NEW INVENTION

Rotorua Morning Post, Volume 2, Issue 272, 12 July 1932, Page 2

NEW INVENTION

SELF-ADJUSTING TAPPET BOON FOR OWNERDRIYERS. A SIMPLE DESIGN. At very rare intervals I ani invited by serious-minded inventors and the hopeful owners of rights in other people's inventions to examine, test, and report upoii different kinds of dodges and gadgets which improve the lot of the economieally-minded owner-drivar (writes John Prioleau in the London Observer). At far m'ore frequnt intervals, I am sent things, with the same object in view, which are to be frank, so much junk. The facts are that remarkably few things have heen invented which improve the perfcrmance, comfort, or life of a motor car. The designer and manufacturer can, as a rule, be expected to know more about cars than the haphazard inventor. I say haphazard advisedly, bearing in mind the struggles of so many brilliant people for so many years to produce such things as lamps which give a proper driving light without blinding other people on the road; a carhuretter that is one hundred per cent. efficient; springs or sprirvg-controllers that 'ensure comfortable travel at all times; and batteries that have a long life, weigh little, and do not require more attention than the rest of the car put together. As va rule they devote their lives to their work, and, as I have had the fortunte at least twice to report in the Observer — in the matter of lamps and carburetters — sometimes they attain the success they so well deserve. Old Troubles. I do not . know whether the inventor of the self-adjusting tappet I have recently examined comes in the haphazard class or not, but I am very sure that unless his invention hreaks down under prolonged test he will he as long remembered as any of his rivals. For many years we have been resigned to the depressing circumstance that progress in essential parts of motor design has been slow to the point of futility. Springs tyres, brakes and a host of smaller matters have only really improved noticeably within the past five years, but among those that have not improved at all during the past twenty-five years are valve-adjust-ments. Valves are, of course, made of far better material than they were. Those on my own car, for example, now in her fifth year of hard work, need grinding in and adjusting not more than onee in every 15,000 miles, and a dare say that record is heing beaten hy newer models, but I have the same long, difficult, irritating minute and exhausting finger-tip work to do to keep their clearances correct as was necessary in 1907. It is true that it is necessary far less often, but that is no excuse for the incredible slackness of designers i in incorporating in their latest productions mechanism that differs in no material respect from that used a

qu&rter of a century ago. Very few j owners to-day, to judge by the condition of the average engine, can have i the slightest idea of how very important accurate clearances are in a modern high-speed six-cylinder engine, of the loss of efficiency due to incorrect or unequal gaps, or of waste fuel. It is not only a question of smooth and quiet running — though these are nonnally signs of efficiency — but of correct ttme and therefore of better performanee, and longer life. An Interesting Invention. The Self-Adjusting Tappet (with capital letters, that is it's trade name) is one of the most interesting inventions for motor cars I have ever seen, not only because of what it does, but because its design is really simple. In plain language, it consists of a phos-phor-bronze nut, the case-hardpned steel head of which is solid. This is threaded on to a p>eg which is made to drop into the existing tappet. It is nominally free to screw itself up and down that peg within wide limits (about 25 thousandths of an inch), but its movement is checked by a light coil spring. The natural tendency of a loose nut under vibration of any degree is to unscrew itself, and the result is that this head is automatically kept in unbroken contact with the bottom of the valve stem. When the latter lengthens through heat or stortens through cold, the head follows it. As the stem lengthens the spring allows the head to screw itself down. As it shortens the unscreYung tendency naturally brings the head up. What is Claimed. I have not personal 'experience of this invention yet, but a run on a four-year-old car of a type with which' I aa very familiar left me with a deep impressidn • of its ingenuity. There is no valve-noise at all, and

moving dirt and stains from leatlrar upholstery. The lemon is ruhbed on the leather with a moderate pressure, and when the surface dries an ordinary polish cloth and a little "elbow grease" will produce a really good and lasting sheen. * * $ Plutocrat's danghter: And they have the most wonderful Romney, for which they gave £20,000. Plutocrat: "Don't you believe it, Mary. The most expensive car on the market doesn't cost a quarter o' that.