Opinions from Others.
Page 27
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The Editor invites correspondence on all subjects connected with the use of commercial motors. Letters should be on one side of the paper only, and type.written by Preference. The right of abbreviation is reserved, and no responsibility for views expressed is accepted. In the case of experiences, names of towns or localities may be withheld.
Cast-steel Wheels for Commercial Vehicles.
The Editor, THE COMMERCIAL MOTOR.
[1216] Sir,---With wheels as at present designed, there are a considerable number of fractures of the spokes close up to the rim and there is very little resiliency; such fractures are no doubt largely due to lack of resiliency.
Years ago the makers of large cast-iron pulleys found that strength was in no way diminished but was rather Mc/ eased and much better results were obtained in running by making the arms or spokes either curved or straight tangentially from the boss to the rim. This to a very large extent overcame the trouble of cracked arms and bosses and I suggest the same method might well be applied to cast-steel wheels for commercial vehicles with beneficial results -Yours faithfully, MIDLAND USER.
A Body-builder on the Control of the Machine.
The Editor, THE COMMERCIAL MOTOR.
[1217] Sir,—In reference to your footnote to my
letter which You have published in your issue of the 5th inst., you conclude by saying " We contend that they (the dimensions) are adequate for commercial vehicle purposes." We understand that you were in favour of giving reasonable comfort to the drivers of commercial vehicles. We maintain that 9 in. is more comfortable than 5 in., even with the cushion set back, and the additional 4 in. does not mean any more expense or taking up any more room on the chassis It is necessary to be rather emphatic on this subject, since it is not unknown for the van-body builder to be blamed for cramping the dimensions of the driver's seat.
We may point out that the best position for the front of the cushion is on the vertical line drawn touching the back of the steering wheel. By so doing you will save 2 in. in length which is worth con
sideration.—Yours faithfully, H. J. BUTLER.
An Engineer on the Control of the Machine.
The Editor, THE COMMERCIAL MOTOR.
[1218] Sir,— I notice one of your correspondents criticises the dimensions you suggested recently for the arrangement of seat and steering wheel, in your article "Control of the Vehicle." Now I have considered this clearance question very carefully, and I see no reason for deviating from your original dimensions. The height and rake of the steering column, as pointed out in your article, present a very convenient position, in my opinion, for the steering hand wheel itself, and for the plane of the finger levers and quadrant. This point is most important : it is shown, as I prefer it myself, in your suggested disposition.
If, as your correspondent, Mr. Butler, suggests, the seat be carried forward 2 in. and the steering wheel raised another 4 in.. then the driver's elbows would be more likely to foul his body, whereas according to your own dimensions his arms are at a convenient resting point instead of being awkwardly placed in mid-air. I have one instance in mind of a well-known make of commercial motor where the knee clearance, with cushion uncompressed, is barely 5 in., yet I can speak from actual experience as to its giving sufficient room when one is seated. The nrst of the new Wolseley vans, if I remember rightly, shows just over 6 in. clearance.
In conclusion, I would remind Mr. Butler thet the lower periphery of the wheel is between the 'river's knees and not directly over them.
Yours faithfully, CHIEF DRAUGHTSMAN. Itsight's Wooden Tires.
The Editor, THE COMMERCIAL MOTOR.
[1219] Sir,—In August, 1911, THE COMMERCIAL MOTOR illustrated my patent wooden tires, fitted to a 6 h.p. Darracq car. This was run about 700 miles ; it was then decided to fit the wheels to a one-ton trolley. A private limited company was formed last
summer, and a 15 h.p. Panhard was bought and converted into a trolley, the tires being fitted to a pair of 40 in. wheels. It was not till the end of September that the first trial took place. After running a few hundred miles, a serious difficulty occurred, and it took some time to overcome this, but eventually it was overcome in a very satisfactory manner. The tires were hardly up to the ton weight, and were too elastic ; riding on them was very like riding on pneumatics pumped hard. So, after running a little more than 1000 miles, they were removed for careful examination. On stripping the wheels, the tires were found to be in far better condition than was expected. But, as improvements could be made, an improved set was put in hand. The making of these and experiments took up some months. There was nothing to guide me in any way whatever ; all had to be done by trial and error. The, present tires are now undergoing a series of tests, and, a-s far as they have gone, are satisfactory ; of course, some months must elapse before their durability can be ascertained, but it seems likely that, if their life is not equal to that of a solid rubber tire, it will run pretty close to it. If a block gets broken, it can be replaced quickly.
My son, who was driving for some weeks in Decem ber and January, reports that it is almost impossible for the tires to skid ; he thinks that some of the blocks would break first. I contend it is better to break a few blocks, than a passenger's head. The trolley with about a _half-ton load has been driven up to very nearly 30 miles an hour. The tires have been tried on soft ground where a solid-rubber tire would spin round without moving the car. They do not raise so much dust as rubber tires do, neither do they splash out the mud sideways ; the mud, on account of the square sides, goes out fore and aft.
It was suggested at the commencement of the trials that the bolts would break, but in running nearly 2000 miles only one bolt had been broken, and there is strong evidence to suggest that this bolt in some way had worked loose. It is possible that in very hot and dry weather some bolts may give trouble, but in the almost semi-tropical heat at the end of May none of the bolts was found to require tightening. To manufacture these tires no very expensive machinery is required, as in rubber-tire making : a circular saw, a couple of band saws, a wood planer, two drilling machines, and a light self-acting riveting machine. The stampings would be made by those firms who are specialists in that class of work. In fIct, the woo',10n tire is cheap to make.
Yours faithfully, JOHN HENRY KNIGHT.