RUNNING, UPKEEP AND OVERHAUL.
Page 75
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Interesting Contributions from Maintenance Engineers, Drivers and Mechanics.
• A Device for Setting Brake Shoes.
THE very useful device suggested by "D.A.," of London, N., should prove of great use when setting brake shoes by adding plates to the part where the expander cam bears, or for any kind of adjustment of shoes so that even bearing on the drum can be assured.
At present all such adjustments are, more or leas, in the nature of guesswork, as one is working in the dark. With the use of this device much of the uneven pressure of brake shoes, which is so damaging to bearings, can be avoided.
The device consists of two parts : one Is a plug of round metal—a tube is best, as it is lighter than solid material— turned to fit the bore of the wheel; into this is fixed an arm, which carries a piece which may be screwed into it and drilled and tapped to receive a setscrew.
The other part, as suggested by is a tube bored to fit the plug which goes into the bore of the wheel. We have, however, realized that the bor/lig of such a tube is a job that ..tannot be easily carried out with the outfit usually found in a garage, so we suggest using a piece of angle-iron instead, as that can be found almost anywhere. To this is fixed an arm carrying a setscrew, and having bolts with springs as shown, so that it can be easily placed on the axle arm.
In use, the plug is placed in the hub and the screw set to the bore of the drum, the angle-iron is then placed on the plug and the screw set to match up • with that on the plug member ; the angle-iron is then removed and placed on the axle sleeve, where it will act as a very efficient gauge for setting the brake shoe.
Better Means Wanted for Dealing with Valve Springs. A SUBJECT which appears to be of almost equal interest to drivers and mechanics as that of easy starting; is the difficulty of handling valve springs and cotters. As in the matter of starting, we feel sure that if designers had frequently to remove and replace the valves of their own engines we should soon have some better means for handling the springs. We so frequently receive suggestions such as a cramp. with a forked end to engage the spring while a screw presses on the top of the valve that we feel we should he tiring our readers by repeating them. Small cages or hooks which will hold the spring after it has been compressed in a vice are also so often suggested and have been illustrated on so many occasions that we need hardly repeat the suggestions. Ordinary valve lifters do not appear to be of use in all cases, because when the spring is compressed the lifter takes up all the available space around the stem, thus preventing the insertion of the holding device.
Surely drivers and mechanics should not be asked to devise and make gadgets to deal with an operation that is known to be needed at regular intervals. Could not each engine be turned out with a place in the valve chamber formed to bold some really suitable device for dealing with valve springs with ease? While designers are considering this they might also recognize that man is provided by nature with only two hands, and, bearing this in mind, could they not design tappets which could be adjusted by using two hands only?
Keeping Water Pumps in Good Condition.
WATER pumps utilized in many en gines frequently give trouble awing to leakage, states " W.E.W.," of Brentford. A cure is often effected by tightening the glands, but the tightening is often carried so far that the pump shaft is scored, after which it is impossible to prevent leakage. The packing is usually of flax or hemp, and although this is soft and pliable when first installed it becomes hard after a little service, and if tightened up 'much causes scoring.
, Metallic packing is claimed by many to be preferable, as with it scoring is not so likely to occur. The wear, when utilizing ordinary packing, may be reduced by first wrapping two folds of lead-foil around the packing. This will protect the shaft from the abrasive action, and it will last for quite a time. A shaft which has been badly scored is practically ruined, as even if fresh packing be utilized leakage will probably occur. It is sometimes possible to tin and clean up the surface, which fills up the scores, and, although this may not appear a very good method, it gives a surprising increase of life.
Wheel Pullers.
A READER, " of London, W.2, calls attention to a patent wheel puller which was described in the page of this journal which is devoted to recent patents. The device was one in which there was an appreciable amount of end play between the screw and its boss, so that when pressure had been brought to bear on the end of the axle with the screw a blow with a hammer could urge the screw forward and so help to dislodge the axle.
Our correspondent suggests a way by which the same effect can be brought about with a wheel puller of ordinary construction.
He tightens the screw against the end of the axle as much as can be done by turning the head of the screw with a spanner, then, while his mate keeps a pull on the spanner, he hits the end of the screw repeated blows with a hammer. As each blow is struck it will be found that the spanner will allow of a little more tightening of the screw, so that by the accumulated pressure of the screw and the repeated blows even the most obstinate of axles will eventually yield to this treatment.
A Strange Coincidence.
BY a strange chance we have received exactly the same suggestion from two correspondents by the same post, and both from Scotland.
" of Glasgow, and " B.S.," of Edinburgh, both suggest a way of dealing with obstinate cylinder heads when removing them.
Many cylinder heads have nothing on which one can conveniently obtain a firm hold to lift them, so uneven lifting often takes place, which often results In the breakage of a gasket.
The suggestion of both correspondents Is that old sparking plugs can have handles fitted to them so that they can be easily held. In one case a bow handle is suggested made from g-in. rod bent in the form of a ring and fitted with a nut at the bottom, whilst the other correspondent suggests screwing a 1-in. rod into the plug, then passing a piece of smaller rod through a hole drilled in it to form a handle.