For DRIVERS MECHANICS & FOREMEN.
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A PRIZE OF TEN SHILLINGS is awarded each week to the sender of the best letter which we publi6h on this page ; all others are paid for at the rate of a. penny a line, with an allowance for photographs. All notes are ,edited before beinff Published. Mention your employer's name, in confidenbe, as evidence Of good faith. Address, D. 112. and F„, "The Commercial Motor," 7-16, .Rosobery Avenue,. London, B.C. 1.
Lamps Alight—
On Saturday, the 13th July, light your lamps at 9.41 in London, 10.48 in Edinburgh, 10.6 in Newcastle, 10.2 in Liverpool, 9.53 in Birmingham, 9.51 in Bristol, and 10.45 in Dublin.
A Jig for Dismantling Springs.
fl'he sender of the following communication, has been awarded the 103, prize this week.
[1878] F.S. (Bacup) writes :—" Finding it difficult to get the road springs of a lorry, which we had bought second-hand, into good condition without dismantling them, I arranged for this to be done, and whilst the fitter's mate was dismantling the first of the set I saw that his rough-and-ready means of controlling the leaves would in all probability end in a nasty mishap. He had decided tha..t the jaws of the vice would not open sufficiently far to enable him to separate the leaves, and he had rigged -up a. rough
gantry, and I could see that the lateral support he had provided was quite inadequate. ' Stopping the job I had a jig made by the carpenter. It was quite simple, as will be gathered from the description which follows, took very little time to make, was an immediate suceess, and since then has been used in the dismantling and re-assembling of the whole of the road springs of our fleet. In fact, it so simplified a job which without it entails trouble and difficulty that any objection to doing the springs properly vanished, and I feel satisfied that we have reaped considerable benefit throughout the whole of the fleet. The drawing I enclose We have had this re-drawn, and although the apparent proportions are no quite true the dimensions are accurate.—ED.1 will readily explain the merits of the device.
"The essence of the idea was to held the leaves so that they could not fly laterally whilst being compressed or slackened out, and for this purpose a pair of double top and bottom rails were provided, whilst it was necessary to simplify the bolting and unbolting of the leaves.
"A flat board, 30ins. by 13 ins..by 1 in. formed the base' the rails, two on either side, were made of 2 in quartering. At one end a erosS member of 3 in. by 2 in. separated the rails, and at the other end a double cross member was used, the rails being halfjointed to accommodate them. A nutted bolt passed through each corner, jointing the jig together. A support piece of 2 ins. by 2 ins. was screwed to the base about 12 ins. from the -end, having the double cross member. The single cross member had a hole 'bored through it. The tools required were a small jack and its key, a saddle piece of in. iron 2 ins. wide, a box spanner. and a shifting wrench. "The jack was laid on its side in the jig, its base up to the double cross member and its upper end below the head resting on the support screwed to the base. Thus the jack centred itself between the two pairs, of rails and its head was level with the space between each pair of rails. The spring was now enter6d. between the rails, and pushed up to the end of the jig, where the single cross member was, the head of the bolt tallying with the hole bored through the cross member, through this hole being passed the box spanner, which gripped the head of the bolt.The saddle piece was, now placed in position behind the nut, and the jack screwed up to it and tightened there. It was new possible in the space left by the saddle piece to use the shifting spanner to unscrew the .,nut, the bolt being prevented from turning by the box spanner being held. The nut removed, all that had to be done was to screw hack the jack, and the spring leaves opened out without fuss or trouble.
e cleaned every leaf with emery, removing rust and scale, coated the surface with plumbago grease, and then reassembled. The jack was fully contracted and the leaves placed in position in the jig, the tommy bar of the box spanner being used through the hole in the upper cross member, so that the holes' in the leaves registered. The saddle piece was then placed in position between the head of the jack and the lowest leaf, and the jack then extended ; when the spring was fully compressed, the bolt was entered through the hole in the cross member of the jig, and then nutted up. Each spring thus lubricated was afterwards wrapped in some eases, but this .refinement was net general throughout the fleet."
A Few "Don'ts."
[18791 " T.P." (Redhill) writes :—" I recently came across an old leaflet which I have had in my tool drawer for a good number of years. It came quite fresh to me, and much of the information given therein is very useful in the workshop. I have extracted a few of the hints, and send them to you, trusting that they may be of interest to your readers.
"Don't turn a reamer backwards. Don't file against the scale of cast-iron. Don't use a, monkey wrench for a hammer. Don't try to fool your foreman, for you may get left. Don't deny spoiling a piece of work if you have done it. Don't look at the head of a chisel when you are chipping. Don't think yourself above asking questions for information. Don't screw a bolt into a newly tapped hole without oiling it. .Don't throw files one on top of another into a drawer, or on the bench. Don't make a piece of work too small and then bend the gauge to fit it. Don't work to a calliper that has been set by another man ; set it yourself. Don't cut the teeth in a gear blank unlesé you know the outside diameter is correct. Don't put a mandrel into a newly bored hole without a lubricant of some kind on it. Don't use any kind of oil but kerosene to start a loose shaft that has begun to cut. Don't try to strengthen a shaft on the lathe centres, and expect that the centres will run true afterwards. -Don't think because a piece of work has been done in one way for 20 years that it is the correct way. Don't take a difficult piece of machinery apart without having each piece marked to show where it goes back."