagon had decided that wheel brakes were an unnecessary luxury The engine could serve excellently as a brake, unless, of course, the chain broke.
The chain had broken, however, A28