A USEFUL MISCELLANY.
Page 69
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Interesting Contributions From Our Driver and Mechanic Readers.
A 'root for Trimming Valve Seats.
ANEW form of tool for trimming valve seats is suggested by " W.H.C.," of Tottenham, who tells us that he has found this tool make a better job of the seatings than any other kind that he has used. He also says that he has never seen it employed by anyone excepting himself.
The tool would appear to be only useful where a sufficient number of vehicles of one make has to be maintained to make it worth while having the tool Made, and it can only be used fa) such valves as those that have caps above them.
A plug is screwed to fit the ordinary cap thread, and is bored out perfectly concentric with the outer thread. Through this passes a central spindle, turned to fit the hole in the plug, and at its smaller end to fit the valve-stem hole. A cutter is attached to this spindle and a ball-thrust bearing. placed between it and the plug. The plug should have a hexagon part to permit it to be screwed down gradually to feed the cutter to its work, and a square part on the upper end of the spindle will allow a wrench to be used to rotate the, cutter. A flat cutter or a milling cutter can he used.
The particular feature of the tool appears to lie in the' very steady feeding movement which can be imparted to the cutter by the screwed plug.
A More-than-one-pull Brake.
IN describing this brake we are making a somewhat new departure, as the inventor, " A.H.," of Horwich, has applied for provisional protection for his idea, and wishes to find a firm or private investor who would develop the idea and help him to put the device on to the market. We will supply his full name and address on application.
The brake should prove particularly useful when applied to trailers, but apart from that we have heard from many experienced hauliers that a brake with which more than one pull can be taken, would be acceptable with heavy loads in hilly country.
Whether the present idea has any advantages over any brake of the kind which is already on the market we leave our readers to judge for themselves.
The brake lever spreads out in the form of a fork at its lower end. In the (*titre of this is a flanged wheel arranged for a flexible cable to coil on it, and provided with face-ratchet teeth on both sides. Through the centres of the ends of the fork passes a bolt on which the cable wheel, is free to revolve. On one side of the fork is a splined sleeve, which is anchored to the bracket at A, a similar sleeve being anchored to one member of the fork at B.
Two face ratchets are slidable on the sailed sleeves, the left one moving as the lever swings, and the other acting as a detent to prevent the cable drum from revolving backwards while the lever makes a forward movement to take,.
a second pull. The face ratchets are forced into engagement with the teeth on the cable drum by means of the bellcrank levers, which are operated by the spring plunger anti the compensating whipple-tree.
To release the brake one has only to pull the lever slightly, then press the catch,' and as the lever is pushed away the cable drum will be free to revolve on the central bolt.
A Pneumatic. Tyre Tip.
ONE of oar correspondents, " &P.," of Richmond, Yorkshire, says that he has often heard of demonstrations, etc., of the dismantling of straightsided pneumatic tyres in three minutes, but they have invariably been new tyres and wheels, whereas trouble is usually met when tyres are old and rims rusty. He often has to deal with tyres that have been on their wheels for eight or nine months, and have become very firmly attached to the rims through rust.
He tells us that he was faced with this difficulty when, single-handed, he had to remove a Dunlop tyre of 34-in. by 7-in, dimensions, which had run 15,000 miles without a puncture. He took the wheel off the vehicle, and turned it upside down on an oil drum, and although he tackled it with extra long tyre levers, he was unable to make any impression on it. He could lever the top edge of. the tyre down a little, but he could not move the lower edge, owing to baying to lever it through such a large mass of rubber. He then took the inside out of the valve, put the airpump connection on, and turned on the air very gently ; this expanded the tyre, and having no rim to obstruct it on its lower edge, forced it off. He then instantly disconnected the air pipe, and the tyre quickly deflated, having no valve inside it. He considered the precaution of removing the valve necessary to 'prevent the inner tube from ballooning when the tyre suddenly came off. After this the upper edge of the tyre came off easily.
He: further says that he has only used this method in obstinate eases, and with tyres for the slot-valve type of wheel, but he sees no reason why it should not be equally successful with tyres of the ordinary pattern, provided that care be taken in the operation. That such care is necessary is proved by the fact that several operators have been injured through tyre rims blowing off.
He points out that the walls of tyres which have adhered to their rims often get badly cut with tyre levers, so there is less risk of damage when his method
is used. He assures us that he has known this method to answer when a Lyre has had a small puncture, but, of course, it will not answer with a burst tyre.
A Useful Emergency Magneto Lamp.
IN a letter from " J.T..S.," of Petricroft, he says "a little tip not usually known is a method I once used to execute a repair to a lighting set which had failed at night. Naturally, I was inconvenienced by lack of illumination, so I tried the following experiment
which proved successful had a small six-volt inspection lamp and some flex in my kit and I hit on the idea of using the low-tension •current generated by -the magneto and wired the inspection lamp across the ignition switch while running the engine fairly fast. By this means I obtained a fairly steady light and the engine did not seem to be effected as regards running. I was thus able to see what I was about while making the necessary repairs. I do not know what the objection to this stunt is, but I did not seem to have caused any damage to the magneto armature, and for all I know, it is still running."