A practical treatise on coach-building historical and descriptive

by James W. Burgess

When the tire has got sufficiently cold it is riveted to the felloe by countersunk rivets, one on each side of the felloe joints.

The strength or weakness of wheels plays an important part in the durability of the vehicle, for in whatever manner the various forces are mechanically met they at last concentrate themselves on the wheel; it is highly necessary, therefore, that great pains should be taken in constructing them. The stock is not necessarily the foundation on which to build a wheel, and, further, there are many objections to its being so constituted. In the first place, when its centre is all scooped out for the reception of the axle-box, and its sides are mortised out to receive the ends of the spokes, it is nothing but a mere shell. Every mortise hole is more or less a receptacle for water, which the best workmanship cannot wholly exclude; and as one part of the stock is always more porous than another, that is the part that will soonest absorb wet and begin to decay. If, therefore, the stock could be dispensed with greater durability would be insured.

Fig. 16. Fig. 17.

A thoughtful inventor, turning over these things in his mind, has, during the last few years, produced a wheel of novel construction, which is found practically to be superior to the one in common use. All the spokes, instead of being shouldered down to enter the stock, are made wedge-shaped at the end, and instead of the wheel being constructed from the centre to the felloe, it is constructed from the felloe to the centre. Every felloe is made and fitted with its two spokes, which, as they converge towards the centre, press upon each other in such a manner that when the whole periphery is put together a solid centre is produced by the spokes themselves, as shown in [Figs. 16 and 17]; so that instead of being dependent on wooden stocks the spokes are dependent upon each other, and by being tightly wedged together create a mutual support and resistance. The whole are secured by two metal flanges, one at the back and one at the front of the centre of the wheel, which are tightly screwed up, by which means the greatest amount of solidity is obtained for the entire structure of the wheel.

This invention is due to the Messrs. McNeile Brothers, of the Patent Steam Wheel and Axle Company, and it is a significant fact that wheels similarly constructed have for a considerable time been adopted by the Royal Artillery; moreover, they have been extensively used on street cabs, heavy carts, more particularly the latter, and have invariably maintained their character for superiority. For ourselves, we can see that a wheel so constructed must possess peculiar advantages. There is no stock to rot, and the wheel cannot in any sense be spoke-bound, as is frequently the case with wheels of ordinary construction, by the mortise in the stock and the bore in the felloe not ranging in a true line with the spoke. In the growing desire to produce wheels of light construction, great efforts have been made to reduce the size of the centre, and the inventors of these wheels have been very successful in obtaining this object. At the centre their wheels are exceedingly light and ornamental in appearance, and to render them still more uniform they have shortened the arm of their axles, and consequently curtailed the length of the axle-box, so that there is the smallest possible projection at the centre of the wheel. At the same time all the advantages and peculiarities of Collinge’s principle are retained. In the ordinary Collinge axle the bearing is not upon the whole length of the arm, and practically speaking Messrs. McNeile have in their axles cut out all that part which is useless in this respect, so that although their axle-arm is considerably shorter, the bearing is the same as in the Collinge axle of ordinary construction.

One of the greatest disadvantages in the manufacture of wheels is the want of uniformity between one another. Scarcely any two wheels are alike. Scarcely any spokes in a wheel radiate alike; some are as much as an inch apart more than others at the felloe; and as the shrinking of the tire varies, some wheels, as a consequence, get more dish than others, the spokes either compressing in the nave mortises, or yielding by elasticity in the direction of their length. To get them at all accurate, it is necessary to employ very skilful workmen, and as skilful workmen are not so numerous as they might be, the cost of wheels is very much increased. Another disadvantage attends them: a workman may put his work badly together, and there is no means of detecting it till the wheel is in actual use. A badly framed wheel will show as well to the eye as a good one, and until it breaks down, no one, whether maker or customer, can detect the inaccuracy. Unless the master watches every wheel while the spokes are driving he can only depend on the good faith of his workmen.

There is no remedy for this evil except substituting machines for men’s hands. The machine, if it cuts true once, will cut true always. Every piece of wood in a wheel ought to be shaped by machinery. The felloes should be sawn to their exact size, curve, and length by machine saws; they should be bored by machine augurs, and rounded by machine shavers. The spokes should be tenoned by machine saws, and shaped by machine lathes. The naves should be cut by a machine lathe, and the mortises in the same cut by a machine chisel. The spokes should not be driven in by the irregular strokes of a mallet, but be forced into their places by the regular pressure of a machine. And when the tire is put on the wheel should be fixed in a frame, in order to preserve an exact size and shape. When all these things are done, we may hope to procure wooden wheels alike in form and quality, and moreover, accurately circular, which very often they are not at present. All the machines should be worked by a steam engine. There is scarcely any article of manufacture for which there is so large a demand, and there is no great variation in their mode of construction. Coachmakers generally seem to cling to the old traditions of their craft with great tenacity; possibly they think it savours of sacrilege to let progress enter their workshops too rapidly.

Fig. 18.