A LOCAL INVENTION
PATENT BICYCLE CRANK,
Taking into consideration the weight, the symmetrical design, the almost frictionless, dust-proof ball-bearings, the perfect chains, the position of the rider, and last, but not least, the pneumatic tyre, the present-day bicycle _is about as perfect a piece of mechanism as it is possible \o imagine, and affords little or no room for further improvements. Nevertheless, hundreds of patents are taken out every week all over the world for improvements connected with the bicycle, the majority of which aim at the saving of power, and consequently the increasing of speed. These inventions took the form of speed gears, but up to the present have met •with little or no success, the manufacturers still retaining the ordinary driving gear. Every British and foreign cycling journal coming to hand contains accounts of patents relating to varying crankr, and inventors in applying their mind to this particular part ot the machine tacitly admit that this is the weak Bpot in the modern bicycle. So far tbesj patent cranks have not found favor with either the manufacturers or the general public—all being extremely complicated, DFr.»3sitating many alterations in the machine, and adding several pounds to its weight. However, notwithstanding the fact that so many inventors are in the field, there has recently been invented by Mr J. Dickinson, of Roslyn, Dunedin, and protected throughout the principal countries of the world, an extending and contracting crank that will fit any bicycle without adding more than a fewounces to its weight. All great inventions are noted for their simplicity, and this one is simplicity itself, the whole secret- being in fixing an eccentric on ball-bearing to the pedal. To give an idea of its action, we may say that when the pedal is at its highest point the.crank will measure Sin, or liin longer than thef average; and as the pedal descends the crank • gradually contracts until it reaches its lowest point, when it will measure 6£in, or i sin less than the average, and as th 6 I pedal riseß the crank gradually extends until it again measures Bin, a strong point being that the rider never knows he is on a shifting crank, the pedalling action being almost identical to that experienced on the present crank. All riders are aware that the chief drawback to long cranks is the great circle described by the feet, and the vast amount of power wasted in simply describing thh circle, and the inability of the average rider to' comfortably reach it; but with the new K cranks everybody can use them, as» the circle described is almost identical to that of an average length crank, but with the additional leverage of Thero is really no limit to the length that they may bo made to expaud and contract, it being quite possible to have a lOin crank contracting to 6|in, and on a long hill, where back pedalling is required, the rider by simply reversing his pedal reverses the whole aotion of the orank —l.e., the crank being ab its greatest length when tho pressure for back, pedalling is re. quired. Several ridera who have tried the cranks are unanimous in agreeing that they have a great future before them, and Mr R. Crow, whose experience dates over a large number of years, was so greatly taken with the invention when shown to him that he immediately acquired a share .in it at a considerable cost, and states that when properly made the weak point in the present day cycle will be overcome—that is, pedalling will be made easier —and that it will be only a matter of a short time before all first-class bicycles will be fitted with them.
A public trial will be given on the Caledonian Ground at an early date, when the cranks, which are at present in the hands of Messrs R. S. Tcnkinson and Co., will be fitted to one of their Viking racing machines geared to 96in, and all interested may have an opportunity of testing this important invention.
Permanent link to this item
A LOCAL INVENTION, Evening Star, Issue 10425, 21 September 1897