A BENT WOOD WHEEL.
Page 17
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In this Wheel , Each Pair of Spokes Forms a U.
N INTERESTING type of wheel, examples of which are running on soitik_+ of London's omnibuses, has been produced by the Stagg Patent Wheel Co., Ltd., of Norwood Road, Herne Hill, London, S.E. They were actually built for this company by the Projectile and Engineering Co., Ltd., of New Road, Wandsworth Road, London, S.W...
The construction of tide wheel is such that it comes into two distinct categories, one based on the wheel being under compression, and the other on its being in tension.
The ordinary wheel is of the compression type, whilst the wire wheel, such as is used on bicycles and some motorcars, is of the tension type. The force exerted on the rim of a wheel When driving or braking always tends to move it in relation to the hub. This tendency is resisted by the spokes, and when these are of the ordinary radial type the tendency is to bend them at right angles. When the spokes are of the tension type, particularly if they he disposed on the tangential principle, the force does not aet at right angles to the spoke so that the force exerted on them is more compressive than transverse.
One of the prominent features Of the Stagg wheel is that the spokes are Ushaped. They thus not only give a considerable amount of resilience to the structure of the wheel, but enable the Strains to ,ltve transmitted tangentially from the hub to the felloe or vice versa.
Reference-to the drawing which we reproduce will show the method of fasten
ing the spokes in position. It will be seen that each pair is enclosed in an annular pocket farmed in the hub, as a matter of fact they are forced into position in gm hydraulic press, or other device capable of exerting considerable force. It will be seen that in the heavy type of wheel a double set of spokes is arranged so that the spokes of each set enter the rim alternately. The weakest point in many wheels is at the junction between each spoke arid the hub, but in the Stagg wheel this is one of the strongest points.
For front and other wheels bearing comparatively moderate loads, only one set of spokes is utilized.
The construction gives the wheel a, certain amount of elasticity, and ensures that the greatest advantage is taken of the natural strength of the wood in that it is never subjected to stresses in the wrong direction. This is said entirely to prevent any slackness developing.