GB626485A - Improvements in or relating to bicycles - Google Patents

Abstract

626,485. Tandem bicycles. DUGGAN, W. Aug. 28, 1946, No. 25691. [Class 136 (iii)] A tandem bicycle supports the additional saddle on a triangulated frame, the rear wheel axle having a crankshaft 29 provided with a second pair of cranks 28 power from which is transmitted by a chain 39 to the usual crank axle 15 which is connected in the usual way by a chain 37 to a sprocket wheel 36 on the rear hub, the rear wheel and sprocket wheel 36 are carried by anti friction bearings on a non-rotatable discontinuous rear wheel shaft, one part of which passes through the hub shell into and is mounted in one side of the rear wheel forks and another portion is mounted in the opposite side of the forks, the rear crankshaft passes through the rear wheel shaft and carries a second sprocket 41 which through the intermediary of the second chain drives a sprocket of the same size 40 secured to the main crankshaft. The bicycle has an auxiliary saddle 23 supported on forks 24 by a framework 13, 25, 26. The rear wheel shaft 30 is made in two parts 30a and 30b, the sprocket 36 is mounted on the part 30 which extends within the hub shell 35 and the sprocket 41 is mounted on the other part 30b. and is enclosed but for an exit gap 45 for the chain 39 by plates 42, 43, 44 which also connect the two parts of the wheel shaft. Axial adjustment of the rear wheel is effected by nuts 48 and 52. The tension of the chain 39 is adjusted by means of an idler sprocket 46 connected to the rear fork 14. To enable the horizontal fork 14 to be lengthened an extension bracket is connected to it carrying the forks 13, 24 and 26. The tandem bicycle can readily be converted into a solo bicycle.