In the Inventions Exhibitions may be seen a good form of metal wheel, the invention of Mr. H.J. Barrett, of Hull, Eng., and which we illustrate.
FIG. 1. FIG. 2. FIG. 3.
Fig. 1 is a perspective view of the wheel, Fig. 2 a transverse section, and Fig. 3 a longitudinal section of the boss. These wheels are made in two classes, A and B. Our engraving illustrates a wheel of the former class, these wheels being designed for use on rough and uneven roads, and when very great jolting strains may be met with, being stronger than those of class B design. The wheels are made with mild steel spokes, which are secured by metal straps in the recesses cut in the annular flanges on the boss, and by a taper bolt or rivet through the tire and rim. These spokes can be easily taken out and renewed when necessary by any unskilled person in a few minutes. The spokes being twisted midway of their length give greater strength to the wheel and power to resist side strains in pulling out of deep ruts or holes, without increasing the weight. The bosses and straps are made of malleable iron, in which the metal bushes are secured by means of a key with a washer screwed up on the front end. They are also fitted with steel oil caps to the end of the bushes, which are provided with a small set screw, so that the cap need not be taken off when it is necessary to lubricate the wheel, as by simply taking out the set screw oil may be poured through the hole into the cap.
The set screw also forms a fulcrum for a key, so that the cap can be taken off or put on when required, as well as a means of preventing the cap being lost by shaking loose on rough roads. In all hot and dry climates, the continued shrinking of wood wheels and loosening of the tires is a constant source of expense and inconvenience. This wheel having a tire and rim entirely of metal does away with the difficulty, as the expansion and contraction are equal, consequently the tires need only be removed when worn out, and others can be supplied, drilled complete, ready for putting on, which can be done by any unskilled person. The wheels of class B design are the same in principle of construction as those of class A, but they have cast metal bosses or naves, without loose bushes, and are suitable for general work and ordinary roads where the strains are not so severe. The bosses or naves are readily removed in case of breakage, and they can be fitted with steel oil caps for lubricating. - Iron.