A New Form of Cast-steel Road Wheel:
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There is no need to remind our readers of the increased difficulties which have arisen since the outbreak of war in respect of the adequate supply of many classes of suitable steel castings. Reference to the well-known problems pertaining to the use of cast-steel road wheels, for example, need not again be made at the present. time. These are sufficiently familiar to warrant attention being given to any new and promising proposals with regard to them, which can be brought to the public notice.
In this connection, when recently calling upon Mr. Hugh A. 0. Adrain, British representative of the Georges Fischer Steel Works, of Schaffhouse, Switzerland, we were asked to examine his new range of patented designs for a. cast-steel road wheel with curved spokes. Mr. Adrain'a business address is 64, Fargate, Sheffield.
He, of course, is only too familiar with the many . difficulties which have arisen as between foundryman and vehicle owner in the development, of the modern Cast-steel road wheel, and it is, therefore, not Surprising to find that he has developed his design on
lines which are, at any rate, calculated to minimize the principal causes of failure, which have now so definitely been ascertained in the more usual classes of steel wheels.
It will be seen that the outstanding feature of the new design is the use once again of our old friend the curved spoke, thus reverting to a practice which has for many years been accepted as the correct one amongst founders and designers of east-iron flywheels and pulley wheels.
Mr. Adrain claims, of course, that the use of this curved spoke entirely obviates the difficulties arising from the unavoidable inequalities of cooling in connection with such a skeleton type of casting as that represented by the ordinary cast-steel road wheel. Once it becomes possible to eliminate the, state of stress which is induced, in such a casting as that which we are discussing, purely as the result of cooling, local fractures of the kind with which we are all familiar are extremely likely to disappear. This is a point which, of course, foundrymen above all will concede.
Mr. Adrain makes another point, which we do not remember to have seen emphasized in this connection before. He claims that, when a steel wheel "has been run on the road at. a high speed for a few miles, the rim gets hot, with the result that it expands and drags the spokes with it," with obvious results on Di 4 the whole structure. We think this heating effect due to running on the road is a negligible one, at any rate in connection with rubber-tired wheels. Were the tires part and parcel of the steel structure, the case would, of course, he different, but very few people so far have cared to risk the almost certain result of early fracture by running cast-steel wheels on the road without any resilient cushion intervening.
A great deal of this cast-steel work has of course hitherto been executed on the Continent, English makers seeming to fight shy of such delicate sections. Mr. Adrain thinks that it is very likely that English manufacturers will not have the same diffidence about tackling this class of work, with curved-spoke design to relieve them of some of their anxieties. At any rate the suggestion is an interesting one, and will no doubt serve to arouse discussion amongst users of this class of plant.
Activity in Roller Bearings.
No name is better known than Hoffmann's in the ball-bearing trade, but. there is every evidence to show that in a very short time an equal reputation will be ,s,nured by the roller bearing from the same factory.
We recently had occasion to visit the large and constantly expanding works of the Hoffmann Manufacturing Co., Ltd., at Chelmsford, and in. the course of a stroll through the different shops, we were surprised to see the enormous number of roller bearings going through the works. The Hoffmann roller bearing is distinctive in that a. comparatively short roller is employed, thus obviating any possibility Of wedging. The rollers nee held in a brass cage, while the inner and outer races are both flat.
Unduly rapid wear of ball bearings is frequently due to their being incorrectly mounted. It is, of course, well known that a bearing of this type will bear a small amount of end-thrust. Unfortunately, this capability has been_ considerably over-rated with. the unfortunate result referred to. We believe that one of the, incidental advanta,ges of the roller bearing is due to the fact that it is practically impossible to mount it in such a manner as to render it liable to the imposition of an endwise load. Probably from this cause alone longer life will result. Another point in connection with the new type of bearing which also has a bearing on the question of its mounting, refers to the necessity for correct alignment. It must be realized that whereas with the ball bearing a small amount of angularity in the shaft is permissible, nothing of the kind is possible with the roller bearing.
For commercial vehicles, the roller bearing, of course, is in favour with certain manufacturers. That builders are increasingly realizing its claims was shown by the large 'consignments bearing well-known names which awaited despatch.
The Hoffmann Manufacturing Co., Ltd., is at present working under difficulties, whiCh are being gradually overcome. At the outbreak of war, over 300 of of its 2000 men joined the Colours. Simultaneously, very large orders were received from the Government, in addition to a large increase of orders through ordinary trade channels. Extensions to the works were at once put in hand, and as soon as any part of these were rendered weatherproof, machines were installed and further work put in hand. in. a very short time the whole of the new shops will be open. The large demands of the Government and the shortage of labour have caused some delay in fulfilling some of the private orders, but in a very short space of time the Hoffmann Martufanturing Co.., Ltd., hopes to be able to deal with all orders with its usual expedient.
The company is, of course, an entirely British concern, but at such a time as the present it is necessary to lay stress on thispoint. The possession of a foreign-sounding name—as in this -ease—does not necessarily mean that the concern has either foreign capital or directors.