A Solid-pneumatic Tire.
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The absorption of road shocks at the wheel rem or between the rim and the axle, is absolutely necessary, if a motor vehicle is to be operated successfully on ordinary roads. For light high-speed commercial vehicles, such as taxicabs, it has been found practically hopeless to attempt to run on wheels with standard-type solid-rubber tires : neither the passengers nor machinery can long tolerate the vibration, and, consequently, the wheels of practically every taxicab at present in public service are shod with the orthodox type of pneumatic tire. The immense importance of the tire problem has by no means been -overlooked, and numerous variations of the pneumatic type of tire have been produced from time to time, but without material divergence from custom on the part of users. In order to render the use of ordinary solid tires possible, special spring-mount Mg syskens, as well as flexible and nneumatie hubs, have been tried, some of them with a measure of success. Shock absorbers, too, of every description have been devised, but, in most cases, they have subsequently been abandoned, whilst the systematic evolving of spring-wheel devices by a certain class of inventor continues unabated. Few of these devices are afforded mention in the pages of this journal.
One tire, however, to which our attention has recently been drawn, calls for notice, at our hands, be
cause, it contains promise of practical results. We refer to the Evans-Doubleday tire, which is to be marketed as the "ED. solid-pneumatic" tire. It is claimed for this tire : that the life will be at least three times that; of an ordinary pneumatic ; that its first cost will be about the same as for a pneumatic that in smoothness of running it leaves little to be de
sired that it is puncture proof ; that. with au " El)." tire, a Stepney or spare wheel will never he necessary since, in the event of the solittiug of an inner tube, the tire may be run as a solid, until such time as a permanent repair may be effected : that it does not heat up so much as a pneumatic ; and that it has greater lateral stability.
The construction of the tire is clearly shown by the accompanying illustrations. Attached to the \voodeit felloo of the wheel, there is a steel rim of greater width than the ordinary rim. This rim.acte as a bond for the wheel felloes, and also serves as a bed on which the inner tube may bear : further; it locates the side flanges. On each side of the rim, and clamped to the sides of the felines by means of bolts and nuts, there are two pressed-steel side. flanges, one I-4 which is permanently fixed and the other is removable, so as to facilitate the mounting or dismounting of the tire. These flanges and the rim are stove-eun so as to obviate the possibility of damage to the rubber by rust. The inner tube is just an ordinary air tube provided with a valve, such as is used for the usual form of pneumatic tire. The solid part of the tire is constructed in one piece, but it really consists of two parts a nexibie band of canvas and rubber, which has a bead at each edge, and which provides for the inward movement against the air tube, and the tread, or wearing portion. The lower edges of the beads are extended, and are tapered off so as to form curtains which overlap the upturned edges of the steel rim, thereby affording protection for the inner tube, and guarding against the possibility of nipping. The tread consists of a very-tough quality of rubber, which rests on a narrow layer of red rubber. it is claimed by the maker that, when the tire has been worn down to this red band, it may be retreaded. The third layer, or base, of the solid portion of the tire is of a tougher and more-elastic quality of rubber.
The relative stability of the " El)." tire, as compared with an ordinary pneumatic, is shown by the two diagrams which we reproduce. As the tread of the tire meets with inequalities on the road surface, it is more or less depressed, causing flexure of the canvas base of the solid portion, and compressing the air in the inner tube in the manner of an ordinary pneumatic tire. The thick solid tread of the tire acts as a shock absorber, and the violent rebound which is inseparable from ordinary pneumatic tires e\ er bumpy roads is reduced very considerably. A number of these tires is now being tested to destruction, and, although these have not yet been running long enough to enable us to form a definite opinion as to their life, there is no reason to believe that will fail far short of 10,000 miles.
The " E.D." tire appears to be one for which owners of inottorcabs and small vans have long been waiting, viz., a pneumatic tire that can be used for vehicles of moderate weight with at least the same degree of economy as is obtainable with solid tires, whilst possessing a degree of elasticity comparable with that of pneumatics. If time and the exhaustive tests to which this make of tire is now being subjected support the claims advanced by the company, the practical value of the " E.D." the must quickly be appreciated by all users of light commercial vehicles.